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Title:
POWDER COATING COMPOSITION, METHOD FOR PRODUCING COATED ARTICLE, AND COATED ARTICLE
Document Type and Number:
WIPO Patent Application WO/2020/065562
Kind Code:
A1
Abstract:
A powder coating composition includes (A) a first fluoropolymer, (B) a second fluoropolymer, (C) polyester, and (D) a curing agent. The number average molecular weight, Mn, of the first fluoropolymer (A) is greater than the number average molecular weight, Mn, of the second fluoropolymer (B). The hydroxyl number of the first fluoropolymer (A) is less than the hydroxyl number of the second fluoropolymer (B). The powder coating composition is able to form a film which is excellent in low glossiness and impact resistance. This disclosure provides a method of producing a coated article using the powder coating composition, and the coated article.

Inventors:
WANG HONGLI (US)
AIDA SHIGERU (US)
SAITO SHUN (CN)
Application Number:
PCT/IB2019/058148
Publication Date:
April 02, 2020
Filing Date:
September 25, 2019
Export Citation:
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Assignee:
AGC INC (JP)
International Classes:
C09D5/03; C08L67/00; C09D127/12
Foreign References:
JP2003171598A2003-06-20
JP2018059029A2018-04-12
EP0371599A21990-06-06
US20160160054A12016-06-09
US195461627362P
US199961628598P
JP2011012119A2011-01-20
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Claims:
CLAIMS

What is claimed is:

1. A powder coating composition comprising:

(A) a first fluoropolymer;

(B) a second fluoropolymer; wherein

the number average molecular weight, Mn, of said first fluoropolymer (A) is greater than the number average molecular weight, Mn, of said second fluoropolymer (B), and the hydroxyl number of said first fluoropolymer (A) is less than the hydroxyl number of said second fluoropolymer (B);

(C) polyester; and

(D) a curing agent.

2. The powder coating composition according to claim 1 , which satisfies Formula 1 :

Formula 1 : (Hydroxyl number of polyester (C) x Content mass of polyester (C)) > ((Hydroxyl number of the first fluoropolymer (A) x Content mass of the first fluoropolymer (A) + Hydroxyl number of the second fluoropolymer (B) x Content mass of the second fluoropolymer (B)).

3. The powder coating composition according to claim 1 or claim 2, wherein each of said first fluoropolymer (A) and said second fluoropolymer (B) comprises a fluoroalkylene based unit.

4. The powder coating composition according to any one of claims 1 to 3, wherein the difference between the hydroxyl number of said polyester (C) and the hydroxyl number of said second fluoropolymer (B) is 10 mg KOH/g or more.

5. The powder coating composition according to any one of claims 1 to 4, wherein the mass ratio of the content of said first fluoropolymer (A) to the content of said second fluoropolymer (B) is 0.25 to 99.

6. The powder coating composition according to claim 5, wherein the mass ratio of the content of said first fluoropolymer (A) to the content of said second fluoropolymer (B) is 1 to 49.

7. The powder coating composition according to any one of claims 1 to 6, wherein the difference between the hydroxyl number of said second fluoropolymer (B) and the hydroxyl number of said first fluoropolymer (A) is 20 mg KOH/g or more.

8. The powder coating composition according to any one of claims 1 to 6, wherein the difference between the hydroxyl number of said second fluoropolymer (B) and the hydroxyl number of said first fluoropolymer (A) is 300 mg KOH/g or less.

9. The powder coating composition according to any one of claims 1 to 8, wherein the mass ratio of the total content of said first fluoropolymer (A) and said second fluoropolymer (B) to the content of said polyester (C) is 0.1 to 10.0.

10. The powder coating composition according to claim 9, wherein the mass ratio of the total content of said first fluoropolymer (A) and said second fluoropolymer (B) to the content of said polyester (C) is 0.5 to 5.0.

11. The powder coating composition according to any one of claims 1 to 10, further comprising a pigment, wherein said pigment is titanium dioxide.

12. The powder coating composition according to claim 11, wherein the content of said titanium oxide is 10 parts by mass or more to a total of 100 parts by mass of said first fluoropolymer (A), said second fluoropolymer (B), and said polyester (C).

13. The powder coating composition according to any one of claims 1 to 12, wherein the pellet flow measured according to ASTM D 4242-02 is 30 to 150 mm.

14. The powder coating composition according to any one of claims 1 to 13, wherein the hydroxyl number of said first fluoropolymer (A) is less than 100 mg KOH/g, and the hydroxyl number of said second fluoropolymer (B) is 100 mg KOH/g or more.

15. The powder coating composition according to any one of claims 1 to 14, wherein said first fluoropolymer (A), said second fluoropolymer (B), and said polyester (C) comprise hydroxyl functional groups and said curing agent (D) is reactive with said hydroxyl functional groups of said first fluoropolymer (A), said second fluoropolymer (B), and said polyester (C).

16. The powder coating composition according to claim 15, wherein the total number of hydroxyl functional groups included in polyester (C) is greater than the total number of hydroxyl functional groups included in the first fluoropolymer (A) and the total number of hydroxyl functional groups included in the second fluoropolymer (B).

17. A method of producing a coated article, comprising:

applying said powder coating composition according to any one of claims 1 to 16 to a surface of a base material to form a paint layer; and

melt-curing said paint layer to form a film, thereby producing said coated article.

18. A coated article comprising a base material and a film formed from said powder coating composition according to any one of claims 1 to 16 put on a surface of said base material.

19. The coated article according to claim 18, having a surface fluorine to titanium (F/Ti) normalized atomic ratio ranging from 10.0 to 20.0 when said composition includes a pigment and said pigment is titanium dioxide.

20. The coated article according to claim 18 or claim 19, having specular gloss greater than 40 and less than 60 at 60°.

21. The coated article according to claim 18 or claim 19, having specular gloss less than 40 at

60°.

Description:
POWDER COATING COMPOSITION, METHOD FOR PRODUCING

COATED ARTICLE, AND COATED ARTICLE

[0001] The present application claims priority to and all the benefits of U.S. Patent Application No. 62/736,254, filed September 25, 2018, and U.S. Patent Application No. 62/859,899, filed June 11, 2019, which are hereby expressly incorporated by reference in their entirety.

FIELD OF THE DISCLOSURE

[0002] This disclosure generally relates to a powder coating composition. More specifically, this disclosure relates to a powder coating composition including first and second fluoropolymers (A) and (B), polyester (C), and a curing agent (D), a method for producing a coated article, and a coated article.

BACKGROUND

[0003] In recent years, in the fields of paints, powder paints (also known as powder coating compositions) that do not contain volatile organic compounds (VOC) are attracting attention in light of environmental protection. Among them, powder paints containing fluorine resin have been developed as paints improving the weather resistance properties and the like.

[0004] Furthermore, for the purpose of cost reduction and the like, a hybrid powder paint containing fluorine resin and non-fluorine resin has also been proposed. For example, Japanese Unexamined Patent Application Publication No. 2011-12119 describes a powder paint composition capable of obtaining a paint film in which fluorine resin and polyester resin are not compatibilized but separated into layers.

[0005] Powder paints are demanded for lowering the glossiness of paint film to be formed. When the powder paint composition according to Japanese Unexamined Patent Application Publication No. 2011-12119 was studied, the low glossiness of the paint film formed using the powder paint composition did not reach the required level. Moreover, paint film to be formed using a powder paint is also required to be excellent in impact resistance.

[0006] Accordingly, there exists a need to provide a powder coating composition (powder paint) which is able to form a film excellent in low glossiness and impact resistance, a method of producing a coated article using the powder coating composition, and a coated article.

SUMMARY OF THE DISCLOSURE AND ADVANTAGES

[0007] This disclosure provides a powder coating composition. The powder coating composition includes (A) a first fluoropolymer, (B) a second fluoropolymer, (C) polyester, and (D) a curing agent. The number average molecular weight, M n , of the first fluoropolymer (A) is greater than the number average molecular weight, M n , of the second fluoropolymer (B). The hydroxyl number of the first fluoropolymer (A) is less than the hydroxyl number of the second fluoropolymer (B).

[0008] This disclosure provides a method of producing a coated article using the powder coating composition, and the coated article.

[0009] The powder coating composition forms a film which is excellent in low glossiness and impact resistance as compared to typical films.

BRIEF DESCRIPTION OF THE FIGURES

[0010] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0011] Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: [0012] Figure 1 is a photograph obtained by observing a film formed from one embodiment of the composition of this disclosure as set forth in the Examples as Example 1 by SEM/EDX (a scanning electron microscope with an energy dispersive X-ray analyzer, TM3030 manufactured by Hitachi, Ltd.);

[0013] Figure 2 is a photograph obtained by observing a film formed from one embodiment of the composition of this disclosure as set forth in the Examples as Example 2 by SEM/EDX (a scanning electron microscope with an energy dispersive X-ray analyzer, TM3030 manufactured by Hitachi, Ltd.);

[0014] Figure 3 is a photograph obtained by observing a film formed from one embodiment of the composition of this disclosure as set forth in the Examples as Example 3 by SEM/EDX (a scanning electron microscope with an energy dispersive X-ray analyzer, TM3030 manufactured by Hitachi, Ltd.);

[0015] Figure 4 is a photograph obtained by observing a film formed from one embodiment of the composition of this disclosure as set forth in the Examples as Example 4 by SEM/EDX (a scanning electron microscope with an energy dispersive X-ray analyzer, TM3030 manufactured by Hitachi, Ltd.);

[0016] Figure 5 is a photograph obtained by observing a film formed from one embodiment of the composition of this disclosure as set forth in the Examples as Example 5 by SEM/EDX (a scanning electron microscope with an energy dispersive X-ray analyzer, TM3030 manufactured by Hitachi, Ltd.);

[0017] Figure 6 is a photograph obtained by observing a film formed from one embodiment of the composition of this disclosure as set forth in the Examples as Example 6 by SEM/EDX (a scanning electron microscope with an energy dispersive X-ray analyzer, TM3030 manufactured by Hitachi, Ltd.);

[0018] Figure 7 is a black and white image of Figure 1 ;

[0019] Figure 8 is a black and white image of Figure 2;

[0020] Figure 9 is a black and white image of Figure 3 ;

[0021] Figure 10 is a black and white image of Figure 4;

[0022] Figure 11 is a black and white image of Figure 5; and

[0023] Figure 12 is a black and white image of Figure 6.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0024] The meanings of the terms in the present invention are as follows.

[0025] (Meth)acrylate is a generic term for acrylate and methacrylate, and (meth)acrylic is a generic term for acrylic and methacrylic.

[0026] Unit is a generic term for an atomic group derived from one monomer molecule, which is directly formed by polymerization of the monomers, and an atomic group obtained by chemical conversion of a part of the atomic group. The content (mol%) of each unit relative to all the units included in a polymer is determined by analyzing the polymer with nuclear magnetic resonance spectroscopy.

[0027] Average particle size of the particles is the value of the 50% diameter determined by calculating the volume average from the particle size distribution measured using a known particle size distribution measuring apparatus (Sympatec, trade name: Helos-Rodos and the like) based on the laser diffraction method.

[0028] Glass transition temperature (T g ) is a midpoint glass transition temperature measured by differential scanning calorimetry (DSC) method. The glass transition temperature is also referred to as Tg. The Tg may be measured using a known differential scanning calorimeter (DSC) (rate of heating of lO°C per minute). The Tg may be obtained through drawing a tangent on the initial straight-line before baseline shifting and drawing another tangent on the slope. The crosspoint is the Tg value.

[0029] Weight average molecular weight and the number average molecular weight are values measured by gel permeation chromatography using polystyrene as a standard substance. The weight average molecular weight is also referred to as M w , and the number average molecular weight is also referred to as M n .

[0030] Acid value and hydroxyl number are values respectively measured according to the method of JIS K 0070-3 (1992). Hydroxyl number means or refers to the weight of potassium hydroxide (KOH) in milligrams corresponding to the hydroxyl groups in a 1 gram sample of a polyol. Hydroxyl number may also commonly be referred to as hydroxyl value. Hydroxyl number is interchangeable with hydroxyl value.

[0031] Film thickness is a value measured using an eddy current film thickness meter (SANKO Electronic Laboratory Co., Ltd., trade name: EDY-5000 and the like).

[0032] The disclosure of Howard & Howard Docket No. 065420.00119, entitled“Powder Coating Composition,” concurrently filed herewith and claiming priority from U.S. Patent Application No. 62/736,254, filed September 25, 2018, and U.S. Patent Application No. 62/859,899, filed June 11, 2019, is hereby expressly incorporated herein by reference in its entirety.

[0033] This disclosure provides a powder coating composition (hereinafter referred to as a “composition”). The composition may also commonly be referred to as a powder paint. The composition includes (A) a first fluoropolymer, (B) a second fluoropolymer, (C) polyester, and (D) a curing agent. The first fluoropolymer (A) and the second fluoropolymer (B) may also commonly be referred to as a first fluorine-containing polymer and a second fluorine-containing polymer, respectively. The number average molecular weight, M n , of the first fluoropolymer (A) is greater than the number average molecular weight, M n , of the second fluoropolymer (B). The hydroxyl number of the first fluoropolymer (A) is less than the hydroxyl number of the second fluoropolymer (B). The first fluoropolymer (A) may include a first fluoroalkylene based unit and a first unit having a hydroxyl functional group. The second fluoropolymer (B) may include a second fluoroalkylene based unit and a second unit having a hydroxyl functional group. The curing agent (D) may be reactive with the hydroxyl functional groups of the first and second fluoropolymers. Alternatively, the composition may consist essentially of or consist of (A), (B), (C), and (D). The terminology“consist essentially of’ describes embodiments wherein the composition may be free of one or more fluoropolymers that is not (A) and/or (B), may be free of a polyester that is not (C), and/or may be free of an agent that is not the curing agent (D), such as any described below.

[0034] Without being bound to any particular theory, it is believed that since the composition includes polyester (C) in addition to the first fluoropolymer (A) and the second fluoropolymer (B), when forming a film using the composition on a base material or substrate, the first fluoropolymer (A) and the second fluoropolymer (B) together and polyester (C) are easily phase separated. That is, the first fluoropolymer (A) and the second fluoropolymer (B) are likely placed on the surface side of the film (opposite to the base material/substrate side), and polyester (C) is likely placed on the base material/substrate side of the film. This phase separation is believed to be due to differential curing, described further below. In a film formed from the composition, an excellent impact resistance of the film formed from the composition is realized by the first fluoropolymer (A) and the second fluoropolymer (B) and polyester (C) being cured and fixed in the state of being placed as described above.

[0035] Furthermore, without being bound to any particular theory, since the composition includes the first fluoropolymer (A) and the second fluoropolymer (B) satisfying the relationship between the hydroxyl number and number average molecular weight, M n , (i.e., the hydroxyl number of the first fluoropolymer (A) is less than the hydroxyl number of the second fluoropolymer (B) and the M n of the first fluoropolymer (A) is greater than the M n of the second fluoropolymer (B)), it is believed that phase separation occurs when a film is formed, even between the first fluoropolymer (A) and the second fluoropolymer (B). It is believed that this phase separation is due to differential curing, described further below. It is also believed that such micro level phase separation, due to differential curing, realizes the low glossiness of the film formed from the composition.

[0036] The first fluoropolymer (A) is a polymer having a fluorine atom. The first fluoropolymer (A) includes a unit having a fluorine atom. The first fluoropolymer (A) includes a first fluoroalkylene based unit (hereinafter also referred to as unit F) as a unit having a fluorine atom. A fluoroalkylene is an olefin in which one or more of the hydrogen atoms have been substituted with fluorine atoms. The fluoroalkylene may also commonly be referred to as a fluoroolefin. In a fluoroalkylene, one or more hydrogen atoms which are not substituted with fluorine atoms may be substituted with chlorine atoms. In some embodiments, the carbon number of the fluoroalkylene based unit is 2 to 8, typically 2 to 6, and particularly typically 2 to 4. The first fluoropolymer (A) includes a first unit having a hydroxyl functional group described below.

[0037] The fluoroalkylene based unit may comprise a halo-fluoroalkyene based unit. The halo- fluoroalkylene based unit may be two, or more, of the same or different halo-fluoroalkylene based units. The halo- in halo-fluoroalkyene denotes any of the halogen atoms including fluorine, chlorine, bromine and iodine. For example, if the halogen atom is a chlorine atom, then the halo- fluoroalkylene is a chlorofluoroalkylene. If the halogen atom is a bromine atom, then the halo- fluoroalkylene is a bromofluoroalkylene and so on. Each of the halo-fluoroalkylene based units may independently include one or more halogen atoms, such as one, two or three halogen atoms, provided that at least one of the atoms in the halo-fluoroalkylene based unit is fluorine. This is due to the base unit being a fluoroalkylene based unit. In other embodiments, each of the halo- fluoroalkylene based units include two or more fluorine atoms, such as three, four, five or six fluorine atoms.

[0038] The number of carbon atoms in the halo-fluoroalkylene based unit is typically from 2 to 8, such as from 2 to 6, alternatively from 2 to 4. When the number of halo-fluoroalkylene based units is two, or more, of the same or different halo-fluoroalkylene based units, the number of carbon atoms in each of the halo-fluoroalkylene based units is typically independently from 2 to 8, such as from 2 to 6, alternatively from 2 to 4. When the number of carbon atoms is 2, the halo- fluoroalkyene based unit is a halo-fluoroethylene based unit. When the number of carbon atoms is 3, the halo-fluoroalkyene based unit is a halo-fluoropropylene based unit. The based unit may comprise additional fluorine atoms and additional halogens atoms as compared to the halo- fluoroethylene based unit. When the number of carbon atoms is 4, the halo-fluoroalkyene based unit is a halo-fluorobutylene based unit, and the base unit may comprise additional fluorine atoms and additional halogens atoms as compared to the halo-fluoroethylene based unit or the halo- fluoropropylene based unit.

[0039] In various embodiments, including when the at least one halo-fluoroalkylene based unit is two, or more, of the same or different halo-fluoroalkylene based units, each of the fluoroalkylene based units may include tetrafluoroethylene (TFE) based units, chlorotrifluoroethylene (CTFE) based units, hexafluoropropylene based units, vinylidene fluoride based units, vinyl fluoride based units, polyvinylidene fluoride (PVDF) based units, ethylene tetrafluoroethylene (ETFE) based units, ethylene chlorotrifluoroethylene (ECTFE) based units, polymers of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (THV), and combinations thereof. In various embodiments, each of the based units of fluoroalkylene may include chlorotrifluoroethylene (CTFE) based units. In various embodiments, all of the units attributed to the fluoroalkylene based unit in the first fluoropolymer (A) are the same. In various embodiments, all of the units attributed to the fluoroalkylene based unit in the second fluoropolymer (B) are the same.

[0040] Specific examples of fluoroalkylene based units include CF2=CF 2 , CF 2 =CFCl, CF 2 =CFlF, CH 2 =CF 2 , CF 2 =CFCF 3 , CF 2 =CHCF 3 , CF 3 CH=CHF, CF 3 CF=CH 2 , and monomers represented by a formula CH 2 =CX fl (CF 2 ) ni Y fl . In the formula, X fl and Y fl are independently a hydrogen atom or a fluorine atom, and nl is an integer from 2 to 10.

[0041] In some embodiments, fluoroalkylene based units are CF 2 =CF 2 , CH 2 =CF 2 , CF 2 =CFCl, CF 3 CH=CHF, and CF 3 CF=CH 2 in light of the weather resistance of a film formed from the composition, CF 2 =CF 2 , typically CH 2 =CF 2, and CF 2 =CFCl, and more particularly CF 2 =CFCl. Two or more types of fluoroalkylene based units may be used in combination.

[0042] The first fluoropolymer (A) may include only the unit F as a unit having a fluorine atom. The first fluoropolymer (A) may include a unit based on a monomer including a fluorine atom other than a fluoroalkylene based unit. The first fluoropolymer (A) may include both a unit based on a monomer including a fluorine atom other than a fluoroalkylene based unit and unit F.

[0043] The content of unit F relative to all the units included in the first fluoropolymer (A) may be 20 to 80 mol%. In some embodiments, the content of unit F is 30 to 70 mol%, and typically 40 to 60 mol% in light of the weather resistance of a film formed from the composition. [0044] The first fluoropolymer (A) includes a first unit having a hydroxyl functional group (hereinafter also referred to as a unit H). A hydroxyl functional group may also commonly be referred to as a hydroxy group or hydroxy. Specific examples of unit H include a unit based on a monomer having a hydroxyl functional group and a unit in which at least a part of the reactive group that the first fluoropolymer (A) has in the side chain is converted to a hydroxyl functional group, for example, a unit having a hydroxyl functional group obtained by deprotecting a protecting group such as an alkoxy group. Unit H preferably does not have a fluorine atom in light of the polymerizability of the first fluoropolymer (A).

[0045] Specific examples of the monomer having a hydroxyl functional group include vinyl ether, vinyl ester, allyl ether, allyl ester, (meth)acrylic ester, and allyl alcohol having a hydroxyl functional group. Units based on these monomers may be used.

[0046] Specific examples of the monomer having a hydroxyl functional group include CH2=CHO- CH 2 -cycloC 6 Hio-CH 2 0H, Cl^CHClUO-ClU-cycloCeHio-ClUOH, CH2=CHOCH2CH 2 OH, CH 2 =CHCH 2 0CH 2 CH 2 0H, CH 2 =CHOCH 2 CH2CH2CH2OH, and

CH 2 =CHCH 2 0CH 2 CH 2 CH 2 CH 2 0H. In some embodiments, the monomer having a hydroxyl functional group is Cl^CHClUOClUClUOH or CH 2 =CHOCH2CH2CH2CH 2 OH in light of copolymerizability with a fluoroalkylene. The term“-cycloC 6 Hio-” represents a cyclohexylene group, and the binding site of“-cyclo C 6 H IO -” is usually 1,4-. Two or more types of monomers having a hydroxyl functional group may be used in combination.

[0047] The alkyl vinyl ether based unit may comprise a combination of at least one cycloalkyl vinyl ether based unit and at least one hydroxyalkyl vinyl ether based unit. The alkyl vinyl ether based unit may be two, or more, of the same or different alkyl vinyl ether based units. The cycloalkyl vinyl ether based unit may be two, or more, of the same or different cycloalkyl vinyl ether based units. The hydroxyalkyl vinyl ether based unit may be two, or more, of the same or different hydroxyalkyl vinyl ether based units. The hydroxyl functional groups are present in units attributed to the at least one alkyl vinyl ether based unit, such as the hydroxyalkyl vinyl ether based units, although not all of these alkyl vinyl ether units include the hydroxyl functional groups. In various embodiments, each of the units attributed to the cycloalkyl vinyl ether based units do not have any reactive group, e.g., do not have any hydroxyl functional groups.

[0048] The number of carbon atoms in each of the alkyl groups in the alkyl vinyl ether based unit, including in the at least one cycloalkyl vinyl ether based unit and in the at least one hydroxyalkyl vinyl ether based unit, is typically independently from 2 to 20, such as from 2 to 10, alternatively from 2 to 8. When the at least one alkyl vinyl ether based unit is two, or more, of the same or different alkyl vinyl ether based units, the number of carbon atoms in each of the alkyl groups in each of the alkyl vinyl ether based units is typically independently from 2 to 20, such as from 2 to 10, alternatively from 2 to 8. When the cycloalkyl vinyl ether based unit is two, or more, of the same or different cycloalkyl vinyl ether based units, the number of carbon atoms in each of the alkyl groups in each of the cycloalkyl vinyl ether based units is typically independently from 2 to 20, such as from 2 to 10, alternatively from 2 to 8. When the hydroxyalkyl vinyl ether based unit may be two, or more, of the same or different hydroxyalkyl vinyl ether based units, the number of carbon atoms in each of the alkyl groups in each of the hydroxyalkyl vinyl ether based units is typically independently from 2 to 20, such as from 2 to 10, alternatively from 2 to 8.

[0049] In various embodiments, including when the cycloalkyl vinyl ether based unit is two, or more, of the same or different cycloalkyl vinyl ether based units, each of the cycloalkyl vinyl ether based units may include cyclohexyl vinyl ether (CHVE) based units, cyclopentyl vinyl ether based units, cyclobutyl vinyl ether based units, or combinations thereof. In various embodiments, all of the units attributed to the at least one cyclovinyl ether based unit in the first fluoropolymer (A) are the same. In various embodiments, all of the units attributed to the at least one cyclovinyl ether based unit in the second fluoropolymer (B) are the same.

[0050] In various embodiments, each of the hydroxyalkyl vinyl ether based units may have linear or branched alkyl groups. In various embodiments, including when the at least one hydroxyalkyl vinyl ether based unit is two, or more, of the same or different hydroxyalkyl vinyl ether based units, each of the hydroxyalkyl vinyl ether based units may include 4-hydroxybutyl vinyl ether (HBVE) based units, 2-hydroxyethyl vinyl ether based units, cyclohexanediol monovinyl ether based units, hydroxypentyl vinyl ether based units, hydroxyhexyl vinyl ether based units, or combinations thereof. In various embodiments, all of the units attributed to the at least one hydroxyalkyl vinyl ether based unit in the first fluoropolymer (A) are the same. In various embodiments, all of the units attributed to the at least one hydroxyalkyl vinyl ether based unit in the second fluoropolymer (B) are the same.

[0051] In various embodiments, the halo-fluoroalkylene based unit comprises at least one chlorotrifluoroethylene (CTFE) based unit and the alkyl vinyl ether based unit comprises a combination of at least one cycloalkyl vinyl ether based unit including at least one cyclohexyl vinyl ether (CHVE) based unit and at least one hydroxyalkyl vinyl ether based unit including at least one 4-hydroxybutyl vinyl ether (HBVE) based unit.

[0052] Alternating units attributed to the at least one fluoroalkylene based unit and at least one alkyl vinyl ether based unit in the second fluoropolymer (B) are the same as described above with respect to the alternating units attributed to the at least one fluoroalkylene based unit and at least one alkyl vinyl ether based unit in the first fluoropolymer (A). [0053] In some embodiments, the content of unit H relative to all the units included in the first fluoropolymer (A) is 1 to 30 mol%, typically 3 to 25 mol%, and particularly typically 5 to 15 mol%.

[0054] In some embodiments, the first fluoropolymer (A) further includes a unit having no hydroxyl functional group and no fluorine atom (hereinafter also referred to as a unit D) in order to adjust the film physical properties of a film formed from the composition. In some embodiments, unit D is a unit based on a monomer having no hydroxyl functional group and no fluorine atom (hereinafter also referred to as a monomer D).

[0055] Specific examples of the monomer D include alkene, vinyl ether, vinyl ester, allyl ether, allyl ester, and (meth)acrylic ester. In some embodiments, the monomer D is vinyl ether or vinyl ester in light of the polymerizability with the monomer having a fluorine atom. The monomer D may have a cross-linkable group other than a hydroxyl functional group. Specific examples of such a cross-linkable group include a carboxy group, an amino group, an alkoxysilyl group, and an epoxy group. Specific examples of the monomer D include ethylene, propylene, 1 -butene, ethyl vinyl ether, 2-ethylhexyl vinyl ether, vinyl acetate, vinyl versatate, and vinyl neodecanoate. Two or more types of the monomer D may be used in combination.

[0056] In light of the Tg of the first fluoropolymer (A) being improved and the blocking resistance of the composition being improved, at least a part of the monomer D may be a monomer Dl represented by a formula X^Z 1 . X 1 is CH 2 =CHC(0)0-, CH 2 =C(CH 3 )C(0)0-, CH 2 =CHOC(0)-, CH 2 =CHCH 2 0C(0)-, CH 2 =CHO-, or CH 2 =CHCH 2 0-. In light of polymerizability with a monomer having a fluorine atom, X 1 may be CH 2 =CHOC(0)-, CH 2 =CHCH 2 0C(0)-, CH 2 =CHO- , and CH 2 =CHCH 2 0-. In some embodiments, X 1 may be CH 2 =CHOC(0)-, CH 2 =CHO-, and CH 2 =CHCH 2 0C(0)-. Z 1 is an alkyl group of the carbon number 4 to 8 represented by a formula -C(Z R1 ) 3 . However, three Z R1 are each independently an alkyl group of the carbon number 1 to 5, a cycloalkyl group of the carbon number 6 to 10, a cycloalkyl alkyl group of the carbon number 6 to 10, an aryl group of the carbon number 6 to 10, or an aralkyl group of the carbon number 7 to 12. Among them, in light of the weather resistance of a film formed from the composition, an alkyl group may be of the carbon number 4 to 8 represented by a formula -C(Z R 1 ) ¾ and a cycloalkyl group may be of the carbon number 6 to 10.

[0057] The group represented by the formula -C(Z R I )¾ has a structure having a tertiary carbon atom in which three groups represented by the formula Z R1 are bound to“C (carbon atom)” specified in this formula, and the group is directly bound to the group represented by the formula X 1 . In some embodiments, the three Z R1 may be all methyl groups, or one is a methyl group, and the remaining two are each independently an alkyl group of the carbon number 2 to 5, or two are methyl groups, and one is an alkyl group of the carbon number 3 to 5. When one is a methyl group, and the remaining two are each independently an alkyl group of the carbon number 2 to 5, the total number of the carbon atoms of the remaining two of the three Z R1 may be 4 to 6. The group represented by the formula -C(Z R 1 ) ¾ may be a tert-butyl group and a tertiary alkyl group in which two of the groups represented by Z R1 are methyl groups and one is an alkyl group of the carbon number 3 to 5. A cycloalkyl group may be a cyclohexyl group. A cycloalkyl alkyl group may be a cyclohexylmethyl group. An aralkyl group may be a benzyl group. An aryl group may be a phenyl group or a naphthyl group, or typically a only phenyl group. A hydrogen atom of the cycloalkyl group, the cycloalkyl alkyl group, the aryl group, and the aralkyl group may be substituted with an alkyl group. In this case, the carbon number of the alkyl group as a substituent is not included in the carbon number of the cycloalkyl group and the aryl group. Specific examples of the monomer Dl include cyclohexyl vinyl ether, vinyl pivalate, vinyl neononanoate, vinyl benzoate, tert-butyl vinyl ether, tert-butyl (meth)acrylate, and benzyl (meth)acrylate. Two or more types of the monomer D 1 may be used in combination.

[0058] The content of unit D when the first fluoropolymer (A) includes unit D may be 5 to 60 mol%, typically 20 to 50 mol%, and particularly typically 30 to 45 mol% relative to all the units included in the first fluoropolymer (A). The content of the unit based on the monomer Dl when the first fluoropolymer (A) and the second fluoropolymer (B) include units based on the monomer Dl among units D may be 5 to 60 mol%, typically 20 to 50 mol%, and particularly typically 30 to 45 mol%, relative to all the units included in the first fluoropolymer (A) and the second fluoropolymer (B) in light of the Tg of the first fluoropolymer (A) and the second fluoropolymer (B) being improved.

[0059] The first fluoropolymer (A) may include unit F, unit H, and unit D at 20 to 80 mol%, 1 to 30 mol%, and 5 to 60 mol% in this order, relative to all the units included in the first fluoropolymer (A), and typically, it includes at 40 to 60 mol%, 5 to 15 mol%, and 30 to 45 mol%.

[0060] In some embodiments, the first fluoropolymer (A) includes a reaction product of at least one fluoroalkylene based unit and at least one alkyl vinyl ether based unit and also includes hydroxyl functional groups. The first fluoropolymer (A) may be a reaction product of a polymerization reaction in which the reactants include the at least one fluoroalkylene based unit, the at least one alkyl vinyl ether based unit, and a polymerization initiator. The polymerization initiator is not particularly limited and may be any known in the art. Examples of the polymerization initiator include, but are not limited to, azo initiators such as 2,2'- azobisisobutyronitrile, 2,2'-azobiscyclohexane carbonatenitrile, 2,2'-azobis(2,4- dimethylvaleronitrile), and 2,2'-azobis(2-methylbutyronitrile); and peroxide initiators such as cyclohexanone peroxide and the like ketone peroxides, tert-butyl hydroperoxide and the like hydroperoxides, benzoyl peroxide and the like diacyl peroxide; di-tert-butyl peroxide and the like dialkyl peroxides, 2,2-di-(tert-butylperoxy)butane and the like peroxyketals, tert-butyl peroxypivalate (PBPV) and the like alkyl peresters, and diisopropyl peroxydicarbonate and the like percarbonates. During the polymerization reaction, the at least one fluoroalkylene based unit forms units and the at least one alkyl vinyl ether based unit forms units. These units link together in an alternative manner during the polymerization reaction to form the first fluoropolymer (A). As a result of the polymerization reaction, the first fluoropolymer (A) includes units formed from, or attributed to, the at least one fluoroalkylene based unit alternating with units formed from, or attributed to, the at least one alkyl vinyl ether based unit. The first fluoropolymer (A) may be called a fluoro-ethylene / vinyl ether copolymer or alternatively may be called a FEVE polymer. Alternatively, the first fluoropolymer (A) may consist of or consist essentially of the reaction product of at least one fluoroalkylene based unit and at least one alkyl vinyl ether based unit and the hydroxyl functional groups. The at least one fluoroalkylene based unit may be two, or more, of the same or different fluoroalkylene based units. The at least one alkyl vinyl ether based unit may be two, or more, of the same or different alkyl vinyl ether based units. The hydroxyl functional groups are present in the units attributed to the at least one alkyl vinyl ether based unit, although not all of these alkyl vinyl ether units including the hydroxyl functional groups.

[0061] The reaction product of the first fluoropolymer (A) has a higher mole % of units attributed to the at least one cycloalkyl vinyl ether based unit than the another reaction product of the second fluoropolymer (B). A mole % of units attributed to the at least one cycloalkyl vinyl ether based unit in the reaction product of the first fluoropolymer (A) ranges from 35 to 45 mole % based on the first fluoropolymer (A). A mole % of units attributed to the at least one cycloalkyl vinyl ether based unit in the another reaction product of the second fluoropolymer (B) ranges from 20 to 30 mole % based on the second fluoropolymer (B). The higher mole % of these cycloalkyl vinyl ether units in the first fluoropolymer (A) may provide the first fluoropolymer (A) with a higher viscosity than the second fluoropolymer (B).

[0062] In various embodiments, the first fluoropolymer (A) includes units attributed to at least one cyclohexyl vinyl ether (CHVE) based unit in a typical range of from 35 to 45 mole % based on the first fluoropolymer (A), more typically from 37 to 43 mole %, and particularly typically from 38 to 41 mole %, or 38 to 40 mole %. The at least one cyclohexyl vinyl ether (CHVE) based unit may include two, or more, cyclohexyl vinyl ether (CHVE) based units. The mole % of these cyclohexyl vinyl ether (CHVE) units in the first fluoropolymer (A) may be about, or is, 39 mole %. In alternative embodiments, the first fluoropolymer (A) consists of, or consists essentially of, these cyclohexyl vinyl ether (CHVE) units in a range of from 35 to 45 mole % based on the first fluoropolymer (A), more typically from 37 to 43 mole %, and particularly typically from 38 to 41 mole %, or 38 to 40 mole %.

[0063] The reaction product of the first fluoropolymer (A) has a lower mole % of units attributed to the at least one hydroxyalkyl vinyl ether based unit than the another reaction product of the second fluoropolymer (B). A mole % of the units attributed to the at least one hydroxyalkyl vinyl ether based unit in the reaction product of the first fluoropolymer (A) ranges from 5 to 15 mole % based on the first fluoropolymer (A). A mole % of the units attributed to the at least one hydroxyalkyl vinyl ether based unit in the another reaction product of the second fluoropolymer (B) ranges from 20 to 30 mole % based on said second fluoropolymer (B). The lower mole % of these hydroxyalkyl vinyl ether units in the first fluoropolymer (A) may provide the first fluoropolymer (A) with a lower functionality, such as a lower reactive functionality, than the second fluoropolymer (B), for example, with a lower hydroxyl functionality than the second fluoropolymer (B).

[0064] In various embodiments, the first fluoropolymer (A) includes units attributed to at least one 4-hydroxybutyl vinyl ether (HBVE) based unit in a typical range of from 5 to 15 mole % based on the first fluoropolymer (A), more typically from 7 to 13 mole %, and particularly typically from 9 to 12 mole %, or 10 to 12 mole %. The at least one 4-hydroxybutyl vinyl ether (HBVE) based unit may include two, or more, 4-hydroxybutyl vinyl ether (HBVE) based units. The mole % of these 4-hydroxybutyl vinyl ether (HBVE) units in the first fluoropolymer (A) may be about, or is, 11 mole %. In alternative embodiments, the first fluoropolymer (A) consists of, or consists essentially of, these 4-hydroxybutyl vinyl ether (HBVE) units in a range of from 5 to 15 mole % based on the first fluoropolymer (A), more typically from 7 to 13 mole %, and particularly typically from 9 to 12 mole %, or 10 to 12 mole %.

[0065] It is contemplated that units attributed to the at least one fluoroalkylene based unit provide excellent ultra-violet stability, durability, abrasion resistance, weather resistance, and chemical resistance. It is contemplated that units attributed to the at least one alkyl vinyl ether based unit provide solvent compatibility and cross-linking sites for cross-linking with the curing agent (D). The combination of these fluoroalkylene units and these alkyl vinyl ether units in each of the first fluoropolymer (A) and the second fluoropolymer (B) may be used to provide a film formed from curing the composition that has excellent surface smoothness and improved weather resistance, low glossiness, adhesion, and blocking resistance. Additionally, when a pigment is used in the composition, the film exhibits low pigment, such as titanium dioxide, at the film surface and exhibits minimal orange peel and/or surface roughness. [0066] The Tg of the first fluoropolymer (A) may be 40 to l20°C, typically 45 to l00°C, and particularly typically 50 to 80°C. In various embodiments, the Tg of the first fluoropolymer (A) ranges from 50 to 60 °C, typically from 50 to 57 °C or 52 to 55 °C. The Tg of the first fluoropolymer may be about, or is, 52 °C or 55 °C. The T g of the first fluoropolymer (A) provides improved blocking resistance or blocking suppression to a film formed from the composition and also provides improved surface smoothness and hardness to the resulting film. It is advantageous if the Tg does not drop below about 35 to 40 °C so that the first fluoropolymer (A) does not deteriorate or agglomerate during transportation or storage.

[0067] The M n of the first fluoropolymer (A) is greater than the M n of the second fluoropolymer (B) described later. The M n of the first fluoropolymer (A) being greater than the M n of the second fluoropolymer (B) may provide the composition with a viscosity and/or flowability during curing that provides the resulting film with excellent surface smoothness, low glossiness, impact resistance, water resistance and/or salt water resistance. The M n of the first fluoropolymer (A) may be 7,500 to 50,000, typically 7,500 to 22,500, and typically 8,000 to 20,000, or 10,000 to 20,000. The M n of the first fluoropolymer (A) particularly typically ranges from 12,500 to 17,500, 13,500 to 16,500, and more particularly typically ranging from 14,500 to 15,500.

[0068] The hydroxyl number of the first fluoropolymer (A) is less than the hydroxyl number of the second fluoropolymer (B) described later. The hydroxyl number of the first fluoropolymer (A) may be more than 0 and less than 80 mg KOH/g, typically 15 to 70 mg KOH/g, and particularly typically 30 to 60 mg KOH/g. In some embodiments, the hydroxyl number of the first fluoropolymer (A) typically ranges from 30 to 60 mgKOH/g, or 35 to 55, particularly typically ranging from 40 to 50, and more particularly typically ranging from 42 to 48. [0069] The first fluoropolymer (A) may have an acid value. The acid value may be 50 mg KOH/g or less, typically 1 mg KOH/g or less, and particularly typically 0.1 mg KOH/g or less.

[0070] The second fluoropolymer (B) is a polymer having a fluorine atom. The second fluoropolymer (B) includes a unit having a fluorine atom. The second fluoropolymer (B) includes a second fluoroalkylene based unit as a unit having a fluorine atom. The second fluoropolymer (B) includes a second unit having a hydroxyl functional group.

[0071] As the unit having the fluoroalkylene based unit included in the second fluoropolymer (B), a unit having a fluorine atom which may be used in the first fluoropolymer (A) (unit F and the like) may be used in the same manner, and it is the same in some embodiments.

[0072] As the second unit having a hydroxyl functional group included in the second fluoropolymer (B), unit H which may be used as the first unit in the first fluoropolymer (A) may be used in the same manner, and it is the same in some embodiments.

[0073] The second fluoropolymer (B) may include a unit based on a monomer having no hydroxyl functional group and no fluorine atom, and as such a unit, the unit D which may be used in the first fluoropolymer (A) may be used in the same manner, and it is the same for some embodiments.

[0074] In the second fluoropolymer (B), the content of unit F may be 20 to 80 mol%, typically 30 to 70 mol%, and particularly typically 40 to 60 mol% relative to all the units included in the second fluoropolymer (B) in light of the weather resistance of a film formed from the composition.

[0075] The content of unit H may be 5 to 50 mol%, typically 10 to 40 mol%, and particularly typically 20 to 35 mol% relative to all the units included in the second fluoropolymer (B).

[0076] The content of unit D (in some embodiments unit Dl) when the second fluoropolymer (B) includes unit D (in some embodiments unit Dl) may be 5 to 60 mol%, typically 10 to 50 mol%, and particularly typically 15 to less than 30 mol% relative to all the units included in the second fluoropolymer (B).

[0077] The second fluoropolymer (B) may include unit F, unit H, and unit D at 20 to 80 mol%, 5 to 50 mol%, and 5 to 60 mol% in this order relative to all the units included in the second fluoropolymer (B), and typically, it includes at 40 to 60 mol%, 20 to 35 mol%, and no less than 15 and less than 30 mol%, respectively.

[0078] In some embodiments, the second fluoropolymer (B) includes another reaction product of at least one fluoroalkylene based unit and at least one alkyl vinyl ether based unit and also includes hydroxyl functional groups. The second fluoropolymer (B) may be a reaction product of a polymerization reaction in which the reactants include the at least one fluoroalkylene based unit, the at least one alkyl vinyl ether based unit, and a polymerization initiator. The polymerization initiator may be that which may be used in the first fluoropolymer (A) and may be used in the same manner, and it is the same in some embodiments. During the polymerization reaction, the at least one fluoroalkylene based unit forms units and the at least one alkyl vinyl ether based unit forms units. These units link together in an alternative manner during the polymerization reaction to form the second fluoropolymer (B). As a result of the polymerization reaction, the second fluoropolymer (B) includes units formed from, or attributed to, the at least one fluoroalkylene based unit alternating with units formed from, or attributed to, the at least one alkyl vinyl ether based unit. The second fluoropolymer (B) may be called a fluoro-ethylene / vinyl ether copolymer or alternatively may be called a FEVE polymer. Alternatively, the second fluoropolymer (B) may consist of or consist essentially of the reaction product of at least one fluoroalkylene based unit and at least one alkyl vinyl ether based unit and the hydroxyl functional groups. The at least one fluoroalkylene based unit may be two, or more, of the same or different fluoroalkylene based units. The at least one alkyl vinyl ether based unit may be two, or more, of the same or different alkyl vinyl ether based units. The hydroxyl functional groups are present in the units attributed to the at least one alkyl vinyl ether based unit, although not all of these alkyl vinyl ether units including the hydroxyl functional groups.

[0079] In various embodiments, the second fluoropolymer (B) includes units attributed to at least one cyclohexyl vinyl ether (CHVE) based unit in a typical range of from 20 to 30 mole % based on the second fluoropolymer (B), more typically from 21 to 29 mole %, and particularly typically from 22 to 28 mole %, or 24 to 26 mole %. The at least one cyclohexyl vinyl ether (CHVE) based unit may include two, or more, cyclohexyl vinyl ether (CHVE) based units. The mole % of these cyclohexyl vinyl ether (CHVE) units in the second fluoropolymer (B) may be about, or is, 25 mole %. In alternative embodiments, the second fluoropolymer (B) consists of, or consists essentially of, these cyclohexyl vinyl ether (CHVE) units in a range of from 20 to 30 mole % based on the second fluoropolymer (B), more typically from 21 to 29 mole %, and particularly typically from 22 to 28 mole %, or 24 to 26 mole %.

[0080] In various embodiments, the second fluoropolymer (B) includes units attributed to at least one 4-hydroxybutyl vinyl ether (HBVE) based unit in a typical range of from 20 to 30 mole % based on the second fluoropolymer (B), more typically from 21 to 29 mole %, and particularly typically from 22 to 28 mole %, or 24 to 26 mole %. The at least one 4-hydroxybutyl vinyl ether (HBVE) based unit may include two, or more, 4-hydroxybutyl vinyl ether (HBVE) based units. The mole % of these 4-hydroxybutyl vinyl ether (HBVE) units in the second fluoropolymer (B) may be about, or is, 25 mole %. In alternative embodiments, the second fluoropolymer (B) consists of, or consists essentially of, these 4-hydroxybutyl vinyl ether (HBVE) units in a range of from 20 to 30 mole % based on the second fluoropolymer (B), more typically from 21 to 29 mole %, and particularly typically from 22 to 28 mole %, or 24 to 26 mole %.

[0081] Units attributed to the at least one fluoroalkylene based unit are independently at least 35 mole % of each of the reaction product of the first fluoropolymer (A) and the another reaction product of the second fluoropolymer (B). The at least one fluoroalkylene based unit may include two, or more, of the same or different fluoroalkylene based units. In various embodiments, these fluoroalkylene units comprise units attributed to at least one chlorotrifluoroethylene (CTFE) based unit in both the first and second fluoropolymers (A) and (B). The at least one chlorotrifluoroethylene (CTFE) based unit may include two, or more, chlorotrifluoroethylene (CTFE) based units. In various embodiments, the mole ratio of units attributed to the at least one fluoroalkylene based unit of the reaction product of the first fluoropolymer (A) to units attributed to the at least one fluoroalkylene based unit of the another reaction product of the second fluoropolymer (B) ranges from 40:60 to 60:40, typically 45:55 to 55:45. In various embodiments, the units attributed to the at least one chlorotrifluoroethylene (CTFE) based units are independently at least 50 mole % of each of the reaction product of the first fluoropolymer (A) and the another reaction product of the second fluoropolymer (B). In various embodiments, the mole ratio of the units attributed to the at least one chlorotrifluoroethylene (CTFE) based unit of the reaction product of the first fluoropolymer (A) to the units attributed to the at least one chlorotrifluoroethylene (CTFE) based unit of the another reaction product of the second fluoropolymer (B) is 50:50.

[0082] The Tg of the second fluoropolymer (B) may be 20 to 80°C, typically 30 to 60°C, and particularly typically no less than 35 and less than 50°C. In various embodiments, the Tg of the second fluoropolymer (B) ranges from 40 to 50 °C, typically from 41 to 49 °C or 43 to 47 °C. The Tg of the second fluoropolymer may be about, or is, 45 °C. The Tg of the second fluoropolymer (B) provides improved blocking resistance or blocking suppression to a film formed from the composition and also provides improved surface smoothness and hardness to the resulting film. It is advantageous if the Tg does not drop below about 35 to 40 °C so that the second fluoropolymer (B) does not deteriorate or agglomerate during transportation or storage.

[0083] The M n of the first fluoropolymer (A) is greater than the M n of the second fluoropolymer (B). Said differently, the M n of the second fluoropolymer (B) is less than the M n of the first fluoropolymer (A) described above. The M n of the second fluoropolymer (B) may be 2,000 to 30,000 and typically greater than 4,000 and less than 8,000. The M n of the second fluoropolymer (B) typically ranges from 5,000 to 10,000, or 5,500 to 9,500, particularly typically ranging from 6,000 to 9,000, 6,500 to 8,500, and more particularly typically ranging from 7,000 to 8,000.

[0084] The difference between the M n of the second fluoropolymer (B) and the M n of the first fluoropolymer (A) may be 500 or more, typically 1,000 or more, and particularly typically 1,500 or more in light of the low glossiness of a film formed from the composition. Moreover, the upper limit of the difference is 10,000 or less, for example. The difference between the M n of the second fluoropolymer (B) and the M n of the first fluoropolymer (A) may provide the composition with a viscosity and/or flowability during curing that provides the resulting film with excellent surface smoothness, low glossiness, impact resistance, water resistance and/or salt water resistance.

[0085] The hydroxyl number of the first fluoropolymer (A) is less than the hydroxyl number of the second fluoropolymer (B). Said differently, the hydroxyl number of the second fluoropolymer (B) is greater than the hydroxyl number of the first fluoropolymer (A). The hydroxyl number of the second fluoropolymer (B) may be 80 mg KOH/g or more, typically 100 to 200 mg KOH/g, particularly typically 105 to 150 mg KOH/g, and particularly 110 to 130 mg KOH/g. In some embodiments, the hydroxyl number of the second fluoropolymer (B) typically ranges from 100 to 130 mgKOH/g, or 105 to 125, particularly typically ranging from 110 to 120, and more particularly typically ranging from 116 to 122.

[0086] The second fluoropolymer (B) may have an acid value. The acid value may be 50 mg KOH/g or less, typically 1 mg KOH/g or less, and particularly typically 0.1 mg KOH/g or less.

[0087] The difference between the hydroxyl number of the second fluoropolymer (B) and the hydroxyl number of the first fluoropolymer (A) may be 10 mg KOH/g or more, typically 20 mg KOH/g or more, and particularly typically 50 mg KOH/g or more in light of the low glossiness of a film formed from the composition. Moreover, the upper limit of the difference is 300 mg KOH/g or less, for example. The difference between the hydroxyl number of the first fluoropolymer (A) and the hydroxyl number of the second fluoropolymer (B) may provide the composition with cross-linking properties during curing that provide the resulting film with excellent ultra-violet stability, durability, abrasion resistance, and weather resistance. Additionally or alternatively, the hydroxyl number of the first fluoropolymer (A) being less than the hydroxyl number of the second fluoropolymer (B) may provide the resulting film after curing with excellent crack resistance under temperature cycles between a high temperature of at least l00°C and a low temperature of l0°C.

[0088] The first fluoropolymer (A) and the second fluoropolymer (B) may be produced by a known method. The method for producing the first fluoropolymer (A) and the second fluoropolymer (B) includes a method of copolymerizing each monomer in the presence of a solvent and a radical polymerization initiator, and specific examples include solution polymerization, emulsion polymerization, and suspension polymerization. The reaction temperature, reaction pressure, and reaction time in production may be adjusted appropriately.

[0089] The composition includes polyester (C). Polyester (C) may be a polymer having no fluorine atom being incompatible with the first fluoropolymer (A) or the second fluoropolymer (B). Polyester (C) is, for example, a polymer including a structure in which a polyvalent carboxylic acid based unit and a polyhydric alcohol based unit are linked by an ester bond. Polyester (C) may include a hydroxycarboxylic acid based unit and the like as a unit other than a polyvalent carboxylic acid based unit and a polyhydric alcohol based unit.

[0090] The polyvalent carboxylic acid may be aromatic carboxylic acid of the carbon number 8 to 15. Specific examples of the polyvalent carboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, trimellitic acid, pyromellitic acid, and phthalic anhydride. As polyvalent carboxylic acid, isophthalic acid is typical in light of the weather resistance. Two or more types of polyvalent carboxylic acid may be used in combination.

[0091] The polyhydric alcohol may be a polyhydric alcohol of the carbon number 2 to 10. Specific examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol,

1.2-propanediol, 1, 3-propanediol, l,3-butanediol, l,4-butanediol, l,5-pentanediol, neopentyl glycol, spiroglycol, l,l0-decanediol, l,4-cyclohexanedimethanol, trimethylole thane, trimethylolpropane, glycerin, and pentaerythritol. As the polyhydric alcohol, neopentyl glycol,

1.2-pentanediol, l,5-pentanediol, and trimethylolpropane are typical, and neopentyl glycol and trimethylolpropane are particularly typical. Two or more types of polyhydric alcohol may be used in combination.

[0092] Polyester (C) may be a linear polyester resin in light of the impact resistance of a film formed from the composition.

[0093] The softening temperature of polyester (C) may be 100 to l50°C, and typically 105 to l30°C in light of the dispersibility of the composition when it is made into a paint.

[0094] The Tg of polyester (C) may be 35 to l50°C, and typically 50 to l00°C in light of the blocking resistance of the composition. [0095] The M n of polyester (C) may be 5,000 or less in light of the impact resistance of a film formed from the composition. The M w of polyester (C) when polyester (C) is a polyester resin may be 2,000 to 20,000, and typically 4,000 to 10,000 in light of the impact resistance of a film formed from the composition.

[0096] In several embodiments, polyester (C) may have a hydroxyl functional group. When polyester (C) does not have a hydroxyl number, the hydroxyl number of the first fluoropolymer

(A) is 0 mg KOH/g. When polyester (C) has a hydroxyl functional group, the hydroxyl number of polyester (C) may be 1 to 500 mg KOH/g, typically 5 to 400 mg KOH/g, and particularly typically 20 to 350 mg KOH/g.

[0097] Between the hydroxyl number of polyester (C) and the hydroxyl number of the second fluoropolymer (B), the hydroxyl number of polyester (C) may be greater than the hydroxyl number of the second fluoropolymer (B). Alternatively, the hydroxyl number of the second fluoropolymer

(B) may be greater than the hydroxyl number of polyester (C).

[0098] In addition, between the hydroxyl number of polyester (C) and the hydroxyl number of the first fluoropolymer (A), the hydroxyl number of polyester (C) may be greater than the hydroxyl number of the first fluoropolymer (A). Alternatively, the hydroxyl number of the first fluoropolymer (A) may be greater than the hydroxyl number of polyester (C)

[0099] In light of the chemical resistance of a film formed from the composition, the difference between the hydroxyl number of polyester (C) and the hydroxyl number of the second fluoropolymer (B) may be 1 mg KOH/g or more, typically 10 mg KOH/g or more, and particularly typcially 15 mg KOH/g or more. In addition, the difference is 300 mgKOH/g or less, for example. Among them, when the hydroxyl number of the first fluoropolymer (A) is greater than the hydroxyl number of polyester (C), the difference between the hydroxyl number of polyester (C) and the hydroxyl number of the second fluoropolymer (B) may be 30 to 200 mg KOH/g and typically 60 to 150 mg KOH/g. As described above, it is believed that when the difference between the hydroxyl number of polyester (C) and the hydroxyl number of the second fluoropolymer (B) is within an appropriate range, the first and second fluoropolymers (A) and (B) together and polyester (C) appropriately repel each other, and the first and second fluoropolymers (A) and (B) together having an excellent chemical resistance are more likely to be localized on the surface of a film formed from the composition, and the chemical resistance of the film formed from the composition is improved.

[00100] Polyester (C) may have a carboxy group. When polyester (C) has a carboxy group, the acid value of polyester (C) may be 0.1 to 80 mg KOH/g, typically 0.2 to 50 mg KOH/g, and particularly typically 0.3 to 40 mg KOH/g.

[00101] When polyester (C) has a hydroxyl functional group, the acid value of polyester (C) is typically 5 mg KOH/g or less. Polyester (C) may have both an acid value and a hydroxyl number.

[00102] Specific examples of polyester (C) include“CRYLCOAT 4890-0” (hydroxyl value

(hydroxyl number): 30 mg KOH/g),“CRYLCOAT 2828” (hydroxyl value (hydroxyl number): 100 mg KOH/g), and“CRYLCOAT 2814” (hydroxyl value (hydroxyl number): 300 mg KOH/g) manufactured by Daicel Allnex,“U-pica Coat GV-740” (hydroxyl value (hydroxyl number): 50 mg KOH/g),“U-pica Coat GV-150” (hydroxyl value (hydroxyl number): 34.0 mg KOH/g),“U- pica Coat GV-110” (hydroxyl value (hydroxyl number): 49 mg KOH/g), and “BIOMUP” (hydroxyl value (hydroxyl number): 32 mg KOH/g) manufactured by Japan U-pica,“Uralac 1680” (hydroxyl value (hydroxyl number): 30 mg KOH/g) manufactured by DSM, and“FINEDIC M- 8010” (hydroxyl value (hydroxyl number): 24 mg KOH)/g),“FINEDIC M-8021” (hydroxyl value (hydroxyl number): 30 mg KOH/g), and“FINEDIC M-8023” (hydroxyl value (hydroxyl number): 40 mg KOH/g) manufactured by DIC. Two or more types of polyester (C) may be used in combination.

[00103] In the composition, in light of reducing pinholes of a film formed from the composition and the chemical resistance and the weather resistance of the film formed from the composition, the total number of hydroxyl functional groups included in polyester (C) is typically greater than the total number of hydroxyl functional groups included in the first fluoropolymer (A) and the total number of hydroxyl functional groups included in the second fluoropolymer (B).

[00104] The composition typically satisfies the following formula 1.

[00105] Formula 1 : (Hydroxyl number of polyester (C) x Content mass of polyester (C)) > ((Hydroxyl number of the first fluoropolymer (A) x Content mass of the first fluoropolymer (A) + Hydroxyl number of the second fluoropolymer (B) x Content mass of the second fluoropolymer (B)).

[00106] In the composition, the value of (Hydroxyl number of polyester (C) x Content mass of polyester (C)) / ((Hydroxyl number of the first fluoropolymer (A) x Content mass of the first fluoropolymer (A) + Hydroxyl number of the second fluoropolymer (B) x Content mass of the second fluoropolymer (B)) is typically more than 1.0 and no more than 3.0, and particularly typically 1.1 to 2.0.

[00107] Without being bound to any particular theory, it is believed when the composition satisfies such a relationship and when the composition is melt-cured to form a film, since the curing rate of the first fluoropolymer (A) and the second fluoropolymer (B) together which tends to be unevenly distributed to the surface side tends to be slow relative to the curing rate of polyester (C) which tends to be unevenly distributed to the base material side, preferable defoaming is achieved when the film is formed. Also, pinholes are less likely to be generated on the surface of the film and the appearance of the film is improved. The appearance of the film is alternatively, or in addition, improved by differential curing, described further below. Furthermore, the chemical resistance and weather resistance of the film are improved by reducing the pinholes.

[00108] The content of the first fluoropolymer (A) in the composition may be 1 to 40% by mass, typically 5 to 30% by mass, and particularly typically 10 to 25% by mass relative to the total mass of the composition. The content of the second fluoropolymer (B) in the composition may be 0.5 to 40% by mass, typically 0.7 to 30% by mass, and particularly typically 1.0 to 20% by mass relative to the total mass of the composition. The content of polyester (C) in the composition may be 5 to 65% by mass, typically 6 to 60% by mass, and particularly typically 10 to 50% by mass relative to the total mass of the composition. The total content of the first fluoropolymer (A) and the second fluoropolymer (B) in the composition may be 5 to 50% by mass, typically 8 to 40% by mass, and particularly typically 10 to 35% by mass relative to the total mass of the composition. The total content of the first fluoropolymer (A), the second fluoropolymer (B), and polyester (C) in the composition may be 20 to 90% by mass, and typically 25 to 80% by mass, and particularly typically 40 to 70% by mass relative to the total mass of the composition.

[00109] The content of the first fluoropolymer (A) in the composition may be 1 to 60% by mass, typically 10 to 50% by mass, and particularly typically 20 to 50% by mass relative to the total mass of the first fluoropolymer (A), the second fluoropolymer (B), and polyester (C). Hereinafter, the first fluoropolymer (A), the second fluoropolymer (B), and polyester (C) are collectively referred to as resin components. The content of the second fluoropolymer (B) in the composition may be 1 to 60% by mass, typically 1.5 to 50% by mass, and particularly typically 2.0 to 20% by mass relative to the total mass of the resin components. The content of polyester (C) in the composition may be 10 to 90% by mass, typically 15 to 85% by mass, and particularly typically 20 to 80% by mass relative to the total mass of the resin components. The total content of the first fluoropolymer (A) and the second fluoropolymer (B) together in the composition may be 10 to 80% by mass, typically 15 to 70% by mass, and particularly typically 20 to 60% by mass relative to the total mass of the resin components.

[00110] The mass ratio of the total content of the first fluoropolymer (A) and the second fluoropolymer (B) together to the content of polyester (C) (the total content of the first fluoropolymer (A) and the second fluoropolymer (B) together / the content of polyester (C)) in the composition may be 0.1 to 10.0, typically 0.5 to 5.0, and particularly typically 0.7 to 4.0. The mass ratio of the content of the first fluoropolymer (A) to the content of the second fluoropolymer (B) (the content of the first fluoropolymer (A) / the content of the second fluoropolymer (B)) in the composition is 0.01 to 99, typically 0.25 to 99, more typically 1 to 49, and particularly typically 2 to 32.

[00111] The composition includes curing agent (D). The curing agent (D) is also commonly referred to as a cross-linking agent (D) or cross-linker (D). Curing agent (D) is reactive with the hydroxyl functional groups of the first and second fluoropolymers. When polyester (C) includes hydroxyl functional groups, the curing agent (D) is also reactive with the hydroxyl functional groups of polyester (C). For example, curing agent (D) has two or more groups capable of reacting with the hydroxyl functional groups of the first fluoropolymer (A), the second fluoropolymer (B), and polyester (C) (the resin components) in one molecule and is able to crosslink the resin components. Curing agent (D) typically has 2 to 30 groups capable of reacting with the hydroxyl functional groups. Typically, curing agent (D) may be a compound having two or more isocyanate groups or blocked isocyanate groups in one molecule that are reactive with at least one hydroxyl functional group of at least one of the first and second fluoropolymers (A) and (B) and polyester (C). Curing agent (D) is able to crosslink the resin components that having a hydroxyl functional group.

[00112] Examples of curing agent (D) having two or more isocyanate groups in one molecule include alicyclic polyisocyanates such as isophorone diisocyanate and dicyclohexylmethane diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, and modified products thereof. Alternatively or additionally, the blocked isocyanate curing agent is typically one produced by reacting a polyisocyanate obtained by reacting an aliphatic, aromatic or araliphatic diisocyanate and a low molecular compound having active hydrogen, with a blocking agent, for masking. Specific examples of curing agent (D) having two or more blocked isocyanate groups in one molecule include diisocyanate (tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4’-methylenebis (cyclohexyl isocyanate), methylcyclohexane diisocyanate, bis (isocyanate methyl) cyclohexane, isophorone diisocyanate, dimer acid diisocyanate, lysine diisocyanate, and the like) and compounds obtained by reacting with a blocking agent. Moreover, the low molecular compound having active hydrogen may, for example, be water, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, ethanolamine, diethanolamine, hexamethylenediamine, isocyanurate, uretdione, a low molecular weight polyester containing hydroxy groups, polycaprolactone, etc. Specific examples of the blocking agent include alcohol (methanol, ethanol, benzyl alcohol, etc.), phenol (phenol, cresol, etc.), active methylene, amine, imine, acid amide, lactam (caprolactam, butyrolactam, etc.), oxime (cyclohexanone, oxime, methyl ethyl ketoxime, etc.), pyrazole, imidazole, imidazoline, pyrimidine, and guanidine. [00113] For example, the curing agent (D) may be a compound having at least one isocyanate group that is reactive with at least one hydroxyl functional group of the at least one hydroxyvinyl ether based unit, such as 4-hydroxybutyl vinyl ether (HBVE) compound, in at least one, or both, of the first and second fluoropolymers (A) and (B). In various embodiments, the NCO:OH molar ratio of the composition is from 1: 1 to 1.5: 1, or any value or range of values including those values or between those values. In various embodiments, where the curing agent (D) does not include isocyanate groups, curing agent (D) includes reactive groups wherein a molar ratio of said reactive groups to said hydroxyl functional groups is 1 : 1 to 1.5: 1.

[00114] In various embodiments, reactive groups of the curing agent (D) are ones which are likely to react with the hydroxyl groups of at least one of the first and second fluoropolymers (A) and (B) and polyester (C) at room temperature. In other embodiments, these reactive groups do not react at room temperature and instead react when the powder coating composition is heated and melted. For example, the curing agent (D) may be a blocked isocyanate curing agent. In the blocked isocyanate curing agent, blocked isocyanate groups become isocyanate groups, when the powder coating composition is heated and melted to separate the blocking agent, and the isocyanate groups thus formed, will serve as reactive groups. One such blocked isocyanate curing agent that may be used is Vestagon B1530 which is a e-caprolactam blocked polyisocyanate commercially available from Evonik Industries and which has an NCO content of 14.8 to 15.7, deblocking temperature of about 180 °C, functionality of 2.7, NCO equivalent of about 275 g/Eq, and glass transition temperature (T g ) of 41-53 °C.

[00115] When any one or more types of the resin components have an acid value and the like, curing agent (D) having two or more groups capable of reacting with a carboxy group in one molecule (an epoxy group, a carbodiimide group, an oxazoline group, a b-hydroxyalkylamide group, and the like) may be used.

[00116] Alternatively, the curing agent (D) may be selected from the group consisting of a compound having at least one carboxyl group, a melamine resin, and a compound having an epoxy group. In various embodiments, a beta-hydroxyalkylamine curing agent or an epoxy curing agent may be used. The beta-hydroxyalkylamine curing agent may, for example, be a melamine resin, a guanamine resin, a sulfonamide resin, an urea resin, an aniline resin, etc., wherein a hydroxymethyl group or an alkoxymethyl group is bonded to the nitrogen atom of an amino group or an amide group. The epoxy curing agent may, for example, be a triglycidyl isocyanurate. Two or more types of curing agent (D) may be used in combination.

[00117] The content of curing agent (D) in the composition is typically 1 to 80% by mass and more typically 15 to 75% by mass relative to the total content of the first fluoropolymer (A), the second fluoropolymer (B), and polyester (C) (the resin components) in the composition.

[00118] The composition may comprise additional components and/or additives. In various embodiments, the composition may include one or more of the additives listed below. The additives include, but are not limited to, a fluoropolymer other than the first fluoropolymer (A) and the second fluoropolymer (B), a non-fluorine resin other than the polyester ((meth)acrylic resin, urethane resin, and the like), a pigment, a catalyst (a curing catalyst and the like), a filler, a light stabilizer, an ultra-violet absorber, a matting agent (ultrafine synthetic silica, etc.), a surface conditioner (e.g. to improve the surface smoothness of a film formed from the composition), a degassing agent, a fluidizer, a heat stabilizer, an antistatic agent, a rust inhibitor, a silane coupling agent, a low pollution treatment agent, a plasticizer, an adhesive, a leveling agent, a wax, a surfactant (nonionic surfactant, cationic surfactant or anionic surfactant), a thickener, a dispersing agent, an antifouling agent, etc., and combinations thereof.

[00119] The composition may include at least one, or two or more, pigments. The pigments are not particularly limited and may be any known in the art. Specific examples of the pigment in the composition include an organic pigment and an inorganic pigment. Examples of pigments include, but are not limited to, phthalocyanine blue, phthalocyanine green, hansa yellow, azo green, red oxide, carbon black, iron oxide, quinacridone, isoindolinone, benzoimidazolone, dioxazine, yellow ochre, and umber.

[00120] Typically, the composition includes an inorganic pigment and particularly typically, the inorganic pigment is titanium dioxide. The titanium dioxide is not particularly limited and may be any known in the art including both surface-treated and untreated titanium dioxide. For example, the titanium dioxide may be of any particle size and have an average particle size that is any type of distribution known in the art. The titanium dioxide may be rutile titanium dioxide. Rutile titanium dioxide is an efficient ultra-violet radiation protector in polymer coating compositions and films formed thereof and strongly absorbs radiation below 380 nm. The titanium dioxide may be surface-treated with one or more treatments of one or more metals or metal oxides, e.g. alumina, silica, amorphous silica, aluminum oxide, silicon oxide, zirconia, selenium, an organic component (polyol), etc. which may be used in various embodiments. The surface treatment may partly prevent a photocatalytic reaction from proceeding in full or may reduce the rate at which the photocatalytic reaction proceeds. Titanium dioxide which is surface-treated is typical and titanium dioxide which is surface-treated as described is particularly typical. When the titanium dioxide is surface-treated, the purity of the titanium dioxide is in a range from 85 to 95% by mass, more typically in a range from 87 to 93% by mass. When the titanium oxide is surface-treated, the titanium oxide content may be adjusted to 70 to 95% by mass by surface treatment, and particularly typically adjusted to 83 to 90% by mass. When the titanium dioxide content is at least above 85% by mass, the film tends to be excellent in whiteness. Commercial products of titanium oxide may, for example, be PFC105, or CR-95, commercially available from Ishihara Sangyo Kaisha, Ltd. or Nagase & Co., Ltd. under the trade name Tipaque™; or Ti-Pure or Ti-Pure Select, commercially available from The Chemours Company.

[00121] In various embodiments, one or more of the following titanium dioxides can be used: Ti-Pure™ R-101; Ti-Pure™ R-103; Ti-Pure™ R-104; Ti-Pure™ R-105; Ti-Pure™ R-350; Ti-Pure™ R-6200; Ti-Pure™ Select TS-6200; Ti-Pure™ Select TS-6300; Ti-Pure™ R-706; Ti- Pure™ R-741; Ti-Pure™ R-746; Ti-Pure™ R-796+; Ti-Pure™ R-900; Ti-Pure™ R-902+; Ti- Pure™ R-931; Ti-Pure™ R-942P; Ti-Pure™ R-960 for Plastics; Ti-Pure™ R-960 for Coatings; Biasill™; Staurolite Sand; Starblast™; Starblast™ Ultra; Staurolite; Zircon Sands; Zircore™; Kyasill™; and combinations thereof, all commercially available from The Chemours Company; and R-820; R-830; R-930; R-980; R-953; R-630; UT771; PF-690; PF-691; PFC105; CR-50; CR- 57; CR-Super70; CR-80; CR-90; CR-90-2; CR-93; CR-95; CR-97; CR-63; and combinations thereof, all commercially available from Ishihara Sangyo Kaisha, Ltd. or Nagase & Co., Ltd. under the trade name Tipaque™.

[00122] An exemplary titanium dioxide is rutile titanium dioxide, is produced by a chloride process and is surface-treated with silica, zirconia, alumina, and organic compounds including polyol. This exemplary titanium dioxide, including surface treatment, has a particle size of about 0.28 pm and oil absorption of about 22 grams per 100 grams. The titanium dioxide content is at least 87% by mass in this exemplary titanium dioxide including surface treatment. A known fluoropolymer paint including this exemplary titanium dioxide, including surface treatment, and having a pigment to binder ratio of 0.6 to 1, exhibits gloss retention at 57% (20° -20°) and is acceptably durable. Durability is interpreted by gloss retention (expressed as a percentage). For example, in a super accelerated exposure test, such as a known Xenon Arc exposure under spray of hydrogen peroxide (H2O2) solution, the known fluoropolymer paint maintains 100% gloss retention at 60° for about 70 hours of exposure time and gloss retention at 60° remains above 60% at about 100 hours of exposure time. At about 110 hours of exposure time, gloss retention at 60° is about 50%.

[00123] Another exemplary titanium dioxide is rutile titanium dioxide, is produced by a chloride process, is surface-treated with silica, alumina, and surface-treated twice with organic compounds. The organic compounds in each surface treatment each have a low number average molecular weight (M n ) and each include a high amount of function groups, such as acid, ester, and/or alcohol functional groups. Examples of the organic compounds include, but are not limited to, polyols, amines and amine salts. The titanium dioxide content is at least 93% by mass in this exemplary titanium dioxide including surface treatment. The amount of alumina as a total from both surface treatments is about 3.6% by mass and the amount of silica as a total from both surface treatments is about 3.3% by mass. A known polyester powder coating including this exemplary titanium dioxide, including surface treatment, maintains at least 80% gloss retention at 60° for three years of exposure to the outside environment, including moisture, oxygen and ultra-violet radiation, in Florida. The known polyester powder coating including this exemplary titanium dioxide, including surface treatment, is acceptably durable.

[00124] Another exemplary titanium dioxide is rutile titanium dioxide, is produced by a chloride process and is surface-treated with amorphous silica and alumina, and without organic compounds. This exemplary titanium dioxide, including surface treatment, has a median particle size of about 0.50 mih and oil absorption of about 18.7 grams per 100 grams. The titanium dioxide content is at least 89% by mass, more typically 90 %by mass, in this exemplary titanium dioxide including surface treatment. The amount of alumina in the surface treatment is no more than 3.5 weight percent, more typically about 3.3 %by mass. The amount of amorphous silica in the surface treatment is no more than 6.5 %by mass, more typically about 5.5 % by mass. A known polypropylene coating including this exemplary titanium dioxide, including surface treatment, maintains gloss retention at about 90% for about 450 hours of Xenon Arc exposure and gloss retention remains above 50% for about 750 hours of Xenon Arc exposure. A known polyvinyl chloride (PVC) coating including this exemplary titanium dioxide, including surface treatment, maintains gloss at about 20% at 60° for 24 months of exposure to the outside environment, including moisture, oxygen and ultra-violet radiation, in southern Florida. The known polypropylene and PVC coatings, each including this exemplary titanium dioxide including surface treatment, are acceptably durable.

[00125] Untreated titanium dioxide may allow or enable a photocatalytic degradation reaction to proceed in regions where the sun shines more often, particularly in hot and humid regions. The photocatalytic reaction may be promoted by moisture, oxygen and ultra-violet radiation. For example, the moisture, oxygen and ultra-violet radiation causes the titanium dioxide to release an oxygen free radical (O ) which then may attack carbon-carbon bonds in polymer components in the film. When exposed to water, oxygen and ultra-violet radiation, the rutile titanium dioxide, which is not surface-treated, may act as a photocatalytic agent. This can cause deterioration of a film on a substrate or base material, such as for architectural applications, for example on a building material (gate, fence, siding material for a house, curtain wall, roof, etc.). In instances where this may be more of a concern, the titanium dioxide may be surface-treated, as described.

[00126] The surface treatment prevents the photocatalytic degradation reaction from occurring at the same rate as the photocatalytic degradation reaction would occur without the surface treatment of titanium dioxide. The surface treatment may minimize the ability of the moisture, oxygen and/or ultra-violet radiation to reach polymer components in films.

[00127] Further, the presence of surface-treated titanium dioxide in the film which results from curing the composition is greatly reduced at the surface of the film, for example, the surface of the film facing the ultra-violet radiation. Because the titanium dioxide may be surface-treated and because the surface-treated titanium dioxide in the film may be minimally present at the surface of the film, prevention of the surface-treated titanium dioxide from being exposed to moisture, oxygen and ultra-violet radiation, may be maximized, thereby preventing the titanium dioxide from allowing or enabling the photocatalytic reaction which causes deterioration of the film.

[00128] In various embodiments, when the composition includes a pigment, such as is titanium dioxide, not including the mass of surface treatment, the content thereof relative to the total 100 parts by mass of the total content of the resin components is typically 10 parts by mass or more, more typically 15 to 80 parts by mass, and particularly typically 20 to 70 parts by mass. In some embodiments, when the composition includes a pigment, such as titanium oxide, the content thereof relative to the total mass of the composition is typically 5 to 50% by mass and particularly typically 10 to 40% by mass. Moreover, all combinations of values including and between those set forth above are hereby expressly contemplated in various non-limiting embodiments. The amount of the titanium dioxide utilized in the composition may be related to glossiness and color retention and corrosion resistance in the film formed from the composition. When the composition includes titanium dioxide, a film formed from the composition does not have the titanium dioxide largely present at the surface of the films. Less orange peel is exhibited. Also, photocatalytic reactions and accelerated photocatalytic reactions do not occur at the surface of the films, and/or the frequency of the photocatalytic reactions is reduced.

[00129] For example, as additives, the composition may comprise a ultra-violet absorber. Specific examples of the ultra-violet absorber include an organic ultra-violet absorber and an inorganic ultra-violet absorber. The ultra-violet absorber may be lipophilic or hydrophilic. A single ultra-violet absorber may be used or more than one may be used. The ultra-violet absorber may be an organic ultraviolet absorber in light of the fact that it is considered that the ultra-violet absorber tends to easily protect the polyester in a film formed from the composition by being unevenly distributed on the surface side of the film. The organic ultra-violet absorbers may, for example, be salicylic acid esters, benzotriazoles, benzophenones, cyanoacrylates, and triazines (particularly, hydroxyphenyl triazines). As the organic ultra-violet absorber, a compound having a molecular weight of from 200 to 1,000 is typical. When the molecular weight is at least 200, it is less likely to volatilize in the melting and curing process of the powder coating composition. As the organic ultra-violet absorber, a compound having a melting point of from 50 to l50°C is typical. As the organic ultra-violet absorber, a compound having a volatilization temperature of from 180 to 400°C is typical, and a compound having a volatilization temperature of from 220 to 350°C is particularly preferred. Non-limiting commercial examples of the ultra-violet absorber include BASF trade names“Tinuvin 326,”“Tinuvin 405,”“Tinuvin 460,”“Tinuvin 900,” and

“Tinuvin 928” and Clariant trade names“Sanduvor VSU powder” and“Hastavin PR-25 Gran.” [00130] The inorganic ultra-violet absorber may, for example, be a filler-type inorganic ultra-violet absorber including ultra-violet absorbing oxides (such as zinc oxide, cerium oxide, etc.)· As the inorganic ultra-violet absorber, composite particles of titanium oxide and zinc oxide, composite particles of titanium oxide and cerium oxide, composite particles of zinc oxide and cerium oxide, composite particles of titanium oxide, zinc oxide and cerium oxide, etc. are typical.

[00131] When the composition includes an ultra-violet absorber, the content thereof relative to the total mass of the composition may be 0.01 to 30% by mass and particularly typically 1 to 10% by mass. The ratio of the mass of the ultraviolet absorber to the total mass of the resin components (the mass of the ultraviolet absorber / the total mass of the first fluoropolymer (A), the second fluoropolymer (B), and polyester (C)) is typically 0.01 to 1 and particularly typically 0.05 to 0.5. When a composition containing an ultra-violet absorber is used in the range, it is believed that the ultraviolet absorber tends to be unevenly distributed on the surface side of a film formed from the composition, and the film has an excellent weather resistance.

[00132] For example, as additives, the composition may comprise a light stabilizer. The light stabilizer may be hindered amine (HALs) in light of it tending to be unevenly distributed in the region where polyester (C) in a film formed from the composition is unevenly distributed. The light stabilizer suppresses the deterioration of polyester (C) and reduces deterioration of the film. The hindered- amine light stabilizer (HALs) are typically benzotriazoles or triazines. Non-limiting commercial examples of the light stabilizer include BASF trade names“Tinuvin 111 DL,” “Tinuvin 144,” and“Tinuvin 152,”“Sanduvor 3051 powder” manufactured by Clariant, and Clariant trade names“Sanduvor 3070 powder,” and“VP Sanduvor PR-31.” [00133] When the composition includes a light stabilizer, the content thereof relative to the total mass of the composition may be 0.01 to 30% by mass, more typically 0.05 to 20% by mass, and particularly typically 1 to 5% by mass.

[00134] The composition may or may not include a solvent (water, organic solvent, and the like), and it typically does not include a solvent. When the composition includes a solvent, it is typically less than 1% by mass relative to the total mass of the composition.

[00135] When the composition includes a filler, the filler may include one or more fillers, which are not particularly limited and may be known in the art. Examples of the fillers include, but are not limited to, resin beads and the like, calcium carbonate, calcium metasilicate, barium sulfate or baryte, talc, mica, clays such as kaolin, zinc oxide and silica.

[00136] Further additives may alternatively or additionally be incorporated into the composition. These additives include, but are not limited to, matting agents (e.g. ultrafine synthetic silica, etc.), surfactants (e.g. nonionic surfactants, cationic surfactants or anionic surfactants), leveling agents, surface conditioning agents (e.g. to improve the surface smoothness of the film), de-gassing agents, fillers, heat stabilizers, thickeners, dispersing agents, antistatic agents, rust inhibitors, silane coupling agents, antifouling agents, low pollution treatment agents, catalysts, flow agents, and combinations thereof. For example, flow agents for improving degassing of powder coatings on porous substrates or base materials may be included in the composition. Non-limiting commercial examples of flow agents include CERAFFOUR 961. Flow agents may be incorporated into the composition in an amount of from 1 to 2% by mass of the composition, typically 1.3 to 1.8% by mass, more typically 1.4 or 1.5 to 1.6 or 1.7 or 1.8% by mass. [00137] Additionally or alternatively, surface conditioners for improving leveling and preventing cratering for powder coating or pigmented powder coatings may be added. Non limiting commercial examples include BYK-360 P available from BYK Additives & Instruments and Benzoflex 352 from Eastman Chemical Co., Ltd. Surface conditioners may be incorporated into the composition in an amount of from 1 to 2% by mass of the composition, typically 1.3 to 1.8% by mass, more typically 1.4 or 1.5 to 1.6 or 1.7 or 1.8 % by mass.

[00138] De-gassing agents may additionally or alternatively be incorporated into the composition. Non-limiting commercial examples include Benzoin. De-gassing agents may be incorporated into the composition in an amount of from 0.1 to 0.5% by mass of the composition, typically 0.2 to 0.4% by mass, more typically 0.3% by mass.

[00139] Catalysts may additionally or alternatively be incorporated into the composition. Non-limiting commercial examples include dibutyltin dilaurate (DBTDL) available from TRIGON Chemie GmbH. A catalyst solution having one part catalyst to 100 parts solvent may be incorporated into the composition in an amount of from 0.1 to 0.5% by mass of the composition, typically 0.1 to 0.3% by mass, more typically 0.2% by mass.

[00140] It is also contemplated that the composition and/or film formed from the composition may include less than 5, 4, 3, 2, 1, 0.5, 0.1, 0.05, or 0.01, % by mass of any one or more of the additives set forth throughout this disclosure, based on a total weight of the composition and/or film, respectively. It is also contemplated that the composition and/or film may be free of one or more of any one or more of the additives set forth throughout this disclosure. Moreover, all combinations of values including and between those set forth above are hereby expressly contemplated in various non-limiting embodiments. [00141] The pellet flow measured according to ASTM D 4242-02 of the composition is typically 30 to 150 mm, more typically 31 to 45 mm, and particularly typically 32 to 45 mm. Suitable values for pellet flow also range from 40 to 150 mm, typically 45 to 140 mm, and more typically 60 to 135 mm. Pellet flow is a measure of determining performance of film(s) formed by curing the composition(s). Pellet flow test interprets the effect of the combination of melt viscosity and curing dynamics.

[00142] The composition can be produced by mixing the first fluoropolymer (A), the second fluoropolymer (B), polyester (C), curing agent (D), and, as necessary, the additive(s). The first fluoropolymer (A), the second fluoropolymer (B), polyester (C), curing agent (D), the additive(s), and the like to be mixed may each be in the form of an independent powder or pellet.

[00143] As one embodiment of the method for producing the composition, a method in which powder A containing the first fluoropolymer (A), powder B containing the second fluoropolymer (B), and powder C containing polyester (C) are mixed to obtain the composition is included. This method is also referred to as dry blending, and it is a method in which melt mixing is not carried out at the time of mixing. At least one of the powder A, the powder B, and the powder C includes curing agent (D).

[00144] In addition, as one embodiment of the method for producing the composition, a method in which the first fluoropolymer (A), the second fluoropolymer (B), polyester (C), curing agent (D), and, as necessary, the additive are melt-kneaded, cooled, and then pulverized to obtain the composition is included. The first fluoropolymer (A), the second fluoropolymer (B), and polyester (C) are contained in the same particle. The composition may be produced by melt- kneading. The temperature for the melt-kneading is typically 80 to l30°C. The pulverization may be carried out using a pulverizer such as a pin mill, a hammer mill, or a jet mill. After carrying out the pulverization, it is typical to classify the pulverized product to make the particle diameter of the obtained composition uniform. The average particle diameter of the composition is typically 1 to 100 pm, more typically 10 to 80 pm, and particularly typically 25 to 50 pm.

[00145] A film formed from the composition is formed by applying the composition on a base material. In addition, the coated article has a base material and the film formed from the composition put on the base material. The coated article may also commonly be referred to as a painted product. Specific examples of the material of the base material include inorganic substance, organic substance, and organic-inorganic composite. Specific examples of the inorganic substance include concrete, natural stone, glass, metal (iron, stainless steel, aluminum, iron, magnesium, copper, brass, titanium, and the like). Specific examples of the organic substance include plastic, rubber, adhesive, and wood. Specific examples of the organic-inorganic composite include fiber reinforced plastic, resin reinforced concrete, and fiber reinforced concrete. In addition, the base material may be subjected to known surface treatment (such as chemical conversion treatment). In addition, a resin layer or the like formed by applying a primer and the like (a polyester resin layer, an acrylic resin layer, a silicone resin layer, and the like) may be provided in advance on the surface of the base material. Among the above, metal is typical as the material of the base material, and aluminum is particularly typical. The base material made of aluminum is excellent in corrosion resistance, is lightweight, and is suitable for a building material such as an exterior member. The shape, size, and the like of the base material are not particularly limited. Specific examples of the base material include a composite panel, a panel for a curtain wall, a frame for a curtain wall, an exterior member for construction such as a window frame, a tire wheel, a wiper blade, an automobile member such as an automobile exterior, a construction machine, a frame for a motorcycle. Other examples include a building material (window, door, storefront, louvres, sunshade, ornamental materials, gate, fence, siding material for a house, curtain wall, roof, etc.), a traffic signal, a telephone pole, a road sign pole, a bridge, a railing, an automobile body or parts (bumper, wiper blade, etc.), a household appliance (outdoor unit of air conditioner, exterior of water heater, etc.), a blade for wind power generation, a solar cell back sheet, a back surface of a heat collection mirror for solar power generation, a NAS battery exterior, etc.

[00146] The film thickness of a film formed from the composition may be 20 to 1 ,000 pm, and particularly typically 20 to 500 pm. For an application such as a member for a tall building such as an aluminum curtain wall, 20 to 90 pm is typical. For an application requiring high weather resistance such as an outdoor unit of an air conditioner installed along the coast, a pole of traffic lights, a sign, and the like, 100 to 200 pm is typical.

[00147] When the composition contains a pigment, such as titanium oxide, a surface fluorine to titanium (F/Ti) normalized atomic ratio may be determined. This value (F/Ti) is the number of fluorine atoms to the number of titanium atoms on the surface of a film formed from the composition and is determined by analyzing the film using SEM/EDX, for example, a scanning electron microscope with an energy dispersive X-ray analyzer, TM3030 manufactured by Hitachi, Ltd. The value F/Ti is typically 5.0 or more, more typically 10.0 or more, and still more typically 15.0 or more. In addition, F/Ti is typically 40.0 or less, for example. Suitable values for F/Ti also range from 3.3 to 20, typically 4.0 to 18, and more typically 4.5 to 15. When F/Ti is in this range, the photocatalytic effect of titanium oxide on the surface of the film causes little damage to the film, and particularly when the film is used outdoors, the weather resistance of the film is excellent. Said differently, when F/Ti is in this range, the probability of photocatalytic reactions occurring is low. If the F/Ti ratio is lower than described, there is more titanium dioxide at the surface, and the probability for photocatalytic reactions to occur is higher. When the composition includes a pigment, such as surface-treated titanium dioxide, the type of surface-treated titanium dioxide may affect on the balance of glossiness, F/Ti normalized atomic ratio, and pellet flow for any particular weight ratio of first fluoropolymer (A) to second fluoropolymer (B).

[00148] The coated article may be obtained by applying the composition to the surface of a base material to form a paint layer and subjecting the resulting paint layer to heat treatment and then cooling. The paint layer may also be referred to as a coated film. The applying may also commonly be referred to as a painting. Examples of the method for forming the paint layer (coated film) include painting methods such as electrostatic painting method, electrostatic spraying method, electrostatic dipping method, flow dipping method, and spraying method, the electrostatic painting using a powder paint gun is typical. Specific examples of the powder paint gun include a corona charging type painting gun and a friction charging type painting gun. The corona charge type painting gun is a painting gun in which the composition is subjected to a corona discharge treatment and sprayed. The friction charging type painting gun is a painting gun in which the composition is subjected to a frictional electrification treatment and sprayed. The heating temperature at the time of heat treatment is typically 120 to 200°C. The heating maintenance time is usually 2 to 60 minutes. After the heat treatment, cooling to 20 to 25 °C is typical. The paint layer (coated film) is melted and cured (melt-cured) by the heat treatment and cooling to form the film formed from the composition. The cure mechanism may be any known in the art relative to the first fluoropolymer (A) and the second fluoropolymer (B), and polyester (C) when polyester (C) includes hydroxyl functional groups, and includes a cure mechanism involving cure agent (D), such as an NCO/OH (polyurethane) cure mechanism.

[00149] Alternatively, the composition may be sprayed, poured, or coated on the base material and subsequently cured on the base material to form the film on the base material by any known method in the art. A coated article may be formed which comprises the base material and the film disposed on the base material. The film may partially cure on the base material. For example, the composition may include, consist essentially of, or consist of, the cured product of (A), the cured product of (B), the cured product of (C), and (D). The curing agent (D) may be partly or fully consumed during curing. Curing, cure or cured refers to the process wherein a hard thermoset coating is formed as a result of a cross-linking reaction between the reactive groups of the components in the composition. The composition may be cured at 200°C or lower. Relative to the cured composition, the terminology“consist essentially of’ describes embodiments wherein the composition may be free of one or more fluoropolymers that is not (A) and/or (B), may be free of a polyester that is not (C), and/or may be free of an agent that is not the curing agent (D).

[00150] The film is typically a single layer but may be two layers. The film as a whole, and/or each layer, may be uncured, partially cured, or completely cured. A primer may be applied to a surface of a base material and in this instance, the composition is applied to the primer after the primer is applied to the surface of a base material. In various embodiments, the film passes the AAMA 2605 specification for architectural coatings.

[00151] The composition itself is not particularly limited in use and can be further described as a powder. The terminology“powder” typically describes that the composition is a collection of dry particles. The dry particles can have any particle size and/or particle size distribution. In various embodiments, the dry particles have an average particle size, or particle size distribution, of from 10 to 200, from 50 to 200, from 50 to 100, from 100 to 200, from 150 to 200, of less than 200, of less than 150, of less than 100, of less than 90, of less than 75, pm, etc. This particle size may be determined by any method known in the art such as by using a Malvern particle size analyzer, filters, mesh, etc. The“powder” may be in the form of flakes, or flakes may be a precursor to the“powder”. Standard coating processes known to those of ordinary skill in the art may be used to transform flakes into films. In various non-limiting embodiments, all values and ranges including and between those set forth above are hereby expressly contemplated.

[00152] The initial viscosity of the composition including (A) the first fluoropolymer, (B) the second fluoropolymer, polyester (C) and the curing agent (D) before curing/cross-linking as well as the rate at which the viscosity increases during the curing/cross-linking is believed to be a factor in providing a smooth film surface having low glossiness on the substrate. For example, the values of the number average, M n, molecular weight of fluoropolymers (A) and (B) in the composition and the glass transition temperature (T g ) of fluoropolymers (A) and (B) in the composition aid in influencing or controlling the viscosity of the composition during curing allowing the composition to flow at a desired and advantageous rate. Melting is imparted by differential curing described further below. Differential curing involves the use of fluoropolymers that have different structures. Upon incomplete molecular mixing, such as typically encountered in powder coating composition processes, differential curing result in the development of zones of varying shrinkage or varying surface tension on the substrate during curing. This yields a microscopically rough surface layer which scatters light and reduces light reflectance, thereby controlling glossiness.

[00153] Differential curing is believed to be a factor in providing a smooth film surface having low glossiness on the substrate. It is believed that a differential curing process imparts only a microscopic surface roughness to the film formed from the composition that is not visible to the human eye. Because the surface is microscopically rough, the roughness is not visible to the human eye and the film surface appears to be smooth and has low glossiness. The smooth surface is comparable to a film formed from application of a liquid coating. Glossiness of the surface layer may be measured by a gloss meter known in the art typically having a scale of 0.5 pm. The microscopic roughness may be detectable by known gloss meters. In other words, differential curing generates microscopic surface roughness on a film detectable by a gloss meter, but not by the human eye. The measuring scale of a typical gloss meter is 0.5 pm. Differential curing causes matting without the use of matting agents. With differential curing, first fluoropolymer (A) and second fluoropolymer (B) cure at different rates. The different rates of curing are due to, for example, the differences in hydroxyl number and number average molecular weight (M n ) between first fluoropolymer (A) and second fluoropolymer (B). Partly because second fluoropolymer (B) has a lower number average molecular weight (M n ) than first fluoropolymer (A), the melt viscosity of second fluoropolymer (B) is lower than first fluoropolymer (A) and it is believed that second fluoropolymer (B) is able to contact or reach the curing agent (D) before first fluoropolymer (A). Because second fluoropolymer (B) has a higher hydroxyl number than first fluoropolymer (A), second fluoropolymer (B) is more reactive than first fluoropolymer (A) with the curing agent (D) on a per mole basis. These factors contribute to the different cure rates, and thereby the differential curing, of first fluoropolymer (A) and the second fluoropolymer (B) in a composition that includes first fluoropolymer (A), the second fluoropolymer (B), polyester (C) and the curing agent (D). The composition that includes first fluoropolymer (A), the second fluoropolymer (B), polyester (C) and the curing agent (D) may be free of a matting agent, as a smooth surface and low glossiness is believed to be achieved by differential curing. Matting is achieved by differential curing without the use of a matting agent.

EXAMPLES

[00154] Examples 1 to 6 and 11 to 17 are inventive examples and Example 18 is a comparative example. The disclosure is not limited to these examples.

[00155] Name and abbreviation of ingredient: CTFE: Chlorotrifluoroethylene

CHVE: Cyclohexyl vinyl ether

HBVE: 4-hydroxybutyl vinyl ether

PE1: Polyester, Daicel Allnex Co., Ltd. trade name CRYLCOAT 4890-0 (hydroxyl value

(hydroxyl number): 30 mg

KOH/g)

PE2: Polyester, Daicel Allnex Co., Ltd. trade name CRYLCOAT 2828 (hydroxyl value (hydroxyl number): 100 mg

KOH/g)

PE3: Polyester, Daicel Allnex Co., Ltd. trade name CRYLCOAT 2814 (hydroxyl value (hydroxyl number): 300 mg

KOH/g)

Curing agent: Curing agent having two or more blocked isocyanate groups in one molecule (Vestagon B1530 which is a e-caprolactam blocked polyisocyanate commercially available from Evonik Industries)

Lluidizer: CERALLOUR 961, a commercially available additive.

Pigment 1: Titanium oxide pigment (Tipaque™ PLC105 available from Nagase & Co., Ltd., surface-treated titanium dioxide, titanium oxide content: 87% by mass). Pigment 1 is rutile titanium dioxide, is produced by a chloride process and surface-treated with silica, zirconia, alumina, and organic compounds including polyol.

Pigment 2: Titanium oxide pigment (Ti-Pure™ R-960 for Coatings available from The Chemours Company, surface-treated titanium dioxide, titanium oxide content: 89% by mass). Pigment 2 is rutile titanium dioxide, is produced by a chloride process and surface-treated with amorphous silica and alumina, and without organic compounds.

Degassing agent: Benzoin

Surface conditioner 1 : Eastman Chemical Co., Ltd. trade name Benzoflex 352

Surface conditioner 2: BYK-360 P available from BYK Additives & Instruments

UVA: ultra-violet absorber, Tinuvin 479 available from BASF

HALS: light stabilizer, Tinuvin 111DL available from BASF

Curing catalyst: lOO-fold dilution product of dibutyl tin dilaurate (DBTDL) available from TRIGON Chemie GmbH

[00156] Production Example of Fl : In an autoclave, potassium carbonate (12.3 g) and KYOWAAD KW500SH (trade name of Kyowa Chemical Industry Co., Ltd. Hereinafter, also referred to as adsorbent) (4.5 g) were charged and vacuum degassed. Next, xylene (503 g), ethanol (142 g), CTFE (387 g), CHVE (326 g), and HBVE (84.9 g) were put into the autoclave and heated, and a tert-butylperoxypivalate 50% by mass xylene solution (20 mL) as a polymerization initiator was continuously added to carry out polymerization. After 11 hours, the autoclave was water- cooled to quench the polymerization, and the solution in the autoclave was filtered to obtain a solution containing first fluoropolymer Fl. The obtained solution was vacuum dried at 65 °C for 24 hours to remove the solvent and further vacuum dried at l30°C for 20 minutes to obtain Fl in a block shape. Fl was a polymer containing a CTFE based unit, a CHVE based unit, and a HBVE based unit at 50 mol%, 39 mol%, and 11 mol% relative to all the units contained in Fl, in this order respectively. The Tg of Fl was 52°C, the Mn was 10,000, and the hydroxyl value (hydroxyl number) was 50 mg KOH/g. [00157] Production Example of F2: Second fluoropolymer F2 in a block shape was obtained in the same manner as in the production example of Fl except that the amount of the monomer to be used was changed. F2 was a polymer containing a CTFE based unit, a CHVE based unit, and a HBVE based unit at 50 mol%, 25 mol%, and 25 mol% relative to all the units contained in F2, respectively. The Tg of F2 was 45°C, the Mn was 7,000, and the hydroxyl value (hydroxyl number) was 118 mg KOH/g.

[00158] Production of Composition: Each component was mixed using the high-speed mixer (manufactured by YU CHI MACHINERY Co., Ltd.) in the formulations shown in Table 1 to obtain a powdery mixture. The obtained mixture was melt-kneaded at a barrel setting temperature of l20°C using a twin-screw extruder (16 mm extruder manufactured by Thermo Prism Co., Ltd.) to obtain pellets. The obtained pellet was pulverized at 25°C using a pulverizer (manufactured by FRITSCH, product name: Rotor Speed Mill P14). The obtained powder was classified using a 150-mesh net to obtain a composition of each example having an average particle diameter of about 40 pm.

[00159] Preparation and Evaluation of Test Pieces: Using each of the compositions of each example, one side of the chromate-treated aluminum base material is electrostatically painted using an electrostatic painting equipment (Onoda Cement Co., Ltd. trade name GX3600C), and a powder paint layer is formed on the aluminum base material. The obtained powder paint layer-attached aluminum base was melt-cured by being held for 20 minutes in the atmosphere at 200°C as heat treatment, then it was cooled to 25 °C, and aluminum plates with each paint film with a thickness of 55 to 65 pm were obtained. Each of the obtained paint film-attached aluminum plates were evaluated as a test piece. The results are shown in Table 1.

[00160] Evaluation Method: [00161] 60-degree specular gloss: The 60-degree specular gloss of the paint film surface in the test piece was measured according to JIS K 5600-4-7 and evaluated according to the following criteria. The 60-degree specular gloss was measured with a variable angle gloss meter (UGV-6P, incident angle of 60-degree, manufactured by Suga Test Instruments Co., Ltd.).

S: 60-degree specular gloss is less than 40.

A: 60-degree specular gloss is no less than 40 and less than 60.

B: 60-degree specular gloss is no less than 60.

[00162] Impact resistance: Using a Dupont impact tester, a weight was dropped on the paint film side of the test piece, and the presence or absence of cracks and breakage at the drop point was observed.

A: No cracking or breakage occurs even when dropped from a height of 50 cm.

B: Cracks or breakage occurs when dropped from a height of 50 cm.

[00163] Surface smoothness: The smoothness of the paint film surface of the test pieces of Examples 1 to 6 was evaluated according to the following criteria using a standard plate for visual- determination of the smoothness by PCI (Powder Coating Institute). There are ten standard plates of 1 to 10, and the greater the number, the better the smoothness.

S: PCI is no less than 7.

A: PCI is no less than 5 and less than 7.

B: PCI is less than 5.

[00164] Pinhole: The paint film surface of the test piece was observed using SEM/EDX and evaluated by the following criteria. SEM/EDX images of the film surface of different paint films formed from the curing of the composition(s) show the surface morphology of the film surface. These images may be used to estimate the performance of the paint films formed from the composition(s). The images obtained by observing the paint film surface of the test piece using SEM/EDX are shown in Figures 1 to 6. Figures 1 to 6 each correspond to the paint film surfaces of Examples 1 to 6. Among Figures 1 to 6, Figures 1 to 3 have the fewest pinholes, Figure 4 has the second fewest pinholes, and Figures 5 to 6 have the third fewest pinholes.

S: The observation state of the paint film surface is similar to that of Figures 1 to 3 or is Figures 1 to 3 itself.

A: The observation state of the paint film surface is similar to that of Figure 4 or Figure 4 itself. B: The observation state of the paint film surface is similar to that of Figures 5 to 6 or is Figures 5 to 6 itself.

[00165] F/Ti: The paint film surface of the test pieces of Examples 1 to 6 was analyzed using SEM/EDX (TM3030 manufactured by Hitachi, Ftd.), and the ratio of the number of fluorine atoms and titanium atoms (F/Ti) on the paint film surface was calculated. The paint film surface was observed at 200 times, and EDX analysis was carried out at 100 times.

[00166] Flowability: The pellet flow test of the composition of Examples 1 to 6 was carried out according to ASTM D 4242-02. 1 g of the composition was pressed and formed into a pellet (disk-like) having a diameter of 0.5 inch, placed on an aluminum plate, and heated with a hot plate at 150°C. When the pellet started to melt, it was removed with the aluminum plate from the hot plate, the aluminum plate was installed so that it has an angle of 65 degrees with the horizontal direction, and the maximum distance (mm) of the pellet melts flowing down from the installation point was measured as the value of the pellet flow. The larger the pellet flow value, the more excellent the flowability of the composition and the more excellent the combination of melt viscosity and curing dynamics. [00167] Chemical resistance: A 10% hydrochloric acid aqueous solution was prepared with ion-exchanged water and special grade hydrochloric acid. In addition, a 10% nitric acid aqueous solution was prepared from ion-exchanged water and special grade nitric acid. Next, after 5 mL each of the hydrochloric acid aqueous solution and the nitric acid aqueous solution was dropped on the paint films of the test pieces of Examples 11 to 18, each was covered with a lid, held for four hours, and then washed with water. Then, the spot marks on the paint film were visually observed, and hydrochloric acid resistance and nitric acid resistance were evaluated based on the following criteria.

S: No swelling, dissolution of the paint film, or the like was confirmed.

A: Slight swelling, dissolution of the paint film, or the like was confirmed.

B: Clear swelling, dissolution of the paint film, or the like was confirmed.

[00168] The results are shown in the following Table. In the Table, the“OH(PE)/OH(F)” row shows the ratio of the number of hydroxyl functional groups in all the polyester to the total of the number of hydroxyl functional groups in all the first fluoropolymers and the number of hydroxyl functional groups in all the second fluoropolymers in the composition ((Hydroxyl number of the polyester x Content mass of the polyester) / (Hydroxyl number of the first fluoropolymer x Content mass of the first fluoropolymer + Hydroxyl number of the second fluoropolymer x Content mass of the second fluoropolymer). The“F/PE” row shows the mass ratio of the total content of the first fluoropolymer and the second fluoropolymer relative to the content of the polyester in the composition. The“F1/F2” row shows the mass ratio of the content of the second fluoropolymer to the content of the first fluoropolymer in the composition.



[00169] As shown in the Table, if the composition including the first fluoropolymer, the second fluoropolymer, the polyester, and the curing agent is used, a paint film, which is formed from the composition, excellent in low glossiness and excellent in impact resistance is obtained. Further, the films exhibit a reduced number of pinholes which improves the appearance of the films and provides excellent chemical resistance and weather resistance of the film. A paint film with a smooth surface and low glossiness are exhibited. These increase the performance of the films. Also, the films are not easily damaged due to impact during, for example, construction and installation processes. The excellent impact resistance, improved appearance, and excellent chemical resistance and weather resistance of the films also make the films ideal for commercial projects and buildings where the effects of impact, weathering and appearance are more frequently observed. As such, it becomes less costly and inexpensive to replace films because the films have a better performance than comparative films made from comparative powder coating compositions.

[00170] All combinations of the aforementioned embodiments throughout the entire disclosure are hereby expressly contemplated in one or more non-limiting embodiments even if such a disclosure is not described verbatim in a single paragraph or section above. In other words, an expressly contemplated embodiment may include any one or more elements described above selected and combined from any portion of the disclosure.

[00171] One or more of the values described above may vary by ± 5%, ± 10%, ± 15%, ± 20%, ± 25%, etc. so long as the variance remains within the scope of the disclosure. Unexpected results may be obtained from each member of a Markush group independent from all other members. Each member may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims. The subject matter of all combinations of independent and dependent claims, both singly and multiply dependent, is herein expressly contemplated. The disclosure is illustrative including words of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the disclosure may be practiced otherwise than as specifically described herein.

[00172] It is also to be understood that any ranges and subranges relied upon in describing various embodiments of the present disclosure independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and/or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present disclosure, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range“of from 0.1 to 0.9” may be further delineated into a lower third, i.e. from 0.1 to 0.3, a middle third, i.e. from 0.4 to 0.6, and an upper third, i.e. from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as“at least,”“greater than,”“less than,”“no more than,” and the like, it is to be understood that such language includes subranges and/or an upper or lower limit. As another example, a range of “at least 10” inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range“of from 1 to 9” includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1, which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.




 
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