PRETREATMENT FORMULATION AND A CORRESPONDING INK SET

TECHNOLOGICAL FIELD

The invention generally contemplates a novel pretreatment formulation and a corresponding ink-set comprising same.

BACKGROUND OF THE INVENTION

Fabrics and other textile materials have been used as substrates for inkjet printing. Despite their common use, fabrics present a challenge due to their structure and composition. Without the ability of a pigment to securely associate to or penetrate the fabric, the resulting printed image may be deficient.

Many technologies have been developed over the years to at least partially overcome difficulties associated with or resulting from low color intensity, fuzziness, especially at the edges of the pattern or image. Some of these technologies offer improvements in the printing process rather than in treating the substrate, e.g., textile or fabric.

GENERAL DESCRIPTION

There still exists a need to provide printed patterns that not only securely adhere to fabric surfaces, but also present a high print quality, wash-fastness, and mechanical durability; minimizing loss in tensile strength and enhancing tear resistance. The inventors have successfully developed and now provide a provision of pretreatment formulations, which not only endow the fabric with better and improved mechanical properties, but can also provide a superior recipient surface for ink patterning, meeting all of the above desired attributes.

In its broadest aspect, the invention provides a pretreatment formulation comprising at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a derivative thereof. As will be further detailed hereinbelow, the formulation is not a colored ink formulation, as it does not comprise a pigment or a dye, but rather a formulation used to form a recipient film or coat on which an ink formulation may be applied or patterned. Hence, pretreatment formulations of the invention are configured and used to precede application of an ink formulation on a substrate, e.g., fabric or textile, and allow ink immobilization on regions of a substrate on which the ink patterns are to be subsequently formed.

As used herein, the term pretreatment formulation" encompasses application of a formulation of the invention at any time prior to application, patterning or printing of an ink formulation. The application of the ink is intended to be on a film or a coat of the pretreatment formulation at any time following formation of the film or coat (the recipient film or coat). The term should be understood to mean application on any substrate material, by any application means, forming a film or a coat of any shape and size.

In a first of its aspects, the invention provides a VAE-based pretreatment formulation comprising at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative.

The invention further provides a formulation for use in forming a recipient surface, wherein the formulation comprises at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative. As will be further detailed below, the recipient surface may be tailored for subsequent deposition of an ink formulation, wherein the deposition may be immediately following deposition of the formulation of the invention (so called ‘wet-on- wet’ application), or at any time thereafter (so called ‘wet-on-dry' application).

While formulations of the invention may be applied onto a surface region of a substrate by any means known in the art, including spraying, brushing, stamping, printing, etc., another means for application of a pretreatment formulation of the invention is by use of a digital inkjet printing unit. Thus, further provided is a formulation for digital inkjet printing, the formulation comprises or consists at least one ink fixation agent, at least one vinyl acetate/ethylene copolymer (VAE) and/or a derivative thereof and an aqueous carrier.

The invention further provides an ink-set comprising a pretreatment formulation and an ink formulation, wherein

-the pretreatment formulation comprises at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative, and wherein

-the ink formulation comprises a pigment or a dye and is free of at least one vinyl acetate/ethylene copolymer (VAE) or a derivative thereof. In other words, pretreatment formulations of the invention are configured and adapted for use with ink formulations that are free of a combination of ink fixation agents, such as metal salts, and at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative; or are free of at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative. Putting it differently, in ink-sets of the invention, as defined herein, the at least one vinyl acetate/ethylene copolymer (VAE) or the VAE derivative is comprised in the pretreatment formulation only.

Each of the pretreatment and ink formulations may comprise a carrier, such as water or a water-based medium.

Pretreatment formulations of the invention may comprise in addition to the ink fixation agent and the VAE and/or derivative thereof, a carrier and potentially also additives such as defoamers, softeners, latent acids, latent bases, preservatives, biocides, and wetting agents/surf actants. When added to a pretreatment formulation of the invention, these additives are not regarded as activating agents or pH adjusting agents as they do not impose any change to the pretreatment coating formed and/or dried. The pretreatment formulations of the invention are free of or do not comprise activating agents, polymerizing or crosslinking agents, alkali soluble agents, penetrating agents, wax materials, pH-adjusting agents, isocyanates or block isocyanates, carbodiimides, polycarbodiimide, epoxy crosslinking agent, organic or inorganic acids and bases, ethylene-vinyl acetate (EVA), polyvinyl acetate (PVAc), ethylene-vinyl alcohol (EVOH), cellulose and derivatives thereof (including methyl celluloses, hydroxy ethyl cellulose and others). As a person versed in the art would appreciate, the VAE and/or VAE derivative used according to the inventions is capable of self-crosslinking. When heated, the substituents on the VAE/VAE derivative react with other substituents to crosslink the substituted VAE polymers. Therefore, no activation agents are needed.

In some embodiments, pretreatment formulations of the invention are free of polyvinyl alcohol (PVOH).

Pretreatment formulations of the invention may further exclude resins and polymeric materials other than the VAE or the derivative thereof.

As noted herein, pretreatment formulations of the invention exclude acids and bases, yet may comprise latent acids or latent bases. The formulations further exclude pH-adjusting agents. It should be clarified that presence of the latent acids or bases does not modify pH of the formulation and thus, as stated above, the latent materials do not constitute actual acids or bases or cannot be regarded as active until the acid or base is generated by thermal decomposition of the latent forms following deposition of the ink and curing of the ink pattern. In other words, the latent acids or latent bases are configured for activation by thermal stimulation, i.e., application of heat, to release an acid or base, respectively, for catalyzing or accelerating the self-crosslinking reaction.

The latent acid or base may be selected amongst such compounds that decompose upon exposure to heat or upon exposure to a suitable reaction condition, e.g., hydrolysis, or to a material (e.g., in the ink formulation), to provide an acid or a base. In some embodiments, the latent acids or bases are selected amongst such materials having thermal activation (to form the acid or base) that is higher than 105°C, or above 120°C, or above 130°C, or above 150°C, or between 130 and 150°C, or between 150 and 180°C. The acid or base generated at elevated temperatures, as above, may catalyze a selfcrosslinking reaction between functional groups present on any VAE polymer present in the pretreatment formulation (e.g., between functional groups on VAE chains where a single type of e.g., a substituted VAE polymer is present, and/or between the VAE chains of different substituted VAE types or derivatives in case one or more VAE or derivatives thereof are present in the pretreatment formulation), accelerating a reaction between reactive chemical moieties covalently bonded to the VAE derivative polymer backbone, as further described hereinbelow.

Exemplary latent acids include, but are not limited to, esters, sulfonic acid esters, fluorinated sulfonic acid esters, phosphonic acid esters and nitriles. The latent base may be selected amongst metal oxides which yield an alkaline material under suitable reaction conditions. Such latent bases may be selected from oxides of alkali or alkaline earthmetals such as barium oxide, calcium oxide, lithium oxide, or magnesium oxide.

The at least one softener may be selected amongst commercially available polysiloxanes such as Rudolf group (RUCOFIN MISP EXTRA, RUCOFIN GWE, RUCOFIN HPU, RUCOFIN X-GWA NEW, RUCOFIN SIQ NEW), WACKER (i.e., POWERSOFT UP® 68, POWERSOFT® AE 61, POWERSOFT® CF 20), Momentive (Magnasoft 68) and others.

The at least one defoamer may be selected amongst commercially available defoamers such as Borchers (Borchers® AF 1171, Borchi® Burst DFS 600, Borchi® Burst DFS 500), Evonik (AIRASE® 4500, AIRASE® 4655, AIRASE® 5355, TEGO® Foamex 832, TEGO® Foamex 833, Tego Foamex 852. TEGO® Foamex 8850), BASF (FoamStar® ED 2522, FoamStar® NO 2306, FoamStar® SI 2213) and others.

In some embodiments, the carrier may be water or containing water.

In some embodiments, the carrier may comprise an organic solvent, optionally a water miscible organic solvent.

In some embodiments, the organic solvent may be selected amongst methanol, ethanol, propanol, iso-propanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, pentane, hexane, heptane, methyl acetate, ethyl acetate, propyl acetate, derivatives thereof, and combinations thereof; l-methoxy-2-propanol, 2-methoxy ethanol, 2-ethoxy ethanol, l-methoxy-2-acetoxy propane, derivatives thereof, and combinations thereof; tripropylene glycol monomethyl ether, tripropylene glycol-n-butyl ether, propylene glycol phenyl ether, derivatives thereof, and combinations thereof.

In some embodiments, pretreatment formulations of the invention consist at least one ink fixation agent, e.g., a metal salt, at least one vinyl acetate/ethylene copolymer (VAE) and/or a derivative thereof and a carrier. The formulation may comprise at least one additive, as defined.

In some embodiments, pretreatment formulations of the invention consist at least one ink fixation agent such as a metal salt, at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative, a carrier and at least one additive selected from a defoamer, a softener, a latent acid and a latent base.

Thus, formulations of the invention may be generally one or more of the following:

-a formulation consisting (or comprising) at least one fixation agent, VAE and a carrier;

-a formulation consisting (or comprising) at least one fixation agent, VAE, VAE derivative and a carrier;

-a formulation consisting (or comprising) at least one fixation agent, VAE derivative and a carrier;

-a formulation consisting (or comprising) at least one fixation agent, VAE, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) at least one fixation agent, VAE, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base; -a formulation consisting (or comprising) at least one fixation agent, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) a metal salt, VAE and a carrier;

-a formulation consisting (or comprising) a metal salt, VAE, VAE derivative and a carrier;

-a formulation consisting (or comprising) a metal salt, VAE derivative and a carrier;

-a formulation consisting (or comprising) a metal salt, VAE, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) a metal salt, VAE, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) a metal salt, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) an ammonium salt, VAE and a carrier;

-a formulation consisting (or comprising) an ammonium salt, VAE, VAE derivative and a carrier;

-a formulation consisting (or comprising) an ammonium salt, VAE derivative and a carrier;

-a formulation consisting (or comprising) an ammonium salt, VAE, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) an ammonium salt, VAE, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) an ammonium salt, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) a metal salt, an ammonium salt, VAE and a carrier;

-a formulation consisting (or comprising) a metal salt, an ammonium salt, VAE, VAE derivative and a carrier;

-a formulation consisting (or comprising) a metal salt, an ammonium salt, VAE derivative and a carrier; -a formulation consisting (or comprising) a metal salt, an ammonium salt, VAE, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) a metal salt, an ammonium salt, VAE, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base;

-a formulation consisting (or comprising) a metal salt, an ammonium salt, VAE derivative, a carrier and an additive selected form defoamer, a softener, a latent acid and a latent base; wherein in each of the aforementioned formulations, each component is as defined and selected herein, and wherein each formulation constitutes an independent embodiment of the invention.

The at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative may be provided as a single material or as a mixture of two or more materials, as an aqueous dispersion, as a powder, as an emulsion or in any other form. In some cases, it may be provided pre-dispersed in an aqueous medium. In other cases, it may be provided as an emulsion.

The VAE or the VAE derivative thereof may be provided in combination with at least one surfactant.

As known in the art, “vinyl acetate/ethylene copolymer (VAE)” is a non-ionic copolymerization product of vinyl acetate and ethylene, in which the vinyl acetate content may range between 60 and 95%, and the ethylene content may range between 5 and 40% of the total weight of the copolymer. As also known, VAE is not the same as ethylene vinyl acetate (EVA) copolymers, in which case the fraction of vinyl acetate and ethylene may be different from the herein defined vinyl acetate and ethylene content. Thus, EVA is not the same material and may thus be excluded from formulations of the invention.

In some embodiments, a VAE used in accordance with the invention has a vinyl acetate fraction (w/w) that is at least 60%, or is between 60 and 95%, or between 60 and 90%, or between 60 and 85%, or between 60 and 80%, or between 60 and 75%.

In some embodiments, the fraction (w/w) of the ethylene in the VAE may be 5%, or between 5 and 40%, or between 5 and 35%, or between 5 and 30%, or between 5 and 25%, or between 5 and 20%, or between 5 and 15%. The chemical structure of VAE is shown below. Structure (I) depicts the repeating units derived from vinyl acetate and ethylene at a ratio m/n as detailed herein, provided that the number of repeating units provides a material having ethylene in a weight/weight ratio that does not exceed 40wt%.

In the structure (I) shown, n, designates the relative number of repeating units derived from ethylene, and may be 5%, or between 5 and 40%, or between 5 and 35%, or between 5 and 30%, or between 5 and 25%, or between 5 and 20%, or between 5 and

15%. Integer m, designates the relative number of repeating units derived from vinyl acetate and may be 60%, or is between 60 and 95%, or between 60 and 90%, or between 60 and 85%, or between 60 and 80%, or between 60 and 75%.

Alternatively, a ratio between m and n (m/n) may be defined in terms of the number of monomers present in the compound of structure (I). In some embodiments, the ratio m/n is in favor of m, namely the VAE is structured of greater amount (number) of vinyl acetate units. In some embodiments, a ratio between m and n (m/n) is in favor of n, namely the VAE is structured of greater amount (number) of ethylene units.

In some embodiments, the ratio m/n may be between 50:1 and 1:50. In some embodiments, the m/n ratio may be between 20:1 and 1:20. In some embodiments, the ratio m/n may be 50:1, 40:1, 30:1, 20:1, 15:1, 10:1, 5:1, 2:1, 1:1, 1:2, 1:5, 1:10, 1:15, 1:20, 1:30, 1:35, 1:40, or 1:50 m/n, provided that the fraction (w/w) of the ethylene in the VAE does not exceed 40wt%.

In some embodiments, the ratio m/n may be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 3:2, 5:2, 7:2, 9:2, 11:2, 13:2, 15:2, 17:2, 19:2 m/n, provided that the fraction (w/w) of the ethylene in the VAE does not exceed 40wt%.

In some embodiments, the ratio m/n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In some embodiments, the relative number of vinyl acetate moieties to the ethylene moieties is 2 times as large, or 3 times or 4 times or 5 times or is 2 times to 20 times as large.

In some embodiments, irrespective of the number of monomers (represented by integers m and n, as defined for a compound of structure (I)), the weight ratio between the vinyl acetate and ethylene monomers is such that vinyl acetate fraction (w/w) is at least 60%, and the ethylene fraction (w/w) is no more than 40%.

As used herein, and in some cases, the percentage values provided may be exact or may vary within ±10% of the indicated value.

The VAE may be manufactured by copolymerization of vinyl acetate and ethylene, at desired ratios, according to known synthetic protocols. Examples of such protocols are disclosed in WO2019/126913, US patent application no. 2012/015201, US Patent No. 4,267,090 and others, each of which being exemplary and incorporated herein by reference for teaching VAE preparation methods. Alternatively, the VAE may be purchased from commercial sources, as further disclosed herein.

Formulations of the invention may comprise VAE, any one or more non-ionic derivative thereof or combinations of same. The phrase “VAE and/or a derivative thereof’ or “VAE and/or VAE derivative” encompass formulations comprising or consisting VAE; formulations comprising or consisting at least one VAE derivative; and formulations comprising or consisting VAE and at least one VAE derivative.

A “VAE derivative s as used herein, is any chemically modified (optionally nonionic) VAE, wherein:

-a further monomer is introduced along the VAE chain, wherein said monomer is one or a plurality of monomeric recuring units, different from vinyl acetate and ethylene, and optionally comprising at least one functionality permitting crosslinking; or

-one or both of vinyl acetate and ethylene are modified, functionalized or derivatized with a functional group permitting crosslinking; or

-at least a portion (some or all) of the vinyl acetate monomers and/or at least a portion (some or all) of the ethylene monomers are chemically functionalized; or

-at least some (or all) of the vinyl acetate monomers are chemically functionalized, but none of the ethylene monomers are chemically functionalized; or

-none of the vinyl acetate monomers are chemically functionalized, but some or all of the ethylene monomers are chemically functionalized; or wherein -the backbone of a VAE polymer formed by reacting vinyl acetate monomers with ethylene monomers is chemically functionalized.

The VAE derivative may be a modified VAE in which the chemical functionalization is selected to permit crosslinking, e.g., self-crosslinking. The derivative may be prepared by either reacting vinyl acetate monomers with ethylene monomers, where some or all of the vinyl acetate monomers and/or some or all of the ethylene monomers are chemically functionalized; or some or all of the vinyl acetate monomers are chemically functionalized but none of the ethylene monomers are chemically functionalized; or none of the vinyl acetate monomers are chemically functionalized but some or all of the ethylene monomers are chemically functionalized; or wherein the backbone of a VAE polymer formed by reacting vinyl acetate monomers with ethylene monomers is chemically functionalized.

For example, and as further detailed hereinbelow, VAE derivatives may be in a form of copolymerized vinyl acetate (VA) monomers and/or ethylene (E) monomers, wherein at least one of the VA and E monomers is N-methylol-functionalized, wherein the N-methylol is derived from N-methylol-based materials such as N-methylol- acrylamide (NMA), N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid eaters, N-methylol amides of vinyl aromatic acids such as N-methylol p-vinylbenzamide, and others.

In some embodiments, the VAE derivative is of structure (II), wherein at least one of variants R1 through R14 is a functional group selected from alcohols, amines, vinyl groups, carboxyl groups, silanols, and others, and wherein each of nl, n2, ml and m2, independently of the other is an integer being at least 1. In some embodiments, in structure (II), one or at least one (but- in some embodiments- not all) of variants R1 through R14 is selected as above and all other variants R1 through R14 are H.

In some embodiments, at least one variant R1 through R14 is derived from N- (hydroxymethyl)formamide (e.g., an N-(hydroxymethyl)carbamoyl group).

In some embodiments, nl and n2 constitute together integer n as defined above. In some embodiments, ml and m2 constitute together integer m as defined above. The ratio (ml+m2) and (nl+n2) may be determined based on the molecular weight of the functionalities making up a compound of formula (II). In some cases, the ratio may be selected based on the ratio used for VAE above. In other cases, the ratio may exceed or fall outside of the ratio defined above for m/n. For the sake of brevity, however, a ratio between (ml+m2) and (nl+n2) may be regarded as a ratio m/n, and may be selected to be between 50:1 to 1:50.

The invention further provides a pretreatment formulation comprising at least one ink fixation agent and at least one compound of formula (II): wherein at least one of variants R1 through R14 is a functional group selected from alcohols, amines, vinyl groups, carboxyl groups, silanols, and others, and wherein each of nl, n2, ml and m2, independently of the other is an integer being at least 1.

In some embodiments, in structure (II), one or at least one (but- in some embodiments- not all) of variants R1 through R14 is selected as above and all other variants R1 through R14 are H.

In some embodiments, at least one variant R1 through R14 is derived from N- (hydroxymethyl)formamide (e.g., an N-(hydroxymethyl)carbamoyl group).

In some embodiments, nl and n2 constitute together integer n as defined above. In some embodiments, ml and m2 constitute together integer m as defined above. Thus, a ratio between (ml+m2) and (nl+n2) is as defined hereinabove for m/n. The VAE derivative may be a self-crosslinkable polymer, wherein functionalization introduces reactive moieties that can react with each other to selfcrosslink the VAE derivative.

As used herein, the term “ self -crosslinkable in reference to a VAE derivative material, as defined, may be a VAE material functionalized with reactive chemical moieties or groups or functionalities or monomers structured to undergo self-crosslinking, namely, to attach or associate or to form bonds with other VAE derivative polymers in the formulation, under predefined conditions. While internal linking (bonding) between different functional groups on the same VAE derivative polymer is possible, the inter- molecular self-crosslinking of the VAE derivative polymer allows for a more robust dried/cured film or coat of the pretreatment of the invention.

The reactive moieties or functional groups may be selected from alcohols, amines, vinyl groups, carboxyl groups, silanols and others. These groups may be added to the VAE molecule during the copolymerization process yielding VAE derivative or grafted thereto.

Non-limiting examples of VAE derivatives include copolymerized vinyl acetate (VA) monomers with N-methylol-functionalized ethylene monomers derived from N- methylol-based materials such as N-methy lol- acrylamide (NMA), N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid eaters, N-methylol amides of vinyl aromatic acids such as N-methylol p-vinylbenzamide, and others (or additionally with ethylene monomers (E), which are not functionalized).

In some embodiments, the VAE derivative is a vinyl acetate copolymerized with an ethylene functionalized with N-methylol derived from NMA.

In some embodiments, the VAE derivative is a copolymerization product of vinyl acetate, ethylene and NMA or any N-methylol derivative selected from N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid eaters, N-methylol amides of vinyl aromatic acids such as N-methylol p-vinylbenzamide.

Non-limiting examples of VAE derivatives include copolymerized ethylene (E) monomers with N-methylol-functionalized vinyl acetate (VA) monomers derived from N-methy lol-based materials such as N-methy lol-acrylamide (NMA), N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid eaters, N-methylol amides of vinyl aromatic acids such as N-methylol p-vinylbenzamide, and others (or additionally with vinyl acetate monomers (VA), which are not functionalized).

In some embodiments, the VAE derivative is an ethylene copolymerized with a vinyl acetate functionalized with N-methylol derived from NMA (or additionally with vinyl acetate monomers, which are not functionalized).

Thus, in some embodiments, a pretreatment formulation according to the invention may comprise a VAE derivative such as a copolymerization product of vinyl acetate with an ethylene functionalized with N-methylol derived from NMA; or a copolymerization product of ethylene with a vinyl acetate functionalized with N-methylol derived from NMA.

As used herein, the term copolymerization product encompasses a copolymer of the two or more components that are precursors to the copolymerization reaction. For example, the expression “copolymerization product of vinyl acetate with an ethylene functionalized with N-methylol derived from NMA” encompasses any product that is a copolymer of vinyl acetate and ethylene monomers that are functionalized with an N- methylol group derived from NMA. Such copolymers may also include unfunctionalized ethylene monomers. Same applies to an expression such as “copolymerization product of ethylene with a vinyl acetate functionalized with N-methylol derived from NMA”. This expression encompasses any product that is a copolymer of ethylene and vinyl acetate monomers that are functionalized with an N-methylol group derived from NMA, wherein the copolymers may also include unfunctionalized vinyl acetate monomers.

In some embodiments, the pretreatment formulation may comprise VAE and/or a VAE derivative, as defined.

In some embodiments, the formulation comprises an aqueous copolymer dispersion of any of the VAE derivatives mentioned herein , e.g., being commercially available from a variety of sources such as Celanese under Vinamul and Mowilith series, and Wacker Chemie AG under the VINNAPAS series, or any equivalent commercially available formulation.

The at least one ink fixation agent may be any such material that upon contact with the ink is capable of instantaneously increasing the ink viscosity, limiting or diminishing ink bleeding. Typically, the fixation agent is a cationic material. The cationic material may be provided in the form of a salt of a metal or of an organic material or of a polymeric material. Examples of ink fixation agents include metal salts, salts of amines such as diamines, triamines and quaternary ammonium salts, sulfonium salts and phosphonium salts.

In some embodiments, the ammonium salt may be selected from a polyethyleneimine salt, a polyvinyl amine salt, a polyallyl amine salt, a polydimethyl aminoethyl methacrylate quaternary salt, a polydiallyl dimethyl ammonium salt, a diallylamine acrylic amide copolymer salt, and a quaternary ammonium salt of polystyrene.

In some embodiments, the ink fixation agent is an ammonium salt, such as a polyquaternary ammonium salt. Non-limiting examples include polidronium chloride, poly [bis(2-chloroethyl) ether-alt- 1 ,3-bis[3-(dimethylamino)propyl]urea] quaternized, poly (diallyldimethylammonium chloride) , poly (acrylamide-co-diallyldimethyl ammonium chloride) and nonanediamide N,N'-bis(3-(dimethylamino)propyl)- polymer with 1 , 1 '-oxybis(2-chloroethane) .

In some embodiments, the ink fixation agent is poly diallyl dimethyl ammonium salt such as poly(diallyldimethylammonium chloride).

In some embodiments, the ink fixation agent is a sulfonium salt such as poly(4- vinylbenzyltetrahydrothiophenium tetrafluoroborate) and poly(P-hydroxy sulfonium tetrafluoroborate) .

In some embodiments, the ink fixation agent is a phosphonium salt, such as poly [tributyl(4-vinylbenzyl)phosphonium salt] and poly(glyceryl methacrylate bis- tributylphosphonium chloride).

In some embodiments, the ink fixation agent is provided as a cationic copolymer or cationic homopolymer.

In some embodiments, the ink fixation agent is a mixture of two or more different ink fixation agents, one of which being optionally a metal salt.

In some embodiments, the ink fixation agent is a metal salt. A metal salt used along with VAE or a derivative thereof is any cationic form of a metal when provided with at least one organic or inorganic anion. The at least one metal salt may be provided as a single salt or as a combination of two or more salts. The selection of salts used, and whether the salt used is provided as a single component or as a combination of salts (namely one or more salts) may depend on a variety of factors, including, inter alia, its solubility in water or in a medium containing water and a co-solvent and its ability to form a receptive layer; thus, contributing to ink fixation onto the substrate.

The at least one metal salt may be selected from monovalent metal salts, divalent metal salts, trivalent metal salts and combinations thereof. The metal may be sodium, calcium, aluminum, copper, zinc, cobalt, nickel, magnesium, and others. The anion used as the counter ion may be an inorganic anion or an organic anion. In some embodiments, the metal salt is at least one inorganic salt and thus the anion component of the metal salt is an inorganic anion which may optionally be a chloride, a fluoride, a bromide, an iodide, a nitride, a sulfate, or phosphate anion.

Examples of suitable metal salts of monovalent cations (and counter inorganic or organic anions) include, but are not limited to, lithium chloride, lithium acetate, lithium carbonate, lithium nitrate, lithium phosphate, sodium chloride, sodium acetate, sodium carbonate, sodium nitrate, sodium phosphate, potassium acetate, potassium chloride, potassium carbonate, potassium phosphate, potassium nitrate, copper nitride, copper sulfate, silver chloride, silver nitride, silver sulfate, silver acetate, silver citrate, silver propionate, silver phosphate, gold chloride, gold nitride, gold sulfate, gold acetate, gold citrate, gold propionate, and gold phosphate.

In some embodiments, the at least one metal salt is not a monovalent metal salt.

Examples of suitable salts of divalent cations (and counter inorganic or organic anions) include, but are not limited to, magnesium chloride, magnesium acetate, magnesium carbonate, magnesium nitrate, magnesium phosphate, calcium chloride, calcium acetate, calcium carbonate, calcium nitrate, calcium nitrate, calcium phosphate, zinc chloride, zinc acetate, zinc carbonate, zinc nitrate, zinc phosphate, copper chloride, copper acetate, copper carbonate, copper nitrate, copper phosphate, tin chloride, tin acetate, tin carbonate, tin nitrate, tin phosphate, ferrous chloride, ferrous acetate, ferrous carbonate, ferrous nitrate, ferrous phosphate, and combinations thereof.

In some embodiments, the salt is a calcium salt. Non-limiting examples of calcium salts include CaCh, CaF2, CaBn. Cah, calcium carbonate, calcium acetate (CaAc2) and mixed halide salts such as CalBr, CaCIBr and others. In some embodiments, the salt is CaCh.

Pretreatment formulations of the invention may comprise an amount of VAE or a derivative thereof that is sufficient to achieve a robust film or coat matrix of the VAE or a derivative thereof and comprising the at least one aggregating, and therefore fixating, metal salt agent. In some embodiments, formulations of the invention may comprise between 0.1 and 20 wt% of VAE or a derivative thereof. In some embodiments, the amount may be between 0.1 and 15 wt%, 0.1 and 10 wt%, 0.2 and 20 wt%, 0.2 and 15 wt%, 0.2 and 10 wt%, 0.3 and 20 wt%, 0.3 and 15 wt%, 0.3 and 10 wt%, 0.4 and 20 wt%, 0.4 and 15 wt%, 0.4 and 10 wt%, 0.5 and 20 wt%, 0.5 and 15 wt%, 0.5 and 10 wt%, 2 and 10 wt%, 3 and 10 wt%, 4 and 10 wt%, 5 and 10 wt%, 6 and 10 wt%, 7 and 10 wt%, 8 and 10 wt%, 2 and 15 wt%, 3 and 15 wt%, 4 and 15 wt%, 5 and 15 wt%, 6 and 15 wt%,

7 and 15 wt%, 8 and 15 wt%, 9 and 15 wt%, 5 and 20 wt%, 6 and 20 wt%, 7 and 20 wt%,

8 and 20 wt%, 9 and 20 wt%, or is 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10wt%.

In some embodiments, formulation may comprise a VAE derivative and calcium chloride in a ratio of 4.4:0.5, 8.3:0.9 or 8.3:15. In some embodiments, a formulation comprises a VAE derivative, poly(diallyldimethylammonium chloride and CaCh at a ratio of 3.3: 1.1:6 or 5: 1.7:9.

The amount of the at least one fixation agent, e.g., metal salt, is selected to increase pigment and or binder (present in the ink) fixation to the receptive surface treated with the pretreatment formulation of the invention. Where the fixation agent is a metal salt, the amount of the metal salt may thus vary between 0.1 and 20wt%. In some embodiments, the amount may be between 0.1 and 15 wt%, 0.1 and 10 wt%, 0.2 and 20 wt%, 0.2 and 15 wt%, 0.2 and 10 wt%, 0.3 and 20 wt%, 0.3 and 15 wt%, 0.3 and 10 wt%, 0.4 and 20 wt%, 0.4 and 15 wt%, 0.4 and 10 wt%, 0.5 and 20 wt%, 0.5 and 15 wt%, 0.5 and 10 wt%, 0.1 and 5 wt%, 0.2 and 5 wt%, 0.3 and 5 wt%, 0.4 and 5 fwt%, 0.5 and 5 wt%, 0.6 and 5 wt%, 0.7 and 5 wt%, 0.8 and 5 wt%, 0.9 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 3 and 5 wt%, 0.1 and 4 wt%, 0.1 and 3 wt%, 0.1 and 2 wt%, 0.2 and 4 wt%, 0.2 and 3 wt%, 0.2 and 2 wt%, 0.2 and 1 wt%, 0.3 and 4 wt%, 0.3 and 3 wt%, 0.3 and 2 wt%, 0.4 and 4 wt%, 0.4 and 3 wt%, 0.4 and 2 wt%, 0.5 and 4 wt%, 0.5 and 3 wt%, 0.5 and 2 wt%, or is 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10wt%.

In some embodiments, the pretreatment formulation may comprise VAE or a derivative thereof in an amount between 0.1 and 20 wt% and at least one metal salt in an amount between 0.1 and 20 wt%.

In some embodiments, the pretreatment formulation may comprise VAE or a derivative thereof in an amount between 2 and 10 wt%, 3 and 10 wt%, 4 and 10 wt%, 5 and 10 wt%, 6 and 10 wt%, 7 and 10 wt%, 8 and 10 wt%, 2 and 15 wt%, 3 and 15 wt%, 4 and 15 wt%, 5 and 15 wt%, 6 and 15 wt%, 7 and 15 wt%, 8 and 15 wt%, 9 and 15 wt%,

5 and 20 wt%, 6 and 20 wt%, 7 and 20 wt%, 8 and 20 wt%, or 9 and 20 wt%, and at least one metal salt in an amount between 0.1 and 5 wt%, 0.2 and 5 wt%, 0.3 and 5 wt%, 0.4 and 5 wt%, 0.5 and 5 wt%, 0.6 and 5 wt%, 0.7 and 5 wt%, 0.8 and 5 wt%, 0.9 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 3 and 5 wt%, 0.1 and 4 wt%, 0.1 and 3 wt%, 0.1 and 2 wt%, 0.2 and 4 wt%, 0.2 and 3 wt%, 0.2 and 2 wt%, 0.2 and 1 wt%, 0.3 and 4 wt%, 0.3 and 3 wt%, 0.3 and 2 wt%, 0.4 and 4 wt%, 0.4 and 3 wt%, 0.4 and 2 wt%, 0.5 and 4 wt%, 0.5 and 3 wt%, 0.5 and 2 wt%.

In some embodiments, the pretreatment formulation may comprise VAE or a derivative thereof in an amount between 2 and 10 wt%, and at least one metal salt in an amount between 0.1 and 5 wt%, 0.2 and 5 wt%, 0.3 and 5 wt%, 0.4 and 5 wt%, 0.5 and 5 wt%, 0.6 and 5 wt%, 0.7 and 5 wt%, 0.8 and 5 wt%, 0.9 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 3 and 5 wt%, 0.1 and 4 wt%, 0.1 and 3 wt%, 0.1 and 2 wt%, 0.2 and 4 wt%, 0.2 and 3 wt%, 0.2 and 2 wt%, 0.2 and 1 wt%, 0.3 and 4 wt%, 0.3 and 3 wt%, 0.3 and 2 wt%, 0.4 and 4 wt%, 0.4 and 3 wt%, 0.4 and 2 wt%, 0.5 and 4 wt%, 0.5 and 3 wt%, 0.5 and 2 wt%.

In some embodiments, the pretreatment formulation may comprise VAE or a derivative thereof in an amount between 5 and 10 wt% and at least one metal salt in an amount between 0.1 and 5 wt%, 0.2 and 5 wt%, 0.3 and 5 wt%, 0.4 and 5 wt%, 0.5 and 5 wt%, 0.6 and 5 wt%, 0.7 and 5 wt%, 0.8 and 5 wt%, 0.9 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 3 and 5 wt%, 0.1 and 4 wt%, 0.1 and 3 wt%, 0.1 and 2 wt%, 0.2 and 4 wt%, 0.2 and 3 wt%, 0.2 and 2 wt%, 0.2 and 1 wt%, 0.3 and 4 wt%, 0.3 and 3 wt%, 0.3 and 2 wt%, 0.4 and 4 wt%, 0.4 and 3 wt%, 0.4 and 2 wt%, 0.5 and 4 wt%, 0.5 and 3 wt%, 0.5 and 2 wt%.

In some embodiments, the pretreatment formulation may comprise VAE or a derivative thereof in an amount between 6 and 15 wt% and at least one metal salt in an amount between 0.1 and 5 wt%, 0.2 and 5 wt%, 0.3 and 5 wt%, 0.4 and 5 wt%, 0.5 and 5 wt%, 0.6 and 5 wt%, 0.7 and 5 wt%, 0.8 and 5 wt%, 0.9 and 5 wt%, 1 and 5 wt%, 2 and 5 wt%, 3 and 5 wt%, 0.1 and 4 wt%, 0.1 and 3 wt%, 0.1 and 2 wt%, 0.2 and 4 wt%, 0.2 and 3 wt%, 0.2 and 2 wt%, 0.2 and 1 wt%, 0.3 and 4 wt%, 0.3 and 3 wt%, 0.3 and 2 wt%, 0.4 and 4 wt%, 0.4 and 3 wt%, 0.4 and 2 wt%, 0.5 and 4 wt%, 0.5 and 3 wt%, 0.5 and 2 wt%. In some embodiments, the pretreatment formulation may comprise VAE or a derivative thereof in an amount between 2 and 10 wt%, 3 and 10 wt%, 4 and 10 wt%, 5 and 10 wt%, 6 and 10 wt%, 7 and 10 wt%, 8 and 10 wt%, 2 and 15 wt%, 3 and 15 wt%,

4 and 15 wt%, 5 and 15 wt%, 6 and 15 wt%, 7 and 15 wt%, 8 and 15 wt%, 9 and 15 wt%,

5 and 20 wt%, 6 and 20 wt%, 7 and 20 wt%, 8 and 20 wt%, or between 9 and 20 wt%, and at least one metal salt in an amount between 0.1 and 5 wt%.

In some embodiments, the pretreatment formulation may comprise VAE or a derivative thereof in an amount between 2 and 10 wt%, 3 and 10 wt%, 4 and 10 wt%, 5 and 10 wt%, 6 and 10 wt%, 7 and 10 wt%, 8 and 10 wt%, 2 and 15 wt%, 3 and 15 wt%,

4 and 15 wt%, 5 and 15 wt%, 6 and 15 wt%, 7 and 15 wt%, 8 and 15 wt%, 9 and 15 wt%,

5 and 20 wt%, 6 and 20 wt%, 7 and 20 wt%, 8 and 20 wt%, or 9 and 20 wt%, and at least one metal salt in an amount between 0.3 and 3 wt%, 0.3 and 2 wt%, 0.4 and 4 wt%, 0.4 and 3 wt%, 0.4 and 2 wt%, 0.5 and 4 wt%, 0.5 and 3 wt%, or between 0.5 and 2 wt%.

In some embodiments, in a formulation of the invention, the weight amount of VAE or a derivative thereof is greater than the weight amount of the at least one metal salt.

In some embodiments, in a formulation of the invention, the weight amount of VAE or a derivative thereof is smaller than the weight amount of the at least one metal salt.

In some embodiments, the weight ratio between VAE or a derivative thereof and the metal salt may be between 30:1 to 1:1 (VAE or derivative : metal salt). In some embodiments, the weight ratio is any one of 20:l, 19:1, 18:1, 17:1, 16:1, 15:1, 14:1, 13:1, 12:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1 2:1 or 1:1.

In some embodiments, the weight ratio is as listed in Table 1.

In some embodiments, the weight ratio is 6.5:0.5, 6.5:2, 7:0.6, 1:1, 9:0.3, 9:1, 8.2: 1.5, or 9:2 (VAE or derivative: metal salt).

Where the fixation agent is different from a metal salt, the amount of the fixation agent may be between 0.1 and 20 wt%, 1 and 20 wt%, 1 and 15 wt%, 1 and 10 wt%, 3 and 20 wt%, 3 and 15 wt%, 3 and 10 wt%, 4 and 10 wt%, 5 and 10 wt%, 6 and 10 wt%, 7 and 10 wt%, 8 and 10 wt%, 2 and 15 wt%, 3 and 15 wt%, 4 and 15 wt%, 5 and 15 wt%,

6 and 15 wt%, 7 and 15 wt%, 8 and 15 wt%, 9 and 15 wt%, 5 and 20 wt%, 6 and 20 wt%,

7 and 20 wt%, 8 and 20 wt%, or 9 and 20 wt%. In some embodiments, the amount of the fixation agent, being different from the at least one metal salt is between 0.3 and 20 wt%, 0.3 and 10 wt%, 0.4 and 20 wt%, 0.4 and 10 wt%, 0.5 and 20 wt%, 0.5 and 10 wt%, 0.5 and 5 wt%, or between 0.1 and 1 wt%.

As noted herein, the “ratio” VAE or derivative: metal salt refers to the relative amount of VAE or derivative vs metal salt in a formulation of the invention. The ratio may be expressed also in wt% values. Where a ratio of e.g., 1:1 is mentioned, it encompasses any ratio between l±10%:l and 1:1+10%. In other words, a ratio of 1:1 encompasses ratios between 0.9 to 1.1 :0.9 to 1.1. Similarly, as yet another example, a ratio of 5:1 encompasses ratios between 5+10%:l+10%, namely a ratio of 4.5 : 1.1.

In some embodiments, a pretreatment formulation comprises VA-E-NMA.

In some embodiments, a pretreatment formulation comprises VAE and/or VA-E- NMA and a calcium-based salt, such as calcium chloride.

In some embodiments, the formulation comprises a VAE derivative, as defined herein, in combination with poly(diallyldimethylammonium chloride and CaCh, wherein optionally the VAE derivative: poly(diallyldimethylammonium chloride: CaCh is between 3: 1.1:6 and 4.5: 1.7:9.

In some embodiments, the formulation comprises a VAE derivative, as defined herein, in combination with CaCh, optionally at a ratio VAE derivative: CaCh of 4:0.5, 7.5:0.9 or 7.5:15.

As disclosed hereinabove, ink-sets of the invention comprise a pretreatment formulation and an ink formulation. The ink-sets may be adapted to be printed in sequence, such that the pretreatment formulation is printed or applied or used to form a dry film or coat of predefined properties on a substrate material, onto which the ink formulation is printed. Thus, pretreatment formulations are used for forming ink-sets further comprising an ink formulation.

Irrespective of whether the pretreatment formulation is provided separately from the ink formulation or within a same commercial package, kit or ink- set, application of the pretreatment formulation may proceed on any substrate on the surface of which subsequent ink printing is intended or desired. The pretreatment formulations of the invention are configured and selected to define a receptive surface by way of a receptive film or coat on a substrate which may be a fabric, a plastic or a polymeric material or any material comprising same. More specifically, the substrate may be any substrate selected, in some embodiments, from absorptive or non-absorptive materials, natural or synthetic materials (e.g., fabrics and textiles), paper materials (e.g., paper, paperboard, wallpaper), polymeric materials (e.g., made from a polyester, a polyethylene, a polypropylene, vinyl and acrylic, PVC, leather, metal, wood, corrugated plastic signs, plasticized nylon and blends thereof) and others. While application of a pretreatment formulation may be generic to all types of surfaces, it may be more selective towards textile and fabric substrates. Such textile and fabric substrates may be a woven or a non-woven textile material, which may or may not be formed of a natural fiber, a synthetic fiber, or a combination of the two. Non-limiting examples of textiles and fabrics include such comprised of or formed of polyester fibers, polyurethane fibers, polyethylene fibers, polyamide fibers, polyacryl fibers, polybenzimidazole fibers, Nylon, Dacron fibers, Modacryl fibers, Rayon fibers, Viscose Rayon fibers, acetate fibers, Saran fibers, Spandex fibers, Vinalon fibers, Aramid fibers, Elastane fibers, cellulose fibers, linen fibers, Flax fibers, Hemp fibers, silk fibers, wool fibers and others.

The pretreatment formulation may be applied non- selectively on the substrate, to e.g., cover the full surface of the substrate or to cover regions larger than those intended for ink printing; or selectively, in which case the pretreatment formulation may be of substantially the same shape and size of the ink pattern which it is intended to receive. As the pretreatment formulation can also endow better and improved mechanical properties to the substrate, mainly a fabric or a textile, such that prolong the life span of the printed product, increases its flexibility, strengthens its initial adhesion, creep-resistance, and boosts its durability (e.g., water and solvent- resistance) that leads to improved washfastness, in some cases, it may be desirable to non-selectively coat the whole surface of the fabric, or at least a larger region than intended for printing.

Following surface application by any means known in the art, such as brushing, spraying, printing, via use of a pretreat machine, etc., thermal drying or curing may be required to solidify the formed pattern or coat and endow it with the intended properties. Thermal treatment may typically involve heating the formed pattern at temperatures below an activating temperature of a latent acid or a base (the temperature at which the latent acid or base converts into the corresponding acid or base, respectively), where present. In some embodiments, the temperature is thus above 100°C, or above 120°C, or above 130°C, or above 150°C, or above 170°C, or between 130 and 150°C, or between 150 and 180°C. The cured and dry surface may receive an ink formulation by any means and methods known in the art. While common ink printing methods include digital printing, such as inkjet printing may be typically used (i.e., direct to garment (DTG), and roll-to- roll for textile and fabric substrates), transfer printing processes, flexo, roto gravure, direct to film (DTF), offset and screen printing may be similarly used. The ink formulation may be applied onto any part of the pretreated surface region. Application may proceed wet- on-dry, whereby the pretreatment formulation is first allowed to dry or cure.

Following application of the ink formulation, the pattern may be thermally treated at a temperature that is above an activating temperature of a latent acid or base which may be present. Thus, the temperature may be above 90°C or above 105°C or above 110°C or above 120°C, or above 130°C, or above 150°C, or between 130 and 150°C, or between 150 and 180°C to e.g., cause activation of a latent acid or a latent base, releasing an acid or base, respectively. The released acid or base may catalyze the self-crosslinking reaction described hereinabove, leading to a faster and more efficient self-crosslinking of the VAE derivative of the invention.

The invention further provides a method of forming an ink pattern on a surface, as defined, the method comprising coating a surface region of a substrate (or forming a coat of a film) with a pretreatment formulation according to the invention and patterning an ink formulation on at least a region of the pretreated surface region, wherein the region may be a dry region, a wet region or a partially wet (partially dry) region.

In some embodiments, the region of the pretreated surface region is dried before application of the ink formulation.

Further, the invention provides a method of forming an ink pattern on a recipient surface present on a textile substrate, the method comprising obtaining a textile substrate having a part or all of its surface coated with a pretreatment formulation according to the invention and patterning an ink formulation on at least a dry /cured portion of the surface region.

Also provided is a method of forming a pattern on a dry or cured surface region of a recipient coat or film of a pretreatment formulation, wherein the forming comprises digital printing, the method comprises forming an ink pattern on a pretreated surface region of a substrate (namely a surface region having a recipient layer of a pretreatment formulation of the invention) with an ink formulation, wherein the ink pattern covers the full surface of the pretreated surface region or a part thereof. The invention further provides a method of applying a wet ink formulation onto a region of a dry or cured film or coat of a pretreatment formulation, the method comprising -obtaining a pretreatment formulation according to the invention;

-forming a film or coat of said formulation onto a surface of a substrate;

-drying or curing said film or coat, e.g., under thermal radiation or heat; and

-applying a wet ink formulation on a region of said dried or cured film or coat.

The process further comprises a step of drying or curing the ink formulation applied onto the region of the dried or cured film or coat.

In some embodiments, a formulation of the invention comprises

(i) at least one metal salt, as defined herein, wherein optionally the metal salt is selected from calcium salts, such as CaCh, CaF2, CaBn, CaAc2, or Cah, wherein the amount of the salt does not exceed 20 wt% or is between 0.1 and 20wt% and/or at least other ink fixation agent, as defined herein;

(ii) VAE and/or a VAE derivative, as defined herein, in an amount ranging between 0.1 and 20 wt%; and

(iii) an aqueous carrier.

In some embodiments, a formulation comprises at least one additive, as defined herein.

In some embodiments, the pretreatment formulation is patterned by a means selected from digital printing, direct to garment (DTG), roll-to-roll, transfer printing processes, flexo, roto gravure, direct to film (DTF), offset and screen printing.

In some embodiments, the pretreated surface may receive any ink for forming a pattern or an image. The inks may be selected, for example, from reactive inks, acid inks, disperse inks, sublimation inks, pigment-based inks, dye-based inks, or a combination of dye(s) and pigment(s) inks, and others, as further detailed herein. In some embodiments, the ink formulation suitable for use in combination with a pretreatment of the invention is one that is free of aromatic esters or cyclic esters.

As noted herein, the dry pretreatment film or coat provides a suitable substrate onto which an ink formulation may be applied, by means of a “wet-on-dry” application. The nature and method of applying the ink formulation is outside the scope disclosed herein. Furthermore, the invention provides a method for digital inkjet printing of a color pattern on a recipient film or coat formed from a pretreatment formulation of the invention, the method being any method according to the invention.

The invention further provides a dried or cured pattern or coat or film formed on a substrate, such as a textile, of a formulation according to the invention.

Depending on the selection of VAE and/or the VAE derivative used, the pattern may be in a form of uncross-linked or partially cross-linked form, or a cross-linked dry pattern.

In some embodiments, the pattern is formed on a textile.

Further provided is a dyed or a non-dyed substrate having a film or a pattern of an ink formed on a dried or cured receptive film or pattern afforded by applying a formulation according to the invention on the surface of the substrate.

While the nature and method of applying the ink formulation onto the receptive film or coat formed according to the invention is outside the scope of the invention disclosed herein, the artisan would appreciate that any ink formulation may be used to form a pattern on a cured or dry or non-crosslinked or crosslinked (partially crosslinked or fully crosslinked) or otherwise solid film or coat formed from a pretreatment formulation of the invention. Such inks may be water-based inks or may be selected amongst reactive inks, acid inks, disperse inks, sublimation inks, pigment-based inks, dye-based inks, or a combination of dye(s) and pigment(s) inks, and others, as known in the art.

For some uses, the ink may comprise a self-crosslinkable material or resin, selected, for example, amongst low temperature self-crosslinkable materials or resins. Alternatively, the ink may not comprise crosslinkable materials or resins. The ink formulation may comprise crosslinkable or self-cros slinkable urethane or acrylic-based resins of a variety of compositions and molecular weights. Such materials or resins may be selected amongst the TAKELAC WS- materials from Mitsui Chemicals. These include without limitation TAKELAC WS-6021, TAKELAC WS-5000, WS-5100, WS-4000, WS-4022 and others.

Generally speaking, an ink formulation may also or alternatively include any material typically used in ink formulations. Such materials may include:

-At least one binder such as resins optionally selected from Mitsui Chemicals (TAKELAC WS- or W-materials. These include without limitation TAKELAC W-5661, TAKELAC W-6110, TAKELAC W-5030, TAKELAC W-6355, TAKELAC W-6061, TAKELAC WS-6021, TAKELAC WS-5000, WS-5100, WS-4000, WS-4022, TAKELAC WPB341A), Alberdingk Boley (U400N, U475, U 3200 VP, U5201), Covestro (Impranil 1069) and others;

-At least one humectant such as ethylene glycol (EG), glycerin, propylene glycol (PG). Additional examples include dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, propylene glycol n-butyl ether, propylene glycol n-propyl ether, ethylene glycol hexyl ether, ethylene glycol propyl ether, diethylene glycol phenyl ether, and ethylene glycol phenyl ether;

-At least one wetting and dispersing additive selected amongst ALTANA-BYK (Disperbyk-2018, Disperbyk-2019, Disperbyk-2010, BYK 348, BYK LP N 25015, BYK LP N 25375, BYK-3420, DYNWET 800), Evonik (Dynol 360), and others;

-At least one pigment dispersion such as KODAK (Magenta Dispersion Type A3, Cyan Dispersion Type Al, Yellow Dispersion Type Al, Black Dispersion Type Al), Lubrizol (D71K, D75K, D75C, D75M, D75Y), Fujifilm (PRO-JET Black APD 1000, PRO-JET Cyan APD 1000, PRO-JET Magenta APD 1000, PRO-JET Yellow APD 1000LF, Yellow APD 1000TP), Clariant (Hostajet Black O-PT, Hostajet Cyan BG-PT, Hostajet Yellow 4G-PT, Hostajet Magenta E5B-PT).

The invention provides the following:

A pretreatment formulation comprising at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative, the formulation being free of a pigment or a dye.

A formulation for use in forming a recipient surface for ink application, wherein the formulation comprises at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative, the formulation being free of a pigment or a dye.

A formulation for digital inkjet printing, the formulation comprising or consisting at least one ink fixation agent, at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative and an aqueous carrier, the formulation being free of a pigment or a dye.

An ink-set comprising a pretreatment formulation and an ink formulation, wherein the pretreatment formulation comprises at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative, and wherein the ink formulation comprises a pigment and/or a dye and is free from at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative.

In some embodiments of any formulation of the invention, the formulation is configured and adapted for use with an ink formulation free of a combination of a fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative; or for use with an ink formulation that is free of at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative.

In some embodiments of any formulation of the invention, the pretreatment formulation comprises a carrier and optionally at least one additive selected from a defoamer, a softener, a latent acid, a latent base, a preservative, a biocide, a dispersing agent, a wetting agent and a surfactant.

In some embodiments of any formulation of the invention, the formulation consisting at least one fixation agent, at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative, a carrier and optionally at least one additive.

In some embodiments of any formulation of the invention, the at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative is provided as a single material or as a mixture of two or more materials, as an aqueous dispersion, as a powder, or as an emulsion.

In some embodiments of any formulation of the invention, the VAE or VAE derivative is provided in combination with at least one surfactant.

In some embodiments of any formulation of the invention, the VAE is a copolymerization product of vinyl acetate and ethylene, having vinyl acetate content between 60 and 95%, and ethylene content between 5 and 40% (w/w).

In some embodiments of any formulation of the invention, VAE has a vinyl acetate fraction (w/w) that is at least 60%, or is between 60 and 95%, or between 60 and 90%, or between 60 and 85%, or between 60 and 80%, or between 60 and 75%.

In some embodiments of any formulation of the invention, the fraction (w/w) of the ethylene in the VAE is 5%, or between 5 and 40%, or between 5 and 35%, or between 5 and 30%, or between 5 and 25%, or between 5 and 20%, or between 5 and 15%.

In some embodiments of any formulation of the invention, the VAE derivative is a chemically modified VAE, wherein -a further monomer is introduced along the VAE chain, wherein said monomer is one or more different or same monomers that are each different from VA and E and which optionally comprise a functionality permitting crosslinking, as defined herein; or

-at least a portion or all of the vinyl acetate monomers and/or at least a portion or all of the ethylene monomers are chemically functionalized; or

-at least a portion or all of the vinyl acetate monomers are chemically functionalized, and none of the ethylene monomers are chemically functionalized; or

-none of the vinyl acetate monomers are chemically functionalized, and a plurality or all of the ethylene monomers are chemically functionalized; or wherein

-the backbone of a VAE polymer is chemically functionalized.

In some embodiments of any formulation of the invention, the VAE derivative is a copolymer of vinyl acetate, ethylene and an N-methylol-based compound.

In some embodiments of any formulation of the invention, the VAE derivative is a self-crosslinkable polymer having one or more crosslinkable functionalities.

In some embodiments of any formulation of the invention, the one or more crosslinkable functionalities are selected to inter-molecularaly self-crosslink.

In some embodiments of any formulation of the invention, the one or more crosslinkable functionalities are selected from alcohols, amines, vinyl groups, carboxyl groups, and silanols.

In some embodiments of any formulation of the invention, the VAE derivative is a copolymerization product of vinyl acetate (VA) monomers with N-methylol- functionalized ethylene monomers (or additionally with ethylene monomers (E), which are not functionalized).

In some embodiments of any formulation of the invention, the N-methylol- functionalized ethylene monomer is derived from N-methylol-acrylamide (NMA), N- methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N- methylol maleinamic acid esters, or N-methylol amide of vinyl aromatic acids.

In some embodiments of any formulation of the invention, the N-methylol- functionalized ethylene monomer is an N-methylol-acrylamide (NMA).

In some embodiments of any formulation of the invention, the VAE derivative is a copolymerization product of ethylene (E) monomers with N-methylol-functionalized vinyl acetate monomers. In some embodiments of any formulation of the invention, the N-methylol- functionalized vinyl acetate monomer is derived from N-methylol-acrylamide (NMA), N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N- methylol maleinamic acid esters, or N-methylol amide of vinyl aromatic acids.

In some embodiments of any formulation of the invention, the ink fixation agent is selected for limiting or diminishing ink bleeding.

In some embodiments of any formulation of the invention, the ink fixation agent is at least one cationic material.

In some embodiments of any formulation of the invention, the cationic material is a salt of a metal or of an organic material or a polymeric material.

In some embodiments of any formulation of the invention, the ink fixation agent is selected from metal salts, diamine salts, triamine salts, quaternary ammonium salts, sulfonium salts and phosphonium salts.

In some embodiments of any formulation of the invention, the ink fixation agent is an ammonium salt selected from a polyethyleneimine salt, a polyvinyl amine salt, a polyallyl amine salt, a polydimethyl aminoethyl methacrylate quaternary salt, a polydiallyl dimethyl ammonium salt, a diallylamine acrylic amide copolymer salt, and a quaternary ammonium salt of polystyrene.

In some embodiments of any formulation of the invention, the ink fixation agent is a polyquatemary ammonium salt.

In some embodiments of any formulation of the invention, the polyquatemary ammonium salt is selected from polidronium chloride, poly[bis(2-chloroethyl) ether-alt- l,3-bis[3-(dimethylamino)propyl]urea] quatemized, poly(diallyldimethylammonium chloride), poly(acrylamide-co-diallyldimethylammonium chloride) and nonanediamide N,N'-bis(3-(dimethylamino)propyl)- polymer with l,l'-oxybis(2-chloroethane).

In some embodiments of any formulation of the invention, the ink fixation agent is a polydiallyl dimethyl ammonium salt.

In some embodiments of any formulation of the invention, the salt is poly (diallyldimethylammonium chloride) .

In some embodiments of any formulation of the invention, the ink fixation agent is a sulfonium salt. In some embodiments of any formulation of the invention, the sulfonium salt is selected from poly(4-vinylbenzyltetrahydrothiophenium tetrafluorob orate) and polyphydroxy sulfonium tetrafluoroborate).

In some embodiments of any formulation of the invention, the ink fixation agent is a phosphonium salt.

In some embodiments of any formulation of the invention, the phosphonium salt is selected from poly [tributyl(4-vinylbenzyl)phosphonium salt] and poly(glyceryl methacrylate bis-tributylphosphonium chloride).

In some embodiments of any formulation of the invention, the ink fixation agent is provided as a cationic copolymer or cationic homopolymer.

In some embodiments of any formulation of the invention, the ink fixation agent is a mixture of two or more different ink fixation agents, one of which being optionally a metal salt.

In some embodiments of any formulation of the invention, the at least one ink fixation agent is a metal salt.

In some embodiments of any formulation of the invention, the metal salt is selected from monovalent metal salts, divalent metal salts, trivalent metal salts and combinations thereof.

In some embodiments of any formulation of the invention, the metal is sodium, calcium, aluminum, copper, zinc, cobalt, nickel, or magnesium.

In some embodiments of any formulation of the invention, the counter ion is an inorganic anion or an organic anion.

In some embodiments of any formulation of the invention, the metal salt is at least one inorganic salt having an inorganic anion selected from a chloride, a fluoride, a bromide, an iodide, a nitride, a sulfate, or phosphate anion.

In some embodiments of any formulation of the invention, the metal salt of monovalent cations is selected from lithium chloride, lithium acetate, lithium carbonate, lithium nitrate, lithium phosphate, sodium chloride, sodium acetate, sodium carbonate, sodium nitrate, sodium phosphate, potassium acetate, potassium chloride, potassium carbonate, potassium phosphate, potassium nitrate, copper nitride, copper sulfate, silver chloride, silver nitride, silver sulfate, silver acetate, silver citrate, silver propionate, silver phosphate, gold chloride, gold nitride, gold sulfate, gold acetate, gold citrate, gold propionate, and gold phosphate. In some embodiments of any formulation of the invention, the metal salt of divalent cations is selected from magnesium chloride, magnesium acetate, magnesium carbonate, magnesium nitrate, magnesium phosphate, calcium chloride, calcium acetate, calcium carbonate, calcium nitrate, calcium nitrate, calcium phosphate, zinc chloride, zinc acetate, zinc carbonate, zinc nitrate, zinc phosphate, copper chloride, copper acetate, copper carbonate, copper nitrate, copper phosphate, tin chloride, tin acetate, tin carbonate, tin nitrate, tin phosphate, ferrous chloride, ferrous acetate, ferrous carbonate, ferrous nitrate, ferrous phosphate, and combinations thereof.

In some embodiments of any formulation of the invention, the at least one fixation agent is a calcium salt, optionally selected from CaC12, CaF2, CaBr2, CaI2, calcium carbonate, calcium acetate, CalBr, and CaCIBr.

In some embodiments of any formulation of the invention, the formulation comprising between 0.1 and 20 wt% of VAE or a derivative thereof.

In some embodiments of any formulation of the invention, the formulation comprising between 0.1 and 20 wt% of fixation agent.

In some embodiments of any formulation of the invention, the weight amount of VAE or a derivative thereof is optionally greater than the weight amount of the at least one fixation agent.

A method of forming an ink pattern on a surface, the method comprising coating a surface region of a substrate (or forming a coat or a film) with a pretreatment formulation according to the invention and patterning an ink formulation on at least one region of the surface region of the substrate coated with the pretreatment formulation, wherein the at least one region coated with the pretreatment formulation is a dry or a wet region.

A method of forming an ink pattern on a dry or wet recipient surface present on a textile substrate, the method comprising obtaining a textile substrate having a part of its surface region or the complete surface region coated with a pretreatment formulation according to the invention, and forming a pattern of an ink formulation on at least a portion of the surface region coated with the pretreatment formulation, wherein optionally prior to the forming of the ink pattern the coated region is dried to obtain a dry recipient surface.

A method of forming a pattern on a dry or cured surface region of a recipient coat or film of a pretreatment formulation according to the invention, wherein the forming comprises digital printing, the method comprises forming an ink pattern on a pretreated surface region of a substrate with an ink formulation, wherein the ink pattern covers the full surface region of the pretreated surface region or a part thereof.

A method of applying a wet ink formulation onto a region of a dry or cured film or coat of a pretreatment formulation, the method comprising

-obtaining a pretreatment formulation according to the invention;

-forming a film or a coat of said pretreatment formulation onto a surface of a substrate;

-drying or curing said film or coat; and

-applying a wet ink formulation on a region of said cured film or coat.

In some embodiments of any method of the invention, the method comprising drying or curing the ink formulation applied onto the region of the dried or cured film or coat.

In some embodiments of any method of the invention, the pretreatment formulation comprises at least one metal salt optionally selected from calcium acetate, CaCh, CaF2, CaBn, or Cab, wherein the amount of the salt does not exceed 20 wt% or is between 0.1 and 20wt%; VAE and/or a VAE derivative in an amount ranging between 0.1 and 20 wt%; and an aqueous carrier.

In some embodiments of any method of the invention, the pretreatment formulation further comprises poly (diallyldimethylammonium chloride).

In some embodiments of any method of the invention, the pretreatment formulation comprises poly(diallyldimethylammonium chloride); VAE and/or a VAE derivative; an aqueous carrier and optionally a metal salt.

In some embodiments of any method of the invention, the pretreatment formulation is patterned by digital printing, direct to garment (DTG), roll-to-roll, transfer printing processes, flexo, roto gravure, direct to film (DTF), offset, screen printing, brushing or spraying.

In some embodiments of any method of the invention, the ink formulation is applied or patterned by inkjet.

A dried or cured pattern or coat or film formed on a substrate, the film being formed of a formulation or a method according to the invention. In some embodiments of any film of the invention, the film is formed on substrate selected from absorptive or non- absorptive materials, natural or synthetic materials, paper materials, polymeric materials.

In some embodiments of any film of the invention, the film is formed on a textile or a fabric substrate selected from polyester fibers, polyurethane fibers, polyethylene fibers, polyamide fibers, polyacryl fibers, polybenzimidazole fibers, Nylon, Dacron fibers, Modacryl fibers, Rayon fibers, Viscose Rayon fibers, acetate fibers, Saran fibers, Spandex fibers, Vinalon fibers, Aramid fibers, Elastane fibers, cellulose fibers, linen fibers, Flax fibers, Hemp fibers, silk fibers, and wool fibers.

A fabric coated with a dry or wet film of a pretreatment formulation comprising VAE and/or a VAE derivative, and at least one ink fixation agent, wherein:

-when the film is a wet film, the film further comprises water; and

-when the film is a dry film, the film is (substantially) free of water.

A fabric coated with a dry film of a pretreatment formulation comprising VAE and/or a VAE derivative, and at least one ink fixation agent, wherein said dry film is overlayed with an ink film or an ink pattern.

In some embodiments of any product of the invention, the at least one fixation agent is a metal salt and/or a salt selected from ammonium, sulfonium and phosphonium salts.

DETAILED DESCRIPTION OF EMBODIMENTS

Exemplary formulations according to embodiments of the present invention:

Various VAE-based pretreatment formulations have been prepared and utilized on a variety of surfaces, such as fabrics. Formulations comprising VAE and/or a VAE derivative, as defined and selected herein, have demonstrated efficient formation of robust solid films and coats that could be used as effective recipient layers of ink-based formulations.

In the data below, data relating to exemplary formulations is provided. Generally, VAE derivatives tested include derivatives regraded herein as copolymers of VA and E, wherein either one or both of VA and E is derivatized or functionalized with an N- methylol derived from N-methy lol- acrylamide (NMA), N-methylol methacrylamide, N- methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid eater, or N-methylol amide of vinyl aromatic acids (or additionally with VA monomers and/or E monomers, which are not functionalized).

In some cases, the VAE derivative is a copolymer of VA with E functionalized with N-methylol derived from NMA (or additionally with ethylene monomers (E) which are not functionalized).

Table 1 demonstrates use of a copolymer of VA and/or and E with E- or VA- functionalized with N-methylol derived from NMA according to the invention, when implemented in several non-limiting pretreatment formulations. Each of these formulations may be used to form a precoat or a recipient coat on a fabric or a polymeric substrate to enable subsequent printing or patterning by an ink formulation. The carrier for all formulations was water. Additives were added or were excluded, depending on the particular intended use.

Table 1: Exemplary formulations according to some embodiments of the invention

* the copolymer of VA, E and E-functionalized with N-methylol derived from NMA may be synthetically made or commercially obtained from a variety of sources such as Celanese under Vinamul and Mowilith series, and Wacker Chemie AG under the VINNAPAS series.

The above formulations, when applied on a substrate such as a fabric, demonstrated excellent hand feel and exhibited no ink bleeding or ink smearing when printed on.

Application of a pretreatment formulation:

A T-shirt, cotton or polyester, was treated with a pretreatment formulation via use of an automatic pretreatment machine (Schulze PRETREATmaker IV). Subsequent to the application of the formulation onto the shirt, thermal energy was applied via hot air dryer or a heat press to cause drying or curing of the coating.

Following the formation of a dry pretreatment coat on the T-shirt, an inkjet DTG (direct to garment) printer was used to print an image onto the pretreated T-shirt. Thermal energy was again applied to accomplish drying or curing of the ink pattern by utilizing a hot air dryer or a heat press.

This process was repeated, mutatis mutandis, on a variety of other textiles, polymeric substrates and other substrate materials as disclosed herein.

The ink formulation used for patterning on top of the pretreatment coat was an aqueous pigmented ink having the composition provided in Table 2. Table 2: Exemplary ink formulation used in testing durability of a pretreatment formulation of the invention

Other ink formulations may be used in place of that in Table 2.

Stability and mechanical properties of the dried and or cured image printed on the pretreated fabric substrate:

To test the durability of the pattern formed on the pretreatment coating, the T-shirt was washed in a washing machine numerous times beginning on the day following printing. A wash-fastness test was conducted to evaluate water and detergent resistance, the ability to withstand different pH and temperature conditions, as well as rub resistance.

Further, a color fade wash-resistance test was conducted with a standard household laundry machine (LAVAMAT LVW9140T). Twenty wash cycles (1000 rpm, at 30°C using day-to-day 60 minutes wash mode) were carried throughout the test, every 5 sequential cycles the entire full load was dried on a drying stand. This process was repeated 4 times.

Table 3 depicts wash-fastness results onto different type of T-shirt substrates with having applied the various pretreatment formulations of Table 1. The data herein reflects the outcome of separate multiple tests, all involving different formulations, yet same or substantially same surface application, drying or curing processes of the substrate prior and post printing (e.g., via a heat press - Stahls Hotronix Air Fusion Heat Press), while using the conditions listed in Table 3, followed by a color fade wash-resistance test. Note that the conditions used in the Table may be varied based on the substate use, the test conditions and the type of mechanical durability that is investigated. Table 3: Test conditions

Results and Discussion:

Generally, wash-fastness is measured via sequential or non-sequential set number of laundry cycles. The resistance of a material to change in any of its colors characteristics is evaluated while stimulating rubbing-fastness, withstanding changes in pH and temperature parameters and exposing to water and detergent. The grades range between 1 and 5, while the lowest rank is 1 and the highest 5. Manufacturers target a minimum of grade 3, but usually aim for a grade equal to or above 4.

As noted herein, pretreating of a substrate with formulations of the invention resulted in high wash-fastness ranking scores, ranging between 4 and 4.5. This stands to show that the pretreatment allows an enhanced resistance to external forces, reflecting on the bonding of the substrate-pretreatment-ink formulations as well as on the robust physical and chemical properties of the pretreatment film/coat applied onto the substrate and resulted from the self-crosslinking of the VAE derivative used.