[0001] The present invention relates to mineral fibre products, notably non-woven mineral fibre veils, mineral wool insulation, glass wool insulation and stone wool insulation, to a method for their production, and particularly to curable binder compositions for these products.

[0002] The mineral wool industry has historically used phenol formaldehyde binders, particularly urea extended phenol formaldehyde binders, to bind mineral wool fibres. Phenol formaldehyde type binders provide a desirable combination of properties; however, environmental considerations have motivated the development of alternative binders, notably binders referred to as no added formaldehyde binders because these binders do not utilize formaldehyde as a reagent. For example non phenol formaldehyde binders are disclosed in the following patent applications: WO03/104284 discloses binders comprising the reaction products of an epoxide and an epoxide crosslinking agent; W02005/087837 discloses binders comprising the esterification products of reacting a polycarboxylic acid and a polyol; WO2012/118939 discloses binders comprising esterification products of carbohydrates and polycarboxylic acids; W02004/007615 discloses binder comprising reacting carbohydrate with reaction products of alkanolamine and carboxylic anhydride; WO 2007/014236 discloses carbohydrate based binder that comprises a Maillard reaction product, notably a carbohydrate based binder derived from reacting a reducing sugar, a carboxylic acid and ammonia; WO 2009/019235 discloses carbohydrate based binder derived from reacting a reducing sugar and an acid precursor derived from an inorganic salt, in particular an ammonium salt; WO2012/072938 discloses binders derived from reacting non-reducing sugars and inorganic-acid ammonium salts.

[0003] Despite the numerous propositions for and the benefits of no added formaldehyde binders, urea extended phenol formaldehyde binders are still the industry standard binders for mineral wool insulation. Consequently, it would be desirable to make further improvements in no added formaldehyde binder compositions to provide a desirable combination of properties that would lead to wider use.

[0004] In accordance with one aspect, the present invention provides a method of manufacturing a mineral fibre product selected from a non-woven mineral fibre veil, mineral wool insulation, glass wool insulation and stone wool insulation, the method comprising:

- applying an aqueous, curable binder composition to non or loosely assembled mineral fibres to provide resinated mineral fibres; and

- subjecting the resinated mineral fibres to heat to cure the aqueous, curable binder composition and to form the mineral fibre product ;

- wherein the aqueous, curable binder composition applied to the mineral fibres comprises:

1) reducing sugar(s),

2) inorganic ammonium salt(s),

3) oxirane-containing reactant(s) comprising at least two oxirane groups; and

4) optional additive(s), notably silane coupling agent(s) and wherein when (a) represents the total dry weight of the reducing sugar(s), (b) represents the total dry weight of the inorganic ammonium salt(s), and (c) represents the total dry weight of the oxirane- containing reactant(s),

(a) + (b) + (c) is at least 90 wt% of the total dry weight of the aqueous, curable binder composition;

(a) is 55 to 90 wt % of the total dry weight of (a), (b) and (c);

(b) is at least 1 wt % of the total dry weight of (a), (b) and (c); and

(c) is at least 1 wt % of the total dry weight of (a), (b) and (c).

[0005] The present invention provides binder compositions with properties including excellent curing rates, bond strength, parting strength, tensile strength and low swelling properties, ease of handling and good storage stability. Surprisingly, it has been found that the use of these binder compositions provides good resistance to ageing in humid environment. Notably, the present aqueous, curable binder composition provides the desirable bond strength and fire resistance properties of mineral fibre product obtained with aqueous, curable binder composition in accordance with WO 2009/019235 while providing unexpectedly improved ageing resistance in humid environments and good anti-punking properties; this is achieved with the defined low quantity of oxirane-containing reactant(s). One of the benefits of the present invention is an ability to provide such a binder composition which comprises a high proportion of renewable and/ or readily available raw materials.

[0006] The non or loosely assembled mineral fibres matter may comprise woven or non-woven fibre material. The mineral fibres may be selected from stone wool fibres, glass fibres and combinations thereof.

[0007] The mineral fibre product may be mineral fibre insulation product, for example glass wool insulation or stone wool insulation. The mineral fibre products may be mineral fibre veil, e.g. a glass fibre veil, which may then find application for example in battery separators, as substrate for roofing products such as roofing membranes or shingles, or other membranes.

[0008] Any feature described herein in relation to a particular aspect of the invention may be used in relation to any other aspect of the invention.

[0009] The term “aqueous, curable binder composition” as used herein means all binder ingredients applied to the non or loosely assembled mineral fibres and/or present on the non or loosely assembled mineral fibres, notably prior to curing, (other than the non or loosely assembled mineral fibres itself and any moisture in the non or loosely assembled mineral fibres), including reactants, solvents (including water) and additives. The term “dry weight of the aqueous, curable binder composition” as used herein means the weight of all components of the aqueous, curable binder composition other than any water that is present (whether in the form of liquid water or in the form of water of crystallization).

[0010] The aqueous, curable binder composition applied to the non or loosely assembled mineral fibres comprises reactants which cross-link when cured to form a cured binder which holds the non or loosely assembled matter together to form the mineral fibre product. The aqueous, curable binder composition comprises reactants that will preferably form a thermoset resin upon curing. The cured aqueous, curable binder composition is preferably a thermoset resin. The reactants of the aqueous, curable binder composition comprise, preferably consist essentially of, and more preferably consist of 1) the reducing sugar(s), 2) the inorganic ammonium salt(s), and 3) the oxirane-containing reactant(s). [0011] The aqueous, curable binder composition is preferably a “no added formaldehyde binder”, that is to say that it does not comprise formaldehyde as a binder reagent. It may be substantially formaldehyde free; as used herein the term “substantially formaldehyde free” means that the aqueous, curable binder composition liberates less than 5 ppm formaldehyde as a result of drying and/or curing (or appropriate tests simulating drying and/or curing); more preferably it is formaldehyde free, as used herein the term “formaldehyde free” means that the aqueous, curable binder composition liberates less than 1 ppm formaldehyde in such conditions.

[0012] Preferably, the aqueous, curable binder composition is a reducing sugar based binder composition; as used herein the term “reducing sugar based binder composition” means that the aqueous, curable binder composition comprises at least 50 wt% of reducing sugar(s) by dry weight based on the total dry weight of the aqueous, curable binder composition.

[0013] As used herein, the term "consist or consisting essentially of is intended to limit the scope of a statement or claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic(s) of the invention.

[0014] The reducing sugar(s) may comprise: a monosaccharide, a monosaccharide in its aldose or ketose form, a disaccharide, a polysaccharide, a triose, a tetrose, a pentose, xylose, a hexose, dextrose, fructose, a heptose, or mixtures thereof. The reducing sugar(s) may comprise, consist essentially of, or consist of a combination of dextrose and fructose, for example in which the combination of dextrose and fructose makes up at least 80 wt% of the reducing sugar(s) and/or in which the dextrose makes up at least 40 wt% of the reducing sugar(s) and/or in which the fructose makes up at least 40 wt% of the reducing sugar(s); the reducing sugar reactant(s) may comprise, consist essentially of, or consist of high fructose corn syrup (HFCS). The reducing sugar reactant(s) may be derived from carbohydrate reactant(s), notably carbohydrate reactant(s) having a dextrose equivalent of at least about 50, at least about 60, at least about 70, at least about 80 or at least about 90, notably carbohydrate reactant(s) selected from the group consisting of molasses, starch, starch hydrolysate, cellulose hydrolysates, and mixtures thereof. The reducing sugar reactant(s) may be derived from hemicellulose. The reducing sugar(s) may be derived from non-reducing sugar(s) that yield the reducing sugar(s) in situ, notably sucrose. The reducing sugar(s) may comprise reducing sugar(s) selected from the group consisting of xylose, arabinose, dextrose, mannose, fructose and combinations thereof, for example making up at least 80 wt% of the reducing sugar(s). The reducing sugar(s) may comprise reducing sugar(s) selected from the group consisting of xylose, arabinose, dextrose, mannose, fructose, galactose and combinations thereof.

[0015] Preferably, the inorganic ammonium salt(s) comprise, more preferably consist essentially of, and most preferably consist of compound(s) selected from the group consisting of ammonium sulfates, ammonium hydrogen sulfate (NH4)HSC>4, ammonium sulfate (NH4)2SC>4, ammonium sulfamate (NH4)SO3NH2, ammonium phosphates, ammonium dihydrogen phosphate (NH4)(H2 C>4), diammonium hydrogen phosphate (NF HPC ), ammonium phosphate (NH^PC , ammonium carbonates, ammonium carbonate (NF CCh), ammonium hydrogen carbonate (NH4XHCO3) and combinations thereof. It is particularly preferred for the inorganic ammonium salt(s) to comprise, more preferably to consist essentially of, and most preferably to consist of diammonium hydrogen phosphate. When introduced into aqueous solutions, the inorganic ammonium salts provide the corresponding ions, for example when introduced into water, ammonium sulfate (NH4XSO4 provides the corresponding ammonium and sulfate ions.

[0016] Alternatively the inorganic ammonium salt(s) may comprise compound(s) selected from ammonium molybdates, notably ammonium hepta molybdate and ammonium dimolybdate, ammonium hexachloroplatinate(IV), ammonium chromate(IV), ammonium tetrafluoroborate, ammonium trioxovanadate(V), ammonium polyphosphate, ammonium phosphomolybdate, ammonium phosphomolybdate hydrate, sodium ammonium hydrogen phosphate tetrahydrate and combinations thereof.

[0017] The oxirane-containing reactant(s) of the present invention comprise at least two oxirane groups.

[0018] Preferably the oxirane-containing reactant(s) comprise, more preferably consist essentially of, and most preferably consist of compound(s) selected from a bisphenol diglycidyl ether, high molecular weight polymers of bisphenol diglycidyl ether and combinations thereof. As illustrated by way of example with bisphenol A, bisphenol A diglycidyl ether (BADGE) corresponds to the compound obtainable by reacting epichlorohydrin with bisphenol A and high molecular weight polymers of bisphenol A diglycidyl ether, as defined herein, are compounds obtainable by the reaction of bisphenol A diglycidyl ether with further bisphenol A. While non limited to these specific examples, the bisphenol may be bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol C2, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol Z, tetrabromobisphenol A or combinations thereof. The high molecular weight polymers of bisphenol diglycidyl ether may comprise, preferably consist essentially of, and more preferably consist of compounds having a molecular weight in the range between 200 Da to 8000 Da, preferably in the range between 300 Da to 6000 Da, more preferably in the range between 400 Da to 3000 Da, and even more preferably in the range between 500 Da to 1500 Da. Preferably, the oxirane- containing reactant(s) comprise, more preferably consist essentially of, and most preferably consist of compound(s) selected from high molecular weight polymers of bisphenol A diglycidyl ether, high molecular weight polymers of bisphenol F diglycidyl ether and combination thereof.

[0019] Alternatively, the oxirane-containing reactant(s) may comprise, consist essentially of, or consist of, epoxy phenol novolac(s). Epoxy phenol novolacs are reactants wherein an oxirane group is attached to the phenolic oxygen of a phenolic novolac. As such, each phenol oxygen of the novolacs is attached with a -CH2-(C2H3O) group, where -(C2H3O) is the three-membered oxirane ring. The epoxy phenol novolacs may comprise, consist essentially of, or consist of compound(s) selected from epoxyphenol novolacs (EPN), epoxycresol novolacs (ECN), and combinations thereof. Preferably, the epoxy phenol novolac(s) comprise between 2 to 6 oxirane groups per molecule.

[0020] Alternatively, the oxirane-containing reactant(s) may comprise, consist essentially of, or consist of, aliphatic oxirane-containing reactants. The aliphatic oxirane-containing reactants may be obtained by epoxidation of double bonds or formed by reaction with epichlorohydrin. The aliphatic oxirane-containing reactants may comprise, consist essentially of, or consist of, cycloaliphatic oxirane- containing reactants.

[0021] Alternatively, the oxirane-containing reactant(s) may comprise, consist essentially of, or consist of, halogenated oxirane-containing reactants. Halogenated oxirane-containing reactants comprise at least one halogen atom. The halogenated oxirane-containing reactants may comprise, consist essentially of, or consist of compound(s) selected from brominated oxirane-containing reactants, fluorinated oxirane-containing reactants and combination thereof. In one preferred embodiment, oxirane-containing reactant(s) comprise brominated oxirane-containing reactants. Without wishing to be bound by theory, it is believed that the presence of halogen atoms, notably bromine, in the oxirane-containing reactants provides good fire retardancy of the mineral fibre product. [0022] Alternatively, the oxirane-containing reactant(s) may comprise, consist essentially of, or consist of compounds known as “epoxy resin diluents”. These “epoxy resin diluents” are obtainable by glycidylation of aliphatic alcohol or polyols and also aromatic alcohols. These oxirane-containing reactant(s) according to the present invention, may be difunctional, i.e. comprising two and only two oxirane groups, for example 1 ,4-butanediol diglycidyl ether (B14DODGE) or diethylene glycol diglycidyl ether (DEGDGE), or higher functionality, i.e. comprising three or more oxirane groups, for example trimethylolpropane triglycidyl ether (TMPTGE) or 4,4'-Methylenebis(N ,N -bis(oxiranylmethyl)aniline). The oxirane-containing reactant(s) may comprise, consist essentially of, or consist of compound(s) selected from B14DODGE, DEGDGE, TMPTGE, 4,4'-Methylenebis[N ,N -bis(oxiranylmethyl)aniline and combinations thereof.

[0023] Alternatively, the oxirane-containing reactant(s) may comprise, consist essentially of, or consist of glycidylamine oxirane-containing reactants. These reactants are obtainable by the reaction of aromatic amines with epichlorohydrin. The glycidylamine oxirane-containing reactants may comprise, consist essentially of, or consist of compound(s) selected from triglycidyl para-aminophenol (TGPAP), triglycidyl of 4-(4-aminophenoxy)phenol (TGAPP), and combination thereof.

[0024] Alternatively, the oxirane-containing reactant(s) may comprise, consist essentially of, or consist of, oxirane-containing reactant(s) derived from natural resources, i.e. oxirane-containing reactant(s) derived or produced from biobased products. Oxirane-containing reactant(s) derived from natural resources may be obtained from natural resources by any method known to obtain an oxirane group, notably by epoxidation of double bonds or by reaction with epichlorohydrin. These oxirane- containing reactant(s) derived from natural resources may be derived from natural, vegetable oils, for example soy bean oil. These oxirane-containing reactant(s) derived from natural resources may notably be derived from any renewable resources, notably lignins, tannins, hemicelluloses, or starch. These oxirane-containing reactant(s) derived from natural resources may be derived from sugars, notably glucose, fructose and sorbose.

[0025] Preferably, the oxirane-containing reactant(s) comprise, more preferably consist essentially of, and most preferably consist of compound(s) having a molecular weight in the range of 100 Da to 8000 Da, preferably in the range of 200 Da to 8000 Da, preferably in the range of 300 Da to 6000 Da, more preferably in the range of 400 Da to 3000 Da, most preferably in the range of 500 Da to 1500 Da. Preferably, the oxirane-containing reactant(s) comprise at least 90 wt% by dry weight, more preferably at least 95 wt% by dry weight of compound(s) having a molecular weight in the range of 200 Da to 8000 Da, preferably in the range of 300 Da to 6000 Da, more preferably in the range of 400 Da to 3000 Da, most preferably in the range of 500 Da to 1500 Da.

[0026] Preferably, the oxirane-containing reactant(s) comprise, more preferably consist essentially of, and most preferably consist of compound(s) having a number average molecular weight in the range of 200 Da to 8000 Da, preferably in the range of 300 Da to 6000 Da, more preferably in the range of 400 Da to 3000 Da, most preferably in the range of 500 Da to 1500 Da.

[0027] The oxirane-containing reactant(s) may be in the form of an emulsion when introduced with the reducing sugar(s) and the inorganic ammonium salt(s) to form the aqueous curable binder composition. The viscosity of the oxirane containing reactant(s) in the form of an emulsion may be in the range of 2 to 1500 cP, of 100 to 1000 cP, of 150 to 800 cP, of 200 to 600 cP when measured using a LV-Torque Brookfield Viscometer, spindle LV-18 at 60 rpm at 20 °C.

[0028] The oxirane-containing reactant(s) preferably comprise, more preferably consist essentially of, and most preferably consist of compounds comprising aromatic rings, notably benzene rings. The presence of aromatics rings, notably benzenic rings, is believed to provide anti-punking and hydrophobic properties when manufacturing mineral fibre products.

[0029] Preferably the oxirane-containing reactant(s) is silicon free, i.e. it does not comprise a silicon atom.

[0030] The aqueous, curable binder composition may be prepared by combining reactants comprising, preferably consisting essentially of, and more preferably consisting of the 1) reducing sugar(s), 2) inorganic ammonium salt(s), and 3) oxirane-containing reactant(s), and 4) optional additive(s), notably an optional silane coupling agent.

[0031] The aqueous curable binder composition may be devoid of organic acids, notably devoid of polycarboxylic acid(s).

[0032] When (a) represents the total dry weight of the reducing sugar(s), (b) represents the total dry weight of the inorganic ammonium salt(s), (c) represents the total dry weight of the oxirane- containing reactant(s),

- (a) represents from 55 wt% to 90 wt%, more preferably from 70 wt% to 90 wt%, more preferably from 75 wt% to 90 wt%, even more preferably from 75 wt% to 85 wt% of the total dry weight of (a), (b) and (c);

- (b) represents from 1 wt% to 25 wt%, preferably from 2.5 wt% to 20 wt%, more preferably from 5 wt% to 20 wt % of the total dry weight of (a), (b) and (c);

- (c) represents from 1 wt% to 35 wt%, preferably from 2.5 wt% to 15 wt%, more preferably from 3 wt% to 10 wt% of the total dry weight of (a), (b) and (c);

- (a) + (b) + (c) is at least 90 wt%, preferably 95 wt%, more preferably at least 97 wt%, even more preferably at least 98 wt% of the total dry weight of the aqueous, curable binder composition.

[0033] The number of equivalents of oxirane groups relative to the number of equivalents of carbonyl (as aldehyde or ketone) groups in the reducing sugar may be in range from 1 :1 to 1 :50, from 1 :1 to 1 :80, or from 1 :1 to 1 :100, preferably in a range from 1 :25 to 1 :100.

[0034] Curing of the aqueous, curable binder composition may comprise Maillard reaction(s). The cured binder composition may comprise melanoidin-containing and/or nitrogenous-containing polymer(s). The cured binder composition is preferably a thermoset binder. The cured binder composition is preferably substantially water insoluble. The cured binder may comprise ester and/or polyester compounds/functions. Curing of the aqueous, curable binder composition may involve condensation reactions, elimination reactions, addition polymerization reactions, and/or ionic interactions, or electrostatic interactions such as hydrogen bonding between one or more of the reactants.

[0035] The aqueous, curable binder composition may comprise 4) optional additive(s), for example one or more additives selected from dedusting oil, waxes, water repellent agent, silanes and silicones. When (d) represents the total dry weight of the optional additive(s), (d) is less than 10 wt%, less than 8 wt%, preferably less than 5 wt%, more preferably less than 3 wt%, of the total dry weight of the aqueous, curable binder composition.

[0036] The optional additive(s) may comprise optional silane coupling agent(s), notably epoxysilane(s) and/or aminosilane(s). When manufacturing mineral fibre products, silane coupling agent(s) are used to enhance the adhesion of the binder composition to the mineral fibres. The silane coupling agent(s) comprise a silane group able to react with silanol groups at a surface of the mineral fibres, and at least one reactive function, notably amine or oxirane able to react with the binder composition. Preferably the optional silane coupling agent(s) (when used) comprise, consist essentially of, or consist of aminosilane(s). The total dry weight of the optional silane coupling agent(s) when used may be less than 2 wt%, preferably less than 1 wt%, and more than 0.1 wt%, preferably more than 0.3 wt% of the total dry weight of the aqueous curable binder composition.

[0037] The dry weight of the aqueous, curable binder composition when applied to the non or loosely assembled mineral fibres as an aqueous solution or dispersion, may makes up: > 5 wt%, > 10 wt%, > 15 wt%, > 20 wt% or > 25 wt and/or < 95 wt%, < 90 wt%, < 85 wt% or < 80 wt% of the total weight of the aqueous, curable binder composition. The aqueous, curable binder composition may be applied by being sprayed. The aqueous, curable binder composition may be applied to the non or loosely assembled mineral fibres by passing the non or loosely assembled mineral fibres through a spray of the aqueous, curable binder composition or by spraying the aqueous, curable binder composition over the non or loosely assembled mineral fibres. [0038] In one aspect, the aqueous, curable binder composition may be used to make mineral wool insulation products. The method of producing a mineral wool insulation product may comprise the sequential steps of:

- forming a mineral melt from a molten mineral mixture

- forming mineral fibres from the mineral melt

- spraying the aqueous, curable binder composition on to the mineral fibres, notably spraying the aqueous, curable binder composition on to airborne mineral fibres subsequent to formation of the fibres and prior to collection of the fibres to form a blanket of mineral fibres;

- collecting the mineral fibres to which the aqueous, curable binder composition has been applied to form a blanket of mineral fibres; and

- curing the aqueous, curable binder composition by passing the blanket of mineral fibres through a curing oven.

[0039] Prior to curing, the mineral fibres to which the aqueous, curable binder composition has been applied may be collected to form a primary blanket of mineral fibres which is subsequently folded over itself, for example using a pendulum mechanism, to produce a secondary blanket comprising superimposed layers of the primary blanket.

[0040] The dry weight of the aqueous, curable binder composition, notably when applied to the mineral fibres, may make up from 5 wt% to 20 wt%, preferably from 7.5 wt% to 18 wt%, more preferably from 10 wt% to 15 wt%, even more preferably from 12 wt% to 15 wt% of the total weight of the aqueous, curable binder composition.

[0041 ] The curing oven may have a plurality of heating zones having temperatures within the range 200 °C to 350 °C (typically 230°C to 300 °C). A thin, low density product (12 kg/m ³ or less) may be cured by passing through the curing oven in as little as 20 seconds; a thick, high density product (80 kg/m ³ or more) may require a passage of 15 minutes or more in the curing oven. The blanket of mineral fibres may reach a temperature in the range 180 °C - 220 °C during the curing process. The duration of passage of the blanket through the curing oven may be > 0.5 minutes, > 1 minute, > 2 minutes, > 5 minutes or > 10 minutes and/or < 50 minutes, < 40 minutes or < 30 minutes.

[0042] The quantity of cured binder in the cured blanket of mineral fibres may be > 1 %, > 2%, > 2.5%, > 3%, > 3.5% or > 4% and/or < 10% or < 8%. This may be measured by loss on ignition (LOI).

[0043] The mineral fibre product may have a density which is greater than 5, 8 or 10 kg/m ³ and less than 200, 180 or 150 km/m ³ . The mineral fibre product may be a glass wool insulation product having a density greater than 5, 6, 8 or 10 kg/m ³ and less than 125, 80, 60 or 50 kg/m ³ ; it may be a stone wool insulation product having a density greater than 15, 20 or 25 kg/m ³ and less than 220, 200 or 180 kg/m ³ . Such mineral fibre products may: have a thermal conductivity A of less than 0.05 W/mK and greater than 0.02 W/mK measured at 10°C notably in accordance with EN12667; comprise less than 99% by weight and more than 80% by weight mineral fibres; have a thickness of greater than 10 mm, 15mm or 20 mm and less than 400mm, 350 mm or 300 mm. Preferably, such mineral fibre products have, in combination, the aforementioned thermal conductivity A, % weight mineral fibres and thickness.

[0044] The mineral fibre insulation product, notably when it is a low or medium density mineral fibre insulation product, may have

- a nominal thickness in the range 60-260mm; and/or

- a thermal resistance R of R> 3 m ² K/W, preferably R> 4 m ² K/W at a thickness or 200mm; and/or a density in the range 5-40 kg/m ³ , particularly 5-18 kg/m ³ or 7-12 kg/m ³ .

[0045] The mineral fibre insulation product, notably when it is a high density mineral fibre insulation product, may have

- a nominal thickness in the range 20 to 200 mm; and/or

- a thermal resistance R of R>1 .7 m ² K/W, preferably R>2 m ² K/W at a thickness or 100mm; and/or

- a density in the range 100 to 200 kg/m ³ , particularly 130 to 190 kg/m ³ .

[0046] According to one aspect, the aqueous, curable binder composition may be used to make a non-woven mineral fibre veil. The non-woven mineral fibre veil may be manufactured by a wet laid process or a dry laid process. The method of producing the non-woven mineral fibre veil may comprise the sequential steps of:

- forming a mineral fibre web, notably the mineral fibre web may be formed by i) pouring a dispersion of fibres in water, notably chopped mineral fibres, on to a perforated conveyor belt (often referred to as a wire) through which the water is drained to form a non-woven web of fibres or ii) projecting fibres in an airstream towards of perforated conveyor to form a web of non-woven fibres

- applying the aqueous, curable binder composition on to the mineral fibres, notably by coating the aqueous, curable binder composition on to the mineral fibre web; and

- curing the aqueous, curable binder composition by passing the resinated mineral fibre web through a curing oven.

[0047] When the product is a non-woven mineral fibre veil, the quantity of cured binder in the final product may be > 1 %, > 2.5%, > 5%, > 7.5% > 10 %, or > 12.5 % and/or < 25%, < 22.5%, < 20% or < 17.5%. This may be measured by loss on ignition (LOI).

[0048] The thickness of the non-woven mineral fibre veil may be > 0.1 mm or > 0.3 mm and/or < 0.8 mm or < 0.6 mm. When the non-woven mineral fibre veil is a glass veil, the thickness may be > 0.3 mm and < 0.6 mm. The non-woven mineral fibre veil may have a surface weight > 20 g/m ² or > 30 g/m ² or > 40 g/m ² or > 50 g/m ² and/or < 60 g/m ² or < 80 g/m ² or < 100 g/m ² or < 150g/m ² or < 350 g/m ² .

[0049] Methods of manufacturing mineral fibre products according to the present invention allow for cure speeds which are at least equivalent to and indeed faster than those obtained with comparable binder systems; similarly, the dry tensile strength of the cured mineral fibre products is at least equivalent to and indeed in some cases improved when compared to that obtained with comparable binder systems. Surprisingly, the wet strength of mineral fibre products manufactured according to the present invention is significantly improved with respect to that obtained with comparable binder systems. The wet strength provides an indication of the performance after ageing and/or after weathering. The experiments show that the strength after weathering and after tropical ageing as defined below are significantly improved with respect to that obtained with comparable binder systems, thus confirming the improved performance after ageing in humid environment. Without wishing to be being bound by theory, it is believed that the improved properties of the aqueous, curable binder compositions of the present invention are due to the use of the oxirane-containing reactant(s) which cross link into the polymer chain based on the sugar reactant. It is also believed that presence of hydrophobic groups, notably aromatic rings, when present in the oxirane-containing reactant(s) provide enhanced resistance to humid environment even when (c) is in quantity as low as 5 wt% of the total dry weight of (a), (b) and (c) by providing hydrophobic groups within the backbone of the crosslinked polymer resin.

[0050] Embodiment of the invention will now be described, by way of example only.

[0051] Example 1 : Binder weight loss determination, mean dry veil tensile strengths and mean wet tensile strengths of aqueous, curable binder composition

Examples of binder compositions (Table 1) tested on non-woven mineral fibre veils are shown in Table 3 with their respective mean dry veil tensile strengths and mean wet tensile strengths. Binder weight loss determination was also measured for the different binder compositions (Table 2).

Table 1

Key: DMH= dextrose monohydrate (% by dry weight does not take into account the weight of the water of crystallization) ; DAP= diammonium hydrogen phosphate; AR555= Ancarez® AR555 from Evonik comprising a mixture of high molecular weight polymers of BADGE of molecular weight of 700 Da and 1100 Da; Sil 919= Silanil® 919 from BRB International BV, 3-aminopropyltriethoxysilane

The % by dry weight of DMH, DAP and AR555 are given by total dry weight of DMH + DAP +AR555 The % by dry weight of Sil 919 is added on top of the DMH + DAP + AR555 (thus the total of DMH + DAP + AR555 + Sil 919 represents in the present table 100.5 % by dry weight)

The aqueous curable binder compositions of the above Table 1 were prepared by dissolving DMH and DAP in a 1 litre reactor vessel in water at ambient condition (around 20°C) under constant stirring. After 20 minutes, AR555 was added to the resulting solution and stirred under ambient conditions (around 20°C) at a speed of 1000 rpm for 20 minutes using an overhead mechanical stirrer to produce a homogeneous solution. Then, Silanil® 919 was added into the homogeneous solution and stirred to obtain the aqueous, curable binder composition. The aqueous binder compositions were prepared at 22.5 % total solids weight for binder weight loss determination. The binder compositions were prepared at 2% total solids weight for veils for tensile strength evaluation.

Binder weight loss determination:

The aqueous, curable binder compositions were prepared as described above and poured into a petri dish (about 9 g of aqueous binder composition per petri dish, equivalent to 2 g by dry weight of the binder composition). Weight was determined. The Petri dish was then kept for 2 hours in an oven at 140 °C and weighted again. Weight loss was determined; results are shown in the Table 2 below.

Table 2: Evaluation of binder weight loss, at 140 °C for 2 hours. The binder solution contained 22.5% total solids weight.

Veil Binder Impreqnation/Curinq:

A4-sized glass veils comprising phenol formaldehyde (PF) binder were placed into a Carbolite GPC 12/200B general purpose industrial chamber furnace for about 30 minutes at 600 °C to thermally remove the residual PF binder. The resulting PF binder-free glass veils were removed from the oven, allowed to cool to ambient/room temperature over a time period of about 30 minutes, and then fully immersed into a dipping tray (30 cm x 40 cm x 4 cm) comprising about 400 grams of the aqueous, curable binder compositions of Table 1. The binder-impregnated glass veils were then fully cured (using curing oven: Mathis Labdryer, Werner Mathis AG Switzerland). The glass veils were prepared to have 12 wt% of the binder composition being tested (%wt cured binder in the glass veil verified by LOI (loss on ignition).

Dry and Wet Tensile Strength Measurements:

The dry tensile strength of the cured, binder-impregnated glass veils was determined using a Testometric M350-10CT mechanical testing instrument loaded with winTest analysis software, version 4.0.10 (Testometric Company Ltd., Rochdale, UK). For each test, a cured, binder impregnated A4 glass veil was cut into eight (8) equal strips having 1) a length of about 100 mm; 2) a width of about 52.5 mm; and 3) a thickness/depth of about 150 pm, and mounted using top- and bottom-mounted tensile grips.

Each glass veil strip was tested separately using a 50 kg load cell at an automated test speed of 10 mm/min controlled by winTest analysis software. During the tests, the glass veils strips were placed vertically in the grippers of the mechanical testing instrument and the force and extension were fared to zero during the mounting of the sample to the instrument prior to testing. The winTest analysis software indicated maximum load at peak, stress at peak and modulus (stiffness), and the data presented herein is representative of the mean average of the sixteen sample strips.

The average maximum load at peak was determined and assigned as the tensile strength for each glass veil/binder system. For wet tensile strength analyses, the glass veils were immersed in a Grant Scientific SUB Aqua Plus water bath (Grant Instruments, Cambridgeshire, UK) maintained at a temperature of about 80 °C for about 10 minutes, removed from the water bath and excess water was removed using tissue paper prior to introducing the semi-wet veils, which lacked adsorbed moisture due to dabbing with tissue paper as previously described, to the mechanical testing instrument. Table 3

The results show that the example binders provided improved peak dry and peak wet tensile strength, even using a small quantity of the oxirane-containing reactant (5 wt%).

[0052] Example 2: Weathered Stability Analysis

Weathered stability analysis was tested on binder compositions 1 and 2 defined in Table 1 with the protocol defined below. The results are provided in Table 4.

Weathered Stability Analysis:

Cured binder impregnated veils were placed in an autoclave (J8341 , Vessel: PVO2626 with associated safety valve, door interlock and integrated pipework) system. Samples were treated at 90% humidity and at a temperature ranging from 40°C to 121 °C (full cycle, which means there are three stages: (1) air removal stage at 40 °C when cycle is in progress, (2) after removing air the temperature rises to 121 °C at which sterilization started and continues until a certain period (over an hour) and (3) the last stage is the cooling period to zero vessel pressure at safe temperature), at a pressure of up to 2.62 bar. The samples were dried completely at ambient condition for about 24 hours to ensure no moisture remains onto the veils. The autoclave treated samples were tested for tensile strength by means of testometric machine (M350-10CT) as described above. Table 4

Binder composition 2 showed increase tensile strength on dry, wet and weathered conditions compared to comparative binder composition 1 .

[0053] Example 3: Tropical ageing of veils Tropical ageing was tested on binder compositions 1 and 2 defined in Table 1 with the protocol defined below. The results are provided in Table 5.

Tropical Ageing of veils:

A cooling incubator with controlled humidity and temperature (Climacell ECO line, Purchased from MM Group, Germany) was used to tropical ageing the cured binder veils samples for subseguent strength testing. Cured binder impregnated veils were conditioned at 90% ± 1 % humidity and at 60 °C ± 0.1 °C temperature for 7 days, 28 days and 56 days, at a pressure of 1 .014 bar (Climacell ECO line incubator from MM Group, Germany). The tropically aged samples were tested for tensile strength using testometric machine (M350-10CT) as described before (the veils were tested after being removed from the incubator without being dried and thus contained moisture), and the results were compared with those of non-tropically treated veil samples (e.g. dry tensile strength).

Table 5

Binder composition 2 showed a significant improvement of 36 % in tensile strength after 56 days under tropical ageing conditions compared to binder composition 1 , confirming good resistance to ageing in humid environment. [0054] Example 4: Mean dry veil tensile strengths, mean wet tensile strengths and mean weathered tensile strengths of aqueous, curable binder composition

Examples of binder compositions (Table 6) tested on non-woven mineral fibre veils are shown in Table 7 with their respective mean dry veil tensile strengths, mean wet tensile strengths and mean weathered tensile strengths.

Table 6

Key: DMH= dextrose monohydrate (% by dry weight does not take into account the weight of the water of crystallization) ; DAP= diammonium hydrogen phosphate; DER913= D.E.R.™ 913 from Olin; DER915= D.E.R. ® 915 from Olin; DER916= D.E.R.™ 916 from Olin; Sil 919= Silanil® 919 from BRB International BV, 3-aminopropyltriethoxysilane.

The % by dry weight of DMH, DAP, and oxirane-containing reactant (DER913 or DER915 or DER916) are given by total dry weight of DMH + DAP + oxirane-containing-reactant.

The % by dry weight of Sil 919 is added on top of the DMH + DAP + oxirane-containing reactant (DER913 or DER915 or DER916) (thus the total of DMH + DAP + oxirane-containing reactant + Sil 919 represents in the present table 100.5 % by dry weight)

The aqueous curable binder compositions were prepared in the same way as disclosed in example 1 . The protocol for Dry, Wet and Weathered Tensile Strength Measurements are the same as disclosed in Example 1 and Example 2.

Table 7:

The results show that the tested aqueous binder compositions provided good peak dry, peak wet and peak weathered tensile strength.

[0055] Example 5: Mean dry veil tensile strengths, mean wet tensile strengths and mean weathered tensile strengths of aqueous, curable binder composition Examples of binder compositions (Table 8) tested on non-woven mineral fibre veils are shown in Table 9 with their respective mean dry veil tensile strengths, mean wet tensile strengths and mean weathered tensile strengths.

Table 8

Key: DMH, DAP, AR555, DER915, DER916 and Sil919 are the same as previously defined; Oil = GARO ® 217/S from GOVI; Silo = Siloen ® HJS from BRB

Oil is dedusting oil additive and Silo is a silicone additive.

The % by dry weight of DMH, DAP, oxirane-containing reactant (AR555 or DER915 or DER916), Sil919, Oil and Silo are given by total dry weight of DMH + DAP + oxirane-containing reactant + Sil919 + Oil + Silo

The aqueous curable binder compositions were prepared in the same way as disclosed in example 1 , other than that the Oil and Silo which were added following the addition of Silanil® 919 into the homogeneous solution and stirred to obtain the aqueous, curable binder composition. The binder compositions were prepared at 2% total solids weight for veils for tensile strength evaluation.

The protocol for Dry, Wet and Weathered Tensile Strength Measurements are the same as disclosed in Example 1 and Example 2.

Table 9: The results show that the tested aqueous binder compositions provided good peak dry, peak wet and peak weathered tensile strength.