Aqueous composition comprising polyurethanes carrying (METH) acrylate group, producing crosslinked layers with high

Abstract

The invention relates to a composition comprising (i) at least one polyurethane (PU) carrying (meth) acrylate groups and COOH groups, which COOH groups are at least partially in the form of their salt groups, which polyurethane is obtainable by the reaction of: at least one polyisocyanate (A); at least one polyol (B1) carrying at least one COOH group; at least one polyol (B2) carrying at least one (meth) acrylate group but not a COOH group and comprising at least one aromatic ring; at least one polyol (B3) which is an ester of glycerol with at least one carboxylic acid bearing at least 6 carbon atoms, or which is derived from an ester of glycerol with at least one carboxylic acid bearing at least 6 carbon atoms wherein the polyol has a hydroxyl number in the range of 10 to 250 and does not carry COOH groups and (meth) acrylate groups and does not contain at least one aromatic ring; optionally at least one monohydric alcohol (B4) carrying at least one (meth) acrylate group and not carrying a COOH group; and optionally at least one compound, oligomer or polymer (B5) carrying at least one OH group and being different from B1, B2 and B3 and B4; and optionally at least one compound (C) carrying at least one NH2 group and not carrying OH groups wherein the equivalence ratio of OH groups of B2 / OH groups of B1, B2, B3, B4 and B5 is at least 45% and wherein the weight ratio of B3 / (A, B1, B2, B3, B4, B5 and C) is at least 1%, (ii) optionally at least one compound (1) carrying at least one ethylenically unsaturated group and not carrying COOH groups, and (iii) water, and to an aqueous coating composition comprising the composition, a crosslinked layer formed from the aqueous coating composition, and a substrate coated with the layer.

Description

[0001] The present invention relates to an aqueous composition comprising a polyurethane carrying (meth)acrylate groups, an aqueous coating composition comprising these compositions, a crosslinked layer formed from these coating compositions, and a substrate coated with these layers.

[0002] The aqueous composition comprising a polyurethane carrying (meth)acrylate groups is used as a binder in many applications such as coating compositions (such as topcoat compositions, colorant compositions), ink compositions, and adhesive compositions.

[0003] It is desirable that the crosslinked layer formed from these compositions on a substrate exhibits high hardness and good adhesion to the substrate.

[0004] WO 2011107398 (Bayer) describes an aqueous radiation-curable dispersion based on polyurethane acrylate, wherein the polyurethane acrylate contains the following components as forming compounds: (A) one or more aromatic polyepoxy(meth)acrylates having an OH value of 20 to 300 mg KOH / g of substance; C) one or more low polyesters or polyesters containing unsaturated fatty acids having an OH value of 15 to 300 mg KOH / g of substance and an iodine value greater than 50 g I2 / 100 g of substance; E) one or more compounds having at least one group reactive toward isocyanate and additionally at least one hydrophilic group; and F) one or more organic polyisocyanates.

[0005] The object of the present invention is to provide aqueous ethylenically unsaturated polyurethane compositions and coating compositions comprising these compositions, which coating compositions form crosslinked layers exhibiting good Martens hardness and indentation hardness and good adhesion to the substrate.

[0006] This object is solved by the composition according to claim 1, the coating composition according to claim 14, the layer according to claim 15, and the coated substrate according to claim 16.

[0007] The composition of the present invention is a composition comprising the following:

[0008] (i) at least one polyurethane PU carrying (meth)acrylate groups and COOH groups, at least a part of these COOH groups being in the form of their salt groups, and the polyurethane can be obtained by the reaction of:

[0009] at least one polyisocyanate (A),

[0010] at least one polyol (B1) carrying at least one COOH group,

[0011] At least one polyol (B2) which bears at least one (meth)acrylate group but no COOH group and contains at least one aromatic ring,

[0012] At least one polyol (B3) which is an ester of glycerol and at least one carboxylic acid bearing at least 6 carbon atoms, or is derived from an ester of glycerol and at least one carboxylic acid bearing at least 6 carbon atoms, wherein the polyol has a hydroxyl value in the range of 10 to 250 and bears no COOH group and no (meth)acrylate group and contains no at least one aromatic ring,

[0013] Optionally at least one monohydric alcohol (B4) which bears at least one (meth)acrylate group and no COOH group, and

[0014] Optionally at least one compound, oligomer or polymer (B5) which bears at least one OH group and is different from B1, B2, B3 and B4,

[0015] Optionally at least one compound (C) which bears at least one NH2 group and no OH group,

[0016] wherein the equivalent ratio of the OH groups of B2 to the OH groups of B1, B2, B3, B4 and B5 is at least 45%, and wherein the weight ratio of B3 / (A, B1, B2, B3, B4, B5 and C) is at least 1%,

[0017] (ii) Optionally at least one compound (1) which bears at least one ethylenically unsaturated group and no COOH group

[0018] and

[0019] (iii) Water.

[0020] The equivalent ratio of the OH groups of B2 to the OH groups of B1, B2, B3, B4 and B5 is preferably at least 50%, more preferably at least 55%.

[0021] The weight ratio of B3 / (A, B1, B2, B3, B4, B5 and C) is preferably in the range of 2% to 30%, more preferably in the range of 3% to 25%, and most preferably in the range of 5% to 18%.

[0022] The term “(meth)acrylate” includes acrylate and methacrylate. Acrylate has the formula -O-C(=O)-CH=CH2. Methacrylate has the formula -O-C(=O)-C(CH3)=CH2.

[0023] The polyol has an OH functionality of at least 1.5.

[0024] The OH functionality of a polyol is (the hydroxyl value of the polyol [g KOH / g] × the molecular weight of the polyol) / the molecular weight of KOH. If the polyol is an oligomer or polymer, the number-average molecular weight of the polyol is used, which can be determined by gel permeation chromatography calibrated with polystyrene standards. The molecular weight of KOH is 56 g / mol. The hydroxyl value of the polyol can be determined according to DIN53240, 2016.

[0025] The polyol can be an aliphatic, alicyclic or aromatic polyol.

[0026] An aromatic polyol is a polyol in which at least one OH functional group is directly attached to an aromatic ring. An alicyclic polyol contains at least one alicyclic ring, and each OH functional group is not directly attached to an aromatic ring. An aliphatic polyol does not contain an alicyclic ring, and each OH functional group is not directly attached to an aromatic ring. Preferred aliphatic and alicyclic polyols do not contain an aromatic ring.

[0027] A monohydric alcohol has an OH functionality of less than 1.5.

[0028] The OH functionality of a monohydric alcohol is (the hydroxyl value of the monohydric alcohol [g KOH / g] × the molecular weight of the monohydric alcohol) / the molecular weight of KOH. If the monohydric alcohol is an oligomer or polymer, the number-average molecular weight of the monohydric alcohol is used, which can be determined by gel permeation chromatography calibrated with polystyrene standards. The molecular weight of KOH is 56 g / mol. The hydroxyl value of the monohydric alcohol can be determined according to DIN53240, 2016.

[0029] The monohydric alcohol can be an aliphatic, alicyclic or aromatic monohydric alcohol.

[0030] An aromatic monohydric alcohol is a monohydric alcohol in which the OH functional group is directly attached to an aromatic ring. An alicyclic monohydric alcohol contains at least one alicyclic ring, and each OH functional group is not directly attached to an aromatic ring. An aliphatic monohydric alcohol does not contain an alicyclic ring, and the OH functional group is not directly attached to an aromatic ring. Preferred aliphatic and alicyclic monohydric alcohols do not contain an aromatic ring.

[0031] The ethylenically unsaturated group can be any ethylenically unsaturated group that can polymerize by a free radical mechanism under heating, radiation treatment (usually UV radiation treatment), in the presence of a suitable initiator, or under electron beam treatment. Examples of ethylenically unsaturated groups are acryloyl, methacryloyl, vinyl and allyl. Preferred ethylenically unsaturated groups are selected from the group consisting of acryloyl and methacryloyl. More preferred ethylenically unsaturated group is acryloyl.

[0032] The polyisocyanate comprises a polyisocyanate carrying blocked NCO groups and a polyisocyanate carrying free NCO groups. The polyisocyanate carrying blocked NCO groups can be deblocked under specific conditions (e.g., at high temperature, such as at a temperature above 110 °C) to obtain the corresponding polyisocyanate carrying free NCO groups. The polyisocyanate carrying blocked NCO groups is characterized via its corresponding polyisocyanate carrying free NCO groups as follows. Preferably, the polyisocyanate only comprises the polyisocyanate carrying free NCO groups.

[0033] The polyisocyanate has an NCO functionality of at least 1.5.

[0034] The NCO functionality of the polyisocyanate is NCO content × (molecular weight of the polyisocyanate / molecular weight of NCO). If the polyisocyanate is a polymeric polyisocyanate, the weight-average molecular weight of the polyisocyanate is used. The weight-average molecular weight of the polymeric polyisocyanate can be determined by gel permeation chromatography calibrated with polystyrene standards. The NCO content of the polyisocyanate is weight of NCO / weight of the polyisocyanate. The molecular weight of NCO is 42 g / mol.

[0035] The NCO content of the polyisocyanate can be determined as follows:

[0036] Add 10 mL of a 1N solution of di-n-butylamine in xylene to 1 g of the polyisocyanate dissolved in 100 mL of N-methylpyrrolidone. Stir the resulting mixture at room temperature for five minutes. Then, back-titrate the resulting reaction mixture with 1N hydrochloric acid to measure the volume of hydrochloric acid required to neutralize the unreacted di-n-butylamine. This reveals how many moles of di-n-butylamine reacted with the NCO groups. The NCO content is (moles of reacted di-n-butylamine × molecular weight of NCO) / weight of the polyisocyanate. The weight of the polyisocyanate is 1 g.

[0037] The polyisocyanate can be an aliphatic, cycloaliphatic or aromatic polyisocyanate.

[0038] An aromatic polyisocyanate is a polyisocyanate in which at least one NCO functional group is directly attached to an aromatic ring. A cycloaliphatic polyisocyanate contains at least one cycloaliphatic ring, and each NCO functional group is not directly attached to an aromatic ring. An aliphatic polyisocyanate does not contain a cycloaliphatic ring, and each NCO functional group is not directly attached to an aromatic ring. Preferred aliphatic and cycloaliphatic polyisocyanates do not contain an aromatic ring.

[0039] The polyol (B1) carrying at least one COOH group can be any aliphatic, cycloaliphatic or aromatic polyol (B1) carrying at least one COOH group.

[0040] The OH functionality of the polyol (B1) carrying at least one COOH group is generally in the range of 1.7 to 6.0, more preferably in the range of 1.8 to 5.4, even more preferably in the range of 1.8 to 3.4, most preferably in the range of 1.8 to 2.4, and particularly in the range of 1.9 to 2.2.

[0041] The polyol (B1) carrying at least one COOH group preferably has a number-average molecular weight of less than 750 g / mol, more preferably less than 500 g / mol, and most preferably less than 250 g / mol.

[0042] Examples of the polyol (B1) carrying one COOH group are 2,2-bis(hydroxymethyl) C 2-10 -alkanoic acids such as 2,2-bis(hydroxymethyl)propionic acid (dihydroxymethylpropionic acid), 2,2-bis(hydroxymethyl)butyric acid, and 2,2-bis(hydroxymethyl)valeric acid.

[0043] The polyol (B1) carrying at least one COOH group is preferably a polyol carrying one COOH group, more preferably an aliphatic or alicyclic polyol (B1) carrying one COOH group, and even more preferably an aliphatic polyol (B1) carrying one COOH group. Most preferably, the polyol (B1) is selected from the group consisting of 2,2-bis(hydroxymethyl)propionic acid and 2,2-bis(hydroxymethyl)butyric acid, and particularly 2,2-bis(hydroxymethyl)propionic acid.

[0044] The polyol (B2) carrying at least one (meth)acrylate group but not carrying a COOH group and containing at least one aromatic ring can be any polyol carrying at least one (meth)acrylate group but not carrying a COOH group and containing at least one aromatic ring.

[0045] The aromatic ring can be any aromatic ring. Examples of the aromatic ring are a benzene ring and a naphthalene ring.

[0046] The OH functionality of the polyol (B2) is generally in the range of 1.7 to 6.0, more preferably in the range of 1.8 to 5.4, even more preferably in the range of 1.8 to 3.4, most preferably in the range of 1.8 to 2.4, and particularly in the range of 1.9 to 2.2.

[0047] The polyol (B2) preferably has a number-average molecular weight in the range of 250 to 750 g / mol.

[0048] The polyol (B2) preferably has the following formula

[0049]

[0050] wherein L1 Selected from the group consisting of:

[0051]

[0052] The polyol (B2) more preferably has the following formula

[0053]

[0054] wherein L 1 Selected from the group consisting of:

[0055]

[0056] The polyol (B2) most preferably has the following formula

[0057]

[0058] wherein L 1 is

[0059]

[0060] The polyol (B3) can be any polyol that is an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, wherein the polyol has a hydroxyl value in the range of 10 to 250, does not carry COOH groups and (meth)acrylate groups and does not contain at least one aromatic ring.

[0061] The ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms can be a monoester, diester or triester. The monoester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms also includes a mixture of monoesters of glycerol with different carboxylic acids carrying at least 6 carbon atoms. The carboxylic acids carrying at least 6 carbon atoms in the diester or triester can be the same or different. The diester and triester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms also respectively include mixtures of the diester and triester.

[0062] The carboxylic acid carrying at least 6 carbon atoms can carry additional substituents such as OH groups.

[0063] The carboxylic acid carrying at least 6 carbon atoms can be a saturated carboxylic acid carrying at least 6 carbon atoms or an unsaturated carboxylic acid carrying at least 6 carbon atoms.

[0064] Examples of saturated carboxylic acids carrying at least 6 carbon atoms are caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid (C12), myristic acid (C14), palmitic acid (C16), stearic acid (C18), dihydroxystearic acid, arachidic acid (C20), behenic acid (C22), lignoceric acid (C24) and cerotic acid (C26).

[0065] Examples of unsaturated carboxylic acids having at least 6 carbon atoms are myristoleic acid (C14), palmitoleic acid (C16), petroselinic acid (C16), oleic acid (C18), elaidic acid (C18), vaccenic acid (C18), linoleic acid (C18), linolelaidic acid, α-linolenic acid (C18), ricinoleic acid (c18), arachidonic acid (C20), eicosapentaenoic acid (C20), erucic acid (C22).

[0066] The polyol (B3) is preferably an ester of glycerol and at least one carboxylic acid having at least 10 carbon atoms and at most 21 carbon atoms, wherein the polyol has a hydroxyl value in the range of 50 to 250, and does not carry a COOH group and a (meth)acrylate group and does not contain at least one aromatic ring.

[0067] The polyol (B3) is more preferably a triester of glycerol and at least one carboxylic acid having at least 10 carbon atoms and at most 21 carbon atoms, and wherein at least one of these carboxylic acids also carries at least one OH group, and wherein the polyol has a hydroxyl value in the range of 50 to 250, does not carry a COOH group and a (meth)acrylate group and does not contain at least one aromatic ring.

[0068] Examples of carboxylic acids having at least 10 carbon atoms and at most 21 carbon atoms and also carrying at least one OH group are ricinoleic acid, partially and fully hydrogenated ricinoleic acid, and at least monohydroxylated carboxylic acids which can be obtained from mono- or polyunsaturated carboxylic acids having at least 10 carbon atoms and at most 21 carbon atoms.

[0069] The at least monohydroxylated carboxylic acids can be obtained, for example, from unsaturated carboxylic acids having at least 10 carbon atoms and at most 21 carbon atoms by complete or partial epoxidation of one or more ethylenically unsaturated bonds followed by ring opening of the epoxide ring with formation of an OH group. Epoxidation can be carried out by methods known in the art, such as by treating the unsaturated carboxylic acid with a peroxyacid or a peroxide. Hydroxylation can also be carried out by methods known in the art. For example, if the epoxidation is carried out in an aqueous medium, hydroxylation of the epoxide ring occurs.

[0070] Examples of the polyol (B3) are castor oil and partially or fully hydrogenated castor oil.

[0071] Further examples of the polyol (B3) are vegetable or animal oils which are at least monohydroxylated and optionally partially or fully hydrogenated, which are triesters of glycerol and at least one carboxylic acid having at least 10 and at most 21 carbon atoms, and in which at least one of these carboxylic acids also bears at least one OH group, and in which the at least monohydroxylated and optionally partially or fully hydrogenated vegetable or animal oil has a hydroxyl value in the range from 10 to 250, bears no COOH groups and (meth)acrylate groups and contains no at least one aromatic ring.

[0072] Examples of vegetable and animal oils suitable for the preparation of at least monohydroxylated and optionally partially or fully hydrogenated vegetable and animal oils are rapeseed oil, cod liver oil, corn oil, cottonseed oil, safflower oil, linseed oil, olive oil, palm oil, peanut oil, sesame oil, soybean oil, sunflower oil and walnut oil. The preparation of at least monohydroxylated and optionally partially or fully hydrogenated vegetable and animal oils is known in the art and is described, for example, in US20100267925A1.

[0073] The polyol (B3) is even more preferably a triester of glycerol and at least one carboxylic acid having at least 10 and at most 21 carbon atoms, in which at least one of these carboxylic acids also bears at least one OH group and in which at least 50% by weight of these carboxylic acids are carboxylic acids having at least 16 and at most 21 carbon atoms, and in which the polyol has a hydroxyl value in the range from 50 to 250, bears no COOH groups and (meth)acrylate groups and contains no at least one aromatic ring.

[0074] The polyol (B3) is most preferably a triester of glycerol and at least one carboxylic acid having at least 10 and at most 21 carbon atoms, in which at least one of these carboxylic acids also bears at least one OH group and in which at least 75% by weight of these carboxylic acids are carboxylic acids having at least 16 and at most 21 carbon atoms, and in which the polyol has a hydroxyl value in the range from 50 to 250, bears no COOH groups and (meth)acrylate groups and contains no at least one aromatic ring.

[0075] The polyol (B3) is even most preferably a triester of glycerol and at least one carboxylic acid having at least 10 and at most 21 carbon atoms, in which at least one of these carboxylic acids also bears at least one OH group and in which at least 80% by weight of these carboxylic acids are ricinoleic acid or fully or partially hydrogenated ricinoleic acid, and in which the polyol has a hydroxyl value in the range from 50 to 250, bears no COOH groups and (meth)acrylate groups and contains no at least one aromatic ring.

[0076] The polyol (B3) is in particular castor oil or partially or fully hydrogenated castor oil.

[0077] The triesters of glycerol and ricinoleic acid are the main components of castor oil. The triesters of glycerol and hydrogenated ricinoleic acid are the main components of hydrogenated castor oil.

[0078] The monohydric alcohol (B4) carrying at least one (meth)acryloyl group can be any aliphatic, alicyclic or aromatic monohydric alcohol carrying at least one (meth)acryloyl group and not carrying a COOH group.

[0079] The monohydric alcohol (B4) preferably has an OH functionality in the range of 0.8 to 1.4, preferably in the range of 0.9 to 1.2.

[0080] Examples of the monohydric alcohol (B4) carrying at least one (meth)acryloyl group are the monoester of a diol and acrylic acid or methacrylic acid, the diester of a triol and acrylic acid or methacrylic acid, and the triester of a tetraol and acrylic acid or methacrylic acid and the pentaester of a hexol and acrylic acid or methacrylic acid.

[0081] Examples of the monoester of a diol and acrylic acid or methacrylic acid are C 1-10 -aliphatic diols, preferably C 1-6 -aliphatic diols and the monoester of acrylic acid or methacrylic acid.

[0082] C 1-6 -Examples of the monoester of an aliphatic diol and acrylic acid or methacrylic acid are 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate and 4-hydroxybutyl acrylate.

[0083] Further examples of the monohydric alcohol (B4) carrying at least one (meth)acryloyl group are the diester of ethoxylated or propoxylated 1,1,1-trimethylolpropane and acrylic acid or methacrylic acid, the triester of pentaerythritol and acrylic acid or methacrylic acid, the triester of ethoxylated or propoxylated bis(1,1,1-trimethylol)propane and acrylic acid or methacrylic acid and the pentaester of dipentaerythritol.

[0084] The monohydric alcohol (B4) is preferably an aliphatic or alicyclic monohydric alcohol carrying one (meth)acryloyl group. More preferably, the monohydric alcohol (B4) is an aliphatic or alicyclic monohydric alcohol carrying one acryloyl group. Even more preferably, the monohydric alcohol (B4) is the monoester of a C 1-6 -aliphatic diol and acrylic acid, and most preferably, the monohydric alcohol (B4) is 2-hydroxyethyl acrylate.

[0085] A compound, oligomer or polymer (B5) that carries at least one OH group and is different from B1, B2, B3 and B4 can be any compound, oligomer or polymer that is different from B1, B2, B3 and B4 and carries at least one OH group. The compound, oligomer or polymer (B5) can also carry at least one ethylenically unsaturated group.

[0086] The compound, oligomer or polymer (B5) can be an aliphatic, alicyclic or aromatic polyol that is different from B1, B2 and B3.

[0087] Examples of aliphatic polyols that are different from B1, B2 and B3 are ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, butane-2,3-diol, pentane-1,2-diol, pentane-1,3-diol, pentane-1,4-diol, pentane-1,5-diol, pentane-2,3-diol, pentane-2,4-diol, hexane-1,2-diol, hexane-1,3-diol, hexane-1,4-diol, hexane-1,5-diol, hexane-1,6-diol, hexane-2,5-diol, heptane-1,2-diol, heptane-1,7-diol, octane-1,8-diol, octane-1,2-diol, nonane-1,9-diol, decane-1,2-diol, decane-1,10-diol, dodecane-1,2-diol, dodecane-1,12-diol, hex-1,5-diene-3,4-diol, neopentyl glycol, 2-methyl-pentane-2,4-diol, 2,4-dimethyl-pentane-2,4-diol, 2-ethyl-hexane-1,3-diol, 2,5-dimethyl-hexane-2,5-diol, 2,2,4-trimethyl-pentane-1,3-diol, pinacol and neopentyl glycol hydroxypivalate.

[0088] Further examples of aliphatic polyols that are different from B1, B2 and B3 are di(ethylene glycol), tri(ethylene glycol), di(propylene glycol) and tri(propylene glycol).

[0089] Further examples of aliphatic polyols that are different from B1, B2 and B3 are glycerol, trimethylolethane, 1,1,1-trimethylolpropane, 1,2,4-butanetriol and 1,3,5-tris(2-hydroxyethyl)isocyanurate, and condensates thereof with ethylene oxide, propylene oxide and / or butylene oxide.

[0090] Further examples of aliphatic polyols that are different from B1, B2 and B3 are pentaerythritol, diglycerol, triglycerol, condensates of at least four glycerols, di(trimethylolpropane), di(pentaerythritol), and condensates thereof with ethylene oxide, propylene oxide and / or butylene oxide.

[0091] Examples of alicyclic polyols different from B1, B2 and B3 are 1,1-bis(hydroxymethyl)-cyclohexane, 1,2-bis(hydroxymethyl)-cyclohexane, 1,3-bis(hydroxymethyl)-cyclohexane, 1,4-bis(hydroxymethyl)-cyclohexane, 1,1-bis(hydroxyethyl)-cyclohexane, 1,2-bis(hydroxyethyl)-cyclohexane, 1,3-bis(hydroxyethyl)-cyclohexane, 1,4-bis(hydroxyethyl)-cyclohexane, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, cyclopentane-1,2-diol, cyclopentane-1,3-diol, 1,2-bis(hydroxymethyl)cyclopentane, 1,3-bis(hydroxymethyl)cyclopentane, cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cycloheptane-1,3-diol and cycloheptane-1,4-diol and cycloheptane-1,2-diol.

[0092] Examples of polyols different from B1, B2 and B3 are inositol, sugars such as glucose, fructose and sucrose, sugar alcohols such as sorbitol, mannitol, threitol, erythritol, adonitol (ribitol), arabinitol (lyxitol), xylitol, dulcitol (galactitol), maltitol and isomaltitol, and tris(hydroxymethyl)amine, tris(hydroxyethyl)amine and tris(hydroxypropyl)amine.

[0093] Examples of polyols different from B1, B2 and B3 are also polyurethane polyols, polyester polyols, polycarbonate polyols, polyether polyols, polythioether polyols and polyacrylate polyols.

[0094] A polyurethane polyol is a polymeric polyol containing urethane groups as the linking groups between two monomer units, where the equivalent ratio of urethane linking groups / all linking groups is at least 50 / 50, preferably at least 70 / 100, more preferably at least 80 / 100. The polyurethane polyol may contain additional linking groups such as carbonate, ether, thioether or ester groups.

[0095] A polyester polyol is a polymeric polyol containing ester groups as the linking groups between two monomer units, where the equivalent ratio of ester linking groups / all linking groups is at least 50 / 50, preferably at least 70 / 100, more preferably at least 80 / 100. The polyester polyol may contain additional linking groups such as carbonate, ether, thioether or urethane groups.

[0096] The polyester polyol can be prepared by methods known in the art, for example, by reacting at least one polybasic acid having a COOH functionality in the range of 1.8 to 2.4 with a polyol having an OH functionality in the range of 1.8 to 2.4. Examples of polybasic acids having a COOH functionality of 2 are aliphatic polybasic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 2-methylmalonic acid, 2-ethylmalonic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid, 3,3-dimethylglutaric acid, 2-phenylmalonic acid, 2-phenylsuccinic acid, alicyclic polybasic acids such as cyclopentane-1,2-dicarboxylic acid, cyclopentane-1,3-dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, cycloheptane-1,2-dicarboxylic acid, 1,2-bis(carboxymethyl)-cyclohexane, 1,3-bis(carboxymethyl)-cyclohexane and 1,4-bis(carboxymethyl)-cyclohexane, and aromatic polybasic acids such as 2-5-furandicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and bis(4-carboxyphenyl)methane.

[0097] Examples of the polyester polyol also include polycaprolactone diol.

[0098] The polycarbonate polyol is a polymer polyol containing at least two carbonate groups in the main chain of the polymer. The polycarbonate polyol may contain additional linking groups in the main chain in an amount less than the number of carbonate groups, such as ester, ether, thioether or urethane linking groups. Examples of the polycarbonate polyol are polycarbonates that do not carry a COOH group and contain units derived from the group consisting of butane-1,4-diol, pentane-1,5-diol and hexane-1,6-diol. Preferred polycarbonate polyols are those polycarbonate polyols in which the equivalent ratio of carbonate groups / all linking groups is at least 70 / 100, more preferably at least 80 / 100.

[0099] The polyether polyol is a polymer polyol containing at least two ether groups in the main chain of the polymer. The polyether polyol may contain additional linking groups in the main chain in an amount less than the number of ether groups, such as ester, carbonate, thioether or urethane groups.

[0100] Preferred polyether polyols are those polyether polyols in which the equivalent ratio of ether groups / all linking groups is at least 70 / 100, more preferably at least 80 / 100.

[0101] Examples of the polyether polyol are polyethylene glycol, polypropylene glycol, polyethylene glycol - polypropylene glycol, polytetramethylene glycol and polytetrahydrofuran diol. Polyethylene glycol - polypropylene glycol can be a random copolymer or a block copolymer

[0102] A polythiol polyol is a polymeric polyol that does not carry ethylenically unsaturated groups and COOH groups and has at least two thioether groups in the polymer main chain. The polythiol polyol may contain additional linking groups in the main chain in a number less than the number of ether groups, such as ester, carbonate, ether or urethane groups.

[0103] A poly(meth)acrylate polyol is a polymeric polyol containing at least two units derived from (meth)acrylate monomers carrying at least one OH group, such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

[0104] The polyisocyanate (A) can be any aliphatic, cycloaliphatic or aromatic polyisocyanate, which can be a monomeric or polymeric polyisocyanate.

[0105] Examples of monomeric aliphatic polyisocyanates that do not carry ethylenically unsaturated groups are tetramethylene 1,4-diisocyanate, pentamethylene 1,5-diisocyanate, hexamethylene 1,6-diisocyanate, heptamethylene 1,7-diisocyanate, octamethylene 1,8-diisocyanate, decamethylene 1,10-diisocyanate, dodecamethylene 1,12-diisocyanate, tetradecamethylene 1,14-diisocyanate, methyl 2,6-diisocyanatohexanoate, ethyl 2,6-diisocyanatohexanoate, 2,2,4-trimethylhexane 1,6-diisocyanate and 2,4,4-trimethylhexane 1,6-diisocyanate.

[0106] Further examples of monomeric aliphatic polyisocyanates that do not carry ethylenically unsaturated groups are 1,4,8-triisocyanatononane and 2'-isocyanatoethyl 2,6-diisocyanatohexanoate.

[0107] Examples of monomeric cycloaliphatic polyisocyanates that do not carry ethylenically unsaturated groups are 1,4-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,2-diisocyanatocyclohexane, 4,4'-bis(isocyanatocyclohexyl)methane, 2,4'-bis(isocyanatocyclohexyl)methane, 1-isocyanato-3,3,5-trimethyl-5-(isocyanatomethyl)cyclohexane (isophorone diisocyanate), 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 2,4-diisocyanato-1-methylcyclohexane, 2,6-diisocyanato-1-methylcyclohexane and 3(or 4),8(or 9)-bis(isocyanatomethyl)tricyclo[5.2.1.0(2,6)]decane.

[0108] Examples of monomeric aromatic polyisocyanates that do not carry ethylenically unsaturated groups are 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 2,4'-diisocyanatodiphenylmethane, 4,4'-diisocyanatodiphenylmethane, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-chloro-2,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate, diphenylene 4,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, 3-methyldiphenylmethane 4,4'-diisocyanate, tetramethylxylylene diisocyanate, 1,4-diisocyanatobenzene, and diphenyl ether 4,4'-diisocyanate.

[0109] Further examples of monomeric aromatic polyisocyanates that do not carry ethylenically unsaturated groups are 2,4,6-triisocyanatotoluene, triphenylmethane triisocyanate, and 2,4,4'-triisocyanatodiphenyl ether.

[0110] Monomeric polyisocyanates that do not carry ethylenically unsaturated groups can be prepared by methods known in the art, for example, by treating the corresponding amine with phosgene.

[0111] Polymeric polyisocyanates contain at least two units derived from monomeric polyisocyanates. Polymeric polyisocyanates typically also contain at least one structural unit selected from the group consisting of uretdione, isocyanurate, biuret, urea, carbodiimide, uretonimine, urethane, allophanate, oxadiazinetrione, and iminooxadiazinedione.

[0112] The NCO functionality of the polyisocyanate (A) is generally in the range of 1.6 to 10.0, preferably in the range of 1.6 to 8.0, more preferably in the range of 1.7 to 5.4, even more preferably in the range of 1.8 to 3.4, and most preferably in the range of 1.8 to 2.4.

[0113] The polyisocyanate (A) can carry at least one ethylenically unsaturated group or no ethylenically unsaturated group.

[0114] The polyisocyanate (A) carrying at least one ethylenically unsaturated group preferably has an ethylenically unsaturated group density in the range of 0.10 to 10.00 milliequivalents of ethylenically unsaturated groups / g, more preferably 0.50 to 5.00 milliequivalents of ethylenically unsaturated groups / g, and most preferably 1.50 to 2.50 milliequivalents of ethylenically unsaturated groups / g (A1). The ethylenically unsaturated group density of the polyisocyanate (A1) is determined by 1 1H-NMR.

[0115] The polyisocyanate (A) preferably does not carry an ethylenically unsaturated group.

[0116] The compound (C) carrying at least one NH2 group and not carrying an OH group can be any aliphatic, cycloaliphatic or aromatic compound carrying at least one NH2 group and not carrying an OH group.

[0117] The aromatic compound (C) is a compound (C) in which at least one NH2 functional group is directly attached to an aromatic ring. The cycloaliphatic compound (C) contains at least one cycloaliphatic ring, and each NH2 functional group is not directly attached to an aromatic ring. The aliphatic compound (C) does not contain a cycloaliphatic ring, and each NH2 functional group is not directly attached to an aromatic ring. Preferred aliphatic and cycloaliphatic compounds (C) do not contain an aromatic ring.

[0118] The compound (C) carrying at least one NH2 group and not carrying an OH group may also carry other functional groups such as NH or acidic groups such as SO3H, PO3H, or COOH or their salt groups.

[0119] Examples of the compound (C) are ethylenediamine, isophoronediamine, sodium N-aminoethyl-2-aminoethanesulfonate, sodium N-aminoethyl-2-aminoethanecarboxylate, and the sodium salt of lysine.

[0120] The compound (C) carrying at least one NH2 group and not carrying an OH group is preferably an aliphatic or cycloaliphatic compound carrying one NH2 group and not carrying an OH group.

[0121] The components (A), (B1), (B2), (B3), (B4), (B5) and (C) can be derived from fossil or renewable resources such as plants. Whether a component is derived from a renewable resource can be determined by the C-14 / C-12 isotope ratio.

[0122] The C-14 / C-12 isotope ratio of the component (B3) preferably does not deviate from the C-14 / C-12 isotope ratio of the atmosphere by more than 10%, more preferably it does not deviate from the C-14 / C-12 isotope ratio of the atmosphere by more than 5%, and most preferably it does not deviate from the C-14 / C-12 isotope ratio of the atmosphere by more than 1%.

[0123] The polyurethane (PU) carrying (meth)acrylate groups and COOH groups (at least part of these COOH groups being in the form of their salt groups) preferably has a number-average molecular weight Mn in the range from 750 g / mol to 500000 g / mol.

[0124] The polyurethane (PU) carrying (meth)acrylate groups and COOH groups (where at least some of these COOH groups are in the form of their salt groups) preferably has a weight-average molecular weight Mw in the range of 1500 g / mol to 1000000 g / mol.

[0125] The number-average molecular weight Mn and the weight-average molecular weight Mw can be determined by gel permeation chromatography calibrated with polystyrene standards.

[0126] The salt groups of the COOH groups can be any salt groups of the COOH groups formed by the reaction of the COOH groups with a base.

[0127] The base can be an inorganic base or a compound carrying at least one tertiary amino group.

[0128] Examples of inorganic bases are alkali metal and alkaline earth metal hydroxides, alkali metal and alkaline earth metal carbonates, and alkali metal and alkaline earth metal bicarbonates. Preferred inorganic bases are alkali metal hydroxides such as sodium hydroxide or potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, and alkali metal bicarbonates such as sodium bicarbonate and potassium bicarbonate.

[0129] Examples of compounds carrying at least one tertiary amino group are triethanolamine, tripropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, triethylamine, ethyldiisopropylamine, tripropylamine, triisopropylamine, and tri-n-butylamine.

[0130] In a preferred embodiment, the base is a compound carrying at least one tertiary amino group.

[0131] The equivalent ratio of the salt groups of the COOH groups of the polyurethane (1) / (COOH groups and their salt groups) is preferably in the range of 40 / 100 to 100 / 100, and more preferably in the range of 60 / 100 to 100 / 100.

[0132] The density of the COOH groups and their salt groups of the polyurethane (PU) is preferably at least 0.20 meq COOH groups and their salt groups / g polyurethane (PU), and more preferably at least 0.30 meq COOH groups and their salt groups / g polyurethane (PU), and most preferably in the range of 0.35 to 0.50 meq COOH groups and their salt groups / g of the solid of the polyurethane (PU).

[0133] The density of the COOH groups and their salt groups of the polyurethane (PU) is the sum of:

[0134] [Weight ratio (B1) / (A), (B1), (B2), (B3), (B4), (B5) and (C)] multiplied by the COOH group density of (B1), and

[0135] [Weight ratio (B5) / (A), (B1), (B2), (B3), (B4), (B5) and (C)] multiplied by the COOH group density of (B5), and

[0136] [Weight ratio (C) / (A), (B1), (B2), (B3), (B4), (B5) and (C)] multiplied by the COOH group density of (C).

[0137] The (meth)acrylate group density of the polyurethane (PU) is preferably at least 0.50 meq (meth)acrylate groups / g of polyurethane (PU), more preferably in the range of 0.80 to 6.00 meq (meth)acrylate groups / g of polyurethane (PU), even more preferably in the range of 1.00 to 4.00 meq (meth)acrylate groups / g of polyurethane (PU), and most preferably in the range of 1.50 to 3.50 meq (meth)acrylate groups / g of polyurethane (PU).

[0138] The (meth)acrylate group density of the polyurethane (PU) is determined by calculation. The (meth)acrylate group density of the polyurethane (PU) is the sum of the following:

[0139] [Weight ratio (A) / (A), (B1), (B2), (B4), (B5) and (C)] multiplied by the (meth)acrylate group density of (A)],

[0140] [Weight ratio (B1) / (A), (B1), (B2), (B4), (B5) and (C)] multiplied by the (meth)acrylate group density of (B1)],

[0141] [Weight ratio (B2) / (A), (B1), (B2), (B4), (B5) and (C)] multiplied by the (meth)acrylate group density of (B2)],

[0142] [Weight ratio (B4) / (A), (B1), (B2), (B4), (B5) and (C)] multiplied by the (meth)acrylate group density of (B4)

[0143] [Weight ratio (B5) / (A), (B1), (B2), (B4), (B5) and (C)] multiplied by the (meth)acrylate group density of (B5), and

[0144] [Weight ratio (C) / (A), (B1), (B2), (B4), (B5) and (C)] multiplied by the (meth)acrylate group density of (C).

[0145] (A), (B1), (B2), (B4), (B5) and (C) can have their (meth)acrylate group densities determined by methods known in the art from 1 1H-NMR.

[0146] The equivalent ratio of [the (meth)acrylate groups provided by the polyol (B2)] / [the (meth)acrylate groups provided by components (A), (B1), (B2), (B3), (B4), (B5) and (C)] is preferably in the range of 0.30 / 1.00 to 1.00 / 1.00, more preferably in the range of 0.50 / 1.00 to 1.00 / 1.00, even more preferably in the range of 0.70 / 1.00 to 1.00 / 1.00 and most preferably in the range of 0.80 / 1.00 to 1.00 / 1.00.

[0147] The at least one polyurethane (PU) carrying (meth)acrylate groups and COOH groups (wherein these COOH groups are at least partially in the form of their salt groups) is preferably obtainable by the reaction of

[0148] at least one polyisocyanate (A) in an amount of 5.0% to 80.0% by weight,

[0149] at least one polyol (B1) carrying at least one COOH group in an amount of 0.5% to 30.0% by weight,

[0150] 5.0% to 80.0% of at least one polyol (B2) which carries at least one (meth)acrylate group but no COOH group and contains at least one aromatic ring,

[0151] 1.0% to 30.0% of at least one polyol (B3) which is an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, or is derived from an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, wherein the polyol has a hydroxyl value in the range of 10 to 250 and does not carry COOH groups and (meth)acrylate groups and does not contain at least one aromatic ring,

[0152] 0% to 50.0% of at least one monohydric alcohol (B4) which carries at least one (meth)acrylate group and no COOH group, and

[0153] 0% to 50.0% of at least one compound, oligomer or polymer (B5) which carries at least one OH group and is different from B1, B2 and B3 and B4,

[0154] 0% to 30.0% of at least one compound (C) which carries at least one NH2 group and no OH group

[0155] in each case based on the sum of the weights of (A), (B1), (B2), (B3), (B4), (B5) and (C1).

[0156] The at least one polyurethane (PU) carrying (meth)acrylate groups and COOH groups (wherein these COOH groups are at least partially in the form of their salt groups) is more preferably obtainable by the reaction of

[0157] at least one polyisocyanate (A) in an amount of 10.0% to 60.0% by weight,

[0158] at least one polyol (B1) carrying at least one COOH group in an amount of 1.0% to 20.0% by weight,

[0159] at least one polyol (B2) in an amount of 10.0% to 60.0% which carries at least one (meth)acrylate group but no COOH group and contains at least one aromatic ring,

[0160] at least one polyol (B3) in an amount of 3.0% to 20.0% which is an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, or is derived from an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, wherein the polyol has a hydroxyl value in the range from 10 to 250 and carries no COOH group and no (meth)acrylate group and does not contain at least one aromatic ring,

[0161] at least one monohydric alcohol (B4) in an amount of 0% to 30.0% which carries at least one (meth)acrylate group and no COOH group, and

[0162] at least one compound, oligomer or polymer (B5) in an amount of 0% to 30.0% which carries at least one OH group and is different from B1, B2 and B3 and B4,

[0163] at least one compound (C) in an amount of 0% to 15.0% which carries at least one NH2 group and no OH group

[0164] in each case based on the sum of the weights of (A), (B1), (B2), (B3), (B4), (B5) and (C1).

[0165] The at least one polyurethane (PU) carrying (meth)acrylate groups and COOH groups (wherein these COOH groups are at least partially in the form of their salt groups) is most preferably obtainable by the reaction of

[0166] at least one polyisocyanate (A) in an amount of 20.0% to 50.0% by weight,

[0167] From 1.0% to 10.0% by weight of at least one polyol (B1) carrying at least one COOH group,

[0168] From 10.0% to 60.0% of at least one polyol (B2) which carries at least one (meth)acrylate group but no COOH group and contains at least one aromatic ring,

[0169] From 5.0% to 15.0% of at least one polyol (B3) which is an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, or is derived from an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, where the polyol has a hydroxyl value in the range from 10 to 250 and carries no COOH group and no (meth)acrylate group and does not contain at least one aromatic ring,

[0170] From 0% to 15.0% of at least one monohydric alcohol (B4) which carries at least one (meth)acrylate group and no COOH group, and

[0171] From 0% to 15.0% of at least one compound, oligomer or polymer (B5) which carries at least one OH group and is different from B1, B2, B3 and B4,

[0172] From 0% to 10.0% of at least one compound (C) which carries at least one NH2 group and no OH group

[0173] In each case based on the total weight of (A), (B1), (B2), (B3), (B4), (B5) and (C1).

[0174] The equivalent ratio of the NCO groups of the polyisocyanate (A) to the OH groups of the components (B1), (B2), (B3), (B4) and (B5) can be in the range from 0.80 / 1.00 to 1.50 / 1.00, preferably the equivalent ratio is in the range from 0.90 / 1.00 to 1.30 / 1.00, and more preferably the equivalent ratio is in the range from 1.00 / 1.00 to 1.20 / 1.00.

[0175] The compound (1) carrying at least one ethylenically unsaturated group and no COOH group preferably also carries no NCO group or groups reactive towards NCO.

[0176] Examples of groups reactive towards NCO groups are OH, SH, NH2 and NH groups.

[0177] The compound (1) is generally referred to as a "reactive diluent".

[0178] Compound (1) preferably has a number average molecular weight of less than 1000 g / mol. The number average molecular weight can be determined by gel permeation chromatography calibrated with polystyrene standards.

[0179] Compound (1) preferably has a boiling point of more than 200 °C at 101325 Pa (standard pressure).

[0180] Compound (1) preferably has a melting point of less than 0 °C at 101325 Pa (standard pressure).

[0181] The functionality of the ethylenically unsaturated groups of compound (1) is generally in the range of 0.8 to 6.5, preferably in the range of 0.8 to 4.4 and more preferably in the range of 1.8 to 4.4.

[0182] The functionality of the ethylenically unsaturated groups of compound (1) can be calculated by multiplying the density of the ethylenically unsaturated groups of compound (1) by the number average molecular weight of compound (1). The density of the ethylenically unsaturated groups of compound (1) can be determined by 1 HNMR by methods known in the art.

[0183] Examples of compound (1) are styrene, p-tert-butylstyrene, p-methylstyrene, o-methylstyrene, 2-vinylnaphthalene, divinylbenzene, butadiene, isoprene, chloroprene, ethylene, propylene, 1-butene, 2-butene, isobutene, cyclopentene, cyclohexene, cyclododecene, vinyl acetate, vinyl propionate, vinyl chloride and vinylidene chloride, N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylformamide, N-vinyl-N-methyl-acetamide, N-vinylpyrrolidone, N-vinylcaprolactam, ethylene glycol divinyl ether, di(ethylene glycol) divinyl ether, tri(ethylene glycol) divinyl ether, trimethylolpropane trivinyl ether, 1,4-cyclohexanedimethanol divinyl ether, methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, isobutyl vinyl ether, tert-amyl vinyl ether, dodecyl vinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, cyclohexyl vinyl ether, allyl acetate, diallyl phthalate, triallyl cyanurate, trimethylolpropane triallyl ether, α,β-unsaturated C 4-10 -dicarboxylic acids (such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid and 2-methylenepentanedioic acid) and their salts, α,β-unsaturated C 4-10- esters of dicarboxylic acids (such as dimethyl maleate, ethyl methyl maleate, diethyl maleate, dimethyl fumarate, ethyl methyl fumarate and diethyl fumarate), α,β-unsaturated nitriles (such as (meth)acrylonitrile) and α,β-unsaturated aldehydes (such as (meth)acrolein) and α,β-unsaturated amides (such as (meth)acrylamide), α,β-unsaturated C 3-8 - carboxylic acids (such as acrylic acid, methacrylic acid and 3,3-dimethylacrylic acid) and their salts.

[0184] Further examples of compound (1) are compounds carrying at least one (meth)acrylate group, such as compounds carrying at least one (meth)acrylate group and compounds carrying at least two (meth)acrylate groups.

[0185] Examples of compounds carrying one (meth)acrylate group are C 1-20 - alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, 2-methylbutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-propylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate and dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate and nonadecyl (meth)acrylate, C 5-12 - cycloalkyl (meth)acrylates such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate and cycloheptyl (meth)acrylate, (meth)acryloyloxy(C 2-6 - alkyl) esters such as acetoacetoxyethyl (meth)acrylate, acetoacetoxypropyl (meth)acrylate and acetoacetoxybutyl (meth)acrylate, (meth)acrylic acid [C 1-10 - alkoxy(C 1-10 - alkoxy) 0-5 C 1-10-alkyl esters such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, 2-(2'-methoxyethoxy)ethyl (meth)acrylate and 2-(2'-ethoxyethoxy)ethyl (meth)acrylate, 2-norbornanyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, 4-tetrahydropyranyl (meth)acrylate, 2-tetrahydropyranyl (meth)acrylate and tetrahydrofuranyl (meth)acrylate.

[0186] Examples of compounds carrying two (meth)acrylate groups are C 1-20 -diols and diesters of (meth)acrylic acid such as 1,2-ethanediol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,2-butanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-bis(hydroxymethyl)-cyclohexane di(meth)acrylate, 1,4-bis(hydroxymethyl)-cyclohexane di(meth)acrylate and cyclohexane-1,4-diol di(meth)acrylate, ethoxylated and / or propoxylated C 1-20 -diols and diesters of (meth)acrylic acid esters such as ethoxylated and / or propoxylated 1,2-butanediol di(meth)acrylate, ethoxylated and / or propoxylated 1,4-butanediol di(meth)acrylate, ethoxylated and / or propoxylated neopentyl glycol di(meth)acrylate, ethoxylated and / or propoxylated 1,4-bis(hydroxymethyl)-cyclohexane di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate and polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polyethylene glycol-polypropylene glycol di(meth)acrylate (the order of ethylene oxide or propylene oxide units is block or random), polytetramethylene glycol di(meth)acrylate, polytetrahydrofuran di(meth)acrylate and ethoxylated or propoxylated bisphenol A di(meth)acrylate.

[0187] Examples of compounds carrying at least three (meth)acrylate groups are glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, bis(trimethylolpropane) tetra(meth)acrylate and dipentaerythritol hexa(meth)acrylate, ethoxylated and / or propoxylated glycerol tri(meth)acrylate, ethoxylated and / or propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated and / or propoxylated pentaerythritol tetra(meth)acrylate, ethoxylated and / or propoxylated bis(trimethylolpropane) tetra(meth)acrylate and ethoxylated and / or propoxylated dipentaerythritol hexa(meth)acrylate.

[0188] Preferred compound (1) is a compound carrying at least one (meth)acrylate group. More preferred compound (1) is a compound carrying at least two (meth)acrylate groups.

[0189] The composition of the present invention may further comprise a polymerization inhibitor.

[0190] Examples of polymerization inhibitors are 2,2,6,6 - tetramethylpiperidine - 1 - oxyl (TEMPO), 4 - hydroxy - 2,2,6,6 - tetramethylpiperidine - 1 - oxyl (TEMPOL), 4 - benzoyloxy - 2,2,6,6 - tetramethylpiperidine - 1 - oxyl, 4 - benzyloxy - 2,2,6,6 - tetramethylpiperidine - 1 - oxyl, 2,2 - diphenyl - 1 - picrylhydrazyl (DPPH), tris(p - nitrophenyl)methane, p - phenylenediamines such as N,N'-diphenyl - p - phenylenediamine, phenothiazine, hydroxylamines such as N,N - diethylhydroxylamine (DEHA), quinones such as hydroquinone (HQ), hydroquinone monomethyl ether, 1,4 - benzoquinone, tert - butylhydroquinone, 2,5 - bis(1,1,3,3 - tetramethylbutyl)hydroquinone, 2,5 - bis(1,1 - dimethylbutyl)hydroquinone, p - tert - butylcatechol (TBC) and 4 - methoxyphenol (MEHQ), alkylated phenols such as 2,6 - di - tert - butylphenol, 2,4 - di - tert - butylphenol, 2,4,6 - tri - tert - butylphenol, 2 - tert - butyl - 4,6 - dimethylphenol and 2,6 - di - tert - butyl - 4 - methylphenol.

[0191] The composition of the present invention generally comprises polyurethane (PU) in the range of 10% to 70% by weight, more preferably in the range of 20% to 60% by weight, even more preferably in the range of 30% to 50% by weight, and most preferably in the range of 33% to 45% by weight based on the weight of the composition.

[0192] The compositions of the present invention generally comprise water in the range of from 30% to 90% by weight, more preferably in the range of from 80% to 40% by weight, even more preferably in the range of from 70% to 50% by weight, and most preferably in the range of from 67% to 55% by weight, based on the weight of the composition.

[0193] The compositions of the present invention generally comprise less than 10% by weight, more preferably less than 5% by weight, of an organic solvent, based on the weight of the composition.

[0194] The compositions of the present invention may comprise compound (1) in the range of from 0% to 50% by weight, more preferably in the range of from 0% to 30% by weight, even more preferably in the range of from 0% to 20% by weight, and most preferably in the range of from 1% to 10% by weight, based on the weight of the composition.

[0195] The weight ratio of PU / compound (1) is generally in the range of from 0.60 / 1.00 to 20.00 / 1.00, preferably in the range of from 1.00 / 1.00 to 15.00 / 1.00, more preferably in the range of from 4.00 / 1.00 to 10.00 / 1.00.

[0196] The compositions of the present invention may comprise a polymerization inhibitor in the range of from 0.001% to 5.000% by weight, more preferably in the range of from 0.005% to 2.000% by weight, and even more preferably in the range of from 0.010% to 1.000% by weight, based on the weight of the polyurethane (PU).

[0197] The compositions of the present invention may be a dispersion or a solution. Examples of dispersions are emulsions (a liquid phase dispersed in a liquid phase) and suspensions (a solid phase dispersed in a liquid phase).

[0198] The compositions of the present invention are preferably a dispersion, more preferably a dispersion having an average particle size in the range of from 10 to 200 nm, more preferably in the range of from 30 to 150 nm, and most preferably from 40 to 130 nm. The average particle size is determined using dynamic light scattering (DLS) ISO 22412, 2017.

[0199] Another part of the present invention is a method for preparing the compositions of the present invention, the method comprising the following steps

[0200] (i) reacting at least one polyisocyanate (A),

[0201] at least one polyol (B1) carrying at least one COOH group,

[0202] At least one polyol (B2) which carries at least one (meth)acrylate group but does not carry a COOH group and contains at least one aromatic ring,

[0203] At least one polyol (B3) which is an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, or is derived from an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, wherein the polyol has a hydroxyl value in the range of 10 to 250, and does not carry a COOH group and a (meth)acrylate group and does not contain at least one aromatic ring,

[0204] Optionally at least one monohydric alcohol (B4) which carries at least one (meth)acrylate group and does not carry a COOH group, and

[0205] Optionally at least one compound, oligomer or polymer (B5) which carries at least one OH group and is different from B1, B2, B3 and B4,

[0206] React in the presence of at least one organic solvent

[0207] (ii) Optionally react the composition obtained in step (i) with at least one compound (C) which carries at least one NH2 group and does not carry an OH group

[0208] (iii) React at least a part of the COOH groups of the polyurethane of the composition obtained in step (i) or (ii) with a base

[0209] (iv) Optionally react the composition obtained in step (iii) with at least one compound (C) which carries at least one NH2 group and does not carry an OH group

[0210] (v) Add water to the composition obtained in step (iv) and remove the at least one organic solvent to obtain the composition of the present invention,

[0211] wherein the equivalent ratio of the OH groups of B2 to the OH groups of B1, B2, B3, B4 and B5 is at least 45%, and wherein the weight ratio of B3 / (A, B1, B2, B3, B4, B5 and C) is at least 1%.

[0212] The organic solvent in step (i) can be an aliphatic ketone such as acetone, ethyl methyl ketone (2-butanone) or isobutyl methyl ketone, an aliphatic amide such as N-methylpyrrolidone or N-ethylpyrrolidone, an ether such as tetrahydrofuran, dipropylene glycol dimethyl ether or dioxane, a hydrocarbon such as n-heptane, cyclohexane, toluene, o-xylene, m-xylene, p-xylene and a xylene isomer mixture, an ester such as butyl acetate, an acid such as acetic acid, or a nitrile such as acetonitrile, or a mixture thereof.

[0213] The at least one organic solvent is preferably an aliphatic ketone, and more preferably an aliphatic ketone selected from the group consisting of acetone and ethyl methyl ketone (2-butanone).

[0214] Step (i) is generally carried out in the presence of a polymerization inhibitor.

[0215] Step (i) can be carried out in the presence of at least one catalyst.

[0216] Examples of the catalyst are an amine catalyst carrying at least one tertiary amino group and an organometallic catalyst.

[0217] Examples of the amine catalyst carrying at least one tertiary amino group are 1,4-diazabicyclo[2.2.2]octane, N-methylmorpholine, N-methylimidazole, bis[2-(N,N-dimethylamino)ethyl]ether, 2,2'-dimorpholinodiethylether, and tetramethylethylenediamine, dimethylcyclohexylamine, dimethylbenzylamine, dimethylethanolamine, and dimethylaminopropylamine.

[0218] Examples of the organometallic catalyst are an organotitanium catalyst, an organotin catalyst, an organozinc catalyst, an organobismuth catalyst, an organozirconium catalyst, an organoiron catalyst, an organoaluminum catalyst, an organomanganese catalyst, an organonickel catalyst, an organocobalt catalyst, an organomolybdenum catalyst, an organotungsten catalyst, and an organovanadium catalyst.

[0219] Examples of the organotitanium catalyst are titanium(IV) tetraisopropoxide and titanium(IV) tetrabutoxide. Examples of the organotin catalyst are tin(II) diacetate, tin(II) bis(2-ethylhexanoate), tin(II) dilaurate, dimethyltin(IV) diacetate, dibutyltin(IV) diacetate, dibutyltin(IV) dibutyrate, dibutyltin bis(2-ethylhexanoate), dibutyltin(IV) dilaurate, dioctyltin(IV) dilaurate, dioctyltin(IV) diacetate, dibutyltin(IV) oxide, diphenyltin(IV) oxide, dibutyltin(IV) dichloride, and dibutyltin(IV) maleate. Examples of the organozinc catalyst are zinc(II) diacetate, zinc(II) bis(2-ethylhexanoate), and zinc(II) dineodecanoate. Examples of the organobismuth catalyst are bismuth(II) diacetate, bismuth(II) dipivalate, bismuth(II) bis(2-ethylhexanoate), bismuth(II) dineodecanoate, and bismuth(III) tris(neodecanoate). Examples of the organozirconium catalyst are zirconium(IV) tetra(acetylacetonate) and zirconium(IV) tetra(2,2,6,6-tetramethyl-3,5-heptanedionate).

[0220] Step (i) is generally carried out at a high temperature, such as at a temperature in the range of 50°C to 150°C, preferably in the range of 50°C to 100°C, more preferably in the range of 50°C to 90°C.

[0221] When an NCO content of less than 2% by weight, based on the weight of the reaction mixture, is reached by adding at least one organic solvent, which may be the same as or different from the organic solvent of step (i), step (i) is usually stopped.

[0222] The equivalent ratio of the NCO groups of the polyisocyanate (A) to the OH groups of the components (B1), (B2), (B3), (B4) and (B5) can be in the range from 0.80 / 1.00 to 1.50 / 1.00, preferably the equivalent ratio is in the range from 0.90 / 1.00 to 1.30 / 1.00, and more preferably the equivalent ratio is in the range from 1.00 / 1.00 to 1.20 / 1.00.

[0223] Steps (ii) and (iv), if carried out, are usually carried out at a temperature below 80 °C.

[0224] The base used in step (iii) can be any base. Examples of bases are given above.

[0225] In a preferred embodiment, the base is a compound carrying at least one tertiary amino group.

[0226] Step (v) is usually carried out with rapid stirring of the composition.

[0227] If compound (1) is present in the composition of the invention, step (i) can be carried out in the presence of compound (1). Compound (1) can also be added after step (i), for example, between step (i) and step (ii) or between step (iv) and step (v). A part of compound (1) can also be added in step (i) and another part of compound (1) can be added later.

[0228] Another part of the invention is an aqueous coating composition comprising the composition of the invention, the coating composition comprising a polyurethane (PU), at least one additive, optionally at least one initiator and optionally at least one polymer (2) different from the polyurethane (PU), wherein the coating composition comprises from 10% to 70% by weight of polyurethane (PU), based on the weight of the coating composition.

[0229] The additive can be any suitable additive.

[0230] Examples of additives are thickeners, UV absorbers, light stabilizers, surfactants, polymerization inhibitors, photosensitizers, curing catalysts, defoamers, plasticizers, fillers, pigments, dyes, flow control agents, antioxidants, flame retardants, antistatic agents, thixotropic agents, leveling agents, tackifiers, chelating agents, matting agents and compatibilizers.

[0231] Examples of thickeners are hydroxymethylcellulose and bentonite. Examples of ultraviolet absorbers are benzotriazoles such as 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, and 2-(2H-benzotriazol-2-yl)-p-cresol, triazines such as 2-(4,6-diphenyl-1,3,5-triazin-2-yl)5-((hexyl)oxy)phenol), cyanoacrylates, and benzophenones. Examples of light stabilizers are hindered amine light stabilizers (HALS) such as 2,2,6,6-tetramethylpiperidine, 2,6-di-tert-butylpiperidine, and bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate. Examples of fillers are talc, diatomaceous earth, clay, aluminum silicate, magnesium silicate, calcium carbonate, calcium sulfate, barium sulfate, aluminum hydroxide, alumina, and organic fillers such as polyacrylic acid and cellulose. Examples of chelating agents are ethylenediaminetetraacetic acid and β-diketone.

[0232] Initiators are compounds that form free radicals upon heat treatment (thermal free radical initiators) or radiation (photoinitiators).

[0233] Examples of thermal free radical initiators are peroxides such as potassium persulfate, benzoyl peroxide, cyclohexanone peroxide, di-tert-butyl peroxide, acetylcyclohexylsulfonyl peroxide, diisopropyl percarbonate, tert-butyl peroctoate, cumene hydroperoxide, dicumyl peroxide, and tert-butyl perbenzoate, azobisisobutyronitrile, and benzoin.

[0234] Examples of photoinitiators are acetophenone, 2,2 - dimethoxy - 2 - phenylacetophenone (benzil dimethyl ketal), 2,2 - diethoxyacetophenone, 4 - dimethylaminoacetophenone, benzophenone, 2,4,6 - trimethylbenzophenone, 4 - methylbenzophenone, 4 - hydroxybenzophenone, 4 - phenylbenzophenone, 2 - chlorobenzophenone, 4,4` - bis(diethylamino)benzophenone, thioxanthone, isopropyl - 9H - thioxanthen - 9 - one, methyl phenylglyoxylate, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin n - propyl ether, benzoin isopropyl ether, benzoin n - butyl ether, benzoin isobutyl ether, benzoin dimethyl ketal, cyclohexyl phenyl ketone, 1 - hydroxycyclohexyl phenyl ketone, p - isopropyl - 2 - hydroxyisobutyrophenone, 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone, oligo[2 - hydroxy - 2 - methyl - 1 - [4 - (1 - methylethenyl)phenyl]propanone], 2 - benzyl - 2 - dimethylamino 1 - (4 - morpholinophenyl)butan - 1 - one, 2 - benzyl - 2 - dimethylamino - 1 - (4 - morpholinophenyl) - 1 - butanone, 2 - methyl - 1 - (4 - methylthienyl) - 2 - morpholinopropan - 1 - one, 4 - (2 - hydroxyethoxy)phenyl 2 - hydroxy - 2 - propyl ketone, acylphosphine oxides (such as diphenyl(2,4,6 - trimethylbenzoyl)phosphine oxide, phenylbis(2,4,6 - trimethylbenzoyl)phosphine oxide and bis(2,6 - dimethoxybenzoyl) - 2,4,4 - trimethylpentylphosphine oxide), methyl - 2 - benzoylbenzoate and ethyl phenyl(2,4,6 - trimethylbenzoyl)phosphinate.

[0235] Mixtures of initiators can also be used. Examples of mixtures of initiators are mixtures of at least two photoinitiators, mixtures of at least one photoinitiator and at least one thermal radical initiator, and mixtures of at least two thermal radical initiators.

[0236] Common mixtures of photoinitiators are mixtures of bis(2,6 - dimethoxybenzoyl) - 2,4,4 - trimethylpentylphosphine oxide and 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone, mixtures of 1 - hydroxycyclohexyl phenyl ketone and benzophenone, mixtures of bis(2,6 - dimethoxybenzoyl) - 2,4,4 - trimethylpentylphosphine oxide and 1 - hydroxy - cyclohexyl phenyl ketone, mixtures of diphenyl(2,4,6 - trimethylbenzoyl)phosphine oxide and 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone, mixtures of 2,4,6 - trimethylbenzophenone and 4 - methylbenzophenone, and mixtures of 4 - methylbenzophenone and diphenyl(2,4,6 - trimethylbenzoyl)phosphine oxide.

[0237] The at least one initiator is preferably a photoinitiator, more preferably a UV photoinitiator. A UV photoinitiator is an initiator that forms free radicals upon UV radiation treatment. Preferred initiators are selected from the group consisting of: diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethylphenyl(2,4,6-trimethylbenzoyl)phosphinate, benzophenone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxy-cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,2-dimethoxy-2-phenylacetophenone (benzil dimethyl ketal).

[0238] Polymer (2) can be any polymer different from polyurethane (PU). Polymer (2) can be a polymer carrying ethylenically unsaturated groups or a polymer not carrying ethylenically unsaturated groups. Examples of polymer (2) are polyurethane, acrylic polymer, a mixture of polyurethane and acrylic polymer, polyester, polyether, polycarbonate, epoxy resin, alkyd resin, polyolefin, and polyvinyl acetate, and their acrylated or methacrylated derivatives.

[0239] If polymer (2) is a polymer not carrying ethylenically unsaturated groups, the hydroxyl value of polymer (2) is preferably in the range of 1 to 300 mg KOH / g, and the acid value is preferably less than 50 mg KOH / g.

[0240] Acrylated and methacrylated derivatives can be prepared by methods known in the art, for example, by esterifying the OH-groups of polyester, acrylic polymer, and polyether with acrylic acid or methacrylic acid, or by ring-opening the epoxy groups of epoxy resin with acrylic acid or methacrylic acid.

[0241] Polyurethane is a polymer containing urethane linkages. Polyurethane is typically obtained by the reaction of a diol with a diisocyanate. The diol can be a polyester diol, an acrylic polymer diol, a polycarbonate diol, or a polyether diol. Polyurethane can contain additional linking groups in the main chain in a number less than the number of urethane groups, such as ester, ether, thioether, or urethane linkages. Acrylated or methacrylated alcohols or diols can also be used as synthetic components to obtain acrylated or methacrylated polyurethane.

[0242] Acrylic polymers are generally obtained by free radical polymerization of polymerizable unsaturated monomers containing acrylate or methacrylate and optionally other polymerizable unsaturated monomers by methods known in the art, such as emulsion polymerization. Examples of other polymerizable unsaturated monomers are polymerizable unsaturated monomers carrying an OH group such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and (meth)allyl alcohol, and polymerizable unsaturated monomers carrying an acidic group such as acrylic acid, methacrylic acid, maleic acid, citraconic acid, itaconic acid, maleic anhydride, citraconic anhydride, and itaconic anhydride. Preferably, the polymerizable unsaturated monomers further include polymerizable unsaturated monomers carrying an OH group. The hydroxyl value of the acrylic polymer is preferably in the range of 1 to 200 mg KOH / g, more preferably in the range of 2 to 100 mg KOH / g, and most preferably 3 to 50 mg KOH / g. The weight average molecular weight of the acrylic polymer is preferably 1000 to 200000 g / mol, more preferably 2000 to 100000 g / mol, and most preferably 3000 to 50000 g / mol.

[0243] For example, by preparing an acrylic polymer as described above, but in the presence of a polyurethane, a mixture of the polyurethane and the acrylic polymer can be obtained.

[0244] A polyester is a polymer containing monomers linked via ester linkages. Polyesters are generally obtained by the esterification reaction or transesterification reaction of a component carrying two acidic groups and a diol. The polyester may contain linking groups other than ester groups in a number less than or equal to the number of ester groups, such as carbonate, ether, thioether, or urethane linking groups. The hydroxyl value of the polyester is preferably about 1 to 300 mg KOH / g, more preferably about 50 to 250 mg KOH / g, and still more preferably about 80 to 180 mg KOH / g. The acid value of the polyester resin is preferably about 1 to 200 mg KOH / g, more preferably about 15 to 100 mg KOH / g, and still more preferably less than 50 mg KOH / g. The weight average molecular weight of the polyester is preferably 500 to 500000 g / mol, more preferably 1000 to 300000 g / mol, and still more preferably 1500 to 200000 g / mol.

[0245] A polyether is a polymer containing ether linkages. Polyesters are generally prepared by the acid-catalyzed polymerization of an ether (such as ethylene oxide, propylene oxide, butylene oxide, or tetrahydrofuran) using an alcohol. Examples of polyethers are polyoxyethylene polyethers, polyoxypropylene polyethers, polyoxybutylene polyethers, and polytetrahydrofuran. The polyether may contain additional linking groups in the main chain in a number less than the number of ether groups, such as ester, carbonate, thioether, or urethane linkages.

[0246] Polycarbonate is a polymer containing carbonate linking groups. Polycarbonate is usually obtained by the reaction of carbonate with diol. Polycarbonate may contain additional linking groups in the main chain in a number less than the number of carbonate groups, such as ester, ether, thioether or urethane linking groups.

[0247] Epoxy resin is a polymer carrying epoxy groups. Epoxy polymers can be obtained by reacting polyol with epichlorohydrin and then dehydrohalogenating. Examples of polyols are bisphenol A, bisphenol F and novolac resins (which are polymers formed by the reaction of phenol and formaldehyde).

[0248] Alkyd resin is a polyester carrying fatty acid-derived groups. Alkyd resins are usually obtained by the esterification reaction or transesterification reaction of a component carrying two acidic groups, polyol and triglyceride fatty acid esters. Examples of the component carrying two acidic groups are phthalic anhydride and maleic anhydride. Examples of polyols are trimethylolpropane, glycerol and pentaerythritol. Examples of triglyceride fatty acid esters are soybean oil, linseed oil and coconut oil.

[0249] Polyolefin is a polymer obtainable by polymerizing at least one olefin monomer, optionally in the presence of at least one polymerizable unsaturated monomer that is not an olefin monomer, by methods known in the art such as emulsion polymerization. Olefin monomers are monomers containing only H and C atoms. Examples of olefin monomers are ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-decene and 1-dodecene; conjugated dienes and non-conjugated dienes such as butadiene, ethylidene norbornene, dicyclopentadiene and 1,5-hexadiene and styrene. Examples of polymerizable unsaturated monomers that are not olefin monomers are vinyl acetate, vinyl alcohol, maleic acid, citraconic acid, itaconic acid, maleic anhydride, citraconic anhydride and itaconic anhydride.

[0250] Preferred polymer (2) is selected from the group consisting of: polyurethane, acrylic polymer, a mixture of polyurethane and acrylic polymer, and acrylic esterified or methacrylic esterified derivatives thereof.

[0251] The coating composition of the present invention usually contains polyurethane (PU) in the range of 10% to 70% by weight based on the coating composition, more preferably in the range of 15% to 50% by weight based on the weight of the coating composition, and most preferably in the range of 20% to 45% by weight based on the weight of the coating composition.

[0252] The coating composition of the present invention usually contains additives in the range of 0.05% to 40% by weight based on the coating composition, and most preferably in the range of 0.1% to 25% by weight based on the weight of the coating composition.

[0253] The coating composition of the present invention preferably comprises at least one initiator in the range of 0.05% to 12.0% by weight, more preferably in the range of 0.1% to 10.0% by weight based on the weight of polyurethane (PU).

[0254] The coating composition of the present invention generally comprises compound (1) in the range of 0% to 20% by weight, more preferably in the range of 0.5% to 15% by weight, and most preferably in the range of 1% to 10% by weight based on the coating composition.

[0255] The coating composition of the present invention generally comprises polymer (2) in the range of 0% to 50% by weight, more preferably in the range of 0% to 25% by weight, and most preferably in the range of 0% to 10% by weight based on the coating composition.

[0256] The coating composition of the present invention generally comprises at least 20% by weight, more preferably at least 40% by weight of water based on the weight of the coating composition.

[0257] The coating composition of the present invention may further comprise an organic solvent. Examples of the organic solvent are butyl ethylene glycol, butyl diethylene glycol, methoxypropanol, 2-butoxyethyl acetate, propylene carbonate, dipropylene glycol methyl ether, propylene glycol n-butyl ether, and dipropylene glycol n-butyl ether.

[0258] The coating composition of the present invention generally comprises an organic solvent in an amount less than 10% by weight based on the weight of the coating composition.

[0259] The coating composition may be a dispersion or a solution. Preferably, the coating composition is a dispersion.

[0260] In a preferred embodiment, the coating composition of the present invention is a transparent coating composition, preferably a transparent coating composition not containing pigments.

[0261] In another preferred embodiment, the coating composition of the present invention is used as a colored coating composition.

[0262] The coating composition of the present invention can be prepared by mixing the composition of the present invention, at least one additive, optionally at least one initiator, optionally at least one polymer (2), and optionally additional water. In the mixing step, at least one additive, at least one initiator (if present), and at least one polymer (2) (if present) can be used "as is" or as a solution or dispersion in an organic solvent and / or water. In the mixing step, a polymer (2) selected from the group consisting of polyurethanes, acrylic polymers, mixtures of polyurethanes and acrylic polymers, and their acrylated or methacrylated derivatives is generally used as an aqueous solution or dispersion.

[0263] Another part of the present invention is a crosslinked layer formed from the coating composition of the present invention.

[0264] The crosslinked layer can be obtained by a method comprising the steps of: (i) applying the coating composition of the present invention to a substrate to form a layer, (ii) optionally drying the layer of step (i), and (iii) treating the layer of step (i) or step (ii) with heat, radiation, or an electron beam to form a crosslinked layer.

[0265] The coating composition of the present invention can be applied to a substrate by any method known in the art, such as by a doctor blade, spraying, spreading, knife coating, brushing, rolling, curtain coating, and lamination, a doctor blade, various printing processes such as gravure printing, transfer printing, lithographic printing, and inkjet printing, and by using a rod.

[0266] The substrate can be pretreated before applying the coating composition. For example, the substrate can be cleaned or sanded.

[0267] The layer directly obtained after applying the coating composition on the substrate preferably has a thickness in the range of 20 to 500 μm, more preferably in the range of 40 to 300 μm, most preferably in the range of 60 to 240 μm, and especially 60 to 200 μm.

[0268] The layer directly obtained after applying the coating composition on the substrate is generally referred to as a wet layer.

[0269] The layer of step (i) can be dried in step (ii) to remove at least most of the water (and other volatiles, such as organic solvents).

[0270] The layer obtained after removing at least most of the water (and other volatiles, such as organic solvents) is generally referred to as a dry layer.

[0271] Step (ii) (if present) is preferably carried out at a temperature in the range of 15 °C to 160 °C, more preferably in the range of 40 °C to 160 °C. In the case where a thermal free radical initiator is present in the coating composition, drying conditions (temperature and time) that do not activate the thermal free radical initiator are preferably selected.

[0272] In step (iii), the layer of step (i) or step (ii) is treated with electron beam, heat or radiation to form a crosslinked layer. Heat can also be applied by near-infrared (NIR) radiation (such as radiation having a wavelength in the range of 760 to 2500 nm). Preferably, the layer of step (i) or (ii) is treated with ultraviolet radiation, sunlight or electron beam. More preferably, the layer of step (i) or (ii) is treated with radiation having a wavelength in the range of 200 to 700 nm, even more preferably in the range of 200 to 500 nm, and most preferably in the range of 250 to 400 nm.

[0273] Examples of radiation sources are low-pressure mercury vapor lamps, medium-pressure mercury vapor lamps, high-pressure mercury vapor lamps, lasers, pulsed lamps (flash lamps), halogen lamps and excimer lamps. A radiation dose sufficient to effect crosslinking is generally selected. In the case of UV radiation, a radiation dose of 80 to 3000 mJ / cm 2 is typically used, preferably 100 to 2000 mJ / cm 2 . Combinations of different radiation sources can also be used.

[0274] Step (iii) can be carried out in the presence of oxygen or preferably in the absence of oxygen (such as in an inert gas atmosphere). Suitable inert gases are nitrogen, argon and carbon dioxide. The layer of step (i) or (ii) can also be covered with a transparent medium such as a transparent polymer film, glass or water, and irradiation is carried out through this transparent medium. Irradiation can also be carried out by passing the substrate coated with the layer of step (i) or (ii) through the radiation source at a constant speed.

[0275] In a preferred embodiment, step (ii) is carried out and the layer of step (ii) is treated with radiation in step (iii) to form a crosslinked layer.

[0276] Steps (i), optionally step (ii) and step (iii) can be repeated to obtain a multi-layer crosslinked layer.

[0277] The substrate can be any suitable substrate. The substrate can be a wood substrate, an engineered wood substrate, an engineered bamboo substrate, an engineered cellulose substrate other than engineered wood or engineered bamboo substrates, a fiber-reinforced composite substrate (FRC), a wood-plastic composite substrate (WPC), a plastic substrate (such as a melamine formaldehyde substrate), a paper substrate, a recycled paper substrate, a cardboard (also known as paperboard) substrate, a recycled cardboard (also known as recycled paperboard) substrate, a metal substrate, a stone substrate, a glass substrate, a textile substrate, a leather substrate, a ceramic substrate, a mineral building material substrate (such as a molded cement block and a fiber-cement board). The substrate can be pre-coated with a coating composition different from the coating composition of the present invention. Preferably, the substrate is not pre-coated with a coating composition different from the coating composition of the present invention.

[0278] Examples of wood substrates are oak, beech, maple, alder, ash, pine, fir, spruce, chestnut, locust, birch, elm, teak and walnut as well as softwood.

[0279] The wood can be in the form of, for example, sawn timber (also known as lumber), planks for floors (such as parquet), devices for house construction or household applications, or solid wood furniture. The softwood can be in the form of, for example, tiles for floors, or devices for household applications.

[0280] Engineered wood substrates are derived wood substrates manufactured by bonding or fixing strips, particles, fibers, veneers or boards of wood with adhesives or other fixing methods to form a composite material. Examples of adhesives are urea formaldehyde resin, phenolic resin, melamine formaldehyde resin, polymeric methylene diphenyl diisocyanate, polyvinyl acetate and polyurethane. Examples of engineered wood substrates are glued laminated timber, cross-laminated timber (CLT), parallel strand lumber (PSL), laminated strand lumber (LSL), laminated veneer lumber (LVL), plywood, oriented strand board (OSB), composite board, particle board (also known as chipboard or flakeboard) and fiberboard such as hardboard (also known as high density fiberboard, HDF) and medium density fiberboard (MDF).

[0281] Engineered wood substrates can be in the form of thin sheets for engineered wood floors (such as laminate floors), devices for house construction or household applications and furniture (such as flat-pack furniture).

[0282] Engineered bamboo substrates are derived bamboo substrates manufactured by bonding or fixing bamboo parts with adhesives or other fixing methods to form a composite material. Examples of engineered bamboo substrates are laminated bamboo.

[0283] Engineered cellulose substrates other than engineered wood substrates and engineered bamboo substrates are products from lignin-containing materials other than wood and bamboo (such as rye straw, wheat straw, rice straw, hemp stalks, kenaf stalks, and sugarcane bagasse), which are manufactured by bonding or fixing parts of lignin-containing materials other than wood and bamboo with adhesives or other fixing methods to form composite materials.

[0284] Fiber Reinforced Composite Substrate (FRC) is made from rice-derived fibers and plastics.

[0285] Wood-Plastic Composite (WPC) is a composite material made from wood fibers or wood flour and thermoplastic polymers (such as polyethylene, polypropylene, polyvinyl chloride, or polyacetic acid).

[0286] Preferably, the substrate is selected from the group consisting of wood substrates and plastic substrates.

[0287] Another part of the present invention is a substrate coated with the layer of the present invention.

[0288] Another part of the present invention is the use of the coating composition of the present invention as a transparent coating composition.

[0289] Another part of the present invention is the use of the coating composition of the present invention as a colored coating composition.

[0290] The compositions of the present invention, and particularly the coating compositions of the present invention, are advantageous in that these compositions form crosslinked layers on the substrate that exhibit good Martens hardness and good indentation hardness, and also form crosslinked layers on the substrate that exhibit good adhesion to the substrate.

[0291] Examples

[0292] The NCO content of the composition [weight of NCO / weight of composition] is determined as follows: First, the composition is treated with di-n-butylamine and then the unreacted di-n-butylamine is back-titrated to determine the amount of reacted di-n-butylamine. The following method can be used: Add 10 mL of a 1N solution of di-n-butylamine in xylene to 1 g of the composition to be analyzed dissolved in 100 mL of N-methylpyrrolidone. Stir the resulting mixture at room temperature for five minutes. Then, the resulting reaction mixture is back-titrated with 1N hydrochloric acid to measure the volume of hydrochloric acid required to neutralize the unreacted di-n-butylamine. This reveals how many moles of di-n-butylamine reacted with the NCO groups. The NCO content is (moles of reacted di-n-butylamine x molecular weight of NCO) / weight of the composition. The weight of the composition is 1 g. The molecular weight of NCO is 42 g / mol.

[0293] Example 1

[0294] Preparation of the aqueous polyurethane dispersion PUD-1 containing polyurethane PU-1

[0295] 41.89 g of dimethylolpropionic acid (Compound B1), 390.35 g of Laromer EA 9143 (composed of 75% by weight of bisphenol A diglycidyl ether diacrylate (Compound B2) and 25% by weight of propoxylated glycerol triacrylate with a degree of propoxylation of 3.8 (reactive diluent)), 75.36 g of ALBODRY castor oil low moisture 1500 (OH value: 160 - 168 mg KOH / g, iodine value: 81 - 91 g / 100 g) (Compound B3), 41.64 g of Alberdingk OP 100 (urethane-modified linseed oil-based polymer, 100% solids, OH value: 7 mg KOH / g) (Compound B5), 0.077 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy (4-hydroxy-TEMPO) and 0.54 g 315 (OMG Borchers, bismuth(III) neodecanoate) was weighed into a stirring vessel. The precharge was dissolved in 229.4 g of methyl ethyl ketone and heated to 60 °C. A mixture of 185.12 g of isophorone diisocyanate (Compound A) and 36.26 g of Lupranat T80 A (composed of 80% by weight of toluene-2,4-diisocyanate and 20% by weight of toluene-2,6-diisocyanate) (Compound A) was added in four equal portions over 5 min, with a 15-min waiting time between each addition. The progress of the reaction was monitored by measuring the residual NCO. When the level of residual NCO content was < 1.1% by weight (based on the reaction mixture), the reaction mixture was further diluted by adding 300 g of acetone. The obtained mixture was neutralized by adding 31.64 g of triethylamine and dispersed in 1050 g of deionized water with vigorous stirring. After distilling off the solvent mixture and diluting with an additional 200 g of deionized water, an aqueous composition PUD-1 containing polyurethane PU-1 was obtained, which had a solids content of 37.8% by weight and the properties shown in Table 1.

[0296] Example 2

[0297] Preparation of aqueous polyurethane dispersion PUD-2 containing polyurethane PU-2

[0298] 42.14 g of dimethylolpropionic acid (Compound B1), 389.26 g of Laromer EA 9143 (composed of 75% by weight of bisphenol A diglycidyl ether diacrylate (Compound B2) and 25% by weight of propoxylated glycerol triacrylate with a degree of propoxylation of 3.8 (reactive diluent)), 74.6 g of hydrogenated castor oil (OH value: 157 mg KOH / g, iodine value: 2.1 I2 g / 100 g) (Compound B3), 41.89 g of Alberdingk OP 100 (urethane-modified linseed oil-based polymer, 100% solids, OH value: 7 mg KOH / g) (Compound B5), 0.077 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-hydroxy-TEMPO) and 0.54 g 315 (OMG Borchers, bismuth(III) neodecanoate) was weighed into a stirring vessel. The pre-charge was dissolved in 229.4 g of methyl ethyl ketone and heated to 60 °C. A mixture of 186.2 g of isophorone diisocyanate (Compound A) and 36.48 g of Lupranat T80 A (composed of 80% by weight of toluene-2,4-diisocyanate and 20% by weight of toluene-2,6-diisocyanate) (Compound A) was added in four equal portions over 5 min, with a waiting time of 15 min between each addition. The progress of the reaction was monitored by measuring the residual NCO. When the level of residual NCO was < 1.1% by weight (based on the reaction mixture), the reaction mixture was further diluted by adding 300 g of acetone. The resulting mixture was neutralized by adding 31.83 g of triethylamine and dispersed in 1050 g of deionized water with vigorous stirring. After distilling off the solvent mixture and diluting with an additional 200 g of deionized water, an aqueous composition PUD-2 containing polyurethane PU-2 was obtained, which had a solids content of 38.6% by weight and the properties shown in Table 1.

[0299] Comparative Example 1

[0300] Preparation of comparative aqueous polyurethane dispersion comp PUD-3 containing comparative polyurethane compPU-3

[0301] 51.42 g of dimethylolpropionic acid (Compound B1), 266.3 g of Laromer EA 9143 (consisting of 75% by weight of bisphenol A diglycidyl ether diacrylate (Compound B2) and 25% by weight of propoxylated glycerol triacrylate with a degree of propoxylation of 3.8 (reactive diluent)), 89.56 g of Albodur 921 (Alberdingk Boley) (castor oil-based OH-functional polymer, 100% solids, hydroxyl value: 218 mg KOH / g) (Compound B3), 26.98 g of hydroxyethyl acrylate (Compound B4), 31.6 g of Alberdingk OP 100 (urethane-modified linseed oil-based polymer, 100% solids, OH value: 7 mg KOH / g) (Compound B5), 0.077 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy (4-hydroxy-TEMPO) and 0.54 g 315 (OMG Borchers, bismuth(III) neodecanoate) was weighed into a stirred vessel. The precharge was dissolved in 229.4 g of methyl ethyl ketone and heated to 60 °C. 306.28 g of Desmodur W (Covestro, dicyclohexylmethane diisocyanate; NCO content ≥ 31.8% by weight) (Compound A) was added in four equal portions over 5 min with a 15 min waiting period between each addition. The progress of the reaction was monitored by measuring the residual NCO. When the level of residual NCO < 1.1% by weight (based on the reaction mixture), the reaction mixture was further diluted by adding 300 g of acetone. The resulting mixture was neutralized by adding 45.27 g of triethylamine and dispersed in 1050 g of deionized water with vigorous stirring. After distilling off the solvent mixture and diluting with an additional 400 g of deionized water, an aqueous composition compPUD-3 containing polyurethane compPU-3 was obtained, which had a solids content of 34.6% by weight and the properties shown in Table 1.

[0302] Comparative Example 2

[0303] Preparation of comparative aqueous polyurethane dispersion comp PUD-4 containing comparative polyurethane compPU-4

[0304] 32.02 g of dimethylolpropionic acid (Compound B1), 234.54 g of Laromer EA 9143 (composed of 75% by weight of bisphenol A diglycidyl ether diacrylate (Compound B2) and 25% by weight of propoxylated glycerol triacrylate with a degree of propoxylation of 3.8 (reactive diluent)), 174.74 g of dipentaerythritol pentaacrylate (Compound B4) / dipentaerythritol hexaacrylate (reactive diluent) (OHZ 46 mg KOH / g, double bond density ( 1 H-NMR) = 9.4 mol / kg), 38.47 g of Laromer EA 9101 (BASF, acrylated epoxidized soybean oil, hydroxyl value: 139 mg KOH / g, double bond density (1H-NMR): 2.0 mol / kg) (Compound B5), 0.35 g of Kerobit TBK (Alpha Aeser, 2,6-di-tert-butyl-4-methylphenol), 0.14 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy (4-hydroxy-TEMPO), 198.32 g of Desmodur W (Covestro, dicyclohexylmethane diisocyanate; NCO content ≥ 31.8 wt%) (Compound A) and 15.12 g of Basonat HI 100NG (BASF, hexamethylene diisocyanate trimer, NCO content approximately 22 wt%) (Compound A) were weighed into a stirring vessel. The precharge was dissolved in 300 g of methyl ethyl ketone and heated to 60 °C. 0.49 g of 315 (OMG Borchers, bismuth(III) neodecanoate) was added, and the reaction mixture was further heated until a temperature of 80 °C was reached. The progress of the reaction was monitored by measuring the residual NCO. When the level of residual NCO < 1.4 wt% (based on the reaction mixture), the reaction mixture was further diluted by adding 200 g of acetone and cooled to 40 °C. 6.78 g of isophorone diamine diluted in 20 g of acetone was added over a period of 5 min. After a waiting time of 5 min, the reaction mixture was neutralized by adding 71.69 g of NaOH (10 wt%, in H2O), and dispersed in 650 g of deionized water with vigorous stirring. After 20 min, a mixture of 6.78 g of isophorone diamine and 3.25 g of diethyltriamine diluted in 50 g of deionized water was added over a period of 15 min. After distilling off the solvent mixture and diluting with an additional 400 g of deionized water, an aqueous composition compPUD-4 containing polyurethane compPU-4 was obtained, which had a solids content of 39.0 wt% and the properties shown in Table 1.

[0305] Comparative Example 3

[0306] Preparation of Comparative Aqueous Polyurethane Dispersion compPUD-5 Containing Polyurethane compPU-5

[0307] Weigh 41.51 g of dimethylolpropionic acid (Compound B1), 168.94 g of Laromer EA 9143 (composed of 75% by weight of bisphenol A diglycidyl ether diacrylate (Compound B2) and 25% by weight of propoxylated glycerol triacrylate with a propoxylation degree of 3.8 (reactive diluent)), 232.0 g of Albodur 921 (Oberdorfer GmbH) (castor oil-based OH-functional polymer, 100% solids, hydroxyl value: 218 mg KOH / g) (Compound B3), 53.91 g of hydroxyethyl acrylate (Compound B4), 0.077 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy (4-hydroxy-TEMPO) and 0.54 g 315 (OMG Borchers GmbH, bismuth(III) neodecanoate) into a stirred vessel. Dissolve the precharge in 229.4 g of methyl ethyl ketone and heat to 60 °C. Add a mixture of 229.33 g of isophorone diisocyanate (Compound A) and 44.92 g of Lupranat T80 A (composed of 80% by weight of toluene-2,4-diisocyanate and 20% by weight of toluene-2,6-diisocyanate) (Compound A) in four equal portions over 5 min, with a 15-min waiting time between each addition. Monitor the progress of the reaction by measuring the residual NCO. When the level of residual NCO < 1.1 wt.%, further dilute the reaction mixture by adding 300 g of acetone. Neutralize the resulting mixture by adding 31.35 g of triethylamine and disperse it in 1050 g of deionized water with vigorous stirring. After distilling off the solvent mixture and diluting with an additional 200 g of deionized water, an aqueous composition compPUD-5 containing polyurethane compPU-5 is obtained, which has a solids content of 38.3 wt.% and the properties shown in Table 1.

[0308] Example 3

[0309] Preparation of Transparent Coating Compositions Containing Aqueous Polyurethane Dispersions PUD-1 and PUD-2 of Examples 1 and 2, Respectively, and Preparation of Comparative Transparent Coating Compositions Containing Comparative Aqueous Polyurethane Dispersions compPUD-3, compPUD-4, and compPUD-5 of Comparative Examples 1, 2, and 3, Respectively.

[0310] The aqueous polyurethane dispersions PUD-1 and PUD-2 of Examples 1 and 2 respectively, and the comparative aqueous polyurethane dispersions compPUD-3, compPUD-4 and compPUD-5 of Comparative Examples 1, 2 and 3 respectively were diluted with water to a solid content of 35% by weight. 1 g 184 (photoinitiator, available from IGM Resins) was mixed with 1 g of butyl ethylene glycol (solvent). Using a high-speed mixer (2000 rpm, 2 minutes), 100 g of the diluted aqueous polyurethane dispersion (35% by weight) was mixed with 2.0 g of a 1 / 1 (weight / weight) mixture of 184 and butyl ethylene glycol (solvent) and 1.0 g of PE 1330 (thickener, available from BASF) to obtain a coating composition.

[0311] Example 4

[0312] Preparation of a transparent glass plate coated with the transparent coating composition of Example 3 and determination of the indentation hardness and Martens hardness of the coating layer

[0313] The coating composition of Example 3 was applied to the surface of a transparent glass plate through a box coater with a 400 μm gap to form a layer. The resulting film thickness must be at least 10 times the expected maximum indentation depth. The resulting layer was dried at room temperature for 2 minutes and then in a convection oven at 50 °C for 15 minutes. After the drying step, the layers were immediately treated by UV radiation using a Hg lamp at 50% power (2 x 10 m / min, total dose of about 1200 mJ / cm 2 to form a cured layer. Before starting to measure the hardness and flexibility of the layer with an indentation object (diamond Vickers pyramid), the cured layers were stored in a climate chamber (temperature (23 ± 2) °C, humidity (50 ± 5)%) for 24 hours, where the indentation hardness and Martens hardness were measured using a Fischerscope HM2000 S with the following parameters: F max = 500 mN, F min = 0.4 mN, t1 = t2 = t3 = t4 = 30 s.

[0314] Definition:

[0315] F max = maximum test force [mN]

[0316] t1 = application time of the test force [s]

[0317] t2 = holding time at the maximum test force [s]

[0318] F max = minimum test force [mN]

[0319] t3 = Time before retracting the test force

[0320] t4 = Holding time at the minimum test force [s]

[0321] HM(Fmax / t1 / 0) = Martens hardness [N / mm 2

[0322] HIT(Fmax / t1 / t2 / t3) = Indentation hardness [N / mm 2

[0323] Evaluation is started after two separate measurements, and the average values of Martens hardness (H M ) and indentation hardness (H IT ) are recorded.

[0324] The higher the values of Martens hardness and indentation hardness, the better the hardness.

[0325] The results are listed in Table 1.

[0326] Example 5

[0327] Preparation of white pigmented coating compositions respectively containing the aqueous polyurethane dispersions PUD-1 and PUD-2 of Example 1 and 2, and preparation of comparative white pigmented coating compositions respectively containing the comparative aqueous polyurethane dispersions compPUD-3, compPUD-4 and compPUD-5 of Comparative Examples 1, 2 and 3.

[0328] The aqueous polyurethane dispersions PUD-1 and PUD-2 of Example 1 and 2 respectively and the comparative aqueous polyurethane dispersions compPUD-3, compPUD-4 and compPUD-5 of Comparative Examples 1, 2 and 3 respectively are diluted with water to a solids content of 35 wt%.

[0329] A mixture of 21 g of Luconyl white NG 0025 (an aqueous pigment preparation available from BASF), 0.5 g of Hydropalat WE 3220 (a surfactant available from BASF), 1.2 g of Omnirad 819DW (a photoinitiator available from IGM Resins), 0.5 g of Tego Foamex 822 (an antifoaming agent available from Evonik), 1.0 g of Ultralube D-888 (a wax dispersion available from Keim Additec Surface) and 0.8 g of Omnirad 184 (a photoinitiator available from IGM Resins) in 0.8 g of butyl glycol (solvent) is mixed (using a high-speed mixer at 2750 upm for 2 min) to obtain a "paste". ​​

[0330] To incorporate the matting agent well, 30 g of an aqueous polyurethane dispersion (35 wt%) was mixed with 1.0 g of Acematt TS100 (a matting agent available from Evonik) using a high-speed mixer (2750 rpm, 3 minutes). If the incorporation of the matting agent was not good, the mixture was remixed using a high-speed mixer (2750 rpm, 1 - 2 minutes). The “Acematt TS100 dispersion” was obtained.

[0331] 53.1 g of an aqueous polyurethane dispersion (35 wt%), the “paste” obtained above, and the “Acematt TS100 dispersion” obtained above were mixed using a high-speed mixer at 2750 rpm for 2 min. 0.8 g of Tafigel PUR 44 (a thickener, available from BASF) was added to the obtained mixture and remixed using a high-speed mixer at 2750 rpm for 1 min.

[0332] Example 6

[0333] Preparation of a melamine (melamine formaldehyde) panel coated with the white colored coating composition of Example 5, and determination of the “adhesion” of the coating layer to the melamine panel

[0334] The white colored coating composition of Example 5 was applied onto the surface of the melamine panel using a 200 - micron small box coater to form a layer. These layers were dried at room temperature for 2 minutes and then dried in an oven at 50 °C for 15 minutes. After the drying step, the layers were immediately treated by UV radiation (1×10 m / min, total dose of about 1200 - 1300 mJ / cm 2 using an Hg and Ga lamp at 50% power) to form a cured layer. The first layer was sanded with 400 - grit sandpaper and wiped with a clean tissue paper (soft absorbent). Then, the procedure was repeated again, and the second layer was applied onto the first layer using a smaller box coater and dried and cured in the same manner as described for the first layer.

[0335] An adhesion test was conducted on the panel using a knife / blade with an additional template for guiding the cut (distance 2 mm). The cross - cuts were made at least 5 mm from the edge. The cutting device was placed perpendicular to the surface, and six cuts (each about 2 cm long) were made parallel to each other. Then the sample was rotated 90°, and the procedure was repeated again to obtain a grid. Then a self - adhesive tape (about 4 cm long, test number 4124) was placed on the grid, smoothed with a finger (with strong pressure) and pulled out at a 60° angle.

[0336] The cut surface was immediately evaluated and classified as follows:

[0337]

[0338] Therefore, the smaller the classification, the better the adhesion of the coating layer to the melamine panel.

[0339] The results are listed in Table 1.

[0340]

[0341] Table 1. *B is the sum of B1, B2, B3, B4 and B5.

[0342] Table 1 shows that the coating compositions of the aqueous polyurethane dispersions PUD-1 and PUD-2 of the present invention containing an equivalent ratio of OH groups of B2 of about 59% / (OH groups of B1, B2, B3, B4 and B5) and a weight ratio of B3 / (A + B* + C) of about 11% produce on a transparent glass plate crosslinked layers showing good Martens hardness of 115.2 and 116.4 N / mm 3 respectively, and good indentation hardness of 129.2 N / mm 3 and 132.7 N / mm 3 respectively, and at the same time also produce on the melamine panel crosslinked layers showing good adhesion of classification 1 to 2.

[0343] Table 1 also shows that the comparative coating composition of the aqueous polyurethane dispersion compPUD-3 containing an equivalent ratio of OH groups of B2 of only 37.9% / (

[0344] OH groups of B1, B2, B3, B4 and B5) produces on a transparent glass plate a crosslinked layer showing acceptable Martens hardness of 109.0 N / mm 3 and acceptable indentation hardness of 122.6 N / mm 3 but only produces on the melamine panel a crosslinked layer showing poor adhesion of classification 4.

[0345] Table 1 also shows that the comparative coating composition of the aqueous polyurethane dispersion compPUD-4 containing a weight ratio of B3 / (A + B* + C) of 0% produces on a transparent glass plate a crosslinked layer showing good Martens hardness of 153.8 N / mm 3 and good indentation hardness of 187.2 N / mm 3 but only produces on the melamine panel a crosslinked layer showing poor adhesion of classification 5.

[0346] Table 1 also shows that the comparative coating composition of the aqueous polyurethane dispersion compPUD-5 containing an equivalent ratio of OH groups of B2 of 20.8% / (B1, B2, B3, B4 and B5 OH groups) produces on a transparent glass plate crosslinked layers showing 72.2 N / mm3 The difference in Martens hardness and 70.1 N / mm 3 A crosslinked layer with a difference in indentation hardness, but a crosslinked layer showing good adhesion classified as 1 to 2 is produced on the melamine panel.

Claims

1. A composition comprising (i) at least one polyurethane PU carrying (meth)acrylate groups and COOH groups, at least some of these COOH groups being at least partially in the form of their salt groups, the polyurethane being obtainable by the reaction of at least one polyisocyanate (A), at least one polyol (B1) carrying at least one COOH group, at least one polyol (B2) carrying at least one (meth)acrylate group but no COOH group and containing at least one aromatic ring, at least one polyol (B3) which is an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, or derived from an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, wherein the polyol has a hydroxyl value in the range from 10 to 250 and carries no COOH group and no (meth)acrylate group and does not contain at least one aromatic ring, optionally at least one monohydric alcohol (B4) carrying at least one (meth)acrylate group and no COOH group, and optionally at least one compound, oligomer or polymer (B5) carrying at least one OH group and different from B1, B2 and B3 and B4, optionally at least one compound (C) carrying at least one NH2 group and no OH group, wherein the equivalent ratio of the OH groups of B2 to the OH groups of B1, B2, B3, B4 and B5 is at least 45%, and wherein the weight ratio of B3 / (A, B1, B2, B3, B4, B5 and C) is at least 1%, (ii) optionally at least one compound (1) carrying at least one ethylenically unsaturated group and no COOH group and (iii) water.

2. The composition according to claim 1, wherein The equivalent ratio of the OH groups of B2 to the OH groups of B1, B2, B3, B4 and B5 is at least 50%.

3. The composition according to claim 2, wherein, The equivalent ratio of the OH groups of B2 to the OH groups of B1, B2, B3, B4 and B5 is at least 55%.

4. The composition according to any one of claims 1 to 3, wherein, The weight ratio of B3 / (A, B1, B2, B3, B4, B5 and C) is in the range from 2% to 30%.

5. The composition according to any one of claims 1 to 3, wherein, The weight ratio of B3 / (A, B1, B2, B3, B4, B5 and C) is in the range from 3% to 25%.

6. The composition according to any one of claims 1 to 5, wherein The polyol (B2) has the following formula wherein L 1 is a linking group containing at least one aromatic ring.

7. The composition according to any one of claims 1 to 5, wherein, The polyol (B2) has the following formula where L 1 is selected from the group consisting of:

8. The composition according to any one of claims 1 to 5, wherein, The polyol (B2) has the following formula where L 1 is 9. The composition according to any one of claims 1 to 8, wherein The polyol (B3) is an ester of glycerol and at least one carboxylic acid carrying at least 10 and at most 21 carbon atoms, or derived from an ester of glycerol and at least one carboxylic acid carrying at least 10 and at most 21 carbon atoms, wherein the polyol has a hydroxyl value in the range from 50 to 250 and carries no COOH group and no (meth)acrylate group and does not contain at least one aromatic ring.

10. The composition according to any one of claims 1 to 9, wherein, The polyol (B3) is a triester of glycerol and ricinoleic acid, a triester of glycerol and hydrogenated ricinoleic acid, or derived from a triester of glycerol and ricinoleic acid or a triester of glycerol and hydrogenated ricinoleic acid.

11. The composition according to any one of claims 1 to 10, wherein, The at least one polyurethane (PU) carrying (meth)acrylate groups and COOH groups - where at least some of these COOH groups are in the form of their salt groups - is more preferably obtainable by the reaction of from 10.0% to 60.0% by weight of at least one polyisocyanate (A), from 1.0% to 20.0% by weight of at least one polyol (B1) carrying at least one COOH group, from 10.0% to 60.0% of at least one polyol (B2) which carries at least one (meth)acrylate group but no COOH group and contains at least one aromatic ring, from 3.0% to 20.0% of at least one polyol (B3) which is an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, or is derived from an ester of glycerol and at least one carboxylic acid carrying at least 6 carbon atoms, where the polyol has a hydroxyl value in the range from 10 to 250 and carries no COOH group and no (meth)acrylate group and contains no at least one aromatic ring, from 0% to 30.0% of at least one monohydric alcohol (B4) which carries at least one (meth)acrylate group and no COOH group, and from 0% to 30.0% of at least one compound, oligomer or polymer (B5) which carries at least one OH group and is different from B1, B2, B3 and B4, from 0% to 15.0% of at least one compound (C) which carries at least one NH2 group and no OH group in each case based on the total weight of (A), (B1), (B2), (B3), (B4), (B5) and (C1).

12. The composition according to any one of claims 1 to 11, wherein, Compound (1) carries at least one (meth)acrylate group.

13. The composition according to any one of claims 1 to 12, wherein The composition contains polyurethane (PU) in an amount from 10% to 70% by weight based on the weight of the composition.

14. An aqueous coating composition which contains a composition as claimed in any one of claims 1 to 13, at least one additive, optionally at least one initiator and optionally at least one polymer (2) different from polyurethane (PU), where the coating composition contains polyurethane (PU) in the range from 10% to 70% by weight based on the weight of the coating composition.

15. A crosslinked layer formed from the aqueous coating composition as claimed in claim 14.

16. A substrate coated with the cured layer as claimed in claim 15.

17. The substrate according to claim 16, wherein, The substrate is a plastic substrate or a wood substrate.

18. Use of the coating composition as claimed in claim 14 as a transparent coating composition.

19. Use of the coating composition as claimed in claim 14 as a colored coating composition.

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