Waterborne radiation curable compositions for soft feel applications

Abstract

An aqueous radiation curable composition comprising: a radiation curable polyurethane dispersion obtained by reacting a. a compound comprising at least two isocyanate groups; b. a polyol having a molecular weight of at least 500 g / mol; c. a compound comprising at least one group capable of reacting with an isocyanate group and at least one hydrophilic group; and d. an ethylenically unsaturated compound comprising at least one group capable of reacting with an isocyanate group and at least one ethylenically unsaturated group; a plurality of polyurethane particles having a median particle size D50 of 1 to 10 μm; and water.

Description

[Technical field]

[0001] The present invention relates to an aqueous radiation curable composition, a coating comprising said composition, a method for forming the composition, a method for forming the coating, and the use of the coating in the field of coating applications, more particularly in the field of soft feel applications, such as for example use in automotive interiors. [Background technology]

[0002] The coating protects the surface from degradation that may result from chemicals and / or abrasion. Soft-feel coatings may have the added ability to transform the sometimes unattractive tactile feel of a surface (e.g., a plastic surface) into a comfortable feel like rubber, leather, or velvet. This allows manufacturers to use relatively inexpensive materials, e.g., plastics, and apply a coating to give a high-end, luxury appearance. The coating can provide a high-quality, even luxurious appearance to the consumer. There is a growing demand for soft-feel coatings. Such coatings can be used in many applications, including consumer electronics (e.g., laptops, mobile phone casings), home appliances (e.g., ovens, coffee makers), automotive interiors (e.g., panels, holders, armrests), packaging (e.g., cosmetic bottles / caps, bags), and textured films for in-mold decoration / labeling (IMD / IML).

[0003] Current soft-feel coatings used in automobiles can be formed from conventional two-component aqueous compositions. Such soft-feel coatings typically do not have the chemical resistance that may be required, particularly against sunscreens and insect repellents (e.g., N,N-diethyl-meta-toluamide, or DEET). Instead, the required chemical resistance is provided by a primer layer that exists under the soft-feel coating. Providing a primer layer requires additional time and expense.

[0004] Solvent-based curable compositions (wherein the solvent is typically a volatile organic compound) are commercially available (e.g., commercial compositions EBECRYL® 8896 and EBECRYL® 8894). However, solvent-based compositions typically do not provide a soft touch for automotive interiors. Furthermore, the coatings formed thereby do not pass the required chemical tests, i.e., do not have the required chemical resistance.

[0005] Solvent-based curable compositions also have regulatory drawbacks, for example, the solvents are typically volatile organic compounds that are undesirable from a sustainability standpoint.

[0006] The market is currently looking for an improvement over traditional coatings due to the poor chemical and scratch resistance of existing coatings. The introduction of water-based UV technology could revolutionize the soft touch market.

[0007] Thus, there remains a need in the art for aqueous coating compositions that have good soft feel and chemical resistance. Summary of the Invention [Problem to be solved by the invention]

[0008] It is therefore an object of the present invention to develop a radiation curable composition and coatings formed therefrom that at least partially overcomes some of the above mentioned disadvantages. [Means for solving the problem]

[0009] Compositions according to embodiments of the present invention and coatings formed therefrom may have one or more of the following advantages: Embodiments of the composition are easy to apply, for example compared to state-of-the-art two-component water-based compositions. In particular, application of a primer layer to a surface prior to application of the composition to the surface may be unnecessary. Thus, the method of applying the composition may be simple and cost-effective. Sophisticated equipment, for example two-component spray guns, are typically not required for application of the composition. · Volatile organic compounds (e.g., organic solvents) are typically not required in the composition. Furthermore, the amount of unreacted, i.e., free, isocyanate groups in the composition can be small. This can make the composition a sustainable and safe choice from a regulatory standpoint. Furthermore, the absence of reactive free isocyanate groups typically extends the shelf life, i.e., pot life, of the composition. Potentially extended composition shelf life, i.e. pot life, allows larger batches to be prepared, which can result in further cost savings. The composition can have good spray viscosity. Furthermore, coatings can be formed from the composition at low temperatures. Unlike conventional water-based compositions, embodiments of the compositions of the present invention may not contain formaldehyde, alkylphenol ethoxylates (APEOs), N-methylpyrrolidone (NMPs), or N-ethylpyrrolidone (NEPs). Because the composition is radiation curable, the time required to cure the composition to form a coating may be short, e.g., on the order of seconds or less instead of hours. The composition can provide a coating with a soft feel. Additionally, the composition can provide a coating with good chemical stability and good to excellent chemical resistance, particularly to sunscreens and insect repellents, such as N,N-diethyl-meta-toluamide (DEET). The composition according to the invention is capable of providing a coating with good adhesion.

[0010] In a first aspect, the present invention relates to an aqueous radiation curable composition comprising a radiation curable aqueous polyurethane dispersion, also called radiation curable polyurethane dispersion, obtainable by reacting a. a compound comprising at least two isocyanate groups, b. a polyol having a molecular weight of at least 500 g / mol, c. a compound comprising at least one group capable of reacting with an isocyanate group and at least one hydrophilic group which preferably comprises a salt or which may comprise a salt after reaction with a neutralizing agent, and d. an ethylenically unsaturated compound comprising at least one group capable of reacting with an isocyanate group and at least one ethylenically unsaturated group, a plurality of polyurethane particles which are non-radiation curable and have a median particle size D50 of 1 to 10 μm, and water.

[0011] In a second aspect, the present invention relates to a coating formed by curing a composition according to an embodiment of the first aspect.

[0012] In a third aspect, the present invention relates to a method of forming a coating according to an embodiment of the second aspect, comprising the steps of applying a composition according to an embodiment of the first aspect to a surface and curing the composition, thereby forming the coating.

[0013] In a fourth aspect, the present invention relates to the use of a coating according to an embodiment of the second aspect for consumer electronics, home appliances, automotive interiors and exteriors, packaging, furniture, in-mold decoration, industrial applications, graphical applications or in-mold labelling.

[0014] In a fifth aspect, the present invention relates to a method of forming an aqueous radiation curable composition according to any embodiment of the first aspect of the present invention, comprising the step of mixing a compound of a radiation curable polyurethane dispersion obtained by reacting a. a compound comprising at least two isocyanate groups, b. a polyol having a molecular weight of at least 500 g / mol, c. a compound comprising at least one group capable of reacting with an isocyanate group and preferably at least one hydrophilic group comprising a salt or capable of comprising a salt after reaction with a neutralizing agent, and d. an ethylenically unsaturated compound comprising at least one group capable of reacting with an isocyanate group and at least one ethylenically unsaturated group, with a plurality of polyurethane particles that are non-radiation curable and have a median size D50 of 1-10 μm, and water.

[0015] In the context of the present invention, an ethylenically unsaturated compound is a compound having at least one ethylenically unsaturated functional group. The ethylenically unsaturated functional group is typically suitable for undergoing radical polymerization, i.e. free radical polymerization. In the context of the present invention, an "ethylenically unsaturated functional group" can refer to a group having at least one carbon-carbon double bond, i.e. a π bond, that can undergo radical polymerization under the influence of irradiation and / or an activated (photo)initiator. The polymerizable ethylenically unsaturated functional group is generally selected from an allyl group, a vinyl group and a (meth)acryloyl group. The double bond can alternatively or additionally be derived, for example, from an unsaturated acid, an unsaturated fatty acid or an acrylamide. In a preferred embodiment, the ethylenically unsaturated compound is a (meth)acrylated compound. In the present specification, a (meth)acrylated compound is a compound that contains one or more (meth)acryloyl groups.

[0016] In the context of the present invention, the term (meth)acrylic compound is understood to include both acrylated and methacrylated compounds or derivatives thereof, as well as mixtures thereof. In the context of the present invention, the term (meth)acrylate is meant to include both acrylate and methacrylated compounds. In a preferred embodiment, the (meth)acrylated compound is an acrylated compound. Such compounds contain at least one acrylate (CH 2 =CHCOO-) and / or methacrylate (CH 2 =CCH 3 COO-) groups. Compounds containing only one (meth)acrylate functional group are preferred.

[0017] In the context of the present invention, the term "(meth)acrylic" encompasses the presence of acrylic and / or methacrylic groups separately or as a mixture of acrylic and methacrylic groups on the compound.

[0018] In the context of the present invention, a "water-dispersible compound" or "water dispersion" or "dispersion", i.e., a dispersion of a self-water-dispersible compound, is a compound that, when mixed with water, forms a stable two-phase system of small particles dispersed in water without the aid of additional emulsifiers or dispersants. A "water-dispersible compound" is a compound that is insoluble in water, but can be dispersed in water without the need for a separate aid, such as the use of an emulsifier or dispersant, and forms a water-dispersible compound (i.e., a water dispersion). That is, when dispersed, it forms a stable two-phase system of small discrete particles or droplets dispersed in water. For example, in a "polyurethane dispersion", the discrete particles are polyurethane polymers. The particles are the dispersed or internal phase, and the aqueous medium is the continuous or external phase. In this specification, "stable" is meant to refer to the substantial absence of coalescence (droplets) or aggregation (particles) resulting in phase separation, creaming, or sedimentation of a heterogeneous system after 1 day at 60°C, preferably after 2 days or more, typically after 4 days or more, and most preferably after 10 days at 60°C.

[0019] In the context of the present invention, the term "polyol" denotes a compound containing two or more hydroxyl groups per molecule.

[0020] In the context of the present invention, the term "polyamine" denotes a compound containing two or more primary or secondary amine groups per molecule.

[0021] In a first aspect, the present invention relates to an aqueous radiation curable composition comprising a radiation curable polyurethane dispersion obtainable by reacting a. a compound comprising at least two isocyanate groups, b. a polyol having a molecular weight of at least 500 g / mol, c. a compound comprising at least one group capable of reacting with an isocyanate group and at least one hydrophilic group which preferably comprises a salt or which may comprise a salt after reaction with a neutralizing agent, and d. an ethylenically unsaturated compound comprising at least one group capable of reacting with an isocyanate group and at least one ethylenically unsaturated group, a plurality of polyurethane particles which are non-radiation curable and have a median particle size D50 of 1-10 μm, and water.

[0022] In an embodiment of the first aspect, the radiation curable polyurethane dispersion is obtained by reacting 10-60 parts by weight of compound a., 1-40 parts by weight of compound b., 2-25 parts by weight of compound c. and 15-85 parts by weight of compound d., the parts by weight of compounds a., b., c. and d. adding up to 100. Preferably at least 15, such as at least 20 parts by weight of compound a. are present in the reaction. Preferably up to 50 parts by weight of compound a., more typically up to 40 parts by weight of compound a. are present in the reaction. Preferably 10-50, such as 20-40 parts by weight of compound a. are present in the reaction. In an embodiment, at least 80% by weight, preferably at least 85% by weight, more preferably at least 90% by weight of the compounds reacted to form the radiation curable polyurethane dispersion consist of compounds a., b., c. and d. In an embodiment, at least 80% by weight, preferably at least 85% by weight, more preferably at least 90% by weight of the compounds reacted to form the radiation curable polyurethane dispersion consist of compounds a., b., c., d., e., if present, and f., if present.

[0023] In an embodiment of the present invention, compound a. comprises an organic compound containing at least two, for example 2 to 6, isocyanate groups. That is, compound a. is a polyisocyanate compound. In an embodiment, compound a. comprises only 2 or 3 isocyanate groups, preferably only 2 isocyanate groups. In an embodiment, compound a. is selected from aliphatic, cycloaliphatic, aromatic and / or heterocyclic polyisocyanates or a combination thereof. In an embodiment, compound a. contains allophanate groups, biuret groups and / or isocyanurate groups.

[0024] In embodiments, the aliphatic or cycloaliphatic polyisocyanate is at least one of 1,5-diisocyanatopentane, 1,6-diisocyanatohexane (HDI), 1,1'-methylenebis[4-isocyanatocyclohexane] (H12MDI), 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane (isophorone diisocyanate, IPDI) or pentamethylene diisocyanate (PDI). Aliphatic polyisocyanates containing more than two isocyanate groups are derivatives of the above diisocyanates, such as 1,6-diisocyanatohexane biurets and isocyanurates. Examples of aromatic polyisocyanates are 1,4-diisocyanatobenzene (BDI), 2,4-diisocyanatotoluene (2,4-TDI), 2,6-diisocyanatotoluene (2,6-TDI), 1,1'-methylenebis[4-isocyanatobenzene] (MDI), xylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXDI), 1,5-naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI) and p-phenylene diisocyanate (PPDI).

[0025] Preferably, compound a. comprises an aliphatic or cycloaliphatic polyisocyanate. In a preferred embodiment, compound a. comprises an aliphatic or cycloaliphatic diisocyanate, such as a cycloaliphatic diisocyanate. 1,1'-methylenebis[4-isocyanatocyclohexane] (H12MDI) and / or isophorone diisocyanate (IPDI) are particularly preferred.

[0026] In embodiments, compound a. comprises a mixture of compounds described for compound a.

[0027] Preferably, the amount of polyol compound b. used to prepare the radiation curable polyurethane dispersion is present in an amount of 1 to 40 parts by weight.

[0028] In an embodiment, the polyol compound b. can be selected from polyols having a number average molecular weight of at least 500 g / mol. In an embodiment, the compound b. has a number average molecular weight of at most 5,000 g / mol, preferably at most 2,000 g / mol, more preferably at most 1,000 g / mol, calculated based on the hydroxyl index of the polyol. In this specification, the hydroxyl index can be calculated using the formula 56×2×1000 / (hydroxyl number of polyol). In an embodiment, the polyol compound b. comprises at least one of polyester polyols, polyether polyols, polycarbonate polyols, fatty dimer diols, and polyacrylate polyols, and combinations thereof.

[0029] In embodiments, the polyether polyol comprises at least one of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, or block copolymers thereof.

[0030] In an embodiment, the fatty dimer diol is obtained from the hydrogenation of a dimer acid, preferably a dimer acid containing 36 carbon atoms.

[0031] In embodiments, the polyacrylate polyol can be formed by radical polymerization of (meth)acrylic and / or (meth)acrylamide monomers, preferably initiated by a thermal radical initiator. Formation is preferably carried out in the presence of a hydroxylated mercaptan. Formation can be followed by end-group transesterification with a diol, such as 1,4-butanediol.

[0032] In a preferred embodiment of the first aspect, the polyol compound b. is a polyester or a polycarbonate.

[0033] Preferably, the polyol compound b. is a polyester polyol. In an embodiment, the polyester polyol is a hydroxyl-terminated reaction product of a polyhydric alcohol, preferably a dihydric alcohol, with a polycarboxylic acid, preferably a dicarboxylic acid or its corresponding anhydride. In an embodiment, the polyester polyol is obtained from the ring-opening polymerization of a lactone. Preferably, the polycarboxylic acids used to form the polyester polyol are aliphatic, cycloaliphatic, aromatic and / or heterocyclic, which may be substituted, saturated or unsaturated. Examples of dicarboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecane dicarboxylic acid, hexahydrophthalic acid, isophthalic acid, terephthalic acid, orthophthalic acid, tetrachlorophthalic acid, 1,5-naphthalenedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid, tetrahydrophthalic acid, trimellitic acid, trimesic acid and pyromellitic acid or mixtures thereof. The polyester polyols may further contain air-drying components such as long chain unsaturated fatty acids, especially fatty acid dimers.

[0034] Preferably, the polyhydric alcohol used in preparing the polyester polyol is selected from one or more of the diols described in the embodiments of diol compound e.

[0035] In a preferred embodiment, the polyester polyol is made primarily from the polycondensation of (1) neopentyl glycol and (2) adipic acid and / or isophthalic acid.

[0036] In embodiments in which compound b. is a polycarbonate polyol, compound b. may be a reaction product of a diol, such as ethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol or tetraethylene glycol, with at least one of the following compounds: phosgene, a dialkyl carbonate, such as dimethyl carbonate, a diaryl carbonate, such as diphenyl carbonate, or a cyclic carbonate, such as ethylene or propylene carbonate.

[0037] In embodiments, compound b. may include a mixture of compounds described with respect to compound b.

[0038] Compound c. is typically a compound, such as a saturated organic compound, that comprises at least one hydrophilic group capable of rendering the radiation-curable polyurethane dispersible in an aqueous medium. In an embodiment, the radiation-curable polyurethane may be directly dispersible, for example if the hydrophilic group is not ionic or is a salt. In an alternative embodiment, the radiation-curable polyurethane is dispersible after reacting with a neutralizing agent to provide a salt. In an embodiment, the hydrophilic group capable of rendering the polyurethane dispersible in an aqueous medium may be ionic or non-ionic. Preferably, the hydrophilic group is an ionic group, more preferably an anionic group, most preferably an acidic group or the corresponding salt. In an embodiment, the acidic group is a carboxylic acid, sulfonic acid or phosphonic acid group. In an embodiment, the salt comprises a counterion and a carboxylate, sulfonate or phosphonate. Examples of suitable counterions for the salt are ammonium, trimethylammonium, triethylammonium, sodium, potassium, lithium, etc. The non-ionic group may comprise a hydrophilic portion comprising polyethylene oxide, polypropylene oxide, or a block copolymer made therefrom. Preferably, the hydrophilic group comprises a carboxylic acid group and / or a salt thereof. Compound c. is typically a hydrophilic compound.

[0039] In an embodiment, the at least one group capable of reacting with an isocyanate group can be selected from the list consisting of a hydroxyl group, a primary amino group and a secondary amino group. In an embodiment, compound c. is a hydroxylated and / or aminated compound. In an embodiment, compound c. contains at least one, preferably at least two hydroxyl groups, or at least one, preferably at least two primary or secondary amino groups.

[0040] In a preferred embodiment, compound c. comprises a saturated hydroxycarboxylic acid containing at least one hydroxyl group and at least one carboxylic acid group. In an embodiment, the number of hydroxyl groups in compound c. is two or three. In an embodiment, the number of carboxylic acid groups in compound c. is up to three. Preferably, the hydroxycarboxylic acid is a saturated aliphatic hydroxycarboxylic acid having at least one hydroxyl group. Preferably, compound c. comprises an aliphatic saturated mono-, di- and / or tricarboxylic acid or a mixture thereof having at least one hydroxyl group per molecule.

[0041] In a preferred embodiment, compound c. comprises an aliphatic saturated monocarboxylic acid containing at least one, for example at least two, hydroxyl groups. In an embodiment, the saturated aliphatic hydroxycarboxylic acid has the general formula (HO): x R(COOH) y where R represents a linear or branched hydrocarbon moiety having 1 to 12 carbon atoms. x is an integer from 1 to 3. y is an integer from 1 to 3. In an embodiment, the sum of x+y is up to 5. In an embodiment, the hydroxycarboxylic acid comprises at least one of citric acid, maleic acid, lactic acid, or tartaric acid. Preferably, y=1 in the above general formula. In a preferred embodiment, the hydroxycarboxylic acid comprises an α,α-dimethylolalkanoic acid, such as 2,2-dimethylolpropionic acid and / or 2,2-dimethylolbutanoic acid, where x=2 and y=1 in the above general formula.

[0042] Compound c. may comprise at least one of the compounds c. discussed above. Compound c. may comprise a mixture of at least two of the compounds c. discussed above.

[0043] In an embodiment, the aqueous radiation curable composition of the present invention is an aqueous dispersion. In an embodiment, compound c. is used in an amount sufficient to render the radiation curable polyurethane water dispersible. In an embodiment, the amount of compound c. used in the synthesis of the radiation curable polyurethane dispersion ranges from 2 to 25 parts by weight, and the parts by weight of compounds a., b., c. and d. sum to 100. In an embodiment in which the hydrophilic group is an ionic group, the amount of compound c. is preferably in the range of 3 to 10 parts by weight, more preferably 3.5 to 8 parts by weight. In an embodiment in which the hydrophilic group is a non-ionic group, the amount of compound c. is preferably in the range of 5 to 25 parts by weight, more preferably 10 to 20 parts by weight.

[0044] In embodiments, the ethylenically unsaturated compound d. comprises at least one (meth)acrylic group. For example, the ethylenic unsaturation of the (meth)acrylic group can be introduced into compound d. via a terminal and / or skeletal side group, i.e., a pendant group, of compound d.

[0045] In an embodiment, compound d. is selected from compounds containing at least one acrylic and / or methacrylic group. In an embodiment, compound d. contains two or more nucleophilic groups (typically hydroxyl groups) capable of reacting with isocyanates. Examples of such compounds d. are polyester (meth)acrylates containing hydroxyl groups, polyether (meth)acrylates containing hydroxyl groups, polyester ester (meth)acrylates containing hydroxyl groups, and / or polyepoxy (meth)acrylates containing hydroxyl groups. In an embodiment, compound d. is an acrylate. In an embodiment, compound d. comprises at least one linear compound containing an average of two hydroxyl groups per molecule. Such compounds are well known in the art. Preferably, compound d. comprises polyester (meth)acrylates and / or polyepoxy (meth)acrylates having two or more, typically an average of two, hydroxyl groups. Preferably, compound d. comprises an aliphatic compound.

[0046] Preferably, compound d. comprises one or more ethylenically unsaturated functional groups (e.g., acrylic and / or methacrylic groups) and one nucleophilic functional group (typically a hydroxyl group) capable of reacting with an isocyanate. More preferably, compound d. comprises a (meth)acryloyl monohydroxy compound, e.g., a poly(meth)acryloyl monohydroxy compound. Preferably, compound d. comprises an acrylate. In an embodiment, compound d. comprises a mixture of at least two of the above compounds.

[0047] In an alternative embodiment, compound d. comprises the esterification product of an aliphatic and / or aromatic polyol, preferably an aliphatic polyol, having a residual average hydroxyl functionality of 0.9 to 1.1, preferably 0.95 to 1.05, with (meth)acrylic acid. In a preferred embodiment, compound d. comprises the partial esterification product of (meth)acrylic acid with a tri-, tetra-, penta- or hexahydric polyol or mixtures thereof. In an embodiment, compound d. comprises the reaction product of a polyol with ethylene oxide and / or propylene oxide or mixtures thereof. In an embodiment, compound d. comprises the reaction product of a polyol with a lactone capable of reacting with said polyol in a ring-opening reaction. In an embodiment, the lactone comprises at least one of γ-butyrolactone, δ-valerolactone and ε-caprolactone, preferably δ-valerolactone and ε-caprolactone. Preferably, the alkoxylated polyol has up to 3 alkoxy groups per hydroxyl functionality and comprises ε-caprolactone. Preferably, the polyol is partially esterified with acrylic acid, methacrylic acid, or mixtures thereof until the desired residual hydroxyl functionality is reached.

[0048] Preferably, compound d. contains at least two (meth)acrylic functional groups, such as glycerol diacrylate, trimethylolpropane diacrylate, glycerol diacrylate, pentaerythritol triacrylate, ditrimethylolpropane triacrylate, dipentaerythritol pentaacrylate, and their (poly)ethoxylated and / or (poly)propoxylated equivalents (any of these).

[0049] In an embodiment, compound d. is obtained from the reaction of (meth)acrylic acid with an aliphatic, cycloaliphatic or aromatic compound and has an epoxy functional group and at least one (meth)acrylic functional group. In an embodiment, compound d. is obtained from the reaction of an aliphatic, cycloaliphatic or aromatic acid with an epoxy group containing (meth)acrylate, for example glycidyl (meth)acrylate.

[0050] Other suitable compounds that can be used for compound d. are (meth)acrylic acid esters of linear and branched polyols in which at least one hydroxy functional group is still free to react with an isocyanate group, such as hydroxyalkyl (meth)acrylates containing an alkyl group of 1 to 20 carbon atoms. For example, compound d. may include at least one of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate.

[0051] In embodiments, compound d. may include at least one of the compounds described with respect to compound d., such as a mixture thereof.

[0052] In an embodiment, the adduct contains functional groups of both compounds a. and d., i.e., both compounds a. and d. The adduct can be formed by reaction of an excess of one or more compounds a. with one or more compounds d. In another embodiment of the invention, compounds a. and d. are provided as separate molecules.

[0053] In an embodiment, the amount of compound d. used in the synthesis of the radiation curable polyurethane ranges from 15 to 85 parts by weight, preferably 15 to 70 parts by weight, more preferably 22 to 70 parts by weight, and most preferably 30 to 60 parts by weight, and the parts by weight of compounds a., b., c., and d. add up to 100. When compounds a and d are included in the adduct, the amount of the adduct used in the synthesis of the radiation curable polyurethane can be in a range having as a lower limit the sum of the lower limits of a and d, and as an upper limit the sum of the upper limits of a and d.

[0054] In an embodiment of the first aspect, the compounds reacted to obtain the compound of the radiation-curable polyurethane dispersion additionally comprise compound e., which is a diol having a molecular weight of up to 400 g / mol. In an embodiment, the parts by weight of compounds a., b., c. and d. add up to 100 and compound e. is added in an amount of 0 to 5 parts by weight, for example 1 to 5 parts by weight.

[0055] In an embodiment, compound e. comprises at least one of the following compounds: ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, dibutylene glycol, 2-methyl-1,3-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, an ethylene oxide or propylene oxide adduct of bisphenol A or hydrogenated bisphenol A, or a mixture thereof. In an embodiment, compound e. comprises at least one of the following compounds: glycerol, trimethylolethane, trimethylolpropane, ditrimethylolethane, ditrimethylolpropane, and pentaerythritol and / or dipentaerythritol.

[0056] In an embodiment of the first aspect, the compounds reacted to obtain the radiation-curable polyurethane dispersion additionally comprise a compound f. comprising at least two amino groups independently selected from primary and secondary amino groups. In an embodiment, the compound f. has a molecular weight of up to 200 g / mol. The compound f. can function as a chain extender.

[0057] The chain-extended polyamines typically have an average functionality of 2 to 4, more preferably 2 to 3. Compound f. is preferably a water-soluble aliphatic, cycloaliphatic, aromatic or heterocyclic primary and / or secondary polyamine or hydrazine having up to 60, preferably up to 12 carbon atoms.

[0058] The amount of compound f. added to the reaction to form the radiation-curable polyurethane can be determined from the amount of residual, i.e. unreacted, isocyanate groups present in the radiation-curable polyurethane prepolymer. In this specification, the radiation-curable polyurethane prepolymer is the compound obtained by the reaction of compounds a., b., c. and d., optionally e., and before the reaction with compound f. In an embodiment, compound f. is added after the reaction of compounds a., b., c. and d., optionally e. In an embodiment, the ratio of the functionality of amine groups in compound f. to isocyanate groups in the prepolymer obtained after the reaction of compounds a., b., c. and d., optionally e., ranges from 0.25 to 1.2, preferably 0.5 to 0.95. The residual isocyanate content is typically measured by isocyanate titration with an amine. The amount of amine groups is typically obtained by calculation. In embodiments in which compound f. is reacted to obtain a radiation-curable polyurethane, compound f. can be added in an amount ranging from 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and the sum of the parts by weight of all compounds reacted to obtain a radiation-curable polyurethane is 100. In embodiments, the parts by weight of compounds a., b., c., and d. add up to 100, and compound f. is added in an amount of 1 to 15 parts by weight, preferably 1 to 10 parts by weight, and more preferably 1 to 5 parts by weight.

[0059] In an embodiment, the chain extending amine, i.e. compound f., comprises at least one of the following compounds: hydrazine, ethylenediamine, piperazine, 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 2-methylpentamethylenediamine, triethylenetriamine, isophoronediamine (or 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane), aminoethylethanolamine, polyethyleneamines, polyoxyethyleneamines and polyoxypropyleneamines (e.g. Jeffamine from Huntsman) and mixtures thereof.

[0060] In an embodiment, the composition comprises an additional ethylenically unsaturated compound. The additional ethylenically unsaturated compound can be added to the composition before, during or after dispersing the water-dispersible radiation-curable polyurethane. Typically, the additional ethylenically unsaturated compound does not react to become part of the radiation-curable polyurethane dispersion. For example, the additional ethylenically unsaturated compound is added to the composition only after the formation of the radiation-curable polyurethane dispersion. In an embodiment comprising a water-dispersible non-radiation-curable additional polyurethane, the additional ethylenically unsaturated compound does not react to become part of the water-dispersible radiation-curable additional polyurethane. In other words, typically, the unreacted additional ethylenically unsaturated compound is part of the composition. In an embodiment, the additional ethylenically unsaturated compound does not contain a functional group capable of reacting with an isocyanate group. In these embodiments, the additional ethylenically unsaturated compound can be added before or during the step of reacting compounds a., b., c. and d. If the additional ethylenically unsaturated compound is added before dispersing the radiation-curable polyurethane dispersion in water, good dispersion stability is generally obtained. In an embodiment, the additional ethylenically unsaturated compound is different from compound d. In an embodiment, the further ethylenically unsaturated compound is also a (meth)acrylated compound.

[0061] In embodiments, the further ethylenically unsaturated compound is independently selected from the (meth)acrylated compounds described above for compound d. In embodiments, the further ethylenically unsaturated compound can be any compound that is ethylenically unsaturated and does not contain a functional group capable of reacting with an isocyanate group.

[0062] In an embodiment, the further ethylenically unsaturated compound comprises aliphatic and aromatic polyhydric polyols, which are preferably esterified with (meth)acrylic acid. Thereby, preferably, the further ethylenically unsaturated compound does not contain residual hydroxyl functionality. Preferably, the further ethylenically unsaturated compound is an esterification product of (meth)acrylic acid with a tri-, tetra-, penta- and / or hexahydric polyol or a mixture thereof. In an embodiment, the further ethylenically unsaturated compound is a reaction product of a tri-, tetra-, penta- and / or hexahydric polyol with ethylene oxide and / or propylene oxide or a mixture thereof. In an embodiment, the further ethylenically unsaturated compound is a reaction product of a tri-, tetra-, penta- and / or hexahydric polyol with a lactone. The ethylene oxide, propylene oxide and lactone can react with the polyol in a ring-opening reaction. In an embodiment, the lactone is γ-butyrolactone, δ-valerolactone or ε-caprolactone, preferably δ-valerolactone or ε-caprolactone. In a preferred embodiment, the polyol is an alkoxylated polyol having up to two alkoxy groups per hydroxyl functionality or a polyol modified with ε-caprolactone. Preferably, the modified or unmodified polyol is esterified with acrylic acid, methacrylic acid or a mixture thereof, preferably until no residual hydroxyl functionality remains. In an embodiment, the further ethylenically unsaturated compound comprises one or a mixture of trimethylolpropane triacrylate, glycerol triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate and their (poly)ethoxylated and (poly)propoxylated equivalents.

[0063] In an embodiment, the further ethylenically unsaturated compound comprises one of the following compounds: urethane (meth)acrylates, epoxy (meth)acrylates, polyester (meth)acrylates or (meth)acrylic (meth)acrylates or mixtures thereof. In a preferred embodiment, the further ethylenically unsaturated compound is a polyurethane (meth)acrylate dispersion.

[0064] In an embodiment, the further ethylenically unsaturated compound is an aqueous compound. The further ethylenically unsaturated compound can be water-dispersible or water-dilutable. Examples of urethane (meth)acrylate dispersions are UCECOAT® 7788, UCECOAT® 7655, UCECOAT® 7700, UCECOAT® 7230, UCECOAT® 7240 and UCECOAT® 7177. Examples of suitable water-dilutable urethane (meth)acrylates are, for example, UCECOAT® 6569, EBECRYL® 2002 and EBECRYL® 11. Such (meth)acrylate compounds are well known in the art. Methods for producing such (meth)acrylate compounds are also well known in the art and have already been described in various patent applications. In an embodiment, the radiation curable polyurethane dispersion, and, if present, the non-radiation curable further polyurethane dispersion, are present in an amount of 100 parts by weight and the further ethylenically unsaturated compound is present in an amount of 0 to 20 parts by weight, for example 1 to 20 parts by weight.

[0065] In embodiments, the further ethylenically unsaturated compound may comprise at least one of the compounds described with respect to the further ethylenically unsaturated compound, such as a mixture thereof.

[0066] In an embodiment of the first aspect, the polyurethane particles are not radiation curable. The polyurethane particles have a median diameter D50 of 5-8 μm. As used herein, D50 is the diameter in microns that separates the diameter distribution with half of the particles above and half below a micron diameter. The polyurethane particles of the present invention can alternatively be described as polyurethane beads, polyurethane fillers, or polyurethane microparticles or microspheres. It is an advantage of an embodiment of the present invention that the polyurethane particles can impart a soft feel to a coating formed from the composition.

[0067] In an embodiment of the first aspect, the T of the polyurethane particles g , i.e. the glass transition temperature is at most 0°C, preferably at most -40°C, more preferably at most -50°C. It is an advantage of an embodiment of the present invention that polyurethane particles can be glassy at room temperature, thus imparting a soft feel to coatings comprising the polyurethane particles. In an embodiment, the polyurethane particles are preferably at least insoluble in water. The polyurethane particles are chemically crosslinked polyurethane-based molecules. This distinguishes the particles from aggregates or micelles formed by physical interactions of the molecules, e.g. hydrophobic / hydrophilic interactions. In an embodiment, the polyurethane particles have an oil absorption of at most 120%, i.e. 120 grams of oil per 100 grams of polyurethane particles. In this specification, the oil absorption is preferably determined using ISO or ASTM techniques, e.g. using ASTM D281.

[0068] In an embodiment, the polyurethane particles have a second volume that is at least 90% of the first volume, as determined using a microcompression testing device-testing machine-Shimadzu MCT series, before compression and the first volume after, for example, 1 minute of compression and subsequent relaxation, using a force of 63 mN. It is an advantage of an embodiment of the present invention that the polyurethane particles are soft and elastic. The soft feel and elasticity can impart a soft feel to a coating that includes the polyurethane particles. The polyurethane particles are solid, i.e., not liquid or gaseous.

[0069] The polyurethane particles are typically transparent, although the invention is not so limited. In certain embodiments, the polyurethane particles may include a dye or pigment.

[0070] In an embodiment, the polyurethane particles consist of at least 60%, preferably at least 80%, more preferably at least 90%, most preferably at least 95% polyurethane. Typically, the polyurethane particles consist essentially of polyurethane. In an embodiment, the polyurethane of the polyurethane particles is an aliphatic polyurethane. In an embodiment, the polyurethane particles are formed of a polyol, preferably comprising at least one of a polyester polyol, a polycarbonate polyol, or a polyether polyol. In a preferred embodiment, the polyurethane particles can be obtained from renewable plant sources. In a preferred embodiment, the polyurethane particles are obtained using a water-based process. In a preferred embodiment, the polyurethane particles are obtained using a process that does not include a solvent different from water, preferably does not include an organic solvent. It is an advantage of an embodiment of the present invention that the polyurethane particles can be free of volatile organic compounds (VOCs), alkylphenol ethoxylates (APEOs), phthalates, formaldehyde, and heavy metals. In an embodiment, the polyurethane particles do not include isocyanate groups. Suitable polyurethane particles for use in embodiments of the present invention are, for example, Decosphaera Transparent® HT8-20, MicroTouch® 850XF and Addimat® 8FT.

[0071] In an embodiment of the first aspect, the composition comprises a non-radiation curable further polyurethane dispersion obtained by reacting i. a compound comprising at least two isocyanate groups, ii. a polyol having a molecular weight of at least 500 g / mol, iii. a compound comprising at least one group capable of reacting with an isocyanate group and preferably at least one hydrophilic group comprising a salt or capable of comprising a salt after reaction with a neutralizing agent, and iv. a compound comprising at least two amino groups selected from primary and secondary amino groups. In an embodiment, the compound iv. has a molecular weight of up to 200 g / mol, for example up to 150 g / mol.

[0072] In an embodiment, the non-radiation curable further polyurethane dispersion is prepared by reacting compounds i. and ii., and preferably iii., thereby forming a prepolymer, dispersing the prepolymer in an aqueous solvent, and chain extending the prepolymer by reacting it with compound iv.

[0073] In embodiments, compound i. can be independently selected from any of the compounds described for compound a.

[0074] Any polyol known to one of ordinary skill in the art can be used as polyol ii. In embodiments, compound ii. can be independently selected from any of the compounds described for compound b. Exemplary polyols include, but are not limited to, glycol and polymer polyols. In an embodiment, the glycol includes alkylene glycols such as ethylene glycol; 1,2- and 1,3-propylene glycol; 1,2-, 1,3-, 1,4- and 2,3-butylene glycol; hexanediol; neopentyl glycol; 1,6-hexanediol; 1,8-octanediol; and other glycols such as bisphenol-A, cyclohexanediol, cyclohexanedimethanol (1,4-bishydroxymethylcyclohexane), 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, caprolactone diol, dimerate diol, hydroxylated bisphenol, polyether glycol, halogenated diol, and mixtures thereof. However, the present invention is not limited thereto.

[0075] In embodiments, the polymer polyol used in compound ii. can be selected from polyester polyols, polyether polyols, polyhydroxy polyester amides, hydroxyl-containing polycaprolactones, hydroxyl-containing acrylic interpolymers, hydroxyl-containing epoxides, polyalkylene ether polyols, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polythioethers, polysiloxane polyols, ethoxylated polysiloxane polyols, polybutadiene polyols, and mixtures thereof. Representative polyols useful in the process of the present invention include those described in U.S. Patent Nos. 4,108,814 and 6,576,702, the contents of which are incorporated herein by reference.

[0076] In a preferred embodiment, polyol ii. comprises a polymer polyol. Preferred polymer polyols include polyester polyols, polyether polyols, and hydroxy polycarbonates.

[0077] Polyester polyols are esterification products prepared by reacting an organic polycarboxylic acid or anhydride with a stoichiometric excess of a diol. In embodiments, the polyester polyol used in polyol ii. may include at least one of polyglycol adipates, isophthalates, orthophthalates, terephthalates, polycaprolactone polyols, sulfonated polyols, and mixtures thereof. In embodiments, polyester polyols can be formed from diols described for polyol b. Preferred diols for forming polyester polyols are ethylene glycol, butylene glycol, hexanediol, and neopentyl glycol. Suitable carboxylic acids for making polyester polyols include, but are not limited to, dicarboxylic and tricarboxylic acids and anhydrides such as maleic acid, maleic anhydride, succinic acid, glutaric acid, glutaric anhydride, adipic acid, suberic acid, pimelic acid, azelaic acid, sebacic acid, chlorendic acid, 1,2,4-butanetricarboxylic acid, phthalic acid, isomers of phthalic acid, phthalic anhydride, fumaric acid, dimer fatty acid, and mixtures thereof. Preferred polycarboxylic acids for forming polyester polyols include aliphatic or aromatic dibasic acids.

[0078] The hydroxypolyether can be selected from any hydroxypolyether known in the art. In embodiments, the hydroxypolyether is obtained by polymerization of an epoxide, such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, or epichlorohydrin, or mixtures thereof. The epoxide is catalyzed by polymerization of a catalyst, such as BF 3The polymerization can be carried out in the presence of, or in the absence of, a catalyst. Hydroxy polyethers can be formed by the addition of epoxides, optionally as a mixture of epoxides, to a component containing reactive hydrogen atoms, such as an alcohol or an amine (e.g., water, ethylene glycol, 1,3- or 1,2-propylene glycol, 4,4'-dihydroxydiphenylpropane or aniline).

[0079] In embodiments, the hydroxy polythioethers are formed by condensing thiodiglycol by self-condensation and / or by condensation with another glycol, dicarboxylic acid, formaldehyde, aminocarboxylic acid, or amino alcohol. The hydroxy polythioethers may thereby include polythio mixed ethers, polythioether esters, or polythioether ester amides. However, the hydroxy polythioethers are not limited to these embodiments.

[0080] In embodiments, the hydroxy polyacetal includes glycols such as diethylene glycol, triethylene glycol, 4,4'-dioxyethoxydiphenyldimethylmethane, and the reaction product of hexanediol with formaldehyde. In embodiments, the hydroxy polyacetal is obtained by polymerization of cyclic acetals. However, the hydroxy polyacetal is not limited to these embodiments.

[0081] The hydroxy polycarbonate can be any hydroxy polycarbonate known to one of ordinary skill in the art. In embodiments, the hydroxy polycarbonate is formed by reacting a diol, such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, or tetraethylene glycol, with a diaryl carbonate, such as diphenyl carbonate or phosgene.

[0082] In embodiments, the hydroxypolyesteramides and hydroxypolyamides include predominantly linear, e.g., linear, condensates obtained from the reaction of saturated or unsaturated polycarboxylic acids or anhydrides thereof and polyhydric saturated or unsaturated amino alcohols, diamines, polyamines, or mixtures thereof.Preferred amino alcohols, diamines and polyamines used to form the polyesteramides and polyamides include 1,2-diaminoethane, 1,6-diaminohexane, 2-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 1,12-diaminododecane, 2-aminoethanol, 2-[(2-aminoethyl)amino]ethanol, piperazine, 2,5-dimethylpiperazine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, (isophoronediamine or IPDA), bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, 1,4-diaminocyclohexane, 1,2-propylenediamine, hydrazine, urea, amino acid hydrazides, hydrazides of semicarbazide carboxylic acids, bishydrazides and bissemicarbazides, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N,N,N-tris(2-aminoethyl)amine N-(2-piperazinoethyl)ethylenediamine, N,N'-bis(2-aminoethyl)piperazine, N,N,N'-tris(2-aminoethyl)ethylenediamine, N-[N-(2-aminoethyl)-2-aminoethyl]-N'-(2-aminoethyl)piperazine, N-(2-aminoethyl)-N'-(2-piperazinoethyl)ethylenediamine, N,N-bis(2-aminoethyl)-N-(2-piperazinoethyl)amine, N,N-bis(2-piperazinoethyl)amine, polyethyleneimine Examples of suitable amines include, but are not limited to, iminobispropylamine, guanidine, melamine, N-(2-aminoethyl)-1,3-propanediamine, 3,3'-diaminobenzidine, 2,4,6-triaminopyrimidine, polyoxypropyleneamine, tetrapropylenepentamine, tripropylenetetramine, N,N-bis(6-aminohexyl)amine, N,N'-bis(3-aminopropyl)ethylenediamine, and 2,4-bis(4'-aminobenzyl)aniline, and mixtures thereof.Other suitable diamines and polyamines include Jeffamine® D-2000 and D-4000 (available from Huntsman Chemical Company), which are amine-terminated polypropylene glycols differing only in molecular weight. Polyhydroxyl compounds containing urethane and urea groups can be used. In certain embodiments, the hydroxypolyamide is a linear polyamide formed by reacting adipic acid and 1,6-diaminohexane. In certain embodiments, the polyesteramide is formed by reacting adipic acid, 1,6-hexanediol, and ethylenediamine.

[0083] However, polyol ii. is not limited to any of the embodiments described above.For example, polyol ii. can be selected from any polyol described in High Polymer, Vol. XVI, "Polyurethane, Chemistry and Technology" by Saunders-Frisch, Interscience Publisher, New York, London, Vol. I, 1962, pages 32-42 and 44-54, and Vol. II, 1964, pages 5-6 and 198-199, and Kunststoff-Handbuch, Vol. VII, Vieweg-Hochtlen, Carl-Hanser-Verlag, Munich, 1966, for example, pages 45-71.

[0084] In embodiments, polyol ii. comprises two or more of the compounds described for polyol ii., i.e. polyol compound ii. can be a mixture. In a preferred embodiment of the first aspect, polyol compound ii. is a polyester or a polyether.

[0085] In embodiments, compound iii. can be independently selected from any of the compounds described with respect to compound c.

[0086] In embodiments, compound iv. can be independently selected from any of the compounds described for compound f.

[0087] In an embodiment of the first aspect, the non-radiation curable further polyurethane dispersion represents 0.1-40 wt. % of the sum of the masses of the non-radiation curable further polyurethane dispersion, the radiation curable polyurethane dispersion and the polyurethane particles. In an embodiment, the non-radiation curable further polyurethane dispersion is provided as an aqueous dispersion. Preferably, the aqueous dispersion comprises 30-45 wt. % of the water-dispersible non-radiation curable further polyurethane. Preferably, the aqueous dispersion has a kinematic viscosity of less than 1000 mPa·s, preferably less than 500 mPa·s, more preferably less than 200 mPa·s. Preferably, the pH of the aqueous dispersion is 7-10. Preferably, the non-radiation curable further polyurethane dispersion has a Tg of 0-100° C., for example 10-60° C. Preferably, the Mw of the water-dispersible non-radiation curable further polyurethane is at least 100,000 g / mol, for example at least 1,000,000 g / mol. Examples of commercially available aqueous dispersions which may contain suitable non-radiation curable further polyurethane dispersions are Daotan® 6490, Daotan® 6491 and Daotan® 6493.

[0088] In an embodiment of the first aspect, the compounds reacted to obtain the non-radiation curable further polyurethane dispersion additionally comprise compound v., which is a diol having a molecular weight of less than 500 g / mol, preferably at most 150 g / mol. Diol v. can be independently selected from any of the compounds described for compound b., with the proviso that diol v. has a Mw of 500 g / mol or less. In an embodiment of the first aspect, the weight ratio of radiation curable polyurethane dispersion to non-radiation curable further polyurethane dispersion in the composition is at least 1.5.

[0089] In an embodiment of the first aspect, the plurality of polyurethane particles constitutes 3-20% by weight of the composition as solids. In the following embodiments, the amount of polyurethane particles as solids may be independent of the amount of water in the composition and may depend only on the concentration of polyurethane present in the composition. In an embodiment that does not include an additional non-radiation curable polyurethane dispersion, the weight ratio of the plurality of polyurethane particles to the radiation curable polyurethane dispersion may be 0.08-1.0. In an embodiment that includes a radiation curable additional polyurethane dispersion, the weight ratio of the plurality of polyurethane particles to the sum of the compounds of the radiation curable polyurethane dispersion and the radiation curable additional polyurethane dispersion may be 0.08-1.0.

[0090] In a preferred embodiment the composition comprises 7-25 wt.-% of a radiation curable polyurethane dispersion, 0-15 wt.-% of a non-radiation curable further polyurethane dispersion, 3-20 wt.-% of polyurethane particles, 0.1-5 wt.-% of a photoinitiator, 0-5 wt.-%, for example 0.1-5 wt.-% of an additive different from the photoinitiator and 30-80 wt.-% of water.

[0091] The radiation curable polyurethane dispersion and the non-radiation curable polyurethane dispersion can be provided as a dispersion in water. That is, the radiation curable polyurethane dispersion can be provided as a radiation curable polyurethane dispersion. The water-dispersible non-radiation curable polyurethane can be provided as a non-radiation curable polyurethane dispersion. Preferably, the dispersion comprises 30-50% by weight of polyurethane, the remainder being water. In these embodiments, preferably, the composition comprises 30-85% by weight of the radiation curable polyurethane dispersion, 0-40% by weight of a dispersible further polyurethane compound, 3-20% by weight of polyurethane particles, 0.1-5% by weight of a photoinitiator, 0.1-5% by weight of an additive different from the photoinitiator, and 0-20% by weight of additional water in addition to the water contained in the dispersion.

[0092] In an embodiment, the composition of the first aspect may further comprise at least one additive selected from rheology modifiers, thickeners, coalescing agents, defoamers, wetting agents, adhesion promoters, flow and leveling agents, biocides, surfactants, stabilizers, antioxidants, waxes, further fillers different from the polyurethane particles, nanoparticles different from the polyurethane particles and radiation curable polyurethanes and non-radiation curable polyurethanes, matting agents, inert or functional resins, pigments, dyes and tints. In a preferred embodiment of the first aspect, the composition further comprises at least one of the following additives: catalysts, polymerization inhibitors or photoinitiators.

[0093] In embodiments, at least one additive, such as a rheology modifier, anti-settling agent, wetting agent, leveling agent, anti-cratering agent, defoamer, slip agent, flame retardant, UV protection agent, or adhesion promoter, is suitable to improve the application of the formulated dispersion to a substrate. Examples of suitable inhibitors include, but are not limited to, hydroquinone (HQ), methylhydroquinone (THQ), tert-butylhydroquinone (TBHQ), di-tert-butylhydroquinone (DTBHQ), hydroquinone monomethyl ether (MEHQ), 2,6-di-tert-butyl-4-methylphenol (BHT), and the like. Inhibitors may include phosphines, such as triphenylphosphine (TPP) and trisnonylphenylphosphite (TNPP), phenothiazine (PTZ), triphenylantimony (TPS), and mixtures thereof.

[0094] The aqueous radiation curable composition according to the embodiment of the present invention may be curable by irradiation, for example by ultraviolet light. Preferably, the irradiation is carried out in the presence of a photoinitiator. The aqueous radiation curable composition may alternatively be cured by electron beam irradiation, which may result in good curing in the absence of a photoinitiator. The composition according to the embodiment of the present invention may be fast curable. The composition may be cured, for example, by UV LED and / or HUV.

[0095] In embodiments, the photoinitiator comprises a low to non-yellowing photoinitiator such as Omnirad® 1000, Omnirad® 481 from IGM, DOUBLECURE® 200 from Comindex, Chemcure® 73, Chemcure® 73-w, Chemcure® 481 from Chembridge, Irgacure® 184 and Darocure® 1173 from IGM. If the end use of the water-based radiation curable composition requires low migration and / or is in food packaging, it may be preferred to use polymeric photoinitiators such as Omnipol® grades from IGM, Irgacure® 2959 from IGM or anticorrosive thioxanthone photoinitiators. When different end uses of the water-based radiation curable composition are considered, such as inks, it may be preferred to use a photoinitiator together with an amine synergist, such as EBECRYL® P115, EBECRYL® P116 or DOUBLECURE® 225. When UV LED curing is used for curing the composition, it is preferred to use EBECRYL® LED01 or EBECRYL® LED02.

[0096] The radiation curable polyurethane dispersion according to an embodiment of the first aspect may comprise an amount of copolymerizable ethylenically unsaturated groups of at least 1 meq / g, typically at least 1.5 meq / g, preferably at least 2 meq / g. In this specification, meq means milliequivalent and g means grams. Typically, this amount does not exceed 10 meq / g, more preferably does not exceed 7 meq / g, most preferably does not exceed 5 meq / g. That is, the radiation curable polyurethane dispersion may have a degree of unsaturation ranging from 1 to 10 meq of double bonds per gram of radiation curable polyurethane dispersion, preferably from 1.5 to 7 meq of double bonds per gram of radiation curable polyurethane dispersion, most preferably from 2 to 5 meq of double bonds per gram of radiation curable polyurethane dispersion.

[0097] The amount of ethylenically unsaturated groups in radiation-curable polyurethane dispersions can be determined by nuclear magnetic resonance spectroscopy (NMR). The amount of ethylenically unsaturated groups can be expressed in meq per gram of solids. For the determination, a dry, i.e. water- and solvent-free, sample of radiation-curable polyurethane can be dissolved in N-methylpyrrolidone. The sample can be subjected to a NMR spectroscopy to determine the molar concentration of ethylenically unsaturated groups. 1 It is measured using H-NMR analysis, for example 1,3,5-bromobenzene can be used as an internal standard. Comparison of the peaks assigned to the protons attached to the aromatic rings of the internal standard with the peaks assigned to the protons of the ethylenically unsaturated groups in the radiation-curable polyurethane dispersion can allow the calculation of the molar concentration of the ethylenically unsaturated groups. The molar concentration of the ethylenically unsaturated groups can be assumed to be proportional to (A×B) / C. In this specification, A is the number of times that the ethylenically unsaturated groups are assigned to the protons of the ethylenically unsaturated groups in the radiation-curable polyurethane dispersion. 1 Herein, B is the moles of the internal standard in the sample. Herein, C is the moles measured relative to the internal standard. 1 is the integral of the H peak.

[0098] Alternatively, the amount of ethylenically unsaturated groups can be measured by titration after the addition of an excess of pyridinium sulfate dibromide relative to the ethylenically unsaturated groups. Here, for example, glacial acetic acid can be used as the solvent and mercuric acetate can be used as the catalyst. The excess liberates iodine in the presence of potassium iodide, which is then titrated with sodium thiosulfate.

[0099] Typically, radiation curable polyurethane dispersions according to embodiments of the present invention comprise a polymeric or oligomeric compound. In an embodiment, the radiation curable polyurethane dispersions according to the present invention have a number average molecular weight (Mw) of 500 to 20,000 Daltons, i.e. g / mol, preferably 800 to 10,000 Daltons, most preferably 1,000 to 5,000 Daltons. The weight average molecular weight (Mw) is typically measured by gel permeation chromatography. For example, gel permeation chromatography can be performed using THF as eluent, a 3×PLgel 5 μm Mixed-D LS 300×7.5 mm column, suitable for the Mw range of 162 to 377400 g / mol, and calibrated with polystyrene standards at 40° C.

[0100] In an embodiment, the aqueous radiation curable composition according to an embodiment of the present invention has a total solids content of 30 to 65 wt%, preferably 35 to 50 wt%. In this specification, the total solids content includes the radiation curable polyurethane dispersion, the polyurethane particles, the optional non-radiation curable further polyurethane dispersion and the optional solid additives. In an embodiment, the non-solid, e.g. liquid, content of the aqueous radiation curable composition comprises water, preferably consists of water. In an embodiment, the aqueous radiation curable composition has a viscosity measured at 25°C of at most 1,000 mPa·s, preferably at most 800 mPa·s, more preferably at most 500 mPa·s, even more preferably at most 200 mPa·s. In an embodiment, the aqueous radiation curable composition has a pH of 6 to 11, preferably 6 to 8.5.

[0101] Water-based radiation-curable polyurethanes typically form nanoparticles when dispersed in water. Typically, the average or median particle size of radiation-curable polyurethanes is up to 200 nm, preferably up to 150 nm. Typically, the average or median particle size of non-radiation-curable polyurethanes is up to 200 nm, preferably up to 150 nm.

[0102] In embodiments, the radiation curable polyurethane dispersion has a Tg of from 0 to 100°C, for example from 10 to 60°C.

[0103] Any feature of any embodiment of the first aspect may be described independently as correspondingly described for any embodiment of any of the other aspects of the invention.

[0104] In a second aspect, the present invention relates to a coating formed by curing a composition according to an embodiment of the first aspect. In an embodiment, the coating has a thickness perpendicular to the surface of the surface of from 2 to 200 μm. In this specification, thickness is the thickness of the dried coating typically obtained after removal of the liquid, including water.

[0105] Any feature of any embodiment of the second aspect may be described independently as correspondingly described for any embodiment of any of the other aspects of the invention.

[0106] In a third aspect, the present invention relates to a method of forming a coating according to an embodiment of the second aspect, comprising the steps of applying a composition according to an embodiment of the first aspect to a surface and curing the composition, thereby forming a coating. In an embodiment, the composition may be applied to the surface in any possible manner, for example via roller coating, spray application, inkjet or curtain coating. In an embodiment, the method comprises the further step of drying the coating to remove water, and optionally other solvents, contained in the composition. In an embodiment, the composition is applied to the surface so as to form a coating having a surface thickness of 2 to 200 μm in a direction perpendicular to the surface of the surface. In this specification, thickness is the thickness of the dried coating.

[0107] In an embodiment of the third aspect, the composition is applied to the surface at a temperature of 40-60° C. Curing of the composition can then be carried out at a temperature of 10-50° C., for example 20-40° C.

[0108] Although the specific application of radiation curable aqueous compositions to form coatings is described, the present invention is not limited thereto.In fact, radiation curable aqueous compositions according to the present invention can be used to form coatings (transparent and colored, glossy or matte), inks, paints, varnishes (such as overprint varnishes) and adhesives.Radiation curable aqueous compositions can further be used to form composites, gel coats, 3D curing and generally to create 3D objects (e.g. three-dimensional objects made from polyethylene, polypropylene, polycarbonate, polyvinyl chloride, optionally pre-coated with other coatings, e.g. polyurethane).

[0109] The present invention therefore also relates to the use of the radiation curable aqueous compositions according to embodiments of the present invention for producing inks, varnishes (such as overprint varnishes), paints, coatings and adhesives, as well as methods for producing inks, varnishes (such as overprint varnishes), coatings and adhesives, in which the compositions described herein above are used.

[0110] In an embodiment, the surface is comprised in a substrate or an article. In an embodiment, the coated substrates and articles are prepared according to an embodiment of the third aspect, where the step of applying the composition to the surface comprises coating at least a portion of the substrate or article with a radiation-curable aqueous composition, and preferably curing the radiation-curable aqueous composition. That is, the method of the third aspect comprises: (a) providing a radiation-curable aqueous composition; (b) applying the composition to a surface of an article or substrate; (c) curing the composition, preferably by irradiating the composition with radiation, e.g. actinic radiation. The method may be a method of at least partially coating an article or substrate with a coating according to an embodiment of the second aspect, comprising:

[0111] In a subsidiary aspect, the present invention relates to an article or substrate at least partially, for example completely, coated with a radiation curable aqueous composition according to the first aspect of the invention or with a coating according to an embodiment of the second aspect of the invention. The substrate can be any substrate, for example wood, metal, paper, plastic, textile, fiber, ceramic, mineral (stone, brick), cement, plaster, glass, leather or leather-like, concrete and already printed or coated materials (for example melamine panels, printed paper), etc. The article can be any article, for example a 3D article. Preferably, the article or substrate is made of wood or plastic.

[0112] The composition can be applied as a single coat (monocoat) or as a topcoat.

[0113] Radiation curable compositions are typically compositions that can be cured via a reaction involving radicals. Curing is typically performed by application of radiation, although curing can alternatively be performed, for example, by adding a peroxide to the composition. The radiation curable composition according to an embodiment of the first aspect may be curable by exposure to radiation due to the presence of ethylenically unsaturated functional groups in the radiation curable polyurethane. The ethylenically unsaturated functional groups may result from the ethylenically unsaturated compound used to form the radiation curable composition. In a preferred embodiment, curing of the radiation curable aqueous composition is performed by irradiation with UV light, optionally UV LED light or an electron beam (EB). Low energy curing (such as UV LED curing) is also possible. That is, the radiation curable aqueous composition after application to a surface can be irradiated with actinic radiation, typically by using UV light or by using an electron beam. A suitable type of radiation for curing the radiation curable composition according to the first aspect is UV light. Suitable wavelengths of UV light include 200-400 nm.

[0114] Typically suitable UV light sources emit light at wavelengths between 200 and 800 nm, with at least some radiation in the range of 200 to 400 nm.

[0115] The UV light source can be, for example, a UV light emitting diode (UV-LED), which typically emits in the spectrum with the strongest wavelengths ranging from 365 to 395 nm.

[0116] Any feature of any embodiment of the third aspect may be described independently as correspondingly described for any embodiment of any of the other aspects of the invention.

[0117] In a fourth aspect the present invention relates to the use of a coating according to an embodiment of the second aspect for consumer electronics, home appliances, automotive interiors and exteriors, packaging, such as cosmetic packaging, furniture, in-mold decoration, industrial applications, graphical applications or in-mold labelling, preferably for automotive interiors and exteriors, home appliances, consumer electronics or cosmetic packaging.

[0118] A particularly preferred use of coatings according to embodiments of the present invention is in automotive interiors and exteriors, preferably automotive interiors.

[0119] Any feature of any embodiment of the fourth aspect may be described independently as correspondingly described for any embodiment of any of the other aspects of the invention.

[0120] In a fifth aspect, the present invention relates to a method of forming an aqueous radiation curable composition according to an embodiment of the first aspect of the present invention, comprising the step of mixing a compound of a radiation curable polyurethane dispersion obtained by reacting a. a compound comprising at least two isocyanate groups, b. a polyol having a molecular weight of at least 500 g / mol, c. a compound comprising at least one group capable of reacting with an isocyanate group and preferably at least one hydrophilic group which comprises a salt or which may comprise a salt after reaction with a neutralizing agent, and d. an ethylenically unsaturated compound comprising at least one group capable of reacting with an isocyanate group and at least one ethylenically unsaturated group, with a plurality of polyurethane particles having a median size D50 of 1-10 μm and water.

[0121] The aqueous radiation curable compositions according to embodiments of the present invention can be prepared in a number of ways. The radiation curable polyurethane dispersion is typically provided in the form of an aqueous solution or dispersion. That is, the water and the radiation curable polyurethane dispersion can be provided from a mixture comprising water and the radiation curable polyurethane dispersion.

[0122] In an embodiment, the formation of the aqueous radiation curable composition comprises a first step comprising the reaction of compounds a., b., c. and d., optionally compound e. Herein, compounds a., b., c. and d. can be reacted together simultaneously or in a multi-step process. For example, compounds a., c. and optionally b. can be reacted first, and then compound d. Optionally, the method can further comprise a step of chain extension by reaction with compound f. The reaction step with compound f. is preferably carried out after reacting a., b., c. and d., optionally e., and compound f. reacts with any residual, i.e. unreacted, isocyanate groups. Thereby, a radiation curable polyurethane dispersion according to an embodiment of the present invention can be formed that is preferably free of unreacted isocyanate groups. Optionally, after cessation of the reaction, further ethylenically unsaturated compounds can be added. The residual isocyanate content is typically measured by isocyanate titration with an amine. NH 2 The amount of groups is typically obtained by calculation. The reaction can be carried out by adding 5-40% by weight, preferably 15-25% by weight, of a solvent to reduce the viscosity of the prepolymer. Preferably, the solvent is acetone or methyl ethyl ketone.

[0123] The radiation-curable polyurethane dispersion can then be reacted with a neutralizing agent to convert the hydrophilic groups to anionic salts, in embodiments where the hydrophilic groups provided by compound c. do not contain salts, but can contain salts. This can be done by adding an organic or inorganic neutralizing agent to the prepolymer or water. Suitable neutralizing agents include ammonia, volatile organic tertiary amines such as trimethylamine, triethylamine, triisopropylamine, tributylamine, N,N-dimethylcyclohexylamine, N,N-dimethylaniline, N-methylmorpholine, N-methylpiperazine, N-methylpyrrolidine and N-methylpiperidine, low volatility alcohol amines such as dimethylaminoethanol, triethanolamine, dimethylaminoethylpropanolamine, and non-volatile inorganic bases, including monovalent metal cations, preferably alkali metals such as lithium, sodium and potassium, and anions such as hydroxides, hydrides, carbonates and bicarbonates. Preferably, the neutralizing agent includes triethylamine and / or sodium hydroxide. The total amount of these neutralizing agents can be calculated according to the total amount of acid groups to be neutralized. In embodiments, the neutralizing agent is added in a stoichiometric ratio of neutralizing agent to acid groups, eg, protonated hydrophilic groups, of 0.5:1 to 1:1.

[0124] In embodiments, the radiation curable polyurethane dispersion is dispersed in water, for example by slowly adding the water-dispersible radiation curable polyurethane to water or conversely by adding water to the prepolymer. Typically, the dispersion is carried out using high shear mixing.

[0125] In embodiments, the neutralizing agent may be added before, during, or after the step of dispersing the water-dispersible radiation-curable polyurethane in water.

[0126] Typically, after formation of the prepolymer dispersion, if the dispersion contains a volatile, e.g. organic solvent, having a boiling point below 100° C., the solvent is removed from the dispersion. This can be done under reduced pressure relative to atmospheric pressure and at a temperature of 20 to 90° C., preferably 40 to 70° C.

[0127] In embodiments, the polyurethane particles are provided in powder form. In embodiments, the polyurethane particles are provided as a dispersion or suspension. For example, the polyurethane particles can be provided in water.

[0128] Compositions according to embodiments of the present invention can be prepared in various ways. In embodiments, the radiation curable polyurethane dispersion compound, polyurethane particles, water, optional additives and further compounds are blended and mixed. In embodiments, high shear mixing is used for mixing. In embodiments, mixing can be performed using a Cowles blade, preferably at a rotation speed of 20-2000 revolutions per minute. For example, mixing can be performed using, for example, a Cowles blade at a rotation speed of 20-2000 revolutions per minute under high shear at room temperature. Herein, the rotation speed can depend on the diameter of the Cowles blade, the diameter of the container and the volume to be mixed.

[0129] In embodiments, the mixing can result in an aqueous radiation curable composition in which the polyurethane particles are in suspension. In embodiments, an anti-settling agent can be added to the aqueous radiation curable composition to prevent settling of the polyurethane particles.

[0130] Any feature of any embodiment of the fifth aspect may be described independently as correspondingly described for any embodiment of any of the other aspects of the invention.

[0131] The present invention will now be described in detail with reference to the following non-limiting examples, which are for illustrative purposes only. Unless otherwise indicated, the parts referred to in the examples are parts by weight. EXAMPLES

[0132] Radiation curable and non-radiation curable polyurethane dispersions First radiation curable polyurethane dispersion (UV PUD1) UV PUD1 is the commercial product UCECOAT® 2804. It is a low-migration acrylated polyurethane translucent dispersion obtained from the reaction of a mixture of compound a., compound b., compound c., compound d. and compound e. It had a viscosity of 60 mPas, a solids content of 34.7 wt.%, a particle size of 96 nm and a pH of 7.2.

[0133] Second radiation curable polyurethane dispersion (UV PUD2) UV PUD2 is a radiation curable polyurethane dispersion obtained from the reaction of 262.1 g EBECRYL® 4744 (d.), 13.4 g neopentyl glycol (e.), 118.8 g polyester of neopentyl glycol, adipic acid and isophthalic acid (Mw 635, b.) and 35.1 g dimethylolpropionic acid (c.) with 0.3 g dibutyltin dilaurate, 133.9 g isophorone diisocyanate (a.) and 66.9 g hexamethylene diisocyanate (a.). The resulting prepolymer had a residual NCO of 0.5 meq NCO / g. Then 20.7 g triethylamine was added. Finally, 11.8 g ethylenediamine (f.) was added after the dispersion step. The final dispersion had a viscosity of 151 mPas, a solids content of 35.0 wt. %, a particle size of 46 nm and a pH of 7.9.

[0134] (Example 1c) Further non-radiation curable polyurethane dispersions Three dispersions containing additional water-dispersible non-radiation curable polyurethanes in water were used in the examples: Daotan® 6490 (PUD1), Daotan® 6491 (PUD2) and Daotan® 6493 (PUD3). Each of these dispersions is commercially available. The properties of these dispersions are summarized in Table 0 below. [Table 0]

[0135] Preparation of aqueous radiation curable compositions and coatings therefrom For the purposes of the examples, various compositions were prepared according to the following general procedures.

[0136] The aqueous radiation curable polyurethane dispersion was poured into a 250 mL plastic mixing container. Optionally, a non-radiation curable further polyurethane dispersion was added to the aqueous radiation curable polyurethane dispersion. The dispersion was stirred at 600 rpm with a Cowles mixer blade (5 / 8 inch). Next, water and then additives were added to the aqueous dispersion to obtain a mixture. In the examples, Additol® VXW390 and Additol® VXW6580 were added as wetting agents and Irgacure® 500 as photoinitiator. Finally, fillers, such as polyurethane particles or non-polyurethane particles, were added to the mixture. The mixture was stirred at 600 rpm for about 20 minutes. All steps were performed at room temperature. A Cowles blade is preferred as it ensures good dispersion of the polyurethane particles, thereby obtaining a composition according to an embodiment of the present invention.

[0137] The relative amounts of the various compounds, additives and fillers used in each composition are set forth in the examples below.

[0138] In the following examples, the compositions were used immediately after preparation to form coatings. For this purpose, each composition was applied to the surface of a plastic substrate (ABS: Magnum® 3616, ABS / PC: Bayblend® T85XF or T65XF). A bar coater was used to apply a coating of approximately 20 g / m 2 A dry film thickness (DFT) of 1000-1200 mJ / cm was targeted. The applied composition was dried at 60°C for 5 min. Then, curing with UV radiation was performed using two 120 W / cm Hg lamps (1000-1200 mJ / cm 2The lamp was passed once over the composition at a speed of 15 m / min (i.e., approximately 50 ft / min).

[0139] analysis technology A variety of analytical techniques were used to characterize the example compositions and coatings, and these techniques are described below.

[0140] Dynamic light scattering (DLS) measurements were used to characterize the hydrodynamic size of particles in various compositions. Prior to DLS measurements, the concentrated compositions were diluted with deionized distilled water, thereby obtaining a particle concentration of 0.05 w / w%. The diluted compositions were filtered. DLS measurements were then performed at 23°C using a Beckman-Coulter DelsaNano-c particle analyzer. The incident monochromatic light used in the DLS measurements had a wavelength of λ=658 nm. The scattered light was detected in a near backscattering configuration at an angle of 165°. The z-average particle size along with the polydispersity index was determined from the second-order cumulant analysis of the electric field autocorrelation function. The diffusion coefficient of the single particles was then estimated from the average decay constant. From there, the median particle size D50 could be obtained using the Stokes' relationship.

[0141] The solids content was determined gravimetrically. For radiation curable polyurethane dispersions, the gravimetric method involved drying for 2 hours at 120° C. For non-radiation curable further polyurethane dispersions, the gravimetric method involved drying for 3 hours at 125° C.

[0142] The pH was measured according to DIN EN ISO10390.

[0143] The viscosity of the radiation-curable polyurethane dispersion and the non-radiation-curable further polyurethane dispersion is measured in accordance with DIN EN ISO 3219 with a cone and plate rheometer MCR092 (Paar-Physica). -1 A constant shear rate of 200 µm was used at 23°C.

[0144] The coatings were tested for adhesion, soft feel and DEET resistance.

[0145] For the soft feel test, the example coatings were compared to a commercial WB 2k soft feel coating from General Motors. The example coatings were evaluated for their soft feel by three different observers. In the table, each coating is rated using a scale of 1 to 4, with 1 indicating good soft feel and 4 indicating poor soft feel. Preferably the coatings receive a score of 1 or 2.

[0146] The resistance, i.e., chemical resistance, of each of the example coatings to DEET and sunscreen was also determined according to General Motors sunscreen and insect repellent resistance test procedures, e.g., GMW14445. The GMW14445 test was performed at 80° C. The other tests were performed at room temperature and ambient humidity. Each coating is rated using a scale of 1 to 4, with 1 indicating good resistance and 4 indicating poor resistance. Preferably the coating receives a score of 1.

[0147] The adhesion (ADH) of the coating to the surface of the plastic substrate is evaluated using a cross-hatch test. In each case, the coating is first cut with a knife into 5 parallel cuts approximately 1 cm long and spaced approximately 1 mm apart. Then, 5 parallel cuts are made transversely, approximately 1 cm long and spaced approximately 1 mm apart. An adhesive tape (Scotch®) is then pressed firmly onto the cross-cut coating and rapidly removed. Damage to the cross-cut surface area of ​​the coating, i.e. due to loss of adhesion, is expressed on a scale of 0 to 5, with 5 = best adhesion. Good adhesion is preferred to ensure a strong, permanent bond between the coating and the surface.

[0148] Coatings and Compositions The weight part content of a series of compositions according to a preferred embodiment of the present invention and the analysis of a series of coatings formed therefrom are summarized in Table A. Tables D, F, and H list the fillers used. Each of the coatings summarized in this table has a score of 1 for both soft feel and chemical resistance, i.e., to sunscreen and DEET.

[0149] Coatings and compositions with various concentrations of curable polyurethane and non-curable additional polyurethane In a further example, the effect of the amount of PUD1 in the composition on the properties of the coating was tested. Table B summarizes the content in parts by weight of a series of compositions and the analysis results of a series of coatings formed therefrom. Tables D and F list the fillers used. The last two columns of the table show the weight percent of radiation curable polyurethane and non-radiation curable polyurethane as a percentage of the total of radiation curable polyurethane and non-radiation curable polyurethane. For UV PUD1, it can be observed that the soft feel is the best when the composition for forming the coating contains PUD1. However, the amount of PUD1 added is preferably not too high. For example, the weight ratio of UV PUD1 to PUD is at least 1.5.

[0150] Coatings and compositions with various types of non-radiation curable further polyurethane compounds In further examples, the effect of the type of PUD in the composition on the properties of the coating was examined. The parts by weight content of a series of compositions and the analytical results of a series of coatings formed therefrom are summarized in Table C. For each PUD used in the examples, both soft feel and chemical resistance are favorable.

[0151] Coatings and Compositions in Which Various Types of Polyurethane Particles are Used In further examples, the effect of polyurethane particle characteristics on the properties of the coatings was examined. Table D summarizes the characteristics of the various polyurethane particles examined. In this specification, D50 is the median particle size (μm). The content in parts by weight of a series of compositions and the analytical results of a series of coatings formed therewith are summarized in Table E. It can be observed from the examples that when the particles are in the range of 1-10 μm, in particular the soft feel is in the preferred range.

[0152] Coatings and compositions using various types of polymethylurea resin particles In further examples, the effect of using different types of particles on the properties of the coatings was tested. Table F summarises the characteristics of the different particles used in the examples. In this specification, D50 is the median particle size (μm). The content in parts by weight of a series of compositions and the analytical results of a series of coatings formed therewith are summarised in Table G. It can be observed that the results of polyurethane particles are better than those of polymethylurea resin particles. When mixtures containing at least polyurethane particles are used, the results are similarly favourable.

[0153] Coatings and compositions with various types of non-polyurethane particles The effect of using different types of particles on the properties of the coating was further tested. Table H summarizes the characteristics of the different particles tested. In this specification, D50 is the median particle size (μm) and SC indicates the solid content in the form in which the filler is provided by the manufacturer. The content in parts by weight of a series of compositions and the analytical results of a series of coatings formed therewith are summarized in Table I. It can be observed that the results of polyurethane particles are better than those of other particles even when the diameter distribution is similar. This clearly shows the advantageous effect of using polyurethane particles used in the present invention.

[0154] Coatings and compositions using polyurethane particles at various concentrations In further examples, the effect of using different amounts of polyurethane particles on the properties of the coating is examined. The content of parts by weight of a series of compositions and the analytical results of a series of coatings formed therewith are summarized in Table J. For compositions containing more than 20% by weight of polyurethane particles, the cosmetic properties and uniformity of the coating are poor. This corresponds to a weight ratio of polyurethane particles to the sum of the non-radiation curable further polyurethane dispersion and the radiation curable polyurethane dispersion exceeding 1.0. As mentioned in Table D, Addimat® 8FT is provided in water and has a solid content of 36% by weight. Thus, 10 parts by weight of Addimat® 8FT in composition F13, as mentioned in Table E, is equivalent to 3.6% by weight of polyurethane particles in composition F13. Thus, from these examples, it is assumed that the most favorable results are obtained when the polyurethane particle content of the composition is 3-20% by weight, or the weight ratio of polyurethane particles to the sum of the water-dispersible non-radiation curable further polyurethane dispersion and the radiation curable polyurethane dispersion is 0.08-1.0.

[0155] [Table A]

[0156] [Table B]

[0157] [Table C]

[0158] [Table D1]

[0159] [Table D2]

[0160] Table E

[0161] Table F

[0162] Table G

[0163]

Table H

[0164]

Table I

[0165]

Table J

Claims

1. An aqueous radiation curable composition comprising: Radiation-curable polyurethane dispersions obtained by reacting: a. a compound containing at least two isocyanate groups; b. a polyol having a molecular weight of at least 500 g / mol; c. a compound comprising at least one group capable of reacting with an isocyanate group and at least one hydrophilic group; and d. an ethylenically unsaturated compound containing at least one group capable of reacting with an isocyanate group and at least one ethylenically unsaturated group; a plurality of polyurethane particles that are non-radiation curable and have a median particle size D50 of 1 to 10 μm; and ·water.

2. 2. The composition according to claim 1, wherein the radiation-curable polyurethane dispersion is obtained by reacting 10 to 60 parts by weight of compound a., 1 to 40 parts by weight of compound b., 2 to 25 parts by weight of compound c., and 15 to 85 parts by weight of compound d., wherein the parts by weight of compounds a., b., c. and d. total 100.

3. 2. The composition according to claim 1, wherein the compounds reacted to obtain the compound of the radiation-curable polyurethane dispersion additionally comprise compound e., which is a diol having a molecular weight of up to 400 g / mol.

4. 2. The composition of claim 1, wherein the compounds reacted to obtain the radiation-curable polyurethane dispersion additionally comprise a compound f. comprising at least two amino groups independently selected from primary and secondary amino groups.

5. 2. The composition of claim 1, wherein the polyol compound b. is a polyester or a polycarbonate.

6. 2. The composition according to claim 1, wherein the polyurethane particles have a median diameter D50 of 5 to 8 μm.

7. 2. The composition according to claim 1, further comprising a non-radiation curable aqueous polyurethane dispersion obtained by reacting i. a compound containing at least two isocyanate groups; ii. a polyol having a molecular weight of at least 500 g / mol; iii. A compound comprising at least one group capable of reacting with an isocyanate group and at least one hydrophilic group; and iv. A compound containing at least two amino groups selected from a primary amino group and a secondary amino group.

8. 8. The composition according to claim 7, wherein the non-radiation-curable further polyurethane dispersion represents 0.1 to 40% by weight of the sum of the masses of the non-radiation-curable further polyurethane dispersion, the radiation-curable polyurethane dispersion and the polyurethane particles.

9. 8. The composition according to claim 7, wherein the compound to be reacted to obtain the non-radiation curable further polyurethane dispersion additionally comprises compound v., which is a diol having a molecular weight of less than 500 g / mol.

10. 8. The composition of claim 7, wherein the polyol compound ii. is a polyester or a polyether.

11. 9. The composition of claim 8, wherein the weight ratio of the radiation curable polyurethane dispersion to the non-radiation curable further polyurethane dispersion in the composition is at least 1.

5.

12. The composition according to claim 1 , wherein the plurality of polyurethane particles constitutes 3 to 20% by weight of the composition as a solid content.

13. 10. The composition of claim 1 further comprising at least one of the following additives: a catalyst, a polymerization inhibitor, or a photoinitiator.

14. Polyurethane particles T ｇ The composition of claim 1, wherein the temperature is up to 0°C.

15. 10. The composition of claim 1, wherein the polyurethane particles have an oil absorption of up to 120 grams of oil per 100 grams of polyurethane particles.

16. A coating formed by curing the composition of any one of claims 1 to 15.

17. A method comprising the steps of: applying the composition to a surface; Curing the composition, thereby forming a coating.

20. A method of forming the coating of claim 16 comprising:

18. 17. Use of the coating according to claim 16 for consumer electronics, home appliances, automotive interiors and exteriors, packaging, furniture, in-mold decoration, industrial applications, graphical applications or in-mold labelling.

19. 16. A method of forming the aqueous radiation curable composition of claim 1, comprising mixing: Compounds of radiation-curable polyurethane dispersions obtained by reacting: a. a compound containing at least two isocyanate groups; b. a polyol having a molecular weight of at least 500 g / mol; c. a compound comprising at least one group capable of reacting with an isocyanate group and at least one hydrophilic group; and d. an ethylenically unsaturated compound containing at least one group capable of reacting with an isocyanate group and at least one ethylenically unsaturated group; a plurality of polyurethane particles that are non-radiation curable and have a median diameter D50 of 1 to 10 μm; and ・Water.

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