CN117580880A

CN117580880A - Water-based radiation curable compositions for soft feel applications

Info

Publication number: CN117580880A
Application number: CN202280045694.3A
Authority: CN
Inventors: J·麦克朗; M·胡钦斯; E·西班德
Original assignee: Zhanxin America Co ltd
Current assignee: Zhanxin America Co ltd
Priority date: 2021-07-02
Filing date: 2022-06-09
Publication date: 2024-02-20

Abstract

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

Description

Water-based radiation curable compositions for soft feel applications

Technical Field

The present invention relates to water-based radiation curable compositions, coatings comprising said compositions, methods of forming said coatings and the use of said coatings for coating applications, more particularly for applications in soft sensing applications, such as for automotive interior trim.

Background

The coating may protect the surface from damage caused by chemicals and/or abrasion. The soft feel coating may also have the ability to convert the sometimes unattractive touch of a surface (e.g., a plastic surface) into a pleasant rubber-like, leather-like or velvet-like touch. Thus, manufacturers may use relatively inexpensive materials such as plastics and apply coatings to give them the appearance of high-end luxury goods. The coating may provide a consumer with a high quality and even luxurious appearance. There is an increasing demand for soft feel coatings. Such coatings may be used in a variety of applications including consumer electronics (e.g., notebook computers, cell phone cases), appliances (e.g., ovens, coffee machines), automotive interiors (e.g., panels, brackets, armrests), packaging (e.g., cosmetic bottles/bottle caps, bags), and textured films for in-mold decoration/in-mold labeling (IMD/IML).

Soft feel coatings currently used in automobiles can be formed from two-part conventional aqueous compositions. Such soft feel coatings typically do not have the chemical resistance that may be required, particularly for sunscreens and insect repellents (e.g., N-diethyl-m-toluamide, DEET). Instead, the desired chemical resistance is provided by a primer layer located under the soft feel coating. Providing a primer layer requires additional time and cost.

Solvent-based curable compositions (solvents are typically volatile organic compounds) are commercially available (e.g., commercial compositions8896 and->8894). However, solvent-based compositions generally do not provide the soft feel required for automotive interior trim.In addition, the coatings formed therefrom do not pass the required chemical tests, i.e. do not have the required chemical resistance. Solvent-based curable compositions also suffer from regulatory concerns. For example, the solvent is generally a volatile organic compound, which is not preferable from the viewpoint of sustainability.

The market is currently seeking improvements over traditional coatings due to the poor chemical and scratch resistance of existing coatings. The introduction of aqueous UV technology may radically change the soft touch market.

Thus, there remains a need in the art for aqueous coating compositions having good soft feel properties and chemical resistance.

Disclosure of Invention

It is therefore an object of the present invention to develop radiation curable compositions and coatings formed from said compositions which at least partially overcome some of the above-mentioned disadvantages.

The compositions of embodiments of the present invention and coatings formed from the compositions may have one or more of the following advantages:

the compositions of the embodiments can be easily applied, for example, compared to prior art two-component aqueous compositions. In particular, it may not be necessary to apply a primer layer to the surface prior to applying the composition to the surface. Thus, the method of applying the composition may be simple and cost effective. The application of the composition generally does not require advanced equipment such as a two-component spray gun.

Volatile organic compounds (e.g., organic solvents) are generally not required in the composition. Furthermore, the amount of unreacted (i.e., free) isocyanate groups in the composition may be low. From a regulatory point of view, this may make the composition a sustainable and safe choice. Furthermore, the absence of reactive free isocyanate groups generally increases the lifetime, i.e. pot life, of the composition.

Larger batches can be prepared as the lifetime (i.e. pot life) of the composition may be increased. This may further reduce costs.

The composition may have a good spray viscosity. Furthermore, a coating layer may be formed from the composition at a low temperature.

Unlike conventional water-based compositions, the compositions of embodiments of the present invention may be free of formaldehyde, alkylphenol ethoxylates (APEO), N-methylpyrrolidone (NMP), or N-ethylpyrrolidone (NEP).

Since the composition is radiation curable, the time required to cure the composition to form a coating can be very short. For example, the curing may take seconds or less instead of hours.

The composition may provide a coating with a soft feel. Furthermore, the composition may provide coatings with good chemical stability and good to excellent chemical resistance, in particular chemical resistance against sunscreens and insect repellents, such as N, N-diethyl meta-toluamide (DEET).

The composition of the invention at all can provide coatings with good adhesion properties.

In a first aspect, the present invention relates to an aqueous (waterborne) radiation curable composition comprising an aqueous radiation curable polyurethane dispersion (also referred to as radiation curable polyurethane dispersion), a plurality of non-radiation curable polyurethane particles having a median particle diameter D50 of from 1 to 10 μm, and water, said aqueous radiation curable polyurethane dispersion being obtained by reacting: a. a compound comprising at least two isocyanate groups, b a polyol having a molecular weight of at least 500g/mol, c a compound comprising at least one group reactive with isocyanate groups and at least one hydrophilic group (preferably comprising a salt, or being able to comprise a salt after reaction with a neutralising agent), d an ethylenically unsaturated compound comprising at least one group reactive with isocyanate groups and at least one ethylenically unsaturated group.

In a second aspect, the present invention relates to a coating formed by curing the composition of the embodiments of the first aspect.

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

In a fourth aspect, the present invention relates to the use of the coating of the embodiment of the second aspect for consumer electronics, appliances, automotive interior and exterior trim, packaging, furniture, in-mold trim, industrial applications, graphic applications or in-mold labeling.

In a fifth aspect, the present invention relates to a method of forming an aqueous radiation curable composition of any embodiment of the first aspect of the invention, comprising mixing a radiation curable polyurethane dispersion compound, a plurality of polyurethane particles which are not radiation curable and have a median particle diameter D50 of from 1 to 10 μm, and water, wherein the radiation curable polyurethane dispersion compound is obtained by reacting: a. a compound comprising at least two isocyanate groups, b a polyol having a molecular weight of at least 500g/mol, c a compound comprising at least one group reactive with isocyanate groups and at least one hydrophilic group (preferably comprising a salt, or being able to comprise a salt after reaction with a neutralising agent), d an ethylenically unsaturated compound comprising at least one group reactive with isocyanate groups and at least one ethylenically unsaturated group.

In the context of the present invention, an ethylenically unsaturated compound is a compound having at least one ethylenically unsaturated functional group. Ethylenically unsaturated functional groups are generally suitable for free radical polymerization, i.e., free radical polymerization. In the context of the present invention, an "ethylenically unsaturated functional group" may refer to a group having at least one carbon-carbon double bond (i.e. pi bond) which may undergo free radical polymerization under the influence of radiation and/or an activated (photo) initiator. The polymerizable ethylenically unsaturated functional groups are generally selected from allyl, vinyl and (meth) acryl groups. Alternatively or additionally, the double bond may be derived from, for example, an unsaturated acid, an unsaturated fatty acid or acrylamide. In a preferred embodiment, the ethylenically unsaturated compound is a (meth) acrylated compound. Here, the (meth) acrylic acid (esterified) compound is a compound containing 1 or more (meth) acryloyl groups.

In the context of the present invention, the term (meth) acrylic compound is understood to meanCapping the acrylated and methacrylated compounds or derivatives thereof and mixtures thereof. In the context of the present invention, the term (meth) acrylic is intended to cover both acrylic and methacrylic compounds. In a preferred embodiment, the (meth) acrylated compound is an acrylated compound. Such compounds may comprise at least one acrylic acid (CH ₂ =chcoo-) and/or methacrylic acid (CH ₂ ＝CCH ₃ COO-) groups. Compounds containing only one (meth) acrylic functional group are preferred.

In the context of the present invention, the term "(meth) acrylic" encompasses acrylic and/or methacrylic groups present on the compound either alone or as a mixture of acrylic and methacrylic groups.

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/water-dispersible compound" is a compound that is insoluble in water but is capable of dispersing into water and forming a water-dispersible compound (i.e., an aqueous dispersion) without the use of a separate auxiliary agent (e.g., an emulsifier or dispersant). That is, upon dispersion, it forms a stable two-phase system of small discrete particles or droplets dispersed in water. For example, in "polyurethane dispersions", the discrete particles are polyurethane polymers. The particles are the dispersed or internal phase and the aqueous medium is the continuous or external phase. By "stable" is meant herein that after 1 day at 60 ℃, preferably it is substantially free of coalescence (droplets) or flocculation (particles) that result in phase separation, emulsification or precipitation of the heterogeneous system after even more than 2 days, typically more than 4 days, most preferably even after 10 days at 60 ℃.

In the context of the present invention, the term "polyol" means a compound comprising two or more hydroxyl groups per molecule.

In the context of the present invention, the term "polyamine" means a compound comprising two or more primary or secondary amine groups per molecule.

In a first aspect, the present invention relates to an aqueous radiation curable composition comprising a radiation curable polyurethane dispersion, a plurality of non-radiation curable polyurethane particles having a median particle diameter D50 of from 1 to 10 μm and water, said radiation curable polyurethane dispersion being obtained by reacting: a. a compound comprising at least two isocyanate groups, b a polyol having a molecular weight of at least 500g/mol, c a compound comprising at least one group reactive with isocyanate groups and at least one hydrophilic group (preferably comprising a salt, or being able to comprise a salt after reaction with a neutralising agent), d an ethylenically unsaturated compound comprising at least one group reactive with isocyanate groups and at least one ethylenically unsaturated group.

In an embodiment of the first aspect, the radiation curable polyurethane dispersion is obtained by reacting 10 to 60 parts by mass of compound a, 1 to 40 parts by mass of compound b, 2 to 25 parts by mass of compound c, and 15 to 85 parts by mass of compound d, wherein the parts by mass of compounds a, b, c, and d total 100. Preferably, at least 15 parts by mass, for example at least 20 parts by mass, of compound a is present in the reaction. Preferably, up to 50 parts by mass of compound a, more typically up to 40 parts by mass of compound a, are present in the reaction. Preferably, 10 to 50 parts by mass, for example 20 to 40 parts by mass, of compound a is present in the reaction. In some embodiments, at least 80wt%, preferably at least 85wt%, more preferably at least 90wt% of the compounds that react to form the radiation curable polyurethane dispersion consist of compounds a, b, c and d. In some embodiments, at least 80wt%, preferably at least 85wt%, more preferably at least 90wt% of the compounds that react to form the radiation curable polyurethane dispersion consist of compounds a, b, c, d, e (if present) and f (if present).

In an embodiment of the invention, compound a comprises an organic compound comprising at least two, for example 2-6 isocyanate groups. Namely, the compound a is a polyisocyanate compound. In some embodiments, compound a comprises only two or three isocyanate groups, preferably only two isocyanate groups. In some embodiments, compound a is selected from aliphatic, cycloaliphatic, aromatic, and/or heterocyclic polyisocyanates or combinations thereof. In some embodiments, compound a contains allophanate groups, biuret groups, and/or isocyanurate groups.

In some embodiments, the aliphatic or cycloaliphatic polyisocyanate is at least one of 1,5 diisocyanato pentane, 1,6 diisocyanatohexane (HDI), 1' -methylenebis [ 4-isocyanatocyclohexane ] (H12 MDI), 5-isocyanato-1-isocyanatomethyl-1, 3-trimethyl-cyclohexane (isophorone diisocyanate, IPDI), or Pentamethylene Diisocyanate (PDI). Aliphatic polyisocyanates containing more than two isocyanate groups are, for example, derivatives of the abovementioned diisocyanates, such as 1, 6-diisocyanatohexane biuret and isocyanurate. Examples of aromatic polyisocyanates are 1, 4-diisocyanatobenzene (BDI), 2, 4-diisocyanatotoluene (2, 4-TDI), 2, 6-diisocyanatotoluene (2, 6-TDI), 1' -methylenebis [ 4-isocyanatobenzene ] (MDI), xylylene Diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), 1, 5-Naphthalenediisocyanate (NDI), benzidine diisocyanate (TODI) and p-phenylene diisocyanate (PPDI).

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. Particular preference is given to 1,1' -methylenebis [ 4-isocyanatocyclohexane ] (H12 MDI) and/or isophorone diisocyanate (IPDI).

In some embodiments, compound a comprises a mixture of compounds described with respect to compound a.

Preferably, the amount of polyol compound b used to prepare the radiation curable polyurethane dispersion is 1 to 40 parts by mass.

In some embodiments, polyol compound b may be selected from polyols having a number average molecular weight of at least 500 g/mol. In some embodiments, compound b has a number average molecular weight of at most 5,000g/mol, preferably at most 2,000g/mol, more preferably at most 1,000g/mol, calculated based on the hydroxyl index of the polyol. Here, the hydroxyl group index may be calculated using the formula 56×2×1000/(hydroxyl value of polyol). In some embodiments, polyol compound b includes at least one of polyester polyols, polyether polyols, polycarbonate polyols, fatty dimer diols, and polyacrylate polyols, and combinations thereof.

In some embodiments, the polyether polyol comprises at least one of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, or a block copolymer thereof.

In some embodiments, the fatty dimer diol is obtained from the hydrogenation of dimer acid, preferably dimer acid containing 36 carbon atoms.

In some embodiments, the polyacrylate polyol may be formed by free radical polymerization of (meth) acrylic acid and/or (meth) acrylamide monomers, preferably initiated by a thermal free radical initiator. The formation is preferably carried out in the presence of a hydroxylated thiol. The formation may be followed by transesterification of the end groups with a diol, such as 1, 4-butanediol.

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

Preferably, the polyol compound b is a polyester polyol. In some embodiments, the polyester polyol is the hydroxyl-terminated reaction product of a polyol (preferably a diol) and a polycarboxylic acid (preferably a dicarboxylic acid) or their corresponding anhydride. In some embodiments, the polyester polyol is obtained from ring opening polymerization of a lactone. Preferably, the polycarboxylic acids used to form the polyester polyols are aliphatic, cycloaliphatic, aromatic and/or heterocyclic, and they may be substituted, saturated or unsaturated. Examples of dicarboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, hexahydrophthalic acid, isophthalic acid, terephthalic acid, phthalic acid, tetrachlorophthalic acid, 1, 5-naphthalene dicarboxylic 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 also contain air-drying components (air drying component), for example long-chain unsaturated fatty acids, in particular fatty acid dimers.

Preferably, the polyol used to prepare the polyester polyol is selected from one or more diols as described for the embodiments of diol compound e.

In a preferred embodiment, the polyester polyol is prepared predominantly from the polycondensation of (1) neopentyl glycol with (2) adipic acid and/or isophthalic acid.

In embodiments where compound b is a polycarbonate polyol, compound b may be the reaction product of a diol (e.g., 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, dialkyl carbonates such as dimethyl carbonate, diaryl carbonates such as diphenyl carbonate, or cyclic carbonates such as ethylene carbonate or propylene carbonate.

In some embodiments, compound b may comprise a mixture of compounds described with respect to compound b.

Compound c is typically a compound comprising at least one hydrophilic group capable of dispersing the radiation curable polyurethane in an aqueous medium, for example a saturated organic compound. In some embodiments, the radiation curable polyurethane may be directly dispersible, for example when the hydrophilic groups are not ionic or salt. In alternative embodiments, the radiation curable polyurethane may be dispersible after reaction with a neutralizing agent to provide a salt. In some embodiments, the hydrophilic groups that enable the polyurethane to be dispersible in aqueous media may be ionic or nonionic. Preferably, the hydrophilic group is an ionic group, more preferably an anionic group, most preferably an acidic group, or a corresponding salt. In some embodiments, the acidic group is a carboxylic acid, sulfonic acid, or phosphonic acid group. In some embodiments, the salt comprises a counter ion and a carboxylate, sulfonate, or phosphonate. Examples of suitable counter ions for the salts are ammonium, trimethylammonium, triethylammonium, sodium, potassium, lithium and the like. The nonionic group can comprise a hydrophilic moiety including polyethylene oxide, polypropylene oxide, or block copolymers made therefrom. Preferably, the hydrophilic groups comprise carboxylic acid groups and/or salts thereof. Compound c is typically a hydrophilic compound.

In some embodiments, the at least one group that is reactive with isocyanate groups may be selected from hydroxyl groups, primary amino groups, and secondary amino groups. In some embodiments, compound c is a hydroxylated and/or aminated compound. In some embodiments, 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.

In a preferred embodiment, compound c comprises a saturated hydroxycarboxylic acid comprising at least one hydroxyl group and at least one carboxylic acid group. In some embodiments, the number of hydroxyl groups in compound c is two or three. In some embodiments, 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, the compound c comprises aliphatic saturated mono-, di-and/or tri-carboxylic acids having at least one hydroxyl group per molecule or mixtures thereof.

In a preferred embodiment, compound c comprises an aliphatic saturated monocarboxylic acid containing at least one, for example at least two, hydroxyl groups. In some embodiments, the saturated aliphatic hydroxycarboxylic acid is represented by the general formula (HO) xR (COOH) y, wherein R represents a straight or branched hydrocarbon moiety having 1 to 12 carbon atoms, x is an integer from 1 to 3, and y is an integer from 1 to 3. In some embodiments, the sum of x+y is at most 5. In some embodiments, the hydroxycarboxylic acid includes at least one of citric acid, maleic acid, lactic acid, or tartaric acid. Preferably, y=1 in the above formula. In a preferred embodiment, the hydroxycarboxylic acid comprises an α, α -dimethylol alkanoic acid wherein x=2 and y=1 in the above formula, such as 2, 2-dimethylol propionic acid and/or 2, 2-dimethylol butyric acid.

Compound c may comprise at least one compound c as described above. Compound c may comprise a mixture of at least two compounds c as described above.

In some embodiments, the aqueous radiation curable composition of the present invention is an aqueous dispersion. In some embodiments, compound c is used in an amount sufficient to render the radiation curable polyurethane water dispersible. In some embodiments, the amount of compound c used to synthesize the radiation curable polyurethane dispersion is from 2 to 25 parts by mass, wherein the parts by mass of compounds a, b, c, and d total 100. In the embodiment in which the hydrophilic group is an ionic group, the amount of the compound c is preferably 3 to 10 parts by mass, more preferably 3.5 to 8 parts by mass. In the embodiment in which the hydrophilic group is a nonionic group, the amount of the compound c is preferably 5 to 25 parts by mass, more preferably 10 to 20 parts by mass.

In some embodiments, the ethylenically unsaturated compound d comprises at least one (meth) acrylic group. The ethylenically unsaturated groups (e.g. in the (meth) acryl group) may be introduced into compound d via side groups (i.e. pendant groups) in the terminal and/or backbone of compound d.

In some embodiments, compound d is selected from compounds containing at least one acrylic and/or methacrylic group. In some embodiments, compound d comprises two or more nucleophilic groups (typically hydroxyl groups) that are reactive with isocyanate. Examples of such compounds d are polyester (meth) acrylates containing hydroxyl groups, polyether ester (meth) acrylates containing hydroxyl groups and/or polyepoxy (meth) acrylates containing hydroxyl groups. In some embodiments, compound d is an acrylate. In some embodiments, compound d comprises at least one linear compound comprising an average of 2 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 2 or more (typically an average of 2) hydroxyl groups. Preferably, compound d comprises an aliphatic compound.

Preferably, the 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) which is reactive with isocyanate. More preferably, compound d comprises a (meth) acryloyl monohydroxy compound, such as a poly (meth) acryloyl monohydroxy compound. Preferably, compound d comprises an acrylate. In some embodiments, compound d comprises a mixture of at least two of the above compounds.

In an alternative embodiment, compound d comprises the esterification product of an aliphatic and/or aromatic polyol, preferably an aliphatic polyol, with (meth) acrylic acid having a residual average hydroxyl functionality of from 0.9 to 1.1, preferably from 0.95 to 1.05. 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 some embodiments, compound d comprises the reaction product of a polyol with ethylene oxide and/or propylene oxide or mixtures thereof. In some embodiments, compound d comprises the reaction product of a polyol with a lactone, which can undergo a ring opening reaction with the polyol. In some embodiments, the lactone comprises at least one of gamma-butyrolactone, delta-valerolactone, and epsilon-caprolactone, preferably delta-valerolactone and epsilon-caprolactone. Preferably, the alkoxylated polyol has up to three alkoxy groups per hydroxyl function and comprises epsilon-caprolactone. Preferably, the polyol is partially esterified with acrylic acid, methacrylic acid or mixtures thereof until the preferred residual hydroxyl functionality is obtained.

Preferably, compound d comprises at least two (meth) acryl functionalities, such as glycerol diacrylate, trimethylolpropane diacrylate, glycerol diacrylate, pentaerythritol triacrylate, di (trimethylolpropane) triacrylate, dipentaerythritol pentaacrylate, and (poly) ethoxylated and/or (poly) propoxylated equivalents of these (any of the foregoing).

In some embodiments, compound d is obtained from the reaction of (meth) acrylic acid with an aliphatic, cycloaliphatic, or aromatic compound having an epoxy functionality and at least one (meth) acrylic functionality. In some embodiments, compound d is obtained from the reaction of an aliphatic, cycloaliphatic or aromatic acid with an epoxy group-containing (meth) acrylate (e.g., glycidyl (meth) acrylate).

Other suitable compounds which can be used as compound d are (meth) acrylates with linear and branched polyols, wherein at least one hydroxyl function remains free to react with isocyanate groups, for example hydroxyalkyl (meth) acrylates containing alkyl groups of 1 to 20 carbon atoms. For example, the compound d may include at least one of hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate.

In some embodiments, compound d may comprise at least one compound described for compound d, e.g., a mixture of the compounds.

In some embodiments, the adduct comprises functional groups of both compound a and compound d, i.e., both compound a and compound d. The adducts may be formed by reacting an excess of one or more compounds a with one or more compounds d. In another embodiment of the invention, compound a and compound d are provided as separate molecules.

In some embodiments, the amount of compound d used to synthesize the radiation curable polyurethane is 15 to 85 parts by mass, preferably 15 to 70 parts by mass, more preferably 22 to 70 parts by mass, most preferably 30 to 60 parts by mass, wherein the parts by mass of compounds a, b, c and d add up to 100. If compound a and compound d are included in the adduct, the amount of the adduct used to synthesize the radiation curable polyurethane may be in the range of the sum of the lower limits of a and d as the lower limit and the sum of the upper limits of a and d as the upper limit.

In an embodiment of the first aspect, the compound that reacts to obtain the radiation curable polyurethane dispersion compound further comprises compound e: diols having a molecular weight of up to 400 g/mol. In some embodiments, the parts by mass of compounds a, b, c and d total 100, and the amount of compound e added is 0 to 5 parts by mass, for example 1 to 5 parts by mass.

In some embodiments, compound e comprises at least one of the following compounds: ethylene oxide adducts or propylene oxide adducts of 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, 4-trimethyl-1, 3-pentanediol, 1, 4-cyclohexanedimethanol, bisphenol A or hydrogenated bisphenol A, or mixtures thereof. In some embodiments, compound e comprises at least one of the following compounds: glycerol, trimethylolethane, trimethylolpropane, di (trimethylolethane), di (trimethylolpropane) and pentaerythritol and/or dipentaerythritol.

In an embodiment of the first aspect, the compound that reacts to obtain the radiation curable polyurethane dispersion additionally comprises a compound f: a compound comprising at least two amino groups independently selected from primary and secondary amino groups. In some embodiments, compound f has a molecular weight of up to 200 g/mol. Compound f may act as a chain extender.

The chain-extended polyamines generally have an average functionality of 2 to 4, more preferably 2 to 3. The compounds f are preferably water-soluble aliphatic, cycloaliphatic, aromatic or heterocyclic primary and/or secondary polyamines or hydrazines having up to 60, preferably up to 12, carbon atoms.

The amount of compound f added in the reaction to form the radiation-curable polyurethane may be determined from the amount of residual (i.e. unreacted) isocyanate groups present in the radiation-curable polyurethane prepolymer. Herein, the radiation curable polyurethane prepolymer is a compound obtained by reacting compounds a, b, c and d and possibly e (before reacting with compound f). In some embodiments, compound f is added after reacting compounds a, b, c, and d, and possibly e. In some embodiments, the ratio of amine groups in compound f to isocyanate groups (in terms of the number of functional groups) in the prepolymer obtained after reaction of compounds a, b, c and d and optionally e is from 0.25 to 1.2, preferably from 0.5 to 0.95. The residual isocyanate content is generally measured by isocyanate titration with an amine. The amount of amine groups is typically calculated. In embodiments in which compound f is reacted to give a radiation curable polyurethane, compound f may be added in an amount of from 0.1 to 10 parts by mass, preferably from 0.1 to 5 parts by mass, wherein the sum of the parts by mass of all compounds reacted to give the radiation curable polyurethane is 100. In some embodiments, the parts by mass of compounds a, b, c and d total 100, and the amount of compound f added is 1 to 15 parts by mass, preferably 1 to 10 parts by mass, more preferably 1 to 5 parts by mass.

In some embodiments, 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-trimethyl-cyclohexane), aminoethylethanolamine, polyvinylamine, polyoxyethylene and polyoxypropylene amines (e.g., jeffamines from Huntsman), and mixtures thereof.

In some embodiments, the composition comprises an additional ethylenically unsaturated compound. Additional ethylenically unsaturated compounds may be added to the composition before, during, or after the dispersion of the water-dispersible radiation-curable polyurethane. Typically, additional ethylenically unsaturated compounds are not reacted as part of the radiation curable polyurethane dispersion. For example, additional ethylenically unsaturated compounds are added to the composition only after the radiation curable polyurethane dispersion is formed. In embodiments comprising a water-dispersible non-radiation-curable further polyurethane, the further ethylenically unsaturated compound is not reacted as part of the water-dispersible radiation-curable further polyurethane. In other words, typically, the unreacted additional olefinically unsaturated compound is part of the composition. In some embodiments, the additional ethylenically unsaturated compound does not contain functional groups that can react with isocyanate groups. In these embodiments, the additional ethylenically unsaturated compound may be added prior to or during the step of reacting compounds a, b, c and d. Better dispersion stability is generally obtained when additional ethylenically unsaturated compounds are added before dispersing the radiation curable polyurethane dispersion in water. In some embodiments, the additional ethylenically unsaturated compound is different from compound d. In some embodiments, the additional ethylenically unsaturated compound is also a (meth) acrylated compound.

In some embodiments, the additional ethylenically unsaturated compound is independently selected from the (meth) acrylated compounds described above for compound d. In some embodiments, the additional ethylenically unsaturated compound may be any compound that is ethylenically unsaturated and does not contain functional groups that can react with isocyanate groups.

In some embodiments, the additional ethylenically unsaturated compounds include aliphatic and aromatic polyols, which have preferably been (meth) acrylated. Thus, preferably, the additional ethylenically unsaturated compound does not contain residual hydroxyl functionality. Preferably, the further ethylenically unsaturated compound is the esterification product of (meth) acrylic acid with a triol, tetraol, pentaol and/or hexaol or mixtures thereof. In some embodiments, the additional ethylenically unsaturated compound is the reaction product of a tri-, tetra-, penta-, and/or hexahydric polyol with ethylene oxide and/or propylene oxide or mixtures thereof. In some embodiments, the additional olefinically unsaturated compound is the reaction product of a tri-, tetra-, penta-, and/or hexahydric polyol with a lactone. Ethylene oxide, propylene oxide and lactones may undergo ring opening reactions with polyols. In some embodiments, the lactone is gamma-butyrolactone, delta-valerolactone or epsilon-caprolactone, preferably delta-valerolactone or epsilon-caprolactone. In a preferred embodiment, the polyol is an alkoxylated polyol having no more than two alkoxy groups per hydroxyl functionality, or a polyol modified with epsilon-caprolactone. Preferably, the modified or unmodified polyol is esterified with acrylic acid, methacrylic acid or mixtures thereof, preferably until there are no residual hydroxyl functionalities. In some embodiments, the additional ethylenically unsaturated compound comprises one of trimethylolpropane triacrylate, glycerol triacrylate, pentaerythritol tetraacrylate, di (trimethylolpropane) tetraacrylate, dipentaerythritol hexaacrylate and (poly) ethoxylated and (poly) propoxylated equivalents thereof, or mixtures thereof.

In some embodiments, the additional 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 additional ethylenically unsaturated compound is a polyurethane (meth) acrylate dispersion.

In some embodiments, the additional ethylenically unsaturated compound is an aqueous compound. The additional ethylenically unsaturated compound may be water-dispersible or water-dilutable. Examples of urethane (meth) acrylate dispersions are7788、/>7655、/>7700、/>7230、7240 and->7177. Examples of suitable water-dilutable urethane (meth) acrylates are, for example +.>6569、/>2002 and->11. Such (meth) propenesAcid ester compounds are well known in the art. Methods for preparing such (meth) acrylate compounds are also known in the art and have been previously described in various patent applications. In some embodiments, the radiation curable polyurethane dispersion and the non-radiation curable additional polyurethane dispersion when present are present in an amount of 100 parts by mass and the additional ethylenically unsaturated compound is present in an amount of 0 to 20 parts by mass, for example 1 to 20 parts by mass.

In some embodiments, the additional olefinically unsaturated compound may comprise at least one of the compounds described for the additional olefinically unsaturated compound, for example a mixture thereof.

In an embodiment of the first aspect, the polyurethane particles are non-radiation curable. The median particle diameter D50 of the polyurethane particles is from 5 to 8. Mu.m. Herein, D50 is the diameter in microns, which separates the diameter distribution into half of the particles above that diameter and half below that diameter. The polyurethane particles of the present invention may alternatively be described as polyurethane beads, polyurethane fillers, or polyurethane microparticles or microspheres. An advantage of an embodiment of the present invention is that the polyurethane particles can provide a soft feel to a coating formed with the composition.

In an embodiment of the first aspect, the Tg (i.e. the glass transition temperature) of the polyurethane particles is at most 0 ℃, preferably at most-40 ℃, more preferably at most-50 ℃. One advantage of embodiments of the present invention is that since polyurethane particles can be glassy at room temperature, they can provide softness to a coating comprising the polyurethane particles. In some embodiments, the polyurethane particles are insoluble, preferably at least insoluble in water. Polyurethane particles are chemically cross-linked polyurethane-based molecules. This distinguishes the particles from aggregates or micelles formed by physical interactions of molecules (e.g. hydrophobic/hydrophilic interactions). In some embodiments, the oil absorption of the polyurethane particles is up to 120%, i.e., 120 grams of oil absorption per 100 grams of polyurethane particles. Herein, the oil absorption is preferably determined using ISO or ASTM techniques, for example using ASTM D281.

In some embodiments, the polyurethane particles have a first volume prior to compression and a second volume of at least 90% of the first volume after compression, e.g., 1 minute, using a force of 63mN and subsequent relaxation, as determined using Micro Compress ion Tes ter-Tes t ing Machines | Shimadzu MCT Ser ies. An advantage of embodiments of the present invention is that the polyurethane particles are soft and resilient. Softness and elasticity can provide a soft feel to a coating comprising the polyurethane particles. The polyurethane particles are solid, i.e., not liquid or gaseous.

The polyurethane particles are generally transparent, but the invention is not limited thereto. In particular embodiments, the polyurethane particles may include dyes or pigments.

In some embodiments, 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 some embodiments, the polyurethane in the polyurethane particles is an aliphatic polyurethane. In some embodiments, the polyurethane particles are formed from a polyol, wherein the polyol preferably comprises at least one of a polyester polyol, a polycarbonate polyol, or a polyether polyol. In a preferred embodiment, the polyurethane particles may 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 process for obtaining polyurethane particles uses a solvent free, preferably free of organic solvents, other than water. An advantage of an embodiment of the present invention is that the polyurethane particles may be free of Volatile Organic Compounds (VOCs), alkylphenol ethoxylates (APEO), phthalates, formaldehyde, and heavy metals. In some embodiments, the polyurethane particles are free of isocyanate groups. Suitable polyurethane particles for use in embodiments of the present invention are, for example, decosphaera HT 8-20、/>850XF and->8FT。

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, a polyol having a molecular weight of at least 500g/mol, iii a compound comprising at least one group reactive with isocyanate groups and at least one hydrophilic group (preferably comprising a salt, or being able to comprise a salt after reaction with a neutralising agent), and iv a compound comprising at least two amino groups selected from primary and secondary amino groups. In some embodiments, compound iv has a molecular weight of up to 200g/mol, e.g. up to 150 g/mol.

In some embodiments, the non-radiation curable additional polyurethane dispersion is prepared by the following method: reacting compound i and compound ii and preferably compound iii, thereby forming a prepolymer; dispersing the prepolymer in an aqueous solvent; and chain extending the prepolymer by reacting the prepolymer with compound iv.

In some embodiments, compound i may be independently selected from any of the compounds described for compound a.

Any polyol known to those skilled in the art may be used as polyol ii. In some embodiments, compound ii may be independently selected from any of the compounds described for compound b. Typical polyols include, but are not limited to, diols and polymeric polyols. In some embodiments, the diols include alkylene diols such as ethylene glycol, 1, 2-and 1.3-propanediol, 1,2-, 1,3-, 1, 4-and 2, 3-butanediol, hexanediol, neopentyl glycol, 1, 6-hexanediol, 1, 8-octanediol, and other diols such as bisphenol-A, cyclohexanediol, cyclohexanedimethanol (1, 4-dimethylolcyclohexane), 2-methyl-1, 3-propanediol, 2, 4-trimethyl-1, 3-pentanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, caprolactone glycol, dimer diols, hydroxylated bisphenols, polyether diols, halogenated diols, and mixtures thereof. However, the present invention is not limited thereto.

In some embodiments, the polymeric polyol for compound ii may be selected from the group consisting of polyester polyols, polyether polyols, polyhydroxy polyester amides, hydroxyl-containing polycaprolactone, 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. Pat. nos. 4,108,814 and 6,576,702, the contents of which are incorporated herein by reference.

In a preferred embodiment, polyol ii comprises a polymeric polyol. Preferred polymeric polyols include polyester polyols, polyether polyols and hydroxy polycarbonates.

Polyester polyols are esterification products prepared by reacting an organic polycarboxylic acid or anhydride thereof with a stoichiometric excess of a diol. In some embodiments, the polyester polyol used as polyol ii may include at least one of polyethylene glycol adipate, polyethylene glycol isophthalate, polyethylene glycol phthalate, polyethylene glycol terephthalate, polycaprolactone polyol, sulfonated polyol, and mixtures thereof. In some embodiments, the polyester polyol may be formed from the diols described for polyol b. Preferred diols for forming the polyester polyols are ethylene glycol, butanediol, hexanediol and neopentyl glycol. Suitable carboxylic acids for preparing the polyester polyols include, but are not limited to, dicarboxylic and tricarboxylic acids and anhydrides, such as maleic acid, maleic anhydride, succinic acid, glutaric anhydride, adipic acid, suberic acid, pimelic acid, azelaic acid, sebacic acid, chlorendic acid, 1,2, 4-butane tricarboxylic acid, phthalic acid, isomers of phthalic acid, phthalic anhydride, fumaric acid, dimer fatty acids, and mixtures thereof. Preferred polycarboxylic acids for forming the polyester polyols include aliphatic or aromatic dibasic acids.

The hydroxyl polyether may be selected from any hydroxyl polyether known in the art. In some embodiments, the hydroxyl poly(s)The ether is obtained by polymerization of epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin, or mixtures thereof. The epoxide may be reacted in a catalyst such as BF ₃ In the presence or absence of a catalyst. The hydroxy polyethers may be formed by adding an epoxide (optionally as a mixture of epoxides) to a component containing reactive hydrogen atoms, such as an alcohol or amine (e.g., water, ethylene glycol, 1, 3-propanediol or 1, 2-propanediol, 4' -dihydroxy-diphenylpropane or aniline).

In some embodiments, the hydroxy polythioether is formed by a thioglycol condensation, which is self-condensing and/or condensation with another diol, dicarboxylic acid, formaldehyde, aminocarboxylic acid, or aminoalcohol. Thus, the hydroxy polythioether can comprise a polythiomixed ether, a polythioether ester, or a polythioether ester amide. However, the hydroxyl polythioether is not limited to these embodiments.

In some embodiments, the hydroxypolyacetals comprise the reaction product of diols (e.g., diethylene glycol, triethylene glycol, 4' -dioxyethoxy-diphenyldimethylmethane, and hexylene glycol) with formaldehyde. In some embodiments, the hydroxypolyacetal is obtained by polymerizing a cyclic acetal. However, the hydroxypolyacetal is not limited to these embodiments.

The hydroxy polycarbonate may be any hydroxy polycarbonate known to those skilled in the art. In some embodiments, the hydroxy polycarbonate is formed by reacting a diol (e.g., 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.

In some embodiments, the hydroxypolyester amides and hydroxypolyamides include predominantly linear (e.g., linear) condensates obtained from the reaction of saturated or unsaturated polycarboxylic acids or anhydrides thereof with multivalent saturated or unsaturated amino alcohols, diamines, polyamines, or mixtures. Among the preferred amino alcohols, diamines and polyamines used to form polyesteramides and polyamides are, but not limited to, 1, 2-diaminoethane, 1, 6-diaminohexane, 2-methyl-1, 5Pentanediamine, 2, 4-trimethyl-1, 6-hexanediamine, 1, 12-diaminododecane, 2-aminoethanol, 2- [ (2-aminoethyl) amino group]Ethanol, piperazine, 2, 5-dimethylpiperazine, 1-amino-3-aminomethyl-3, 5-trimethylcyclohexane (isophoronediamine or IPDA), bis- (4-aminocyclohexyl) -methane, bis- (4-amino-3-methyl-cyclohexyl) -methane, 1, 4-diaminocyclohexane, 1, 2-propylenediamine, hydrazine, urea, amino acid hydrazides, semicarbazide carboxylic acid hydrazides, 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 group ]-N ' - (2-aminoethyl) -piperazine, N- (2-aminoethyl) -N ' - (2-piperazinoethyl) -ethylenediamine, N-bis- (2-aminoethyl)) -N- (2-piperazinoethyl) amine, N-bis- (2-piperazinoethyl) -amine, polyethylenimine, iminodipropylamine, guanidine, melamine, N- (2-aminoethyl) -1, 3-propylenediamine, 3' -diaminobenzidine, 2,4, 6-triaminopyrimidine, polyoxypropylene amine, tetrapropylenepentamine, tripropylenetetramine, N-bis- (6-aminohexyl) amine, N ' -bis- (3-aminopropyl) ethylenediamine, and 2, 4-bis- (4 ' -aminobenzyl) -aniline, and mixtures thereof. Other suitable diamines and polyamines includeD-2000 and D-4000, which are amine-terminated polypropylene glycols differing only in molecular weight (commercially available from Huntsman Chemical Company). Polyhydroxy compounds containing urethane or urea groups may be used. In a specific embodiment, the hydroxypolyamide is a linear polyamide formed by the reaction of adipic acid and 1, 6-diamino-hexane. In one embodiment, the polyesteramide is formed by the reaction of adipic acid, 1, 6-hexanediol, and ethylenediamine.

However, polyol ii is not limited to any of the above examples. For example, polyol ii may be selected from any of the polyols described in the following publications: high Polymers, vol.XVI, "Polyurethanes, chemistry and Technology", saunders-Frisch, interscience Publishers, new York, london, first volume, 1962, pages 32-42 and 44-54, and second volume, 1964, pages 5-6 and 198-199; and Kunststoff-Handbuch, volume VII, vieweg-Hochtlen, carl-Hanser-Verlag, munich, 1966, for example pages 45-71.

In some embodiments, polyol ii comprises two or more compounds described for polyol ii. That is, the polyol compound ii may be a mixture. In a preferred embodiment of the first aspect, the polyol compound ii is a polyester or polyether.

In some embodiments, compound iii may be independently selected from any of the compounds described for compound c.

In some embodiments, compound iv may be independently selected from any of the compounds described for compound f.

In an embodiment of the first aspect, the non-radiation curable further polyurethane dispersion comprises 0.1 to 40wt% of the sum of the mass of the non-radiation curable further polyurethane dispersion, the radiation curable polyurethane dispersion and the polyurethane particles. In some embodiments, the non-radiation curable additional polyurethane dispersion is provided in the form of an aqueous dispersion. Preferably, the aqueous dispersion comprises 30 to 45wt% of a water-dispersible non-radiation-curable further polyurethane. Preferably, the aqueous dispersion has a dynamic viscosity of less than 1000mpa.s, preferably less than 500mpa.s, more preferably less than 200 mpa.s. Preferably, the aqueous dispersion has a pH of 7 to 10. Preferably, the non-radiation curable further polyurethane dispersion has a Tg of 0-100 ℃, e.g. 10-60 ℃. Preferably, the Mw of the water-dispersible non-radiation curable additional polyurethane is at least 100,000g/mol, for example at least 1,000,000g/mol. Examples of commercially available aqueous dispersions which may comprise suitable non-radiation-curable further polyurethane dispersions are 6490、/>6491 and->6493。

In an embodiment of the first aspect, the compound that reacts to obtain the non-radiation curable further polyurethane dispersion further comprises a compound v: diols having a molecular weight of less than 500g/mol, preferably up to 150 g. The diol v may be independently selected from any of the compounds described for compound b, provided that its Mw is lower than or equal to 500g/mol. In an embodiment of the first aspect, the mass ratio of radiation curable polyurethane dispersion to non-radiation curable additional polyurethane dispersion in the composition is at least 1.5.

In an embodiment of the first aspect, the plurality of polyurethane particles comprises 3 to 20wt% of the composition on a solids content basis. In the embodiments described below, the amount of polyurethane particles in terms of solids content 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 embodiments that do not include additional non-radiation curable polyurethane dispersions, the mass ratio of the plurality of polyurethane particles to the radiation curable polyurethane dispersion may be from 0.08 to 1.0. In embodiments comprising a radiation curable further polyurethane dispersion, the mass ratio of the plurality of polyurethane particles to the total amount of radiation curable polyurethane dispersion and radiation curable further polyurethane dispersion compound may be in the range of 0.08 to 1.0.

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

The radiation-curable polyurethane dispersion and the non-radiation-curable polyurethane dispersion may be provided as dispersions in water. That is, the radiation curable polyurethane dispersion may be provided as a radiation curable polyurethane dispersion. The water-dispersible non-radiation-curable polyurethane may be provided as a non-radiation-curable polyurethane dispersion. Preferably, the dispersion comprises 30 to 50wt% polyurethane and the balance water. In these embodiments, preferably, the composition comprises 30 to 85wt% of the radiation curable polyurethane dispersion, 0 to 40wt% of the dispersible additional polyurethane compound, 3 to 20wt% of the polyurethane particles, 0.1 to 5wt% of the photoinitiator, 0.1 to 5wt% of an additive other than the photoinitiator, 0 to 20wt% of additional water in addition to the water contained in the dispersion.

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

In some embodiments, at least one additive is suitable for improving the application of the formulated dispersion to a substrate, such as rheology modifiers, anti-settling agents, wetting agents, leveling agents, anti-cratering agents, defoamers, slip agents, flame retardants, uv protectants, or adhesion promoters. Examples of suitable inhibitors include, but are not limited to, hydroquinone (HQ), methyl hydroquinone (THQ), t-butyl hydroquinone (TBHQ), di-t-butyl hydroquinone (DTBHQ), hydroquinone Monomethyl Ether (MEHQ), 2, 6-di-t-butyl-4-methylphenol (BHT), and the like. Inhibitors may include phosphines such as Triphenylphosphine (TPP) and tris-nonylphenylphosphite (TNPP), phenothiazine (PTZ), triphenylantimony (TPS), and mixtures thereof.

The aqueous radiation curable compositions of embodiments of the present invention are curable by radiation (e.g., by ultraviolet light). Preferably, the irradiation is carried out in the presence of a photoinitiator. Alternatively, the aqueous radiation curable composition may be cured by electron beam irradiation, which may result in good curing in the absence of a photoinitiator. The compositions of embodiments of the present invention can cure at a high rate. The composition may be cured, for example, by UV LED and/or HUV.

In some embodiments, the photoinitiator includes a low to no yellowing photoinitiator, e.g., from IGM1000、/>481 from codex +.>200 +.>73、/>73-w from Chembr bridge +.>481. From IGM->184 and->1173. If the end use of the aqueous radiation curable composition requires low migration and/or for food packaging, it may be preferred to use a polymeric photoinitiator, e.g.from IGM +.>Grade +.>2959 or food-grade thioxanthone photoinitiator. If aqueous radiation curable is consideredFor different end uses of the composition of (a), e.g. inks, it may be preferable to combine the photoinitiator with an amine synergist, e.g +>P 115、/>P116 or->225 are used together. When curing the composition using UV LED curing, it is preferable to use +. >LED 01 or->LED 02。

The radiation curable polyurethane dispersion according to embodiments of the first aspect may comprise at least 1meq/g, typically at least 1.5meq/g, preferably at least 2meq/g of copolymerizable ethylenically unsaturated groups. Here, meq means milliequivalents, and g means grams. Typically the amount is not more than 10meq/g, more preferably not more than 7meq/g, most preferably not more than 5meq/g. That is, the radiation curable polyurethane dispersion may have a degree of unsaturation of from 1 to 10meq double bonds/g of radiation curable polyurethane dispersion, preferably from 1.5 to 7meq double bonds/g of radiation curable polyurethane dispersion, most preferably from 2 to 5meq double bonds/g of radiation curable polyurethane dispersion.

The amount of ethylenically unsaturated groups in the radiation curable polyurethane dispersion can be determined by nuclear magnetic resonance spectroscopy (NMR). The amount of ethylenically unsaturated groups can be expressed in meq/g of solid material. For the determination, dry (i.e., anhydrous and solvent-free) radiation-curable polyurethane samples can be dissolved in N-methylpyrrolidone. Using ¹ H-NMR analysis of the measured samples to determine the molar concentration of olefinically unsaturated groups, wherein, for example, 1,3, 5-bromobenzene may be used as an internal standard. Peaks ascribed to protons bonded to the aromatic ring of the internal standard and peaks ascribed to radiation curable A comparison between peaks of protons of ethylenically unsaturated groups in the polyurethane dispersion may allow the molar concentration of ethylenically unsaturated groups to be calculated. The molar concentration of ethylenically unsaturated groups can be assumed to be proportional to (A.times.B)/C. Where A is the proton ascribed to the ethylenically unsaturated group in the radiation-curable polyurethane dispersion ¹ Integration of the H peak, B is the number of moles of internal standard in the sample, C is measured against the internal standard ¹ Integration of the H peak.

Alternatively, the amount of ethylenically unsaturated groups can be measured by titration after adding an excess of pyridinium sulfate dibromide to the ethylenically unsaturated groups. Here, for example, glacial acetic acid may be used as a solvent, and mercury acetate may be used as a catalyst. The excess releases iodine in the presence of potassium iodide, which is then titrated with sodium thiosulfate.

Generally, the radiation curable polyurethane dispersions of embodiments of the present invention comprise polymeric or oligomeric compounds. In some embodiments, the radiation curable polyurethane dispersions of the present invention have a weight 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 an eluent at 40℃using a 3 XPL 5 μm Mixed-D LS 300X7.5mm column suitable for a Mw range of 162-377400g/mol and calibrated with polystyrene standards.

In some embodiments, the aqueous radiation curable composition of embodiments of the present invention has a total solids content of from 30 to 65wt%, preferably from 35 to 50wt%. Herein, the total solids content includes radiation curable polyurethane dispersion, polyurethane particles, possibly non-radiation curable additional polyurethane dispersion, and possibly solid additives. In some embodiments, the non-solid (e.g., liquid) content of the aqueous radiation curable composition comprises, preferably consists of, water. In some embodiments, the aqueous radiation curable composition has a viscosity of at most 1,000mpa.s, preferably at most 800mpa.s, more preferably at most 500mpa.s, even more preferably at most 200mpa.s, measured at 25 ℃. In some embodiments, the aqueous radiation curable composition has a pH of from 6 to 11, preferably from 6 to 8.5.

The water-dispersible radiation curable polyurethane typically forms nanoparticles when dispersed in water. Typically, the radiation curable polyurethane has an average particle size of at most 200nm, preferably at most 150nm. Typically, the average particle size of the non-radiation curable polyurethane is at most 200nm, preferably at most 150nm.

In some embodiments, the radiation curable polyurethane dispersion has a Tg of from 0 to 100deg.C, such as from 10 to 60deg.C.

Any feature of any embodiment of the first aspect may independently be as described for any embodiment of any other aspect of the invention.

In a second aspect, the present invention relates to a coating formed by curing the composition of the embodiments of the first aspect. In some embodiments, the coating has a thickness in a direction perpendicular to the surface of 2-200 μm. Herein, the thickness is the thickness of a dried coating layer that is generally obtained after removing a liquid including water.

Any feature of any embodiment of the second aspect may independently be as described for any embodiment of any other aspect of the invention.

In a third aspect, the present invention relates to a method of forming a coating of an embodiment of the second aspect, comprising applying the composition of an embodiment of the first aspect to a surface, and curing the composition, thereby forming a coating. In some embodiments, the composition may be applied to a surface in any possible manner, such as by roll coating, spray coating, ink jet, or curtain coating. In some embodiments, the method further comprises the step of drying the coating to remove water and possibly other solvents contained in the composition. In some embodiments, the composition is applied to a surface to form a coating having a thickness in a direction perpendicular to the surface of from 2 to 200 μm. Here, the thickness is the thickness of the dried coating.

In an embodiment of the third aspect, the composition is applied to the surface at a temperature of 40-60 ℃. Subsequently, curing of the composition may be carried out at a temperature of 10-50 ℃, e.g. 20-40 ℃.

Although a specific application of the radiation curable aqueous composition for forming a coating is described, the invention is not limited thereto. Indeed, the radiation curable aqueous compositions of the present invention are useful for forming coatings (transparent and pigmented, glossy or matte), inks, paints, varnishes (e.g., overprint varnishes) and adhesives. The radiation curable aqueous composition may also be used to form composites, gel coats, 3D curing, and the manufacture of general 3D objects (e.g., 3D objects made of polyethylene, polypropylene, polycarbonate, polyvinylchloride, optionally pre-coated with other coatings such as polyurethane).

The invention therefore also relates to the use of the radiation-curable aqueous compositions of embodiments of the invention for the preparation of inks, varnishes (e.g. overprint varnishes), paints, coatings and adhesives, and to a process for the preparation of inks, varnishes (e.g. overprint varnishes), coatings and adhesives, wherein the compositions as described above are used.

In some embodiments, the surface is comprised in a substrate or article. In some embodiments, a coated substrate or article is prepared by an embodiment of the third aspect, wherein 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 may be used in a method of at least partially coating an article or substrate with a coating of an embodiment of the second aspect, comprising:

(a) There is provided a radiation curable aqueous composition,

(b) Applying the composition to the surface of an article or substrate, and

(c) The composition is cured, preferably by irradiating the composition with radiation (e.g., with actinic radiation).

In a subsidiary aspect, the invention relates to an article or substrate at least partially (e.g. fully) coated with a radiation curable aqueous composition of the first aspect of the invention or with a coating of an embodiment of the second aspect of the invention. The substrate may be any substrate, such as wood, metal, paper, plastic, fabric, fiber, ceramic, mineral material (stone, brick), cement, gypsum, glass, leather or leather-like material, concrete, printed or coated material (e.g., melamine board, printing paper, etc.), and the like. The article may be any article, such as a 3D article. Preferably, the article or substrate is made of wood or plastic.

The composition may be applied as a single coating (monocoat) or as a topcoat.

The radiation curable composition is typically a composition that is capable of being cured by a reaction involving free radicals. Although curing is typically carried out by application of radiation, curing may also be carried out, for example, by adding peroxide to the composition. Due to the presence of ethylenically unsaturated functional groups in the radiation curable polyurethane, the radiation curable composition according to embodiments of the first aspect may be cured by exposure to radiation. The ethylenically unsaturated functional groups may be due to the ethylenically unsaturated compounds used to form the radiation curable composition. In a preferred embodiment, the curing of the radiation curable aqueous composition is accomplished by irradiation with UV light (but UV LED light) or Electron Beam (EB). Low energy curing (e.g., UV LED curing) is also possible. That is, the radiation curable aqueous composition may be irradiated with actinic radiation after application to a surface, typically by using UV light or by using an electron beam. A suitable type of radiation for curing the radiation curable composition of the first aspect is UV light. Suitable UV wavelengths are between 200 and 400 nm.

Typical suitable UV light sources emit light having a wavelength between 200-800nm and emit at least some radiation in the range of 200-400 nm.

The UV light source may for example be a UV light emitting diode (UV-LED). UV-LEDs typically emit a spectrum with a strongest wavelength in the range 365-395 nm.

Any feature of any embodiment of the third aspect may independently be as described for any corresponding feature of any embodiment of any other aspect of the invention.

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, electrical appliances, automotive interior and exterior trim, packaging such as cosmetic packaging, furniture, in-mold trim, industrial applications, graphic applications or in-mold labeling, preferably for automotive interior and exterior trim, electrical appliances, consumer electronics or cosmetic packaging.

A particularly preferred use of the coating of embodiments of the present invention is for automotive interior and exterior trim, preferably automotive interior trim.

Any feature of any embodiment of the fourth aspect may independently be as described for any embodiment of any other aspect of the invention.

In a fifth aspect, the present invention relates to a method of forming an aqueous radiation curable composition of an embodiment of the first aspect of the present invention, comprising mixing a radiation curable polyurethane dispersion compound, a plurality of polyurethane particles having a median particle diameter D50 of from 1 to 10 μm, and water, the radiation curable polyurethane dispersion compound being obtained by reacting: a. a compound comprising at least two isocyanate groups, b a polyol having a molecular weight of at least 500g/mol, c a compound comprising at least one group reactive with isocyanate groups and at least one hydrophilic group (preferably comprising a salt, or being able to comprise a salt after reaction with a neutralising agent), d a olefinically unsaturated group compound comprising at least one group reactive with isocyanate groups and at least one olefinically unsaturated group.

The aqueous radiation curable compositions of embodiments of the present invention can be prepared in a variety of ways. The radiation-curable polyurethane dispersions are generally provided in the form of aqueous solutions or dispersions. That is, the water and radiation curable polyurethane dispersion may be provided by a mixture comprising water and radiation curable polyurethane dispersion.

In some embodiments, forming the aqueous radiation curable composition includes a first step of: allowing the compounds a, b, c and d and the compound e, if present, to react. Here, the compounds a, b,c and d may be reacted together simultaneously or in a multistage process. For example, it is possible to react first compound a, compound c and possibly compound b, and second compound d. Optionally, the method further comprises the step of chain extension by reaction with compound f. The step of reacting with compound f is preferably carried out after reacting compounds a, b, c and d and possibly e, wherein compound f reacts with any residual (i.e. unreacted) isocyanate groups. Thus, radiation curable polyurethane dispersions of embodiments of the present invention may be formed, which preferably do not contain unreacted isocyanate groups. Possibly, after termination of the reaction, further olefinically unsaturated compounds may be added. The residual isocyanate content is generally measured by isocyanate titration with an amine. NH (NH) ₂ The amount of groups is generally obtained by calculation. In order to reduce the viscosity of the prepolymer, the reaction can be carried out by adding 5 to 40% by weight, preferably 15 to 25% by weight, of a solvent. Preferably, the solvent is acetone or methyl ethyl ketone.

Subsequently, in embodiments in which the hydrophilic groups provided by compound c do not comprise a salt but are capable of comprising a salt, the radiation curable polyurethane dispersion may be reacted with a neutralizing agent to convert the hydrophilic groups to an anionic salt. 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 (e.g., trimethylamine, triethylamine, triisopropylamine, tributylamine, N-dimethylcyclohexylamine, N-dimethylaniline, N-methylmorpholine, N-methylpiperazine, N-methylpyrrolidine and N-methylpiperidine), low-volatility alcohol amines (e.g., 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 hydroxide, carbonate and bicarbonate). Preferably, the neutralizing agent comprises triethylamine and/or sodium hydroxide. The total amount of these neutralizing agents can be calculated from the total amount of acid groups to be neutralized. In some embodiments, the neutralizing agent is added in a stoichiometric ratio of neutralizing agent to acid groups (e.g., protonated hydrophilic groups) of 0.5:1 to 1:1.

In some embodiments, the radiation curable polyurethane dispersion is dispersed in water, for example by slowly adding the water-dispersible radiation curable polyurethane to the water or conversely by adding the water to the prepolymer. Typically, the dispersing is performed using high shear mixing.

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

Typically, after the prepolymer dispersion is formed, when the dispersion contains a volatile solvent, such as an organic solvent having a boiling point below 100 ℃, the solvent is removed from the dispersion. This can be carried out at reduced pressure relative to atmospheric pressure and at a temperature of 20-90 c, preferably 40-70 c.

In some embodiments, the polyurethane particles are provided in powder form. In some embodiments, the polyurethane particles are provided as a dispersion or suspension. For example, polyurethane particles may be provided in water.

The compositions of embodiments of the present invention may be prepared in a variety of ways. In some embodiments, the radiation curable polyurethane dispersion compound, polyurethane particles, water, and possibly additives and additional compounds are blended and mixed. In some embodiments, high shear mixing is used for mixing. In some embodiments, cowles blades may be used to mix at a speed of preferably 20-2000 revolutions per minute. For example, mixing can be carried out at room temperature under high shear using, for example, cowles blades at a speed of 20 to 2000 revolutions per minute. Here, the rotational speed may depend on the diameter of the Cowles blade, the diameter of the vessel and the volume to be mixed.

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

Any feature of any embodiment of the fifth aspect may independently be as described for any embodiment of any other aspect of the invention.

The 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 mentioned in the examples are parts by weight.

Examples

Radiation-curable polyurethane dispersions and non-radiation-curable polyurethane dispersions

First radiation-curable polyurethane dispersion (UV PUD 1)

UV PUD 1 is a commercial product2804. It is a low migration acrylated urethane translucent dispersion resulting from the reaction of a mixture of compound a, compound b, compound c, compound d, and compound e. The viscosity was 60mPas, the solids content was 34.7wt%, the particle size was 96nm and the pH was 7.2.

Second radiation-curable polyurethane Dispersion (UV PUD 2)

UV PUD 2 is a radiation curable polyurethane dispersion obtained by reacting: 262.1g 4744 (d), 13.4g of neopentyl glycol (e), 118.8g of a polyester of neopentyl glycol with adipic acid and isophthalic acid (Mw 635, b), and 35.1g of dimethylolpropionic acid (c) with 0.3g of dibutyltin dilaurate, 133.9g of isophorone diisocyanate (a) and 66.9g of hexamethylene diisocyanate (a). The prepolymer obtained had a residual NCO of 0.5meq NCO/g. Then 20.7g of triethylamine was added. Finally, 11.8g of ethylenediamine (f) were added after the dispersing step. The final dispersion had a viscosity of 151mPas, a solids content of 35.0wt%, a particle size of 46nm and a pH of 7.9.

Example 1c: non-radiation-curable further polyurethane dispersions

Three dispersions in water containing water-dispersible non-radiation-curable additional polyurethanes were used in the examples: daotan 6490 (PUD 1), daotan 6491 (PUD 2) and Daotan6493 (PUD 3). Each of these dispersions is commercially available. The properties of these dispersions are summarized in table 0 below.

Table 0: performance of PUDs 1, 2 and 3 used in examples

Preparation of aqueous radiation curable compositions and coatings thereof

For the examples, a series of compositions were prepared according to the general formulation described below.

The aqueous radiation curable polyurethane dispersion was poured into a 250mL plastic mixing vessel. Optionally, a non-radiation curable additional polyurethane dispersion is added to the aqueous radiation curable polyurethane aqueous dispersion. The dispersion was stirred using a Cowles mixer blade (5/8') at 600 rpm. Then, water was added to the aqueous dispersion, followed by addition of additives, to obtain a mixture. In an embodiment, add VXW 390 and->VXW 6580 as wetting agent, and +.>500 as a photoinitiator. Finally, a filler (e.g., polyurethane particles or non-polyurethane particles) is added to the mixture. The mixture was stirred at 600rpm for about 20 minutes. All steps were performed at room temperature. Preferably, cowles blades are used to ensure good dispersion of polyurethane particles to obtain the compositions of embodiments of the present invention.

The relative amounts of the different compounds, additives and fillers used in each composition are shown in the examples below.

In the examples below, the composition is used directly after preparation to form a coating. To this end, each composition was applied to a plastic substrate (ABS:3616、ABS/PC：/>t85XF or T65 XF). About 20g/m was obtained using a bar coater ² Dry Film Thickness (DFT). The applied composition was dried at 60 ℃ for 5 minutes. Subsequently, two 120W/cm mercury lamps (1000-1200 mJ/cm ² ) UV radiation curing is performed. The lamp was passed once over the composition at a rate of 15m/min (i.e., about 50 ft/min).

Analytical techniques

The compositions and coatings of the examples were characterized using different analytical techniques, which are described below.

Dynamic Light Scattering (DLS) measurements were used to characterize the hydrodynamic size of particles in different compositions. The concentrated composition was diluted with deionized distilled water prior to DLS measurement. Thus, a particle concentration of 0.05w/w% was obtained. The diluted composition was filtered. Subsequently, DLS measurements were performed at 23℃using a DelsaNano-c particle analyzer of Beckman-Coul ter. The wavelength λ=658 nm of the incident monochromatic light used in DLS measurement. Scattered light was detected at 165 ° angle in the near back scattering geometry. The z-average particle size and polydispersity index are determined by a second order cumulative analysis of the electric field auto-correlation function. The single particle diffusion coefficient is then estimated from the average decay constant. Thus, the median diameter D50 can be obtained by using the stokes relationship.

The solids content was determined gravimetrically. For radiation curable polyurethane dispersions, gravimetric analysis included drying at 120 ℃ for 2 hours. For additional polyurethane dispersions that are not radiation curable, gravimetric analysis included drying at 125 ℃ for 3 hours.

The pH is measured in accordance with DIN EN ISO 10390.

The viscosities of the radiation-curable polyurethane dispersions and of the non-radiation-curable further polyurethane dispersions were measured according to DIN EN ISO 3219 with a cone-plate rheometer MCR092 (Paar-Physicca). At 23℃for 25s ^-1 Is used to control the shear rate.

The coatings were tested for adhesion, softness and DEET resistance.

For the soft feel test, the coatings of the examples were compared with commercially available WB 2k soft feel coatings from General Motors. The softness of the coatings of the examples were rated by three different observers. In the table, each coating was rated using a scale of 1-4, where 1 indicates good soft feel and 4 indicates poor soft feel. Preferably, the coating fraction is 1 or 2.

The resistance of each coating of the examples to DEET and sunscreens, i.e., chemical resistance, was also determined according to the sunscreens and insect repellents resistance test procedure of General purpose Motors, such as GMW 14445. GMW14445 testing was performed at 80 ℃. Other tests were performed at room temperature and ambient humidity. Each coating was rated using a scale of 1-4, where 1 indicates good resistance and 4 indicates poor resistance. Preferably, the coating score is 1.

The adhesion of the coating to the surface of the plastic substrate (ADH) was evaluated using a cross-hatch test. In each case, first, 5 parallel cuts of about 1 cm in length and about 1 mm apart were made in the coating with a knife. Next, 5 parallel cuts of about 1 cm long and spaced about 1 mm apart were made in the transverse direction. Subsequently, the tape is attachedFirmly pressed against the cross-hatched coating and rapidly removed. Damage to the cross-hatched areas of the layer (i.e., due to loss of adhesion) is represented on a scale of 0-5, where 5 = optimal adhesion. Good adhesion is preferred to ensure a strong permanent bond between the coating and the surface.

Coating and composition

According to a preferred embodiment of the invention, the contents (in parts by mass) of a series of compositions and the results of analysis of a series of coatings formed therefrom are summarized in table a. The fillers used are described in tables D, F and H. Each coating summarized in this table has a score of 1 in terms of soft feel properties and chemical resistance (i.e., resistance to sunscreens and DEET).

Coatings and compositions having different concentrations of curable polyurethane and non-curable additional polyurethane

In another example, the effect of the amount of PUD 1 in the composition on the coating properties was tested. The contents (in parts by mass) of a series of compositions and the analytical results of a series of coatings formed therefrom are summarized in table B. Tables D and F describe the fillers used. The last two rows of the table show the wt% of radiation-curable polyurethane and non-radiation-curable polyurethane as a percentage of the total amount of radiation-curable polyurethane and non-radiation-curable polyurethane. It can be observed that for UV PUD 1, the soft feel energy is best when the composition for forming the coating comprises PUD 1. However, preferably, the addition amount of PUD 1 is not too large. For example, the mass ratio of UV PUD 1 to PUD is at least 1.5.

Coatings and compositions with different types of non-radiation curable additional polyurethane compounds

In another example, the effect of the type of PUD in the composition on the coating properties was tested. The analysis results of a series of compositions in parts by mass and a series of coatings formed therefrom are summarized in table C. For each PUD used in the examples, soft feel properties and chemical resistance are both advantageous.

Coatings and compositions using different types of polyurethane particles

In another example, the impact of the characteristics of polyurethane particles on coating properties was tested. Table D summarizes the characteristics of the different polyurethane particles tested. Here, D50 is the median particle diameter (μm). The contents (in parts by mass) of a series of compositions and the analytical results of a series of coatings formed therefrom are summarized in table E. From the examples, it can be seen that, in particular, when the particulate matter is in the range of 1 to 10 μm, the soft feel property is in a preferred range.

Coating and composition with different types of polymethylurea resin particles

In another embodiment, the effect of using different types of particles on the coating properties was tested. Table F summarizes the characteristics of the different particles used in the examples. Here, D50 is the median particle diameter (μm). The contents (in parts by mass) of a series of compositions and the analytical results of a series of coatings formed therefrom are summarized in table G. It can be observed that the results of the polyurethane particles are better than those of the polymethylurea resin particles. The result is also advantageous when a mixture comprising at least polyurethane particles is used.

Coatings and compositions with different types of non-polyurethane particles

The effect of using different types of particles on the coating properties was further tested. Table H summarizes the characteristics of the different particles tested. Here, D50 is the median particle diameter (μm), SC represents the solids content in the form of the filler provided by the manufacturer. The contents (in parts by mass) of a series of compositions and the results of analysis of a series of coatings formed therefrom are summarized in table I. It can be observed that the results for polyurethane particles are better than for other particles, even when the diameter distribution is similar. This clearly demonstrates the advantageous effect of using the polyurethane particles employed in the present invention.

Coatings and compositions using different concentrations of polyurethane particles

In another example, the effect on coating properties of using different amounts of polyurethane particles was tested. The contents (in parts by mass) of a series of compositions and the analytical results of a series of coatings formed therefrom are summarized in table J. For compositions containing more than 20wt% polyurethane particles, the appearance properties and uniformity of the coating are poor. This corresponds to a mass ratio of polyurethane particles to the sum of the non-radiation-curable further polyurethane dispersion and the radiation-curable polyurethane dispersion of more than 1.0. As mentioned in the description of table D, 8FT was provided at 36wt% solids in water. Thus, 10 parts by mass of +.>8FT corresponds to 3.6wt% polyurethane particles in composition F13. Thus, from these examples, the polyurethane particles are present in an amount of 3 to 20 wt% of the compositionThe most advantageous results are obtained when the mass ratio of polyurethane particles to the sum of the water-dispersible non-radiation-curable further polyurethane and the radiation-curable polyurethane dispersion is 0.08 to 1.0.

Table a: test results of coatings formed from different compositions of embodiments of the invention

Table B: test results for coatings formed from different compositions, wherein different concentrations of curable and non-curable additional polyurethane are used>

Table C: test results for coatings formed from different compositions of embodiments of the invention for different non-radiation curable additional polyurethane compounds

Table D: characteristics of polyurethane particles used in the examples of embodiments of the present invention

Watch D (continuous)

	Oil absorption%
		1	70-120
2
		3
4
		5
6	50-75

Table E: test results for coatings formed from different compositions, wherein different types of particles are used

Table F: characteristics of different types of particles used in the examples

Table G: test results for coatings formed from different compositions, wherein different types of particles are used

Table H: characteristics of different types of particles used in the examples

Table I: test results for coatings formed from different compositions, wherein different types of particles are used

Table J: test results for coatings formed from different compositions, wherein different concentrations of polyurethane particles are used

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Claims

1. 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 500g/mol,

c. a compound comprising at least one group reactive with isocyanate groups and at least one hydrophilic group, and

d. an ethylenically unsaturated compound comprising at least one group reactive with isocyanate groups and at least one ethylenically unsaturated group;

a plurality of polyurethane particles which are not radiation-curable and have a median particle diameter D50 of from 1 to 10 μm; and

water.

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

3. The composition of any of the preceding claims, wherein the compound that reacts to obtain the radiation curable polyurethane dispersion further comprises compound e: is a glycol having a molecular weight of up to 400 g/mol.

4. The composition of any of the preceding claims, wherein the compound that reacts to obtain the radiation curable polyurethane dispersion further comprises compound f: a compound comprising at least two amino groups independently selected from primary and secondary amino groups.

5. The composition of any of the preceding claims, wherein the polyol compound b is a polyester or a polycarbonate.

6. The composition of any of the preceding claims, wherein the polyurethane particles have a median particle diameter D50 of 5-8 μιη.

7. The composition according to any of the preceding claims, wherein the composition comprises a further non-radiation curable aqueous polyurethane dispersion obtained by reacting:

i. a compound comprising at least two isocyanate groups,

a polyol having a molecular weight of at least 500g/mol,

a compound comprising at least one group reactive with isocyanate groups and at least one hydrophilic group, and

A compound comprising at least two amino groups selected from primary and secondary amino groups.

8. The composition of claim 7, wherein the non-radiation curable additional polyurethane dispersion comprises 0.1-40wt% of the sum of the mass of the non-radiation curable additional polyurethane dispersion, the radiation curable polyurethane dispersion, and polyurethane particles.

9. The composition of claim 7 or 8, wherein the compound that reacts to obtain the non-radiation curable additional polyurethane dispersion further comprises compound v: is a glycol having a molecular weight of less than 500 g/mol.

10. The composition according to any one of claims 7-9, wherein the polyol compound ii is a polyester or polyether.

11. The composition according to any one of claims 7 to 10 when dependent on claim 8, wherein the mass ratio of radiation curable polyurethane dispersion to non-radiation curable further polyurethane dispersion in the composition is at least 1.5.

12. The composition of any of the preceding claims, wherein the plurality of polyurethane particles comprises 3-20wt% of the composition on a solids content basis.

13. The composition of any of the preceding claims, further comprising at least one of the following additives: catalysts, polymerization inhibitors or photoinitiators.

14. The composition of any of the preceding claims, wherein the polyurethane particles have a Tg of at most 0 ℃.

15. The composition of any of the preceding claims, wherein the polyurethane particles have an oil absorption of at most 120g oil per 100g polyurethane particles.

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

17. A method of forming the coating of claim 16, comprising:

applying the composition of any one of claims 1-15 to a surface, and

curing the composition to form the coating.

18. Use of the coating according to claim 16 for consumer electronics, electrical appliances, automotive interior and exterior trim, packaging, furniture, in-mold decoration, industrial applications, graphic applications or in-mold labeling.

19. A method of forming the aqueous radiation curable composition of any one of claims 1-15, comprising mixing:

a radiation curable polyurethane dispersion compound obtained by reacting:

a. a compound comprising at least two isocyanate groups,

b. a polyol having a molecular weight of at least 500g/mol,

d. an ethylenically unsaturated compound comprising at least one group reactive with isocyanate groups and at least one ethylenically unsaturated group; and

a plurality of polyurethane particles which are not radiation-curable and have a median particle diameter D50 of 1 to 10 μm; and

water.