Active energy ray-curable resin composition, active energy ray-curable emulsion composition, coating composition, laminate, and method for producing the same

Abstract

To provide an active energy ray-curable resin composition excellent in self-emulsifiability in an aqueous medium and excellent in hardness, flexibility and warm water resistance of a coating film formed when the composition is coated on a substrate and cured.SOLUTION: The active energy ray-curable resin composition comprises a urethane (meth)acrylate-based compound (A) which is a reaction product of a polyvalent isocyanate-based compound (a1), a hydroxyl group-containing (meth)acrylate-based compound (a2) and an oxyalkylene group-containing compound (a3) represented by general formula (1) and a glycerol skeleton-containing (meth)acrylate (B). Wherein X represents an alkylene group, Y represents a hydrogen atom, an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n represents an integer of 1 or more. ] SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable resin composition, an active energy ray-curable emulsion composition, a coating composition, a laminate, and a method for producing the same. [Background technology]

[0002] Conventionally, urethane (meth)acrylates obtained by reacting diol compounds such as polyester diols and polyether diols, diisocyanate compounds such as isophorone diisocyanate and diphenylmethane diisocyanate, and hydroxyl group-containing (meth)acrylates such as hydroxyethyl acrylate are known as active energy ray-curable resins and are used in applications such as woodworking paints and plastic coating agents. Such urethane (meth)acrylates generally have high viscosity, so when used, they are diluted with an organic solvent or a reactive diluent to adjust the viscosity before application, and then cured by irradiation with active energy rays such as ultraviolet light to form a coating film. However, dilution with the above organic solvents has become problematic in recent years under VOC regulations regarding air pollution, working environments, fire hazards, etc. On the other hand, dilution with a reactive diluent may require a large amount of the reactive diluent to reduce viscosity, which makes it difficult to obtain sufficient coating film properties. Under these circumstances, there has been an increasing demand in recent years for aqueous systems such as water-dispersible types.

[0003] Patent Document 1 proposes an active energy ray-curable resin composition characterized by containing a urethane (meth)acrylate compound containing an oxyalkylene group and ethylene oxide-modified trimethylolpropane tri(meth)acrylate.

[0004] The technology disclosed in Patent Document 1 has excellent self-emulsifying properties in aqueous media, and when coated on a substrate and cured, a coating film with excellent hardness and hot water resistance is obtained. Even after immersion in hot water, deterioration of the coating film appearance such as whitening and deterioration of adhesion performance are unlikely to occur, making it extremely useful as a coating agent and various other film-forming materials.

[0005] However, it is generally known that the ethylene oxide-modified trimethylolpropane triacrylate used in the examples of Patent Document 1 contains trimethylolpropane triacrylate (TMPTA), which has been pointed out as a possible carcinogen, as a by-product. Recent legal regulations in Europe and the United States have come to require that products not contain even trace amounts of TMPTA, and it is difficult to say that the product complies with such legal regulations.

[0006] Patent Document 2 proposes an active energy ray-curable resin composition containing two or more surfactants, at least one of which has two or more reactive groups. The technology disclosed in Patent Document 2 is an active energy ray-curable resin composition that has high hardness, high solid content, and low viscosity, and has excellent liquid storage stability and freeze-thaw stability at room temperature and high temperatures, and also has excellent water resistance of the coating film.

[0007] However, the technology disclosed in Patent Document 2 uses a reactive surfactant and performs forced emulsification by high-speed stirring with a disper, resulting in a product that contains water, which is disadvantageous in terms of cost when it comes to import, export, or transportation (Patent Document 1 and the present application have excellent self-emulsifying properties, so do not require high-speed stirring equipment like a disper, and can be imported, exported, or transported in a water-free state).

[0008] Furthermore, the technology disclosed in Patent Document 1 does not take into consideration the flexibility of the cured coating film. Furthermore, in recent years, the market has demanded coating agents that not only have hardness but also an excellent balance between low curl and flexibility. Furthermore, in the examples of Patent Document 2, coating film formation is performed under drying conditions of 100°C for 2 minutes, but due to practical equipment constraints and reasons such as reducing damage to plastic substrates, drying conditions of approximately 60 to 80°C are often required. Even when drying at such low temperatures, it is necessary to ensure initial adhesion to the substrate and adhesion after a hot water test. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2017 / 110843 [Patent Document 2] Japanese Patent Publication No. 2022-074123 Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide an active energy ray-curable resin composition, an active energy ray-curable emulsion composition, a coating composition, and a laminate that have excellent self-emulsification properties in an aqueous medium, and that, when coated on a substrate and cured, can form a coating film that is excellent in hardness and flexibility and also has excellent initial adhesion to plastic substrates and adhesion after a hot water test. [Means for solving the problem]

[0011] As a result of extensive research into solving the above-mentioned problems, the present inventors have found that by using a urethane (meth)acrylate compound having an oxyalkylene structure in combination with an ethylenically unsaturated monomer having a specific structure, it is possible to obtain an active energy ray-curable resin composition that has excellent self-emulsification properties in an aqueous medium and that, when coated on a substrate and cured, can give a cured coating film that has high hardness and sufficient flexibility and is resistant to deterioration in coating film appearance such as whitening and deterioration in adhesion performance even after immersion in warm water, and thus completed the present invention.

[0012] The present invention includes the following aspects.

[0013] [1] An active energy ray-curable resin composition comprising a urethane (meth)acrylate compound (A) which is a reaction product of a polyisocyanate compound (a1), a hydroxyl group-containing (meth)acrylate compound (a2), and an oxyalkylene group-containing compound (a3) ​​represented by the following general formula (1), and a glycerin skeleton-containing (meth)acrylate (B): [ka] [In formula (1), X is an alkylene group, Y is a hydrogen atom, an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 1 or greater.] [2] The active energy ray-curable resin composition according to [1], wherein X in the general formula (1) is an ethylene group. [3] The active energy ray-curable resin composition according to [1] or [2], wherein the urethane (meth)acrylate compound (A) is obtained by reacting the polyvalent isocyanate compound (a1) with the hydroxyl group-containing (meth)acrylate compound (a2), followed by reaction with the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1), to form a urethane bond. [4] The active energy ray-curable resin composition according to any one of [1] to [3], wherein the glycerin skeleton-containing (meth)acrylate (B) has a molecular weight of less than 500. [5] The active energy ray-curable resin composition according to any one of [1] to [4], wherein the viscosity of the glycerin skeleton-containing (meth)acrylate (B) at 25°C is less than 200 mPa·s. [6] The active energy ray-curable resin composition according to any one of [1] to [5], wherein the glycerin skeleton-containing polyfunctional (meth)acrylate (B) has an SP value of 9.3 or more and 11.0 or less, as calculated by the Fedors method. [7] The active energy ray-curable resin composition according to any one of [1] to [6], further comprising an ethylenically unsaturated monomer (C) other than the glycerin skeleton-containing polyfunctional (meth)acrylate (B). [8] The active energy ray-curable resin composition according to any one of [1] to [7], wherein the content of the urethane (meth)acrylate compound (A) is 10% by mass or more and 90% by mass or less, based on the total amount of ethylenically unsaturated group-containing compounds contained in the active energy ray-curable resin composition. [9] The active energy ray-curable resin composition according to any one of [1] to [8], further comprising a photopolymerization initiator (D).

[10] An active energy ray-curable emulsion composition comprising the active energy ray-curable resin composition according to any one of [1] to [9] and an aqueous medium.

[11] An adhesive composition comprising the active energy ray-curable resin composition according to any one of [1] to [9].

[12] A coating composition comprising the active energy ray-curable resin composition according to any one of [1] to [9].

[13] A laminate having at least one cured coating film made of the coating composition according to

[12] .

[14] A method for producing the laminate according to

[13] , comprising the steps of applying the coating composition according to

[12] to a substrate and curing the applied coating composition. [Effects of the Invention]

[0014] The active energy ray-curable resin composition of the present invention has excellent self-emulsification properties in an aqueous medium, and when coated on a substrate and cured, a coating film having excellent hardness and flexibility is obtained. Even after immersion in warm water, deterioration of the coating film appearance such as whitening and deterioration of adhesion performance are unlikely to occur. Therefore, the active energy ray-curable resin composition is extremely useful as a variety of coating film-forming materials such as paints, protective coating agents, anchor coating agents, coating agents for hard coats, inks, magnetic powder coating binders, coatings for sandblasting, pressure-sensitive adhesives, adhesives, pressure-sensitive adhesives, printing plates, and in particular as a coating agent for plastic substrates. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described below based on examples of embodiments for carrying out the present invention, but the present invention is not limited to the embodiments described below.

[0016] In this specification, when an expression "X to Y" (X and Y are any numbers) is used, unless otherwise specified, it means "X or more and Y or less," as well as "preferably larger than X" or "preferably smaller than Y." Furthermore, in this specification, when it is expressed as "X or more" (X is any number) or "Y or less" (Y is any number), it also means that "it is preferably greater than X" or "it is preferably less than Y." In this specification, "x and / or y (x and y are optional configurations)" means at least one of x and y, and can mean three possibilities: x only, y only, or x and y. In this specification, "(meth)acrylic" means acrylic and / or methacrylic, "(meth)acryloyl" means acryloyl and / or methacryloyl, and "(meth)acrylate" means acrylate and / or methacrylate. In the present specification, when numerical ranges are described in stages, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. In addition, in the numerical ranges described in this specification, the upper or lower limit of the numerical range can also be replaced with the values ​​shown in the examples.

[0017] Unless otherwise specified, the number average molecular weight referred to herein is the number average molecular weight converted into standard polystyrene molecular weight, and is measured, for example, by a method based on the hydroxyl value measured in accordance with JIS K 1557-1:2007 or by high performance liquid chromatography. In the high performance liquid chromatography, for example, the measurement is performed using a high performance liquid chromatograph (manufactured by Waters, "ACQUITY APC System") with four columns in series: one ACQUITY APC XT450, one ACQUITY APC XT200, and two ACQUITY APC XT45.

[0018] In this specification, unless otherwise specified, the weight-average molecular weight is the weight-average molecular weight converted into standard polystyrene molecular weight, and is measured, for example, using a high-performance liquid chromatograph (manufactured by Waters, "ACQUITY APC System") with four columns in series: one ACQUITY APC XT450, one ACQUITY APC XT200, and two ACQUITY APC XT45.

[0019] In this specification, the term "solid content of an emulsion" refers to the remainder after removing water from the emulsion. The solid content may also be referred to as the non-volatile content.

[0020] <<Active energy ray curable resin composition>> An active energy ray-curable resin composition according to one embodiment of the present invention (hereinafter, may be referred to as "the active energy ray-curable resin composition") contains a urethane (meth)acrylate compound (A) and a glycerin skeleton-containing (meth)acrylate (B).

[0021] Furthermore, the active energy ray-curable resin composition has excellent self-emulsifying properties in an aqueous medium, and becomes an active energy ray-curable emulsion composition by being emulsified in an aqueous medium. In this specification, the term "self-emulsifying" refers to the property of emulsifying by itself upon contact with an aqueous solvent without the need for shearing or the like during emulsification.

[0022] <Urethane (meth)acrylate compound (A)> The urethane (meth)acrylate compound (A) used in the present embodiment is a urethane (meth)acrylate compound comprising a polyisocyanate compound (a1), a hydroxyl group-containing (meth)acrylate compound (a2), and an oxyalkylene group-containing compound (a3) ​​represented by the following general formula (1), and contains, as a representative structure, a urethane (meth)acrylate compound in which an isocyanate group in the polyisocyanate compound (a1) forms a urethane bond with a hydroxyl group in the hydroxyl group-containing (meth)acrylate compound (a2) and a hydroxyl group in the oxyalkylene group-containing compound (a3) ​​represented by the following general formula (1):

[0023] [ka] [In formula (1), X is an alkylene group, Y is a hydrogen atom, an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 1 or greater.]

[0024] The urethane (meth)acrylate compound (A) used in the present embodiment has a hydrophilic structural moiety derived from the oxyalkylene group-containing compound (a3) ​​represented by the above general formula (1), and also has a hydrophobic structural moiety derived from the polyvalent isocyanate compound (a1) and the hydroxyl group-containing (meth)acrylate compound (a2), and therefore functions as a surfactant.

[0025] [Polyisocyanate compound (a1)] As the polyisocyanate compound (a1), various known aromatic, aliphatic or alicyclic polyisocyanates can be used.

[0026] Examples of the polyisocyanate compound (a1) include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate; hydrogenated diphenyl diisocyanates such as methyl hexamethylene diisocyanate, methyl hexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate; Examples of the polyisocyanate include alicyclic polyisocyanates such as dimethylmethane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and 1,4-bis(isocyanatomethyl)cyclohexane; trimer compounds or polymer compounds of these polyisocyanates, allophanate polyisocyanates, biuret polyisocyanates, and water-dispersible polyisocyanates (for example, "AQUANATE 100," "AQUANATE 110," "AQUANATE 200," and "AQUANATE 210," manufactured by Tosoh Corporation). These polyisocyanate compounds (a1) can be used alone or in combination of two or more.

[0027] Among these, aliphatic polyisocyanates and alicyclic polyisocyanates are preferably used in terms of little yellowing of the cured coating film and small shrinkage on cure, and alicyclic polyisocyanates are particularly preferred in terms of the hardness of the cured coating film, and isophorone diisocyanate and 1,3-bis(isocyanatomethyl)cyclohexane are further preferred in terms of self-emulsifying properties.

[0028] [Hydroxyl group-containing (meth)acrylate compound (a2)] Examples of the hydroxyl group-containing (meth)acrylate compound (a2) include monofunctional hydroxyl group-containing (meth)acrylate compounds, difunctional hydroxyl group-containing (meth)acrylate compounds, and trifunctional or higher hydroxyl group-containing (meth)acrylate compounds.

[0029] Examples of monofunctional hydroxyl group-containing (meth)acrylate compounds include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, 2- Examples include primary hydroxyl group-containing (meth)acrylates such as (meth)acryloyloxyethyl-2-hydroxypropyl phthalate; secondary hydroxyl group-containing (meth)acrylates such as 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 2-hydroxyethyl (meth)acryloyl phosphate; and tertiary hydroxyl group-containing (meth)acrylates such as 2,2-dimethyl-2-hydroxyethyl (meth)acrylate.

[0030] Examples of bifunctional hydroxyl group-containing (meth)acrylate compounds include isocyanuric acid ethylene oxide modified di(meth)acrylate, glycerol epichlorohydrin modified 1,6-hexanediol di(meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate.

[0031] Examples of trifunctional or higher hydroxyl group-containing (meth)acrylate compounds include pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified dipentaerythritol penta(meth)acrylate, and ethylene oxide-modified pentaerythritol tri(meth)acrylate.

[0032] These hydroxyl group-containing (meth)acrylate compounds (a2) can be used alone or in combination of two or more.

[0033] Among these, in terms of hardness and water resistance, polyfunctional hydroxyl group-containing (meth)acrylate compounds are preferred, particularly trifunctional or higher hydroxyl group-containing (meth)acrylate compounds are preferred, further preferred are pentaerythritol tri(meth)acrylate and dipentaerythritol penta(meth)acrylate, and particularly preferred is dipentaerythritol penta(meth)acrylate.

[0034] The hydroxyl value of the hydroxyl group-containing (meth)acrylate compound (a2) is preferably 10 to 550 mgKOH / g, more preferably 20 to 300 mgKOH / g, even more preferably 30 to 150 mgKOH / g, and particularly preferably 35 to 120 mgKOH / g. If the hydroxyl value is too low, the hot water resistance of the cured coating film tends to decrease, while if it is too high, the emulsion stability tends to decrease.

[0035] [Oxyalkylene group-containing compound (a3)] The oxyalkylene group-containing compound (a3) ​​is represented by the following general formula (1), and one type can be used alone or two or more types can be used in combination.

[0036] [ka]

[0037] Here, X is an alkylene group, Y is a hydrogen atom, an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 1 or more.

[0038] X in the above general formula (1) is an alkylene group, and among them, an alkylene group having 1 to 10 carbon atoms is preferred in terms of excellent hydrophilicity, and an alkylene group having 1 to 4 carbon atoms such as an ethylene group, a propylene group, or a butylene group is more preferred, and an ethylene group is particularly preferred. When n is a polyoxyalkylene chain moiety of 2 or more, the oxyalkylene group-containing compound (a3) ​​may be a homopolymer of the same oxyalkylene chain, or may be a copolymer of different oxyalkylene chains in a random or block form.

[0039] In the general formula (1), n ​​is an integer of 1 or more, preferably 3 to 300, more preferably 5 to 200, even more preferably 5 to 100, and particularly preferably 6 to 50. If the value of n is too large, the hardness and warm water resistance of the coating film tend to decrease. If the value of n is too small, the self-emulsifying properties tend to decrease.

[0040] Y in the above general formula (1) is any one of a hydrogen atom, an alkyl group, a (meth)acryloyl group, an allyl group, and an acyl group. Among these, a hydrogen atom, an alkyl group, and a (meth)acryloyl group are preferred, and a hydrogen atom is particularly preferred, in terms of the excellent balance between hydrophilicity and reactivity.

[0041] The alkyl group generally has a carbon number of 1 to 20, preferably 1 to 10. Of these, a methyl group and an ethyl group are particularly preferred.

[0042] Examples of the acyl group include an acetyl group, an acetimidoyl group, a thioacetyl group, a benzenesulfonyl group, a phosphononitridoyl group, and a phosphonoyl group, with the acetyl group being preferred among these.

[0043] Specific examples of the oxyalkylene group-containing compound (a3) ​​include the following:

[0044] When Y is a hydrogen atom, examples of the polyol include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyether polyol having at least one structure of block or random copolymerization of ethylene oxide / propylene oxide / butylene oxide, polyoxytetramethylene glycol, polyethylene glycol-polypropylene glycol-polyethylene glycol (block copolymer), polypropylene glycol-polyethylene glycol-polypropylene glycol (block copolymer), polyethylene glycol-polypropylene glycol (random copolymer), polyoxytetramethylene glycol-polyethylene glycol-polyoxytetramethylene glycol (block copolymer), polyoxytetramethylene glycol-polyethylene glycol-polyoxytetramethylene glycol (block copolymer), polyethylene glycol-polyoxytetramethylene glycol (random copolymer), polypropylene glycol-polyoxytetramethylene glycol-polypropylene glycol (block copolymer), polyoxytetramethylene glycol-polypropylene glycol-polyoxytetramethylene glycol (block copolymer), polypropylene glycol-polyoxytetramethylene glycol (random copolymer), polypropylene glycol-polyoxytetramethylene glycol-polypropylene glycol (block copolymer), polyoxytetramethylene glycol-polypropylene glycol-polyoxytetramethylene glycol (block copolymer), polypropylene glycol-polyoxytetramethylene glycol (random copolymer), and the like.

[0045] When Y is an alkyl group, examples thereof include polyethylene glycol derivatives such as polyethylene glycol monomethyl ether, polyethylene glycol lauryl ether, polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol nonylphenyl ether, polyethylene glycol tridecyl ether, polyethylene glycol oleyl ether, polyethylene glycol octylphenyl ether, and polyoxyethylene oleyl cetyl ether; and polypropylene glycol derivatives such as polypropylene glycol monomethyl ether.

[0046] When Y is a (meth)acryloyl group, examples thereof include polyethylene glycol derivatives such as polyethylene glycol mono(meth)acrylate, polypropylene glycol derivatives such as polypropylene glycol mono(meth)acrylate, polyethylene glycol-polypropylene glycol-mono(meth)acrylate, poly(ethylene glycol-tetramethylene glycol) mono(meth)acrylate, poly(propylene glycol-tetramethylene glycol) mono(meth)acrylate, and the like.

[0047] When Y is an allyl group, examples thereof include polyethylene glycol derivatives such as polyethylene glycol monoallyl ether, polypropylene glycol derivatives such as polypropylene glycol monoallyl ether, and polyethylene glycol-polypropylene glycol-monoallyl ether.

[0048] When Y is an acyl group, examples thereof include polyethylene glycol derivatives such as polyethylene glycol monolaurate, polyethylene glycol monostearate, and polyethylene glycol monooleate.

[0049] Among the above, as the oxyalkylene group-containing compound (a3), polyethylene glycol derivatives (compounds in which X in the above general formula (1) is an ethylene group) are preferred, more preferably polyethylene glycol derivatives having an ethylene oxide addition mole number (the value of n in the above general formula (1)) of 5 to 200, even more preferably polyethylene glycol derivatives having an ethylene oxide addition mole number (the value of n in the above general formula (1)) of 5 to 100, and particularly preferably polyethylene glycol derivatives having an ethylene oxide addition mole number (the value of n in the above general formula (1)) of 6 to 50, which are preferred because they have an excellent balance between hydrophilic groups and hydrophobic groups.

[0050] If the number of moles of ethylene oxide added, n, is too small, it tends to be difficult to obtain a stable emulsion, and if it is too large, the hardness and hot water resistance of the cured coating film tends to decrease. Furthermore, in terms of the effect on curability, Y is preferably a hydrogen atom, an alkyl group, or a (meth)acryloyl group, and in terms of self-emulsification, a hydrogen atom is particularly preferred.

[0051] The number average molecular weight of the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1) is preferably 200 to 10,000, more preferably 400 to 5,000, even more preferably 600 to 2,500, and particularly preferably 750 to 1,500. If the weight average molecular weight is too small, it tends to be difficult to obtain a stable emulsion, while if it is too large, the warm water resistance of the cured coating film tends to decrease.

[0052] The weight-average molecular weight of the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1) is preferably 200 to 10,000, more preferably 400 to 5,000, even more preferably 600 to 2,500, and particularly preferably 750 to 1,500. If the weight-average molecular weight is too small, self-emulsification tends to become difficult, whereas if it is too large, the water resistance and hardness of the cured coating film tend to decrease. The weight average molecular weight of the oxyalkylene group-containing compound (a3) ​​represented by the above general formula (1) is calculated from the hydroxyl value.

[0053] Furthermore, the hydroxyl value of the oxyalkylene group-containing compound (a3) ​​represented by the above general formula (1) is preferably 10 to 550 mgKOH / g, more preferably 20 to 300 mgKOH / g, even more preferably 45 to 200 mgKOH / g, and particularly preferably 75 to 150 mgKOH / g. If the hydroxyl value is too low, the hot water resistance of the cured coating film tends to decrease, while if it is too high, the emulsion stability tends to decrease.

[0054] The urethane (meth)acrylate compound (A) used in this embodiment can be obtained by reacting a polyisocyanate compound (a1), a hydroxyl group-containing (meth)acrylate compound (a2), and an oxyalkylene group-containing compound (a3) ​​represented by the above general formula (1) to form a urethane bond.

[0055] Examples of methods for carrying out the reaction to form the urethane bond include: (i) a method in which a polyvalent isocyanate compound (a1), a hydroxyl group-containing (meth)acrylate compound (a2), and an oxyalkylene group-containing compound (a3) ​​represented by the general formula (1) are charged all at once and reacted; (ii) a method in which a polyvalent isocyanate compound (a1) is reacted with a hydroxyl group-containing (meth)acrylate compound (a2), and then an oxyalkylene group-containing compound (a3) ​​represented by the general formula (1); and (iii) a method in which a polyvalent isocyanate compound (a1) is reacted with an oxyalkylene group-containing compound (a3) ​​represented by the general formula (1), and then an hydroxyl group-containing (meth)acrylate compound (a2).

[0056] Among these, from the viewpoint of self-emulsifying properties in aqueous media, the method (ii) above is preferred, in which a hydrophobic polyvalent isocyanate compound (a1) is first reacted with a hydroxyl group-containing (meth)acrylate compound (a2), and then the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1) is reacted therewith, in order to efficiently introduce a hydrophilic structural portion derived from the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1) above into the terminal of the urethane (meth)acrylate compound (A).

[0057] Regarding the proportions of the components (a1) to (a3) ​​when reacting, the proportion of the polyisocyanate compound (a1) is preferably 1 to 80 mass%, more preferably 5 to 40 mass%, and even more preferably 7 to 25 mass%, based on the total of the polyisocyanate compound (a1), the hydroxyl group-containing (meth)acrylate compound (a2), and the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1), the proportion of the hydroxyl group-containing (meth)acrylate compound (a2) is preferably 10 to 95 mass%, more preferably 30 to 90 mass%, and even more preferably 50 to 85 mass%, and the proportion of the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1) is preferably 1 to 80 mass%, more preferably 5 to 60 mass%, and even more preferably 15 to 40 mass%. If the proportions of the components (a1) to (a3) ​​are outside the above ranges, the emulsifiability of the resulting urethane (meth)acrylate compound (A) and the hardness of the cured coating film tend to decrease.

[0058] When reacting the components (a1) to (a3) ​​above, it is preferable to use a catalyst to promote the reaction. Examples of such catalysts include metal catalysts and amine catalysts. Examples of amine catalysts include triethylamine, benzyldiethylamine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene, N,N,N',N'-tetramethyl-1,3-butanediamine, N-ethylmorpholine, etc. Examples of metal salts include zinc-based catalysts such as zinc octenoate, cobalt-based catalysts such as cobalt naphthenate, organic tin-based catalysts such as dibutyltin dilaurate, trimethyltin hydroxide, tetra-n-butyltin, tin octoate, and tin octenoate, and inorganic tin-based catalysts such as stannous chloride and stannic chloride. Other examples include inorganic bismuth compounds such as bismuth nitrate, bismuth bromide, bismuth iodide, and bismuth sulfide; organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate; and organic acid bismuth catalysts such as bismuth 2-ethylhexanoate, bismuth naphthenate, bismuth isodecanoate, bismuth neodecanoate, bismuth laurate, bismuth maleate, bismuth stearate, bismuth oleate, bismuth linoleate, bismuth acetate, bismuth bisneodecanoate, bismuth disalicylate, and bismuth digallate. Among these, amine-based catalysts, tin-based catalysts, and bismuth-based catalysts are preferred, and dibutyltin dilaurate, 1,8-diazabicyclo[5,4,0]undecene, and bismuth 2-ethylhexanoate are more preferred. These may be used alone or in combination of two or more.

[0059] Furthermore, it is preferable to use a polymerization inhibitor in the above reaction.

[0060] As the polymerization inhibitor, any known polymerization inhibitor can be used, including, for example, quinones such as p-benzoquinone, naphthoquinone, toluquinone, and 2,5-diphenyl-p-benzoquinone, and phenols such as hydroquinone, 2,5-di-t-butylhydroquinone, methylhydroquinone, hydroquinone monomethyl ether, mono-t-butylhydroquinone, 2,6-di-t-butylcresol, and pt-butylcatechol. Among these, phenols are preferred, and 2,6-di-t-butylcresol is particularly preferred. These can be used alone or in combination of two or more. The reaction temperature is usually 30 to 90°C, preferably 40 to 80°C, and the reaction time is usually 2 to 10 hours, preferably 3 to 8 hours.

[0061] The weight average molecular weight of the urethane (meth)acrylate compound (A) is preferably 500 or more, more preferably 750 or more, even more preferably 1000 or more, and particularly preferably 2000 or more. The weight average molecular weight of the urethane (meth)acrylate compound (A) is preferably 50000 or less, more preferably 20000 or less, even more preferably 10000 or less, and particularly preferably 5000 or less. That is, it is preferably 500 or more and 50000 or less, more preferably 750 or more and 20000 or less, even more preferably 1000 or more and 10000 or less, and particularly preferably 2000 or more and 5000 or less. If the weight average molecular weight is too small, the cured coating film tends to be brittle and have reduced flexibility, whereas if it is too large, the viscosity becomes high, making it difficult to handle, and the hardness of the cured coating film tends to decrease.

[0062] The number average molecular weight of the urethane (meth)acrylate compound (A) is preferably 300 or more, more preferably 400 or more, even more preferably 500 or more, and particularly preferably 1000 or more. The number average molecular weight of the urethane (meth)acrylate compound (A) is preferably 30000 or less, more preferably 10000 or less, even more preferably 5000 or less, and particularly preferably 3000 or less. If the number average molecular weight is too small, the cured coating film tends to be brittle and have reduced flexibility, whereas if it is too large, the viscosity becomes high, making it difficult to handle, and the hardness of the cured coating film tends to decrease.

[0063] The viscosity of the urethane (meth)acrylate compound (A) is preferably 200 to 20,000 mPa·s, more preferably 350 to 5,000 mPa·s, and even more preferably 500 to 3,000 mPa·s at 60° C. If the viscosity is too high, it tends to be difficult to uniformly disperse the compound in an aqueous medium, whereas if the viscosity is too low, the self-emulsifying ability is low and the solution tends to easily undergo layer separation. The viscosity is measured using an E-type viscometer.

[0064] The content of the urethane (meth)acrylate compound (A) is preferably 10% by mass or more, more preferably 25% by mass or more, even more preferably 35% by mass or more, and particularly preferably 45% by mass or more, based on the total ethylenically unsaturated group-containing compounds contained in the active energy ray-curable resin composition (for example, the total of the urethane (meth)acrylate compound (A) and the glycerin skeleton-containing (meth)acrylate (B), and if an ethylenically unsaturated monomer (C) other than (B) is further contained, the total of (A), (B), and (C)). The upper limit of the content is preferably 90% by mass or less, more preferably 75% by mass or less, even more preferably 65% ​​by mass or less, and particularly preferably 55% by mass or less. That is, the content is preferably 10% by mass or more and 90% by mass or less, more preferably 25% by mass or more and 75% by mass or less, even more preferably 35% by mass or more and 65% by mass or less, and particularly preferably 45% by mass or more and 65% by mass or less. If the content is too low, the stability of the emulsion tends to decrease, whereas if the content is too high, the viscosity becomes high, making it difficult to handle, and the water resistance of the coating film tends to decrease.

[0065] The content of the urethane (meth)acrylate compound (A) is preferably 10% by mass or more and 90% by mass or less, more preferably 25% by mass or more and 75% by mass or less, even more preferably 35% by mass or more and 65% by mass or less, and particularly preferably 45% by mass or more and 55% by mass or less, relative to the active energy ray-curable resin composition. If the content is too low, the stability of the emulsion tends to decrease, while if it is too high, the viscosity becomes high, making it difficult to handle, and the water resistance of the coating film tends to decrease.

[0066] <Glycerin skeleton-containing (meth)acrylate (B)> Examples of the glycerin skeleton-containing (meth)acrylate (B) used in this embodiment include glycerin mono(meth)acrylate, glycerin di(meth)acrylate, glycerin tri(meth)acrylate, ethylene oxide-modified glycerin tri(meth)acrylate, propylene oxide-modified glycerin tri(meth)acrylate, ethylene oxide-modified diglycerin penta(meth)acrylate, and ethylene oxide-modified polyglycerin tri(meth)acrylate. Examples of commercially available products that can be used include lycerin poly(meth)acrylate, such as "Blenmar GLM" manufactured by NOF Corporation, "Aronix M-920," "Aronix M-930," and "Aronix M-460" manufactured by Toagosei Co., Ltd., "SR9020" and "SR9020NS" manufactured by Sartomer, "SA-TE6" and "SA-TE60" manufactured by Sakamoto Pharmaceutical Industry Co., Ltd., and "A-GLY-3E," "A-GLY-9E," and "A-GLY-20E" manufactured by Shin-Nakamura Chemical Co., Ltd.

[0067] Of the above, di- to tetrafunctional acrylates are preferred from the viewpoint of the balance between hardness and flexibility of the cured coating film, and particularly glycerin tri(meth)acrylate, ethylene oxide-modified glycerin tri(meth)acrylate, and propylene oxide-modified glycerin tri(meth)acrylate are preferred, with glycerin tri(meth)acrylate and propylene oxide-modified glycerin tri(meth)acrylate being even more preferred from the viewpoint of water resistance.

[0068] The glycerin skeleton-containing (meth)acrylate (B) has good compatibility with the urethane (meth)acrylate compound (A), and therefore the active energy ray-curable resin composition can be emulsified with fine particle diameters. Furthermore, the glycerin skeleton-containing (meth)acrylate (B) can appropriately increase the particle size when dispersed in water and reduce the viscosity of the aqueous dispersion, which is presumed to improve the coatability of the active energy ray-curable resin composition. Furthermore, since the glycerin skeleton-containing (meth)acrylate (B) does not have a hydrocarbon group in the side chain, it has a higher acryloyl group concentration and superior curability compared to trimethylolpropane triacrylate (TMPTA), which is presumed to improve the hardness of the active energy ray-curable resin composition.

[0069] The molecular weight of the glycerin skeleton-containing (meth)acrylate (B) is preferably less than 1000, more preferably 500 or less, even more preferably 450 or less, and particularly preferably 430 or less. The lower limit is 200 or more. If the molecular weight is too large, the cured coating film tends to become brittle and have reduced flexibility.

[0070] The viscosity of the glycerin skeleton-containing (meth)acrylate (B) at 25° C. is preferably less than 500 mPa·s, more preferably 250 mPa·s or less, and even more preferably 150 mPa·s or less, with the lower limit being 10 mPa·s or more. If the viscosity is too high, it tends to be difficult to disperse uniformly in an aqueous medium, whereas if the viscosity is too low, the self-emulsifying ability is low and the solution tends to undergo layer separation. The viscosity is measured using an E-type viscometer.

[0071] The solubility parameter (SP value) of the glycerin skeleton-containing (meth)acrylate (B) is preferably 9.3 or more, more preferably 9.4 or more, and even more preferably 9.5 or more. The SP value is preferably 11.0 or less, more preferably 10.8 or less, and even more preferably 10.5 or less. That is, it is preferably 9.3 or more and 11.0 or less, more preferably 9.4 or more and 10.8 or less, and even more preferably 9.5 or more and 10.5 or less. When the SP value is equal to or greater than the lower limit, the SP value approaches that of a plastic substrate such as polycarbonate, and initial adhesion tends to be good, whereas when the SP value is equal to or less than the upper limit, the film becomes more hydrophobic and adhesion after a hot water test tends to be good. The solubility parameter (SP value) is a measure of solubility, with a larger SP value indicating higher polarity and a smaller SP value indicating lower polarity. The solubility parameter (SP value) of the glycerin skeleton-containing (meth)acrylate (B) is a value calculated by the method proposed by Fedors et al. Specifically, it can be determined by referring to "POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. (pp. 147-154)."

[0072] The content of the glycerin skeleton-containing (meth)acrylate (B) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, based on the total ethylenically unsaturated group-containing compounds contained in the active energy ray-curable resin composition (e.g., the total of the urethane (meth)acrylate compound (A) and the glycerin skeleton-containing (meth)acrylate (B), and if an ethylenically unsaturated monomer (C) other than (B) is further contained, the total of (A), (B), and (C)). The content is preferably 90% by mass or less, more preferably 75% by mass or less, even more preferably 65% ​​by mass or less, and particularly preferably 55% by mass or less. If the content is too low, the adhesion of the cured coating film after a hot water test tends to decrease, while if the content is too high, the stability of the emulsion tends to decrease.

[0073] The content of the glycerin skeleton-containing (meth)acrylate (B) is preferably 5% by mass or more and 90% by mass or less, more preferably 10% by mass or more and 75% by mass or less, even more preferably 15% by mass or more and 65% by mass or less, and particularly preferably 20% by mass or more and 55% by mass or less, relative to the active energy ray-curable resin composition. If the content is too low, the viscosity becomes high and handling becomes difficult, and the adhesion and water resistance of the coating film tend to decrease, while if the content is too high, the stability of the emulsion tends to decrease and the appearance of the coating film tends to deteriorate.

[0074] <Ethylenically unsaturated monomer (C) other than glycerin skeleton-containing (meth)acrylate (B)> In this embodiment, an ethylenically unsaturated monomer (C) other than the glycerin skeleton-containing (meth)acrylate (B) (hereinafter, may be referred to as "ethylenically unsaturated monomer (C) other than component (B)"). The ethylenically unsaturated monomer (C) may be any monomer having one or more ethylenically unsaturated groups in one molecule, and examples thereof include monofunctional monomers, bifunctional monomers, and trifunctional or higher functional monomers. The ethylenically unsaturated monomers (C) may be used alone or in combination of two or more.

[0075] Examples of the monofunctional monomer include styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl(meth)acrylate, ethyl(meth)acrylate, acrylonitrile, vinyl acetate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, phenoxyethyl(meth)acrylate, 2-phenoxy-2-hydroxypropyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, 3-chloro-2-hydroxypropyl(meth)acrylate, glycerin mono(meth)acrylate, glycidyl(meth)acrylate, lauryl(meth)acrylate, cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, tricyclodecanyl(meth)acrylate, dicyclopentenyl(meth)acrylate, n-butyl(meth)acrylate, hexyl(meth)acrylate, and heptyl(meth)acrylate. Half-esters of phthalic acid derivatives such as acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, n-stearyl (meth)acrylate, benzyl (meth)acrylate, phenol ethylene oxide modified (meth)acrylate, nonylphenol propylene oxide modified (meth)acrylate, 2-(meth)acryloyloxy-2-hydroxypropyl phthalate, etc. Examples of the acrylates include ester (meth)acrylate, furfuryl (meth)acrylate, carbitol (meth)acrylate, benzyl (meth)acrylate, butoxyethyl (meth)acrylate, allyl (meth)acrylate, (meth)acryloylmorpholine, 2-hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, and 2-(meth)acryloyloxyethyl acid phosphate monoester.

[0076] In addition to the above, the monofunctional monomer also includes a Michael adduct of acrylic acid or a 2-(meth)acryloyloxyethyl dicarboxylic acid monoester. Examples of the Michael adduct of acrylic acid include the following. Examples of 2-(meth)acryloyloxyethyl dicarboxylic acid monoesters, which are carboxylic acids having specific substituents, include 2-(meth)acryloyloxyethyl succinic acid monoester, 2-(meth)methacryloyloxyethyl succinic acid monoester, 2-(meth)acryloyloxyethyl phthalic acid monoester, 2-(meth)methacryloyloxyethyl phthalic acid monoester, 2-(meth)acryloyloxyethyl hexahydrophthalic acid monoester, and 2-(meth)methacryloyloxyethyl hexahydrophthalic acid monoester. Oligoester (meth)acrylates are also included.

[0077] Examples of the bifunctional monomer include (meth)acrylic acid dimer, 2-(meth)acryloyloxyethyl dicarboxylic acid monoester, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, Examples of the di(meth)acrylate include aryl A-type di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,6-hexanediol ethylene oxide-modified di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalic acid diglycidyl ester di(meth)acrylate, hydroxypivalic acid-modified neopentyl glycol di(meth)acrylate, isocyanuric acid ethylene oxide-modified diacrylate, 2-(meth)acryloyloxyethyl acid phosphate diester, and ethylene oxide-modified isocyanuric acid di(meth)acrylate.

[0078] Examples of the tri- or higher functional monomers include (meth)acrylic acid trimer, (meth)acrylic acid tetramer, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, isocyanuric acid ethylene oxide modified triacrylate, ethylene oxide modified dipentaerythritol penta(meth)acrylate, (meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tetra(meth)acrylate, succinic acid-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, ethylene oxide-modified isocyanuric acid tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, and the like.

[0079] In the present invention, ethylenically unsaturated monomers having water-solubility or water-dispersibility may be used in view of emulsion stability and compatibility with the resin. Examples of the water-soluble or water-dispersible ethylenically unsaturated monomer include acryloylmorpholine, polyethylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethylene oxide-modified pentaerythritol tetraacrylate, ethylene oxide-modified isocyanuric acid diacrylate, ethylene oxide-modified isocyanuric acid triacrylate, ethylene oxide-modified epoxy acrylate, polyester acrylate containing polyethylene glycol as the main component, etc. Among these, acryloylmorpholine, polyethylene glycol diacrylate, ethylene oxide-modified isocyanuric acid diacrylate, ethylene oxide-modified isocyanuric acid triacrylate, etc. are preferred.

[0080] When an ethylenically unsaturated monomer (C) other than component (B) is contained, it is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, based on the total amount of ethylenically unsaturated group-containing compounds contained in the active energy ray-curable resin composition (e.g., the total of (A), (B), and (C)). The content is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less. That is, it is preferably 5% by mass or more to 60% by mass or less, more preferably 10% by mass or more to 50% by mass or less, even more preferably 15% by mass or more to 40% by mass or less, and particularly preferably 20% by mass or more to 30% by mass or more. If the content is too low, the adhesion of the cured coating film after a hot water test tends to decrease, while if the content is too high, the stability of the emulsion tends to decrease.

[0081] The content of the ethylenically unsaturated monomer (C) other than component (B) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, based on the active energy ray-curable resin composition. The content is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less. That is, the content is preferably 5% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 50% by mass or less, even more preferably 15% by mass or more and 40% by mass or less, and particularly preferably 20% by mass or more and 30% by mass or more. If the content is too low, the adhesion of the cured coating film after a hot water test tends to decrease, while if the content is too high, the stability of the emulsion tends to decrease.

[0082] <Photopolymerization initiator (D)> The active energy ray-curable resin composition preferably contains a photopolymerization initiator (D) that initiates polymerization upon irradiation with active energy rays, in order to promote curing upon irradiation with active energy rays. The photopolymerization initiator (D) may be used alone or in combination of two or more.

[0083] The photopolymerization initiator (D) is not particularly limited as long as it generates radicals by the action of light.

[0084] Examples of the photopolymerization initiator (D) include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 1-(4-isopropylenephenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyphenyl)-2-methyl ...2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-methylprop (hydroxyethoxy)-phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzil dimethyl ketal, benzophenone , 4-methylbenzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, camphorquinone, dibenzosuberone, 2-ethylanthraquinone, 4',4''-diethylisobenzophenone Examples of photopolymerization initiators include phthalophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, α-acyloxime ester, acylphosphine oxide, methylphenyl glyoxylate, 9,10-phenanthrenequinone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. As the photopolymerization initiator (D), it is preferable to use at least one selected from the group consisting of these photopolymerization initiators.

[0085] Among these, as the photopolymerization initiator (D), it is more preferable to use at least one selected from the group consisting of benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzoin isopropyl ether, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and it is even more preferable to use at least one selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0086] The photopolymerization initiator (D) may be a commercially available product. Examples of such commercially available photopolymerization initiators include Omnirad 184 (1-hydroxycyclohexyl phenyl ketone, manufactured by IGM Resins), Omnirad 500 (1-hydroxycyclohexyl phenyl ketone, manufactured by IGM Resins), Omnirad 1173 (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by IGM Resins), Omnirad 907 (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, manufactured by IGM Resins), and Omnirad TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by IGM Resins). Omnirad is a registered trademark of IGM Group BV in Japan.

[0087] As the photoinitiator (D), it is preferable to use a water-soluble or water-dispersible photoinitiator in order to further maximize the functionality of the composition in use as an aqueous dispersion. Examples of such water-soluble or water-dispersible photoinitiators include 2-(3-dimethylamino-2-hydroxypropoxy)-3,4-dimethyl-9H-thioxanthone-9-one methchloride (Quantacure QTX, manufactured by Octel Chemicals) and 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (Omnirad 2959, manufactured by IGM Resins). These may be used alone or in combination. Among these, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (Omnirad 2959, manufactured by IGM Resins) is preferred.

[0088] The amount of photopolymerization initiator (D) used is preferably 1 part by mass or more, more preferably 2 parts by mass or more, per 100 parts by mass of the total of components (A), (B), and (D) (or the total of components (A), (B), (C), and (D) when component (C) is included). When the amount of photopolymerization initiator (D) used is equal to or greater than the lower limit, the curing rate upon irradiation with active energy rays such as ultraviolet rays is sufficiently fast, making it easier to obtain the desired cured coating film. The amount of photopolymerization initiator (D) used is preferably 20 parts by mass or less, more preferably 16 parts by mass or less, and particularly preferably 10 parts by mass or less. Even if the amount of photopolymerization initiator (D) used exceeds the upper limit, the curability is not improved. However, by keeping the amount equal to or less than the upper limit, the cured coating film is less likely to yellow. The lower and upper limits of the amount of photopolymerization initiator (D) used can be arbitrarily combined, and for example, 1 to 20 parts by mass is preferred, 1 to 16 parts by mass is more preferred, and 2 to 10 parts by mass is particularly preferred.

[0089] <Optional ingredients> The active energy ray-curable resin composition may further contain optional components other than the urethane (meth)acrylate compound (A), the glycerin skeleton-containing (meth)acrylate (B), the ethylenically unsaturated monomer (C) other than component (B), and the photopolymerization initiator (D) that can be used as appropriate, within the range that does not impair the effects of the present invention (10% by mass or less based on the active energy ray-curable resin composition).

[0090] Examples of the optional component include a surface conditioner (leveling agent), a UV absorber, an organic filler, an inorganic filler, a dye or pigment, an oil, a plasticizer, a wax, a drying agent, a dispersant, a wetting agent, a gelling agent, a stabilizer, an antifoaming agent, a thixotropy-imparting agent, an antioxidant, a tackifying agent, a flame retardant, an antistatic agent, a filler, a reinforcing agent, a matting agent, a crosslinking agent, silica, water-dispersed silica, an antiseptic, an antifungal agent, a freeze-thaw stabilizer (e.g., ethylene glycol), a film-forming agent (e.g., butyl cellosolve), and a polar solvent for aiding water dispersion (e.g., N-methylpyrrolidone, 3-methoxy-N,N-dimethylpropionamide).

[0091] The present active energy ray-curable resin composition has excellent self-emulsification properties in an aqueous medium due to the combined use of a urethane (meth)acrylate compound (A) containing an oxyalkylene group-containing compound represented by the following formula (1) and a glycerin skeleton-containing (meth)acrylate (B). Therefore, the composition can be dispersed in an aqueous solvent, and by dispersing the present active energy ray-curable resin composition in an aqueous solvent, an active energy ray-curable emulsion composition (hereinafter, sometimes referred to as the present active energy ray-curable emulsion composition) can be obtained.

[0092] [ka] [In formula (1), X is an alkylene group, Y is a hydrogen atom, an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 1 or greater.]

[0093] The active energy ray-curable emulsion composition will now be described.

[0094] <<Activated energy ray curable emulsion composition>> The active energy ray-curable emulsion composition includes the active energy ray-curable resin composition described above. That is, the active energy ray-curable emulsion composition is an emulsion composition in which the active energy ray-curable resin composition is emulsified in an aqueous medium.

[0095] The active energy ray-curable emulsion composition preferably contains water as an aqueous solvent. The aqueous solvent is not limited to water, and may be a solvent obtained by mixing water with a lower alcohol having 1 to 5 carbon atoms, as long as the emulsion state is not impaired.

[0096] The content of the active energy ray-curable resin composition in the active energy ray-curable emulsion composition is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. Furthermore, the content is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. That is, the content is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 30% by mass or more and 70% by mass or less.

[0097] The amount of aqueous solvent used is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to the total mass (100% by mass) of the active energy ray-curable emulsion composition. If the amount of aqueous solvent used is equal to or greater than the lower limit, phase inversion is likely to occur, and the viscosity is likely to be sufficiently low. The amount of aqueous solvent used is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. If the amount of aqueous solvent used is equal to or less than the upper limit, the drying load during coating is reduced. The lower and upper limits of the amount of aqueous solvent used can be arbitrarily combined, and for example, 5 to 80% by mass is preferred, 10 to 70% by mass is more preferred, and 20 to 60% by mass is more preferred.

[0098] The solids concentration of the active energy ray-curable emulsion composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, based on 100% by mass of the total mass of the active energy ray-curable emulsion composition. When the solids concentration is at least the lower limit, unevenness on the substrate is less likely to occur during coating, and the drying load is reduced. The solids concentration is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. When the solids concentration is at most the upper limit, fluidity is improved, making coating easier. The lower and upper limits of the solids concentration can be arbitrarily combined; for example, a range of 5 to 80% by mass is preferred from the viewpoint of coating workability, more preferably 10 to 70% by mass, and even more preferably 20 to 60% by mass.

[0099] The volume average particle diameter of the active energy ray-curable emulsion composition is preferably 35 nm or more, more preferably 50 nm or more, even more preferably 60 nm or more, and even more preferably 70 nm or more. When the volume average particle diameter is equal to or greater than the lower limit, the emulsion viscosity is sufficiently reduced, resulting in superior handleability. The volume average particle diameter is preferably 300 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, and even more preferably 130 nm or less. When the volume average particle diameter is equal to or less than the upper limit, aggregation is less likely to occur, resulting in improved emulsion stability. The lower and upper limits of the volume average particle diameter can be arbitrarily combined; for example, 35 to 190 nm is preferred, 50 to 200 nm is more preferred, 60 to 150 nm is even more preferred, and 70 to 130 nm is even more preferred. The volume-average particle size refers to the average value of the scattering intensity distribution on a volume basis, and is measured using a laser scattering / diffraction device (LA950V2, manufactured by Horiba, Ltd.).

[0100] The viscosity of the active energy ray-curable emulsion composition at 25°C is not particularly limited, but is preferably 5 mPa·s or more, more preferably 10 mPa·s or more, even more preferably 20 mPa·s or more, and even more preferably 30 mPa·s or more. When the viscosity is at least the lower limit, film thickness control becomes easier. The viscosity is preferably 10,000 mPa·s or less, more preferably 5,000 mPa·s or less, even more preferably 2,500 mPa·s or less, and even more preferably 1,200 mPa·s or less. When the viscosity is at most the upper limit, handling becomes easier and coating workability improves. The lower and upper limits of the viscosity can be arbitrarily combined; for example, 5 to 10,000 mPa·s is preferred, 10 to 5,000 mPa·s is more preferred, 20 to 2,500 mPa·s is more preferred, and 30 to 1,200 mPa·s is even more preferred. The viscosity is measured using an E-type viscometer (100 rpm).

[0101] The active energy ray-curable emulsion composition may contain an aqueous dispersion or solution of an acrylic emulsion, polyurethane dispersion, or the like, which is different from the active energy ray-curable resin composition.

[0102] (Method for producing active energy ray-curable emulsion composition) Next, a method for producing the active energy ray-curable emulsion composition will be described.

[0103] The active energy ray-curable emulsion composition may be, for example, (1) A method in which a urethane (meth)acrylate compound (A), a glycerin skeleton-containing (meth)acrylate (B), and an aqueous solvent are charged all at once and stirred usually at 30 to 80°C, preferably 45 to 65°C; (2) A method in which an aqueous solvent is added dropwise to a urethane (meth)acrylate compound (A) and a glycerin skeleton-containing (meth)acrylate (B) while stirring them usually at 30 to 80°C, preferably 45 to 65°C; (3) A method in which the urethane (meth)acrylate compound (A) and the glycerin skeleton-containing (meth)acrylate (B) are added dropwise to an aqueous solvent while stirring the aqueous solvent at a temperature of usually 30 to 80°C, preferably 45 to 65°C; etc.

[0104] Among these, method (2) is preferred because it can produce a uniform emulsion.

[0105] When a photopolymerization initiator (D), an ethylenically unsaturated monomer (C) other than component (B), and other components are added, the urethane (meth)acrylate compound (A) and the glycerin skeleton-containing (meth)acrylate (B) may be mixed together in advance and then emulsified by stirring. Alternatively, the urethane (meth)acrylate compound (A), the glycerin skeleton-containing (meth)acrylate (B), and an aqueous solvent may be emulsified, and then the photopolymerization initiator (D), the ethylenically unsaturated monomer (C) other than component (B), and other components may be added. However, the method for adding the photopolymerization initiator (D), the ethylenically unsaturated monomer (C) other than component (B), and other components is not limited to these methods.

[0106] The active energy ray-curable emulsion composition can maintain a uniformly dispersed state without precipitation even after being left standing at room temperature (23°C) for 1 to 2 months, for example, in an emulsion composition having a concentration of 50% by mass.

[0107] [Coating compositions and laminates] The active energy ray-curable emulsion composition can be used as a curable resin composition (coating composition) for forming a coating film on various substrates, and is useful as a top coating agent or anchor coating agent for various substrates. For example, an active energy ray-curable emulsion composition can be coated on a substrate, dried, and then irradiated with active energy rays to cure the coating, thereby forming a cured coating on the substrate.

[0108] Furthermore, when the active energy ray-curable resin composition of the present invention is used as a coating composition, a laminate having at least one cured coating film made of the coating composition can be produced. The laminate may have layers other than the layer formed from the active energy ray-curable resin composition of the present invention.

[0109] Examples of the coating method include wet coating methods such as spraying, showering, dipping, rolling, spinning, and screen printing.

[0110] The drying temperature can usually be set to 40 to 120° C., and preferably 50 to 100° C. When a plastic substrate is used, a drying temperature of about 60 to 80° C. is often used from the viewpoint of balancing drying properties and reducing damage to the substrate.

[0111] The drying time can be from 1 to 20 minutes, and is preferably from 2 to 15 minutes.

[0112] Examples of active energy rays include light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, electromagnetic waves such as X-rays and gamma rays, as well as electron beams, proton beams, and neutron beams. Among these, ultraviolet radiation is preferred in terms of curing speed, ease of availability of radiation equipment, cost, etc. When electron beam radiation is used, curing can be achieved without using a photopolymerization initiator (D).

[0113] The method of curing by ultraviolet irradiation uses, for example, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an LED lamp, or the like, which emits light in the wavelength range of 150 to 450 nm, and typically has an intensity of 100 to 3000 mJ / cm. 2 After the ultraviolet irradiation, heating may be carried out as necessary to ensure the curing.

[0114] Examples of substrates to which the active energy ray-curable emulsion composition can be applied include polyolefin resins such as polyethylene, polypropylene, and polycyclopentadiene, polycarbonate, polyester, ABS resin, and acrylic resin, as well as molded products thereof (films, sheets, cups, etc.), metals, and glass.

[0115] When a coating film is formed using the active energy ray-curable emulsion composition under the conditions described below, the cured coating film can have the following physical properties.

[0116] (Coating film formation conditions) The active energy ray-curable emulsion composition was applied to the surface of a 125 μm thick, highly adhesive polyethylene terephthalate film using a bar coater, dried at 70°C for 5 minutes, and then exposed to a high-pressure mercury lamp with an integrated light intensity of 450 mJ / cm. 2 The coating is cured by irradiating it with ultraviolet light to form a coating film with a thickness of 10 μm. The term "highly adhesive polyethylene terephthalate film" refers to a polyethylene terephthalate film whose one or both sides have been surface-modified with a primer such as an aqueous urethane resin, an aqueous polyester resin, or an aqueous acrylic resin. Examples of such products include COSMOSHINE A4300 and COSMOSHINE A4360 manufactured by Toyobo Co., Ltd.

[0117] The pencil hardness of the cured coating film is preferably at least F, more preferably at least H, and even more preferably at least 2H. When the pencil hardness of the coating film is at least the lower limit, it is highly useful for various applications such as protective coating agents and hard coat coating agents. The pencil hardness is measured under a load of 750 g in accordance with the method of JIS K 5600-5-4; 1999 using a coating film formed under the following coating film forming conditions.

[0118] The flexibility of the cured coating film is measured by the maximum diameter at which cracks or peeling occur using a cylindrical mandrel bending tester in accordance with the method of JIS K 5600-5-1: 1999 for a coating film formed under the above coating film formation conditions, and is preferably 16 mm or less, more preferably 13 mm or less, and even more preferably 10 mm or less, with the lower limit usually being 1 mm.

[0119] The transparency of the cured coating film can be determined by measuring the total light transmittance (%) and haze value (%) using a haze meter (NDH 4000, manufactured by Nippon Denshoku Industries Co., Ltd.). The total light transmittance (%) is preferably 80% or higher, more preferably 85% or higher, and even more preferably 90% or higher. The upper limit is usually 100%. The haze value is preferably 1.0% or lower, preferably 0.9% or lower, and even more preferably 0.8% or lower. The lower limit is usually 0.1%.

[0120] The yellowing of the cured coating film can be measured by measuring the b* value using a color difference meter (SE 6000, manufactured by Nippon Denshoku Industries Co., Ltd.). * The value is preferably 1.0% or less, more preferably 0.8% or less, and even more preferably 0.7% or less. The lower limit is usually 0.1%.

[0121] The active energy ray-curable emulsion composition described above, when coated on a substrate and cured, gives a coating film that is excellent in hardness and flexibility, and is resistant to deterioration in coating film appearance such as whitening and deterioration in adhesion performance even after immersion in warm water. Therefore, the composition is very useful as a variety of coating film-forming materials, such as paints, pressure-sensitive adhesives, adhesives, tacky adhesives, inks, protective coating agents, anchor coating agents, coating agents for hard coats, magnetic powder coating binders, coatings for sandblasting, printing plates, coating agents for optical film top coats, metal vapor deposition and sputtering films, and coating agents for glass modification. [Example]

[0122] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. In the examples, "parts" and "%" are based on mass.

[0123] First, the following ingredients were prepared:

[0124] [Urethane (meth)acrylate compound (A)] Preparation of urethane (meth)acrylate compound (A-1) A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 96.1 g (0.432 mol) of isophorone diisocyanate, 606 g (0.519 mol) of an acrylic acid adduct of dipentaerythritol [hydroxyl value: 48.0 mg KOH / g], 1.65 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and the mixture was reacted at 70°C. When the residual isocyanate groups reached 2.1% or less, the mixture was cooled to 60°C, and 298 g (0.302 mol) of polyethylene glycol (hydroxyl value: 114.0 mg KOH / g, weight-average molecular weight calculated from the hydroxyl value: 984) was added and reacted at 60°C. The reaction was terminated when the residual isocyanate groups reached 0.1% or less, yielding a composition containing urethane acrylate (A-1) (resin concentration: 100%, weight-average molecular weight: 3500, number-average molecular weight: 1500, viscosity at 60°C: 1200 mPa s).

[0125] Preparation of urethane (meth)acrylate compound (A-2) A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 104 g (0.469 mol) of isophorone diisocyanate, 504 g (0.422 mol) of an acrylic acid adduct of dipentaerythritol [hydroxyl value: 47.0 mg KOH / g], 69.4 g (0.141 mol) of an acrylic acid adduct of pentaerythritol [hydroxyl value: 114 mg KOH / g], 1.65 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and the mixture was reacted at 70°C. When the residual isocyanate groups reached 2.3% or less, the mixture was cooled to 60°C, and 323 g (0.328 mol) of polyethylene glycol (hydroxyl value: 114 mg KOH / g, weight-average molecular weight calculated from the hydroxyl value: 984) was added and reacted at 60°C. The reaction was terminated when the residual isocyanate groups reached 0.1% or less, yielding a composition containing urethane acrylate (A-2) (resin concentration: 100%, weight-average molecular weight: 3400, number-average molecular weight: 1500, viscosity at 60°C: 1200 mPa s).

[0126] Preparation of urethane (meth)acrylate compound (A-3) A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 116 g (0.520 mol) of isophorone diisocyanate, 372 g (0.312 mol) of an acrylic acid adduct of dipentaerythritol [hydroxyl value: 47.0 mg KOH / g], 154 g (0.312 mol) of an acrylic acid adduct of pentaerythritol [hydroxyl value: 114 mg KOH / g], 1.65 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and the mixture was reacted at 70°C. When the residual isocyanate groups reached 2.7% or less, the mixture was cooled to 60°C, and 358 g (0.364 mol) of polyethylene glycol (hydroxyl value: 114 mg KOH / g, weight-average molecular weight calculated from the hydroxyl value: 984) was added and reacted at 60°C. The reaction was terminated when the residual isocyanate groups reached 0.1% or less, yielding a composition containing urethane acrylate (A-3) (resin concentration: 100%, weight-average molecular weight: 3300, number-average molecular weight: 1500, viscosity at 60°C: 1000 mPa s).

[0127] Preparation of urethane (meth)acrylate compound (A-4) A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 94.0 g (0.423 mol) of isophorone diisocyanate, 559 g (0.508 mol) of an acrylic acid adduct of dipentaerythritol [hydroxyl value: 51.0 mg KOH / g], 1.65 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and the mixture was reacted at 70°C. When the residual isocyanate groups reached 2.2% or less, the mixture was cooled to 60°C, and 347 g (0.351 mol) of polyethylene glycol monomethyl ether (hydroxyl value: 56.7 mg KOH / g, weight-average molecular weight calculated from the hydroxyl value: 990) was added and reacted at 60°C. The reaction was terminated when the residual isocyanate groups reached 0.1% or less, yielding a composition containing urethane acrylate (A-4) (resin concentration: 100%, weight-average molecular weight: 2700, number-average molecular weight: 1500, viscosity at 60°C: 550 mPa s).

[0128] [Glycerin skeleton-containing (meth)acrylate (B)] Glycerin skeleton-containing (meth)acrylate (B-1): A mixture of glycerin triacrylate and glycerin diacrylate (molecular weight: 268.3, viscosity at 25°C: 30 mPa·s, SP value: 10.4) (Aronix M-930; manufactured by Toagosei Co., Ltd.) Glycerin skeleton-containing (meth)acrylate (B-2): Propylene oxide-modified glycerin triacrylate (molecular weight: 428.5, viscosity at 25°C: 95 mPa·s, SP value: 9.6) (SR9020NS; manufactured by Sartomer Corporation)

[0129] [Ethylenically unsaturated monomer (C) other than component (B)] Ethylenically unsaturated monomer (C-1): Ethylene oxide-modified pentaerythritol tetraacrylate (molecular weight: 572.6, viscosity at 25°C: 120-200 mPa·s, SP value: 10.0) (Miramar M4004; manufactured by MIWON Co., Ltd.) Ethylenically unsaturated monomer (C-2): caprolactone 2-mol-modified dipentaerythritol hexaacrylate (molecular weight: 806.8, viscosity at 25°C: 1500-3000 mPa·s, SP value: 10.3) (KAYARAD DPCA-20; manufactured by Nippon Kayaku Co., Ltd.) Ethylenically unsaturated monomer (C-3): caprolactone 3-mol-modified dipentaerythritol hexaacrylate (molecular weight: 921.0, viscosity at 25°C: 1000-2000 mPa·s, SP value: 10.3) (KAYARAD DPCA-30; manufactured by Nippon Kayaku Co., Ltd.) Ethylenically unsaturated monomer (C-4): 12-mol-caprolactone-modified dipentaerythritol hexaacrylate (molecular weight: 1936.3, viscosity at 25°C: 1000 to 2700 mPa·s, SP value: 10.2) (KAYARAD DPCA-120; manufactured by Nippon Kayaku Co., Ltd.) Ethylenically unsaturated monomer (C-5): a mixture of ethylene oxide-modified isocyanuric acid diacrylate and ethylene oxide-modified isocyanuric acid triacrylate (molecular weight: 369.3, viscosity at 25°C: 20,000 to 36,000 mPa·s, SP value: 12.6) (Aronix M-313; manufactured by Toagosei Co., Ltd.) Ethylenically unsaturated monomer (C-6): A mixture of ethylene oxide-modified isocyanuric acid diacrylate and ethylene oxide-modified isocyanuric acid triacrylate (molecular weight: 423.4, viscosity at 25°C: solid at room temperature, SP value: 12.3) (Aronix M-315; manufactured by Toagosei Co., Ltd.) Ethylenically unsaturated monomer (C-7): propylene oxide 6 mol modified trimethylolpropane triacrylate (molecular weight: 644.8, viscosity at 25°C: 70 to 170 mPa·s, SP value: 9.2) (Aronix M-321; manufactured by Toagosei Co., Ltd.) Ethylenically unsaturated monomer (C-8): acrylic acid adduct of pentaerythritol (molecular weight: 317, viscosity at 25°C: 400-700 mPa·s, SP value: 10.8) (Viscoat #300; manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0130] [Photopolymerization initiator (D)] Photopolymerization initiator (D-1): 1-hydroxycyclohexyl phenyl ketone (OMNIRAD500 manufactured by IGM Resins) Photopolymerization initiator (D-2): 1-hydroxycyclohexyl phenyl ketone (OMNIRAD184, manufactured by IGM Resins)

[0131] [others] Leveling agent: Evonik Degussa TEGOWET270 Acrylic emulsion Movinyl 6969D: Acrylic emulsion manufactured by Japan Coating Resin Co., Ltd. (solid content: 42%, Tg: 71°C) Acrylic emulsion Movinyl 6899D: Acrylic emulsion manufactured by Japan Coating Resin Co., Ltd. (solid content: 46%, Tg: 49°C) Urethane dispersion IMPRANIL DL3040: Urethane dispersion manufactured by Sumika Covestro Urethane Co., Ltd. (solid content: 40%) Urethane dispersion DISPERCOLL U53: Urethane dispersion manufactured by Sumika Covestro Urethane Co., Ltd. (solid content: 40%)

[0132] [Examples 1 to 25, Comparative Examples 1 to 13] <Preparation of Mixture> An active energy ray-curable resin composition was obtained by mixing a urethane (meth)acrylate compound (A), a glycerin skeleton-containing (meth)acrylate (B), and an ethylenically unsaturated monomer (C) in the amounts shown in Tables 1 to 6. Then, purified water, a photopolymerization initiator (D), a leveling agent, an acrylic emulsion, and a urethane dispersion were mixed in the amounts shown in Tables 1 to 6 to obtain an active energy ray-curable emulsion composition. For the acrylic emulsion and urethane dispersion in Table 5, the amounts are shown in terms of solid content.

[0133] Specifically, the urethane (meth)acrylate compound (A), the glycerin skeleton-containing (meth)acrylate (B), and the ethylenically unsaturated monomer (C) were weighed into a glass bottle, preheated (60°C), and then stirred and mixed using a disperser. Purified water was added dropwise while stirring and mixing, and the photopolymerization initiator (D), leveling agent, acrylic emulsion, and urethane dispersion were added, followed by further stirring and mixing to prepare the composition.

[0134] The compositions prepared in the above Examples and Comparative Examples were subjected to the following various measurements and evaluations. The results are shown in Tables 1 to 6 below. Note that for Comparative Examples 3, 4, and 13, some measurements were not performed because separation and precipitation occurred within a few days.

[0135] <Liquid properties> [Liquid appearance] The appearance of the prepared active energy ray-curable emulsion composition was visually inspected and evaluated based on the following criteria. (Evaluation criteria) 〇 Uniform dispersion without settling △: Little sediment, mostly uniformly dispersed × Precipitation

[0136] [Particle size distribution] The volume average particle size (volume-based average diameter) (nm) of the prepared active energy ray-curable emulsion composition was measured using a laser scattering / diffraction device (LA950V2, manufactured by Horiba, Ltd.).

[0137] [viscosity] The viscosity (mPa·s) of the prepared active energy ray-curable emulsion composition at 25°C was measured using an E-type viscometer (100 rpm).

[0138] <Coating evaluation> [Preparation of coating film with PET substrate] The prepared active energy ray-curable emulsion composition was applied to a 125 μm thick, easily adhesive PET sheet (Cosmoshine A4360, manufactured by Toyobo Co., Ltd.) using a bar coater No. 16 so that the film thickness after drying would be 10 μm. The sheet was dried at 70°C for 5 minutes and then irradiated with ultraviolet light (cumulative irradiation dose 450 mJ / cm) in two passes using one high-pressure mercury lamp from a height of 18 cm at a conveyor speed of 3.4 m / min. 2 ) to form a cured coating film (coating film sample for evaluation).

[0139] [Pencil hardness] Using the coating film sample for evaluation coated on the highly adhesive PET, pencil hardness was measured under a load of 750 g in accordance with the method of JIS K 5600-5-4:1999.

[0140] [Bending test] The coating samples for evaluation coated on the above-mentioned highly adhesive PET were evaluated for flexibility using a cylindrical mandrel bending tester in accordance with JIS K 5600-5-1: 1999. When the cured coating for evaluation was wrapped around a test rod, the maximum diameter (integer value, mm) at which cracking or peeling occurred was measured.

[0141] [Optical measurement] (Total light transmittance and haze) The transparency of the coating film sample for evaluation coated on the easy-adhesion PET was measured using a haze meter ("NDH 4000" manufactured by Nippon Denshoku Industries Co., Ltd.) to measure the total light transmittance (%) and haze value (%).

[0142] (b * value) The degree of yellowing of the coating film sample for evaluation coated on the above-mentioned highly adhesive PET was measured by the b* value using a color difference meter ("SE 6000" manufactured by Nippon Denshoku Industries Co., Ltd.).

[0143] [Preparation of coating film with PC substrate] The prepared active energy ray-curable emulsion composition was applied to a polycarbonate (PC) plate (manufactured by Nippon Test Panel Co., Ltd.) using a bar coater No. 16 so that the film thickness after drying would be 10 μm, and the plate was dried at 70°C for 5 minutes. The plate was then irradiated with ultraviolet light (cumulative irradiation dose 450 mJ / cm) in two passes using one high-pressure mercury lamp at a height of 18 cm and a conveyor speed of 3.4 m / min. 2 ) to form a cured coating film (coating film sample for evaluation).

[0144] [exterior] The surface condition of the evaluation coating film sample coated on the polycarbonate (PC) plate was observed and evaluated according to the following criteria. (Evaluation criteria) A uniform coating was obtained... "○" A nearly uniform coating was obtained... "△" Defects such as unevenness or foreign matter are found in the coating... "X"

[0145] [Adhesion] Using the evaluation coating film sample coated on the polycarbonate (PC) plate, a 1 mm cross-cut checkerboard adhesion test (test method conforming to JIS K5600-5-6) was performed to evaluate the adhesion between the cured coating film and the PC plate, and the number of squares that were not peeled or chipped was counted.

[0146] [Hot water immersion test] The evaluation coating film samples coated on the PC boards were immersed in purified water maintained at 80°C for 2.5 hours, and immediately after removal, the appearance of the cured coating film and PC adhesion were evaluated as follows. Regarding PC adhesion, the number of squares that were not peeled or chipped, which had been cross-cut to evaluate PC adhesion before the boiling water resistance test as described above, was counted again. (Appearance evaluation criteria) It has not turned white and remains transparent... "Good" Some bleaching is observed... "△" Whitening is observed throughout the coating... "X"

[0147] [Preparation of coating film with ABS white substrate] The prepared active energy ray-curable emulsion composition was applied to an acrylonitrile-butadiene-styrene copolymer synthetic resin (ABS) white plate (manufactured by Nippon Test Panel Co., Ltd.) using a bar coater No. 18 so that the film thickness after drying would be 12 μm. After leaving it to stand for 5 minutes, it was dried at 60°C for 15 minutes and then irradiated with ultraviolet light (cumulative irradiation dose 500 mJ / cm) in two passes using one high-pressure mercury lamp from a height of 22 cm at a conveyor speed of 3.8 m / min. 2 ) to form a cured coating film (coating film sample for evaluation).

[0148] [exterior] The surface condition of the evaluation coating film sample coated on the ABS white plate was observed and evaluated according to the following criteria. (Evaluation criteria) A uniform coating was obtained... "○" A nearly uniform coating was obtained... "△" Defects such as unevenness or foreign matter are found in the coating... "X"

[0149] [Adhesion] Using the evaluation coating film samples coated on the above-mentioned ABS white boards, a 1 mm cross-cut checkerboard adhesion test (test method conforming to JIS K5600-5-6) was performed to evaluate the adhesion between the cured coating film and the ABS board, and the number of squares that were not peeled off or chipped was counted.

[0150] [Hot water immersion test] The evaluation coating film samples coated on the above white ABS plates were immersed in purified water maintained at 85°C for 2 hours, and immediately after removal, the appearance of the cured coating film and ABS adhesion were evaluated as follows. Regarding ABS adhesion, the number of squares that were not peeled or chipped, which had been cross-cut to evaluate ABS adhesion before the boiling water resistance test as described above, was counted again. (Appearance evaluation criteria) It has not turned white and remains transparent... "Good" Some bleaching is observed... "△" Whitening is observed throughout the coating... "X"

[0151] [Preparation of coating film with ABS black substrate] The prepared active energy ray-curable emulsion composition was applied to an acrylonitrile-butadiene-styrene copolymer synthetic resin (ABS) blackboard using a No. 18 bar coater so that the film thickness after drying would be 12 μm. After leaving it to stand for 5 minutes, it was dried at 60°C for 15 minutes and then irradiated with ultraviolet light (cumulative irradiation dose 500 mJ / cm) in two passes using one high-pressure mercury lamp from a height of 22 cm at a conveyor speed of 3.8 m / min. 2 ) to form a cured coating film (coating film sample for evaluation).

[0152] [exterior] The surface condition of the evaluation coating film sample coated on the ABS blackboard was observed and evaluated according to the following criteria. (Evaluation criteria) A uniform coating was obtained... "○" A nearly uniform coating was obtained... "△" Defects such as unevenness or foreign matter are found in the coating... "X"

[0153] [ABS adhesion] Using the evaluation coating film sample coated on the ABS blackboard, a 1 mm cross-cut checkerboard adhesion test (test method conforming to JIS K5600-5-6) was performed to evaluate the adhesion between the cured coating film and the ABS board, and the number of squares that were not peeled off or chipped was counted.

[0154] [Hot water immersion test] The evaluation coating film sample coated on the ABS blackboard was immersed in purified water maintained at 85°C for 2 hours, and immediately after removal, the appearance of the cured coating film and ABS adhesion were evaluated as follows. Regarding ABS adhesion, the number of squares that were not peeled or chipped, which had been cross-cut to evaluate ABS adhesion before the boiling water resistance test as described above, was counted again. (Evaluation criteria) It has not turned white and remains transparent... "Good" Some bleaching is observed... "△" Whitening is observed throughout the coating... "X"

[0155] [Table 1]

[0156] [Table 2]

[0157] [Table 3]

[0158] [Table 4]

[0159] [Table 5]

[0160] [Table 6]

[0161] As is clear from Tables 1 to 6 above, the active energy ray-curable emulsion compositions of Examples 1 to 25, which contained a urethane (meth)acrylate compound (A) obtained by reacting specific components and a glycerin skeleton-containing (meth)acrylate (B), had excellent self-emulsifying properties in an aqueous medium, and when coated on a substrate and cured, gave cured coating films that were high in hardness and had sufficient flexibility, and were resistant to deterioration in coating appearance such as whitening and deterioration in adhesion performance even after immersion in warm water. On the other hand, the active energy ray-curable emulsion compositions of Comparative Examples 1 to 13, which did not use the glycerin skeleton-containing (meth)acrylate (B), were inferior in self-emulsifying property in an aqueous medium, and in hardness and flexibility when coated on a substrate and cured. Even after immersion in warm water, they were prone to deterioration in the appearance of the coating film, such as whitening, and reduced adhesion performance. [Industrial Applicability]

[0162] The coating film formed by curing the active energy ray-curable resin composition of the present invention has an excellent balance between hardness and flexibility, optical properties, substrate adhesion, and hot water resistance, and is therefore very useful as a variety of coating film-forming materials, such as paints, pressure-sensitive adhesives, adhesives, tacky adhesives, inks, protective coating agents, anchor coating agents, coating agents for hard coats, magnetic powder coating binders, coatings for sandblasting, printing plates, coating agents for optical film top coats, metal vapor deposition and sputtering films, and coating agents for glass modification.

Claims

1. An active energy ray-curable resin composition comprising: a urethane (meth)acrylate compound (A) which is a reaction product of a polyvalent isocyanate compound (a1), a hydroxyl group-containing (meth)acrylate compound (a2), and an oxyalkylene group-containing compound (a3) ​​represented by the following general formula (1); and a glycerin skeleton-containing (meth)acrylate (B). 【Chemistry 1】 [In formula (1), X represents an alkylene group, Y represents a hydrogen atom, an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n represents an integer of 1 or greater.]

2. 2. The active energy ray-curable resin composition according to claim 1, wherein X in the general formula (1) is an ethylene group.

3. 2. The active energy ray-curable resin composition according to claim 1, wherein the urethane (meth)acrylate compound (A) is obtained by forming a urethane bond by a method of reacting the polyvalent isocyanate compound (a1) with the hydroxyl group-containing (meth)acrylate compound (a2), and then reacting the resulting mixture with the oxyalkylene group-containing compound (a3) ​​represented by the general formula (1).

4. 2. The active energy ray-curable resin composition according to claim 1, wherein the glycerin skeleton-containing (meth)acrylate (B) has a molecular weight of less than 500.

5. 2. The active energy ray-curable resin composition according to claim 1, wherein the glycerin skeleton-containing (meth)acrylate (B) has a viscosity at 25°C of less than 200 mPa·s.

6. 2. The active energy ray-curable resin composition according to claim 1, wherein the glycerin skeleton-containing polyfunctional (meth)acrylate (B) has an SP value calculated by the Fedors method of 9.3 to 11.

0.

7. The active energy ray-curable resin composition according to claim 1, further comprising an ethylenically unsaturated monomer (C) other than the glycerin skeleton-containing polyfunctional (meth)acrylate (B).

8. 2. The active energy ray-curable resin composition according to claim 1, wherein the content of the urethane (meth)acrylate compound (A) is 10 mass% or more and 90 mass% or less with respect to the total amount of the ethylenically unsaturated group-containing compounds contained in the active energy ray-curable resin composition.

9. The active energy ray-curable resin composition according to claim 1 , further comprising a photopolymerization initiator (D).

10. An active energy ray-curable emulsion composition comprising the active energy ray-curable resin composition according to any one of claims 1 to 9 and an aqueous medium.

11. An adhesive composition comprising the active energy ray-curable resin composition according to any one of claims 1 to 9.

12. A coating composition comprising the active energy ray-curable resin composition according to any one of claims 1 to 9.

13. A laminate having at least one cured coating film formed from the coating composition according to claim 12.

14. A method for producing the laminate according to claim 13, comprising the steps of applying the coating composition according to claim 12 to a substrate and curing the applied coating composition.

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