JP7711998B1 - Curable resin composition and cured product thereof - Google Patents

Abstract

The present invention provides a curable composition capable of forming a hard coat layer having excellent heat resistance and moist heat resistance.
[Solution] The composition contains a (meth)acrylate having a hydroxyl value in a specific range and a structure derived from a polyhydric alcohol, a urethane (meth)acrylate obtained from a specific polyisocyanate, and a mixture of (meth)acrylates having alkylene oxide structural units in a different specific range of number.
[Selection diagram] None

Description

The present invention relates to a curable resin composition and a cured product thereof, which comprises a mixture of a urethane (meth)acrylate obtained from a (meth)acrylate with a specific hydroxyl value having a structure derived from a polyhydric alcohol and a specific polyisocyanate, and a polyfunctional (meth)acrylate having a different number of alkylene oxide units.

In recent years, resin films and molded products such as polyethylene terephthalate (PET) resin, polycarbonate (PC) resin, poly(methyl meth)acrylate (PMA or PMMA) resin, etc. are widely used in many devices and their parts, such as liquid crystal televisions, mobile phones, communication devices, office equipment, and household appliances, instead of glass substrates and molded products. These resins are lighter than glass and easier to process, but they have poor weather resistance and their surfaces are easily scratched, so it is common to provide a protective layer. For this reason, the protective layer is required to have hardness and scratch resistance, but it is also used in curved parts of molded products and displays, and in recent years, it has also begun to be used in foldable or rollable portable display devices, so high flexibility is required. In addition, when a coating agent is applied to the film and hardened, it is required that curling and cracking do not occur due to hardening shrinkage.

In addition, devices used outdoors, such as devices installed in automobiles and portable devices, are now required to have higher heat resistance and resistance to moist heat.

To meet these demands, various curable resin compositions have been proposed as coating agents for resin substrates.

For example, in order to provide a coating agent capable of forming a coating layer that combines high hardness and high flexibility, an active energy ray-curable coating agent has been proposed that contains a mixture of urethane acrylates synthesized from pentaerythritol acrylates (PETA) with different hydroxyl values and inorganic fine particles (Patent Document 1).

In addition, a curable composition has been proposed that contains a multi-branched acrylate, a bifunctional urethane acrylate, an ultraviolet absorber, and a photopolymerization initiator in a specific ratio, with the aim of providing a curable composition that has a viscosity suitable for spray coating even with a high solid content, suppresses precipitation of the ultraviolet absorber, and can produce a cured product with excellent weather resistance and warm water resistance (Patent Document 2).

In addition, for the purpose of providing a curable resin composition capable of forming a hard coat layer with high hardness without curling or cracking during the formation or processing of the hard coat layer, a curable resin composition is provided that contains a urethane (meth)acrylate (A) which is a reaction product of norbornane diisocyanate (a1) and a compound (a2) having a hydroxyl group and a (meth)acryloyl group, and a bifunctional (meth)acrylate monomer (B) in which an ethoxy structure has been introduced between the terminal (meth)acryloyl groups, in a predetermined ratio (Patent Document 3).

In addition, for the purpose of providing a coating material composition capable of forming a cross-linked cured coating film having excellent weather resistance while improving abrasion resistance, particularly abrasion resistance according to the Taber abrasion test, on the surface of a substrate, a coating material composition has been provided that contains a polyfunctional (meth)acryloyl group-containing (iso)cyanurate compound as the main component, polypentaerythritol having a (meth)acryloyl group, a urethane poly(meth)acrylate compound having a radically polymerizable unsaturated double bond, a cyanurate having a (meth)acryloyl group, an ultraviolet absorber, a hindered amine-based light stabilizer, and a photopolymerization initiator (Patent Document 4).

However, none of these coating agents and curable compositions are intended to improve heat resistance and moist heat resistance, and the resulting cured products are insufficient in terms of adhesion and transparency under high heat or high moist heat conditions. For this reason, there is still a demand for curable compositions that can impart high heat resistance and moist heat resistance.

Patent No. 6845586 Patent No. 7452588 Patent No. 6481302 Publication No. 4204106

In one embodiment, the present invention aims to meet such demands by providing a curable composition capable of forming a hard coat layer having excellent heat resistance and moist heat resistance. In another embodiment, the present invention aims to provide a cured product having excellent heat resistance and moist heat resistance, or a product having the same.

In order to achieve the above object, the present inventors have investigated various compositions of curable compositions, and have found that when a composition containing a (meth)acrylate having a hydroxyl value in a specific range and a structure derived from a polyhydric alcohol, more preferably a mixture of (meth)acrylates having a hydroxyl value in a different specific range and a structure derived from a polyhydric alcohol, and a mixture of a urethane (meth)acrylate obtained from a specific polyisocyanate and a (meth)acrylate having an alkylene oxide structural unit in a different specific range of number, is cured on a resin substrate, the obtained cured product maintains adhesion and transparency even after being exposed to high heat conditions or high humidity and heat conditions for a long period of time, which led to the present invention.

That is, in its embodiments, the present invention provides the following curable resin composition, cured layer, method for forming the same, and article having the same.
[1] A urethane (meth)acrylate (A) obtained by reacting (a1) a (meth)acrylate having a structure derived from a polyhydric alcohol and having a hydroxyl value of 90 to 300 mgKOH/g, (a2) a polyisocyanate selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinking structure, an aromatic isocyanate, and a hydrogenated product thereof, and optionally a polyol (a3),
and an alkylene oxide-modified (meth)acrylate (B), wherein the alkylene oxide-modified (meth)acrylate (B) is
A (meth)acrylate (B1) having an average number of repeating alkylene oxide units of 0 to 2.0;
Optionally, a curable resin composition comprising: a (meth)acrylate (B2) having an average number of repeating alkylene oxide units of 3.0 to 5.0; and a (meth)acrylate (B3) having an average number of repeating alkylene oxide units of 6.0 to 8.0.
[2] The alkylene oxide-modified (meth)acrylate (B) is represented by the following formula (1):

(In the formula, R ¹ is hydrogen or a methyl group, a trimethylolpropane residue, a bisphenol A residue, or an erythritol residue, m is an integer of 2 to 3, and n is an integer of 0 to 8.)
The alkylene oxide-modified (meth)acrylate has a structure represented by
5 to 50% by mass of a (meth)acrylate (B1) of formula (1) in which the average of n is 0 to 2.0,
The curable resin composition according to [1], comprising: 20 to 90 mass% of a (meth)acrylate (B2) of formula (1) in which an average of n is 3.0 to 5.0; and 5 to 30 mass% of a (meth)acrylate (B3) of formula (1) in which an average of n is 6.0 to 8.0.
[3] The curable resin composition according to [1] or [2], wherein the urethane (meth)acrylate (A) comprises a urethane (meth)acrylate (A2) obtained by reacting a polyhydric alcohol-derived structure-derived (meth)acrylate (a1-2) having a hydroxyl value of 200 to 300 mgKOH/g, a polyvalent isocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure, an aromatic isocyanate, and a hydrogenated product thereof, and optionally a polyol (a3).
[4] The urethane (meth)acrylate (A) is
The curable resin composition according to [1] or [2], comprising a urethane (meth)acrylate (A1) obtained by reaction of a (meth)acrylate (a1-1) having a structure derived from a polyhydric alcohol and having a hydroxyl value of 110 to 180 mgKOH/g, a polyisocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure, an aromatic isocyanate, and a hydrogenated product thereof, and optionally a polyol (a3).
[5] The urethane (meth)acrylate (A) is
a urethane (meth)acrylate (A1) obtained by reacting a (meth)acrylate (a1-1) having a structure derived from a polyhydric alcohol and having a hydroxyl value of 90 to 180 mgKOH/g, a polyisocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure, an aromatic isocyanate, and a hydrogenated product thereof, and an arbitrary polyol (a3);
The curable resin composition according to [1] or [2], comprising: (a1-2) a (meth)acrylate having a structure derived from a polyhydric alcohol and having a hydroxyl value of 200 to 300 mgKOH/g; (a2) a polyvalent isocyanate selected from aliphatic isocyanates, alicyclic isocyanates having no crosslinking structure, aromatic isocyanates, and hydrogenated products thereof; and optionally a urethane (meth)acrylate (A2) obtained by reaction with a polyol (a3).
[6] The urethane (meth)acrylate (A) is
The curable resin composition according to [1] or [2], which comprises a urethane (meth)acrylate (A1) obtained by reacting a (meth)acrylate (a1-1) having a structure derived from a polyhydric alcohol and having a hydroxyl value of 110 to 180 mgKOH/g, a polyvalent isocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure, an aromatic isocyanate, and a hydrogenated product thereof, and optionally a polyol (a3); and a (meth)acrylate (a1-2) having a structure derived from a polyhydric alcohol and having a hydroxyl value of 200 to 300 mgKOH/g, a polyvalent isocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure, an aromatic isocyanate, and a hydrogenated product thereof, and optionally a polyol (a3).
[7] The curable resin composition according to [5] or [6], wherein the mass ratio of the urethane (meth)acrylate (A1) to the urethane (meth)acrylate (A2) is 10:1 to 1:2.
[8] The curable resin composition according to any one of [1] to [7], wherein the urethane (meth)acrylate (A) has a structure derived from at least one polyhydric alcohol selected from the group consisting of glycerin, pentaerythritol, dipentaerythritol, and tripentaerythritol.
[9] The curable resin composition according to [8], wherein the urethane (meth)acrylate (A) has a structure derived from either or both of dipentaerythritol and tripentaerythritol.
[10] The curable resin composition according to any one of [1] to [9], wherein the polyisocyanate (a2) is an alicyclic isocyanate having no crosslinked structure.
[11] The curable resin composition according to [10], wherein the alicyclic isocyanate is isophorone diisocyanate or dicyclohexylmethane diisocyanate.
[12] The curable resin composition according to any one of [1] to [11], wherein the hydroxyl value of the urethane (meth)acrylate (A) is 0.1 to 10 mgKOH/g.
[13] The curable resin composition according to any one of [1] to [12], wherein the alkylene oxide-modified (meth)acrylate (B) is selected from ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, ethylene oxide-modified bisphenol A diacrylate, propylene oxide-modified bisphenol A diacrylate, ethylene oxide-modified pentaerythritol tetraacrylate, and propylene oxide-modified pentaerythritol tetraacrylate.
[14] The curable resin composition according to any one of [1] to [13], further comprising 0.01 to 10 parts by mass of a polymerization initiator relative to a total of 100 parts by mass of the urethane (meth)acrylate (A) and the (meth)acrylate (B).
[15] The curable resin composition according to [14], wherein the polymerization initiator is one or more thermal polymerization initiators selected from an azo compound-based polymerization initiator and an organic peroxide-based polymerization initiator.
[16] The curable resin composition according to [14], wherein the polymerization initiator is one or more photopolymerization initiators selected from the group consisting of acetophenone-based polymerization initiators, benzophenone-based polymerization initiators, thioxanthone-based polymerization initiators, and acylphosphine-based polymerization initiators.
[17] The curable resin composition according to [14], wherein the polymerization initiator is a thermal and photopolymerization initiator selected from an azo compound-based polymerization initiator and an organic peroxide.
[18] The curable resin composition according to any one of [1] to [17], further comprising 0.1 to 15 parts by mass of one or more of the group consisting of a benzotriazole-based light stabilizer, a triazine-based light stabilizer, a cyanoacrylate-based light stabilizer, and a hindered amine-based light stabilizer, relative to a total of 100 parts by mass of the urethane (meth)acrylate (A) and the (meth)acrylate (B).
[19] A cured layer obtained by curing the curable resin composition according to any one of [1] to [18].
[20] An article having the cured layer according to [19] on the entire surface, one surface or part of an inorganic or organic substrate.
[21] A method for forming a coating layer, comprising applying the curable resin composition according to any one of [1] to [18] onto a substrate, and irradiating the curable resin composition with active energy rays or heating the curable resin composition to cure the curable resin composition.

In one embodiment of the present invention, the curable resin composition is cured on a resin substrate, and the cured product maintains adhesion and transparency even after prolonged exposure to high heat or high humidity and heat conditions.

Here, the main terms used in this specification are defined.
In this specification, the term "hydroxyl value" refers to the number of milligrams of potassium hydroxide equivalent to the hydroxyl groups in 1 g of sample, and is determined by esterifying a sample with a pyridine solution of phthalic anhydride and titrating the excess reagent with a potassium hydroxide solution according to the Polyether Test Method for Polyurethanes described in Japanese Industrial Standards (JIS) K1557. In addition, in this specification, the term "hydroxyl value" refers to a hydroxyl value as an average value. Thus, for example, "a (meth)acrylate with a hydroxyl value of 90 mg KOH/g" refers to a mixture of (meth)acrylates having the same or different hydroxyl values with an average hydroxyl value of 90 mg KOH/g.
In addition, in this specification, "polyhydric alcohol" means a compound having a difunctional or higher hydroxyl group, and "(meth)acrylate having a structure derived from a polyhydric alcohol" means a (meth)acrylate obtained by reacting a polyhydric alcohol with acrylic acid or methacrylic acid, etc., and having a part of the structure of the polyhydric alcohol. For example, pentaerythritol corresponds to "polyhydric alcohol", and in this case, "(meth)acrylate having a structure derived from a polyhydric alcohol" includes pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. On the other hand, for example, "lactone" does not correspond to "polyhydric alcohol", and "lactone-modified (meth)acrylate" does not correspond to "(meth)acrylate having a structure derived from a polyhydric alcohol".
In addition, in this specification, the term "(meth)acrylic" is used to mean both acrylic and methacrylic. Thus, for example, the term "(meth)acrylic acid" means both or either of acrylic acid and methacrylic acid. Similarly, the term "(meth)acrylate" means both or either of acrylate and methacrylate.
In addition, the term "pentaerythritol (meth)acrylate" in this specification is used to collectively refer to pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate, and includes any one of these compounds or a mixture of two or more of these compounds.
In addition, the term "dipentaerythritol (meth)acrylate" in this specification is used to collectively refer to dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, and includes any one of these compounds or a mixture of two or more of these. The same is true for the term "tripentaerythritol (meth)acrylate."
In addition, the term "glycerin (meth)acrylate" in this specification is used to collectively refer to glycerin mono(meth)acrylate, glycerin di(meth)acrylate, and glycerin tri(meth)acrylate, and includes any one of these compounds or a mixture of two or more of these compounds.
Moreover, the term "polyisocyanate" refers to a compound having two or more isocyanate groups in one molecule.
In addition, the "isocyanate (NCO) amount" in this specification refers to a value measured by a potentiometer in accordance with JIS K 1603-1 B method.
In addition, in this specification, "alkylene oxide-modified (meth)acrylate (B)" means a mixture of (meth)acrylates that contains at least an alkylene oxide-modified (meth)acrylate and may optionally also contain an alkylene oxide-unmodified (meth)acrylate.
In addition, the term "molecular weight" as used herein means weight average molecular weight, and in this specification refers to a value measured by gel permeation chromatography (GPC).
Unless otherwise specified, the term "molecular weight" used in this specification means the weight average molecular weight (measured by GPC using SHODEX KF-806M manufactured by Showa Denko).
In addition, the term "viscosity" in this specification refers to a value measured according to JIS Z 8803 using a BM type viscometer.
Unless otherwise specified, various operations and measurements of physical properties are carried out under conditions of room temperature (20 to 25° C.) and relative humidity of 40 to 60%.

The following describes an embodiment of the present invention. However, the present invention is not limited to the following embodiment.

1. Curable Resin Composition In one embodiment, the present invention relates to a curable resin composition comprising a urethane (meth)acrylate (A) having a specific hydroxyl value and a specific alkylene oxide-modified (meth)acrylate (B).

1-1. Urethane (meth)acrylate (A)
The urethane (meth)acrylate (A) is obtained by reacting a (meth)acrylate (a1) having a hydroxyl value of 90 to 300 mgKOH/g, a polyisocyanate (a2), and optionally a low molecular weight polyol (a3). In the reaction between the (meth)acrylate (a1) having such a hydroxyl value and the polyisocyanate (a2), the proportion of urethane bonds per molecule of the urethane (meth)acrylate (A) and the molecular weight fall within a certain range, and a cured product having excellent heat resistance and moist heat resistance can be obtained.

As the (meth)acrylate (a1) having a hydroxyl value of 90 to 300 mgKOH/g, a (meth)acrylate having a hydroxyl value of 90 to 300 mgKOH/g due to a structure derived from a polyhydric alcohol is preferred. The structure derived from a polyhydric alcohol is not particularly limited, but a structure derived from at least one selected from the group consisting of glycerin, pentaerythritol, dipentaerythritol, and tripentaerythritol is preferred. In particular, a (meth)acrylate having either or both of a structure derived from dipentaerythritol and tripentaerythritol is preferred in terms of the moist heat resistance of the cured product.

Examples of (meth)acrylates (a1) include glycerin (meth)acrylates such as glycerin mono(meth)acrylate, glycerin di(meth)acrylate, and glycerin tri(meth)acrylate; pentaerythritol (meth)acrylates such as pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, and di Dipentaerythritol (meth)acrylates such as pentaerythritol tetra(meth)acrylate and dipentaerythritol penta(meth)acrylate; tripentaerythritol (meth)acrylates such as tripentaerythritol mono(meth)acrylate, tripentaerythritol di(meth)acrylate, tripentaerythritol tri(meth)acrylate, tripentaerythritol tetra(meth)acrylate, tripentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, and tripentaerythritol hepta(meth)acrylate.

From the viewpoint of the moist heat resistance of the cured product, the (meth)acrylate (a1) is preferably a (meth)acrylate having a hydroxyl value of 90 to 180 mgKOH/g, more preferably a (meth)acrylate having a hydroxyl value of 100 to 150 mgKOH/g. On the other hand, from the viewpoint of the heat resistance of the cured product, a (meth)acrylate having a hydroxyl value of 200 to 300 mgKOH/g is preferred, more preferably a (meth)acrylate having a hydroxyl value of 250 to 300 mgKOH/g.

In the (meth)acrylate (a1), a (meth)acrylate (mixture) having a desired hydroxyl value can be obtained, for example, by mixing the same or different (meth)acrylates and determining the mixing ratio in consideration of the hydroxyl values of the individual compounds.
For example, when the (meth)acrylate (b1) having a hydroxyl value of 90 to 180 mgKOH/g is composed of pentaerythritol polyacrylate, for example, a mixture of pentaerythritol triacrylate (hydroxyl value 188 mgKOH/g) containing one hydroxyl group and one or more of pentaerythritol monoacrylate, pentaerythritol diacrylate, and pentaerythritol tetraacrylate may be used, resulting in a (meth)acrylate mixture containing pentaerythritol triacrylate in the range of 30 to 70%.
In addition, when it is composed of glycerin polyacrylate, for example, it may be a mixture of glycerin diacrylate (hydroxyl value 280 mgKOH/g) containing one hydroxyl group and one or more of glycerin monoacrylate and glycerin triacrylate, and may be a (meth)acrylate mixture containing glycerin diacrylate in the range of 20 to 55%.
In addition, when it is composed of dipentaerythritol polyacrylate, for example, a mixture of dipentaerythritol pentaacrylate (hydroxyl value 106 mgKOH/g) containing one hydroxyl group, dipentaerythritol tetraacrylate (hydroxyl value 238 mgKOH/g) containing two hydroxyl groups, and one or more of dipentaerythritol monoacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate may be used, resulting in a (meth)acrylate mixture containing 5 to 85% dipentaerythritol pentaacrylate and 5 to 75% dipentaerythritol tetraacrylate.
Furthermore, when composed of tripentaerythritol polyacrylate, for example, a mixture of tripentaerythritol hexaacrylate containing two hydroxyl groups (hydroxyl value 161 mgKOH/g) and one or more of tripentaerythritol monoacrylate, tripentaerythritol diacrylate, tripentaerythritol triacrylate, tripentaerythritol tetraacrylate, tripentaerythritol pentaacrylate, tripentaerythritol heptaacrylate, and tripentaerythritol octaacrylate may be used, resulting in a (meth)acrylate mixture containing 5 to 55% of tripentaerythritol hexaacrylate.

Similarly, when the (meth)acrylate (b2) having a hydroxyl value of 200 to 300 mgKOH/g is composed of pentaerythritol polyacrylate, for example, a mixture of pentaerythritol diacrylate (hydroxyl value 459 mgKOH/g) containing two hydroxyl groups and one or more of pentaerythritol monoacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate may be used, resulting in a (meth)acrylate mixture containing 20 to 50% of pentaerythritol diacrylate.
In addition, when it is composed of glycerin polyacrylate, for example, it may be a mixture of glycerin diacrylate (hydroxyl value 280 mgKOH/g) containing one hydroxyl group and one or more of glycerin monoacrylate and glycerin triacrylate, and may be a (meth)acrylate mixture containing glycerin diacrylate in the range of 50 to 80%.
In addition, when dipentaerythritol polyacrylate is used, for example, a mixture of dipentaerythritol tetraacrylate (hydroxyl value 238 mgKOH/g) containing two hydroxyl groups and one or more of dipentaerythritol monoacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate may be used, resulting in a (meth)acrylate mixture containing dipentaerythritol tetraacrylate in the range of 50 to 85%.
Furthermore, when composed of tripentaerythritol polyacrylate, for example, a mixture of tripentaerythritol pentaacrylate containing two hydroxyl groups (hydroxyl value 262 mgKOH/g) and one or more of tripentaerythritol monoacrylate, tripentaerythritol diacrylate, tripentaerythritol triacrylate, tripentaerythritol tetraacrylate, tripentaerythritol hexaacrylate, tripentaerythritol heptaacrylate, and tripentaerythritol octaacrylate may be used, resulting in a (meth)acrylate mixture containing 40 to 85% tripentaerythritol pentaacrylate.

There are no particular limitations on the polyisocyanate (a2), and examples include aliphatic, alicyclic, or aromatic isocyanates and polyisocyanates, as well as hydrogenated products thereof. In terms of obtaining a cured product with high resistance to moist heat, aliphatic isocyanates, alicyclic isocyanates without a crosslinked structure, aromatic isocyanates or hydrogenated products thereof are preferred, and alicyclic isocyanates without a crosslinked structure are particularly preferred.

Examples of polyisocyanates (a2) include isophorone diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, polymeric MDI, tetramethylxylylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate methyl ester, methylenebis(4,1-cyclohexylene)-diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, tolylene diisocyanate (e.g., 2,4-tolylene diisocyanate), phenylene diisocyanate (1,4-phenylene diisocyanate), diisocyanate), diphenyl diisocyanate (e.g., 4,4-diphenyl diisocyanate, 3,3-dimethyl-4,4-diphenylene diisocyanate), diphenylmethane diisocyanate (4,4-diphenylmethane diisocyanate), naphthalene diisocyanate (e.g., 1,5-naphthalene diisocyanate), xylylene diisocyanate, adducts of diisocyanate compounds and polyol compounds such as trimethylolpropane, and isocyanate derivatives such as biuret and isocyanurate compounds of diisocyanate compounds. Among these, from the viewpoint of improving the moisture and heat resistance of the cured product, 1,3-bis(isocyanatemethyl)cyclohexane, isophorone diisocyanate, or dicyclohexylmethane diisocyanate is preferred, and dicyclohexylmethane diisocyanate is more preferred. Commercially available products include VESTANAT (registered trademark) IPDI manufactured by Evonik, VESTANAT (registered trademark) H12MDI manufactured by Evonik, Duranate D-201, TPA-100, TKA-100, 24A-100, 22A-75P, P301-75E, etc. manufactured by Asahi Kasei Corporation, Coronate HX, 2715, etc. manufactured by Tosoh Corporation, HDI manufactured by Tosoh Corporation, Takenate (registered trademark) D160N, D-170N, D-170HN, D-172N, D-177N, 600, etc. manufactured by Mitsui Chemicals, Inc. These may be used alone or in combination of two or more types.

The urethane (meth)acrylate (A) may be synthesized by reacting a (meth)acrylate (a1) with a polyisocyanate (a2) together with, if necessary, a polyol (a3).
The polyol preferably has a solubility in water at 25° C. of 3.0 g/L or more, more preferably 3.5 g/L or more, and even more preferably 4.0 g/L or more, and is particularly preferably soluble in water in any ratio.
Examples of polyols include dihydric alcohols, trihydric alcohols, and condensates thereof. Specific examples of polyols include alkylene glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, and 1,3-butanediol; polyalkylene glycols such as diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; glycerin and glycerin condensates such as glycerin, diglycerin, and triglycerin; and triols such as 1,2,4-butanetriol, 1,2,5-pentanetriol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, and trimethylolpropane.
The average molecular weight of polyalkylene glycols such as polyethylene glycol and polypropylene glycol is preferably 2,000 or less, more preferably 1,000 or less, and even more preferably 400 or less.
Among the above polyols, ethylene glycol, propylene glycol, 1,3-butanediol, dipropylene glycol, polyethylene glycol (molecular weight 400 or less), glycerin, and diglycerin are more preferred, and propylene glycol, 1,3-butanediol, dipropylene glycol, polyethylene glycol (molecular weight 400 or less), and glycerin are more preferred. Furthermore, polyols having a low molecular weight (specifically, a molecular weight of 100 or less, preferably a molecular weight of 50 to 100) are preferred in that they have little effect on the heat resistance and moist heat resistance hardness of the cured product.
The content of the low molecular weight polyol (a3) in the reaction composition is usually in the range of 0 to 10.

By efficiently reacting the (meth)acrylate (a1) with the polyisocyanate (a2) and reducing the amount of residual hydroxyl groups in the resulting urethane (meth)acrylate (A), the heat resistance and moist heat resistance of the cured product can be significantly improved. From this perspective, it is more preferable to mix the (meth)acrylate (a1) having a hydroxyl value of 90 to 300 mgKOH/g, the polyisocyanate (a2), and the polyol (a3) in such a ratio that the ratio of the number of moles of isocyanate groups to the sum of the number of moles of hydroxyl groups (number of moles of isocyanate groups/sum of the number of moles of hydroxyl groups) calculated by the following formulas (1) and (2) is 0.95 to 1.05.
Sum of moles of hydroxyl groups=(amount of (a1)/hydroxyl equivalent of (a1))+(amount of (a3)/hydroxyl equivalent of (a3)) (1)
(In the formula, the hydroxyl group equivalent means the molecular weight/the number of hydroxyl groups.)
Molar number of isocyanate groups=Amount of (a2)/Isocyanate equivalent of (a2)
(In the formula, the isocyanate equivalent of (a2) means the molecular weight/the number of isocyanate groups.)

The reaction between the (meth)acrylate (a1), the polyisocyanate (a2), and optionally the low molecular weight polyol (a3) may be carried out under conditions for a typical urethane reaction. For example, these compounds may be dissolved in an organic solvent, and then a catalyst, a polymerization inhibitor, etc. may be added as appropriate, followed by heating to carry out the reaction.

Examples of organic solvents include aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; esters or ether esters such as ethyl acetate, butyl acetate, and methoxybutyl acetate; ethers such as diethyl ether, tetrahydrofuran, monoethyl ether of ethylene glycol, monobutyl ether of ethylene glycol, monomethyl ether of propylene glycol, and monoethyl ether of diethylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, and cyclohexanone; amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; and sulfoxides such as dimethyl sulfoxide.

Examples of catalysts include inorganic bismuth; organic tin compounds such as dioctyltin, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate; and tertiary amine compounds such as triethylamine, triethylenediamine, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU). Among these, inorganic bismuth is particularly preferred because it does not contain tin.

From the viewpoint of preventing the C═C bond from reacting and gelling, a polymerization inhibitor may be added, and examples of polymerization inhibitors that can be used include phenothiazine, tri-p-nitrophenylmethyl, di-p-fluorophenylamine, diphenylpicrylhydrazyl, N-(3-N-oxyanilino-1,3-dimethylbutylidene)aniline oxide, benzoquinone, hydroquinone, methoquinone, butylcatechol, nitrosobenzene, picric acid, dithiobenzoyl disulfide, cupferron, and copper(II) chloride. From the viewpoint of the polymerization inhibition effect, methoquinone is preferred. These polymerization inhibitors may be used alone or in combination of two or more.
The reaction temperature varies depending on the catalyst, but is usually from 50 to 120°C.

The resulting urethane (meth)acrylate (A) has a low residual hydroxyl value, which results in a urethane (meth)acrylate with a higher number of functional groups and molecular weight. In addition, by reducing the hydrophilic residual hydroxyl groups, the heat resistance and moist heat resistance of the cured product can be significantly improved. For this reason, it is preferable that the urethane (meth)acrylate (A) has a low residual hydroxyl group. Specifically, a hydroxyl value of 15 mgKOH/g or less is preferable, a urethane (meth)acrylate (A) of 0.1 to 10 mgKOH/g is more preferable, and a urethane (meth)acrylate (A) of 0.1 to 7 mgKOH/g is particularly preferable.

In addition, the molecular weight of the urethane (meth)acrylate (A2) is preferably from 2,000 to 20,000, and more preferably from 3,000 to 18,000, from the viewpoint of adhesion of the cured product under high temperature and high humidity and heat conditions.
In view of compatibility with the urethane (meth)acrylate (A1) and adhesion and transparency under high humidity and heat conditions, the molecular weight of the urethane (meth)acrylate (A1) is preferably from 1,000 to 5,000, and more preferably from 1,200 to 4,000.

In a preferred embodiment, the coating agent contains a mixture of urethane (meth)acrylate (A1) and urethane (meth)acrylate (A2). The urethane (meth)acrylate (A2) can reduce the cure shrinkage of the coating film, so that the cured product has excellent adhesion at high temperatures, while the urethane (meth)acrylate (A1) improves the crosslink density of the cured coating film, preventing the penetration of moisture into the cured product and the substrate interface, and preventing the deterioration of adhesion and transparency under high humidity and heat conditions. By combining such urethane (meth)acrylates, a cured product having excellent adhesion and transparency at high temperatures and high humidity and heat conditions can be obtained.
The mass ratio (A/B) of the urethane (meth)acrylate (A1) to the urethane (meth)acrylate (A2) is not particularly limited and can be, for example, in the range of 1/5 to 9/1, preferably 1/3 to 8/1, more preferably 1/2 to 7/1, and particularly preferably 1/1 to 5/1.

The content of the urethane (meth)acrylate (A) in the coating agent can vary over a relatively wide range, and typically the coating film component in the coating agent can contain urethane (meth)acrylate (A) in the range of 5 to 95 mass%, preferably urethane (meth)acrylate (A) in the range of 10 to 90 mass%, more preferably urethane (meth)acrylate (A) in the range of 20 to 80 mass%, and particularly preferably urethane (meth)acrylate (A) in the range of 40 to 70 mass%.

1-2. Alkylene oxide-modified (meth)acrylate (B)
A curable resin composition according to one embodiment of the present invention contains an alkylene oxide-modified (meth)acrylate (B) together with the above-mentioned urethane (meth)acrylate (A). The alkylene oxide-modified (meth)acrylate (B) contains a (meth)acrylate (B1) having an average number of alkylene oxide repeating units of 0 to 2.0, and optionally a (meth)acrylate (B2) having an average number of alkylene oxide repeating units of 3.0 to 5.0, and a (meth)acrylate (B3) having an average number of alkylene oxide repeating units of 6.0 to 8.0.
The reason why the use of (meth)acrylates having these specific ranges of alkylene oxide addition numbers results in good heat-resistant adhesion, moist heat-resistant adhesion, and moist heat-resistant transparency is not clear, but it is thought that (meth)acrylates having a smaller number of alkylene oxide additions penetrate into the substrate and improve adhesion durability due to an anchor effect, while (meth)acrylates having a larger number of alkylene oxide additions improve adhesion by reducing the internal stress of the cured product after curing with active energy rays.

The (meth)acrylate (B) is preferably a compound represented by the following formula (1):

It is a mixture of (meth)acrylates represented by the formula:
In the formula, R1 is hydrogen or a methyl group. Also, in the formula, A is a trimethylolpropane residue, a bisphenol A residue, or a pentaerythritol residue, and preferably a trimethylolpropane residue. Also, in the formula, m is an integer of 2 to 3, and preferably 2. Also, in the formula, n is an integer of 0 to 8, and preferably an integer of 0 to 7.

Examples of the alkylene oxide-modified (meth)acrylate (B) include alkylene oxide (preferably C _2-3 alkylene oxide)-modified dipentaerythritol hexa(meth)acrylate, dipentaerythritol hexa(meth)acrylate, alkylene oxide (preferably C _2-3 alkylene oxide)-modified pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkylene oxide (preferably C 2-3 alkylene oxide)-modified trimethylolpropane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, alkylene oxide (preferably C _2-3 alkylene oxide)-modified glyceryl tri(meth)acrylate, glyceryl tri(meth)acrylate, alkylene oxide (preferably C _2-3 alkylene oxide)-modified glyceryl tri(meth)acrylate, and alkylene oxide (preferably C Examples of such compounds include bisphenol A di(meth)acrylate modified with an alkylene oxide (preferably _{a C 2-3} alkylene oxide) and bisphenol A di(meth)acrylate. Among these, compounds having about 2 to 3 (meth)acrylate groups are preferred in terms of improving water resistance without deteriorating adhesion due to cure shrinkage, and in terms of being particularly superior in water resistance and improving adhesion to substrates, trimethylolpropane tri(meth)acrylate and its alkylene oxide (preferably a C _2-3 alkylene oxide) modified product and bisphenol A di(meth)acrylate and its alkylene oxide (preferably a C _2-3 alkylene oxide) modified product are more preferred.

The (meth)acrylate (B1) is selected from the above-mentioned (meth)acrylate (B) so that the number of repeating units of alkylene oxide is 0 to 2.0 on average, and the (meth)acrylate (B1) is preferably bisphenol A di(meth)acrylate, ethylene oxide (1 mol)-added bisphenol A di(meth)acrylate, ethylene oxide (2 mol)-added bisphenol A di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide (1 mol)-added trimethylolpropane tri(meth)acrylate The ethylene oxide (2 mol)-added trimethylolpropane tri(meth)acrylate is selected from the group consisting of pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (1 mol)-added pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (2 mol)-added pentaerythritol tri- and tetra(meth)acrylate, glycerin tri(meth)acrylate, ethylene oxide (1 mol)-added glycerin tri(meth)acrylate, and ethylene oxide (2 mol)-added glycerin tri(meth)acrylate. Among these, bisphenol A di(meth)acrylate and its ethylene oxide adduct, and trimethylolpropane tri(meth)acrylate and its ethylene oxide adduct are particularly preferred in terms of excellent heat-resistant adhesion and moist heat-resistant adhesion.

The (meth)acrylate (B2) is selected from the above-mentioned (meth)acrylate (B) so that the number of repeating units of the alkylene oxide is 3.0 to 5.0 on average, and the (meth)acrylate (B2) is preferably ethylene oxide (3 mol)-added bisphenol A di(meth)acrylate, ethylene oxide (4 mol)-added bisphenol A di(meth)acrylate, ethylene oxide (5 mol)-added bisphenol A di(meth)acrylate, ethylene oxide (3 mol)-added glycerin tri(meth)acrylate, ethylene oxide (4 mol)-added glycerin tri(meth)acrylate, ethylene oxide (5 mol)-added glycerin tri(meth)acrylate, ethylene oxide (3 mol)-added trimethylolpropane tri(meth)acrylate, ethylene oxide (4 mol) added trimethylolpropane tri(meth)acrylate, ethylene oxide (5 mol) added trimethylolpropane tri(meth)acrylate, ethylene oxide (3 mol) added pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (4 mol) added pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (5 mol) added pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (3 mol) added dipentaerythritol hexaacrylate, ethylene oxide (4 mol) added dipentaerythritol hexaacrylate, and ethylene oxide (5 mol) added dipentaerythritol hexaacrylate. Among these, bisphenol A di(meth)acrylate and its ethylene oxide adduct, and trimethylolpropane tri(meth)acrylate and its ethylene oxide adduct are particularly preferred because of their excellent heat-resistant adhesion and wet heat-resistant adhesion.

The (meth)acrylate (B3) is selected from the above-mentioned (meth)acrylate (B) so that the number of repeating units of the alkylene oxide is 6.0 to 8.0 on average, and the (meth)acrylate (B3) is preferably ethylene oxide (6 mol)-added bisphenol A di(meth)acrylate, ethylene oxide (7 mol)-added bisphenol A di(meth)acrylate, ethylene oxide (8 mol)-added bisphenol A di(meth)acrylate, ethylene oxide (6 mol)-added glycerin tri(meth)acrylate, ethylene oxide (7 mol)-added glycerin tri(meth)acrylate, ethylene oxide (8 mol)-added glycerin tri(meth)acrylate, ethylene oxide (6 mol)-added trimethylolpropane tri(meth)acrylate, ethylene oxide (7 mol) added trimethylolpropane tri(meth)acrylate, ethylene oxide (8 mol) added trimethylolpropane tri(meth)acrylate, ethylene oxide (6 mol) added pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (7 mol) added pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (8 mol) added pentaerythritol tri- and tetra(meth)acrylate, ethylene oxide (6 mol) added dipentaerythritol hexaacrylate, ethylene oxide (7 mol) added dipentaerythritol hexaacrylate, and ethylene oxide (8 mol) added dipentaerythritol hexaacrylate. Among these, bisphenol A di(meth)acrylate and its ethylene oxide adduct, and trimethylolpropane tri(meth)acrylate and its ethylene oxide adduct are particularly preferred because of their excellent heat-resistant adhesion and wet heat-resistant adhesion.

In order to improve both heat resistance and moist heat resistance, the alkylene oxide-modified (meth)acrylate (B) is preferably a mixture containing (B1) having an average number of repeating alkylene oxide units (n in formula (1)) of 0 to 2.0, (B2) having an average number of repeating alkylene oxide units (n in formula (1)) of 3.0 to 5.0, and (B3) having an average number of repeating alkylene oxide units (n in formula (1)) of 6.0 to 8.0.

In order to improve both the heat resistance and the moist heat resistance, the alkylene oxide-modified (meth)acrylate (B) preferably contains 5 to 50 mass% of (meth)acrylate (B1), 20 to 90 mass% of (meth)acrylate (B2), and 5 to 30 mass% of (meth)acrylate (B3), and more preferably contains 10 to 45 mass% of (meth)acrylate (B1), 30 to 80 mass% of (meth)acrylate (B2) in which n in formula (1) is 3.0 to 5.0, and 10 to 25 mass% of (meth)acrylate (B3) in which n in formula (1) is 6.0 to 8.0.

The content of the (meth)acrylate (B) in the coating agent is not particularly limited and can vary over a wide range. Usually, the coating film component of the coating agent can contain the (meth)acrylate (B) in the range of 5 to 95 mass%, preferably contains the (meth)acrylate (B) in the range of 10 to 90 mass%, more preferably contains the (meth)acrylate (B) in the range of 20 to 80 mass%, and particularly preferably contains the (meth)acrylate (B) in the range of 40 to 70 mass%.
1-3. Other ingredients

The curable resin composition may contain other components, such as a polymerization initiator, a light stabilizer, a solvent, a thickener, a flame retardant, an ultraviolet absorber, a leveling agent, and an antioxidant, as necessary.

As the polymerization initiator, either a thermal polymerization initiator or a photopolymerization initiator may be used depending on the polymerization method.
Examples of the thermal polymerization initiator include an azo compound-based polymerization initiator, an organic peroxide-based polymerization initiator, and an inorganic peroxide-based polymerization initiator, and the azo compound-based polymerization initiator and the organic peroxide-based polymerization initiator are preferred, and the organic peroxide-based polymerization initiator is more preferred. Examples of the photopolymerization initiator include an acetophenone-based polymerization initiator, a benzophenone-based polymerization initiator, an alkylphenone-based polymerization initiator, a thioxanthone-based polymerization initiator, a xanthone-based photopolymerization initiator, an acylphosphine-based polymerization initiator, an oxime-based polymerization initiator, a benzoin compound-based polymerization initiator, an anthracene compound-based polymerization initiator, and a quinone compound-based polymerization initiator, and the acetophenone-based polymerization initiator, a benzophenone-based polymerization initiator, a thioxanthone-based polymerization initiator, and an acylphosphine-based polymerization initiator are preferred. Examples of the thermal and photopolymerization initiator include an azo compound-based polymerization initiator and an organic peroxide.
These polymerization initiators can be used alone or in combination of two or more. For example, a combination of an acetophenone-based photopolymerization initiator and a benzophenone-based photopolymerization initiator, and a combination of an acetophenone-based photopolymerization initiator and a thioxanthone-based photopolymerization initiator are preferred.

Examples of azo compound-based thermal polymerization initiators include 2,2-azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylbutyronitrile) (AMBN), azobiscyanovaleric acid, 2,2'-azobis(4-methoxy-2.4-dimethylvaleronitrile), 2,2'-azobis(2.4-dimethylvaleronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis[2-(2-imidazoline-2-isopropyl] 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane]disulfate dihydrate, 2,2'-azobis(2-methylpropionamidine)dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane)dihydrochloride, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], etc., which may be used alone or in combination of two or more. Among them, 2,2-azobisisobutyronitrile (AIBN) is preferred.

Examples of the organic peroxide polymerization initiator include organic peroxides such as tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, benzoyl peroxide, and tert-butyl hydroperoxide. These may be used alone or in combination of two or more.
Examples of inorganic peroxide-based polymerization initiators include inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate, which may be used alone or in combination of two or more. Among these, benzoyl peroxide is preferred.

Examples of acetophenone-based photopolymerization initiators include α-aminoacetophenone-based photopolymerization initiators such as 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, as well as 1-hydroxy-cyclohexyl-phenyl-ketone. Examples of photopolymerization initiators include α-hydroxyacetophenone-based initiators such as 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl]-2-methyl-propan-1-one, and 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl]-2-methyl-propan-1-one, which may be used alone or in combination of two or more. Among these, α-hydroxyacetophenone-based photopolymerization initiators are preferred.

Benzophenone-based polymerization initiators include, for example, benzophenone, 4-methylbenzophenone, o-benzoylbenzoic acid methyl-4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylated benzophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 2,4-dihydro Examples of the benzophenone include 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-propoxybenzophenone, benzophenone, o-benzoylmethylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, and 4,4'-di(N,N'-dimethylamino)-benzophenone. These may be used alone or in combination of two or more. Of these, benzophenone is preferred.

Examples of alkylphenone compound-based polymerization initiators include benzyl methyl ketal compounds such as 2,2'-dimethoxy-1,2-diphenylethane-1-one, α-hydroxyalkylphenone compounds such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one, and aminoalkylphenone compounds such as 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one and 2-benzylmethyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, which may be used alone or in combination of two or more.

Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, dimethylthioxanthone (e.g., 2,4-dimethylthioxanthone), diethylthioxanthone (e.g., 2,4-diethylthioxanthone), isopropylthioxanthone (e.g., 2-isopropylthioxanthone), chlorothioxanthone (e.g., 2,4-dichlorothioxanthone 9, mercaptothioxanthone, and the like.
Examples of the xanthone-based photopolymerization initiator include xanthone, 2-isopropylxanthone, 2,4-dimethylxanthone, 2,4-diethylxanthone, and 2,4-dichloroxanthone. These may be used alone or in combination of two or more kinds.

Examples of acylphosphine-based photopolymerization initiators include bisacylphosphine oxide-based photopolymerization initiators and monoacylphosphine oxide-based photopolymerization initiators. Specific examples include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. phosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl-2,4,6-trimethylbenzoylphenylphosphinate, (2,6-dimethoxybenzoyl)-2,4,4-pentylphosphine oxide, etc., which may be used alone or in combination of two or more. In particular, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is preferred.

Examples of O-acyloxime compound-based photopolymerization initiators include N-benzoyloxy-1-(4-phenylsulfanylphenyl)butan-1-one-2-imine, N-benzoyloxy-1-(4-phenylsulfanylphenyl)octan-1-one-2-imine, N-benzoyloxy-1-(4-phenylsulfanylphenyl)-3-cyclopentylpropan-1-one-2-imine, N-acetoxy-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethane-1-imine, and N-acetoxy-1-[9-ethyl-6-{2-methyl-4-(3,3-dimethyl-2,4-dioxacyclopentanylmethyloxy)benzoyl}-9H-carbazole. -3-yl]ethane-1-imine, N-acetoxy-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-3-cyclopentylpropan-1-imine, N-benzoyloxy-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-3-cyclopentylpropan-1-one-2-imine, N-acetyloxy-1-[4-(2-hydroxyethyloxy)phenylsulfanylphenyl]propan-1-one-2-imine, N-acetyloxy-1-[4-(1-methyl-2-methoxyethoxy)-2-methylphenyl]-1-(9-ethyl-6-nitro-9H-carbazol-3-yl)methane-1-imine, etc.

Examples of benzoin compound-based polymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of anthracene compound-based polymerization initiators include 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 2-ethyl-9,10-diethoxyanthracene. Examples of quinone compound-based polymerization initiators include 9,10-phenanthrenequinone, 2-ethylanthraquinone, and camphorquinone.

The content of the polymerization initiator is preferably 0.01 to 10 parts by mass per 100 parts by mass of the total of the (A) and (B) components. The content of the polymerization initiator is more preferably 2 to 8 parts by mass. When multiple polymerization initiators are combined, the total content should be in the above-mentioned mass ratio. For example, in a combination of an acetophenone-based photopolymerization initiator and a benzophenone-based photopolymerization initiator, or a combination of an acetophenone-based photopolymerization initiator and a thioxanthone-based photopolymerization initiator, the mass ratio of the acetophenone-based photopolymerization initiator to the benzophenone-based photopolymerization initiator or the thioxanthone-based photopolymerization initiator is preferably 3:1 to 1:2, and more preferably 2:1 to 1:1.

There are no particular limitations on the UV absorber, but examples include benzotriazole-based UV absorbers, triazine-based UV absorbers, and cyanoacrylate-based UV absorbers, which may be used alone or in combination of two or more.

Benzotriazole-based ultraviolet absorbers include, for example, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)benzotriazole, 2-(3,5-di-t-pentyl-2-hydroxyphenyl-2-benzotriazole, 2-(2-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidylmethyl)phenol, 2-(2-hydroxy-4-octyloxy)phenyl 2-(2-hydroxy-5-t-octylphenyl)-2-benzotriazole, 2-(2-hydroxy-5-methyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2-hydroxy-5-t-butylphenyl)benzotriazole, 2-(2-hydroxy-3-t-butyl-5-methylphenyl)benzotriazole, 2-(2-hydroxy-3,5-t-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-t-butylphenyl)benzotriazole, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2-hydroxy-3,5-t-pentylbenzotriazole, 2-[2-hydroxy-5-(1,1,3,3,-tetramethylbutyl)]benzotriazole, 2-(2-hydroxy-3-s-butyl-5-t-butylbenzotriazole, 2-(2-hydroxy Examples include 3-dodecyl-5-methylbenzotriazole, 2-(2-hydroxy-3-t-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2,2-methylenebis[4-(1,1,3,3-tetramethylbutyl)]-6-(2H-benzotriazol-2-yl)phenol], and 3-[3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl]propionate.

Examples of triazine-based ultraviolet absorbers include 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine.

Examples of cyanoacrylate-based ultraviolet absorbers include 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate and ethyl-2-cyano-3,3'-diphenylacrylate.

The ultraviolet absorber is preferably contained in the curable resin composition in a range of 0 to 2.0% by mass, and more preferably in a range of 0.1 to 1.0% by mass. The ultraviolet absorber is preferably contained in a total range of 0 to 20 parts by mass, more preferably in a range of 5 to 16 parts by mass, and more preferably in a range of 8 to 14 parts by mass, per 100 parts by mass of the urethane (meth)acrylate (A) and the alkylene oxide-modified (meth)acrylate (B).

There are no particular limitations on the light stabilizer, but examples include hindered amine light stabilizers.

Examples of hindered amine light stabilizers include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-methoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-ethoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-propoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-butoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, and bis(1-pentyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate. bis(1-hexyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-heptyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-nonyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-decanyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-dodecyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(4-methyl tetrakis(2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate; aminomethyl group-containing compounds such as tetrakis(2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate; condensation products of 1,2,3,4-butane tetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol, and β,β,β,β-tetramethyl-3,9-(2,4,8,10-tetraoxaspiro[5,5])undecane)diethanol; Examples of amino ether group-containing compounds include a condensation product of piperidinol and β,β,β,β-tetramethyl-3,9-(2,4,8,10-tetraoxaspiro[5,5])undecane)diethanol, a reaction product of a diester compound of decanedicarboxylic acid and 2,2,6,6-tetramethyl-1-octoxy-4-piperidinol with 1,1-dimethylethyl hydroperoxide and octane (manufactured by BASF, product name Tinuvin 123), and bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1,dimethylethyl)-4-hydroxyphenyl]methyl] (manufactured by BASF, product name Tinuvin 144).

The light stabilizer is preferably contained in the curable resin composition in an amount ranging from 0 to 0.3% by mass, more preferably in an amount ranging from 0.05 to 0.2% by mass. The light stabilizer is preferably contained in a total amount ranging from 0 to 2.5 parts by mass, more preferably in an amount ranging from 0.6 to 2 parts by mass, and more preferably in an amount ranging from 1 to 1.8 parts by mass, relative to a total of 100 parts by mass of the urethane (meth)acrylate (A) and the alkylene oxide-modified (meth)acrylate (B). It is also preferable to combine the light stabilizer with the above-mentioned ultraviolet absorber, and in this case, the mass ratio of the ultraviolet absorber to the stabilizer (ultraviolet absorber:stabilizer) is preferably in the range of 1:2 to 30:1, more preferably in the range of 1:1 to 14:1.

As the leveling agent, for example, polydimethylsiloxane, its copolymer, acrylic polymer having polydimethylsiloxane skeleton, urethane polymer having polydimethylsiloxane skeleton, and silicone-based leveling agent such as compound having active energy ray reactivity introduced with acryloyl group or methacryloyl group, or fluorine-based leveling agent such as perfluoroalkylsulfonic acid, perfluoroalkylcarboxylic acid, fluorotelomer alcohol or derivative thereof can be mentioned. As a commercially available product, for example, Futergent 602A manufactured by Neos Corporation can be mentioned.
The leveling agent is contained in the coating agent of the present invention in an amount of preferably 0 to 0.5% by mass, and more preferably 0.01 to 0.3% by mass.

Examples of the antioxidant include di-t-butylhydroxytoluene, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], pionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, octylated diphenylamine, 2,4,-bis[(octylthio)methyl]-O-cresol, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, dibutylhydroxytoluene, and the like.
The antioxidant is preferably contained in the coating agent of the present invention in an amount of 0 to 2% by mass.

Examples of thickeners include association-type nonionic urethane thickeners, alkali swelling thickeners, bentonite which is an inorganic intercalation compound, cellulose-based thickeners, (meth)acrylic acid-based thickeners, polyurethane-based thickeners, polyacrylamide-based thickeners, vinyl ether-based thickeners, mineral-based thickeners, and polysaccharide-based thickeners.
The thickener is preferably contained in the curable resin composition of the present invention in an amount of 0 to 5% by mass.

Examples of the plasticizer include phthalate esters, non-aromatic dibasic acid esters, aliphatic esters, esters of polyalkylene glycols, phosphate esters, trimellitic acid esters, chlorinated paraffins, hydrocarbon oils, process oils, polyethers, epoxy plasticizers, polyester plasticizers, etc., and preferably phthalate esters. Specific examples of the plasticizer include dibutyl phthalate, diheptyl phthalate, di(2-ethylhexyl)phthalate, dioctyl phthalate, dioctyl adipate, dioctyl sebacate, dibutyl sebacate, isodecyl succinate, tricresyl phosphate, tributyl phosphate, epoxidized soybean oil, and epoxy benzyl stearate.
The plasticizer is preferably contained in the curable resin composition of the present invention in an amount of 0 to 10% by mass.

Examples of the lubricant include hydrocarbon-based, fatty acid-based, higher alcohol-based, aliphatic amide-based, metal soap-based, ester-based, amide-based lubricants, silicone compounds, and perfluoroalkyl compounds.
The lubricant is preferably contained in the curable resin composition of the present invention in an amount of 0 to 1% by mass.

Examples of colorants include dyes such as direct dyes, acid dyes, basic dyes, and metal complex dyes; inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide, and mica; and organic pigments such as coupling azo pigments, condensed azo pigments, anthraquinone pigments, thioindigo pigments, dioxazone pigments, and phthalocyanine pigments.
The colorant is preferably contained in the curable resin composition of the present invention in an amount of 0 to 2% by mass.

Examples of flame retardants include additive and reactive flame retardants such as phosphorus- and halogen-containing organic compounds, bromine- or chlorine-containing organic compounds, ammonium polyphosphate, aluminum hydroxide, and antimony oxide.
The flame retardant is preferably contained in the curable resin composition of the present invention in an amount of 0 to 20% by mass.

Examples of the antistatic agent include cationic antistatic agents of quaternary ammonium salts, aliphatic sulfonates, higher alcohol sulfates, higher alcohol alkylene oxide adduct sulfates, higher alcohol phosphates, and higher alcohol alkylene oxide adduct phosphate salts, higher alcohol alkylene oxide adducts, and polyalkylene glycol fatty acid esters.
The antistatic agent is preferably contained in the curable resin composition of the present invention in an amount of 0 to 5% by mass.

Examples of organic particles include particles formed from polyacrylate resins, polymethacrylate resins, polyolefin resins, polystyrene resins, polyamide resins, polyamino acid resins, polyester resins, polyurethane resins, polyvinyl chloride resins, cellulose resins, melamine resins, urea resins, epoxy resins, fluororesins, and mixtures thereof.
The organic particles are preferably contained in the curable resin composition of the present invention in an amount of 0 to 30% by mass.

The coating agent of the present invention usually contains the above-mentioned components in a polymerization solvent.
The polymerization solvent is not particularly limited as long as it can dissolve each monomer to be polymerized, the polymer precursor to be produced, and, if necessary, a polymerization initiator and other additives, and examples of the polymerization solvent that can be used include methanol, ethanol, isopropanol, tetrahydrofuran, cyclohexanone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, toluene, ethyl acetate, ethyl lactate, methyl lactate, dimethyl sulfoxide, and water. These may be used alone or in combination of two or more. 1-Methoxy-2-propanol (PGM) is preferred because it has moderate solubility and does not easily dissolve substrates such as polycarbonate.

The content of the polymerization solvent in the curable composition is not particularly limited, but usually, 10% by mass to 80% by mass of the polymerization solvent can be blended in the curable composition, and in many cases, 30% by mass to 70% by mass of the polymerization solvent, preferably 30% by mass to 60% by mass of the polymerization solvent is blended in the curable composition.
The amount is usually 10 to 500 parts by mass, and preferably 50 to 300 parts by mass, per 100 parts by mass of the organic coating component. The viscosity of the coating agent is usually 5 to 500 mPa·s, and preferably 10 to 100 mPa·s, at the temperature during use (usually 15 to 30° C.).
The coating agent may be diluted with a solvent to adjust the viscosity to an appropriate level when applied. The content of the solvent after dilution is usually 55 to 85% by mass, and preferably 70 to 80% by mass, in the coating agent.

The curable composition can be applied to a substrate, and a cured product can be formed on the entire surface, one surface, or a portion of an inorganic or organic substrate by, for example, applying active energy rays to the curable composition or by heating the composition. For curing, both irradiation with active energy rays and heating may be performed.

The curable composition can be applied to the substrate by, for example, a bar coater, applicator, die coater, spin coater, spray coater, curtain coater, roll coater, screen printing, dipping, etc.

The amount of the curable composition applied to the substrate is not particularly limited and may be adjusted according to the thickness of the cured layer to be formed. As a guideline, the amount is preferably such that the thickness of the cured layer obtained after the curing treatment by irradiation with active energy rays and/or heating is 1 to 1,000 μm, and more preferably 10 to 800 μm.

The active energy rays are not particularly limited, and examples thereof include ultraviolet rays and electron beams.
When irradiating with ultraviolet rays, an ultraviolet irradiator equipped with a light source such as a high-pressure mercury lamp or a metal halide lamp can be used. The irradiation amount of ultraviolet rays is preferably 30 to 2,000 mW/ ^cm2 in illuminance and 100 to 1,000 mJ/ ^cm2 in cumulative light amount. The curing atmosphere may be either an air atmosphere or an inert gas (e.g., nitrogen, argon) atmosphere. When irradiating with electron beams, a commercially available electron beam irradiator can be used, and the irradiation amount of electron beams is preferably 1 to 10 Mrad.

After curing by irradiation with active energy rays, a heat treatment (annealing treatment) may be performed as necessary to further promote curing. The heating temperature is preferably in the range of 80 to 220°C. The heating time is preferably in the range of 10 to 60 minutes.

When the curable composition is cured by thermal polymerization, the heating temperature is preferably in the range of 80 to 200° C., and more preferably in the range of 100 to 150° C. If the heating temperature is lower than 80° C., the heating time needs to be extended, which tends to be uneconomical, whereas if the heating temperature is higher than 200° C., the energy costs are high and the heating time and the temperature drop time are long, which tends to be uneconomical.
The polymerization conditions are not particularly limited and can be appropriately adjusted depending on the type of polymerization initiator used, etc., but the reaction can be carried out, for example, in an inert gas (preferably nitrogen) atmosphere at a polymerization temperature of 60 to 90° C. for 3 to 10 hours.

The cured resin composition can be used for various substrates, such as polycarbonate, polymethyl methacrylate, polystyrene, polyester, polyolefin, polycycloolefin, polyimide, epoxy resin, melamine resin, triacetyl cellulose resin, ABS resin, AS resin, and norbornene resin.

The thickness of the cured layer formed can be adjusted by the amount of coating, as described above, and is usually less than 15 μm, preferably 10 μm or less, and more preferably 7 μm or less.

The resulting cured product has excellent transparency, heat resistance, and moist heat resistance, making it suitable for use as a coating material for outdoor displays such as digital signage, automotive resin substrates, etc.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, all parts and percentages in each example are by weight, and all room temperature storage conditions are 23°C/55% RH.

1. Production of urethane (meth)acrylate (A) [Synthesis Example 1]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc., 169.4 g of hexamethylene diisocyanate (HDI manufactured by Tosoh Corporation, isocyanate amount 50%), pentaerythritol acrylate having a hydroxyl value of 115 mgKOH/g (PEA, Aronix M-305 manufactured by Toagosei Co., Ltd., the content of pentaerythritol diacrylate is 0%, the content of pentaerythritol monoacrylate is 0%, and the content of pentaerythritol triacrylate is 0%. A mixture of 1,428.7 g of urethane acrylate (containing 60% isocyanate and 40% pentaerythritol tetraacrylate), 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst was added and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-1.
The obtained urethane acrylate A-1 had a solid content of 80%, a viscosity at 25° C. of about 100 mPa·S, and a hydroxyl value calculated based on the solid content of 29.2 mgKOH/g.

[Synthesis Example 2]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc., 249.3 g of dicyclohexylmethane 4,4-diisocyanate (H12MDI, VESTANT (registered trademark) manufactured by Evonik Corporation), 100 g of pentaerythritol acrylate having a hydroxyl value of 115 mgKOH/g (PEA, ARONIX M-305 manufactured by Toagosei Co., Ltd., the content of pentaerythritol diacrylate is 0%, the content of pentaerythritol monoacrylate is 0%, and the content of pentaerythritol A mixture of 1,348.8 g of urethane acrylate (containing 60% pentaerythritol triacrylate and 40% pentaerythritol tetraacrylate), 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst was added and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-2.
The obtained urethane acrylate A-2 had a solid content of 80%, a viscosity of about 80 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 27.3 mgKOH/g.

[Synthesis Example 3]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc., 568.9 g of dicyclohexylmethane 4,4-diisocyanate (H12MDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 32%), pentaerythritol acrylate having a hydroxyl value of 280 mgKOH/g (Aronix M-933, manufactured by Toagosei Co., Ltd., pentaerythritol diacrylate content 30%, pentaerythritol monoacrylate content 5%, pentaerythritol acrylate content 10%, and pentaerythritol acrylate content 10% were added. 1,029.2 g of a mixture containing 50% erythritol triacrylate and 15% pentaerythritol tetraacrylate, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, Nitto Kasei Co., Ltd.) as a reaction catalyst were charged and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-3.
The obtained urethane acrylate A-3 had a solids content of 80%, a viscosity of about 350 mPa·S at 25° C., and a hydroxyl value calculated based on the solids content of 28.5 mgKOH/g.

[Synthesis Example 4]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like, 217.3 g of isophorone diisocyanate (IPDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 37.7%), pentaerythritol acrylate (PEA, ARONIX M-305 manufactured by Toagosei Co., Ltd., with a hydroxyl value of 115 mgKOH/g, pentaerythritol diacrylate content of 0%, pentaerythritol monoacrylate content of 0%, and pentaerythritol A mixture of 1,380.7 g of urethane acrylate (containing 60% pentaerythritol triacrylate and 40% pentaerythritol tetraacrylate), 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst was added and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-4.
The obtained urethane acrylate A-4 had a solid content of 80%, a viscosity of about 110 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 27.6 mgKOH/g.

[Synthesis Example 5]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like, 511.4 g of isophorone diisocyanate (IPDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 37.7%), pentaerythritol acrylate having a hydroxyl value of 280 mgKOH/g (Aronix M-933, manufactured by Toagosei Co., Ltd., pentaerythritol diacrylate content 30%, pentaerythritol monoacrylate content 5%, pentaerythritol acrylate content 5%, and pentaerythritol acrylate content 5% were added. A mixture of 1,086.7 g of urethane acrylate (containing 50% pentaerythritol triacrylate and 15% pentaerythritol tetraacrylate), 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst was added and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-5.
The obtained urethane acrylate A-5 had a solid content of 80%, a viscosity of about 400 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 40.8 mgKOH/g.

[Synthesis Example 6]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like, 127.8 g of isophorone diisocyanate (IPDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 37.7%), 1470.2 g of dipentaerythritol acrylate (DPHA, Aronix M-403 manufactured by Toa Gosei Co., Ltd.) having a hydroxyl value of 95 mg KOH/g, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600 manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst were charged, and the mixture was reacted at 70° C. with uniform stirring, and the reaction was terminated when the remaining isocyanate groups reached 0.1%, thereby obtaining urethane acrylate A-6.
The obtained urethane acrylate A-6 had a solid content of 80%, a viscosity of about 110 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 13.7 mgKOH/g.

[Synthesis Example 7]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like, 321.2 g of dicyclohexylmethane 4,4-diisocyanate (H12MDI, VESTANT (registered trademark) manufactured by Evonik Corporation, isocyanate amount 32%), pentaerythritol acrylate having a hydroxyl value of 115 mgKOH/g (PEA, ARONIX M-305 manufactured by Toagosei Co., Ltd., the content of pentaerythritol diacrylate is 0%, the content of pentaerythritol monoacrylate is 0%, and the content of pentaerythritol diacrylate is 0%. 1,276.9 g of a mixture containing 60% erythritol triacrylate and 40% pentaerythritol tetraacrylate, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst were charged and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-7.
The obtained urethane acrylate A-7 had a solids content of 80%, a viscosity of about 140 mPa·S at 25° C., and a hydroxyl value calculated based on the solids content of 5.2 mgKOH/g.

[Synthesis Example 8]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc., 615.3 g of dicyclohexylmethane 4,4-diisocyanate (H12MDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 32%), pentaerythritol acrylate (PEA, ARONIX M-933 manufactured by Toagosei Co., Ltd., pentaerythritol diacrylate content 30%, pentaerythritol monoacrylate content 5%, pentaerythritol diacrylate content 5 ... 982.8 g of a mixture containing 50% taerythritol triacrylate and 15% pentaerythritol tetraacrylate, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst were charged and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-8.
The obtained urethane acrylate A-8 had a solid content of 80%, a viscosity of about 500 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 6.7 mgKOH/g.

[Comparative Synthesis Example 1]
A reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like was charged with 595.5 g of dicyclohexylmethane 4,4-diisocyanate (H12MDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 32%), 738.7 g of polytetramethylene ether glycol (PTMEG, PTMG650 manufactured by Mitsubishi Chemical Corporation, molecular weight 650), 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600 manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst, and the mixture was reacted for 2 hours with uniform stirring at 70°C. Thereafter, 263.9 g of 2-hydroxyethyl acrylate (2HEA, manufactured by Osaka Organic Industry Co., Ltd., hydroxyl value 483 mgKOH/g) was added and reacted for 3 hours. The reaction was terminated when the residual isocyanate group reached 0.1%, thereby obtaining urethane acrylate A-9.
The obtained urethane acrylate A-9 had a solid content of 80%, a viscosity of about 2000 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 15 mgKOH/g. Note that urethane acrylate A-9 is the urethane acrylate used in the examples of Japanese Patent No. 4204106.

[Comparative Synthesis Example 2]
In a reaction vessel equipped with a thermometer, reflux condenser, stirrer, dropping funnel, etc., 645.6 g of bifunctional hexamethylene diisocyanate-based prepolymer (HDI-based prepolymer, Asahi Kasei Corporation's Duranate A201H, isocyanate amount 15.8%), 952.5 g of lactone-modified acrylate (LA, Daicel Corporation's Plaxel FA2D) with a hydroxyl value of 163 mg KOH/g, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Nitto Kasei Corporation's Neostan U-600) as a reaction catalyst were charged and reacted at 70 ° C. with uniform stirring. The reaction was terminated when the residual isocyanate group reached 0.1%, and urethane acrylate A-10 was obtained.
The obtained urethane acrylate A-10 had a solid content of 80%, a viscosity of about 1200 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 11.3 mgKOH/g. The urethane acrylate A-10 is the urethane acrylate used in the examples of Japanese Patent No. 7452588.

[Comparative Synthesis Example 3]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc., 210.9 g of norbornene diisocyanate (synthesized by Taisei Fine Chemical Co., Ltd., isocyanate amount 47.1%), pentaerythritol acrylate (PEA, Aronix M-305 manufactured by Toa Gosei Co., Ltd., with a hydroxyl value of 115 mg KOH/g, pentaerythritol diacrylate content 0%, pentaerythritol monoacrylate content 0%, pentaerythritol triacrylate content 0%, A mixture of 1,387.1 g of urethane acrylate (containing 60% acrylate and 40% pentaerythritol tetraacrylate), 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600, manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst was added and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-11.
The obtained urethane acrylate A-11 had a solid content of 80%, a viscosity of about 110 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 15.3 mgKOH/g. The urethane acrylate A-11 is the urethane acrylate used in the examples of Japanese Patent No. 6,481,302.

[Comparative Synthesis Example 4]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like, 303.6 g of 1,3,bis(isocyanatomethyl)cyclohexane (H6XDI, Takenate (registered trademark) 600 manufactured by Mitsui Chemicals, Inc., isocyanate amount 43.3%), pentaerythritol acrylate having a hydroxyl value of 280 mgKOH/g (PEA, Aronix M-933 manufactured by Toagosei Co., Ltd., the content of pentaerythritol diacrylate is 30%, the content of pentaerythritol monoacrylate is 5%, the content of pentaerythritol triacrylate is 50%, and the content of pentaerythritol triacrylate is 50%. A mixture containing 567.3 g of dipentaerythritol tetraacrylate (15% by weight), 727.1 g of dipentaerythritol acrylate (DPHA, Aronix M-403 manufactured by Toagosei Co., Ltd.) having a hydroxyl value of 95 mgKOH/g, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600 manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst was added and reacted at 70°C with uniform stirring. The reaction was terminated when the remaining isocyanate groups reached 0.1%, yielding urethane acrylate A-12.
The obtained urethane acrylate A-12 had a solid content of 80%, a viscosity of about 400 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 16.4 mgKOH/g. The urethane acrylate A-12 is the urethane acrylate used in the examples of Japanese Patent No. 7024558.

[Comparative Synthesis Example 5]
Into a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like, 535.4 g of dicyclohexylmethane 4,4-diisocyanate (H12MDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 32%), 1062.7 g of pentaerythritol acrylate (Aronix M-926 manufactured by Toagosei Co., Ltd.) having a hydroxyl value of 310 mgKOH/g, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600 manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst were charged, and the mixture was reacted at 70°C with uniform stirring, and the reaction was terminated when the remaining isocyanate groups reached 0.1%, to obtain urethane acrylate A-13.
The obtained urethane acrylate A-13 had a solid content of 80%, a viscosity of about 4,800 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 64.2 mgKOH/g.

[Comparative Synthesis Example 6]
In a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, and the like, 127.8 g of dicyclohexylmethane 4,4-diisocyanate (H12MDI, VESTANT (registered trademark) manufactured by Evonik, isocyanate amount 32%), 1470.2 g of dipentaerythritol acrylate (DPHA, NK Ester A-9550 manufactured by Shin-Nakamura Chemical Co., Ltd.) having a hydroxyl value of 50 mgKOH/g, 399.5 g of methyl ethyl ketone as a solvent, 0.8 g of methoquinone as a polymerization inhibitor, and 1.6 g of inorganic bismuth (Neostan U-600 manufactured by Nitto Kasei Co., Ltd.) as a reaction catalyst were charged, and the mixture was reacted at 70°C with uniform stirring, and the reaction was terminated when the remaining isocyanate groups reached 0.1%, to obtain urethane acrylate A-14.
The obtained urethane acrylate A-14 had a solid content of 80%, a viscosity of about 110 mPa·S at 25° C., and a hydroxyl value calculated based on the solid content of 13.7 mgKOH/g.

The synthesis conditions for each urethane acrylate and the hydroxyl value of each obtained urethane acrylate are outlined below.


UA: urethane acrylate PEA: pentaerythritol acrylate DPHA: dipentaerythritol acrylate HDI: hexamethylene diisocyanate H12MDI: dicyclohexylmethane diisocyanate H6XDI: 1,3, bis(isocyanatomethyl)cyclohexane IPDI: isophorone diisocyanate LA: lactone modified acrylate HEA: 2-hydroxyethyl acrylate NBDI: norbornene diisocyanate SEA: sorbitol EO modified acrylate OH value 50 mg KOH/g DPHA: NK Ester A-9550 manufactured by Shin-Nakamura Chemical Co., Ltd.
OH value 95 mg KOH/g DPHA: Aronix M-403 manufactured by Toagosei Co., Ltd.
OH value 115 mg KOH/g PEA: Aronix M-305 manufactured by Toagosei Co., Ltd.
OH value 280 mg KOH/g PEA: Aronix M-933 manufactured by Toagosei Co., Ltd.
OH value 310 mg KOH/g SEA: Aronix M-926 manufactured by Toagosei Co., Ltd.
PTMEG: Polytetramethylene ether glycol (PTMG650, molecular weight 650, manufactured by Mitsubishi Chemical Corporation)
OH value 163 mg KOH/g LA: Plaxel FA2D manufactured by Daicel Corporation
OH value 483 mg KOH/g HEA: 2-hydroxyethyl acrylate manufactured by Osaka Organic Industry Co., Ltd., hydroxyl value 483 mg KOH/g
HDI (NCO%: 50%): HDI (isocyanate content 50%) manufactured by Tosoh Corporation
H12MDI (NCO%: 32): VESTANAT (registered trademark) manufactured by Evonik (isocyanate content 32%)
IPDI (NCO%: 37.7): VESTANAT (registered trademark) manufactured by Evonik (isocyanate content: 37.7%)
H6XDI (NCO%: 43.8): Takenate (registered trademark) 600 (isocyanate content 43.8%) manufactured by Mitsui Chemicals, Inc.
Bifunctional HDI (NCO%: 15.8): Bifunctional hexamethylene diisocyanate (HDI) prepolymer (Duranate A-201H, manufactured by Asahi Kasei Corporation)
NBDI (NCO%: 47.1): Taisei Fine Co., Ltd. synthesis (isocyanate content 47.1%)

2. Preparation of alkylene oxide-modified or unmodified (meth)acrylate (B) [Synthesis Example 9]
A reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc. was charged with 134 g of trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight 134.2), 0.3 g of caustic potassium, and 134 g of toluene as a solvent. While stirring uniformly at 140°C, 44 g of ethylene oxide (molecular weight 44) was gradually blown into the reaction vessel to cause a reaction. After the reaction, the mixture was neutralized with acetic acid to obtain ethylene oxide-modified trimethylolpropane.
178 g of the obtained ethylene oxide-modified trimethylolpropane, 216 g of acrylic acid, 30 g of paratoluenesulfonic acid, 0.45 g of hydroquinone, and 400 g of toluene as a solvent were charged into another reaction vessel, and the vessel was heated to 110° C. while blowing in air to carry out a reaction. Water generated by the dehydration reaction was removed as needed during the reaction. After the reaction, the vessel was washed with an alkali and washed with water, and toluene was recovered under reduced pressure while blowing in air to obtain ethylene oxide-modified trimethylolpropane triacrylate B-1.
The resulting B-1 was analyzed by ¹ H-NMR, ¹³ C-NMR, and HPLC under the following conditions, and the number of ethylene oxide added was found to be 0.9.

¹ H-HMR analysis conditions Apparatus: JEOL ECX-400
Measurement solvent: deuterated chloroform Measurement concentration: 1% by weight
Measurement temperature 50℃
Accumulation count: 16

^13C -NMR analysis conditions Apparatus: JEOL ECX-400
Measurement solvent: deuterated chloroform Measurement concentration: 5% by weight
Measurement temperature: Room temperature Accumulation count: 4096 times

HPLC analysis conditions
Equipment : SHIMADZU LC-10A
Detector: UV 254 nm
Column: GL Science Inertsil ODS-2 (4.6 x 150 mm)
Column temperature: 40°C
Eluent: acetonitrile/0.1% phosphoric acid = 60/40
Flow rate: 0.6 ml/min Sample injection volume: 2 μl
Sample concentration: 1 wt%

[Synthesis Example 10]
A reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc. was charged with 134 g of trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight 134.2), 0.3 g of caustic potassium, and 134 g of toluene as a solvent. While stirring uniformly at 140°C, 176 g of ethylene oxide (molecular weight 44) was gradually blown into the reaction vessel to cause a reaction. After the reaction, the mixture was neutralized with acetic acid to obtain ethylene oxide-modified trimethylolpropane.
310 g of the obtained ethylene oxide-modified trimethylolpropane, 216 g of acrylic acid, 30 g of paratoluenesulfonic acid, 0.45 g of hydroquinone, and 600 g of toluene as a solvent were charged into another reaction vessel, and the vessel was heated to 110° C. while blowing in air to carry out a reaction. Water generated by the dehydration reaction was removed as needed during the reaction. After the reaction, the vessel was washed with an alkali and washed with water, and the toluene was recovered under reduced pressure while blowing in air to obtain ethylene oxide-modified trimethylolpropane triacrylate B-2.
The resulting B-2 was analyzed by ¹ H-NMR, ¹³ C-NMR, and HPLC under the above-mentioned conditions, and the number of ethylene oxide added was found to be 3.7.

[Synthesis Example 11]
A reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc. was charged with 134 g of trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight 134.2), 0.3 g of caustic potassium, and 134 g of toluene as a solvent. While stirring uniformly at 140°C, 308 g of ethylene oxide (molecular weight 44) was gradually blown into the reaction vessel to cause a reaction. After the reaction, the mixture was neutralized with acetic acid to obtain ethylene oxide-modified trimethylolpropane.
442 g of the obtained ethylene oxide-modified trimethylolpropane, 216 g of acrylic acid, 30 g of paratoluenesulfonic acid, 0.45 g of hydroquinone, and 800 g of toluene as a solvent were charged into another reaction vessel, and the vessel was heated to 110° C. while blowing in air to carry out a reaction. Water generated by the dehydration reaction was removed as needed during the reaction. After the reaction, the vessel was washed with an alkali and washed with water, and the toluene was recovered under reduced pressure while blowing in air to obtain ethylene oxide-modified trimethylolpropane triacrylate B-3.
The resulting B-3 was analyzed by ¹ H-NMR, ¹³ C-NMR and HPLC, and the addition number of ethylene oxide was found to be 6.4.

[Synthesis Example 12]
In a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel, etc., 178 g of trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight 134.2), 216 g of acrylic acid, 30 g of paratoluenesulfonic acid, 0.45 g of hydroquinone, and 400 g of toluene as a solvent were charged, and the reaction was carried out by heating to 110 ° C. while blowing in air. Water generated by the dehydration reaction was removed as needed during the reaction. After the reaction, alkali washing and water washing were carried out, and toluene was recovered under reduced pressure while blowing in air, to obtain ethylene oxide non-modified trimethylolpropane triacrylate B-4.
The number of ethylene oxide addition units in the obtained B-4 is 0.

The number (mol) of ethylene oxide added in the resulting ethylene oxide modified trimethylolpropane triacrylates B-1 to B-3 is shown below.

EO modified TMPTA: Ethylene oxide modified trimethylolpropane triacrylate

3. Preparation of curable resin composition [Example 1]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g), 10 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide added is 0.9), and 10 g of ethylene oxide-modified trimethylolpropane triacrylate B-2 (ethylene oxide 25 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide additions: 3.7), 5 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide additions: 6.4), 8 g of benzotriazole based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of monoacylphosphine oxide based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator were mixed and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added as a diluent to prepare a curable composition with a solid content of 50.0%.

[Example 2]
80 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g), 5 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), and 5 g of ethylene oxide-modified trimethylolpropane triacrylate B-2 (the number of ethylene oxide units added is 0.9) were mixed. A curable composition having a solid content of 50.0% was prepared by mixing and stirring 12.5 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (addition number 3.7), 2.5 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (addition number of ethylene oxide 6.4), 8 g of a benzotriazole ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of a hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of a monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator, and adding 114 g of 1-methoxy-2-propanol (PGM).

[Example 3]
20 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g), 20 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), and 20 g of ethylene oxide-modified trimethylolpropane triacrylate B-2 (ethylene oxide A curable composition having a solid content of 50.0% was prepared by mixing and stirring 50 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 3.7), 10 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 6.4), 8 g of a benzotriazole ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of a hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of a monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator, and adding 114 g of 1-methoxy-2-propanol (PGM).
.

[Example 4]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g), 18 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), and 18 g of ethylene oxide-modified trimethylolpropane triacrylate B-2 (ethylene oxide A curable composition having a solid content of 50.0% was prepared by mixing and stirring 12 g of ethylene oxide-modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 3.7), 10 g of ethylene oxide-modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 6.4), 8 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of a hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of a monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator, and adding 114 g of 1-methoxy-2-propanol (PGM).

[Example 5]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g), 4 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), and 1 g of ethylene oxide-modified trimethylolpropane triacrylate B-2 (the number of ethylene oxide units added is 0.9) were mixed. 32 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 3.7), 4 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 6.4), 8 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of a hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of a monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator were mixed and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Example 6]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g), 4 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), and 1 g of ethylene oxide-modified trimethylolpropane triacrylate B-2 (the number of ethylene oxide units added is 0.9) were mixed. A curable composition having a solid content of 50.0% was prepared by mixing and stirring 26 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (addition number of ethylene oxide: 6.4), 10 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (addition number of ethylene oxide: 6.4), 8 g of benzotriazole type ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine type light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of monoacylphosphine oxide type photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator, and adding 114 g of 1-methoxy-2-propanol (PGM).

[Example 7]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g), 18 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), and 18 g of ethylene oxide-modified trimethylolpropane triacrylate B-2 (ethylene oxide A curable composition having a solid content of 50.0% was prepared by mixing and stirring 18 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 3.7), 4 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 6.4), 8 g of a benzotriazole ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of a hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of a monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator, and adding 114 g of 1-methoxy-2-propanol (PGM).

[Comparative Example 1]
100 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 29.2 mgKOH/g) was mixed with 8 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of a hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of a monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator, and the mixture was stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Comparative Example 2]
30 g of ethylene oxide modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide added is 0.9), 60 g of ethylene oxide modified trimethylolpropane triacrylate B-2 (the number of ethylene oxide added is 3.7), 10 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (the number of ethylene oxide added is 6.4), 8 g of benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA Corporation ADK STAB LA-87) as a light stabilizer, and 5 g of monoacylphosphine oxide-based photopolymerization initiator (IGM RESINS Co., Ltd. OmniradTPO) as a photopolymerization initiator were mixed and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Comparative Example 3]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g), 10 g of ethylene oxide modified trimethylolpropane triacrylate B-1 (number of ethylene oxide added is 0.9), 30 g of ethylene oxide modified trimethylolpropane triacrylate B-2 (number of ethylene oxide added is 3.7), 8 g of benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA Corporation ADK STAB LA-87) as a light stabilizer, and monoacylphosphine oxide-based photopolymerization initiator (IGM RESINS Co., Ltd. Omnirad TPO) as a photopolymerization initiator. 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition having a solid content of 50.0%.

[Comparative Example 4]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g), 30 g of ethylene oxide modified trimethylolpropane triacrylate B-2 (number of ethylene oxide added: 3.7), 10 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added: 6.4), 8 g of benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA Corporation ADK STAB LA-87) as a light stabilizer, and monoacylphosphine oxide-based photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) as a photopolymerization initiator. 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition having a solid content of 50.0%.

[Comparative Example 5]
60 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g), 24 g of ethylene oxide modified trimethylolpropane triacrylate B-1 (number of ethylene oxide added is 0.9), 16 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (number of ethylene oxide added is 6.4), 8 g of benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA Corporation ADK STAB LA-87) as a light stabilizer, and monoacylphosphine oxide-based photopolymerization initiator (IGM RESINS Co., Ltd. Omnirad TPO) as a photopolymerization initiator. 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition having a solid content of 50.0%.

The compositions of the curable compositions of Examples 1 to 7 and Comparative Examples 1 to 5 are summarized below.

The units of values in the tables are grams unless otherwise specified.

[Example 8]
A curable composition was prepared in the same manner as in Example 1, except that urethane acrylate A-2 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. The hydroxyl value was 27.3 mgKOH/g) was used instead of urethane acrylate A-1.

[Example 9]
A curable composition was prepared in the same manner as in Example 1, except that urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. The hydroxyl value was 28.5 mgKOH/g) was used instead of urethane acrylate A-1.

[Example 10]
A curable composition was prepared in the same manner as in Example 1, except that urethane acrylate A-4 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. The hydroxyl value was 27.6 mgKOH/g) was used instead of urethane acrylate A-1.

[Example 11]
A curable composition was prepared in the same manner as in Example 1, except that urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. The hydroxyl value was 40.8 mgKOH/g) was used instead of urethane acrylate A-1.

[Example 12]
A curable composition was prepared in the same manner as in Example 1, except that 60 g of urethane acrylate A-6 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 95 mgKOH/g. The hydroxyl value was 13.7 mgKOH/g) was mixed instead of 60 g of urethane acrylate A-1.

[Example 13]
A curable composition was prepared in the same manner as in Example 1, except that 60 g of urethane acrylate A-7 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. The hydroxyl value was 5.2 mgKOH/g) was mixed instead of 60 g of urethane acrylate A-1.

[Example 14]
A curable composition was prepared in the same manner as in Example 1, except that 60 g of urethane acrylate A-8 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. The hydroxyl value was 6.7 mgKOH/g) was mixed instead of mixing 60 g of urethane acrylate A-1.

[Example 15]
A curable composition was prepared in the same manner as in Example 1, except that 10 g of alkylene oxide unmodified (meth)acrylate B-4 was mixed in place of 10 g of ethylene oxide modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide added was 0.9).

[Comparative Example 6]
A curable composition was prepared in the same manner as in Example 1, except that urethane acrylate A-9 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and 2-hydroxyethyl acrylate (2HEA); hydroxyl value: 483 mgKOH/g) was used instead of urethane acrylate A-1.

[Comparative Example 7]
A curable composition was prepared in the same manner as in Example 1, except that urethane acrylate A-10 (synthesized from a hexamethylene diisocyanate (HDI)-based prepolymer and a lactone-modified acrylate; hydroxyl value: 11.3 mg KOH/g) was used instead of urethane acrylate A-1.

[Comparative Example 8]
A curable composition was prepared in the same manner as in Example 1, except that urethane acrylate A-11 (synthesized from norbornene diisocyanate and pentaerythritol acrylate having a hydroxyl value of 115 mgKOH/g. The hydroxyl value was 15.3 mgKOH/g) was used instead of urethane acrylate A-1.

[Comparative Example 9]
A mixture of 100 g of urethane acrylate A-12 (synthesized from 1,3,bis(isocyanatomethyl)cyclohexane (H6XDI), pentaerythritol acrylate with a hydroxyl value of 280 mgKOH/g, and dipentaerythritol acrylate with a hydroxyl value of 95 mgKOH/g; hydroxyl value of 16.4 mgKOH/g) and 8 g of a benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of a hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and a monoacylphosphine oxide-based photopolymerization initiator (IGM The mixture was mixed with 5 g of Omnirad TPO (manufactured by RESINS) and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

The compositions of the curable compositions of Examples 1, 8 to 15, and Comparative Examples 6 to 9 are summarized below.

The units of values in the tables are grams unless otherwise specified.

[Example 16]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g) and 30 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 28.5 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 17]
Instead of mixing 60 g of urethane acrylate A-1, 54 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g) and 6 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 28.5 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 18]
Instead of mixing 60 g of urethane acrylate A-1, 6 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g) and 54 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 28.5 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 19]
Instead of mixing 60 g of urethane acrylate A-1, 40 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g) and 40 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 28.5 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 20]
Instead of mixing 60 g of urethane acrylate A-1, 10 g of urethane acrylate A-1 (synthesized from hexamethylene diisocyanate (HDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 29.2 mgKOH/g) and 10 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 28.5 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 21]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-2 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 27.3 mgKOH/g) and 30 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 28.5 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 22]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 28.5 mgKOH/g) and 30 g of urethane acrylate A-4 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 27.6 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 23]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-2 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 27.3 mgKOH/g) and 30 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 40.8 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 24]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-4 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 27.6 mgKOH/g) and 30 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 40.8 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 25]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 40.8 mgKOH/g) and 30 g of urethane acrylate A-6 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 95 mgKOH/g. Hydroxyl value is 13.7 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 26]
Instead of mixing 60 g of urethane acrylate A-1, 50 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 40.8 mgKOH/g) and 10 g of urethane acrylate A-6 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 95 mgKOH/g. Hydroxyl value is 13.7 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 27]
Instead of mixing 60 g of urethane acrylate A-1, 10 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 40.8 mgKOH/g) and 50 g of urethane acrylate A-6 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 95 mgKOH/g. Hydroxyl value is 13.7 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 28]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-7 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 5.2 mgKOH/g) and 30 g of urethane acrylate A-8 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 6.7 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 29]
Instead of mixing 60 g of urethane acrylate A-1, 10 g of urethane acrylate A-7 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 5.2 mgKOH/g) and 50 g of urethane acrylate A-8 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 6.7 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 30]
Instead of mixing 60 g of urethane acrylate A-1, 50 g of urethane acrylate A-7 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 5.2 mgKOH/g) and 10 g of urethane acrylate A-8 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 6.7 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Example 31]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-7 (dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH / g. Hydroxyl value is 5.2 mgKOH / g) and 30 g of urethane acrylate A-8 (dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH / g. Hydroxyl value is 6.7 mgKOH / g) were mixed, and ethylene oxide modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide added is 0.9) was replaced with alkylene oxide non-modified (meth) acrylate B-4. Except for this, a curable composition was prepared in the same manner as in Example 1.

The compositions of the curable compositions of Examples 16 to 31 are summarized below.

[Comparative Example 10]
50 g of urethane acrylate A-2 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 27.3 mgKOH/g) and 50 g of urethane acrylate A-3 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 280 mgKOH/g. Synthesized from pentaerythritol acrylate (PEA. Hydroxyl value is 28.5 mgKOH/g) 50 g, 8 g of benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator were mixed and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Comparative Example 11]
40 g of urethane acrylate A-4 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 27.6 mgKOH/g), 20 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 280 mgKOH/g. The hydroxyl value is 40.8 mgKOH/g), and 20 g of ethylene oxide modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide added is 28 g of ethylene oxide modified trimethylolpropane triacrylate B-2 (addition number of ethylene oxide: 3.7), 8 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (addition number of ethylene oxide: 6.4), 8 g of benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 5 g of monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator were mixed and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Comparative Example 12]
40 g of urethane acrylate A-4 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 27.6 mgKOH/g), 20 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 280 mgKOH/g. The hydroxyl value is 40.8 mgKOH/g), and 10 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), 22 g of ethylene oxide modified trimethylolpropane triacrylate B-2 (ethylene oxide addition number 3.7), 4 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (ethylene oxide addition number 6.4), 8 g of benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA CORPORATION ADK STAB LA-87) as a light stabilizer, and 5 g of monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator were mixed and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Comparative Example 13]
40 g of urethane acrylate A-4 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 115 mgKOH/g. The hydroxyl value is 27.6 mgKOH/g), 20 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) with a hydroxyl value of 280 mgKOH/g. The hydroxyl value is 40.8 mgKOH/g), and 10 g of ethylene oxide-modified trimethylolpropane triacrylate B-1 (the number of ethylene oxide units added is 0.9), 4 g of ethylene oxide modified trimethylolpropane triacrylate B-2 (ethylene oxide addition number 3.7), 12 g of ethylene oxide modified trimethylolpropane triacrylate B-3 (ethylene oxide addition number 6.4), 8 g of benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA CORPORATION ADK STAB LA-87) as a light stabilizer, and 5 g of monoacylphosphine oxide-based photopolymerization initiator (OmniradTPO manufactured by IGM RESINS) as a photopolymerization initiator were mixed and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Comparative Example 14]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-13 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and sorbitol EO-modified acrylate having a hydroxyl value of 310 mgKOH/g. Hydroxyl value is 64.2 mgKOH/g) and 30 g of urethane acrylate A-4 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 27.6 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Comparative Example 15]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-14 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12MDI) and dipentaerythritol acrylate (PEA) having a hydroxyl value of 50 mgKOH/g. Hydroxyl value is mgKOH/g) and 30 g of urethane acrylate A-5 (synthesized from isophorone diisocyanate (IPDI) and pentaerythritol acrylate (PEA) having a hydroxyl value of 280 mgKOH/g. Hydroxyl value is 13.7 mgKOH/g) were mixed. A curable composition was prepared in the same manner as in Example 1.

[Comparative Example 16]
Instead of mixing 60 g of urethane acrylate A-1, 30 g of urethane acrylate A-13 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H ₁₂ MDI) and sorbitol EO modified acrylate with a hydroxyl value of 310 mg KOH/g. Hydroxyl value is 64.2 mg KOH/g) and 30 g of urethane acrylate A-14 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H12 MDI) and dipentaerythritol acrylate (PEA) with a hydroxyl value of 50 mg KOH/g. Hydroxyl value is 11.8 mg KOH/g) were mixed, but in the same manner as in Example 1, a curable composition was prepared.

Comparative Example 17: Preparation Example of Patent No. 4204106 24 g of urethane acrylate A-9 (synthesized from dicyclohexylmethane 4,4-diisocyanate (H ₁₂ MDI), polytetramethylene ether glycol (PTMEG), and 2-hydroxyethyl acrylate (2HEA). Hydroxyl value is 483 mgKOH/g), 25 g of dipentaerythritol hexaacrylate (DPHA) B-5, 62 g of tris(2-acryloyloxyethyl)isocyanurate (TAIC) B-6, 8 g of benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA STAB LA-87 manufactured by ADEKA Corporation) as a light stabilizer, and 1 g of monoacylphosphine oxide-based photopolymerization initiator (IGM The mixture was mixed with 5 g of Omnirad TPO (manufactured by RESINS) and stirred, and 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition with a solid content of 50.0%.

[Comparative Example 18] Preparation Example of Patent 6481302 91 g of urethane acrylate A-11 (synthesized from norbornene diisocyanate and pentaerythritol acrylate with a hydroxyl value of 115 mgKOH/g. Hydroxyl value is 15.3 mgKOH/g), 9 g of ethylene oxide (10 mol)-added bisphenol A diacrylate B-10, 8 g of benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, 1 g of hindered amine-based light stabilizer (ADEKA Corporation Adekastab LA-87) as a light stabilizer, and monoacylphosphine oxide-based photopolymerization initiator (IGM RESINS Co., Ltd. Omnirad TPO) as a photopolymerization initiator. 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition having a solid content of 50.0%.

[Comparative Example 19] Preparation Example of Patent 7024558 Urethane acrylate A-12 (1,3, bis (isocyanatomethyl) cyclohexane (H6XDI), pentaerythritol acrylate with a hydroxyl value of 280 mg KOH / g, and dipentaerythritol acrylate with a hydroxyl value of 95 mg KOH / g. Hydroxyl value is 16.4 mg KOH / g) 100 g, benzotriazole-based light stabilizer (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as an ultraviolet absorber, hindered amine-based light stabilizer (ADEKA Corporation Adekastab LA-87) as a light stabilizer, and monoacylphosphine oxide-based photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) as a photopolymerization initiator. 114 g of 1-methoxy-2-propanol (PGM) was added to prepare a curable composition having a solid content of 50.0%.

The compositions of the curable compositions of Comparative Examples 10 to 19 are summarized below.

[Example 32]
A curable composition was prepared in the same manner as in Example 1, except that 5 g of 2,2′-azobis(isobutyronyl) (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was mixed instead of 5 g of a monoacylphosphine oxide-based photopolymerization initiator (manufactured by IGM RESINS) as the photopolymerization initiator.

[Example 33]
A curable composition was prepared in the same manner as in Example 1, except that 5 g of benzoyl peroxide (Niper BO manufactured by NOF Corporation) was mixed instead of 5 g of a monoacylphosphine oxide-based photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) as the photopolymerization initiator.

[Example 34]
A curable composition was prepared in the same manner as in Example 1, except that 5 g of an α-hydroxyalkylphenone (Omnirad 184 manufactured by IGM RESINS) was mixed instead of 5 g of a monoacylphosphine oxide-based photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) as the photopolymerization initiator.

[Example 35]
A curable composition was prepared in the same manner as in Example 1, except that, instead of mixing 5 g of a monoacylphosphine oxide-based photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) as the photopolymerization initiator, 4 g of α-hydroxyalkylphenone (Omnirad 184 manufactured by IGM RESINS) and 2 g of benzophenone (manufactured by Matsugaki Pharmaceutical Co., Ltd.) were mixed.

[Example 36]
A curable composition was prepared in the same manner as in Example 1, except that, instead of mixing 5 g of a monoacylphosphine oxide-based photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) as a photopolymerization initiator, 4 g of α-hydroxyalkylphenone (Omnirad 184 manufactured by IGM RESINS) and 2 g of thioxatone (Omnirad DETX manufactured by IGM RESINS) were mixed.

[Example 37]
A curable composition was prepared in the same manner as in Example 1, except that 8 g of a monoacylphosphine oxide-based photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) was mixed as the photopolymerization initiator.

[Example 38]
A curable composition was prepared in the same manner as in Example 1, except that instead of mixing 8 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as the ultraviolet absorber and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA CORPORATION) as the light stabilizer, 6 g of a triazine-based ultraviolet absorber (Tinuvin 400 manufactured by BASF) and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA CORPORATION) were mixed.

[Example 39]
A curable composition was prepared in the same manner as in Example 1, except that instead of mixing 8 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as the ultraviolet absorber and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA CORPORATION) as the light stabilizer, 6 g of a cyanoacrylate-based light stabilizer (Uvinul 3035 manufactured by BASF) and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA CORPORATION) were mixed.

[Example 40]
A curable composition was prepared in the same manner as in Example 1, except that, instead of mixing 8 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as the ultraviolet absorber and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA Corporation) as the light stabilizer, 1 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA Corporation) were mixed.

[Example 41]
A curable composition was prepared in the same manner as in Example 1, except that instead of mixing 8 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) as the ultraviolet absorber and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA Corporation) as the light stabilizer, 14 g of a benzotriazole-based ultraviolet absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) and 1 g of a hindered amine-based light stabilizer (ADK STAB LA-87 manufactured by ADEKA Corporation) were mixed.

The compositions of the curable compositions of Examples 32 to 41 are summarized below.

4. Performance evaluation of curable resin composition [Sample preparation method]
The resin compositions prepared in the examples and comparative examples were applied onto a PET film (Cosmoshine A4360 manufactured by Toyobo Co., Ltd.: thickness 100 μm) using a bar coater, and pre-dried for 1 minute at 80° C. Next, ultraviolet light was irradiated under air using an ultraviolet irradiator (Light Hammer 10 manufactured by Heraeus K.K.) to an irradiation amount of 500 mJ/cm2 (illuminance 1,500 mW/cm2) to prepare a coating layer with a thickness of 5 μm.

[Heat resistance test: Adhesion]
A test piece of 100 mm x 150 mm was prepared for the laminated layer produced above. The test piece was then placed in a thermo-hygrostat set at 120 ° C for 500 hours, and then removed. For the test piece after the test, 100 squares of 1 mm x 1 mm were made on the surface of the cured film using a cutter knife, and cellophane tape was attached to the squares and then peeled off, and the number of squares that remained without peeling off the cured film was evaluated according to the following evaluation criteria.
A: No peeling of the cured film B: Number of squares that did not peel off "70 to 99/100"
C: Number of squares that did not peel off "30 to 69/100"
D: The number of squares that did not peel off was less than 30.

[Heat and humidity resistance test: transparency]
A test piece of 100 mm x 150 mm was prepared for the laminated layer produced above. The test piece was then placed in a constant temperature and humidity tester (Isuzu Manufacturing Co., Ltd., HPCF-288-40) set at a temperature of 85 ° C. and a humidity of 85% RH for 1000 hours, and then the test piece was removed. The test piece after the moist heat resistance test was subjected to haze measurement using a haze meter (NDH-5000, Nippon Denshoku Industries Co., Ltd.), and the haze before and after the test was evaluated according to the following criteria.
A: ΔHAZE = 2 or less B: ΔHAZE = 2 to 4
C:ΔHAZE=4~6
D: ΔHAZE = 6 or more

[Moisture and heat resistance test: Adhesion]
For the test specimens subjected to the moist heat resistance test under the same test conditions as those for the transparency test, 100 grids measuring 1 mm × 1 mm were created on the surface of the cured film using a cutter knife, and cellophane tape was attached to the grids and then peeled off. Based on the number of grids that remained without peeling off the cured film, evaluation was performed according to the following evaluation criteria.
A: No peeling of the cured film B: Number of squares that did not peel off "70 to 99/100"
C: Number of squares that did not peel off "30 to 69/100"
D: The number of squares that did not peel off was less than 30.

The test results are summarized below.

According to the present invention, a curable composition capable of forming a hard coat layer having excellent heat resistance and moist heat resistance is provided. The curable composition according to the present invention can be used to form a hard coat layer of many resin films and molded products such as polyethylene terephthalate (PET) resin, polycarbonate (PC) resin, poly(meth)acrylate (PMA or PMMA) resin, etc., and is particularly useful for forming a hard coat layer of devices that are used outdoors, such as devices mounted on automobiles and portable devices, and therefore require higher heat resistance and moist heat resistance.

Claims (13)

(1) a urethane (meth)acrylate (A1) obtained by reacting (a1-1) a (meth)acrylate having a structure derived from a polyhydric alcohol and having a hydroxyl value of 90 to 180 mgKOH/g, a polyisocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure, an aromatic isocyanate, and a hydrogenated product thereof, and optionally a polyol (a3);
a urethane (meth)acrylate (A) comprising a urethane (meth)acrylate (A2) obtained by reacting a (meth)acrylate (a1-2) having a structure derived from a polyhydric alcohol and having a hydroxyl value of 200 to 300 mgKOH/g, a polyisocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure , an aromatic isocyanate, and a hydrogenated product thereof, and optionally a polyol (a3);
(2) An alkylene oxide-modified tri(meth)acrylate (B), wherein the alkylene oxide-modified tri(meth)acrylate (B) is
A (meth)acrylate (B1) having an average number of repeating alkylene oxide units of 0 to 2.0;
A curable resin composition comprising: a (meth)acrylate (B2) having an average number of repeating alkylene oxide units of 3.0 to 5.0; and a (meth)acrylate (B3) having an average number of repeating alkylene oxide units of 6.0 to 8.0. 5 to 50% by mass of the (meth)acrylate (B1),
The curable resin composition according to claim 1, comprising 20 to 90% by mass of the (meth)acrylate (B2), and 5 to 30% by mass of the (meth)acrylate (B3). The curable resin composition according to claim 1, wherein the urethane (meth)acrylate (A) comprises a urethane (meth)acrylate (A1) obtained by reaction of a (meth)acrylate (a1-1) having a structure derived from a polyhydric alcohol and a hydroxyl value of 110 to 180 mgKOH/g, a polyisocyanate (a2) selected from an aliphatic isocyanate, an alicyclic isocyanate having no crosslinked structure, an aromatic isocyanate, and a hydrogenated product thereof, and, optionally, a polyol (a3). The curable resin composition according to claim 1, wherein the mass ratio of the urethane (meth)acrylate (A1) to the urethane (meth)acrylate (A2) is 10:1 to 1:2. The curable resin composition according to claim 1, wherein the urethane (meth)acrylate (A) has a structure derived from at least one polyhydric alcohol selected from the group consisting of glycerin, pentaerythritol, dipentaerythritol, and tripentaerythritol. The curable resin composition according to claim 5, wherein the urethane (meth)acrylate (A) has a structure derived from either or both of dipentaerythritol and tripentaerythritol. The curable resin composition according to claim 1, wherein the polyisocyanate (a2) is an alicyclic isocyanate having no crosslinked structure. The curable resin composition according to claim 7, wherein the alicyclic isocyanate is isophorone diisocyanate or dicyclohexylmethane diisocyanate. The curable resin composition according to claim 1, wherein the hydroxyl value of the urethane (meth)acrylate (A) is 0.1 to 10 mgKOH/g. The curable resin composition according to claim 1, wherein the alkylene oxide-modified tri(meth)acrylate (B) is selected from ethylene oxide-modified trimethylolpropane triacrylate and propylene oxide-modified trimethylolpropane triacrylate. A cured layer obtained by curing the curable resin composition according to any one of claims 1 to 10. An article having the cured layer according to claim 11 on the entire surface, one surface or part of the substrate. A method for forming a coating layer, comprising applying the curable resin composition according to any one of claims 1 to 10 onto a substrate, and curing the curable resin composition by irradiating the curable resin composition with active energy rays or by heating the curable resin composition.