JP7377578B1 - Urethane (meth)acrylate compounds and their production methods, neutralized products, aqueous resin compositions, aqueous active energy ray-curable compositions and their uses, cured products, substrates with cured films, substrates with soft coat layers, and adhesives Laminated body with agent layer - Google Patents

Abstract

[Problem] To provide a novel urethane (meth)acrylate compound that can improve water dispersibility. [Solution] A carboxyl group-containing epoxy (meth)acrylate compound (C) obtained by reacting an epoxy (meth)acrylate compound (A) with an acid anhydride (B), a polyol compound (D), and a polyisocyanate compound. A urethane (meth)acrylate compound obtained by reacting with (E), which has one or more urethane bonds, one or more (meth)acryloyl groups, and one or more carboxyl groups in the molecule, A urethane (meth)acrylate compound in which at least one carboxyl group exists in a molecular chain that is branched from a molecular chain derived from an epoxy (meth)acrylate compound (A) and does not contain a urethane bond. [Selection diagram] None

Description

The present invention provides a urethane (meth)acrylate compound, a neutralized product of the urethane (meth)acrylate compound, an aqueous resin composition containing the neutralized product, an aqueous active energy ray-curable composition containing the aqueous resin composition, A cured product of the aqueous active energy ray curable composition, a substrate with a cured film having the cured product, a soft coating agent, an adhesive, a sealant, an ink, or a resist consisting of the aqueous active energy ray curable composition, The present invention relates to a base material with a soft coat layer having the cured product, and a laminate having the cured product.

Conventionally, aqueous urethane acrylate has been produced using a method using a surfactant, a method using a hydrophilic polyol (for example, polyethylene glycol, etc.) as a polyol constituting the urethane acrylate to make it self-emulsifying, and a method using a hydrophilic method for urethane acrylate. Methods of introducing groups (eg, carboxy groups, sulfonic acid groups, tertiary amino groups, etc.) are known.
As a method for introducing a hydrophilic group into urethane acrylate, introducing a carboxy group is the easiest and most commonly used method.

In Patent Document 1, a diisocyanate compound, a carboxy group-containing diol compound, a triol compound, a terminal hydroxy group-containing glycol compound, and a hydroxy group-containing unsaturated compound are reacted as a urethane acrylate-containing composition that can be diluted with water or an alcoholic solvent. A photocurable resin composition containing a urethane acrylate obtained by subjecting a urethane compound containing a hydroxy group and an acrylate compound containing an isocyanate group at one terminal end to a urethane reaction has been proposed.

In Patent Document 2, a tertiary amine is added to a urethane (meth)acrylate prepolymer obtained by subjecting a carboxyl group-free polyol, a carboxyl group-containing polyol, an organic isocyanate, and a hydroxyl group-containing polyfunctional (meth)acrylate to a urethanization reaction. An aqueous urethane polymer dispersion obtained by neutralizing the dispersion and then adding water to urea the neutralized product, and an active energy ray-curable aqueous resin composition containing the same have been proposed.

In Patent Document 3, when synthesizing polycaprolactone polyol, by using dihydroxycarboxylic acid as an initiator, one carboxy group can be reliably introduced into one polycaprolactone polyol, and urethane acrylate resin A method has been proposed in which the carboxy group inside can be arbitrarily adjusted.

Patent No. 3911792 Japanese Patent Application Publication No. 2004-168809 Japanese Unexamined Patent Publication No. 7-157531

The urethane bonding portion of urethane acrylate has high cohesive strength and easily forms hard segments.
In the method of introducing a carboxy group using dihydroxycarboxylic acid as a chain extender, as in Patent Documents 1 and 2 above, since the site derived from the chain extender is included in the hard segment, the carboxy group is introduced. Therefore, the effect of improving water solubility or water dispersibility cannot be sufficiently obtained.
Therefore, although water solubility or water dispersibility can be improved by increasing the amount of the carboxy group-containing chain extender used, the disadvantage is that the ratio of hard segments increases, making it extremely difficult to balance the required physical properties. There is.

Further, as in Patent Document 3, the drawbacks of Patent Documents 1 and 2 can be improved by using dihydroxycarboxylic acid for ring opening of lactone, but it is difficult to apply to other than lactone polyols. Furthermore, since a carboxy group is introduced as a pendant group in the molecular chain derived from the initiator, there is a drawback that water dispersibility and dispersion stability are poor.

An object of the present invention is to provide a novel urethane (meth)acrylate compound that can improve water dispersibility.
Another object of the present invention is to provide an aqueous active energy ray-curable composition that can improve the flexibility of a cured product.

The present invention has the following aspects.
[1] A carboxyl group-containing epoxy (meth)acrylate compound (C) obtained by reacting an epoxy (meth)acrylate compound (A) and an acid anhydride (B),
A polyol compound (D),
A urethane (meth)acrylate compound obtained by reacting with a polyisocyanate compound (E),
Having one or more urethane bonds, one or more (meth)acryloyl groups, and one or more carboxy groups in one molecule,
A urethane (meth)acrylate compound in which at least one carboxyl group is present in a molecular chain that does not contain a urethane bond and is branched from a molecular chain derived from an epoxy (meth)acrylate compound (A).
[2] The urethane (meth)acrylate compound according to [1], which has a double bond equivalent of 100 to 10,000.
[3] The urethane (meth)acrylate compound according to [1] or [2], which has an acid value of 10 to 500 KOHmg/g.
[4] The urethane (meth) according to any one of [1] to [3], wherein the urethane bond content is 1 to 50% by mass based on the total mass of the urethane (meth)acrylate compound. acrylate compound.
[5] The epoxy (meth)acrylate compound (A) is at least one selected from aliphatic epoxy (meth)acrylates, alicyclic epoxy (meth)acrylates, and aromatic epoxy (meth)acrylates, [1 ] The urethane (meth)acrylate compound according to any one of [4].
[6] Any one of [1] to [5], wherein the acid anhydride (B) is at least one selected from aliphatic acid anhydrides, alicyclic acid anhydrides, and aromatic acid anhydrides. The urethane (meth)acrylate compound described in .
[7] The urethane (meth)acrylate compound according to any one of [1] to [6], wherein the polyol compound (D) is at least one selected from polyether polyols, polycarbonate polyols, and polyester polyols. .
[8] The polyisocyanate compound (E) is at least one selected from aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates, according to any one of [1] to [7]. urethane (meth)acrylate compound.

[9] A neutralized product obtained by neutralizing the urethane (meth)acrylate compound according to any one of [1] to [8] above with an amine compound.
[10] An aqueous resin composition obtained by dispersing the neutralized product according to [9] above in water.
[11] The aqueous resin composition according to [10], which has an average particle diameter of 10 to 200 nm.
[12] An aqueous active energy ray-curable composition comprising the aqueous resin composition according to [10] or [11] above, and a photopolymerization initiator.
[13] A cured product of the aqueous active energy ray-curable composition according to [12] above.
[14] The cured product according to [13], which has a Shore D hardness of 45 or less.
[15] A substrate with a cured film, which has a cured film made of the cured product according to [13] or [14] on the surface of the substrate.
[16] A soft coating agent, adhesive, sealant, ink, or resist comprising the aqueous active energy ray-curable composition according to [12] above.
[17] A base material with a soft coat layer, which has a soft coat layer made of the cured product according to [13] or [14] on the surface of the base material.
[18] A laminate having an adhesive layer made of the cured product according to [13] or [14] between the base material and the object to be adhered.
[19] Reacting the epoxy (meth)acrylate compound (A) and the acid anhydride (B) to obtain a carboxyl group-containing epoxy (meth)acrylate compound (C);
A method for producing a urethane (meth)acrylate compound, comprising a step of reacting the obtained carboxyl group-containing epoxy (meth)acrylate compound (C) with a polyol compound (D) and a polyisocyanate compound (E).

According to the present invention, a urethane (meth)acrylate compound that can improve water dispersibility is obtained.
According to the present invention, an aqueous active energy ray-curable composition that can improve the flexibility of a cured product can be obtained.

The following definitions of terms apply throughout the specification and claims.
"(Meth)acrylate" is a compound having one or more (meth)acryloyl groups.
"(Meth)acryloyl group" is a general term for acryloyl group and methacryloyl group.
"(Meth)acrylic acid" is a general term for acrylic acid and methacrylic acid.
The "weight average molecular weight" (hereinafter also referred to as "Mw") is a value measured by gel permeation chromatography (hereinafter also referred to as "GPC") in terms of standard polystyrene.
"Hydroxyl value" is the amount of potassium hydroxide required to acetylate the hydroxyl groups in the sample and neutralize the acetic acid used for acetylation, expressed in mg per 1.0 g of the sample. , which is a measure of the content of hydroxyl groups in a sample. The hydroxyl value is measured using the neutralization titration method specified in JIS K 0070:1992.

The "double bond equivalent" of the urethane (meth)acrylate compound is the mass per mole of double bond of the urethane (meth)acrylate compound, and can be expressed in g/mol.
The "acid value" of the urethane (meth)acrylate compound is the mass of potassium hydroxide required to neutralize the acid contained in 1 g of the urethane (meth)acrylate compound. For example, a urethane (meth)acrylate compound is diluted with acetone, titrated with 0.1N potassium hydroxide-methanol solution using phenolphthalein as an indicator, and the measured value is converted to the amount per 1 g of the urethane (meth)acrylate compound. Calculated by
The average particle diameter of the aqueous resin composition was determined by measuring the particle size distribution using a dynamic light scattering method on a measurement sample (25°C) in which the aqueous resin composition was diluted with water so that the solid content concentration was 1 to 2% by mass. The volume-based median diameter is defined as the average particle diameter.

Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

≪Urethane (meth)acrylate compound≫
The urethane (meth)acrylate compound (hereinafter also referred to as "compound (a)") of the present invention comprises a component (C) obtained by reacting the following components (A) and (B), and (D). This is a compound formed by reacting component (E) with component (E).
(A) Component: Epoxy (meth)acrylate compound (A)
(B) Component: Acid anhydride (B)
(C) Component: Carboxy group-containing epoxy (meth)acrylate compound (C)
(D) Component: Polyol compound (D)
(E) Component: Polyisocyanate compound (E)

Compound (a) has one or more urethane bonds, one or more (meth)acryloyl groups, and one or more carboxyl groups in one molecule.
In compound (a), at least one carboxy group exists in a molecular chain that does not contain a urethane bond and is branched from a molecular chain derived from the epoxy (meth)acrylate compound (A). The carboxy group present in a molecular chain that does not contain a urethane bond and is branched from the molecular chain derived from the epoxy (meth)acrylate compound (A) contributes to improving water dispersibility.
Preferably, in compound (a), at least one carboxy group exists at the end of a molecular chain that does not contain a urethane bond and is branched from the molecular chain derived from the epoxy (meth)acrylate compound (A).

Compound (a) has a double bond derived from a (meth)acryloyl group.
The double bond equivalent of compound (a) is preferably from 100 to 10,000, more preferably from 100 to 5,000, even more preferably from 100 to 1,000.
The double bond equivalent of compound (a) is the radically polymerizable double bond contained in one molecule of component (A), where αmol is the number of moles of component (A) required to produce 1 g of compound (a). When the number of is β, it is calculated as 1/(α×β).
When the double bond equivalent of compound (a) is at least the lower limit of the above range, it has excellent flexibility, and when it is at most the upper limit, it has excellent curability, abrasion resistance, and chemical resistance.

The acid value of compound (a) is preferably 10 to 500 KOHmg/g, more preferably 10 to 100 KOHmg/g, even more preferably 10 to 50 KOHmg/g.
When the acid value of compound (a) is at least the lower limit of the above range, it has excellent water dispersibility, and when it is at most the upper limit, it has excellent flexibility.

The content of urethane bonds (-NHCOO-) in compound (a) (hereinafter also referred to as "urethane bond concentration") is preferably 1 to 50% by mass, and 3 to 50% by mass based on the total mass of urethane (meth)acrylate. It is more preferably 25% by mass, and even more preferably 5 to 15% by mass.
When the content of the urethane bond is at least the lower limit of the above range, it has excellent curability, abrasion resistance, and chemical resistance, and when it is at most the upper limit, it has excellent flexibility.

<(A) component>
The epoxy (meth)acrylate compound (A) is a compound obtained by a condensation reaction between the epoxy group of an epoxy compound having an epoxy group and the carboxyl group of (meth)acrylic acid.
Component (A) has a (meth)acryloyl group derived from (meth)acrylic acid and a hydroxyl group derived from an epoxy group.
The number of epoxy groups present in one molecule of the epoxy compound is preferably 2 to 6, more preferably 2 to 4, even more preferably 2 to 3.
The number of (meth)acryloyl groups present in one molecule of component (A) is preferably 2 to 6, more preferably 2 to 4, even more preferably 2 to 3.
The number of hydroxyl groups present in one molecule of component (A) is preferably 2 to 6, more preferably 2 to 4, even more preferably 2 to 3.

Component (A) is preferably at least one selected from aliphatic epoxy (meth)acrylates, alicyclic epoxy (meth)acrylates, and aromatic epoxy (meth)acrylates.
Examples of aliphatic epoxy (meth)acrylates include ethylene glycol diglycidyl ether (meth)acrylic acid adduct, propylene glycol diglycidyl ether (meth)acrylic acid adduct, 1,4-butanediol diglycidyl ether (meth) Acrylic acid adduct, 1,5-pentanediol diglycidyl ether (meth)acrylic acid adduct, 1,6-hexanediol diglycidyl ether (meth)acrylic acid adduct, 1,7-heptanediol diglycidyl ether (meth) ) acrylic acid adduct, 1,8-octanediol diglycidyl ether (meth)acrylic acid adduct, neopentyl glycol diglycidyl ether (meth)acrylic acid adduct, diethylene glycol diglycidyl ether (meth)acrylic acid adduct, Propylene glycol diglycidyl ether (meth)acrylic acid adduct, polyethylene glycol diglycidyl ether (meth)acrylic acid adduct, polypropylene glycol diglycidyl ether (meth)acrylic acid adduct, glycerin triglycidyl ether (meth)acrylic acid adduct , trimethylolpropane triglycidyl ether (meth)acrylic acid adduct, sorbitol tetraglycidyl ether (meth)acrylic acid adduct, dipentaerythritol hexaglycidyl ether (meth)acrylic acid adduct, polyglycerin polyglycidyl ether (meth)acrylic acid adduct Examples include acid adducts.
Examples of alicyclic epoxy (meth)acrylates include hydrogenated bisphenol A diglycidyl ether (meth)acrylic acid adduct, hydrogenated bisphenol F diglycidyl ether (meth)acrylic acid adduct, and 3',4'-epoxycyclohexyl. Methyl-3,4-epoxycyclohexanecarboxylate (meth)acrylic acid adduct, bis(3,4-epoxycyclohexylmethyl)adipate (meth)acrylic acid adduct, 4-vinylcyclohexene dioxide (meth)acrylic acid adduct, Hexahydrophthalic acid diglycidyl ester (meth)acrylic acid adduct, hexahydroterephthalic acid diglycidyl ester (meth)acrylic acid adduct, 1,2-epoxy of 2,2-bis(hydroxymethyl)-1-butanol Examples include 4-(2-oxiranyl)cyclohexane adduct (meth)acrylic acid adduct.
Examples of aromatic epoxy (meth)acrylates include bisphenol A diglycidyl ether (meth)acrylic acid adduct, bisphenol F diglycidyl ether (meth)acrylic acid adduct, bisphenol S diglycidyl ether (meth)acrylic acid adduct, 4,4'-biphenol diglycidyl ether (meth)acrylic acid adduct, tetramethylbisphenol A diglycidyl ether (meth)acrylic acid adduct, dimethylbisphenol A diglycidyl ether (meth)acrylic acid adduct, tetramethylbisphenol F diglycidyl ether (meth)acrylic acid adduct, dimethylbisphenol F diglycidyl ether (meth)acrylic acid adduct, tetramethylbisphenol S diglycidyl ether (meth)acrylic acid adduct, dimethylbisphenol S diglycidyl ether (meth)acrylic acid adduct Acid adduct, biphenyl diglycidyl ether (meth)acrylic acid adduct, tetramethylbiphenyltetramethyl-4,4'-biphenol diglycidyl ether (meth)acrylic acid adduct, dimethyl-4,4'-biphenol diglycidyl ether (meth)acrylic acid adduct, 1-(4-hydroxyphenyl)-2-[4-(1,1-bis-(4-hydroxyphenyl)ethyl)phenyl]propane diglycidyl ether (meth)acrylic acid adduct , 2,2'-methylene-bis(4-methyl-6-tert-butylphenol) diglycidyl ether (meth)acrylic acid adduct, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenol) diglycidyl ether (meth)acrylic acid adduct, trishydroxyphenylmethane diglycidyl ether (meth)acrylic acid adduct, resorcinol diglycidyl ether (meth)acrylic acid adduct, hydroquinone diglycidyl ether (meth)acrylic acid adduct, Examples include 1,1-di-4-hydroxyphenylfluorenedi glycidyl ether (meth)acrylic acid adduct, (meth)acrylic acid adduct of novolac type epoxy resin, (meth)acrylic acid adduct of bisphenol type epoxy resin, etc. It will be done.

Component (A) is preferably selected depending on the properties of compound (a) to be obtained.
For example, aliphatic epoxy (meth)acrylate is preferred from the viewpoint of yellowing inhibition and flexibility, and 1,6-hexanediol diglycidyl ether acrylic acid adduct is more preferred.
For example, alicyclic epoxy (meth)acrylate is preferable in terms of yellowing prevention properties and toughness, and hydrogenated bisphenol A diglycidyl ether acrylic acid adduct is more preferable.
For example, aromatic epoxy (meth)acrylate is preferred in terms of wear resistance and chemical resistance, and bisphenol A diglycidyl ether acrylic acid adduct is more preferred.

The molecular weight of component (A) is preferably 100 to 10,000, more preferably 100 to 5,000, even more preferably 100 to 1,000. When the molecular weight of component (A) is at least the lower limit of the above range, it has excellent flexibility, and when it is at most the upper limit, it has excellent toughness.

<(B) component>
The acid anhydride (B) is a compound obtained by dehydration condensation of two molecules of carboxylic acid, or a compound obtained by intramolecular dehydration of two carboxy groups present in one molecule.
The number of acid anhydride groups (-C(=O)-OC(=O)-) present in one molecule of acid anhydride (B) may be one or two or more. One piece is preferred.
The acid anhydride (B) is preferably at least one selected from aliphatic acid anhydrides, alicyclic acid anhydrides, and aromatic acid anhydrides.
Examples of aliphatic acid anhydrides include succinic anhydride, fumaric anhydride, maleic anhydride, dodecenylsuccinic anhydride, itaconic anhydride, citraconic anhydride, and the like.
Examples of the alicyclic acid anhydride include hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and the like.
Examples of aromatic acid anhydrides include phthalic anhydride, 3-methylphthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like.

Component (B) is preferably selected depending on the properties of compound (a) to be obtained.
For example, aliphatic acid anhydrides are preferred in terms of yellowing inhibition and flexibility, and succinic anhydride is more preferred.
For example, from the viewpoint of yellowing inhibition and toughness, alicyclic acid anhydrides are preferred, and hexahydrophthalic anhydride is more preferred.
For example, in terms of wear resistance and chemical resistance, aromatic acid anhydrides are preferred, and phthalic anhydride is more preferred.

<(C) component>
The carboxyl group-containing epoxy (meth)acrylate compound (C) is a compound in which a carboxy group is introduced into the (A) component by a reaction between the (A) component and the (B) component. The hydroxyl group derived from component (A) also remains in component (C).
The reaction mechanism between component (A) and component (B) will be described later.

<(D) component>
The average number of hydroxyl groups per molecule of the polyol compound (D) is preferably 1 to 4, more preferably 1 to 3, even more preferably 1 to 2.5.
As component (D), two or more compounds having different average numbers of hydroxyl groups may be used in combination.
Component (D) contains at least a polyol, and may further contain a monool.
The polyol is preferably at least one selected from polyether polyols, polycarbonate polyols, and polyester polyols.
The monool is preferably at least one selected from polyether monools, polycarbonate monools, and polyester monools.
With respect to the total mass of component (D), the total content of polyols is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and may be 100% by mass.

Examples of polyether polyols include polyoxyalkylene polyols.
As the polyoxyalkylene polyol, for example, a polyoxyalkylene polyol obtained by ring-opening addition polymerization of a cyclic ether as an initiator can be used.
The initiator is preferably a compound containing a hydroxyl group, preferably a monohydric alcohol or a polyhydric alcohol, and a mixture of a monohydric alcohol and a polyhydric alcohol or a mixture of polyhydric alcohols having different numbers of hydroxyl groups can also be used as the initiator.
As the cyclic ether, alkylene oxide and tetrahydrofuran are preferred.
The number of active hydrogens (for example, the number of hydrogen atoms in hydroxyl groups) with which the cyclic ether in the initiator reacts becomes the number of hydroxyl groups in the resulting polyoxyalkylene polyol.

Specific examples of polyoxyalkylene polyols include polyoxyethylene polyol, polyoxypropylene polyol, poly(oxyethylene/oxypropylene) polyol, and polyoxytetramethylene polyol.
Any one type of polyoxyalkylene polyol may be used alone, or two or more types may be used in combination.

Examples of polycarbonate polyols include reaction products of carbonate and diol.
Specific examples of carbonates include diaryl carbonates such as diphenyl carbonate, and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.
Diols include low molecular weight diols. Examples of low molecular weight diols include diols with a molecular weight of about 60 to 300. Specific examples include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butanediol, 1,6-hexanediol, and 2-methyl-1. , 8-octanediol, nonanediol, cyclohexanedimethanol, neopentyl glycol, and 3-methyl-1,5-pentanediol.
Any one type of polycarbonate polyol may be used alone, or two or more types may be used in combination.

Examples of the polyester polyol include a reaction product of at least one selected from the above-mentioned low molecular weight diols and an acid component consisting of at least one dicarboxylic acid or a reactive derivative thereof.
Examples of the acid component include dibasic acids such as adipic acid, sebacic acid, succinic acid, maleic acid, phthalic acid, hexahydrophthalic acid, and terephthalic acid, or their anhydrides. Further, it is also possible to use a polyester polyol having an average number of hydroxyl groups of more than 2 per molecule, which is obtained by using a trifunctional or higher-functional polycarboxylic acid or a reactive derivative thereof as part of the acid component.
Furthermore, as the polyester polyol, a polyester polyol having an average number of hydroxyl groups of 1.8 to 4 per molecule, which is obtained by ring-opening addition polymerization of a cyclic ester to an initiator such as the polyhydric alcohol, may be used. can. Examples of the cyclic ester include ε-caprolactone.
Any one type of polyester polyol may be used alone, or two or more types may be used in combination.

The weight average molecular weight (Mw) of component (D) is preferably 200 or more and 15,000 or less, more preferably 300 or more and 10,000 or less, and even more preferably 400 or more and 5,000 or less. .
When the weight average molecular weight of component (D) is at least the lower limit of the above range, it has excellent flexibility, and when it is at most the upper limit, it has excellent curability, abrasion resistance, and chemical resistance.

The hydroxyl value of component (D) is preferably 30 mgKOH/g or more and 500 mgKOH/g or less, more preferably 40 mgKOH/g or more and 400 mgKOH/g or less, and preferably 45 mgKOH/g or more and 300 mgKOH/g or less. More preferred.
When the hydroxyl value of component (D) is at least the lower limit of the above range, it has excellent curability, abrasion resistance, and chemical resistance, and when it is at most the upper limit, it has excellent flexibility.

<(E) component>
The polyisocyanate compound (E) is a compound having two or more isocyanate groups (-N=C=O) in one molecule.
The number of isocyanate groups present in one molecule of component (E) is preferably 2 to 6, more preferably 2 to 4, even more preferably 2 to 3.

Component (E) is preferably at least one selected from aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates.

Examples of aliphatic polyisocyanates include hexamethylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, methylene diisocyanate, ethylene diisocyanate, butylene diisocyanate, propylene diisocyanate, octadecylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6- Examples include aliphatic diisocyanates such as hexamethylene diisocyanate and 1,10-decamethylene diisocyanate.

Examples of cycloaliphatic polyisocyanates include 4,4'-methylenebis(cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6)-diisocyanate, 1,3-(isocyanatomethyl)cyclohexane, isophorone diisocyanate, dimer Examples include alicyclic diisocyanates such as acid diisocyanate, 1,3-cyclohexylene diisocyanate, and 4,4'-methylene-bis(cyclohexyl isocyanate).

Examples of aromatic polyisocyanates include tolylene diisocyanate (also known as toluene diisocyanate), 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, xylene diisocyanate, dianisidine diisocyanate, phenyl diisocyanate, halogenated phenyl diisocyanate, 1,5- Naphthalene diisocyanate, polymethylene polyphenylene diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, 3-phenyl-2-ethylene diisocyanate, cumene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-ethoxy-1 , 3-phenylene diisocyanate, 2,4'-diisocyanate diphenyl ether, 5,6-dimethyl-1,3-phenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, benzidine diisocyanate, 9,10-anthracene diisocyanate, 4, 4'-benzyl diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate diphenylmethane, 2,6-dimethyl-4,4'-diisocyanate diphenyl, 3,3'-dimethoxy-4,4'-diisocyanate diphenyl, Examples include aromatic diisocyanates such as 1,4-anthracene diisocyanate and phenylene diisocyanate.

Component (E) is preferably selected depending on the properties of compound (a) to be obtained.
For example, aliphatic polyisocyanates are preferred in terms of yellowing inhibition and flexibility, and hexamethylene diisocyanate and trimethylhexamethylene diisocyanate are more preferred.
For example, alicyclic polyisocyanates are preferred in terms of yellowing inhibition and toughness, and isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,3-(isocyanatomethyl)cyclohexane are more preferred.
For example, aromatic polyisocyanates are preferred in terms of wear resistance and chemical resistance, and toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate are more preferred.
The polyisocyanate compound (E) may be a biuret compound, a nurate compound, an adduct compound, or an allophanate compound.

≪Production method of urethane (meth)acrylate compound≫
Compound (a) can be produced by a method having the following first step and second step.
First step: A step of reacting component (A) and component (B) to obtain component (C).
Second step: A step of reacting component (C), component (D), and component (E) to obtain compound (a).

<First step>
In the first step, the acid anhydride group (-C(=O)-OC(=O)-) in the component (B) causes a ring-opening addition reaction to the hydroxyl group in the component (A). (C) Component is generated.
A branched chain having a carboxy group is formed by ring-opening addition of an acid anhydride to some of the hydroxyl groups in component (A). That is, a structure is obtained in which a carboxy group is present in a molecular chain that is branched from a molecular chain originating from component (A) and does not contain a urethane bond.
When the number of acid anhydride groups present in component (B) is one, component (B) undergoes ring-opening addition to the hydroxyl group in component (A), resulting in branching from the molecular chain originating from component (A). , a structure in which a carboxy group is present at the end of a molecular chain that does not contain a urethane bond is obtained.
Among the hydroxyl groups in component (A), the remaining hydroxyl groups that did not react with component (B) react with polyisocyanate compound (E) in the second step to form a urethane bond. As a result, a molecular chain containing a urethane bond is formed, which is branched from the molecular chain derived from component (A).

A:B representing the ratio (mass ratio) of component (A) and component (B) to be reacted in the first step is preferably 1:0.1 to 1:10.
When the ratio of component (A) and component (B) is at least the lower limit of the above range, the resin composition has excellent water dispersion stability, and when it is at most the upper limit, it has excellent flexibility.
The molar ratio of the hydroxyl group present in component (A) and the acid anhydride group present in component (B), which are reacted in the first step, is 1:0.05 to 1. :0.9 is preferable, and 1:0.1 to 1:0.7 is more preferable. When the molar ratio of the acid anhydride group to the hydroxyl group is at least the lower limit of the above range, the resin composition has excellent water dispersion stability, and when it is at most the upper limit, it has excellent flexibility.

The first step is performed in the presence of a polymerization inhibitor.
The polymerization inhibitor is a compound that stops the progress of the polymerization reaction of the radically polymerizable unsaturated bond of the (meth)acryloyl group. Known polymerization inhibitors can be used. Specific examples of the polymerization inhibitor include methoxyhydroquinone, phenothiazine, 2,6-di-tert-butyl-4-hydroxytoluene, and the like.
The amount of the polymerization inhibitor used is preferably 0.001 to 1% by mass, more preferably 0.005 to 0.5% by mass, and 0.01% by mass based on the urethane (meth)acrylate (a) finally obtained. More preferably 0.1% by mass. When the amount of the polymerization inhibitor used is at least the lower limit of the above range, the storage stability of the urethane (meth)acrylate is improved, and when it is at most the upper limit, the ultraviolet curability of the urethane (meth)acrylate is improved.

The first step is preferably carried out in the presence of an esterification catalyst.
Specific examples of the esterification catalyst include triphenylphosphine, tetrabutylammonium bromide, and the like.
The amount of the esterification catalyst used is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and 0.1 to 3% by mass based on the total amount of components (A) and (B). is even more preferable. When the amount of the esterification catalyst used is at least the lower limit of the above range, the reaction rate is improved, and when it is at most the upper limit, the storage stability is improved.

The reaction temperature in the first step is, for example, 30 to 130°C, more preferably 60 to 100°C.
The reaction time of the first step is, for example, 1 to 24 hours, more preferably 1 to 8 hours.

<Second process>
In the second step, the hydroxyl groups in the components (C) and (D) undergo an addition reaction with the isocyanate groups in the component (E) to produce compound (a).
Specifically, the hydroxyl group in component (C), that is, the hydroxyl group that did not react with component (B) in the first step, reacts with the isocyanate group in component (E) to form a urethane bond. Further, the isocyanate group in component (E) and the hydroxyl group in component (D) react to form a urethane bond.

The ratio of component (C), component (D), and component (E) to be reacted in the second step is preferably set so that the urethane bond concentration in compound (a) falls within the above-mentioned preferred range.
Further, in the second step, it is preferred that substantially all of the isocyanate groups in component (E) react.
The infrared absorption spectrum of the reactant produced in the second step was measured, and when absorption at wavelengths of 2200 to 2300 cm ^-1 derived from isocyanate residues was no longer observed, it was determined that the isocyanate groups in component (E) were It can be determined that all of them responded.

For example, C:D:E, which represents the ratio (mass ratio) of component (C), component (D), and component (E) to be reacted in the second step, is 1:0.1:0.1 to 1: It is preferable to set the ratio within a range of 10:10.
When the ratio of component (C), component (D), and component (E) is at least the lower limit of the above range, the resin composition has excellent flexibility, and when it is at most the upper limit, the resin composition has excellent water dispersion stability.

The second step is preferably carried out in the presence of the same polymerization inhibitor as in the first step. Preferably, the second step is carried out by adding component (D) and component (E) to the reaction solution after the first step.

The second step may be performed in the presence of a urethanization catalyst from the viewpoint of shortening the reaction time.
A known urethanization catalyst can be used. Specific examples include organometallic compounds such as dibutyltin acetate, dibutyltin dilaurate, and dioctyltin dilaurate, and basic compounds such as triethylenediamine and triethylamine.
The amount of the urethanization catalyst used can be adjusted as appropriate depending on the activity of the catalyst used. For example, it is preferably 0 to 1% by mass, more preferably 0 to 0.5% by mass, even more preferably 0 to 0.1% by mass, based on urethane (meth)acrylate (a).

≪Neutralized product≫
The neutralized product according to one embodiment of the present invention (hereinafter also referred to as "this neutralized product") is a compound in which the carboxy group in compound (a) is neutralized with an amine compound. By neutralizing the carboxyl group with an amine compound, water dispersibility or water solubility is further improved.

In this neutralized product, all or some of the carboxy groups present in compound (a) may be neutralized. From the viewpoint of superior water dispersibility or water solubility, the proportion of carboxyl groups neutralized with an amine compound is preferably 80 mol% or more, and 95 mol% out of 100 mol% of all carboxyl groups in this neutralized product. The above is more preferable. The higher the proportion of carboxyl groups neutralized with the amine compound, the better the water dispersibility or water solubility tends to be.

Any amine compound may be used as long as it has an amino group and can neutralize a carboxy group.
Examples of amine compounds include methylamine, ethylamine, propylamine, isopropylamine, butylamine, amylamine, hexylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, laurylamine, pentadecylamine, cetylamine, stearylamine, and cyclohexylamine. Aliphatic primary amines such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diamylamine, dihexylamine, dioctylamine, di(2-ethylhexyl)amine, didecylamine, dilaurylamine, dicetylamine, Aliphatic secondary amines such as stearylamine, methylstearylamine, ethylstearylamine, butylstearylamine; trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tridecylamine, tristearylamine, Triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, tribranched tridecylamine, N,N-dimethylethylamine, N,N-dimethylpropylamine, N,N-dimethylisopropylamine, N,N-dimethylbutylamine , N,N-dimethylisobutylamine, N,N-dimethyloctylamine, N,N-dimethyl-2-ethylhexylamine, N,N-dimethyllaurylamine, N,N-dimethyl (branched) tridecylamine, N, N-dimethylstearylamine, N,N-diethylbutylamine, N,N-diethylhexylamine, N,N-diethyloctylamine, N,N-diethyl-2-ethylhexylamine, N,N-diethyllaurylamine, N, Aliphatic tertiary amines such as N-diisopropylmethylamine, N,N-diisopropylethylamine, N,N-diisopropylbutylamine, N,N-diisopropyl-2-ethylhexylamine; N,N-dimethylcyclohexylamine, N, Alicyclic tertiary amines such as N-diethylbenzylamine, N,N-diethylcyclohexylamine, N,N-dicyclohexylmethylamine, N,N-dicyclohexylethylamine, tricyclohexylamine; N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dibenzylmethylamine, tribenzylamine, N,N-dimethyl-4-methylbenzylamine, N,N-dimethylphenylamine, N,N-diethylphenylamine, N , N-diphenylmethylamine and other aromatic tertiary amines; N-methylpyrrolidine, N-ethylpyrrolidine, N-propylpyrrolidine, N-butylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-propylpiperidine, Cyclic amines such as N-butylpiperidine, N-methylmorpholine, N-ethylmorpholine, N-propylmorpholine, N-butylmorpholine, N-sec-butylmorpholine, N-tert-butylmorpholine, N-isobutylmorpholine, quinuclidine, etc. ; Monoethanolamine, diethanolamine, triethanolamine, 3-hydroxypropylamine, ethylenediamine, propylenediamine, hexamethylenediamine, N-methyl-1,3-propanediamine, diethylenetriamine, triethylenetetramine, 2-(2-aminoethyl Other amines such as amino) ethanol, benzylamine, 3-methoxypropylamine, 3-lauryloxypropylamine, xylylene diamine, 2,4,6-tris(dimethylaminomethyl)phenol, polyoxypropylene diamine; etc. can be mentioned.
The amine compounds may be used alone or in combination of two or more.
As the amine compound carboxylic acid, a compound having a tertiary amino group is preferable from the viewpoint of solubility in water, and triethylamine is particularly preferable.

This neutralized product can be produced, for example, by bringing the compound (a) into contact with an amine compound. The temperature at the time of contact is, for example, 20 to 70°C. The contact time is, for example, 10 to 60 minutes.

≪Aqueous resin composition≫
The aqueous resin composition according to one embodiment of the present invention is one in which the present neutralized product is dispersed in water.
Specifically, after contacting the compound (a) with an amine compound to obtain the neutralized product, water is gradually added while stirring the neutralized product, and the mixture is mixed to form an emulsified state to form an aqueous solution. A resin composition (emulsified dispersion) is obtained.
The content of the neutralized product in the aqueous resin composition is, for example, preferably 10 to 60% by mass, more preferably 15 to 50% by mass, and 20 to 40% by mass, based on the total mass of the aqueous resin composition. More preferred.

Since this neutralized product has excellent water solubility or water dispersibility, it has a characteristic that the average particle size of the aqueous resin composition is small. Furthermore, the dispersion stability of the aqueous resin composition is excellent.
For example, an aqueous resin composition having an average particle diameter of 10 to 200 nm, preferably 10 to 100 nm, more preferably 10 to 50 nm at a measurement temperature of 25° C. can be obtained.

≪Aqueous active energy ray-curable composition≫
The aqueous active energy ray-curable composition (hereinafter also referred to as "this curable composition") according to one embodiment of the present invention includes the aqueous resin composition and a photopolymerization initiator. That is, the present curable composition contains the present neutralized product, water, and a photopolymerization initiator.
A photopolymerization initiator generates active species such as radicals and cations by cleavage of the initiator or hydrogen transfer by irradiation with active energy rays.

The present curable composition further contains monomers (hereinafter also referred to as "other monomers") having polymerizable unsaturated bonds (polymerizable carbon-carbon double bonds, etc.) other than the present neutralized product and compound (a). .) may be included.
The curable composition may further contain a non-reactive diluent, if necessary.
The curable composition may further contain other components than those mentioned above, if necessary.

<Photopolymerization initiator>
Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 1- Hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2,4,6 -Trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, benzophenone, methyl o-benzoylbenzoate, hydroxybenzophenone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4- Diethylthioxanthone, 2,4-dichlorothioxanthone, 2,4,6-tris(trichloromethyl)-S-triazine, 2-methyl-4,6-bis(trichloro)-S-triazine, 2-(4-methoxyphenyl) )-4,6-bis(trichloromethyl)-S-triazine, iron-alene complexes, titanocene compounds, etc., and one or more of these can be used.

<Other monomers>
The other monomer may be a monofunctional monomer having one polymerizable unsaturated bond, or a polyfunctional monomer having two or more polymerizable unsaturated bonds. A monofunctional monomer and a polyfunctional monomer may be used together.
The monomer is preferably a water-soluble monomer. "Water-soluble monomer" refers to a monomer that mixes with water to form a homogeneous solution.

Examples of monofunctional monomers include hydroxyl group-containing monofunctional (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl acrylate, and 4-hydroxybutyl acrylate, acryloylmorpholine, dimethylacrylamide, and isobornyl acrylate. can be mentioned.
Examples of polyfunctional monomers include hydroxyl group-containing polyfunctional (meth)acrylates such as pentaerythritol di- or tri(meth)acrylate, dipentaerythritol di-, tri-, tetra- or penta(meth)acrylate, DPH(M)A, and PET. (M)A, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.
These monomers may be used alone or in combination of two or more.

<Non-reactive diluent>
The non-reactive diluent is a compound that does not have a polymerizable unsaturated bond and is liquid at room temperature.
Examples of the non-reactive diluent include organic solvents such as methanol, ethanol, isopropyl alcohol, propylene glycol monomethyl ether, methyl ethyl ketone, ethyl acetate, butyl acetate, and toluene, and water. These non-reactive diluents may be used alone or in combination of two or more.
As the non-reactive diluent, ketone solvents such as methyl ethyl ketone and ester solvents such as ethyl acetate are preferred from the viewpoint of excellent dilutability and workability in the drying process.

<Other ingredients>
Other ingredients include thermal polymerization inhibitors, ultraviolet absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, antiaging agents, antibacterial agents, antifungal agents, antifoaming agents, leveling agents, fillers, Additives include thickeners, adhesion agents, thixotropy agents, glitter materials, and the like.

<Content of each component>
The content of the neutralized product is preferably 30 to 95% by mass, more preferably 50 to 95% by mass, based on the total mass of the curable composition. If the content of the neutralized product is at least the above lower limit, the water dispersion stability of the resin composition and the flexibility of the cured product will be better.

The content of other monomers is preferably 0 to 50% by mass, more preferably 0 to 30% by mass, based on the total mass of the curable composition. If the content of other monomers is below the above upper limit, the water dispersion stability of the resin composition and the flexibility of the cured product will be better.

The ratio of the present neutralized product to the total content of the present neutralized product and other monomers is preferably 80% by mass or more, more preferably 90% by mass or more, and may be 100% by mass. If the proportion of the neutralized product is at least the above lower limit, the water dispersion stability of the resin composition and the flexibility of the cured product will be better.

The content of the photopolymerization initiator is preferably 0.1 to 10% by mass, more preferably 1 to 7% by mass, based on the total mass of the curable composition. When the content of the photopolymerization initiator is at least the lower limit, the photocurability of the curable composition is better, and when the content is at most the upper limit, the storage stability of the curable composition is better.

The content of the non-reactive diluent is preferably 0 to 80% by mass, more preferably 0 to 60% by mass, based on the total mass of the curable composition. If the content of the non-reactive diluent is below the upper limit, the water dispersion stability of the resin composition will be better.

The present curable composition can be produced by mixing the present neutralized product, a photopolymerization initiator, and, if necessary, at least one member selected from the group consisting of other monomers and other components. The mixing order of each component is not particularly limited.

≪Cured product≫
The present curable composition can be cured into a cured product by irradiation with active energy rays.
When the present curable composition is irradiated with active energy rays, active species (radicals and cations) derived from the photopolymerization initiator are generated, and the active species act on the present neutralized product and other monomers to cause polymerization. Alternatively, a crosslinking reaction occurs and the curable composition is cured.

Examples of active energy rays include visible light, ultraviolet rays, plasma, infrared rays, and ionizing radiation. Among these, ultraviolet rays are preferred from the viewpoint that irradiation devices are widely used.
Irradiation conditions for active energy rays can be appropriately selected depending on the light source used. The cumulative amount of light when irradiating ultraviolet light is, for example, 50 to 1000 mJ/cm ² .

The cured product of this curable composition has excellent flexibility.
For example, a cured product having a Shore D hardness of 45 or less, preferably 40 or less, more preferably 35 or less can be obtained.
It is thought that because the neutralized product contained in the curable composition has high water solubility or water dispersibility, the ratio of hard segments in the cured product decreases, resulting in a flexible cured product (cured film).

≪Applications of water-based active energy ray-curable composition≫
This curable composition can be used, for example, as a soft coating agent, adhesive, sealant, ink, resist, and the like. In addition, the present curable composition can be used in applications where curable elastomers are used.
The present curable composition is suitable as a soft coating agent or adhesive because it can form a flexible cured film.

[Soft coating agent]
The soft coating agent made of the present curable composition can be used to form a soft coating layer on the surface of a substrate.
For example, a coating film made of the soft coating agent is formed by applying the soft coating agent to the surface of the base material and drying it if necessary. Next, the coating film is irradiated with light and cured to form a soft coat layer (cured film) made of a cured product of the soft coating agent. Thereby, a base material with a soft coat layer is obtained.

Examples of the base material include films, sheets, and various other molded products. In terms of workability and processability, films are preferred. The thickness of the film is, for example, 10 to 250 μm.
Examples of the material of the base material include resin, metal, glass, and wood. Examples of the resin include polyester such as polyethylene terephthalate (PET), polycarbonate resin, and ABS resin.

As the coating method, any known coating method can be appropriately employed, and examples thereof include spray coating, spin coating, and gravure coating.
The drying conditions may be as long as they can remove the non-reactive diluent, and include, for example, conditions at 60 to 110°C for 0.5 to 10 minutes.
The light irradiation conditions are the same as described above.
The thickness of the coating film is set depending on the thickness of the soft coat layer to be formed.
The thickness of the soft coat layer can be, for example, 1 to 20 μm.

[glue]
The adhesive made of the present curable composition can be used to form an adhesive layer between a base material and an object to be adhered, and to integrate the substrate and the object through the adhesive layer. can.
For example, an adhesive film is formed by applying an adhesive to the surface of a base material, laminating an object to be adhered thereon, and drying as necessary. Next, the coating film is irradiated with light and cured to form an adhesive layer (cured film) made of a cured adhesive. As a result, a laminate in which the base material and the object to be adhered are integrated via the adhesive layer is obtained.

Examples of the materials of the base material and the adhered object include those similar to those of the base material in the base material with a soft coat layer.
As the adhesive application method, drying conditions, and light irradiation conditions, the same methods as those used in manufacturing the base material with a soft coat layer can be exemplified.
The thickness of the adhesive layer can be, for example, 1 to 20 μm.

Hereinafter, the present invention will be specifically described with reference to Examples.
In the following, "parts" indicate "parts by mass."

<Abbreviation>
[Polyisocyanate compound (E)]
-IPDI: Isophorone diisocyanate ("IPDI" manufactured by Evonik Japan Co., Ltd.).
- HDI: Hexamethylene diisocyanate ("HDI" manufactured by Tosoh Corporation).
- TDI: Toluene diisocyanate (“Coronate T-100” manufactured by Tosoh Corporation).
[Hydroxyacrylate]
-HEA: 2-hydroxyethyl acrylate.

[Production Example 1: Production of urethane acrylate compound]
In a 4-necked flask equipped with a thermometer, cooling tube, and stirrer, 298 parts of 1,6-hexanediol diglycidyl ether acrylic acid adduct, component (A), and 118 parts of phthalic anhydride, component (B). , 5.0 parts of triphenylphosphine, and 0.5 part of 2,6-di-tert-butyl-p-cresol were added, and after thorough stirring, the temperature was raised to 80°C and stirred for about 3 hours. Component (C) was produced by heating and reacting (first step). Subsequently, 407 parts of polytetramethylene glycol (Mw = 1011, hydroxyl value = 111 mgKOH/g) as component (D) and 177 parts of isophorone diisocyanate as component (E) were added, and after thorough stirring, The temperature was raised to 80° C., and the mixture was stirred and heated for about 24 hours to react. After the reaction, it was confirmed by infrared absorption spectrum measurement that no isocyanate residues were observed (second step). In this way, urethane acrylate compound (a) was obtained.
The weight average molecular weight (Mw), double bond equivalent, acid value, and urethane bond concentration relative to the total mass of urethane acrylate of the obtained urethane acrylate compound are shown in Table 1 (the same applies hereinafter).

[Production Examples 2 to 11]
Urethane acrylate compound (a) was obtained in the same manner as in Production Example 1, except that the types and amounts of materials introduced into the four-necked flask were as shown in Table 1.

Comparative Production Examples 1 and 2 below are examples in which component (A) and component (B) were not used, and hydroxyethyl acrylate and dihydroxycarboxylic acid were used instead.

[Comparative production example 1]
In a 4-necked flask equipped with a thermometer, cooling tube, and stirring device, 232 parts of polytetramethylene glycol as component (D), 382 parts of hexamethylene diisocyanate as component (E), and 122 parts of dimethylolpropionic acid. , 264 parts of hydroxyethyl acrylate and 0.5 part of 2,6-di-tert-butyl-p-cresol were added, and after thorough stirring, the temperature was raised to 80°C, and the mixture was stirred and heated for about 24 hours. Made it react. After the reaction, it was confirmed by infrared absorption spectrum measurement that no isocyanate residues were observed. In this way, urethane acrylate was obtained.

[Comparative production example 2]
Urethane acrylate was obtained in the same manner as in Comparative Production Example 1, except that the types and amounts of materials charged into the four-necked flask were as shown in Table 1.

[Example 1]
(Manufacture of neutralized product and aqueous resin composition)
35 parts of urethane acrylate obtained in Production Example 1 and 2.8 parts of triethylamine were placed in a flask equipped with a stirring device, and stirred for about 1 hour while maintaining the liquid temperature at 60°C to obtain a neutralized product. Thereafter, 65 parts of water was gradually added while stirring and mixed to obtain a homogeneous emulsified state to obtain an emulsified dispersion (aqueous resin composition) in which the neutralized product was dispersed in water.
Table 2 shows the proportion of carboxyl groups neutralized with the amine compound out of 100 mol% of all the carboxyl groups in the obtained neutralized product (the same applies hereinafter).
The average particle diameter of the obtained aqueous resin composition was measured using a dynamic light scattering measuring device (product name: NANOTRAC-flex, manufactured by Microtrac Bell Co., Ltd.). The results are shown in Table 2 (the same applies hereinafter).
The dispersion stability of the obtained aqueous resin composition was evaluated by the following method. The results are shown in Table 3 (the same applies hereinafter).

(Manufacture of water-based active energy ray-curable composition)
An aqueous active energy ray-curable composition was produced using the obtained aqueous resin composition.
That is, 100 parts of the emulsified dispersion (aqueous resin composition) obtained above and 4'-(2-hydroxyethoxy)-2-hydroxy-2- which is a photopolymerization initiator were placed in a flask equipped with a stirring device. 1.1 parts of methylpropiophenone (IGM Resins B.V. product name "Omnirad 2959", hereinafter also simply referred to as "Omnirad 2959") was added and stirred for about 1 hour to form a liquid resin composition. (Aqueous active energy ray curable composition) was obtained.

(Manufacture of cured product and substrate with cured film)
The obtained aqueous active energy ray-curable composition was applied onto a 100 μm thick base film (easily adhesive PET) so that the film thickness after drying would be a predetermined film thickness, and dried at 100°C. A coating film was formed.
Thereafter, the coating film was irradiated with ultraviolet rays such that the cumulative amount of light was 500 mj/cm ² to form a cured film (cured product), thereby obtaining a PET film with a cured film.
The flexibility of the obtained cured film was evaluated based on the following evaluation criteria. The results are shown in Table 3 (the same applies hereinafter).

<Evaluation method of dispersion stability>
The homogeneous emulsified dispersions (aqueous resin compositions) obtained in each example were allowed to stand while keeping the liquid temperature constant, and visually observed whether solids were separated and precipitation had occurred. Two liquid temperatures were used: 25°C and 40°C. The day when the aqueous resin composition was prepared was set as the first day, and observations were made every day to measure the number of days until separation and precipitation occurred.
In addition, for the emulsified dispersion that was left to stand at 25°C, the average particle diameter immediately after production (immediately after production) and the average particle diameter on the 14th day (after standing) were measured. The average particle size of the liquid in which separation and precipitate had occurred was determined to be "unmeasurable."
Dispersion stability was evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: Separation and precipitation did not occur on the 14th day, and the absolute value of the difference in average particle size immediately after production and after standing was less than 40 nm.
○: Separation and precipitation did not occur on the 14th day, and the absolute value of the difference in average particle size immediately after production and after standing was 40 nm or more.
Δ: Separated precipitate was generated from the 2nd day to the 14th day.
×: Separated precipitate was generated on the first day.

<Flexibility evaluation method>
(1) Bending evaluation A PET film with a cured film formed so that the thickness of the cured film after drying was 1 mm was bent by hand up to 180° with the cured film inside. Flexibility was evaluated based on the following criteria.
(Evaluation criteria)
○: No cracking occurred when bending.
x: Cracks occurred when bent.

(2) Shore D hardness The hardness of the cured film was measured using a type D durometer based on JIS K 6253-3:2012, using a PET film with a cured film formed so that the film thickness after drying was 8 mm. Shore D hardness was measured.

[Examples 2 to 11, Comparative Examples 1 and 2]
An emulsified dispersion (aqueous resin composition) was obtained in the same manner as in Example 1, except that the types and amounts of materials introduced into the flask were as shown in Table 2, and an aqueous active energy ray-curable composition was produced. , a substrate with a cured film was produced. Evaluation was made in the same manner as in Example 1.

As shown in the results in Tables 1 to 3, the aqueous resin compositions of Examples 1 to 11 in which the neutralized products of the urethane acrylate compounds (a) obtained in Production Examples 1 to 11 were dispersed in water had an average particle size of The diameter was small. This shows that the neutralized product of urethane acrylate compound (a) has excellent water dispersibility.
Furthermore, the aqueous resin compositions of Examples 1 to 11 were unlikely to cause separation and precipitation during storage and had excellent dispersion stability.
Furthermore, the cured products (cured films) of the aqueous active energy ray-curable compositions of Examples 1 to 11 had excellent bending resistance, low Shore D hardness, and excellent flexibility.
Such characteristics are obtained by introducing a carboxy group at the end of a molecular chain that does not contain a urethane bond and is branched from the molecular chain derived from the epoxy (meth)acrylate compound (A) of the urethane acrylate compound (a). This is thought to be due to a significant improvement in water solubility or water dispersibility. Furthermore, it is thought that due to the significant improvement in water solubility or water dispersibility, the ratio of hard segments in the cured product was reduced, resulting in a more flexible cured film.

On the other hand, the dispersion emulsions of Comparative Examples 1 and 2, in which the neutralized products of the urethane acrylate compounds obtained in Comparative Production Examples 1 and 2 were dispersed in water, had a large average particle size and were likely to cause separation and precipitation during storage. The water dispersibility was poor.
Furthermore, the cured products (cured films) of the aqueous active energy ray-curable compositions of Comparative Examples 1 and 2 cracked when bent up to 180°, had high Shore D hardness, and had poor flexibility. .
In the urethane acrylate compounds obtained in Comparative Production Examples 1 and 2, the carboxy group exists as a pendant group in the molecular chain interposed between two urethane bonds derived from the hydroxyl group of dihydroxycarboxylic acid. That is, it is considered that the carboxy group present between the urethane bonds with high cohesive force was included in the hard segment, and the effect of improving water solubility or water dispersibility by introducing the carboxy group was not sufficiently obtained.

Claims (16)

A carboxyl group-containing epoxy (meth)acrylate compound (C) obtained by reacting an epoxy (meth)acrylate compound (A) and an acid anhydride (B),
A polyol compound (D),
A urethane (meth)acrylate compound obtained by reacting with a polyisocyanate compound (E),
Having one or more urethane bonds, one or more (meth)acryloyl groups, and one or more carboxy groups in one molecule,
At least one carboxyl group is present in a molecular chain that does not contain a urethane bond and is branched from a molecular chain derived from the epoxy (meth)acrylate compound (A),
The double bond equivalent is 100 to 10,000, the acid value is 10 to 500 KOHmg/g, and the urethane bond content is 1 to 50% by mass based on the total mass of the urethane (meth)acrylate compound. A urethane (meth)acrylate compound. 2. The epoxy (meth)acrylate compound (A) is at least one selected from aliphatic epoxy (meth)acrylate, alicyclic epoxy (meth)acrylate, and aromatic epoxy (meth)acrylate. urethane (meth)acrylate compound. The urethane (meth)acrylate compound according to claim 1, wherein the acid anhydride (B) is at least one selected from aliphatic acid anhydrides, alicyclic acid anhydrides, and aromatic acid anhydrides. The urethane (meth)acrylate compound according to claim 1, wherein the polyol compound (D) is at least one selected from polyether polyols, polycarbonate polyols, and polyester polyols. The urethane (meth)acrylate compound according to claim 1, wherein the polyisocyanate compound (E) is at least one selected from aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. A neutralized product obtained by neutralizing the urethane (meth)acrylate compound according to any one of claims 1 to 5 with an amine compound. An aqueous resin composition obtained by dispersing the neutralized product according to claim 6 in water. The aqueous resin composition according to claim 7 , having an average particle diameter of 10 to 200 nm. An aqueous active energy ray-curable composition comprising the aqueous resin composition according to claim 7 and a photopolymerization initiator. A cured product of the aqueous active energy ray-curable composition according to claim 9 . The cured product according to claim 10 , having a Shore D hardness of 45 or less. A substrate with a cured film, the substrate having a cured film made of the cured product according to claim 10 on the surface of the substrate. A soft coating agent, adhesive, sealant, ink, or resist comprising the aqueous active energy ray-curable composition according to claim 9 . A base material with a soft coat layer, which has a soft coat layer made of the cured product according to claim 10 on the surface of the base material. A laminate comprising an adhesive layer made of the cured product according to claim 10 between the base material and the object to be adhered. A step of reacting the epoxy (meth)acrylate compound (A) and the acid anhydride (B) to obtain a carboxyl group-containing epoxy (meth)acrylate compound (C);
After a step of reacting the obtained carboxyl group-containing epoxy (meth)acrylate compound (C) with a polyol compound (D) and a polyisocyanate compound (E),
The double bond equivalent is 100 to 10,000, the acid value is 10 to 500 KOHmg/g, and the content of urethane bonds is 1 to 50% by mass based on the total mass of the urethane (meth)acrylate compound. , a method for producing a urethane (meth)acrylate compound, which produces a urethane (meth)acrylate compound.