JP7806480B2 - Active energy ray polymerizable resin composition and laminate - Google Patents

Description

The present invention relates to an active energy ray-polymerizable resin composition and a laminate.

Active energy ray-polymerizable resin compositions have excellent properties, such as high polymerization speed, excellent workability due to their ability to be used without solvents, and extremely low energy requirements during polymerization. Examples of active energy ray-polymerizable resin compositions include radical-based, cationic-based, and hybrid-based (radical and cationic) active energy ray-polymerizable resin compositions, and they are used in a wide range of fields, including adhesives and coating agents.

Polarizers used in fields related to liquid crystal displays are typically manufactured by uniaxially stretching polyvinyl alcohol (PVA) that has iodine or dye adsorbed onto it. These polyvinyl alcohol-based polarizers shrink when exposed to heat or moisture, resulting in a decrease in polarization performance. For this reason, PVA-based polarizers with a protective film attached to their surface are used as polarizing plates.

Water-based adhesives and active energy ray-polymerizable resin compositions are used to bond PVA-based polarizers and protective films. Active energy ray-polymerizable resin compositions are increasingly being used as adhesives due to their versatility as substrates for protective films, as well as their efficiency and energy conservation in production. Cationic and hybrid active energy ray-polymerizable resin compositions are being considered for their water resistance and moist heat resistance. (Patent Documents 1 and 2)

Protective films used in polarizing plates include triacetyl cellulose, acrylic, cycloolefin, polyester, and polycarbonate films. For LCD displays, the polarizing plate's configuration, including the protective film, is selected based on the LCD panel format. In recent years, polarizing plates have also been used as circular polarizers for organic EL displays by combining them with retardation films, and various protective films are selected depending on the polarizing plate's application.

As a result of the wide variety of protective films used in polarizing plate construction, polarizing plate manufacturing requires the production of polarizing plates with multiple constructions on a single production line. Therefore, one method of ensuring adhesive strength for a wide variety of protective films without replacing the active energy ray-polymerizable resin composition is to heat the active energy ray-polymerizable resin composition to erode the protective film and increase adhesive strength.

However, when cationic or hybrid active energy ray-polymerizable resin compositions are heated and run for a long period of time, their viscosity increases, which can lead to coating problems or reduced adhesive strength.

Furthermore, in circular polarizers for organic EL displays, a film that absorbs ultraviolet rays with wavelengths of 380 nm or less (ultraviolet-absorbing substrate) is sometimes used as a protective film for the polarizer to protect the organic EL elements from ultraviolet rays with wavelengths of 380 nm or less.

In this type of polarizing plate configuration, when the polarizer and protective film are bonded together using an active energy ray-polymerizable resin composition, even if UV light is irradiated through the UV-absorbing substrate, UV light with wavelengths in the range where the active energy ray-polymerizable resin composition initiates a reaction is absorbed by the UV-absorbing substrate, which can easily cause poor curing and make it difficult to fully demonstrate its performance.

Therefore, for this type of polarizing plate configuration, a technology has been investigated that uses a photoinitiator with an absorption edge at wavelengths longer than 380 nm in the active energy ray-polymerizable resin composition used to bond the polarizer and protective film. (Patent Document 3)

Japanese Patent Application Laid-Open No. 2004-245925 JP 2010-018722 A International Publication No. 2011/013663

However, these conventional active energy ray-polymerizable resin compositions currently do not achieve both curability and temperature stability.

The present invention therefore aims to provide an active energy ray-polymerizable composition that has excellent storage stability, high heat resistance, and excellent curing properties. Furthermore, its high heat resistance makes it suitable for use in hot coating processes, and its excellent curing properties mean that it has good adhesion, moist heat resistance, and flex resistance, even when used with an ultraviolet-absorbing substrate. It also aims to provide a laminate formed from this active energy ray-polymerizable composition.

As a result of extensive research into resolving the above-mentioned problems, the inventors discovered that the above-mentioned goal could be achieved by using the active energy ray-polymerizable composition shown below, leading to the completion of the present invention.

[1] An active energy ray-polymerizable resin composition comprising 1 to 99 mass% of a cationically polymerizable compound (K), 0.01 to 10 mass% of a sulfide compound (S) (excluding a thioxanthone compound (T)), and an acid generator (KE).
[2] The active energy ray-polymerizable resin composition according to [1], wherein the acid generator (KE) is an iodonium salt-based acid generator (KE1).
[3] The active energy ray-polymerizable resin composition according to [1], wherein the acid generator (KE) is a sulfonium salt-based acid generator (KE2).
[4] The active energy ray-polymerizable resin composition according to [2], further comprising a thioxanthone compound (T).
[5] The active energy ray-polymerizable resin composition according to any one of [1] to [4], further comprising a compound (M) having an α,β-ethylenically unsaturated double bond group.
[6] The active-energy ray-polymerizable resin composition according to [5], wherein the compound (M) having an α,β-ethylenically unsaturated double bond group has a mass-average molecular weight of less than 1,000 and contains a compound (Ma1) having a hydroxyl group and an α,β-ethylenically unsaturated double bond group.
[7] The active-energy ray-polymerizable resin composition according to [5] or [6], wherein the compound (M) having an α,β-ethylenically unsaturated double bond group includes a compound (Mb) having an α,β-ethylenically unsaturated double bond group having a mass average molecular weight of 1,000 or more and 60,000 or less.
[8] The active-energy ray-polymerizable resin composition according to any one of [5] to [7], wherein the compound (M) having an α,β-ethylenically unsaturated double bond group has a mass-average molecular weight of less than 1,000 and includes a compound (Ma2) having two or more α,β-ethylenically unsaturated double bond groups and at least one of a cycloalkane skeleton and a cycloalkene skeleton.
[9] The active energy ray-polymerizable resin composition according to any one of [1] to [8], which is an adhesive.
[10] A laminate obtained by laminating a resin composition layer made of the active energy ray-polymerizable resin composition according to any one of [1] to [9] on one or both sides of a substrate (F).
[11] The laminate according to [10], wherein the substrate (F) is a polyacetyl cellulose film, a polynorbornene film, a polypropylene film, a polyacrylic film, a polycarbonate film, a polyester film, a polyvinyl alcohol film, or a polyimide film.
[12] A first substrate (F), a resin composition layer made of the active energy ray-polymerizable resin composition according to any one of [4] to [9], and a second substrate (F) in this order;
A laminate in which at least one of the substrates (F) is an ultraviolet-absorbing substrate.
[13] The laminate according to claim 12, wherein both the first substrate (F) and the second substrate (F) are ultraviolet-absorbing substrates.
[14] The laminate according to any one of [10] to [13], which is used for an optical element.

The present invention provides an active energy ray-polymerizable composition that has excellent storage stability, high heat resistance, and excellent curing properties. Furthermore, its high heat resistance makes it suitable for use in hot coating processes. Furthermore, its excellent curing properties make it possible to provide an active energy ray-polymerizable composition that has good adhesion, moist heat resistance, and flex resistance, even when using an ultraviolet-absorbing substrate, and to provide a laminate formed from the active energy ray-polymerizable composition.

Preferred embodiments of the present invention are described below. In this specification, a numerical range specified using "to" includes the numerical values before and after "to" as the lower and upper limits of the range. A "major component" refers to the component with the highest content among the components.
In addition, in this specification, the terms "film" and "sheet" are not distinguished by thickness. In other words, in this specification, the term "sheet" includes thin film-like objects, and the term "film" includes thick sheet-like objects.
In this specification, the term "(meth)acrylic" means "acrylic or methacrylic" unless otherwise specified.
Furthermore, "iodonium salt-based acid generator (KE1)" is referred to as "compound (KE1),""sulfonium salt-based acid generator (KE2)" is referred to as "compound (KE2),""compound (M) having an α,β-ethylenically unsaturated double bond group" is referred to as "compound (M),""compound (Ma) having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of less than 1,000" is referred to as "compound (Ma),""compound (Ma1) having a hydroxyl group and an α,β-ethylenically unsaturated double bond group" is referred to as "compound (Ma1),""compound (Ma2) having a mass average molecular weight of less than 1,000 and having two or more cycloalkane skeletons and/or cycloalkene skeletons and two or more α,β-ethylenically unsaturated double bond groups" is referred to as "compound (Ma2)," and "compound (Ma2) having a mass average molecular weight of less than 1,000 and having two or more α,β-ethylenically unsaturated double bond groups" is referred to as "compound (Ma2).""Compound (Mb) having an α,β-ethylenically unsaturated double bond group of 1,000 or more and 60,000 or less" may be referred to as "compound (Mb),""compound (Mb1) which is a polyurethane oligomer" may be referred to as "compound (Mb1),""compound (Mb2) which is a polyester oligomer" may be referred to as "compound (Mb2),""compound (Mb3) which is a polyepoxy oligomer" may be referred to as "compound (Mb3),""other compound (Mb4) having an α,β-ethylenically unsaturated double bond group of 1,000 or more and 60,000 or less" may be referred to as "compound (Mb4),""compound (Mc) having an α,β-ethylenically unsaturated double bond group of 60,000 or more" may be referred to as "compound (Mc)," and "active energy ray-polymerizable resin composition" may be referred to as "resin composition."
Unless otherwise noted, the various components appearing in this specification may be used independently as a single type or as a mixture of two or more types.

<<Active Energy Ray-Polymerizable Resin Composition>>
The active energy ray-polymerizable resin composition of the present invention contains 1 to 99 mass % of a cationically polymerizable compound (K), 0.01 to 10 mass % of a sulfide compound (S) (excluding a thioxanthone compound (T)), and an acid generator (KE).
This makes it possible to obtain an active energy ray-polymerizable composition having excellent storage stability, high heat resistance, and excellent curing properties, and the composition can be suitably used as an adhesive, a coating agent, or the like, and has excellent adhesion, moist heat resistance, and flex resistance.
Furthermore, depending on the application, the high heat resistance makes it suitable for use in heated coating processes, and furthermore, the excellent curing properties mean that even when an ultraviolet-absorbing substrate is used, the adhesive properties, moist heat resistance, and bending resistance are excellent. Therefore, the film can be used in a variety of applications, such as hard coat films, laminates for optical elements such as polarizing films, or decorative films.

<Cationically polymerizable compound (K)>
The cationic polymerizable compound (K) is contained in an amount of 1 to 99% by mass relative to 100% by mass of the active energy ray-polymerizable resin composition. When the amount is 99% by mass or less, the active energy ray-polymerizable resin composition has high storage stability and high adhesive strength and flex resistance after long-term storage. When the amount is less than 1% by mass, the adhesion and moist heat resistance are insufficient. From the viewpoints of storage stability, substrate adhesion, and moist heat resistance, the amount is more preferably 5 to 99% by mass, and even more preferably 5 to 50% by mass.
Examples of the cationically polymerizable compound (K) include a cationically polymerizable compound (K1) which is an oxirane compound that is a three-membered cyclic ether compound, a cationically polymerizable compound (K2) which is a cyclic hetero compound other than an oxirane compound, a cyclic hetero compound, or a vinyl ether compound. Among these, from the viewpoints of excellent reactivity with active energy rays and excellent flexibility and adhesive strength of the resin composition layer after curing, cyclic hetero compounds are more preferred, and the cationically polymerizable compound (K1) is particularly preferred.

As the cationically polymerizable compound (K), it is preferable to use at least one of the cationically polymerizable compound (K1) and the cationically polymerizable compound (K2) as a main component.
The content of the cationically polymerizable compound (K1) and the cationically polymerizable compound (K2) in 100% by mass of the cationically polymerizable compound (K) is preferably from 50 to 100% by mass, and more preferably from 80 to 100% by mass, from the viewpoint of adhesion to the substrate.
When both the cationically polymerizable compound (K1) and the cationically polymerizable compound (K2) are contained, the total content thereof is preferably within the above range.

[Cationically polymerizable compound (K1)]
The cationically polymerizable compound (K1) is an oxirane compound that is a three-membered ring ether compound, and is not particularly limited as long as it is a compound in which a group formed by removing one or more hydrogen atoms from a compound having a three-membered ring cyclic ether group is bonded to another chemical structure.
Examples of the cationically polymerizable compound (K1) include aliphatic cyclic ether groups such as oxirane, methyloxirane, phenyloxirane, 1,2-diphenyloxirane, methylideneoxirane, oxiranylmethyl, oxiranylmethanol, oxiranecarboxylic acid, (chloromethyl)oxirane, (bromomethyl)oxirane, and oxiranylacetonitrile; and examples thereof include 3,4-oxiranecyclohexylmethyl 3,4-oxiranecyclohexanecarboxylate, 3,4-oxirane-6-methylcyclohexylmethyl 3,4-oxirane-6-methylcyclohexanecarboxylate, ethylenebis(3,4-oxiranecyclohexanecarboxylate), bis(3,4-oxiranecyclohexylmethyl)adipate, and bis(3,4-oxirane-6-methylcyclohexylmethyl). Examples of such alicyclic ether groups include three-membered cyclic ether groups bonded to an alicyclic ring, such as adipate, diethylene glycol bis(3,4-oxiranecyclohexyl methyl ether), ethylene glycol bis(3,4-oxiranecyclohexyl methyl ether), 2,3,14,15-dioxirane-7,11,18,21-tetraoxatrispiro-[5.2.2.5.2.2]heneicosane (a compound that can also be named 3,4-oxiranecyclohexanespiro-2',6'-dioxanespiro-3'',5''-dioxanespiro-3''',4'''-oxiranecyclohexane), 4-(3,4-oxiranecyclohexyl)-2,6-dioxa-8,9-oxiranespiro[5.5]undecane, 4-vinylcyclohexene dioxide, bis-2,3-oxiranecyclopentyl ether, and dicyclopentadiene dioxide.

The oxirane equivalent of the cationically polymerizable compound (K1) is typically 30 to 3,000 g/eq, preferably 50 to 1,500 g/eq, and more preferably 80 to 500 g/eq. An oxirane equivalent of 30 g/eq or more is preferred because the cured resin composition layer has excellent flexibility and high adhesive strength. On the other hand, an oxirane equivalent of 3,000 g/eq or less provides better compatibility with other components. 80 to 500 g/eq is preferred because it achieves a good balance.

The cationically polymerizable compound (K1) can be classified into a cationically polymerizable compound (K11) that is an oxirane compound having no alkoxysilyl group and a cationically polymerizable compound (K12) that is an oxirane compound having an alkoxysilyl group. The cationically polymerizable compound (K11) that is an oxirane compound having no alkoxysilyl group can be further classified into a cationically polymerizable compound (K111) that is an oxirane compound having an aromatic ring and a cationically polymerizable compound (K112) that is an oxirane compound having no aromatic ring. The oxirane compound having no aromatic ring can be further classified into a cationically polymerizable compound (K1121) that does not have an alicyclic structure at the oxirane moiety and a cationically polymerizable compound (K1122) that has an alicyclic structure at the oxirane moiety.
When the main component of the composition of the present invention is a cationically polymerizable compound (K), it is preferable to contain a cationically polymerizable compound (K111) which is an oxirane compound having an aromatic ring, in order to improve adhesive strength.

More specifically, examples of aromatic ring substituents include phenyl, phenylene, tolyl, tolylene, benzyl, benzylidene, benzylidine, xylyl, xylylene, phthalylidene, isophthalylidene, terephthalylidene, phenethylidene, phenethylidine, styryl, styrylidene, as-pseudocumyl, v-pseudocumyl, s-pseudocumyl, mesityl, cumenyl, α-cumyl, hydrocinnamyl, cinnamyl, cinnamylidene, cinnamylidine, duryl, durylene, thymyl, and carvacryl. Examples of substituents include cuminyl, cuminidene, neophyl, xenyl, benzhydryl, benzhydrylidene, and trityl. These include aromatic rings in which a group formed by removing one or more hydrogen atoms from benzene derivatives such as benzene, toluene, xylene, styrene, hemimellitene, pseudocumene, mesitylene, cumene, planing, isodurene, durene, cymene, and mellitene can be bonded to other chemical structures.

Other cycloalkenes include, for example, cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclobutadiene, cyclopentadiene, cyclohexadiene, cycloheptadiene, and cyclooctadiene;

For example, there is [4n+2]annulene, which has a carbon number other than benzene and has three or more carbon atoms in the ring.

For example, aromatic polycyclic compounds such as biphenyl and triphenylmethane;

For example, carbocyclic compounds such as pentalene, indene, indane, ninhydrin, naphthalene, tetralin, decalin, sapotalene, cadalene, eudalene, naphthol, menadiol, gossypol, naphthoquinone, lawsone, juglone, menadione, plumbagin, phthiocol, echinochrome A, alkannin, shikonin, acetonaphthone, naphthoic acid, naphthoyl, naphthalic acid, naphthalate, acetomenaphthone, naphthionic acid, naphthionate, naphthionyl, dansyl, croceic acid, flavian acid, chromotropic acid, neocuperone, azulene, chamazulene, guaiazulene, heptalene, octalene, and purpurogallin:

For example, as-indacene, s-indacene, as-hydroindacene, s-hydroindacene, biphenylene, acenaphthylene, acenaphthene, acenaphthoquinone, fluorene, phenalene, perinaphthene, phenanthrene, phenanthryl, phenanthryllium, phenanthridene, phenanthrylene, phenanthrol, morphol, phenanthrone, phenanthraquinone, pymanthrene, retene, anthracene, anthryl, anthrylium, anthrylidene, anthrylene, anthrol, and anthranol , anthrarobin, anthralin, dithranol, anthroyl, anthrone, bianthrone, anthraquinone, anthraquinonyl, anthraquinonylene, alizarin, quinizarin, anthrarphine, chrysadine, anthragallol, purpurin, flavopurpurin, anthrapurpurin, quinalizarin, tectoquinone, chrysophanol, chrysophanic acid, emodin, rhein, kermesic acid, carminic acid, dianthrimide, anthrimide, chrysanmic acid, colchicine, and other carbon-condensed tricyclic compounds;

For example, carbon-fused tetracyclic compounds such as trindane, trindane, fluoranthene, acephenanthrylene, acephenanthrene, aceanthrylene, aceanthrene, triphenylene, pyrene, chrysene, tetraphen, tetracene, naphthacene, rubrene, tetracycline, chlortetracycline, oxytetracycline, pleiadene, and benzanthrone;

For example, carbon-fused pentacyclic compounds such as picene, perylene, pentaphene, pentacene, tetraphenylene, cholanthrylene, and cholanthrene;

Examples include aromatic rings in which a group formed by removing one or more hydrogen atoms from a cyclic compound, such as a condensed carbon ring compound having six or more rings, such as corannulene, fluminene, anthanthrene, zethrene, hexahelicene, hexaphene, hexacene, rubicene, coronene, trinaphthylene, heptaphene, heptacene, pyranthrene, octaphene, octacene, terrylene, naphthacenonaphthacene, nonaphene, nonacene, violanthrene, violanthrone, isoviolanthrene, isoviolanthrone, ovalene, decphene, decacene, decacyclene, pentacenopentacene, quaterrylene, and hexacenohexacene, can be bonded to another chemical structure.

Cationically polymerizable compounds (K111), which are oxirane compounds having an aromatic ring, are particularly preferred, including glycidyl ether of bisphenol A, glycidyl ether of bisphenol F, 1,3-phenylenebis(methylene)bis(7-oxabicyclo[4.1.0]heptane-3-carboxylate), and 1,3-bis{(7-oxabicyclo[4.1.0]heptane-3-ylmethoxy)methyl}benzene, which have excellent heat resistance and adhesive strength.

Examples of the cationically polymerizable compound (K2), which is a cyclic hetero compound other than an oxirane compound, include compounds having an oxetanyl group, which is a four-membered ring ether, cyclic ether compounds having five or more members, and compounds having two or more oxygen or hetero groups other than oxygen.

Examples of compounds containing an oxetanyl group include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, di(1-ethyl-3-oxetanyl)methyl ether, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, phenol novolac oxetane, and 3-ethyl-{(3-triethoxysilylpropoxy)methyl}oxetane.

Cationically polymerizable compounds (K2) that are cyclic hetero compounds other than oxirane compounds include cyclic ester compounds, cyclic formal compounds, cyclic carbonate compounds, and fluorine-containing cyclic compounds. The cyclic ester compounds are preferably lactones. The cyclic formal compounds are preferably compounds selected from dioxolanes, dioxanes, and trioxanes.

The cationic polymerizable compound (K12), which is an oxirane compound having an alkoxysilyl group, is not limited as long as it has an alkoxysilyl group and an oxirane structure, but examples include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 8-glycidoxyoctyltrimethoxysilane, polysiloxane having an oxirane structure and an alkoxysilyl group in the side chain, and a polymer of 3-methacryloxypropyltriethoxysilane and glycidyl methacrylate.

From the viewpoints of the stability of the alkoxysilyl group of the cationically polymerizable compound (K12), which is an oxirane compound having an alkoxysilyl group, solubility with other components, and reactivity, it is preferable for the carbon number to be 2 or more but less than 13. Methoxy (carbon number 1) has poor storage stability, while solubility and reactivity are poor with carbon numbers of 13 or more. The desired alkoxysilyl moiety can be obtained by an exchange reaction between an oxirane compound having a highly reactive methoxysilyl group and any alcohol.

The cationically polymerizable compound (K12), which is an oxirane compound having an alkoxysilyl group, further improves substrate adhesion and moist heat resistance, so it is preferably present in an amount of 0.1 to 20% by mass relative to 100% by mass of the active energy ray-polymerizable resin composition. If it is present in an amount of 0.1% by mass or more, moist heat resistance will be further improved, and if it is present in an amount of 20% by mass or less, adhesion will be superior.

<Acid Generator (KE)>
The active energy ray-polymerizable resin composition of the present invention contains an acid generator (KE).
The acid generator (KE) generates an acid when irradiated with active energy rays such as visible light, ultraviolet light, X-rays, or electron beams, and acts catalytically to initiate the polymerization reaction of the cationically polymerizable compound (K). Examples of the acid generator include onium salt-based acid generators such as iodonium salt-based acid generators (KE1), sulfonium salt-based acid generators (KE2), diazonium salt-based acid generators, ammonium salt-based acid generators, and phosphonium salt-based acid generators.
Among these, from the viewpoint of obtaining an active energy ray-polymerizable resin composition having excellent photodecomposition efficiency and excellent curability, an iodonium salt-based acid generator (KE1) or a sulfonium salt-based acid generator (KE1) is preferred.
From the viewpoint of storage stability at high temperatures, the sulfonium salt-based acid generator (KE2) is preferred.
Furthermore, when the acid generator (KE) is an iodonium salt-based acid generator (KE1), it is preferable to further contain a thioxanthone compound (T) from the viewpoint that ultraviolet light of around 420 nm can be utilized due to the sensitizing effect of the thioxanthone compound (T).
The iodonium salt-based acid generator (KE1) reacts with ultraviolet light of around 420 nm due to its high photodecomposition efficiency combined with the sensitizing effect of the thioxanthone compound (T). Therefore, even when an ultraviolet-absorbing substrate is used as the substrate, an active energy ray-polymerizable resin composition having excellent adhesive strength, moist heat resistance, and flex resistance can be obtained.

From the viewpoint of the curability of the active energy ray-polymerizable resin composition, the content of the acid generator (KE) is preferably 0.1% by mass or more relative to 100% by mass of the active energy ray-polymerizable resin composition. On the other hand, from the viewpoint of moist heat resistance, the content is preferably 20% by mass or less, and more preferably 0.5 to 10% by mass.

[Iodonium Salt-Based Acid Generator (KE1)]
Examples of the iodonium salt acid generator (KE1) include bis(4-tert-butylphenyl)iodonium hexafluorophosphate, (4-methylphenyl)[4(2-methylpropyl)phenyl]iodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and diphenyliodonium tetrakis(pentafluoro)borate.

Commercially available iodonium salt acid generators (KE1) include bis(4-tert-butylphenyl)iodonium hexafluorophosphate (WPI-170, manufactured by Wako Pure Chemical Industries, Ltd.), WPI-113 (manufactured by Wako Pure Chemical Industries, Ltd.), IK-1 (manufactured by San-Apro Co., Ltd.), and (4-methylphenyl)[4(2-methylpropyl)phenyl]iodonium hexafluorophosphate (Omnicat 250, manufactured by IGM resins).

From the viewpoints of polymerizability, adhesion, and moist heat resistance, the content of the iodonium salt-based acid generator (KE1) is preferably 0.2% by mass or more relative to 100% by mass of the active energy ray-polymerizable resin composition. On the other hand, from the viewpoint of the storage stability of the active energy ray-polymerizable resin composition, the content is preferably 10% by mass or less, and more preferably 1 to 5% by mass.

[Sulfonium Salt-Based Acid Generator (KE2)]
Examples of the sulfonium salt acid generator (KE2) include triarylsulfonium hexafluorophosphate, triarylsulfonium hexafluoroantimonate, and triarylsulfonium tetrakis(pentafluorophenyl)borate.

Commercially available sulfonium salt acid generators (KE2) include, for example, triarylsulfonium hexafluorophosphate (CPI-110P, manufactured by San-Apro) and UVACURE 1590 (manufactured by Daicel-Cytec).

From the viewpoint of the curability of the active energy ray-polymerizable resin composition, the content of the sulfonium salt-based acid generator (KE2) is preferably 0.1% by mass or more, based on 100% by mass of the active energy ray-polymerizable resin composition. On the other hand, from the viewpoint of moist heat resistance, the content is preferably 20% by mass or less, and more preferably 0.5 to 10% by mass.

<Thioxanthone Compound (T)>
The thioxanthone compound (T) is not limited as long as it has a thioxanthone structure.
When the acid generator (KE) is an iodonium salt-based acid generator (KE1), it is preferable that the composition further contains a thioxanthone compound (T). The combination of the iodonium salt-based acid generator (KE1) and the thioxanthone compound (T) not only provides excellent storage stability and high heat resistance suitable for use in a heated coating process, but also allows a cationic reaction to proceed using light of around 420 nm, even when the substrate is an ultraviolet-absorbing substrate, thereby making it possible to obtain an active-energy ray-polymerizable resin composition with excellent curability.

Examples of thioxanthone compounds (T) include 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-hydroxythioxanthone, 2-acetoxythioxanthone, and 2-propoxythioxanthone.

The optimum amounts of the iodonium salt-based acid generator (KE1) and the thioxanthone compound (T) are affected by their concentrations relative to 100% by mass of the entire active energy ray-polymerizable resin composition, regardless of the blending amount of the cationically polymerizable compound (K).
From the viewpoints of polymerizability, adhesiveness, and moist heat resistance, the amount of the thioxanthone compound (T) is preferably 0.2 mass% or more relative to 100 mass% of the total active energy ray-polymerizable resin composition. On the other hand, if the polymerizability is too high, the adhesive strength decreases, so the amount is preferably 10 mass% or less.
When the compounding ratio of the iodonium salt acid generator (KE1) to the thioxanthone compound (T) is AM(KE1)/AM(T), AM(KE1)/AM(T) is preferably 4 to 0.2. By being in this range, the active energy ray-polymerizable resin composition can have an excellent balance of storage stability, adhesiveness, and moist heat resistance.

<Sulfide Compound (S)>
The sulfide compound (S) is not particularly limited as long as it is an organic compound in which two hydrocarbon groups are bonded to a divalent sulfur atom, except for the thioxanthone compound (T).
By including the sulfide compound (S), the resin composition can have excellent storage stability, and even when the resin composition is stored at high temperatures, the moist heat resistance and flexibility are not deteriorated. Therefore, the resin composition containing the sulfide compound (S) can be applied to high-temperature coating.
In this specification, even if a sulfide compound has a sulfonium salt structure, it is classified as a sulfonium salt-based acid generator (KE2).

The sulfide compound (S) is preferably contained in an amount of 0.01% to 10% by mass, and more preferably 0.05% to 5% by mass, based on 100% by mass of the entire resin composition. A content of 0.01% by mass or more provides storage stability and other benefits, while a content of 10% by mass or less further improves moist heat resistance.

[Sulfide compound having an aromatic ring (S1)]
The sulfide compound (S1) having an aromatic ring is preferred because it is highly effective in improving the storage stability of the resin composition, and can be classified into a sulfide compound (S11) having an aromatic ring but no nitrogen atom, and a sulfide compound (S12) having an aromatic ring and a nitrogen atom.
Furthermore, sulfide compounds (S11) having an aromatic ring but no nitrogen atom can be classified into sulfide compounds (S111) having one or less phenol structures in one molecule and sulfide compounds (S112) having two or more phenol structures.
Among these, sulfide compounds (S) having a nitrogen atom may result in a decrease in cationic reactivity, and therefore sulfide compounds (S11) having an aromatic ring but no nitrogen atom are preferred. Furthermore, when sulfide compounds (S111) are used, the balance of storage stability, adhesive strength, and moist heat resistance is most excellent, and therefore, they are preferred.

Examples of sulfide compounds (S11) having an aromatic ring but no nitrogen atom include methyl phenyl sulfide, 2-methyl-3-(methylthio)furan, furfuryl methyl sulfide, ethyl phenyl sulfide, benzyl methyl sulfide, 4-(methylthio)toluene, allyl phenyl sulfide, methoxymethyl phenyl sulfide, 4-(methylthio)benzyl alcohol, 3-methoxythioanisole, 2-methoxythioanisole, 4-methoxythioanisole, 2-(phenylthio)ethanol, furfuryl isopropyl sulfide, 2-(benzylthio)ethanol, benzyl sulfide, 2,2'-thiodiethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis(octylthiomethyl)-6-methylphenol, and 2,4-bis[(dodecylthio)methyl]-6-methylphenol.

Examples of sulfide compounds (S12) having an aromatic ring and a nitrogen atom include 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane and 1-[4-(phenylthio)phenyl]octane-1,2-dione = 2-(o-benzoyloxime).

[Sulfide compound (S2) having no aromatic ring]
Examples of the sulfide compound (S2) having no aromatic ring include allyl methyl sulfide, ethyl vinyl sulfide, 2-hydroxyethyl methyl sulfide, 3-hydroxypropyl methyl sulfide, 4-methylthio-2-butanone, methylthiomethyl acetate, (methylthio)methyl acetate, 2-hydroxyethyl sulfide, methyl 3-(methylthio)propionate, ethyl (methylthio)acetate, 2-hydroxyethyl isobutyl sulfide, butyl 2-hydroxyethyl sulfide, (methylthio)acetaldehyde dimethyl acetal, tert-butyl sulfide, sec-butyl sulfide, and sec-butyl sulfide. c-butyl sulfide, heptyl methyl sulfide, isobutyl sulfide, 3-(methylthio)propyl acetate, ethyl 3-(methylthio)propionate, 3-(methylthio)-1-hexanol, ethyl 2-hydroxyethyl sulfide, 4-hydroxythiane, 2-hydroxyethyl isopropyl sulfide, 2-(propylthio)ethanol, 2-hydroxyethyl sulfide, 2,2-bis[[3-(dodecylthio)propionic acid]3-oxopropyloxy]methyl]-1,3-propanediyl, and ditridecyl 3,3'-thiobispropionate.

The active energy ray-polymerizable resin composition of the present invention contains a sulfide compound (S), which improves the storage stability of an active energy ray-polymerizable resin composition that uses an acid generator (KE). While the mechanism behind this is unclear, it is possible that the sulfide compound stabilizes the acid generator (KE), such as an iodonium salt-based acid generator or sulfonium salt-based acid generator, or that when an iodonium salt-based acid generator or sulfonium salt-based acid generator is cleaved by heat, the coexistence of the sulfide compound (S) makes it more likely to be deactivated before acid is generated.

<Compound (M)>
The compound (M) is a compound having an α,β-ethylenically unsaturated double bond group.
The active energy ray-polymerizable resin composition of the present invention preferably contains a compound (M).
A larger content of the compound (M) is preferable because the content of the compound (K) in the resin composition decreases, thereby improving the storage stability of the resin composition of the present invention.
The compound (M) is contained in an amount of preferably 1 to 99 mass %, more preferably 50 to 95 mass %, based on 100 mass % of the active energy ray-polymerizable resin composition.
Furthermore, the compound (M) is preferably a compound having two or more α,β-ethylenically unsaturated double bond groups, since this can further improve the resistance to moist heat.

Compound (M) can be classified according to its mass average molecular weight (hereinafter referred to as Mw) into compounds (Ma) having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of less than 1,000, compounds (Mb) having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of 1,000 to 60,000, and compounds (Mc) having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of more than 60,000. Among these, it is preferable from the viewpoint of storage stability to include at least one of compounds (Mb) having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of 1,000 to 60,000 and compounds (Ma) having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of less than 1,000.
The weight average molecular weight is a polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC) measurement, and can be measured by the method described in the Examples section.

[Compound (Ma)]
The compound (Ma) is a compound having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of less than 1,000, and is classified into a compound (Ma1) having a hydroxyl group and an α,β-ethylenically unsaturated double bond group, a compound (Ma2) having two or more cycloalkane skeletons and/or cycloalkene skeletons and an α,β-ethylenically unsaturated double bond group, and a compound (Ma3) having another α,β-ethylenically unsaturated double bond group.
Among these, at least one of the compound (Ma1) and the compound (Ma2) is preferred.
The compound (Ma1) is preferred from the viewpoint of excellent adhesion to the substrate, and the compound (Ma2) is preferred from the viewpoint of excellent resistance to moist heat.

As the compound (Ma), it is preferable to use at least one of the compound (Ma1) and the compound (Ma2) as the main component.
The content of compound (Ma1) and compound (Ma2) in 100% by mass of compound (Ma) is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, from the viewpoints of adhesion and moist heat resistance.
When both the compound (Ma1) and the compound (Ma2) are contained, the total content thereof is preferably within the above range.

(Compound (Ma1))
The compound (Ma1) has a mass average molecular weight of less than 1,000 and contains a hydroxyl group and an α,β-ethylenically unsaturated double bond group. By including the compound (Ma1) in the resin composition, hydrogen bonds are formed with the hydroxyl groups of the substrate, improving adhesive strength.

There are no particular restrictions on the compound (Ma1) as long as it has a hydroxyl group in its structure, and examples include 2-hydroxyethyl (meth)acrylate, 1-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 1-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, 10-hydroxydecyl (meth)acrylate, and (meth)acrylate. Fatty acid ester-based (meth)acrylic acid esters such as 12-hydroxylauryl acrylate, ethyl-α-(meth)acrylate, and monofunctional (meth)acrylic acid; or hydroxyl group-containing aliphatic (meth)acrylic acid esters such as (meth)acrylic acid esters having terminal hydroxyl groups obtained by ring-opening addition of ε-caprolactone lactone to compounds having a hydroxyl group-containing α,β-ethylenically unsaturated double bond group; and alkylene oxide-added (meth)acrylic acid esters obtained by repeatedly adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to compounds having a hydroxyl group-containing α,β-ethylenically unsaturated double bond group;

For example, hydroxyl group-containing aliphatic vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyhexyl vinyl ether, hydroxyoctyl vinyl ether, hydroxydecyl vinyl ether, hydroxydodecyl vinyl ether, hydroxyoctadecyl vinyl ether, glyceryl vinyl ether, or alkylene oxide adduct vinyl ethers with hydroxyl groups at the terminals of repeated additions of alkylene oxides such as ethylene oxide or propylene oxide;

For example, hydroxyl group-containing aliphatic (meth)allyl alcohols or (meth)allyl ethers such as (meth)allyl alcohol, isopropenyl alcohol, dimethyl (meth)allyl alcohol, hydroxyethyl (meth)allyl ether, hydroxypropyl (meth)allyl ether, hydroxybutyl (meth)allyl ether, hydroxyhexyl (meth)allyl ether, hydroxyoctyl (meth)allyl ether, hydroxydecyl (meth)allyl ether, hydroxydodecyl (meth)allyl ether, hydroxyoctadecyl (meth)allyl ether, glyceryl (meth)allyl ether, or alkylene oxide adduct (meth)allyl ethers having hydroxyl groups at the terminals of repeated additions of alkylene oxides such as ethylene oxide or propylene oxide;

For example, compounds having an α,β-ethylenically unsaturated double bond group having multiple hydroxyl groups, such as propenediol, butenediol, heptenediol, octenediol, and glycerol di(meth)acrylate;
For example, hydroxyl group-containing (meth)acrylamides such as N-hydroxyethyl(meth)acrylamide (N-hydroxyethylacrylamide and N-hydroxyethylmethacrylamide are collectively referred to as "N-hydroxyethyl(meth)acrylamide", the same applies below), N-hydroxypropyl(meth)acrylamide, N-hydroxybutyl(meth)acrylamide, N-hydroxyhexyl(meth)acrylamide, and N-hydroxyoctyl(meth)acrylamide;

Examples of the monomer include, but are not limited to, monomers having a hydroxyl group and an ethenyl group, such as vinyl alcohol, etc. These may be used alone or in combination of two or more.
As the compound (Ma1), from the viewpoint of adhesion to the substrate, a compound having an α,β-ethylenically unsaturated double bond group having 2 to 18 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, or 1 to 2 mol of ε-caprolactone adduct 2-hydroxyethyl (meth)acrylate, is particularly preferred.

(Compound (Ma2))
The compound (Ma2) is a compound having a mass average molecular weight of less than 1,000 and having two or more cycloalkane skeletons and/or cycloalkene skeletons and α,β-ethylenically unsaturated double bond groups.

As long as the compound (Ma2) has at least two cycloalkene skeletons in total, it may be either a single cycloalkene skeleton or a bridged cyclocyclic structure. Examples include compounds (Ma21) in which the ring structures are separated by an alkyl group, ether group, ester group, etc., and compounds with bridged cyclocyclic structures such as compounds (Ma22) having a norbornane or norbornene skeleton and compounds (Ma23) having an adamantane structure. However, due to their excellent resistance to moist heat, compounds (Ma22) having a norbornane or norbornene skeleton and compounds (Ma23) having an adamantane structure are preferred.

Examples of the compound (Ma21) having two or more cycloalkane skeletons and/or cycloalkene skeletons and having an α,β-ethylenically unsaturated double bond group whose ring structures are separated from each other include hydrogenated biphenol A diacrylate and 3,3-dicyclopropyl acrylate.
The α,β-ethylenically unsaturated double bond group-containing compound (Ma22) having a norbornene and/or norbornane skeleton may be any compound as long as it has a norbornene and/or norbornane skeleton and one or more ethylenically unsaturated double bonds, and examples thereof include dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dimethylol dicyclopentane di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, and isobornyl (meth)acrylate.

Among compounds (Ma22) having a norbornane or norbornene skeleton, compounds having three or more cyclic skeletons are particularly preferred, as they increase bulkiness, suppress cure shrinkage, and improve adhesive strength. Specific examples of these compounds include dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dimethyloldicyclopentanedi(meth)acrylate.

The α,β-ethylenically unsaturated double bond group-containing compound (Ma23) having an adamantane skeleton is a radical polymerizable compound having three or more cyclic skeletons, and is preferred from the viewpoint of excellent heat resistance and adhesiveness. Specific examples of compound (Ma23) include 3-hydroxy-1-adamantyl(meth)acrylate, 2-methyl-2-adamantyl(meth)acrylate, 2-ethyl-2-adamantyl(meth)acrylate, 2-propyl-2-adamantyl(meth)acrylate, 3,5-dihydroxy-1-adamantyl(meth)acrylate, 1,3-adamantyldiol di(meth)acrylate, 1,3,5-adamantyltri(meth)acrylate, 3-hydroxy-1,5-adamantyldi(meth)acrylate, and 3,5-dihydroxy-1-adamantyl(meth)acrylate. However, due to their excellent adhesive properties, 3-hydroxy-1-adamantyl acrylate, 2-methyl-2-adamantyl acrylate, and 2-ethyl-2-adamantyl acrylate are preferred.

[Compound (Mb)]
Compound (Mb) is a compound having an α,β-ethylenically unsaturated double bond group and a mass average molecular weight of 1,000 to 60,000, and is a compound generally referred to as an oligomer. Compound (Mb) is further classified into compounds (Mb1) which are polyurethane oligomers, compounds (Mb2) which are polyester oligomers, compounds (Mb3) which are polyepoxy oligomers, and compounds (Mb4) which have an α,β-ethylenically unsaturated double bond group and a mass average molecular weight of 1,000 to 60,000. At least one oligomer selected from the group consisting of compounds (Mb1), (Mb2), and (Mb3) is preferred, and can be used without any particular limitation.
Compound (Mb) is preferred because it has excellent flex resistance. Of these, compound (Mb1) is preferred because it has a urethane bond with high polarity, resulting in a good balance between the toughness of the coating film and the adhesion to the substrate, and it has particularly excellent flex resistance.

The mass average molecular weight of compound (Mb) is 1000 to 60,000, and from the viewpoint of compatibility of the polymerized coating film and good flex resistance, a range of 5000 to 50,000 is preferred. Having compound (Mb) with a mass average molecular weight in this range improves the fluidity of the active energy ray-polymerizable resin composition and its compatibility with compounds (M) other than compound (Mb), thereby improving the coatability of the active energy ray-polymerizable resin composition. Furthermore, when used as an adhesive, this is preferred because it provides the polymerized coating film with excellent flex resistance and suppresses whitening of the coating film.

The content of compound (Mb) is preferably 1 to 40% by mass, and more preferably 2 to 20% by mass, based on 100% by mass of the active energy ray-polymerizable resin composition. A content of 1% by mass or more further improves flex resistance, while a content of 40% by mass or less prevents the viscosity from becoming too high, making it easier to control the film thickness during coating.

(Compound (Mb1))
Compound (Mb1) is a polyurethane oligomer, and is a compound obtained by reacting a compound having at least one isocyanate group with compound (Ma1), or a compound obtained by reacting a urethane prepolymer having a terminal isocyanate group obtained by reacting a compound having at least one isocyanate group with a polyhydric alcohol with compound (Ma1), or a compound obtained by reacting a urethane prepolymer having a terminal isocyanate group obtained by reacting a compound having at least one isocyanate group with a polyhydric alcohol with a compound having at least one amino group with compound (Ma1). Polyurethane oligomer (Mb1) also includes those containing a urea bond obtained by reacting an isocyanate group with an amino group.

Compound (Mb1) is preferably a compound (Mb1) consisting of a diol compound, a compound having two isocyanate groups, and compound (Ma1). This is because, theoretically, a structure having acrylate groups at both ends of one molecule results in a good balance between flexibility and crosslinking density, and excellent substrate adhesion and toughness, resulting in good flex resistance.

Compounds having at least one isocyanate group include monofunctional polyisocyanates and polyfunctional isocyanates, such as aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates, respectively. More specific examples of monofunctional polyisocyanates include methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, octyl isocyanate, decyl isocyanate, octadecyl isocyanate, stearyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, benzyl isocyanate, p-chlorophenyl isocyanate, p-nitrophenyl isocyanate, 2-chloroethyl isocyanate, 2,4-dichlorophenyl isocyanate, and methyl ... Examples of such isomers include phenyl isocyanate, 3-chloro-4-methylphenyl isocyanate, trichloroacetyl isocyanate, chlorosulfonyl isocyanate, (R)-(+)-α-methylbenzyl isocyanate, (S)-(-)-α-methylbenzyl isocyanate, (R)-(-)-1-(1-naphthyl)ethyl isocyanate, (R)-(+)-1-phenylethyl isocyanate, (S)-(-)-1-phenylethyl isocyanate, and p-toluenesulfonyl isocyanate.

More specific examples of aromatic polyisocyanates among polyfunctional isocyanates include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4',4"-triphenylmethane triisocyanate.

Aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also known as HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

Examples of aromatic aliphatic polyisocyanates include ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, and 1,3-tetramethylxylylene diisocyanate.

Examples of alicyclic polyisocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,4-bis(isocyanatomethyl)cyclohexane.

In addition, 2-methylpentane-2,4-diol adducts of some of the above polyisocyanates, trimers having an isocyanurate ring, etc. can also be used in combination. Polyphenylmethane polyisocyanate (also known as PAPI), naphthylene diisocyanate, and modified polyisocyanates thereof can also be used. Modified polyisocyanates that can be used include those containing a carbodiimide group, a uretdione group, a uretoimine group, a biuret group reacted with water, or an isocyanurate group, or two or more of these groups. Reaction products of polyols and diisocyanates can also be used as compounds containing at least two isocyanate groups.

Aliphatic diisocyanate or alicyclic diisocyanate compounds are preferred as compounds having an isocyanate group from the standpoint of flex resistance.

In addition, examples of polyhydric alcohols include relatively low molecular weight polyols having a number average molecular weight (Mn) of about 50 to 500, and relatively high molecular weight polyols having a number average molecular weight (Mn) of 500 to 30,000, and each of these can be used without any particular restrictions.
The number average molecular weight is a polystyrene-equivalent number average molecular weight determined by gel permeation chromatography (GPC).

Specific examples of relatively low molecular weight polyols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 3,3'-dimethylolheptane, 2-butyl-2-ethyl-1,3-propanediol, polyoxyethylene glycol (addition mole number 10 or less), ... Aliphatic or alicyclic diols such as propylene glycol (addition mole number 10 or less), propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, cyclohexanedimethanol, tricyclodecanedimethanol, cyclopentadienedimethanol, and dimer diol;

Examples include aromatic diols such as 1,3-bis(2-hydroxyethoxy)benzene, 1,2-bis(2-hydroxyethoxy)benzene, 1,4-bis(2-hydroxyethoxy)benzene, 4,4'-methylenediphenol, 4,4'-(2-norbornylidene)diphenol, 4,4'-dihydroxybiphenol, o-, m- and p-dihydroxybenzene, 4,4'-isopropylidenephenol, and addition-type bisphenols in which alkylene oxides are added to bisphenols.

Examples of the raw material bisphenol for the addition type bisphenol include bisphenol A and bisphenol F, and examples of the raw material alkylene oxide include ethylene oxide and propylene oxide.
More specifically, the relatively high molecular weight polyols include high molecular weight polyether polyols, high molecular weight polyester polyols, high molecular weight polyamide polyols, high molecular weight polycarbonate polyols, and high molecular weight polyurethane polyols. High molecular weight polycarbonate polyols can be obtained by reacting the above-mentioned relatively low molecular weight diols with carbonate esters or phosgene.

Examples of commercially available high molecular weight polyester polyols include the Vylon series manufactured by Toyobo Co., Ltd., the Kuraray Polyol P series manufactured by Kuraray Co., Ltd., and the Kyowapol series manufactured by Kyowa Hakko Chemical Co., Ltd.
As a commercially available product of the high molecular weight polyamide polyol, TPAE617 manufactured by Fuji Chemical Industry Co., Ltd. can be used.
Examples of commercially available high molecular weight polycarbonate polyols include Oxymer N112 manufactured by Perstorp, PCDL series manufactured by Asahi Kasei Chemicals Corporation, Kuraray Polyol PMHC series and Kuraray Polyol C series manufactured by Kuraray Co., Ltd.

Commercially available high molecular weight polyurethane polyols include, for example, the Vylon UR series manufactured by Toyobo Co., Ltd., and Takelac E158 (hydroxyl value = 20, acid value < 3), Takelac E551T (hydroxyl value = 30, acid value < 3), and Takelac Y2789 (hydroxyl value = 10, acid value < 2), all manufactured by Mitsui Chemicals Polyurethanes, Inc.
In addition, polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone diol, poly(β-methyl-γ-valerolactone) diol, and polyvalerolactone diol are also included in the high molecular weight polyols that can be used as the high molecular weight polyol.

High molecular weight polyether diols or high molecular weight polyester diols are preferred as polyhydric alcohols in terms of adhesion.

Specific examples of amines having an amino group include aliphatic polyamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, triaminopropane, 2,2,4-trimethylhexamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2-hydroxyethylethylenediamine, hexamethylenediamine 2-hydroxyethylethylenediamine, N-(2-hydroxyethyl)propylenediamine, (2-hydroxyethylpropylene)diamine, (di-2-hydroxyethylethylene)diamine, (di-2-hydroxyethylpropylene)diamine, (2-hydroxypropylethylene)diamine, (di-2-hydroxypropylethylene)diamine, and piperazine;
Alicyclic polyamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine;
Aromatic diamines such as phenylenediamine, xylylenediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, diethyltoluenediamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, and 4,4'-bis-(sec-butyl)diphenylmethane can be used.

(Compound (Mb2))
The compound (Mb2) is a polyester oligomer, and may be a compound obtained by esterifying a hydroxyl group at the terminal or in the polyester chain of a polyester obtained by polycondensing a polybasic acid and a polyhydric alcohol in the main chain skeleton with a compound having an α,β-ethylenically unsaturated double bond group having one or more carboxyl groups in the molecule, such as (meth)acrylic acid or maleic acid, or a compound obtained by esterifying a carboxyl group at the terminal or in the polyester chain with the aforementioned compound (Ma1), such as 2-hydroxyethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate. Other examples that can be used as the polyester oligomer (Mb2) include polyester oligomers obtained from acid anhydrides, glycidyl (meth)acrylate, and compounds having at least one hydroxyl group.

The polyhydric alcohol may be the same as that described in the synthesis of compound (Mb1).

The polybasic acids mentioned above include aliphatic, alicyclic, and aromatic acids, each of which can be used without particular restrictions. More specific examples of aliphatic polybasic acids include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, suberic acid, maleic acid, chloromaleic acid, fumaric acid, dodecanedioic acid, pimelic acid, citraconic acid, glutaric acid, itaconic acid, succinic anhydride, and maleic anhydride. These aliphatic dicarboxylic acids and their anhydrides can also be used. Additionally, anhydride derivatives such as succinic anhydride derivatives (methyl succinic anhydride, 2,2-dimethyl succinic anhydride, butyl succinic anhydride, isobutyl succinic anhydride, hexyl succinic anhydride, octyl succinic anhydride, dodecenyl succinic anhydride, phenyl succinic anhydride, etc.), glutaric anhydride derivatives (glutaric anhydride, 3-allyl glutaric anhydride, 2,4-dimethyl glutaric anhydride, 2,4-diethyl glutaric anhydride, butyl glutaric anhydride, hexyl glutaric anhydride, etc.), and maleic anhydride derivatives (2-methyl maleic anhydride, 2,3-dimethyl maleic anhydride, butyl maleic anhydride, pentyl maleic anhydride, hexyl maleic anhydride, octyl maleic anhydride, decyl maleic anhydride, dodecyl maleic anhydride, 2,3-dichloromaleic anhydride, phenyl maleic anhydride, 2,3-diphenyl maleic anhydride, etc.) can also be used.

Specific examples of alicyclic polybasic acids include alicyclic dicarboxylic acids such as dimer acid, cyclopropane-1α,2α-dicarboxylic acid, cyclopropane-1α,2β-dicarboxylic acid, cyclopropane-1β,2α-dicarboxylic acid, cyclobutane-1,2-dicarboxylic acid, cyclobutane-1α,2β-dicarboxylic acid, cyclobutane-1α,3β-dicarboxylic acid, cyclobutane-1α,3α-dicarboxylic acid, (1R)-cyclopentane-1β,2α-dicarboxylic acid, trans-cyclopentane-1,3-dicarboxylic acid, (1β,2β)-cyclopentane-1,3-dicarboxylic acid, (1β,3β)-cyclopentane-1,3-dicarboxylic acid, (1S,2S)-1,2-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. Examples of suitable dicarboxylic acids include saturated alicyclic dicarboxylic acids such as 1,1-cycloheptanedicarboxylic acid, cubane-1,4-dicarboxylic acid, 2,3-norbornanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydrophthalic acid, and tetrahydrophthalic acid, and unsaturated alicyclic dicarboxylic acids having one or two unsaturated double bonds in the ring, such as 1-cyclobutene-1,2-dicarboxylic acid, 3-cyclobutene-1,2-dicarboxylic acid, 1-cyclopentene-1,2-dicarboxylic acid, 4-cyclopentene-1,3-dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 2-cyclohexene-1,2-dicarboxylic acid, 3-cyclohexene-1,2-dicarboxylic acid, 4-cyclohexene-1,3-dicarboxylic acid, and 2,5-hexadiene-1α,4α-dicarboxylic acid. These alicyclic dicarboxylic acids and their anhydrides can also be used.

In addition, hydrogenated phthalic anhydride derivatives such as derivatives of hexahydrophthalic anhydride (3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride) and derivatives of tetrahydrophthalic anhydride (1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride, methylbutenyl-1,2,3,6-tetrahydrophthalic anhydride, etc.) can also be used as alicyclic dicarboxylic acid anhydrides.

More specifically, examples of aromatic polybasic acids include aromatic dicarboxylic acids such as o-phthalic acid, isophthalic acid, terephthalic acid, toluene dicarboxylic acid, 2,5-dimethylterephthalic acid, 2,2'-biphenyl dicarboxylic acid, 4,4-biphenyl dicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, norbornene dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, phenylindanedicarboxylic acid, 1,2-azuledicarboxylic acid, and 1,3-azuledicarboxylic acid. Examples of aromatic dicarboxylic acids that can be used include 4,5-azulenedicarboxylic acid, (-)-1,3-acenaphthenedicarboxylic acid, 1,4-anthracenedicarboxylic acid, 1,5-anthracenedicarboxylic acid, 1,8-anthracenedicarboxylic acid, 2,3-anthracenedicarboxylic acid, 1,2-phenanthrenedicarboxylic acid, 4,5-phenanthrenedicarboxylic acid, and 3,9-perylenedicarboxylic acid, as well as aromatic dicarboxylic acid anhydrides such as phthalic anhydride and 4-methylphthalic anhydride. These aromatic dicarboxylic acids and their anhydrides can be used.

Furthermore, acid anhydrides such as chlorendic anhydride, HET acid anhydride, biphenyl dicarboxylic anhydride, himic anhydride, endomethylene-1,2,3,6-tetrahydrophthalic anhydride, methyl-3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride, 1,2-cyclohexane dicarboxylic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, methylcyclohexene dicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, and octahydro-1,3-dioxo-4,5-isobenzofurandicarboxylic anhydride can also be used as polybasic acids.

(Compound (Mb3))
Compound (Mb3) is a polyepoxy oligomer, which is obtained by reacting a compound having a glycidyl group with a compound having an α,β-unsaturated double bond group having one or more carboxyl groups in the molecule, such as (meth)acrylic acid or maleic acid, and representative examples include bisphenol type, epoxidized oil type, phenol novolac type, and alicyclic type. Bisphenol type polyepoxy oligomers are obtained by reacting a bisphenol type diglycidyl ether obtained by reacting a bisphenol with epichlorohydrin with a compound having an α,β-unsaturated double bond group having one or more carboxyl groups in the molecule, such as (meth)acrylic acid.

Epoxidized oil polyepoxy oligomers can be those obtained by reacting an epoxidized oil such as soybean oil with a compound such as (meth)acrylic acid or maleic acid that has an α,β-unsaturated double bond group and one or more carboxyl groups in the molecule. Novolac polyepoxy oligomers can be those obtained by reacting a novolac epoxy resin with a compound such as (meth)acrylic acid that has an α,β-unsaturated double bond group and one or more carboxyl groups in the molecule. Alicyclic polyepoxy oligomers can be those synthesized by reacting an alicyclic epoxy resin with a compound such as (meth)acrylic acid that has an α,β-unsaturated double bond group and one or more carboxyl groups in the molecule.

<Radical Polymerization Initiator (E)>
The active energy ray-polymerizable resin composition of the present invention may further contain a radical polymerization initiator (E). By using the radical polymerization initiator (E), the radical polymerization reaction can be promoted.
In this specification, even if a compound falls under the category of the radical polymerization initiator (E), it is classified as a sulfide compound (S) if it has a sulfide structure.

The radical polymerization initiator (E) can be arbitrarily selected from known initiators and used. Specific examples thereof include 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthofluorenone, benzaldehyde, anthraquinone, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-diaminobenzophenone, benzoin propyl ether, benzoin ethyl ether, benzil dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-oxanthone, camphorquinone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. Examples of commercially available products include Irgacure 184, 907, 651, 1700, 1800, 819, 369, 261, DAROCUR-TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF), Omnirad 819 (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, manufactured by IGM Resins B.V.), Darocur-1173 (manufactured by Merck), Ezacure KIP150, TZT (manufactured by Nippon SiberHegner), Kayacure BMS, and Kayacure DMBI (manufactured by Nippon Kayaku Co., Ltd.).
2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide or bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is preferred because of its photobleaching properties.

The radical initiator (E) is preferably contained in an amount of 0.01 to 20% by mass based on 100% by mass of the active energy ray-polymerizable resin composition.

Examples of active energy rays include ultraviolet rays and electron beams.
When the radical polymerization reaction is carried out by electron beam irradiation, it is not necessary to include a polymerization initiator.

In addition, to improve the performance of the radical initiator (E), an active energy ray sensitizer may be used in combination. Typical examples of active energy ray sensitizers include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles, and other nitrogen-containing compounds, but anthracenes, benzophenones, perylene, phenothiazine, rose bengal, etc. are preferably used.

<Other ingredients>
In addition to the components described above, additives can be appropriately blended into the active energy ray-polymerizable resin composition of the present invention, as long as the effects of the present invention are not impaired. For example, organic or inorganic fillers can be blended to reduce polymerization cure shrinkage, reduce thermal expansion coefficient, improve dimensional stability, improve elastic modulus, adjust viscosity, improve thermal conductivity, improve strength, improve toughness, and improve coloring. Examples of such fillers include polymers, ceramics, metals, metal oxides, metal salts, dyes and pigments, and the like, and the shape thereof is not particularly limited, such as particulate or fibrous. When blending the above polymers, softeners, plasticizers, flame retardants, storage stabilizers, antioxidants, UV absorbers, thixotropy-imparting agents, dispersion stabilizers, fluidity-imparting agents, antifoaming agents, etc., can also be dissolved, semi-dissolved, or micro-dispersed in the active energy ray-polymerizable resin composition as polymer blends or polymer alloys rather than as fillers.

The active energy ray-polymerizable resin composition of the present invention is preferably substantially free of water or organic solvents in terms of drying equipment and drying energy. However, if the acid generator (KE) or radical initiator (E) is poorly soluble in the cationically polymerizable compound (K) or the compound (M) having an α,β-ethylenically unsaturated double bond group or if the composition has high viscosity, a small amount of water or organic solvent may be contained to dissolve the acid generator (KE) or radical initiator (E). The content of water or organic solvent in the active energy ray-polymerizable resin composition is 5% by mass or less. Usable organic solvents are not particularly limited, but specific examples include organic solvents such as methanol, ethanol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, cyclohexane, toluene, xylene, and other hydrocarbon solvents, as well as water. The viscosity of the active energy ray-polymerizable resin composition can be adjusted by adding water, or the viscosity can be reduced by heating the active energy ray-polymerizable resin composition.

The film thickness of the resin composition layer formed from the active energy ray-polymerizable resin composition of the present invention is not particularly limited and can be adjusted appropriately depending on the intended use. Adjustment of the viscosity and coating of the resin composition according to these embodiments can be easily carried out by adding a solvent to the active energy ray-polymerizable resin composition as needed.

When the resin composition layer has a thickness of 0.1 to 6 μm, the viscosity is preferably 1 to 1500 mPa·s, more preferably 10 to 1300 mPa·s, and even more preferably 20 to 1000 mPa·s. If the viscosity is 1500 mPa·s or less, when applied to the substrate (F), a thin film coating of 0.1 to 6 μm is possible, and optical properties such as transmittance are also excellent. On the other hand, a viscosity of 1 mPa·s or less is preferred because it makes it easier to control the thickness of the resin composition layer.

Furthermore, when the resin composition layer has a thickness of 6 to 300 μm, the viscosity is preferably 1500 to 100,000 mPa·s, and more preferably 3,000 to 50,000 mPa·s. The viscosity of the resin composition is significantly affected by the viscosity of the compound (Mb) having an α,β-ethylenically unsaturated double bond group with a mass average molecular weight of 1,000 to 60,000. Therefore, in order to control the viscosity of the resin composition, it is preferable to use a compound (Mb) with a viscosity of 1 to 100,000 mPa·s.

Next, the coating process of the active energy ray-polymerizable resin composition will be described.
The active energy ray-polymerizable resin composition can be applied to one or both surfaces of a substrate (F) described below by a suitable method according to a conventional method, and if necessary, another substrate can be laminated on the surface of the active energy ray-polymerizable resin composition to form a laminate. The required film thickness of the resin composition layer varies depending on the intended use.

When the resin composition is used in applications such as laminates for optical elements, such as hard coat films or polarizing films, as described below, the resin composition is applied as a thin film. The thickness of the resin composition layer formed by application is preferably 0.1 to 6 μm, and more preferably 0.1 to 3 μm. By making the thickness 0.1 μm or more, it becomes easier to obtain sufficient adhesion or adhesive strength when the resin composition is used as a coating agent or adhesive. On the other hand, if the thickness of the resin composition layer exceeds 6 μm, there is often no change in properties such as adhesion or adhesive strength.

When the resin composition is used in applications such as a laminate for optical elements, such as the decorative film (meaning a filler sheet for touch panels) described below, the resin composition is applied as a thick film. The thickness of the resin composition layer formed by coating is preferably 6 to 300 μm, and more preferably 20 to 250 μm. If the thickness is 6 μm or more, sufficient stress relaxation properties are obtained, and if it is 300 μm or less, deterioration of coating properties such as streaking can be suppressed.

There are no particular limitations on the method for applying the active energy ray-polymerizable resin composition of the present invention to a substrate or the like, and various coating methods such as those using a Mayer bar, applicator, brush, spray, roller, gravure coater, die coater, microgravure coater, lip coater, comma coater, curtain coater, knife coater, reverse coater, and spin coater can be used. Thin film coating, thick film coating, and other methods can be used depending on the application, and there are no particular limitations.

The active energy ray-polymerizable resin composition of the present invention is applied to a substrate by a known, conventional method, and the resulting coating layer is irradiated with active energy rays to polymerize the compound (K) having a cationically polymerizable group such as an oxirane group, thereby polymerizing and curing the composition. Suitable light sources for the active energy ray irradiation are those that primarily emit light in the 150 to 550 nm wavelength range, including low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, LED lamps, xenon lamps, and metal halide lamps. Laser beams, electron beams, and other types of active energy rays can also be used for exposure.

When an ultraviolet-absorbing substrate is used as the substrate (F), it is preferable to use a lamp in the ultraviolet irradiation device that irradiates a large amount of light at wavelengths longer than the absorption wavelength of the ultraviolet absorber contained in the protective film.
Examples of such lamps include the "D bulb," which has a high irradiation amount in the wavelength range of 380 to 400 nm, and the "V bulb," which has a high irradiation amount in the wavelength range of 405 to 425 nm, centered on the 420 nm range (both of these bulbs are UV lamps manufactured by Heraeus).

The amount of ultraviolet radiation to be applied is not particularly limited, but it is preferable to apply light having a wavelength of 320 to 390 nm (UV-A region) or 395 to 445 nm (UV-V region) and an illuminance of 1 to 3,000 mW/cm ² so that the exposure amount is 10 to 5,000 mJ/cm ^2. If the exposure amount is 10 mJ/cm ² or more, the curing of the active energy ray-polymerizable resin composition is promoted and the desired performance can be exhibited, while if the exposure amount is 10,000 mJ/cm ² or less, the exposure time is not too long and productivity is excellent.

<<Laminate>>
Next, a laminate obtained by laminating the active energy ray-polymerizable resin composition of the present invention on one or both sides of a substrate (F) will be described.
The laminate of the present invention can also be suitably used as a laminate for an optical element.
Furthermore, by using the active energy ray-polymerizable resin composition of the present invention, even when an ultraviolet-absorbing substrate is used as at least one of the substrates (F) in a laminate including a first substrate (F), a resin composition layer, and a second substrate (F) in this order, or even when both the first substrate (F) and the second substrate (F) are ultraviolet-absorbing substrates, a laminate having excellent adhesion, moist heat resistance, and flex resistance can be obtained.

When the active energy ray-polymerizable resin composition of the present invention is used in a polymerization reaction using active energy rays, it is preferable that the substrate (F) be a transparent film-like substrate (transparent film) and that the resin composition layer be formed on at least one surface of the transparent film.

The transparent film laminate can be obtained as follows.
A laminate can be obtained by coating one side of a transparent film with the active energy ray-polymerizable resin composition of the present invention and laminating another transparent film on the surface of the resin composition layer, or by further coating one or both sides of this laminate with the active energy ray-polymerizable resin composition and further laminating it on another transparent film, glass, or a transparent molded body.

The active energy ray polymerization reaction of the active energy ray-polymerizable resin composition proceeds by irradiating the composition with active energy rays when coating or laminating the composition, or even after lamination. However, it is preferable to irradiate the composition with active energy rays after lamination to proceed with the polymerization reaction.

<Base material (F)>
As the substrate (F), a film-like substrate, a glass plate, a paper processed product, etc. can be used without any particular limitation.On the other hand, when used as an adhesive for bonding two or more substrates (F), in order to irradiate with active energy rays and polymerize, it is necessary to use a substrate that is easy to transmit active energy rays, and it is particularly preferable to use a transparent film or a transparent glass plate.Even if one of the substrates is one that is difficult to transmit active energy rays, such as wood, a metal plate, a plastic plate, a paper processed product, etc., it can be used by using a transparent film or a transparent glass plate as the other, and irradiating from the transparent film or transparent glass plate side to carry out polymerization and curing.

As the substrate (F), it is preferable to use a film substrate, and examples of such transparent film substrates (transparent films) include cellophane and various plastic films, with various plastic films being preferred. The film substrate may be a single layer, or a multilayer structure formed by laminating multiple substrates can also be used.

When transparent films are used in a multilayer structure, they may be of the same or different compositions. For example, a polycycloolefin film may be used on one side and a polyacrylic film on the other side.
The thickness of the transparent film can be determined as appropriate, but is generally about 1 to 500 μm from the viewpoints of strength, workability such as handleability, thinness, etc. In particular, a thickness of 1 to 300 μm is preferred, and a thickness of 5 to 200 μm is more preferred. A transparent film thickness of 5 to 150 μm is particularly suitable.

In addition, the transparent film can be used as an optical film for information and communication devices such as displays and touch panels.

Of the various types of transparent films, those primarily used for optical applications are preferred as optical films. Here, optical films are transparent films that have been specially treated, and those that have optical functions (such as light transmission, light diffusion, light collection, refraction, scattering, and haze) are called optical films. These optical films can be used alone or in combination.

The various transparent films used as optical films are made from thermoplastic resins that offer excellent transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy. These transparent films, also known as plastic films or plastic sheets, include polyvinyl alcohol films, polytriacetylcellulose films, polyolefin films such as polypropylene, polyethylene, polycycloolefin, and ethylene-vinyl acetate copolymer, polyester films such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate films, polynorbornene films, polyarylate films, polyacrylic films, polyphenylene sulfide films, polystyrene films, polyvinyl films, polyamide films, polyimide films, and polyoxirane films.

<Laminate for optical element>
In one embodiment of the present invention, a laminate for optical elements can be constructed by forming a resin composition layer comprising the active energy ray-polymerizable resin composition of the present invention on at least one main surface of an optical film as the substrate (F).

Laminates for optical elements are used by being attached to glass plates of liquid crystal display devices, PDP modules, touch panel modules, organic EL modules, etc., or transparent films such as the various plastic films mentioned above.

The basic layer structure of the laminate for optical elements is a sheet-like double-sided active energy ray-polymerizable resin composition laminate such as transparent film/resin layer/transparent film or transparent film/resin layer/transparent film/resin layer/transparent film.Furthermore, the laminate is used as a laminate for optical elements in which a multilayer optical film such as transparent film/resin layer/transparent film/resin layer/transparent film/resin layer/transparent film, glass, or an optical molded product is fixed to an optical member.
Any of these transparent films is at least an optical film.

Specific examples of laminates for optical elements include hard coat films, antistatic coat films, antiglare coat films, polarizing films, retardation films, elliptically polarizing films, antireflection films, light diffusion films, brightness enhancement films, prism films (also called prism sheets), decorative films (meaning filling sheets for touch panels), and light guide films (also called light guide plates). The resin composition of the present invention may be used as an adhesive to further adhere the laminates for optical elements to glass plates of liquid crystal displays, PDP modules, touch panel modules, organic EL modules, and the like. Alternatively, the resin composition of the present invention may be used as an adhesive to adhere the laminates for optical elements to the various optical films listed above.

Hereinafter, a polarizing film will be used as an example of a laminate for optical elements, and an embodiment of the laminate will be described in more detail. A polarizing film, also known as a polarizing plate, is a multilayered sheet-like laminate for optical elements in which two polyacetyl cellulose-based films, such as polytriacetyl cellulose-based protective films (hereinafter referred to as "TAC films"), are laminated on both sides of a polyvinyl alcohol-based polarizer, or one or both sides of a polyvinyl alcohol-based polarizer are laminated with a polynorbornene-based film, such as a polycycloolefin-based film, a polyacrylic film, a polycarbonate film, or a polyester film, via an adhesive. The active energy ray-polymerizable resin composition of the present invention can be suitably used as the adhesive for polarizing films.

When transparent protective films are provided on both sides of the polarizer, the transparent protective films on the front and back may be made of the same polymer material, or transparent films made of different polymer materials may be used.

Preferred protective films for use in polarizing plates (polarizing films) include TAC films, polycycloolefin films, polyacrylic films, polycarbonate films, and polyester films. A UV-absorbing substrate containing a UV absorber can also be used for the protective film. A substrate that absorbs most of the UV light of 400 nm or less is used as the UV-absorbing substrate. When the laminate of the present invention is a polarizing plate, at least one of the two protective films may be a UV-absorbing substrate.

More specifically, a polarizing plate (polarizing film) using the active energy ray-polymerizable resin composition of the present invention can be obtained as follows.

(I) An active energy ray-polymerizable resin composition is applied to one surface of a transparent protective film as a first substrate (F) to form a first resin composition layer;
an active energy ray-polymerizable resin composition is applied to one surface of a second transparent protective film as a second substrate (F) to form a second resin composition layer;
Next, a first resin composition layer and a second resin composition layer are superimposed simultaneously and/or sequentially on each surface of the polyvinyl alcohol-based polarizer, and then the layers are irradiated with active energy rays to polymerize and cure the first resin composition layer and the second resin composition layer.

(II) A production method in which an active energy ray-polymerizable resin composition is applied to one surface of a polyvinyl alcohol-based polarizer to form a first resin composition layer, the surface of the formed first resin composition layer is covered with a first transparent protective film serving as a first substrate (F), and then an active energy ray-polymerizable resin composition is applied to the other surface of the polyvinyl alcohol-based polarizer to form a second resin composition layer, the surface of the formed second resin composition layer is covered with a second transparent protective film serving as a second substrate (F), and active energy rays are irradiated to polymerize and cure the first polymerizable resin composition layer and the second resin composition layer.

(III) A method for producing a film includes, but is not limited to, dropping an active energy ray-polymerizable resin composition onto an end portion of a first substrate (F) where a first transparent protective film and a polyvinyl alcohol-based polarizer are superposed, and onto an end portion of a second transparent protective film (F) superposed on the side of the polyvinyl alcohol-based polarizer where the first transparent protective film is not present, passing the film between rolls to spread the resin composition between the layers, and then irradiating the film with active energy rays to polymerize and cure the active energy ray-polymerizable resin composition.

Specific examples of the present invention will be described below together with comparative examples, but the present invention is not limited to the following examples. In the following examples and comparative examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively, and "RH" represents relative humidity.
The blend amounts in the table are in parts by mass, and values other than the solvent are calculated as non-volatile content. Note that blank spaces in the table indicate that no blend was made.

<Method for measuring mass average molecular weight>
The "mass average molecular weight" is a value measured using a gel permeation chromatography "HLC-8220GPC" manufactured by Tosoh Corporation, and is a polystyrene-equivalent mass average molecular weight measured at a flow rate of 0.6 ml/min using four separation columns: "TSK-GEL SUPER H5000,""TSK-GEL SUPER H4000,""TSK-GEL SUPER H3000," and "TSK-GEL SUPER H2000" manufactured by Tosoh Corporation connected in series, and using tetrahydrofuran at a temperature of 40°C as the mobile phase.

<Method for measuring hydroxyl value>
The hydroxyl value was measured as follows. Approximately 1 g of sample was precisely weighed into a stoppered Erlenmeyer flask, and 100 ml of a toluene/ethanol (volume ratio: toluene/ethanol = 2/1) mixture was added and dissolved. Then, exactly 5 ml of an acetylating agent (a solution prepared by dissolving 25 g of acetic anhydride in pyridine to a volume of 100 ml) was added and stirred for approximately 1 hour. Phenolphthalein test solution was added as an indicator and the mixture was stirred for 30 seconds. The solution was then titrated with 0.1 N alcoholic potassium hydroxide solution until it turned pale pink, and the hydroxyl value was calculated using the following formula. The hydroxyl value was the value for the resin in its dry state (unit: mg KOH/g).
Hydroxyl value (mg KOH/g) = [{(b - a) x F x 28.25}/S]/(non-volatile content/100) + D
where S is the amount of sample collected (g).
a: Amount of 0.1N alcoholic potassium hydroxide solution consumed (ml)
b: Amount of 0.1N alcoholic potassium hydroxide solution consumed in the blank experiment (ml)
F: Potency of 0.1N alcoholic potassium hydroxide solution
D: Acid value (mgKOH/g)

The materials used in the examples and comparative examples are as follows.
<Cationically polymerizable compound (K)>
[Oxirane compound (K1)]
((K11) Oxirane Compound Having No Alkoxysilyl Group)
"(K111) Oxirane compound having an aromatic ring and no alkoxysilyl group"
JER828: Bisphenol A diglycidyl ether (manufactured by Mitsubishi Chemical Corporation)
"(K112) Oxirane compound having no aromatic ring or alkoxysilyl group"
16HDDGE: 1,6-hexanediol diglycidyl ether CEL2021P: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Celloxide 2021P, manufactured by Daicel Corporation)
((K12) Oxirane Compound Having an Alkoxysilyl Group)
KBE-402: 3-glycidoxypropylmethyldiethoxysilane (Shin-Etsu Chemical Co., Ltd.)
[Cyclic hetero compounds other than oxirane compounds (K2)]
OXT-101: 3-ethyl-3-hydroxymethyloxetane (Aronoxetane OXT-101, manufactured by Toagosei Co., Ltd.)

<Sulfide Compound (S)>
[Sulfide compound having an aromatic ring (S1)]
((S11) Sulfide Compound Having an Aromatic Ring and No Nitrogen Atom)
Irganox 1035: 2,2'-thiodiethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (manufactured by BASF)
Irganox 1520: 2,4-bis(octylthiomethyl)-6-methylphenol (manufactured by BASF)
Irganox 1726: 2,4-bis[(dodecylthio)methyl]-6-methylphenol (manufactured by BASF)
((S12) Sulfide Compound Having an Aromatic Ring and a Nitrogen Atom)
Omnirad 907: 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane (manufactured by IGM resins B.V.)
OXE01: 1-[4-(phenylthio)phenyl]octane-1,2-dione 2-(O-benzoyloxime) (manufactured by BASF, Irgacure OXE01)
[Sulfide compound (S2) having no aromatic ring]
AO-412S: 2,2-bis[[3-(dodecylthio)-1-oxopropyloxy]methyl]-1,3-propanediyl bis[3-(dodecylthio)propionic acid] (manufactured by ADEKA Corporation, Adeka Stab AO-412S)
AO-503: Ditridecyl 3,3'-thiobispropionate (ADEKA Corporation, Adekastab AO-503)

<Acid Generator (KE)>
[Iodonium salt-based acid generator (KE1)]
Omnicat 250: 4-isobutylphenyl (4-methylphenyl)
Hexafluorophosphate (manufactured by IGM resins B.V.)
WPI-124: bis[4-n-alkyl(C10-13)phenyl]iodonium tetrakispentafluorophenylborate (Fujifilm Wako Pure Chemical Industries, Ltd.)
[Sulfonium salt acid generator (KE2)]
CPI-110P: San-Apro triarylsulfonium PF6 salt type photoacid generator CPI-101A: San-Apro triarylsulfonium SbF6 salt type photoacid generator

<Thioxanthone Compound (T)>
DETX-S: 2,4-diethylthioxanthone 2-ITX: 2-isopropylthioxanthone <radical polymerization initiator (E)>
TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Omnirad TPO manufactured by IGM resins B.V.)

<Compound (M) Having an α,β-Ethylenically Unsaturated Double Bond Group>
[Compound (Ma)]
(Compound (Ma1))
4HBA: 4-hydroxybutyl acrylate CHDMMA: cyclohexanedimethanol monomethacrylate (compound (Ma2))
IBXA: isobornyl acrylate TCDDA: tricyclodecane dimethanol diacrylate (compound (Ma3))
EOEOEA: Ethoxyethoxyethyl acrylate DPGDA: Dipropylene glycol diacrylate TMPTA: Trimethylolpropane triacrylate

[Compound (Mb)]
(Compound (Mb1))
Oligomer 1: Shikou UV3000B: Polyurethane acrylate manufactured by Nippon Synthetic Chemical Industry Co., Ltd., Mw=18,000
Oligomer 2: An oligomer produced by the following method was used.
(Compound (Mb3))
Oligomer 3: An oligomer prepared by the following method was used.

<Production of Oligomer 2>
A five-neck separable flask equipped with a stirrer, reflux condenser, gas inlet tube, thermometer, and dropping funnel was charged with 81.6 parts of polytetramethylene glycol (PTG850 manufactured by Hodogaya Chemical Co., Ltd., hydroxyl value 127.1 mgKOH/g) and 41.4 parts of isophorone diisocyanate, and the temperature was raised to 60°C while introducing dry air. 0.05 parts of dibutyltin dilaurate was added thereto, and the mixture was allowed to react for 1 hour. Separately, 27.0 parts of 4-hydroxybutyl acrylate and 0.15 parts of hydroquinone monomethyl ether were charged to a dropping funnel, and the mixture was added dropwise to the separable flask over 1 hour. After the dropwise addition was completed, stirring was continued for 3 hours at 80°C, and the absence of an isocyanato group absorption peak was confirmed by infrared absorption spectroscopy, and the reaction was terminated to obtain Oligomer 2. The mass-average molecular weight of the product was 4,000.

<Production of Oligomer 3>
A five-neck separable flask equipped with a stirrer, reflux condenser, gas inlet tube, and thermometer was charged with 96.9 parts of bisphenol F epoxy resin (Mitsubishi Chemical Corporation: JER1007P, epoxy equivalent 2250), 3.2 parts of acrylic acid, 0.1 parts of hydroquinone monomethyl ether, and 20 parts of MEK, and the mixture was heated to 60°C while introducing dry air to dissolve. To this mixture, 0.5 parts of tetrabutylammonium borate was added, and the mixture was heated to 100°C and reacted for 8 hours to obtain Oligomer 3. The mass average molecular weight of Oligomer 3 was 5100.

[Example 1]
50 parts of JER828 as a cationically polymerizable compound (K), 45.5 parts of 16HDDGE, 0.5 parts of Irganox 1035 as a sulfide compound (S), 3 parts of Omnicat 250 as an acid generator (KE), and 1 part of DETX as a thioxanthone compound (T) were charged into a light-shielded 300 ml glass bottle, thoroughly stirred with a disper, and then thoroughly degassed, to obtain an active energy ray-polymerizable resin composition.

[Examples 2 to 30, Comparative Examples 1 to 5]
Active energy ray-polymerizable resin compositions were obtained in the same manner as in Example 1, except that the compositions and blending amounts (parts by mass) were changed as shown in Tables 1 to 3.

Evaluation of active energy ray-polymerizable resin composition
The storage stability of the active energy ray-polymerizable resin composition of the present invention at high temperature (70° C.) was evaluated by the following method. The results are shown in Tables 1 to 3.

<High temperature storage stability>
The active energy ray-polymerizable resin composition was stored in a thermostatic bath at 70°C for 24 hours, and 1.1 ml of the resin composition before and after storage was used as a measurement sample. Measurement was performed using an E-type viscometer (TVE-33LT, manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 5 rpm and 25°C, and the viscosity was evaluated based on the rate of change in viscosity.
Viscosity change rate = viscosity after storage / viscosity before storage [evaluation criteria]
◎: 0.95 or more and less than 1.05, very excellent ○: 1.05 or more and less than 1.1, or 0.9 or more and less than 0.95, excellent △: 1.1 or more and less than 1.15, or 0.85 or more and less than 0.9, practically acceptable ×: 1.15 or more, or less than 0.85, not practically applicable

Evaluation of laminates
The obtained active energy ray-polymerizable resin composition was used to prepare the following laminates X1 and X2, which were then evaluated by the following methods. The results are shown in Tables 1 to 3.

<Production of Laminate X1 (Polarizing Plate)>
The transparent films (1) and (2) were UV-absorbing substrates, including UV-absorber-containing polytriacetylcellulose (TAC) films manufactured by Fujifilm Corporation (trade name "Fujitac: 80 μm," with a transmittance of 20% or less at wavelengths of 300 to 380 nm). Each film surface was subjected to a corona treatment at a discharge rate of 300 W·min/ ^m². Within one hour of the surface treatment, the resulting active energy ray-polymerizable resin composition was applied to a film thickness of 4 μm using a wire bar coater to form a resin composition layer. The polyvinyl alcohol-based polarizer described above was sandwiched between the resin composition layer and the transparent film (1) (UV-absorbing TAC film) to obtain a laminate consisting of "transparent film (1) (UV-absorbing TAC film)/resin composition layer/PVA-based polarizer/resin composition layer/transparent film (2) UV-absorbing TAC film." The four sides of this laminate were secured to the tinplate with cellophane tape, so that the transparent film (2) was in contact with the tinplate. The transparent film (1) was irradiated with ultraviolet light (UV-V region) at a maximum illuminance of 500 mW/cm ² and an accumulated light quantity of 1000 mJ/cm ² using an ultraviolet irradiation device (Heraeus V-bulb) to produce a laminate X1 (polarizing plate).

<Production of laminate X2>
The obtained active energy ray-polymerizable resin composition was heated to 100°C and then coated to a thickness of 8 μm using a bar coater on a 50 μm thick polyethylene terephthalate (hereinafter abbreviated as PET) film having a transmittance of 20% T or less in the wavelength range of 300 to 380 nm. A 50 μm thick PET film was then bonded to this using nip rolls to obtain a laminate consisting of "transparent film (1) (PET film)/resin composition layer/transparent film (2) (PET film)". After that, ultraviolet light was irradiated from one side using an ultraviolet irradiation device (V-bulb manufactured by Heraeus) at a maximum illuminance of 500 mW/cm ² and an accumulated light amount of 1000 mJ/cm ² to obtain laminate X2.

For each, laminate X1 and laminate X2 produced using the active energy ray-polymerizable resin composition immediately after production were used for evaluation as "initial." Furthermore, laminate X1 and laminate X2 produced using the active energy ray-polymerizable resin composition after storage at 70°C for 24 hours were used for evaluation as "after storage (70°C for 24 hours)."

<Adhesive force>
The adhesive strength was measured in accordance with JIS K6 854-4 Adhesives - Peel Adhesion Strength Test Method - Part 4: Floating Roller Method.
That is, the obtained laminate X1 was cut into a size of 25 mm × 150 mm using a cutter to prepare a measurement sample. The sample was attached to a metal plate using a double-sided adhesive tape (DF8712S manufactured by Toyochem Co., Ltd.) and a laminator to obtain a measurement laminate of a polarizing plate and a metal plate. A peeling trigger was previously provided between the transparent film and the polarizer in the polarizing plate of the measurement laminate. This measurement laminate was peeled at a 90° angle at a rate of 300 mm/min under conditions of 23°C and 50% relative humidity, and the peel strength was measured. At this time, the peel strength between the polyvinyl alcohol-based polarizer and the transparent film (2) was measured. This peel strength was evaluated as adhesive strength using a four-point scale.
[Evaluation criteria]
◎: Peeling not possible, or polarizing plate broken, very good ○: Peeling strength is 2.0 (N/25 mm) or more, excellent △: Peeling strength is 1.0 (N/25 mm) or more and less than 2.0 (N/25 mm), usable ×: Peeling strength is less than 1.0 (N/25 mm), not usable

<Moisture and heat resistance>
The laminate X2 bonded with each adhesive was cut into a size of 50 mm x 40 mm and exposed for 1000 hours under conditions of a temperature of 60°C and 90% RH and a temperature of 85°C and 85% RH. After exposure, the presence or absence of peeling at the edge of the laminate A was visually evaluated using the following four-point scale.
If peeling occurred under the conditions of 85° C. and 85% RH, it was rated as ×, △, or ◯.
[Evaluation criteria]
◎: No peeling even under conditions of 85°C and 85% RH, very excellent ○: No peeling even under conditions of 60°C and 90% RH, excellent △: Peeling of less than 1 mm occurred under conditions of 60°C and 90% RH, usable ×: Peeling of 1 mm or more occurred under conditions of 60°C and 90% RH, not usable

<Bending resistance>
The laminate X2 was cut into a size of 120 mm wide x 200 mm long, and the bending tester (manufactured by Yuasa System Co., Ltd.) was set so that the inner diameter (diameter) when bent was 2 mm, and the bending test was repeated 300,000 times, with one cycle consisting of bending and releasing 180°. The flexibility was evaluated by observing the appearance after the test from the following perspectives.
Appearance: The test laminate was visually inspected for the presence of bubbles and the presence or absence of lifting or peeling of the resin composition layer under the following conditions.
[Evaluation criteria]
◎: No bubbles, lifting or peeling was observed, and it was very excellent. ○: Some bubbles, lifting or peeling was observed, but it was excellent. △: Some bubbles, lifting or peeling was observed, but it was usable. ×: Significant bubbles, lifting or peeling was observed, and it was not usable.

[Example 41]
50 parts of JER828 as a cationically polymerizable compound (K), 46 parts of 16HDDGE, 0.5 parts of Irganox 1035 as a sulfide compound (S), and 4 parts of CPI-110P as an acid generator (KE) were charged into a light-shielded 300 ml glass bottle, thoroughly stirred with a disper, and then thoroughly degassed, to obtain an active energy ray-polymerizable resin composition.

[Examples 42 to 54, Comparative Examples 6 to 10]
As shown in Tables 4 and 5, active energy ray-polymerizable resin compositions were obtained in the same manner as in Example 41, except that the compositions and blending amounts (parts by mass) were changed.

Evaluation of active energy ray-polymerizable resin composition
The storage stability of the active energy ray-polymerizable resin composition of the present invention at high temperatures (70° C. or 100° C.) was evaluated by the following method. The results are shown in Tables 4 and 5.

<High temperature storage stability>
The active energy ray-polymerizable resin composition was stored in a thermostatic chamber at 70°C or 100°C for 24 hours, and 1.1 ml of the resin composition before and after storage was used as a measurement sample. Measurement was performed using an E-type viscometer (TVE-33LT, manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 5 rpm and 25°C, and the viscosity was evaluated based on the rate of change in viscosity.
Viscosity change rate = viscosity after storage / viscosity before storage [evaluation criteria]
◎: 0.95 or more and less than 1.05, very excellent ○: 1.05 or more and less than 1.1, or 0.9 or more and less than 0.95, excellent △: 1.1 or more and less than 1.15, or 0.85 or more and less than 0.9, practically acceptable ×: 1.15 or more, or less than 0.85, not practically applicable

Evaluation of laminates
The obtained active energy ray-polymerizable resin composition was used to prepare the following laminate Y1, and the laminate was evaluated by the following methods. The results are shown in Tables 4 and 5.

<Production Example of Laminate Y1 (Polarizing Plate)>
The transparent film (1) was a polytriacetyl cellulose film (trade name "Fujitack: 80 μm") manufactured by Fujifilm Corporation that did not contain an ultraviolet absorber, and the transparent film (2) was a polytriacetyl cellulose film (trade name "Fujitack: 80 μm", with a transmittance of 20% or less at wavelengths of 300 to 380 nm) manufactured by Fujifilm Corporation. Each film surface was subjected to a corona treatment at a discharge rate of 300 W·min/ ^m². Within one hour after the surface treatment, the resulting active energy ray-polymerizable resin composition was applied to a film thickness of 4 μm using a wire bar coater to form a resin composition layer. The polyvinyl alcohol-based polarizer described above was sandwiched between the resin composition layer and the transparent film (1) (TAC film) to obtain a laminate consisting of "transparent film (1) (TAC film) / resin composition layer / PVA-based polarizer / resin composition layer / transparent film (2) (ultraviolet-absorbing TAC film)." The four sides of this laminate were fixed with cellophane tape so that the transparent film (2) was in contact with the tinplate. The transparent film (1) was irradiated with ultraviolet light (UV-A region) at a maximum illuminance of 400 mW/cm ² and an accumulated light quantity of 600 mJ/cm ² using an ultraviolet irradiation device (D-bulb manufactured by Heraeus) to produce a laminate Y1 (polarizing plate).

<Production of laminate Y2>
The obtained active energy ray-polymerizable resin composition was heated to 100°C and then coated to a thickness of 8 μm using a bar coater on a 50 μm thick PET film having a transmittance of 20% T or less in the wavelength range of 300 to 380 nm. A 50 μm thick PET film was then bonded to this using nip rolls to obtain a laminate consisting of "transparent film (1) (PET film)/resin composition layer/transparent film (2) (PET film)", and then irradiated from one side with ultraviolet light at a maximum illuminance of 500 mW/cm ² and an accumulated light amount of 1000 mJ/cm ² using an ultraviolet irradiation device (V-bulb manufactured by Heraeus) to obtain laminate Y2.

For each, laminate Y1 and laminate Y2 produced using the active energy ray-polymerizable resin composition immediately after production were used for evaluation as "initial." Furthermore, laminate Y1 and laminate Y2 produced using the active energy ray-polymerizable resin composition after storage at 100°C for 24 hours were used for evaluation as "after storage (100°C for 24 hours)."

<Adhesive force>
The adhesive strength was measured in accordance with JIS K6 854-4 Adhesives - Peel Adhesion Strength Test Method - Part 4: Floating Roller Method.
That is, the obtained laminate Y1 was cut into a size of 25 mm x 150 mm using a cutter to prepare a measurement sample. The sample was attached to a metal plate using a double-sided adhesive tape (DF8712S manufactured by Toyochem Co., Ltd.) and a laminator to obtain a measurement laminate of a polarizing plate and a metal plate. A peeling trigger was previously provided between the transparent film and the polarizer in the measurement laminate. This measurement laminate was peeled at a 90° angle at a rate of 300 mm/min under conditions of 23°C and 50% relative humidity, and the peel strength was measured. The peel strength between the polyvinyl alcohol-based polarizer and the transparent film (2) was measured. This peel strength was evaluated as adhesive strength using a four-point scale.
[Evaluation criteria]
◎: Peeling not possible, or polarizing plate broken, very good ○: Peeling strength is 2.0 (N/25 mm) or more, excellent △: Peeling strength is 1.0 (N/25 mm) or more and less than 2.0 (N/25 mm), usable ×: Peeling strength is less than 1.0 (N/25 mm), not usable

<Moisture and heat resistance>
The laminate A bonded with each adhesive was cut into a size of 50 mm x 40 mm and exposed for 1000 hours under conditions of a temperature of 60°C and 90% RH and a temperature of 85°C and 85% RH. After exposure, the laminate Y1 was visually inspected for peeling at the edge and evaluated using the following four-point scale.
If peeling occurred under the conditions of 85° C. and 85% RH, it was rated as ×, △, or ◯.
[Evaluation criteria]
◎: No peeling even under conditions of 85°C and 85% RH, very excellent ○: No peeling even under conditions of 60°C and 90% RH, excellent △: Peeling of less than 1 mm occurred under conditions of 60°C and 90% RH, usable ×: Peeling of 1 mm or more occurred under conditions of 60°C and 90% RH, not usable

<Bending resistance>
The laminate Y2 was cut into a size of 120 mm wide x 200 mm long, and the conditions were set so that the inner diameter (diameter) when bent would be 2 mm using a bending tester (manufactured by Yuasa System Co., Ltd.), and the bending test was repeated 300,000 times, with one cycle consisting of bending and releasing 180°. The flexibility was evaluated by observing the appearance after the test from the following perspectives.
Appearance: The test laminate was visually inspected for the presence of bubbles and the presence or absence of lifting or peeling of the resin composition layer under the following conditions.
[Evaluation criteria]
◎: No bubbles, lifting or peeling was observed, and it was very excellent. ○: Some bubbles, lifting or peeling was observed, but it was excellent. △: Some bubbles, lifting or peeling was observed, but it was usable. ×: Significant bubbles, lifting or peeling was observed, and it was not usable.

As shown in Tables 1 to 5, it was confirmed that the active energy ray-polymerizable resin composition of the present invention has excellent storage stability, high heat resistance, and excellent curability.
Furthermore, it was confirmed that the active energy ray-polymerizable resin composition has high heat resistance, and therefore has good adhesiveness, moist heat resistance, and bending resistance even when stored at high temperatures.

Claims (13)

An active energy ray-polymerizable resin composition comprising 1 to 99 mass% of a cationically polymerizable compound (K), 0.01 to 10 mass% of a sulfide compound (S) (excluding a thioxanthone compound (T) and a sulfonium salt-based acid generator (KE2)), an acid generator (KE), a compound (M) having an α,β-ethylenically unsaturated double bond group, and a radical polymerization initiator (E), wherein the sulfide compound (S) is a sulfide compound (S111) having one phenol structure in one molecule , and the cationically polymerizable compound (K) is a cationically polymerizable compound (K1) that is an oxirane compound that is a three-membered cyclic ether compound .

The active energy ray-polymerizable resin composition according to claim 1, wherein the acid generator (KE) is an iodonium salt-based acid generator (KE1). The active energy ray-polymerizable resin composition according to claim 1, wherein the acid generator (KE) is a sulfonium salt-based acid generator (KE2). The active energy ray-polymerizable resin composition according to any one of claims 1 to 3 , further comprising a thioxanthone compound (T). The active-energy ray-polymerizable resin composition according to any one of claims 1 to 4, wherein the compound (M) having an α,β-ethylenically unsaturated double bond group has a mass-average molecular weight of less than 1000 and includes a compound (Ma1) having a hydroxyl group and an α,β-ethylenically unsaturated double bond group. The active-energy ray-polymerizable resin composition according to any one of claims 1 to 5, wherein the compound (M) having an α,β-ethylenically unsaturated double bond group includes a compound (Mb) having an α,β-ethylenically unsaturated double bond group having a mass average molecular weight of 1,000 or more and 60,000 or less. The active-energy ray-polymerizable resin composition according to any one of claims 1 to 6, wherein the compound (M) having an α,β-ethylenically unsaturated double bond group has a mass-average molecular weight of less than 1000 and includes a compound (Ma2) having two or more α,β-ethylenically unsaturated double bond groups and at least one of a cycloalkane skeleton and a cycloalkene skeleton. The active energy ray-polymerizable resin composition according to any one of claims 1 to 7 , which is an adhesive. A laminate obtained by laminating a resin composition layer made of the active energy ray-polymerizable resin composition according to any one of claims 1 to 8 on one or both sides of a substrate (F). 10. The laminate according to claim 9 , wherein the substrate (F) is a polyacetyl cellulose film, a polynorbornene film, a polypropylene film, a polyacrylic film, a polycarbonate film, a polyester film, a polyvinyl alcohol film, or a polyimide film. A laminate comprising, in this order, a first substrate (F), a resin composition layer made of the active-energy ray-polymerizable resin composition according to any one of claims 1 to 8 , and a second substrate (F), wherein at least one of the substrates (F) is an ultraviolet-absorbing substrate, and the ultraviolet-absorbing substrate is a substrate having a transmittance of 20% or less at a wavelength of 300 to 380 nm . The laminate according to claim 11 , wherein both the first substrate (F) and the second substrate (F) are the ultraviolet absorbing substrate. The laminate according to any one of claims 9 to 12 , which is used for an optical element.