Active energy ray-curable composition and cured product

Abstract

To provide an active energy ray-curable composition which gives a cured product low in water absorption rate and excellent in both elongation and elastic modulus.SOLUTION: The active energy ray-curable composition contains a (meth)acrylate (A) having an alicyclic skeleton, an N-substituted (meth)acrylamide (B), an α-(allyloxymethyl) acrylate (C), a (meth)acrylate (D) having a urethane group, and a photopolymerization initiator (E). (D) is a urethane (meth)acrylate containing a polyol (a), a polyisocyanate (b), and an active hydrogen group-containing (meth)acrylate (c) as constituent raw materials. The active energy ray-curable composition contains 20-70 wt.% of (A), 5-40 wt.% of (B), 5-30 wt.% of (C), 10-40 wt.% of (D), and 2-10 wt.% of (E) based on the total weight of (A), (B), (C) and (D).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an active energy ray curable composition and a cured product thereof.

Background Art

[0002] Conventionally, a cured product of an active energy ray curable composition has been used as a material for displays such as organic EL displays (see, for example, Patent Documents 1 and 2). In recent years, as such a display, a so-called flexible display that can be bent has been developed. Along with this, materials for displays are required to have bend resistance characteristics that do not break when bent. However, in the cured product of the conventional active energy ray curable composition, the bend resistance characteristics are insufficient, and in order to realize sufficient bend resistance characteristics, it has been required that elongation and elastic modulus can be achieved at a high level simultaneously. In addition, the cured product itself may deteriorate due to water absorption and moisture absorption, and a low water absorption rate is also required.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide an active energy ray curable composition that gives a cured product having a low water absorption rate and excellent elongation and elastic modulus.

Means for Solving the Problems

[0005] As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. That is, the present invention is an active energy ray-curable composition containing an alicyclic skeleton-containing (meth)acrylate (A), an N-substituted (meth)acrylamide (B), an α-(allyloxymethyl)acrylate (C) represented by the following general formula (1), a (meth)acrylate (D) having a urethane group, and a photopolymerization initiator (E), wherein the (meth)acrylate (D) having a urethane group is a urethane (meth)acrylate containing a polyol (a), a polyisocyanate (b), and an active hydrogen group-containing (meth)acrylate (c) as constituent raw materials, Based on the total weight of the alicyclic skeleton-containing (meth)acrylate (A), the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl)acrylate (C) represented by the general formula (1), and the (meth)acrylate (D) having a urethane group, the alicyclic skeleton-containing (meth)acrylate (A) is 20% to 70% by weight, the N-substituted (meth)acrylamide (B) is 5% to 40% by weight, the α-(allyloxymethyl)acrylate (C) represented by the general formula (1) is 5% to 30% by weight, the (meth)acrylate (D) having a urethane group is 10% to 40% by weight, and the photopolymerization initiator (E) is 2% to 10% by weight; a cured product obtained by curing the active energy ray-curable composition.

[0006] [Chemical formula] [In formula (1), R 1 represents a hydrogen atom or an organic group having 1 to 30 carbon atoms. R 2 , R 3 , R 4 , R 5 and R 6 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.] [Advantages of the Invention]

[0007] The cured product of the active energy ray-curable composition of the present invention has the effect of having a low water absorption rate and excellent elongation and elastic modulus.

Embodiments for Carrying Out the Invention

[0008] The active energy ray-curable composition of the present invention contains a (meth)acrylate (A) having an alicyclic skeleton, an N-substituted (meth)acrylamide (B), an α-(allyloxymethyl)acrylate (C), a (meth)acrylate (D) having a urethane group, and a photopolymerization initiator (E). In the present invention, the notation “(meth)acrylate” means acrylate and / or methacrylate, the notation “(meth)acrylic” means acrylic and / or methacrylic, and the notation “(meth)acryloyl” means acryloyl and / or methacryloyl.

[0009] Examples of the (meth)acrylate (A) having an alicyclic skeleton include cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and adamantyl (meth)acrylate. Among the above (meth)acrylates (A) having an alicyclic skeleton, a monofunctional (meth)acrylate having an alicyclic skeleton is preferable from the viewpoints of elongation and elastic modulus of the cured product, a monofunctional (meth)acrylate having an alicyclic skeleton with 6 to 30 carbon atoms is more preferable, and isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, and trimethylcyclohexyl (meth)acrylate are particularly preferable.

[0010] In the present invention, the N-substituted (meth)acrylamide (B) means a compound in which one or two hydrogen atoms of the amino group of (meth)acrylamide are substituted with a substituent such as a hydrocarbon group, and examples of the N-substituted (meth)acrylamide include a chain amide having an N-(meth)acryloyl group and a cyclic amide having an N-(meth)acryloyl group.

[0011] Examples of the chain amide having an N-(meth)acryloyl group include N-alkyl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, N-hydroxyalkyl(meth)acrylamide, N-alkoxyalkyl(meth)acrylamide, and the like.

[0012] Examples of N-alkyl(meth)acrylamide include N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-dodecyl(meth)acrylamide, N-octadecyl(meth)acrylamide, and the like. From the viewpoint of the curability of the cured product, the number of carbon atoms of the alkyl group in N-alkyl(meth)acrylamide is preferably 1 to 20, more preferably 1 to 8, and particularly preferably 1 to 4.

[0013] Examples of N,N-dialkyl(meth)acrylamide include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N,N-diisobutyl(meth)acrylamide, N,N-di-tert-butyl(meth)acrylamide, N,N-diheptyl(meth)acrylamide, N,N-dioctyl(meth)acrylamide, N,N-di-tert-octyl(meth)acrylamide, N,N-didodecyl(meth)acrylamide, N,N-dioctadecyl(meth)acrylamide, and the like. The two alkyl groups of N,N-dialkyl(meth)acrylamide may be the same or different, and from the viewpoint of curability, the number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 8, and particularly preferably 1 to 4.

[0014] Examples of N-hydroxyalkyl (meth) acrylamide include N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, and N-(3-hydroxypropyl) (meth) acrylamide. From the viewpoint of curability, the number of carbon atoms in the alkylene group of N-hydroxyalkyl (meth) acrylamide is preferably 1 to 20, more preferably 1 to 8, and particularly preferably 1 to 4.

[0015] Examples of N-alkoxyalkyl (meth) acrylamide include N-n-butoxymethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide, N-butoxyethyl (meth) acrylamide, N-methoxypropyl (meth) acrylamide, N-ethoxypropyl (meth) acrylamide, N-methoxybutyl (meth) acrylamide, and N-ethoxybutyl (meth) acrylamide. From the viewpoint of curability, the number of carbon atoms in the alkoxyalkyl group of N-alkoxyalkyl (meth) acrylamide is preferably 2 to 20, more preferably 2 to 8, and particularly preferably 2 to 6. From the viewpoint of curability, the number of carbon atoms in the alkyl group of the alkoxyalkyl group is preferably 1 to 4, more preferably 1 to 3, and particularly preferably 1 to 2.

[0016] Examples of the cyclic amide having an N-(meth) acryloyl group include N-(meth) acryloylmorpholine, N-(meth) acryloylthiomorpholine, N-(meth) acryloylpiperidine, and N-(meth) acryloylpyrrolidine. From the viewpoint of curability, the number of carbon atoms in the cyclic amide having an N-(meth) acryloyl group is preferably 7 to 20, more preferably 7 to 18, and particularly preferably 7 to 16. In the present invention, these N-substituted (meth) acrylamides can be used alone or in combination of two or more. Among these, from the viewpoint of curability, N,N-dialkyl(meth)acrylamide, N-alkoxyalkyl(meth)acrylamide, and cyclic amides having an N-(meth)acryloyl group are preferred, more preferably N,N-dialkyl(meth)acrylamide and cyclic amides having an N-(meth)acryloyl group, and particularly preferably (meth)acryloylmorpholine, diethyl(meth)acrylamide, and dimethyl(meth)acrylamide.

[0017] In the present invention, α-(allyloxymethyl)acrylate (C) is α-(allyloxymethyl)acrylate represented by the following general formula (1).

[0018]

Chemical formula

[0019] In formula (1), R 1 represents a hydrogen atom or an organic group having 1 to 30 carbon atoms. R 2 , R 3 , R 4 , R 5 and R 6 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0020] R 2 , R 3 , R 4 , R 5 and R 6 When they are alkyl groups, the alkyl groups may be linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, a neopentyl group, a hexyl group, etc. may be mentioned.

[0021] A preferred embodiment of the α-(allyloxymethyl)acrylate (C) is a compound represented by the following general formula (2) in which R 5 and R 6 are hydrogen atoms, and a more preferred embodiment is R 2 , R 3 , R 4 , R5 and R 6 This is the case of α-(allyloxymethyl) acrylate in which all of them are hydrogen atoms.

[0022] [Chemical formula]

[0023] The above R 1 When the organic group has 1 to 30 carbon atoms, the organic group may be linear, branched or cyclic. From the viewpoint of extensibility, the preferred number of carbon atoms of the organic group is 1 to 18, more preferably 1 to 12, and still more preferably 1 to 8. Examples of the organic group include a hydrocarbon skeleton or an organic group composed of a hydrocarbon skeleton containing an ether bond.

[0024] Examples of the above hydrocarbon skeleton include a chain saturated hydrocarbon group (e.g., methyl group, ethyl group, propyl group, butyl group, amyl group, neopentyl group, hexyl group, octyl group, 2-ethylhexyl group, etc.), an alicyclic hydrocarbon group (e.g., cyclohexylmethyl group, isobornyl group, adamantyl group, dicyclopentanyl group, dicyclopentenyl group, etc.), and an aromatic hydrocarbon group (e.g., phenyl group, naphthyl group, anthranyl group, etc.). And these groups may have substituents. Preferably, it is a chain saturated hydrocarbon group that may have substituents.

[0025] Examples of the organic group composed of a hydrocarbon skeleton containing an ether bond include those having a structure in which an oxygen atom is inserted into at least one carbon-carbon bond constituting the above chain saturated hydrocarbon group (e.g., methyl group, ethyl group, propyl group, butyl group, amyl group, neopentyl group, hexyl group, octyl group, 2-ethylhexyl group, etc.), alicyclic hydrocarbon group (e.g., cyclohexylmethyl group, isobornyl group, adamantyl group, dicyclopentanyl group, dicyclopentenyl group, etc.), and aromatic hydrocarbon group (e.g., phenyl group, naphthyl group, anthranyl group, etc.).

[0026] Examples of the above substituents include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, cyano group, trimethylsilyl group, hydroxyl group and the like.

[0027] Examples of such organic groups include chain saturated hydrocarbon groups having an ether bond such as methoxyethyl group, methoxyethoxyethyl group and ethoxyethyl group; alicyclic hydrocarbon groups having a chain ether bond such as cyclohexyloxyethyl group and dicyclopentenyl oxyethyl group; araliphatic hydrocarbon groups having a chain ether bond such as phenoxyethyl group and phenoxyethoxyethyl group; cyclic ether groups such as glycidyl group, 3,4-epoxycyclohexylmethyl group, tetrahydrofuranyl group and tetrahydrofurfuryl group, but are not limited thereto.

[0028] Accordingly, specific examples of the α-(allyloxymethyl) acrylate compound include the following compounds. α-allyloxymethyl acrylic acid, methyl α-allyloxymethyl acrylate, ethyl α-allyloxymethyl acrylate, n-propyl α-allyloxymethyl acrylate, i-propyl α-allyloxymethyl acrylate, n-butyl α-allyloxymethyl acrylate, s-butyl α-allyloxymethyl acrylate, t-butyl α-allyloxymethyl acrylate, n-pentyl α-allyloxymethyl acrylate, s-pentyl α-allyloxymethyl acrylate, t-pentyl α-allyloxymethyl acrylate, neopentyl α-allyloxymethyl acrylate, n-hexyl α-allyloxymethyl acrylate, s-hexyl α-allyloxymethyl acrylate, n-heptyl α-allyloxymethyl acrylate, n-octyl α-allyloxymethyl acrylate, s-octyl α-allyloxymethyl acrylate, t-octyl α-allyloxymethyl acrylate, 2-ethylhexyl α-allyloxymethyl acrylate, nonyl α-allyloxymethyl acrylate, decyl α-allyloxymethyl acrylate, undecyl α-allyloxymethyl acrylate, lauryl α-allyloxymethyl acrylate, tridecyl α-allyloxymethyl acrylate, myristyl α-allyloxymethyl acrylate, pentadecyl α-allyloxymethyl acrylate, cetyl α-allyloxymethyl acrylate, heptadecyl α-allyloxymethyl acrylate, stearyl α-allyloxymethyl acrylate, nonadecyl α-allyloxymethyl acrylate, eicosyl α-allyloxymethyl acrylate, cerinyl α-allyloxymethyl acrylate, and melissyl α-allyloxymethyl acrylate, etc., which are α-(allyloxymethyl) acrylates containing a chain-like saturated hydrocarbon group.

[0029] α-(Allyloxymethyl)acrylates containing a hydroxy-substituted linear saturated hydrocarbon group such as hydroxyethyl α-allyloxymethylacrylate, hydroxypropyl α-allyloxymethylacrylate, and hydroxybutyl α-allyloxymethylacrylate; α-(Allyloxymethyl)acrylates containing a halogen-substituted linear saturated hydrocarbon group such as fluoroethyl α-allyloxymethylacrylate, difluoroethyl α-allyloxymethylacrylate, chloroethyl α-allyloxymethylacrylate, dichloroethyl α-allyloxymethylacrylate, bromoethyl α-allyloxymethylacrylate, and dibromoethyl α-allyloxymethylacrylate.

[0030] α-(Allyloxymethyl)acrylates containing an alicyclic hydrocarbon group such as cyclopentyl α-allyloxymethylacrylate, cyclopentylmethyl α-allyloxymethylacrylate, cyclohexylmethyl α-allyloxymethylacrylate, 4-methylcyclohexyl α-allyloxymethylacrylate, 4-t-butylcyclohexyl α-allyloxymethylacrylate, tricyclodecanyl α-allyloxymethylacrylate, isobornyl α-allyloxymethylacrylate, adamantyl α-allyloxymethylacrylate, dicyclopentanyl α-allyloxymethylacrylate, and dicyclopentenyl α-allyloxymethylacrylate; α-(Allyloxymethyl)acrylates containing an aromatic hydrocarbon group such as phenyl α-allyloxymethylacrylate, methylphenyl α-allyloxymethylacrylate, dimethylphenyl α-allyloxymethylacrylate, trimethylphenyl α-allyloxymethylacrylate, 4-t-butylphenyl α-allyloxymethylacrylate, diphenylmethyl α-allyloxymethylacrylate, diphenylethyl α-allyloxymethylacrylate, triphenylmethyl α-allyloxymethylacrylate, naphthyl α-allyloxymethylacrylate, and anthranyl α-allyloxymethylacrylate.

[0031] Chain-saturated hydrocarbon group-containing α-(allyloxymethyl) acrylates having a chain ether bond, such as methoxyethyl α-allyloxymethylacrylate, methoxyethoxyethyl α-allyloxymethylacrylate, methoxyethoxyethoxyethyl α-allyloxymethylacrylate, 3-methoxybutyl α-allyloxymethylacrylate, ethoxyethyl α-allyloxymethylacrylate, and ethoxyethoxyethyl α-allyloxymethylacrylate; alicyclic hydrocarbon group-containing α-(allyloxymethyl) acrylates having a chain ether bond, such as cyclopentyloxyethyl α-allyloxymethylacrylate, cyclohexyloxylethyl α-allyloxymethylacrylate, cyclopentyloxyethoxyethyl α-allyloxymethylacrylate, cyclohexyloxyethoxyethyl α-allyloxymethylacrylate, and dicyclopentenyl oxyethyl α-allyloxymethylacrylate; aromatic aliphatic hydrocarbon group-containing α-(allyloxymethyl) acrylates having a chain ether bond, such as phenoxyethyl α-allyloxymethylacrylate and phenoxyethoxyethyl α-allyloxymethylacrylate; cyclic ether group-based saturated hydrocarbon group-containing α-(allyloxymethyl) acrylates, such as glycidyl α-allyloxymethylacrylate, β-methylglycidyl α-allyloxymethylacrylate, β-ethylglycidyl α-allyloxymethylacrylate, 3,4-epoxycyclohexylmethyl α-allyloxymethylacrylate, 2-oxetanemethyl α-allyloxymethylacrylate, 3-methyl-3-oxetanemethyl α-allyloxymethylacrylate, 3-ethyl-3-oxetanemethyl α-allyloxymethylacrylate, tetrahydrofuranyl α-allyloxymethylacrylate, tetrahydrofurfuryl α-allyloxymethylacrylate, tetrahydropyranyl α-allyloxymethylacrylate, dioxazolanil α-allyloxymethylacrylate, and dioxanyl α-allyloxymethylacrylate.

[0032] Among these α-(allyloxymethyl) acrylates, from the viewpoints of viscosity and extensibility, methyl α-allyloxymethyl acrylate and tetrahydrofurfuryl α-allyloxymethyl acrylate are preferable.

[0033] The α-(allyloxymethyl) acrylate (C) can be produced, for example, by the method disclosed in International Publication No. 2010 / 114077. For example, as a method for producing α-(allyloxymethyl) acrylate, a method of performing the following reaction steps (a) to (c) is preferably mentioned. Also, it is preferable to use an amine-based catalyst in all of these reaction steps. That is, it is also one of the preferred embodiments of the present invention that these reaction steps include a step of reacting in the presence of an amine-based catalyst. (a) A step of reacting an acrylic acid ester with paraformaldehyde to obtain α-(hydroxymethyl) acrylate. (b) A step of obtaining 2,2’-[oxybis(methylene)] bisacrylate from α-(hydroxymethyl) acrylate. (c) A step of reacting 2,2’-[oxybis(methylene)] bisacrylate with allyl alcohol to produce α-(allyloxymethyl) acrylate and α-(hydroxymethyl) acrylate. Also, a production method using a transesterification reaction from a lower ester of α-allyloxymethyl acrylic acid such as methyl α-allyloxymethyl acrylate or ethyl α-allyloxymethyl acrylate is also preferable. The above (C) may be used alone or in combination of two or more.

[0034] The (meth)acrylate (D) having a urethane group is a urethane (meth)acrylate containing a polyol (a), a polyisocyanate (b), and an active hydrogen group-containing (meth)acrylate (c) as constituent raw materials.

[0035] Examples of the polyol (a) include linear aliphatic polyols (a1) having 1 to 20 carbon atoms, alicyclic polyols (a2) having 6 to 20 carbon atoms, aromatic polyols (a3) having 6 to 20 carbon atoms, and adducts thereof with alkylene oxides [ethylene oxide (hereinafter, “ethylene oxide” may be abbreviated as EO), 1,2- or 1,3-propylene oxide (hereinafter, “1,2-propylene oxide” may be abbreviated as PO), and 1,2-, 1,3-, 1,4- or 2,3-butylene oxide, etc.].

[0036] Examples of the linear aliphatic polyol (a1) include linear aliphatic diols having 1 to 20 carbon atoms (ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-dodecanediol, etc.), branched aliphatic diols (1,2-propylene glycol, 1,2-, 1,3- or 2,3-butanediol, 2-methyl-1,4-butanediol, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, etc.), and linear aliphatic tri- to octavalent alcohols (pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, dipentaerythritol, etc.).

[0037] Examples of the alicyclic polyol (a2) having 6 to 20 carbon atoms include 1,2-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1,4-cycloheptanediol, 1,4-bis(hydroxymethyl)cyclohexane, 2,2-bis(4-hydroxycyclohexyl)propane, and 1,3,5-cyclohexanetriol.

[0038] Examples of the aromatic polyol (a3) having 6 to 20 carbon atoms include resorcinol, hydroquinone, naphthalenediol, and bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.).

[0039] When using an alkylene oxide adduct of the above-mentioned linear aliphatic polyol (a1), alicyclic polyol (a2) or aromatic polyol (a3) as the polyol (a), the number of moles of alkylene oxide added is preferably 1 to 50 moles, more preferably 4 to 30 moles, from the viewpoint of the elongation of the cured product.

[0040] Among these polyols (a), preferably from the viewpoint of the elongation of the cured product, is an alkylene oxide adduct of the above-mentioned linear aliphatic polyol (a1), more preferably an ethylene oxide adduct, propylene oxide adduct or 1,4-butylene oxide adduct of the aliphatic polyol (a1), and particularly preferably polyethylene glycol, polypropylene glycol and polytetramethylene glycol (poly 1,4-butylene oxide). The polyol (a) may be used alone or in combination of two or more.

[0041] Examples of the polyisocyanate (b) include linear aliphatic polyisocyanates (b1) having 4 to 20 carbon atoms, alicyclic polyisocyanates (b2) having 6 to 22 carbon atoms, and aromatic polyisocyanates (b3) having 8 to 22 carbon atoms.

[0042] Examples of the linear aliphatic polyisocyanate (b1) having 4 to 20 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and lysine diisocyanate.

[0043] As the alicyclic polyisocyanate (b2) having 6 to 22 carbon atoms, cyclohexane-1,3-diylbis(methylene diisocyanate), isophorone diisocyanate (IPDI), 2,4- or 2,6-methylcyclohexane diisocyanate (hydrogenated TDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI; hereinafter sometimes referred to as MDIH), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, cyclohexane-1,3-diylbis(methylene diisocyanurate), bis(2-isocyanatoethyl)-4-cyclohexylene-1,2-dicarboxylate, 2,5- or 2,6-norbornane diisocyanate, dimer acid diisocyanate and the like can be mentioned.

[0044] As the aromatic polyisocyanate (b3) having 8 to 22 carbon atoms, 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'- or 2,4'-diphenylmethane diisocyanate (MDI), m- or p-isocyanatophenylsulfonyl isocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, m- or p-isocyanatophenylsulfonyl isocyanate, m- or p-xylylene diisocyanate (XDI), α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI) and the like can be mentioned.

[0045] Among these polyisocyanates (b), from the viewpoints of the elongation and light resistance of the cured product, alicyclic polyisocyanates (b2) having 6 to 22 carbon atoms and aromatic polyisocyanates (b3) having 8 to 22 carbon atoms are preferable, alicyclic polyisocyanates having 6 to 20 carbon atoms and aromatic polyisocyanates having 8 to 20 carbon atoms are more preferable, MDIH, cyclohexane-1,3-diylbis(methylene diisocyanurate), IPDI, XDI, TMXDI, MDI and TDI are particularly preferable, and MDIH, IPDI and MDI are most preferable. The polyisocyanate (b) may be used alone or in combination of two or more.

[0046] Examples of the active hydrogen group-containing (meth)acrylate (c) include hydroxyl group-containing (meth)acrylate (c1), amino group-containing (meth)acrylate (c2), carboxyl group-containing (meth)acrylate (c3), etc. Among these, from the viewpoint of the viscosity of the curable composition, a hydroxyl group-containing (meth)acrylate is preferred. Examples of the hydroxyl group-containing (meth)acrylate (c1) include hydroxyalkyl (meth)acrylate (c11) and polyalkylene glycol mono (meth)acrylate (c12), etc.

[0047] Preferred examples of the hydroxyalkyl (meth)acrylate (c11) include hydroxyalkyl (meth)acrylate having 4 to 20 carbon atoms, etc. Specifically, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, etc. can be mentioned.

[0048] Examples of the polyalkylene glycol mono (meth)acrylate (c12) include polyethylene glycol mono (meth)acrylate and polypropylene glycol mono (meth)acrylate, etc.

[0049] Examples of the amino group-containing (meth)acrylate (c2) include monoalkyl (having 1 to 4 carbon atoms) aminoalkyl (having 2 to 6 carbon atoms) (meth)acrylate {aminoethyl, aminopropyl, methylaminoethyl, ethylaminoethyl, butylaminoethyl or methylaminopropyl (meth)acrylate} and dialkyl (having 1 to 4 carbon atoms) aminoalkyl (having 2 to 6 carbon atoms) (meth)acrylate {dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate and dibutylaminoethyl (meth)acrylate, etc.}, etc.

[0050] Examples of the carboxyl group-containing (meth)acrylate (c3) include 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl phthalic acid, and 2-(meth)acryloyloxyethyl hexahydrophthalic acid.

[0051] Among the active hydrogen group-containing (meth)acrylates (c), from the viewpoints of the reactivity of the urethanization reaction and the elongation of the cured product, a hydroxyl group-containing (meth)acrylate (c1) is preferable, a hydroxyl group-containing monofunctional (meth)acrylate is more preferable, a hydroxyalkyl (meth)acrylate (c11) is particularly preferable, and 2-hydroxyethyl (meth)acrylate is most preferable. The active hydrogen group-containing (meth)acrylate (c) may be used alone or in combination of two or more. The (meth)acrylate (D) having the urethane group may be used alone or in combination of two or more.

[0052] Regarding the polyol (a), polyisocyanate (b), and active hydrogen group-containing (meth)acrylate (c) which are the constituent raw materials of the (meth)acrylate (D) having the urethane group, the molar ratio of the isocyanate group of the polyisocyanate (b) to the active hydrogen groups of the polyol (a) and the active hydrogen group-containing (meth)acrylate (c) [(isocyanate group of (b) / total of active hydrogen groups of (a) and (c))] is not particularly limited, but from the viewpoint of storage stability, it is preferably 1 / 0.5 to 1 / 10, more preferably 1 / 0.7 to 1 / 5, and particularly preferably 1 / 1 to 1 / 2.

[0053] The number average molecular weight of the (meth)acrylate (D) having the urethane group (hereinafter, may be abbreviated as Mn) is preferably 500 to 50,000, more preferably 700 to 20,000, and particularly preferably 1,000 to 10,000.

[0054] Mn in the present invention can be measured by gel permeation chromatography (GPC) under the following conditions. Apparatus: "Waters Alliance 2695" [manufactured by Waters] Column: "Guardcolumn Super H-L" (1 piece), "TSKgel SuperH2000, TSKgel SuperH3000, TSKgel SuperH4000 (all manufactured by Tosoh Corporation), each connected in series with 1 piece" Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection volume: 10 μl Flow rate: 0.6 ml / min Measurement temperature: 40 °C Detector: Refractive index detector Reference substance: Standard polyethylene glycol

[0055] The (meth)acrylate (D) having a urethane group in the present invention can be produced by reacting a polyol (a), a polyisocyanate (b) and an active hydrogen group-containing (meth)acrylate (c) by a known method. Among them, it is preferable to produce a urethane prepolymer having two or more isocyanate groups by a polyaddition reaction of (a) and (b), and then to carry out an addition reaction of (c). In the above polyaddition reaction and addition reaction, a urethanization catalyst may be used. Examples of the urethanization catalyst include metal compounds (organic bismuth compounds, organic tin compounds, organic titanium compounds, etc.) and quaternary ammonium salts.

[0056] The active energy ray-curable composition of the present invention may contain an ethylenically unsaturated monomer other than the above-mentioned (meth)acrylate (A) having an alicyclic skeleton, N-substituted (meth)acrylamide (B), α-(allyloxymethyl)acrylate (C) and (meth)acrylate (D) having a urethane group. Examples of other ethylenically unsaturated monomers include monofunctional ethylenically unsaturated monomers, difunctional ethylenically unsaturated monomers, and ethylenically unsaturated monomers having three or more functional groups.

[0057] [Monofunctional ethylenically unsaturated monomer] Examples of the monofunctional ethylenically unsaturated monomers include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, isoamyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, 5-ethyl-1,3-dioxan-5-ylmethyl acrylate, 2-ethylhexyl diglycol (meth)acrylate, 2-chloroethyl (meth)acrylate, 4-bromobutyl (meth)acrylate, 2-ethylhexyl carbitol (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 1H,1H,2H,2H-perfluorodecyl (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 2,4,5-trimethylphenyl (meth)acrylate, 4-chlorophenyl (meth)acrylate, phenoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, glycidyloxybutyl (meth)acrylate, glycidyloxyethyl (meth)acrylate, glycidyloxypropyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, trimethylsilylpropyl (meth)acrylate, trifluoroethyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, N-vinylpyrrolidone, N-vinylcaprolactone, and 3-vinyl-5-methyl-2-oxazolidinone.

[0058] Examples of the difunctional ethylenically unsaturated monomers include difunctional (meth)acrylate monomers.

[0059] [Bifunctional (meth)acrylate monomer] Examples of the bifunctional (meth)acrylate monomer include 1,6 - hexanediol di(meth)acrylate, 1,10 - decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2,4 - dimethyl - 1,5 - pentanediol di(meth)acrylate, 2 - ethyl - 2 - butyl - butanediol di(meth)acrylate, 1,4 - butanediol di(meth)acrylate, 2 - ethyl - 2 - butyl - propanediol di(meth)acrylate, 1,9 - nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol #200 di(meth)acrylate (#200 means the number - average molecular weight of 200. The same applies hereinafter), polyethylene glycol #300 di(meth)acrylate, polyethylene glycol #400 di(meth)acrylate, polyethylene glycol #600 di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol #400 di(meth)acrylate, and polypropylene glycol #700 di(meth)acrylate, etc.

[0060] Examples of the ethylenically unsaturated monomer having three or more functional groups include trifunctional (meth)acrylate monomers and (meth)acrylate monomers having four or more functional groups, etc.

[0061] [Trifunctional (meth)acrylate monomer] Examples of the monomer include trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, alkylene oxide-modified tri(meth)acrylate of trimethylolpropane having 3 to 4 carbon atoms, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, trimethylolpropane tri((meth)acryloyloxypropyl) ether, sorbitol tri(meth)acrylate, tri(meth)acrylate of an adduct of 1 to 30 moles of alkylene oxide having 3 to 4 carbon atoms with pentaerythritol, ethoxylated glycerin tri(meth)acrylate, and the like.

[0062] [(Meth)acrylate monomer having 4 or more functional groups] Examples of the (meth)acrylate monomer having 4 or more functional groups include pentaerythritol tetra(meth)acrylate, sorbitol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate propionate, tetra(meth)acrylate of an adduct of 1 to 11 moles of alkylene oxide having 3 to 4 carbon atoms with pentaerythritol, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate, and the like.

[0063] Examples of the photopolymerization initiator (E) include benzoin compounds (E-1), alkylphenone compounds (E-2), anthraquinone compounds (E-3), thioxanthone compounds (E-4), benzophenone compounds (E-5), phosphine oxides (E-6), and oxime ester compounds (E-7), and the like.

[0064] Examples of the benzoin compound (E-1) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether, and the like.

[0065] Examples of the alkylphenone compound (E-2) include acetophenone, α-hydroxyalkylphenone acetophenone, (2-hydroxy-2-methyl-phenylpropan-1-one and 1-hydroxycyclohexyl phenyl ketone, etc.), α-aminoalkylphenone [2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, etc.], acetophenone dimethyl ketal, benzyldimethyl ketal, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, and diethoxyacetophenone.

[0066] Examples of the anthraquinone compound (E-3) include 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-chloroanthraquinone, and 2-amylanthraquinone, etc.

[0067] Examples of the thioxanthone compound (E-4) include 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 2-chlorothioxanthone, etc.

[0068] Examples of the benzophenone compound (E-5) include benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 4,4'-bis(methylamino)benzophenone, etc.

[0069] Examples of the phosphine oxide (E-6) include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc.

[0070] Examples of the oxime ester compound (E-7) include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime) and ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime).

[0071] Among the photoinitiators (E), from the viewpoint of curability, alkylphenone compounds (E-2) and phosphine oxides (E-6) are preferred, alkylphenone compounds (E-2) are more preferred, and α-hydroxyalkylphenones, acetophenones and α-aminoalkylphenones are particularly preferred. The photoinitiator (E) may be used alone or in combination of two or more.

[0072] The active energy ray-curable composition of the present invention may contain other additives in addition to the above (A), (B), (C), (D), (E) and other ethylenically unsaturated monomers. Examples of other additives include slip agents (F) and polymerization inhibitors (G).

[0073] Examples of the slip agent (F) include silicone slip agents (F1) and fluorine slip agents (F2). Further, (F) may contain a radical polymerization reactive group.

[0074] Examples of the silicone slip agent (F1) include alkylene oxide (hereinafter abbreviated as AO)-modified polydialkylsiloxane. Examples of the AO-modified polydialkylsiloxane include polydialkylsiloxane (F11) whose terminal is modified with AO, and polydialkylsiloxane (F12) whose side chain of polysiloxane is modified with AO. Note that the polydialkylsiloxane (F11) and the polydialkylsiloxane (F12) may be further modified with (meth)acryloyl.

[0075] Examples of the above-mentioned polydialkylsiloxane (F11) include polydimethylsiloxane with a terminal modified by EO, polydimethylsiloxane with a terminal modified by EO and PO, polydiethylsiloxane with a terminal modified by EO, and (meth)acrylates thereof.

[0076] Examples of the above-mentioned polydialkylsiloxane (F12) include polydimethylsiloxane with a side chain modified by PO, polydimethylsiloxane with a side chain modified by EO and butylene oxide, polydimethylsiloxane with a side chain modified by EO and PO, and (meth)acrylates thereof.

[0077] Among these silicone slip agents (F1), from the viewpoint of coatability, the preferred one is the above-mentioned polydialkylsiloxane (F12), and more preferably polydimethylsiloxane with a side chain modified by EO and PO.

[0078] Examples of the above-mentioned fluorine slip agent (F2) include perfluoroalkyl ethylene oxide adducts. Further, examples of the perfluoroalkyl ethylene oxide adduct include perfluoro compounds (F21) with a terminal modified by alkylene oxide and perfluoro compounds (F22) with a side chain modified by alkylene oxide. Note that the perfluoro compound (F21) and the perfluoro compound (F22) may be further (meth)acryloyl-modified.

[0079] The Mn of the above-mentioned slip agent (F) is preferably 300 to 50,000. The slip agent (F) may be used alone or in combination of two or more.

[0080] Examples of the polymerization inhibitor (G) include phenolic compounds [hydroquinone, 4-methoxyphenol, 2,6-di-t-butyl-p-cresol, 2,2-methylenebis-(4-methyl-6-t-butylphenol), 1,1,3-tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane, etc.], sulfur compounds (dilauryl thiodipropionate, etc.), phosphorus compounds (triphenyl phosphite, etc.), and amine compounds (phenothiazine, etc.). The polymerization inhibitor (G) may be used alone or in combination of two or more.

[0081] The weight ratio of the (meth)acrylate (A) having an alicyclic skeleton in the present invention is 20% by weight to 70% by weight, preferably 30% to 70% by weight, and more preferably 40% to 70% by weight based on the total weight of the (meth)acrylate (A) having an alicyclic skeleton, the N-substituted (meth)acrylamide (B), α-(allyloxymethyl)acrylate (C), and the (meth)acrylate (D) having a urethane group. When the weight ratio of (A) is less than 20% by weight, the elastic modulus is insufficient, and when it exceeds 70% by weight, the elongation is insufficient.

[0082] The weight ratio of the N-substituted (meth)acrylamide (B) in the present invention is 5% by weight to 40% by weight, preferably 5% to 30% by weight, and more preferably 5% to 25% by weight based on the total weight of the (meth)acrylate (A) having an alicyclic skeleton, the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl)acrylate (C), and the (meth)acrylate (D) having a urethane group. When the weight ratio of (B) is less than 5% by weight, the elastic modulus is insufficient, and when it exceeds 40% by weight, the water absorption rate is high.

[0083] The weight ratio of α-(allyloxymethyl) acrylate (C) is 5% by weight to 30% by weight, preferably 5 to 25% by weight, more preferably 5 to 20% by weight, based on the total weight of the (meth)acrylate (A) having the alicyclic skeleton, the N-substituted (meth)acrylamide (B), α-(allyloxymethyl) acrylate (C), and the (meth)acrylate (D) having a urethane group. When the weight ratio of (C) is less than 5% by weight, the viscosity is too high and the handleability is insufficient. When it exceeds 30% by weight, the water absorption rate is high.

[0084] The weight ratio of the (meth)acrylate (D) having a urethane group in the present invention is 10 to 40% by weight, preferably 12 to 38% by weight, more preferably 13 to 35% by weight, based on the total weight of the (meth)acrylate (A) having the alicyclic skeleton, the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl) acrylate (C), and the (meth)acrylate (D) having a urethane group. When the weight ratio of (D) is less than 10% by weight, the elongation is insufficient. When it exceeds 40% by weight, the viscosity is too high and the handleability is insufficient.

[0085] The weight ratio of the photopolymerization initiator (E) in the present invention is 2% by weight to 10% by weight, preferably 2.5 to 8% by weight, more preferably 3 to 6% by weight, based on the total weight of the (meth)acrylate (A) having the alicyclic skeleton, the N-substituted (meth)acrylamide (B), the radically polymerizable monomer (C), and the (meth)acrylate (D) having a urethane group. When the weight ratio of (E) is less than 2% by weight, the curability may be insufficient. When it exceeds 10% by weight, at least one of the elongation, viscosity, and elastic modulus is insufficient.

[0086] The weight ratio of other ethylenically unsaturated monomers other than the (meth)acrylate (A) having the alicyclic skeleton, N-substituted (meth)acrylamide (B), α-(allyloxymethyl)acrylate (C), and (meth)acrylate (D) having a urethane group is preferably 20% by weight or less, more preferably 10% by weight or less, based on the total weight of the (meth)acrylate (A) having the alicyclic skeleton, the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl)acrylate (C), and the (meth)acrylate (D) having a urethane group.

[0087] The weight ratio of the slip agent (F) of the present invention is preferably 0.01 to 5% by weight, more preferably 0.1 to 3% by weight, based on the total weight of the (meth)acrylate (A) having the alicyclic skeleton, the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl)acrylate (C), and the (meth)acrylate (D) having a urethane group, from the viewpoint of the coatability of the active energy ray curable composition. The weight ratio of the polymerization inhibitor (G) of the present invention is preferably 0.01 to 5% by weight, more preferably 0.05 to 3% by weight, based on the total weight of the (meth)acrylate (A) having the alicyclic skeleton, the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl)acrylate (C), and the (meth)acrylate (D) having a urethane group, from the viewpoints of the storage stability and polymerization rate of the active energy ray curable composition.

[0088] The method for producing the active energy ray curable composition of the present invention is not particularly limited. For example, a monofunctional (meth)acrylate (A) having the alicyclic skeleton, the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl)acrylate (C), the (meth)acrylate (D) having a urethane group, and a photopolymerization initiator (E), and, if necessary, other ethylenically unsaturated monomers and other additives are uniformly mixed by using a known mechanical mixing method (a method using a mechanical stirrer, a magnetic stirrer, etc.) in a temperature range of 20 to 80°C, whereby it can be produced.

[0089] The cured product of the present invention is obtained by curing the above-described active energy ray-curable composition. That is, the above-described active energy ray-curable composition is cured by active energy rays to form a cured product. Examples of the active energy rays include ultraviolet rays and electron beams. When irradiating the above-described ultraviolet rays, a known ultraviolet irradiation device equipped with a high-pressure mercury lamp, a metal halide lamp, etc. can be used. The irradiation dose of ultraviolet rays is preferably 10 to 10,000 mJ / cm 2 from the viewpoints of curability and suppression of yellowing deterioration, and more preferably 100 to 5,000 mJ / cm 2 is. When irradiating the above-described electron beam, a known electron beam irradiation device can be used. The irradiation dose of the electron beam is preferably 1 to 10 Mrad from the viewpoints of curability and suppression of deterioration of the cured product.

[0090] The cured product of the active energy ray-curable composition of the present invention has high elongation and a high elastic modulus, and thus is useful as a material for flexible displays.

Examples

[0091] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In addition, GPC in the examples was measured under the following conditions. Apparatus: "Waters Alliance 2695" [manufactured by Waters Corporation] Column: "Guardcolumn Super H-L" (1 piece), "TSKgel" SuperH2000, TSKgel SuperH3000, TSKgel SuperH4000 (all manufactured by Tosoh Corporation), each connected in one piece Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection volume: 10 μl Flow rate: 0.6 ml / min Measurement temperature: 40 °C Detector: Refractive index detector Reference substance: Standard polyethylene glycol

[0092] Production Example 1 [Synthesis of Tetrahydrofurfuryl α-allyloxymethylacrylate (THF-AMA) (C-2)] Into a reactor equipped with a stirrer, a cooling pipe, a thermometer, and a gas injection pipe, 198.4 parts by weight of tetrahydrofurfuryl alcohol (THFOH), 100.1 parts by weight of AOMA (α-allyloxymethyl methyl acrylate, manufactured by Nippon Shokubai Co., Ltd.), 10.9 parts by weight of titanium tetrabutoxide, and 0.10 part by weight of 4H-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) were charged. While stirring, the temperature was raised to 100 °C while passing an oxygen / nitrogen mixed gas (oxygen concentration 8%), and the reaction was carried out for 14 hours. After the reaction was completed, analysis by gas chromatography showed that tetrahydrofurfuryl α-allyloxymethyl acrylate (THF-AMA):AOMA:tetrahydrofurfuryl alcohol was 24:11:51 in terms of area ratio. Also, n-butyl α-allyloxymethyl acrylate (nBu-AMA), an impurity derived from the catalyst, was contained in an amount of 15 area% with respect to THF-AMA. This reaction solution was diluted with n-hexane, water was added, and the titanium compound was precipitated and removed by filtration. The filtrate was subjected to oil-water separation, water was added to the obtained organic layer, stirred well, allowed to stand, and subjected to oil-water separation, and the residual tetrahydrofurfuryl alcohol was removed to the aqueous layer side. 0.15 part by weight of 4H-TEMPO was added to the obtained organic layer, and it was charged into a reactor equipped with a stirrer, a temperature sensor, a gas introduction pipe, a T-shaped pipe, a cooling pipe, and a distillate receiver. While stirring, while passing an oxygen / nitrogen mixed gas (oxygen concentration 8%), the pressure in the reactor was gradually reduced until it reached 400 Pa. After reaching 400 Pa, the temperature was gradually raised, and the residual AOMA was removed until the internal temperature reached 80 °C. Then, it was cooled and depressurized. The obtained liquid was diluted with n-hexane, water was added, stirred well, allowed to stand, and subjected to oil-water separation. This operation was repeated 3 times to remove 4H-TEMPO. The obtained organic layer was charged into a reactor equipped with a stirrer, a temperature sensor, a gas introduction pipe, a T-shaped pipe, a cooling pipe, and a distillate receiver. While stirring, while passing an oxygen / nitrogen mixed gas (oxygen concentration 8%), while heating so that the internal temperature became 25 to 30 °C, the pressure was slowly reduced until it reached 800 Pa to remove n-hexane. After reaching 800 Pa, the pressure was maintained for 20 minutes and then depressurized to obtain 70.0 parts by weight of the target compound, THF-AMA (C-2).To the obtained THF-AMA(C-2), 0.021 parts by weight of p-methoxyphenol was added and prepared so that the concentration of p-methoxyphenol became 300 ppm.

[0093] Production Example 2 [Synthesis of (meth)acrylate (D-1) having a urethane group] Into a reaction vessel, 412 parts by weight of polytetramethylene glycol [trade name "PTMG1000", manufactured by Mitsubishi Chemical Corporation, number average molecular weight: 1000], 182 parts by weight of isophorone diisocyanate (IPDI), and 0.2 parts by weight of a urethanization catalyst [bismuth tris(2-ethylhexanoate) (50 wt% solution of 2-ethylhexanoic acid); the same applies hereinafter] were charged, and reacted at 110°C for 3 hours. Then, 104 parts by weight of 2-hydroxyethyl acrylate was added and reacted at 80°C for 6 hours to obtain a (meth)acrylate (D-1) having a urethane group. The number average molecular weight of (D-1) was 1700.

[0094] Production Example 3 [Synthesis of (meth)acrylate (D-2) having a urethane group] Into a reaction vessel, 191 parts by weight of polytetramethylene glycol [trade name "PTMG850", manufactured by Mitsubishi Chemical Corporation, number average molecular weight: 850], 101 parts by weight of IPDI, and 0.3 parts by weight of a urethanization catalyst were charged, and reacted at 110°C for 3 hours. Then, 58 parts by weight of 2-hydroxyethyl acrylate was added and reacted at 80°C for 6 hours to obtain a (meth)acrylate (D-2) having a urethane group. The number average molecular weight of (D-2) was 1600.

[0095] Production Example 4 [Synthesis of (meth)acrylate (D-3) having a urethane group] Into a reaction vessel, 337 parts by weight of polytetramethylene glycol [trade name "PTMG650", manufactured by Mitsubishi Chemical Corporation, number average molecular weight: 650], 230 parts of IPDI, and 0.1 parts by weight of a urethanization catalyst were charged, and reacted at 110°C for 4 hours. Then, 132 parts by weight of 2-hydroxyethyl acrylate was added and reacted at 80°C for 8 hours to obtain a (meth)acrylate (D-3) having a urethane group. The number average molecular weight of (D-3) was 1350.

[0096] Production Example 5 [Synthesis of (Meth)acrylate (D-4) Having Urethane Group] Into a reaction vessel, 259 parts by weight of polytetramethylene glycol [trade name "PTMG2000", manufactured by Mitsubishi Chemical Corporation, number average molecular weight: 2000], 57 parts by weight of IPDI, and 0.1 part by weight of a urethanization catalyst were charged, and the mixture was reacted at 110 °C for 4 hours. Then, 33 parts by weight of 2-hydroxyethyl acrylate was added, and the mixture was reacted at 80 °C for 8 hours to obtain a (meth)acrylate (D-4) having a urethane group. The number average molecular weight of (D-4) was 2700.

[0097] Production Example 6 [Synthesis of (Meth)acrylate (D-5) Having Urethane Group] Into a reaction vessel, 258 parts by weight of polypropylene glycol [trade name "Sunnex PP-2000", manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight: 2000], 58 parts by weight of IPDI, and 0.1 part by weight of a urethanization catalyst were charged, and the mixture was reacted at 110 °C for 4 hours. Then, 33 parts by weight of 2-hydroxyethyl acrylate was added, and the mixture was reacted at 80 °C for 8 hours to obtain a (meth)acrylate (D-5) having a urethane group. The number average molecular weight of (D-5) was 2600.

[0098] Production Example 7 [Synthesis of (Meth)acrylate (D-6) Having Urethane Group] Into a reaction vessel, 258 parts by weight of polypropylene glycol [trade name "Sunnex PP-2000", manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight: 2000], 65 parts by weight of MDI, and 0.1 part by weight of a urethanization catalyst were charged, and the mixture was reacted at 110 °C for 4 hours. Then, 33 parts by weight of 2-hydroxyethyl acrylate was added, and the mixture was reacted at 80 °C for 8 hours to obtain a (meth)acrylate (D-6) having a urethane group. The number average molecular weight of (D-6) was 2700.

[0099] Production Example 8 [Synthesis of (Meth)acrylate (D-7) Having Urethane Group] 240 parts by weight of polypropylene glycol [trade name "Sun Nitsukusu PP-1000", manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight: 1000], 80 parts by weight of IPDI, and 0.1 part by weight of a urethanization catalyst were charged into a reaction vessel, and the mixture was reacted at 110 °C for 4 hours. Then, 30 parts by weight of 2-hydroxyethyl acrylate was added, and the mixture was reacted at 80 °C for 8 hours to obtain a (meth)acrylate (D-7) having a urethane group. The number average molecular weight of (D-7) was 2900.

[0100] Examples 1 to 11 and Comparative Examples 1 to 11 The composition shown in Table 1 (parts by weight) was uniformly mixed at 60 °C to obtain the active energy ray curable compositions of Examples and Comparative Examples.

[0101] [Table 1]

[0102] The contents indicated by the symbols in Table 1 are as follows. (A-1): Isobornyl acrylate [trade name "Light Acrylate IBXA", manufactured by Kyoeisha Chemical Co., Ltd.] (A-2): Dicyclopentanyl acrylate [trade name "FA-513AS", manufactured by Hitachi Chemical Co., Ltd.] (A-3): 4-t-Butylcyclohexyl acrylate [trade name "TBCHA", manufactured by KJ Chemicals Co., Ltd.] (A-4): 3,3,5-Trimethylcyclohexyl acrylate [trade name "SR-420", manufactured by Arkema Co., Ltd.] (B-1): Dimethylacrylamide [trade name "DMAA", manufactured by KJ Chemicals Co., Ltd.] (B-2): Diethylacrylamide [trade name "DEAA", manufactured by KJ Chemicals Co., Ltd.] (B-3): Acryloylmorpholine [trade name "ACMO", manufactured by KJ Chemicals Co., Ltd.] (C-1): Methyl α-allyloxymethyl acrylate [trade name "AOMA", manufactured by Nippon Shokubai Co., Ltd.] (R 1 is a methyl group, R 2 , R 3 , R4 , R 5 and R 6 is a hydrogen atom) (E-1): 1-Hydroxycyclohexyl phenyl ketone [Trade name: Omnirad 184, manufactured by IGM Resins B.V.] (E-2): 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one [Trade name: Omnirad 907, manufactured by IGM Resins B.V.] (E-3): 2,4,6-Trimethylbenzoyl-diphenylphosphine oxide [Trade name: Omnirad TPO, manufactured by IGM Resins B.V.] (F-1): Alkylene oxide-modified polydimethylsiloxane [Trade name: BYK-333, manufactured by BYK-Chemie Japan Co., Ltd.] (F-2): Perfluoroalkyl ethylene oxide adduct [Trade name: Megafac F-444, manufactured by DIC Corporation] (G-1): 4-Methoxyphenol [Trade name: MQ-F, manufactured by Kawaguchi Chemical Industry Co., Ltd.]

[0103] Regarding the active energy ray-curable resin compositions of Examples 1 to 11 and the comparative active energy ray-curable resin compositions of Comparative Examples 1 to 11, the viscosity, as well as the elongation and tensile elastic modulus at room temperature (25°C) of each cured product obtained by curing the active energy ray-curable composition, were evaluated by the following method. The results are shown in Table 1.

[0104] <Viscosity Evaluation> The viscosity of the active energy ray-curable composition was measured using a viscosity measuring device ["Visc Elite B type" manufactured by FUNGILAB] at 25°C. A low viscosity with a viscosity of 150 mPa·s or less is suitable for handling.

[0105] <Preparation of Test Specimens> On a glass plate [product name: GLASS PLATE, manufactured by AS ONE Corporation, 200 mm in length × 200 mm in width × 5 mm in thickness], a PET film [product name: Lumirror S, manufactured by Toray Industries, Inc.] was pasted, and an active energy ray curable composition was applied using an applicator so that the film thickness after curing would be 100 μm. Under a nitrogen atmosphere, ultraviolet rays were irradiated at 300 mJ / cm 2 using an ultraviolet irradiation device [model number "VPS / I600", manufactured by Fusion UV Systems, Inc.], to obtain a PET film coated with a cured product of the active energy ray curable composition. The PET film coated with the above cured product was punched into a dumbbell shape No. 3 in accordance with JIS K 6251:2017, and then the PET film was peeled off to obtain a test piece for measurement.

[0106] <Curing evaluation> The surface of the obtained test piece for measurement was touched by finger to evaluate the presence or absence of tack. [Evaluation criteria] ○: No tack ×: Tack present

[0107] <Water absorption evaluation> The obtained test piece for measurement was completely immersed in a 25°C aqueous solution for 24 hours, and the water absorption rate of the cured product was calculated from the weight change before and after the test. Water absorption rate (%) = (weight after immersion - weight before immersion) / (weight before immersion) × 100

[0108] <Tensile test> After the obtained test piece for measurement was allowed to stand at 25°C and 50% RH for 5 hours, a tensile test was carried out in accordance with JIS K 6251:2017 using an autograph [model number "AG-IS", manufactured by Shimadzu Corporation]. At this time, the tensile test was carried out with a distance between chucks of 60 mm, a distance between gauge marks of 20 mm, and a tensile speed of 10 mm / min, and the elongation rate and tensile elastic modulus were calculated by the following calculation formulas.

[0109] <Elongation rate: Evaluation of elongation of cured product> Elongation rate (%) = (distance between gauge marks at break - distance between gauge marks) / (distance between gauge marks) × 100 <Tensile Elastic Modulus: Evaluation of the Elastic Modulus of the Cured Product> Tensile elastic modulus (MPa) = [Difference in force (N) between two points: Using the points of 1 N and 3 N] / [Difference in displacement (mm) between two points: Using the points of 1 N and 3 N] × (Gauge length: 20 mm) / (Cross-sectional area at the center of the dumbbell in mm 2 )

[0110] It is preferable that the water absorption rate of the cured product is 1.5% or less, the elongation rate is 50% or more, and the tensile elastic modulus is 1700 or more. From the results in Table 1, it can be seen that the active energy ray-curable composition of the present invention has a low viscosity, and the cured product of the active energy ray-curable composition has a low water absorption rate and is excellent in both its elongation and elastic modulus. On the other hand, the cured products of the active energy ray-curable compositions of Comparative Examples 1 to 11 are not sufficient in at least one of the water absorption rate of the cured product, the elongation of the cured product, and the elastic modulus of the cured product.

Industrial Applicability

[0111] Since the cured product of the active energy ray-curable composition of the present invention is excellent in both elongation and elastic modulus, it is useful as a material for flexible displays.

Claims

1. An active energy ray-curable composition containing an alicyclic skeleton-containing (meth)acrylate (A), an N-substituted (meth)acrylamide (B), an α-(allyloxymethyl)acrylate (C) represented by the following general formula (1), a (meth)acrylate (D) having a urethane group, and a photopolymerization initiator (E), wherein the (meth)acrylate (D) having a urethane group is a urethane (meth)acrylate containing a polyol (a), a polyisocyanate (b), and an active hydrogen group-containing (meth)acrylate (c) as constituent raw materials, Based on the total weight of the alicyclic skeleton-containing (meth)acrylate (A), the N-substituted (meth)acrylamide (B), the α-(allyloxymethyl)acrylate (C) represented by the general formula (1), and the (meth)acrylate (D) having a urethane group, the alicyclic skeleton-containing (meth)acrylate (A) is 20% to 70% by weight, the N-substituted (meth)acrylamide (B) is 5% to 40% by weight, the α-(allyloxymethyl)acrylate (C) represented by the general formula (1) is 5% to 30% by weight, the (meth)acrylate (D) having a urethane group is 10% to 40% by weight, and the photopolymerization initiator (E) is 2% to 10% by weight. An active energy ray-curable composition. 【Chemical 1】 [In formula (1), R １ represents a hydrogen atom or an organic group having 1 to 30 carbon atoms. R ２ , R ３ , R ４ , R ５ and R ６ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.]

2. The active energy ray-curable composition according to claim 1, wherein the (meth)acrylate (D) having a urethane group is a urethane (meth)acrylate having a (meth)acryloyl group, the polyol (a) is at least one polyol selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and the polyisocyanate (b) is at least one polyisocyanate selected from the group consisting of dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

3. The active energy ray-curable composition according to claim 1 or 2, wherein the alicyclic skeleton-containing (meth)acrylate (A) is at least one monomer selected from the group consisting of isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, and trimethylcyclohexyl (meth)acrylate.

4. The active energy ray-curable composition according to any one of claims 1 to 3, wherein the N-substituted (meth)acrylamide (B) is at least one monomer selected from the group consisting of (meth)acryloylmorpholine, diethyl (meth)acrylamide, and dimethyl (meth)acrylamide.

5. A cured product obtained by curing the active energy ray-curable composition according to any one of claims 1 to 4.

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