Photocurable resin sheet

Abstract

The purpose of the present invention is to provide a photocurable resin sheet having excellent scratch resistance at high temperatures. The present invention is a photocurable resin sheet containing (A) a polymer compound having an epoxy group and (B) a low-molecular compound having a photopolymerization initiating group, the epoxy functional group equivalent (X) of the polymer compound (A) being 100 g / eq < X < 400 g / eq.

Description

Technical Field

[0001] The present invention relates to a photocurable resin sheet. Background Art

[0002] Photocurable resin compositions have been widely used in optical applications such as displays, adhesives for optical semiconductors, lenses, protective films, etc. Most of these resin compositions are liquid at room temperature (25° C.) and are used by means of a dispenser.

[0003] On the other hand, Patent Document 1 discloses a photocurable resin sheet, wherein the photocurable resin sheet comprises (A) a polymer compound and (B) a low molecular weight compound, and an epoxy group, an oxetanyl group and a photopolymerization initiating group are each independently present in the polymer compound (A) or the low molecular weight compound (B).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-091682 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In recent years, from the viewpoint of reliability, optical materials are required to have durability at high temperatures. However, the conventional optical materials described in Patent Document 1, etc., have been newly found through research by the inventors of the present invention that under high temperature conditions, the strength of the components is low, and the ability to withstand external impacts and damage is weak, which may impair the optical function.

[0009] An object of the present invention is to solve the new problems found by the present inventors and to provide a photocurable resin sheet having excellent scratch resistance at high temperatures.

[0010] Means used to solve problems

[0011] The present invention (1) relates to a photocurable resin sheet, wherein the photocurable resin sheet comprises: (A) a polymer compound having an epoxy group and (B) a low molecular compound having a photopolymerization initiating group, wherein the epoxy functional group equivalent X of the polymer compound (A) is 100 g / eq<X<400 g / eq.

[0012] The present invention (2) relates to the photocurable resin sheet according to the present invention (1), wherein the weight average molecular weight of the polymer compound (A) is 1,000 to 1,000,000.

[0013] The present invention (3) relates to the photocurable resin sheet according to the present invention (1) or (2), wherein the molecular weight of the low molecular weight compound (B) is less than 1,000.

[0014] The present invention (4) relates to the photocurable resin sheet according to any one of the present inventions (1) to (3), wherein the storage modulus G' of the polymer compound (A) at 30 °C is 1,000,000 Pa or more.

[0015] The present invention (5) relates to the photocurable resin sheet according to any one of the present inventions (1) to (4), wherein the polymer compound (A) is a resin obtained by polymerizing a vinyl monomer.

[0016] The present invention (6) relates to the photocurable resin sheet according to any one of the present inventions (1) to (5), wherein the polymer compound (A) is a poly(meth)acrylic resin.

[0017] The present invention (7) relates to the photocurable resin sheet according to any one of the present inventions (1) to (6), wherein the transmittance of the cured product obtained by irradiating ultraviolet rays of 500 mJ / cm 2 and then performing a heat treatment at 150 °C for 15 minutes at a wavelength of 400 nm at 25 °C is 70% or more, and the refractive index with respect to light having a wavelength of 589 nm is 1.40 or more.

[0018] The present invention (8) relates to the photocurable resin sheet according to any one of the present inventions (1) to (7), wherein the glass transition temperature of the cured product obtained by irradiating ultraviolet rays of 500 mJ / cm 2 and then performing a heat treatment at 150 °C for 15 minutes is 100 °C or more, or the glass transition temperature cannot be measured.

[0019] The present invention (9) relates to the photocurable resin sheet according to any one of the present inventions (1) to (8), wherein the cured product obtained by irradiating ultraviolet rays of 500 mJ / cm 2 and then performing a heat treatment at 150 °C for 15 minutes satisfies the following formula for the tensile elastic modulus E' (at 25 °C) at 25 °C and the tensile elastic modulus E' (at 150 °C) at 150 °C: 1 < E' (at 25 °C) / E' (at 150 °C) < 10

[0020] The present invention (10) relates to the photocurable resin sheet according to any one of the present inventions (1) to (9), wherein the tensile elastic modulus E' (at 100 °C) of the cured product obtained by irradiating ultraviolet rays of 500 mJ / cm 2 and then performing a heat treatment at 150 °C for 15 minutes at 100 °C is 200,000,000 Pa or more.

[0021] The present invention (11) relates to the photocurable resin sheet according to any one of the present inventions (1) to (10), wherein the photocurable resin sheet is used for optical applications.

[0022] The present invention (12) also relates to an optical material obtained by curing the photocurable resin sheet according to any one of the present inventions (1) to (11).

[0023] Effects of the Invention

[0024] The photocurable resin sheet of the present invention comprises (A) a polymer compound having an epoxy group and (B) a low molecular compound having a photopolymerization initiating group. The epoxy functional group equivalent X of the polymer compound (A) is 100 g / eq<X<400 g / eq, and thus has excellent scratch resistance at high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view schematically showing an example of a photocurable resin sheet.

[0026] Figure 2 (A) Figure 2 (B) is a cross-sectional view schematically showing an example of a photocurable resin sheet laminate.

[0027] Figure 3 (A) Figure 3 (B) is a cross-sectional view schematically showing an example of a photocurable resin sheet laminate.

[0028] Figure 4 It is a cross-sectional view schematically showing an example of a wound body. DETAILED DESCRIPTION

[0029] The photocurable resin sheet of the present invention comprises (A) a polymer compound having an epoxy group and (B) a low molecular compound having a photopolymerization initiating group, wherein the epoxy functional group equivalent X of the polymer compound (A) is 100 g / eq < X < 400 g / eq, thereby achieving excellent scratch resistance at high temperatures.

[0030] The reason why the above-mentioned effects are obtained by the above-mentioned photocurable resin sheet is presumed to be as follows.

[0031] By using a high molecular compound (polymer) with a low epoxy functional group equivalent, i.e., a high molecular compound with a large epoxy group weight, the crosslinking density of the cured product increases, the glass transition temperature and elastic modulus after curing increase, and the temperature dependence of the elastic modulus decreases, and a high elastic modulus is maintained even at high temperatures, so a high elastic modulus is obtained even at high temperatures, and the scratch resistance is improved even at high temperatures. Therefore, the optical material obtained from the photocurable resin sheet of the present invention has excellent scratch resistance at high temperatures.

[0032] In addition, the photocurable resin sheet of the present invention does not become liquid at room temperature and maintains its shape even before curing, so it is excellent in operability, photocurability and transparency. In addition, the molding property and workability such as batch sealing (sealing) and control of micro thickness become easy, and the product productivity is also improved.

[0033] (A) Polymer compound having an epoxy group (also referred to as polymer compound (A))

[0034] The epoxy functional group equivalent X of the polymer compound (A) is 100 g / eq<X<400 g / eq, preferably 125 g / eq~375 g / eq, more preferably 150 g / eq~350 g / eq. The upper limit is more preferably 300 g / eq, and particularly preferably 250 g / eq. Here, in this specification, the expression "~" means more than the value before the description such as "~" and less than the value after the description such as "~".

[0035] When the epoxy functional group equivalent is 100 g / eq or less, the density of the epoxy group is too high, so sometimes the reaction cannot be completely carried out due to steric hindrance between the side chains. When the epoxy functional group equivalent is 400 g / eq or more, the amount of epoxy group is small, so sufficient scratch resistance at high temperature cannot be obtained.

[0036] In this specification, the epoxy functional group equivalent of the polymer compound (A) is measured in accordance with JIS K7236 (2001).

[0037] The weight average molecular weight of the polymer compound (A) is not particularly limited, but is preferably 1,000 to 1,000,000, and more preferably 10,000 to 100,000. When the weight average molecular weight of the polymer compound (A) is within the above range, the shape of the sheet can be more appropriately maintained. The polymer compound (A) may be used alone or in combination of two or more.

[0038] In the present specification, the weight average molecular weight of a polymer compound is a value obtained by dissolving the polymer compound in tetrahydrofuran and measuring using a GPC apparatus (HLC-8320 GPC manufactured by Tosoh Corporation) under the following conditions and converting the result to polystyrene.

[0039] Column: TSKgel Super HZMH / HZ4000 / HZ3000 / HZ2000

[0040] Column size: 6.0mm I.D.×150mm

[0041] Eluent: THF

[0042] Flow rate: 0.6mL / min

[0043] Detector: RI

[0044] Column temperature: 40°C

[0045] Injection volume: 20 μL

[0046] The larger the storage modulus G' of the polymer compound (A) at 30°C, the greater the glass transition temperature and elastic modulus of the photocurable resin sheet after curing. Therefore, it is preferably 1000000 Pa or more, more preferably 1100000 Pa or more, further preferably 1200000 Pa or more, particularly preferably 1500000 Pa or more, most preferably 1750000 Pa or more, and further preferably 2000000 Pa or more. There is no particular upper limit, for example, it is 10000000 Pa or less.

[0047] In addition, in this specification, the storage modulus G' of the polymer compound at 30°C is measured at 30°C using a dynamic viscoelasticity measuring apparatus under the following measuring conditions.

[0048] Sample size: diameter 8mmΦ, thickness 250μm

[0049] Measurement mode: Shear oscillation

[0050] Frequency: 1Hz

[0051] The polymer compound (A) is not particularly limited. In order to further increase the glass transition temperature and elastic modulus after curing the photocurable resin sheet, there is no particular limitation as long as it is a resin obtained by polymerizing a vinyl monomer. For example, poly(meth)acrylic acid resins, vinyl resins, olefin resins, acrylonitrile resins, and copolymers thereof can be cited. The polymer compound (A) can be used alone or in combination of two or more. Among them, poly(meth)acrylic acid resins are preferred because of their superior scratch resistance at high temperatures.

[0052] Examples of poly(meth)acrylic resins include polymers obtained by polymerizing (meth)acrylic acid esters such as (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters as monomers. It should be noted that in this specification, "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid".

[0053] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, and eicosyl acrylate. Examples of the cycloalkyl (meth)acrylate include cyclopentyl (meth)acrylate and cyclohexyl (meth)acrylate. Examples of the aryl (meth)acrylate include phenyl (meth)acrylate, benzyl (meth)acrylate, etc. These (meth)acrylates may be used alone or in combination of two or more.

[0054] The poly(meth)acrylic resin can copolymerize other monomers that can copolymerize with the above-mentioned (meth)acrylate. As other monomers, for example, carboxyl-containing monomers, anhydride monomers, hydroxyl-containing monomers, sulfonic acid-containing monomers, phosphoric acid-containing monomers, acrylamide, acrylonitrile, etc. can be listed. As carboxyl-containing monomers, for example, (meth)acrylic acid, (meth)carboxyethyl acrylate, (meth)carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, etc. can be listed. As anhydride monomers, for example, maleic anhydride and itaconic anhydride can be listed. As hydroxyl-containing monomers, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (meth)acrylate (4-hydroxymethylcyclohexyl)methyl, etc. can be listed. Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, (meth)acryloyloxynaphthalenesulfonic acid, etc. Examples of the phosphoric acid group-containing monomer include 2-hydroxyethylacryloyl phosphate, etc. These other monomers may be used alone or in combination of two or more.

[0055] The polymerization method of the poly(meth)acrylic acid resin is not particularly limited, and examples thereof include solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization.

[0056] Examples of the vinyl resin include vinyl chloride resin, vinyl acetate resin, poly(vinyl alcohol), etc. Examples of the olefin resin include polyethylene, polypropylene, and ethylene-propylene copolymer. These resins may be used alone or in combination of two or more.

[0057] The polymer compound (A) has an epoxy group, preferably an aliphatic epoxy group, and more preferably a (meth) acrylate glycidyl group. In addition, the polymer compound (A) may have a functional group other than the epoxy group. As functional groups other than the epoxy group, for example, a carboxyl group, an alkyl group, etc. can be cited. In addition, the polymer compound (A) may have a photopolymerization initiating group. In addition, the polymer compound (A) preferably does not have an oxetane group.

[0058] When the polymer compound (A) is a polymer compound obtained by radical polymerization such as a poly(meth)acrylic resin, the method for introducing an epoxy group is not particularly limited, and examples thereof include a method of copolymerizing a monomer having an epoxy group with the various monomers described above.

[0059] Examples of the monomer having an epoxy group include a monomer having an aliphatic epoxy group, a monomer having an alicyclic epoxy group, and a monomer having an aromatic epoxy group. Among them, a monomer having an aliphatic epoxy group is preferred.

[0060] Examples of the monomer having an aliphatic epoxy group include glycidyl ethers of polyols such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, triglycidyl ether of glycerol, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, and diglycidyl ether of polypropylene glycol; polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to an aliphatic polyol such as propylene glycol, trimethylolpropane, and glycerol; diglycidyl esters of aliphatic long-chain dibasic acids, monoglycidyl ethers of aliphatic higher alcohols, glycidyl esters of higher fatty acids, and (meth)acrylates of aliphatic epoxy compounds such as epoxidized soybean oil, octyl epoxystearate, butyl epoxystearate, epoxidized soybean oil, and epoxidized polybutadiene. Specific examples thereof include epoxy group-containing (meth)acrylates such as 4-hydroxybutyl (meth)acrylate glycidyl ether and glycidyl (meth)acrylate. These may be used alone or in combination of two or more.

[0061] Examples of the monomer having an alicyclic epoxy group include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexylcarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexylcarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexylcarboxylate, and bis(3,4-epoxycyclohexylmethyl)hexanoate. (Meth)acrylates of alicyclic epoxy compounds such as esters, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, methylenebis(3,4-epoxycyclohexane), propane-2,2-diyl-bis(3,4-epoxycyclohexane), 2,2-bis(3,4-epoxycyclohexyl)propane dicyclopentadiene diepoxide, ethylenebis(3,4-epoxycyclohexanecarboxylate), 1-epoxyethyl-3,4-epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane, caprolactone-modified products thereof, trimethyl caprolactone-modified products thereof, and valerolactone-modified products thereof. These may be used alone or in combination of two or more.

[0062] Examples of the monomer having an aromatic epoxy group include (meth)acrylates of aromatic epoxy compounds such as monoglycidyl ether of polyether alcohol obtained by adding alkylene oxide to phenol, cresol or butylphenol. These monomers may be used alone or in combination of two or more.

[0063] The content of the polymer compound (A) in the photocurable resin sheet of the present invention is not particularly limited, but is preferably 85% to 99% by mass, more preferably 88% to 99% by mass, further preferably 92% to 99% by mass, and particularly preferably 95% to 99% by mass. When the content of the polymer compound (A) in the photocurable resin sheet is within the above range, the scratch resistance at high temperature can be more appropriately obtained, and the sheet shape can be more appropriately maintained at room temperature.

[0064] (B) Low molecular weight compound having a photopolymerization initiating group (also referred to as low molecular weight compound (B))

[0065] The upper limit of the molecular weight of the low molecular weight compound (B) is not particularly limited, preferably less than 1000, more preferably 800 or less, and further preferably 700 or less. When the molecular weight is 1000 or more, the diffusion rate in the system slows down, sometimes hindering the photocurability. The lower limit is also not particularly limited, preferably 100 or more, more preferably 400 or more. The low molecular weight compound (B) can be used alone or in combination of two or more.

[0066] It should be noted that, in this specification, the molecular weight of a low molecular weight compound is a value calculated from the molecular structure of the compound. Here, in this specification, the molecular structure of the compound is determined by NMR.

[0067] As the low molecular weight compound (B) having a photopolymerization initiating group, there is no particular limitation as long as it contains a group having the property of generating ion pairs or free radicals by light absorption, and examples thereof include a photocationic polymerization initiator having a photocationic polymerization initiating group, a photoradical polymerization initiator having a photoradical generating group, etc. The low molecular weight compound (B) can be used alone or in combination of two or more.

[0068] Photocationic polymerization initiator generates cationic species or Lewis acid by irradiating active energy rays such as visible light, ultraviolet rays, X-rays, electron beams, and initiates polymerization reactions of epoxy groups and oxetane groups. As photocationic polymerization initiator, photoacid generator, photobase generator, etc. are preferred, and photoacid generator is more preferred. In the case of using visible light as active energy ray, it is particularly preferred to use a photocationic polymerization initiator that is highly sensitive to light above 380nm. Photocationic polymerization initiator is usually a compound that shows maximum absorption in a wavelength region near 300nm or shorter than it, so by cooperating with a photosensitizer that shows maximum absorption in a wavelength region longer than 300nm, specifically, in light of a wavelength longer than 380nm, it is possible to sense light of the wavelength near this, and promote the generation of cationic species or acid from the photocationic polymerization initiator.

[0069] As the photoacid generator, an onium salt containing an anion component and a cationic component can be cited. As the onium cationic component, for example, aromatic diazo onium, aromatic sulfonium, aromatic iodonium, aromatic selenium, aromatic pyridinium, aromatic dicyclopentadienyl, aromatic phosphonium, etc. can be cited. They can be used alone or in combination of two or more. Among them, aromatic sulfonium is preferred.

[0070] Examples of anionic components include PF6 - PF4(CF2CF3)2 - 、SbF6 - 、AsF6 - 、SbCl6 - 、BiCl5 - 、SnCl6 - 、ClO4 - , dithiocarbamate anion, SCN - , trifluoromethanesulfonate, etc. They can be used alone or in combination of two or more. Among them, PF6 - 、SbF6 - and AsF6 - , more preferably PF6- and SbF6 - .

[0071] The low molecular weight compound (B) having a photopolymerization initiating group is preferably a photocationic polymerization initiator, more preferably a photoacid generator, and further preferably an aromatic sulfonium.

[0072] The low molecular compound (B) having a photopolymerization initiating group may have a functional group other than the photopolymerization initiating group. As the functional group other than the photopolymerization initiating group, for example, a carboxyl group, an alkyl group, etc. can be cited. In addition, the low molecular compound (B) may have an epoxy group. In addition, the low molecular compound (B) preferably does not have an oxetane group.

[0073] The content of the low molecular weight compound (B) having a photopolymerization initiation group in the photocurable resin sheet of the present invention is not particularly limited, but is preferably 0.5% to 15% by mass, more preferably 1% to 12% by mass, further preferably 1% to 8% by mass, particularly preferably 1% to 5% by mass, and most preferably 1% to 3% by mass. When the content of the low molecular weight compound (B) is within the above range, scratch resistance at high temperature can be more appropriately obtained, and good photocurability can be more appropriately imparted, and in addition, bleeding to the sheet surface can be more appropriately suppressed, and there is a tendency that the workability also becomes better.

[0074] The total content of the polymer compound (A) and the low molecular weight compound (B) in the photocurable resin sheet of the present invention is preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 98% by mass or more, particularly preferably 99% by mass or more, and may be 100% by mass.

[0075] The photocurable resin sheet of the present invention may contain a low molecular weight compound (B) having a photopolymerization initiating group and a compound having an oxetane group (preferably a low molecular weight compound having an oxetane group). Here, the molecular weight of the low molecular weight compound having an oxetane group is the same as that of the low molecular weight compound (B).

[0076] Examples of the low molecular weight compound having an oxetanyl group include 3-ethyl-3{[(3-ethyloxetanyl-3-yl)methoxy]methyl}oxetane, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, di[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, phenol novolac oxetane, isobutoxymethyl (3-ethyl-3-oxetane methyl) ether, isobornyloxyethyl (3-ethyl-3-oxetane methyl) ether, isobornyl (3-ethyl-3-oxetane methyl) ether, 2-ethylhexyl (3-ethyl-3-oxetane methyl) ether, ethyl diethylene glycol (3-ethyl-3-oxetane methyl) ether, di[1-ethyl (3-oxetane 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane, ethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, tricyclodecanediyl dimethylene(3-ethyl-3-oxetanylmethyl)ether, trimethylolpropane tris(3-ethyl-3-oxetanylmethyl)ether, 1,4-bis(3-ethyl-3-oxetanylmethoxy)methyl Heterocyclobutyl methoxy) butane, 1,6-bis (3-ethyl -3-oxetanyl methoxy) hexane, pentaerythritol tris (3-ethyl -3-oxetanyl methyl) ether, pentaerythritol tetrakis (3-ethyl -3-oxetanyl methyl) ether, polyethylene glycol bis (3-ethyl -3-oxetanyl methyl) ether, dipentaerythritol hexa (3-ethyl -3-oxetanyl methyl) ether, dipentaerythritol penta (3-ethyl -3-oxetanyl methyl) ether, dipentaerythritol tetrakis (3-ethyl -3-oxetanyl methyl) ether, etc. They can be used alone or in combination of two or more. Among them, preferably 3-ethyl -3{[(3-ethyl oxetanyl -3-yl) methoxy] methyl} oxetane.

[0077] Since a high molecular weight compound (A) having a low epoxy functional group equivalent is used in the present invention, the curing reaction proceeds sufficiently even if a compound having an oxetane group is not contained. Therefore, the content of the compound having an oxetane group (preferably a low molecular weight compound having an oxetane group) in the photocurable resin sheet is preferably 1.0% by mass or less, more preferably less than 0.5% by mass, further preferably 0.3% by mass or less, particularly preferably 0.1% by mass or less, most preferably 0.01% by mass or less, and most preferably 0% by mass (not contained).

[0078] In the range that does not hinder the effect of the present invention, in addition to the polymer compound (A) and the low molecular compound (B), the photocurable resin sheet of the present invention may also contain other components. As other components, for example, in addition to the above-mentioned low molecular compound having an oxetane group, photosensitizers, colorants, etc. can be listed. They can be used alone or in combination of two or more.

[0079] As photosensitizers, for example, anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreduction pigments, etc. can be listed. They can be used alone or in combination of two or more. Anthracene compounds with excellent photosensitizing effects are particularly preferred. The content of the photosensitizer is preferably 0.1% to 5% by mass, more preferably 0.5% to 3% by mass.

[0080] The photocurable resin sheet of the present invention is preferably irradiated with 500 mJ / cm 2 The glass transition temperature of the cured product obtained by light curing with ultraviolet rays and then heating at 150°C for 15 minutes is 100°C or above, or the glass transition temperature cannot be measured. The higher the glass transition temperature of the cured product, the better the scratch resistance at high temperature. Therefore, the higher the glass transition temperature of the cured product, the better. It is more preferably 105°C or above, further preferably 110°C or above, particularly preferably 115°C or above, most preferably 120°C or above, most preferably 130°C or above, further most preferably 140°C or above, and particularly most preferably 150°C or above. The upper limit is not particularly limited, for example, it is 300°C or below.

[0081] In this specification, the glass transition temperature of a cured product is the peak temperature (tan δ peak temperature) in a temperature distribution curve obtained by measuring tan δ in a predetermined temperature range of the cured product using a dynamic viscoelasticity measuring apparatus, and is specifically measured by the method described in Examples.

[0082] In addition, the inability to measure the glass transition temperature of the cured product means that: in the above-mentioned temperature range, tan δ does not show a maximum value, tan δ shows a maximum value at the upper limit temperature of the above-mentioned temperature range, etc., which indicates that the glass transition temperature is a temperature higher than the upper limit temperature of the above-mentioned temperature range; the sample breaks during measurement; or the cured product does not have a glass transition temperature at all, such as a perfect elastic body. In particular, it means that the glass transition temperature is a temperature higher than the upper limit temperature of the above-mentioned temperature range, or the sample breaks during measurement.

[0083] The upper limit temperature of the predetermined temperature range is preferably 200°C.

[0084] In the above test, the sample fracture during measurement refers to the presence of cracks or microscopic voids in the measurement sample.

[0085] The fact that the glass transition temperature of the cured product is 100° C. or higher or the glass transition temperature cannot be measured means that the glass transition temperature of the cured product is high. Such a cured product can be preferably obtained by the photocurable resin sheet of the present invention containing a polymer compound (A) having a low epoxy functional group equivalent.

[0086] The photocurable resin sheet of the present invention is irradiated with 500 mJ / cm 2 The light transmittance of the cured product obtained by photocuring with ultraviolet rays and heating at 150°C for 15 minutes at a wavelength of 400nm at 25°C is preferably 70% or more, more preferably 80% or more. The upper limit is not particularly limited, but is preferably 99% or less. When the light transmittance is less than 70%, the transparency is insufficient and it is sometimes not usable for optical purposes. The light transmittance can be measured using a spectrophotometer.

[0087] By suppressing the light absorption in the ultraviolet region of the raw materials used, the light transmittance at a wavelength of 400 nm can be adjusted to the above-mentioned numerical range.

[0088] The photocurable resin sheet of the present invention is irradiated with 500 mJ / cm 2 The refractive index of the cured product obtained by photocuring with ultraviolet rays and heating at 150°C for 15 minutes at 25°C for light of a wavelength of 589nm has different preferred ranges depending on the use of the photocurable resin sheet. For example, when the photocurable resin sheet of the present invention is used for a lens, the refractive index is preferably 1.40 or more, more preferably 1.47 or more. There is no particular upper limit, but it is preferably 1.80 or less. The refractive index can be measured using a refractometer.

[0089] By adjusting the refractive index of the raw materials used and their mixing ratio, the refractive index for light with a wavelength of 589 nm can be adjusted to the above-mentioned numerical range.

[0090] As a specific method for adjusting the above-mentioned transmittance and the above-mentioned refractive index within the above-mentioned numerical range, for example, a material with little light absorption in the ultraviolet region can be used, and the amount of the light-absorbing material (such as a compound containing a photopolymerization initiating group) can be adjusted to a small amount as needed.

[0091] The photocurable resin sheet of the present invention is preferably irradiated with 500 mJ / cm 2 The tensile modulus E' (at 25°C) and the tensile modulus E' (at 150°C) of the cured product obtained by photocuring with ultraviolet rays and then heating at 150°C for 15 minutes satisfy the following formula.

[0092] 1 < E’(at 25°C) / E’(at 150°C) < 10

[0093] E’(at 25°C) / E’(at 150°C) is more preferably 1.25 to 9.75, and further preferably 1.5 to 7.0. The upper limit is particularly preferably 6.0, and most preferably 5.0. When E’(at 25°C) / E’(at 150°C) is within the above range, the change amount of the tensile elastic modulus E’ is smaller at 25°C to 150°C, and the resistance to the temperature cycle test in the reliability evaluation is further improved.

[0094] The cured product obtained by subjecting the photocurable resin sheet of the present invention to heat treatment at 150°C for 15 minutes after photocuring by irradiating ultraviolet rays of 500 mJ / cm 2 The tensile elastic modulus E’ (at 100°C) of the cured product is preferably 200000000 Pa or more at 100°C. The higher the E’ (at 100°C) of the above cured product, the more excellent the scratch resistance at high temperature. Therefore, the higher the E’ (at 100°C) of the above cured product, the better, more preferably 400000000 Pa or more, further preferably 600000000 Pa or more, particularly preferably 800000000 Pa or more, most preferably 1000000000 Pa or more, and even more preferably 1200000000 Pa or more. There is no particular limitation on the upper limit, for example, it is 10000000000 Pa or less.

[0095] The tensile elastic modulus E’ at each temperature of the cured product is measured by the method described in the examples.

[0096] By containing the high molecular compound (A) with a low epoxy functional group equivalent in the photocurable resin sheet of the present invention, E’(at 25°C) / E’(at 150°C) and E’(at 100°C) of the above cured product can be appropriately adjusted to the above numerical ranges.

[0097] The photocurable resin sheet of the present invention can be made by casting a photocurable resin composition containing the above-mentioned polymer compound (A) and the low molecular compound (B) and a solvent as needed onto a substrate, and drying the solvent as needed. In addition, the photocurable resin composition containing the above-mentioned polymer compound (A) and the low molecular compound (B) can also be processed into a film with a roller, or extruded into a film from a T-die. Then, when a substrate is used, the substrate can be peeled off or not. In addition, it is also possible to further overlap another substrate on the photocurable resin sheet manufactured on the substrate, thereby making a photocurable resin sheet in a state sandwiched between the substrates. In this case, by winding the photocurable resin sheet into a winding body, it can be made into a roll. In addition, sheets cut to a specified size can also be overlapped to make a single sheet.

[0098] As a solvent, there is no particular limitation, for example, esters such as ethyl lactate, methyl acetate, and butyl acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; polar solvents such as dimethylformamide and dimethyl sulfoxide; halogen solvents such as 1,1,1-trichloroethane and chloroform; ethers such as tetrahydrofuran and dioxane; aromatics such as benzene, toluene, and xylene; fluorinated inert liquids such as perfluorooctane and perfluorotri-n-butylamine, etc. They can be used alone or in combination of two or more. Among them, methyl ethyl ketone is preferred from the viewpoint of compatibility with the solute.

[0099] When the photocurable resin composition contains a solvent, the content of the solvent is not particularly limited, but is preferably 20 to 50 parts by mass based on 100 parts by mass of the total mass of the polymer compound (A) and the low molecular weight compound (B).

[0100] The substrate is, for example, a plastic substrate, and a plastic film can be used appropriately. The material of the plastic substrate is not particularly limited, and for example, polyolefins, polyesters, polyurethanes, polycarbonates, polyetheretherketones, polyimides, polyetherimides, polyamides, fully aromatic polyamides, polyvinyl chloride, polyvinylidene chloride, polyphenylene sulfide, aromatic polyamides, fluorine-containing resins, cellulose resins, silicone resins, etc. can be cited. As polyolefins, for example, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymers, ionomer resins, ethylene-(methyl) acrylic acid copolymers, ethylene-(methyl) acrylic acid ester copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, etc. can be cited. As polyesters, for example, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc. can be cited. These materials can be used alone or in combination of two or more. The substrate may have a single-layer structure or a multi-layer structure. In addition, the substrate preferably has light transparency.

[0101] Examples of substrates other than plastic substrates include porous substrates, rubber sheets, foam sheets, metal foils, and laminates thereof, which may be used alone or in combination of two or more.

[0102] Examples of the porous material forming the porous material substrate include paper such as Japanese paper, kraft paper, glassine paper, premium paper, synthetic paper, and topcoat paper; and cloth such as woven cloth and nonwoven cloth.

[0103] Examples of fiber materials for forming cloths include natural fibers, semisynthetic fibers, and synthetic fibers. Specific examples include cotton fibers, staple fibers, Manila hemp, pulp, rayon, acetate fibers, polyester fibers, polyvinyl alcohol fibers, polyamide fibers, and polyolefin fibers.

[0104] Examples of the rubber constituting the rubber sheet include natural rubber and butyl rubber.

[0105] Examples of the foam constituting the foam sheet include polyurethane foam and polychloroprene rubber foam.

[0106] Examples of the metal foil include aluminum foil and copper foil.

[0107] In the substrate, various additives such as fillers (inorganic fillers, organic fillers, etc.), anti-aging agents, antioxidants, ultraviolet absorbers, lubricants, plasticizers, colorants (pigments, dyes, etc.) can be added as needed. The surface of the substrate can be subjected to surface treatment. As surface treatment, for example, physical treatments such as corona treatment and plasma treatment, chemical treatments such as primer treatment and back treatment can be cited.

[0108] The thickness of the substrate is, for example, 1 μm to 200 μm.

[0109] The photocurable resin sheet of the present invention can be cured by light irradiation such as ultraviolet light (e.g., wavelength of about 365 nm). As the light source of light irradiation, LED, low-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, xenon lamp, etc. can be used. The irradiation dose is not particularly limited, but is preferably 100 mJ / cm 2 ~10000mJ / cm 2 In addition, a heat curing step may be performed as necessary. Examples of heating conditions include conditions of 120° C. to 180° C. for 5 minutes to 60 minutes.

[0110] The thickness of the photocurable resin sheet of the present invention (excluding the thickness of the substrate) is preferably 10 μm to 1000 μm, more preferably 50 μm to 500 μm. When the thickness of the photocurable resin sheet is less than 10 μm, the workability may be impaired, and when the thickness of the photocurable resin sheet is greater than 1000 μm, the photocurability may be impaired.

[0111] The shape of the photocurable resin sheet of the present invention is not particularly limited, and may be, for example, a polygon including a square and a rectangle, a circle, an ellipse, or a strip. The polygonal, circular, or ellipse photocurable resin sheet is circulated in the form of a single sheet, and the strip-shaped photocurable resin sheet can be circulated in the form of a winding body (roll) wound on a winding core. The width of the strip-shaped photocurable resin sheet and the width of the winding body obtained by winding the strip-shaped photocurable resin sheet can be freely set.

[0112] Figure 1 The photocurable resin sheet 1 shown is a single layer. In the present invention, other layers may be arranged on the main surface 2A and / or the main surface 2B of the photocurable resin sheet 1. That is, the photocurable resin sheet of the present invention may be a photocurable resin sheet laminate.

[0113] As an example of a photocurable resin sheet laminate, for example, a photocurable resin sheet (also referred to as a resin sheet) of the present invention has a release liner on at least one side of the surface. That is, the photocurable resin sheet laminate may have a release liner on one side of the photocurable resin sheet of the present invention, or may have a release liner on both sides of the photocurable resin sheet of the present invention. In the photocurable resin sheet laminate, the resin sheet and the release liner are typically directly laminated.

[0114] Examples of the photocurable resin sheet laminate of the present invention in such an embodiment include a laminate having a structure of [resin sheet] / [release liner] and a laminate having a structure of [release liner] / [resin sheet] / [release liner]. Figure 2 In the photocurable resin sheet laminate 10 shown in (A), a release liner 3 is laminated on a photocurable resin sheet 1. Figure 2 In the photocurable resin sheet laminate 10 shown in (B), the photocurable resin sheet 1 is laminated on the release liner 3 , and the release liner 3 is laminated on the photocurable resin sheet 1 .

[0115] As the release liner, any appropriate release liner can be used as long as it is a release liner that can be generally applied to adhesive sheets, within the scope of not impairing the effect of the present invention. As such a release liner, for example, a substrate having a release treatment layer, a low-adhesive substrate containing a fluorine-containing polymer, and a low-adhesive substrate containing a non-polar polymer can be cited.

[0116] Examples of the substrate having a release-treated layer include plastic films and papers whose surfaces have been treated with a release-treated agent such as silicone-based, long-chain alkyl-based, fluorine-containing, or molybdenum sulfide-based.

[0117] Examples of the plastic film include the same ones as those mentioned above with respect to the substrate.

[0118] Examples of the fluorine-containing polymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer. These may be used alone or in combination of two or more.

[0119] Examples of the nonpolar polymer include olefin resins such as polyethylene and polypropylene, which may be used alone or in combination of two or more.

[0120] The surface of the release liner may be subjected to various treatments such as mold release treatment, antifouling treatment, and antistatic treatment. For mold release treatment, silicone-based mold release agents, fluorine-containing mold release agents, long-chain alkyl-based mold release agents, fatty acid amide-based mold release agents, and silica powder may be used. For antifouling treatment, silica powder may be used. For antistatic treatment, coating-type antistatic treatment, kneading-type antistatic treatment, and vapor deposition-type antistatic treatment may be used.

[0121] The thickness of the release liner is preferably 5 μm to 200 μm, more preferably 5 μm to 100 μm. The thickness of the release liner is not included in the thickness of the photocurable resin sheet of the present invention.

[0122] As another example of a photocurable resin sheet laminate, for example, a substrate layer is provided on at least one side of the photocurable resin sheet (also referred to as a resin sheet) of the present invention. That is, in the photocurable resin sheet laminate, a substrate layer may be provided on one side of the photocurable resin sheet of the present invention, or a substrate layer may be provided on both sides of the photocurable resin sheet of the present invention. In the photocurable resin sheet laminate, the resin sheet and the substrate layer are typically directly laminated.

[0123] As such an embodiment of the photocurable resin sheet laminate of the present invention, for example, a laminate having a structure of [resin sheet] / [base layer] and a laminate having a structure of [base layer] / [resin sheet] / [base layer] are mentioned. Figure 3 In the photocurable resin sheet laminate 10 shown in (A), a base material layer 4 is laminated on a photocurable resin sheet 1. Figure 3 In the photocurable resin sheet laminate 10 shown in (B), the photocurable resin sheet 1 is laminated on the base material layer 4 , and the base material layer 4 is laminated on the photocurable resin sheet 1 .

[0124] As the substrate layer, a substrate layer including any appropriate substrate can be adopted within a range not impairing the effects of the present invention. Examples of such a substrate include the above-mentioned substrates.

[0125] As another example of a photocurable resin sheet laminate, for example, the photocurable resin sheet of the present invention (also referred to as a resin sheet) has a substrate layer on one side and a release liner on the other side. As such an embodiment of the photocurable resin sheet laminate of the present invention, for example, a laminate having a structure of [substrate layer] / [resin sheet] / [release liner] can be cited.

[0126] As another example of a photocurable resin sheet laminate, for example, a substrate layer is provided on one side of the photocurable resin sheet (also referred to as a resin sheet) of the present invention, and an adhesive layer is provided on the side of the substrate layer opposite to the resin sheet. As such an embodiment of the photocurable resin sheet laminate of the present invention, for example, a laminate having a structure of [resin sheet] / [substrate layer] / [adhesive layer] can be cited.

[0127] As the adhesive layer, any appropriate adhesive layer may be adopted within the range not impairing the effects of the present invention, and examples of such adhesive layers include acrylic adhesive layers, urethane adhesive layers, olefin adhesive layers, rubber adhesive layers, and silicone adhesive layers.

[0128] Although several examples have been given and described about the photocurable resin sheet laminate, the photocurable resin sheet laminate is not particularly limited as long as it is a laminate containing the photocurable resin sheet of the present invention.

[0129] The photocurable resin sheet and the photocurable resin sheet laminate of the present invention may be made into a roll shape by winding the photocurable resin sheet and the photocurable resin sheet laminate into a roll.

[0130] exist Figure 4 In the embodiment, the photocurable resin sheet 1 is wound into a roll (roll) 11 .

[0131] The optical material of the present invention is characterized in that it is obtained by curing the photocurable resin sheet of the present invention. As the photocurable resin sheet of the present invention, a photocurable resin sheet laminate can be used.

[0132] The optical material is not particularly limited, and examples thereof include optical electronic parts such as displays and adhesives for optical semiconductors, lenses, and protective films.

[0133] The photocurable resin sheet of the present invention has thermoplasticity before curing, and has excellent scratch resistance at high temperature after curing, so it can be suitable for use in imprint molding (preferably nanoimprint molding). Therefore, the optical material of the present invention is preferably a material obtained by imprint molding the photocurable resin sheet of the present invention, and more preferably a material obtained by nanoimprint molding the photocurable resin sheet of the present invention. As a material obtained by nanoimprint molding the photocurable resin sheet of the present invention, for example, microlenses, optical diffraction elements, surface relief diffraction gratings, etc. can be cited. Among them, microlenses are preferred.

[0134] In the imprint molding, a mold having a predetermined concave-convex structure (pattern) is pressed against the photocurable resin sheet of the present invention, and the photocurable resin sheet of the present invention is cured by heat, ultraviolet light, or the like, so that the concave-convex structure of the mold is transferred to the photocurable resin sheet of the present invention, thereby manufacturing a photocurable resin sheet having a concave-convex structure. In addition, after the photocurable resin sheet is cured, the photocurable resin sheet may be subjected to a heat treatment as required. There are no particular restrictions on the amount of ultraviolet irradiation and the heating conditions during molding, and they are the same as described above.

[0135] In imprint molding and nanoimprint molding, except for the size of the concave-convex structure formed on the mold, the molding is basically the same. In nanoimprint molding, as the concave-convex structure, a finer concave-convex structure such as a nanometer size (nano concave-convex structure) is used. In addition, the method for making the concave-convex structure of the mold can adopt a known method.

[0136] Example

[0137] Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Hereinafter, "parts" or "%" means "parts by mass" or "% by mass", respectively, unless otherwise specified.

[0138] Materials used in Examples and Comparative Examples are listed below.

[0139] ·Polymer compound (A)

[0140] Epoxy-containing (meth)acrylic resin 1 (1HM2097 manufactured by Daisei Fine Chemicals Co., Ltd., weight average molecular weight 60,000, epoxy functional group equivalent 187 g / eq, storage modulus G' at 30°C 2,100,000 Pa, (meth)acrylic resin having an aliphatic epoxy group (glycidyl (meth)acrylate group))

[0141] Epoxy-containing (meth)acrylic resin 2 (1HM2095 manufactured by Daisei Fine Chemicals Co., Ltd., weight average molecular weight 60,000, epoxy functional group equivalent 306 g / eq, storage modulus G' at 30°C 1,300,000 Pa, (meth)acrylic resin having an aliphatic epoxy group (glycidyl (meth)acrylate group))

[0142] Epoxy-containing (meth)acrylic resin 3 (1HM2067 manufactured by Daisei Fine Chemicals Co., Ltd., weight average molecular weight 60,000, epoxy functional group equivalent 433 g / eq, storage modulus G' at 30°C 820,000 Pa, (meth)acrylic resin having an aliphatic epoxy group (glycidyl (meth)acrylate group))

[0143] Low molecular weight compounds (B)

[0144] Compound containing a photopolymerization initiating group (triarylsulfonium salt, CPI101A manufactured by San-Apro Co., Ltd., molecular weight 558, anion: SbF6 - )

[0145] Low molecular weight compounds other than low molecular weight compounds (B)

[0146] Oxetane-containing compound (3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, OXT221 manufactured by Toagosei Co., Ltd., molecular weight 214)

[0147] Examples 1 to 4 and Comparative Examples 1 and 2

[0148] Each component was dissolved in methyl ethyl ketone at the ratio (solid content ratio) shown in Table 1 to obtain a photocurable resin composition. A PET film was used as a substrate, and the photocurable resin composition was cast on the substrate and dried to obtain a photocurable resin sheet with a thickness of about 100 μm. The obtained photocurable resin sheet was evaluated by the following method. The evaluation results are shown in Table 1.

[0149] <Glass transition temperature>

[0150] The photocurable resin sheets obtained in the examples and comparative examples were irradiated with 500 mJ / cm 2After light curing with ultraviolet rays, heat treatment (post-curing) was performed at 150°C for 15 minutes. Regarding the glass transition temperature of the obtained cured product, the dynamic viscoelasticity measuring device RSA-3 manufactured by TA Instruments was used to measure tanδ in the temperature range of 25°C to 200°C under the following measuring conditions, and the temperature of the peak in the obtained temperature distribution curve (tanδ peak temperature) was measured as the glass transition temperature.

[0151] Sample size: 1cm×5cm, thickness 50μm~150μm

[0152] Measurement mode: Stretch mode

[0153] Frequency: 1Hz

[0154] Heating rate: 10℃ / min

[0155] <Tensile elastic modulus E'>

[0156] The photocurable resin sheets obtained in the examples and comparative examples were irradiated with 500 mJ / cm 2 After light curing with ultraviolet rays, heat treatment (post-curing) was performed at 150°C for 15 minutes. The tensile elastic modulus E' of the obtained cured product was measured at 25°C, 100°C, and 150°C using a dynamic viscoelasticity measuring device RSA-3 manufactured by TA Instruments under the following measuring conditions.

[0157] Sample size: 1cm×5cm, thickness 50μm~150μm

[0158] Measurement mode: Stretch mode

[0159] Frequency: 1Hz

[0160] <Light transmittance>

[0161] The photocurable resin sheets obtained in the examples and comparative examples were irradiated with 500 mJ / cm 2 After photocuring with ultraviolet rays of 1000 nm, the resulting product was heated at 150° C. for 15 minutes (post-curing). The light transmittance (wavelength 400 nm) of the resulting cured product at 25° C. was measured using a spectrophotometer (manufactured by JASCO Corporation).

[0162] <Refractive Index>

[0163] The photocurable resin sheets obtained in the examples and comparative examples were irradiated with 500 mJ / cm 2After photocuring with ultraviolet rays, heat treatment (post-curing) was performed at 150° C. for 15 minutes. The refractive index of the obtained cured product to sodium D line (light with a wavelength of 589 nm) was measured at 25° C. using a refractometer (manufactured by Atago Co., Ltd.).

[0164] <Scratch resistance at high temperature (pencil scratch test at 100°C)>

[0165] The photocurable resin sheets obtained in the examples and comparative examples were irradiated with 500 mJ / cm 2 After light curing with ultraviolet light, heat treatment (post-curing) was performed at 150°C for 15 minutes. The obtained cured product was placed on a hot plate at 100°C, and the scratch resistance at high temperature was evaluated by the number of damage or cracks on the surface of the sheet when scratched 10 times with a pencil of hardness HB according to the method of JIS K5600-5-4. The evaluation criteria are as follows.

[0166] 0:0~5 times

[0167] ×: 6 to 10 times

[0168]

[0169] As can be seen from Table 1, in the examples containing (A) a polymer compound having an epoxy group and (B) a low molecular weight compound having a photopolymerization initiating group, and wherein the epoxy functional group equivalent X of the polymer compound (A) is 100 g / eq<X<400 g / eq, the scratch resistance at high temperature is excellent.

[0170] Industrial Applicability

[0171] The present invention relates to a photocurable resin sheet which can be used for optical electronic parts such as adhesives for displays and optical semiconductors, lenses, and protective films.

[0172] Description of symbols

[0173] 1. Photocurable resin sheet

[0174] 2A main surface

[0175] 2B Main surface

[0176] 3 Release liner

[0177] 4 base material layer

[0178] 10 Photocurable resin sheet laminate

[0179] 11 winding body (reel)

Claims

1. A photocurable resin sheet, wherein: The photocurable resin sheet contains: (A) a polymer compound having an epoxy group and (B) a low-molecular compound having a photopolymerization initiating group, and the epoxy functional group equivalent X of the polymer compound (A) is 100 g / eq < X < 400 g / eq.

2. The photocurable resin sheet according to claim 1, wherein The weight-average molecular weight of the polymer compound (A) is 1,000 to 1,000,000.

3. The photocurable resin sheet according to claim 1, wherein The molecular weight of the low-molecular compound (B) is less than 1,000.

4. The photocurable resin sheet according to claim 1, wherein The storage modulus G' of the polymer compound (A) at 30°C is 1,000,000 Pa or more.

5. The photocurable resin sheet according to claim 1, wherein The polymer compound (A) is a resin obtained by polymerizing vinyl monomers.

6. The photocurable resin sheet according to claim 1, wherein The polymer compound (A) is a poly(meth)acrylic resin.

7. The photocurable resin sheet according to claim 1, wherein By irradiating 500mJ / cm 2 The cured product obtained by photocuring with ultraviolet rays and then heating at 150°C for 15 minutes has a light transmittance of 70% or more at a wavelength of 400nm at 25°C and a refractive index of 1.40 or more for light with a wavelength of 589nm.

8. The photocurable resin sheet according to claim 1, wherein By irradiating 500mJ / cm 2 The glass transition temperature of the cured product obtained by photocuring with ultraviolet rays and then heating at 150° C. for 15 minutes is 100° C. or higher, or the glass transition temperature cannot be measured.

9. The photocurable resin sheet according to claim 1, wherein By irradiating 500mJ / cm 2 The tensile modulus of elasticity E' (at 25°C) and the tensile modulus of elasticity E' (at 150°C) at 25°C of the cured product obtained by light curing with ultraviolet rays and heat treatment at 150°C for 15 minutes satisfy the following formula: 1 < E'(at 25°C) / E'(at 150°C) < 10.

10. The photocurable resin sheet according to claim 1, wherein By irradiating 500mJ / cm 2 The cured product obtained by photocuring with ultraviolet rays and then heating at 150° C. for 15 minutes has a tensile elastic modulus E′ (at 100° C.) of 200,000,000 Pa or more at 100° C.

11. The photocurable resin sheet according to claim 1, wherein The photocurable resin sheet is used for optical applications.

12. An optical material, wherein: The optical material is obtained by curing the photocurable resin sheet according to any one of claims 1 to 11.

Images