Polarizing film with adhesive sheet, optical laminate, and image display device

Abstract

This optical film with an adhesive sheet is provided with a photocurable adhesive sheet and an optical film. The adhesive sheet contains a polymer having a constituent unit derived from a nitrogen atom-containing monomer. The optical film with an adhesive sheet is suitable for use in an image display device that may be exposed to a high-temperature environment despite having a photocurable adhesive sheet.

Description

TECHNICAL FIELD

[0001] The present application relates to a polarizing film with an adhesive sheet, an optical laminate, and an image display device. BACKGROUND

[0002] Various image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices generally have an optical laminate including an optical film such as a polarizing film and an adhesive sheet. The optical film contained in the optical laminate is bonded to another optical film, and the optical laminate is bonded to an image display panel, typically using an adhesive sheet. As the adhesive sheet, a sheet obtained by curing a monomer group including an acrylic monomer, a silicone monomer, or the like by polymerization and crosslinking is typical. In Patent Literature 1, a polarizing film with an adhesive sheet is disclosed, which has an adhesive sheet (hereinafter, referred to as a photocurable adhesive sheet) formed of a photocurable composition, and a polarizing film as an optical film. As a type of adhesive sheet other than the photocurable adhesive sheet, there is a heat-cured adhesive sheet formed by curing a layer containing an adhesive composition and a solvent by heat.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2021-56510 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In the case where a photocurable adhesive sheet is used for an optical film with an adhesive sheet, there is a tendency that the quality of an image in an image display device that can be exposed to a high-temperature environment is problematic.

[0008] An object of the present application is to provide an optical film with an adhesive sheet, which is suitable for use in an image display device that can be exposed to a high-temperature environment, although it has a photocurable adhesive sheet.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The present application provides an optical film with an adhesive sheet, which has a photocurable adhesive sheet and an optical film, the adhesive sheet containing a polymer having a constitutional unit derived from a nitrogen atom-containing monomer.

[0011] Further, the present application provides an optical laminate having the above-described optical film with an adhesive sheet.

[0012] Further, the present application provides an image display device having the above-described optical film with an adhesive sheet.

[0013] EFFECTS OF THE INVENTION

[0014] According to the present application, an optical film with an adhesive sheet that is suitable for use in an image display device that can be exposed to a high temperature environment, despite having a photocurable adhesive sheet, can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a cross-sectional view schematically showing an example of the optical film with an adhesive sheet of the present application.

[0016] Figure 2 is a schematic view for explaining an example of a method for forming an adhesive sheet that the optical film with an adhesive sheet of the present application can have.

[0017] Figure 3 is a cross-sectional view schematically showing an example of the optical laminate of the present application.

[0018] Figure 4 is a cross-sectional view schematically showing an example of the optical laminate of the present application.

[0019] Figure 5 is a cross-sectional view schematically showing an example of the optical laminate of the present application.

[0020] Figure 6 is a cross-sectional view schematically showing an example of the image display device of the present application. DETAILED DESCRIPTION

[0021] The optical film with an adhesive sheet of the first aspect of the present application has a photocurable adhesive sheet and an optical film, the adhesive sheet including a polymer having a constitutional unit derived from a nitrogen atom-containing monomer.

[0022] In the second aspect of the present application, for example, in the optical film with an adhesive sheet of the first aspect, the polymer is a (meth)acrylic polymer.

[0023] In the third aspect of the present application, for example, in the optical film with an adhesive sheet of the first or second aspect, the polymer further has a constitutional unit derived from a carboxyl group-containing monomer.

[0024] In the fourth aspect of the present application, for example, in the optical film with an adhesive sheet of any one of the first to third aspects, the weight average molecular weight of the polymer is 600,000 or more, and the polymerization rate of the polymer in the adhesive sheet is 98% or more.

[0025] In the fifth aspect of the present application, for example, in the optical film with an adhesive sheet of any one of the first to fourth aspects, the adhesive sheet includes a silane coupling agent.

[0026] In the sixth aspect of the present application, for example, in the optical film with an adhesive sheet of any one of the first to fifth aspects, the thickness of the adhesive sheet is 30 μm or less.

[0027] In the seventh aspect of the present invention, for example, in the optical film with adhesive sheet in any of the first to sixth aspects, the solvent content in the adhesive sheet is 5% by weight or less.

[0028] In the eighth aspect of the present invention, for example, in the optical film with an adhesive sheet in any of the first to seventh aspects, the adhesive sheet is in contact with the optical film.

[0029] In the ninth aspect of the present invention, for example, in the optical film with adhesive sheet in any of the first to eighth aspects, the optical film is a polarizing film.

[0030] The optical laminate of the tenth embodiment of the present invention comprises an optical film with an adhesive sheet of any one of the first to ninth embodiments.

[0031] The image display device of the eleventh aspect of the present invention includes an optical film with an adhesive sheet of any one of the first to ninth aspects.

[0032] The present invention will now be described in detail, but the present invention is not limited to the following embodiments. Any modifications can be made to implement the invention without departing from the spirit of the invention.

[0033] [Optical film with adhesive backing]

[0034] An example of the optical film with adhesive sheet of this embodiment is shown below. Figure 1 . Figure 1 The optical film 11 with an adhesive sheet includes an adhesive sheet 1 and an optical film 2. The adhesive sheet 1 is attached to the optical film 2. The adhesive sheet 1 is a photocurable adhesive sheet formed from a photocurable composition. The adhesive sheet 1 contains a polymer A having constituent units derived from nitrogen-containing monomers.

[0035] The present inventors have found that one of the main causes of the deterioration of the image quality due to exposure to a high-temperature environment is that the adhesive sheet in the optical laminate and the adherend (adhesion target) in contact with the same easily peel off at high temperatures. In addition, the deterioration of the visual recognition due to the foaming of the monomer remaining in the adhesive sheet at high temperatures can also be a main cause. It is presumed that the photocurable adhesive sheet 1 containing the polymer A is suitable for increasing the polymerization rate at the time of formation, and the balance of the stress relaxation characteristics and the cohesive force thereof is suitable for suppressing the above-mentioned peeling at high temperatures. The polymer A is formed by the photopolymerization of the photocurable composition containing the nitrogen atom-containing monomer. When the nitrogen atom-containing monomer is present in the photopolymerization system, even in the case where the cumulative light amount of the irradiated light is small, for example, the tendency that the polymerization rate increases and the molecular weight of the polymer increases is observed. The fact that the stop reaction between the growing ends of the polymers is inhibited due to the increase in the viscosity of the polymerization system caused by the generation of hydrogen bonds, and the monomers easily remain at the ends of the growing chains can contribute to the above-mentioned tendency. In addition, it is presumed that the increase in the molecular weight contributes to the excellent balance of the stress relaxation characteristics and the cohesive force. Note that in the case where the amount of the photopolymerization initiator is increased for the purpose of increasing the polymerization rate, or the intensity of the light is increased to increase the cumulative light amount, the number of radicals generated at the same time increases, and thus the molecular weight does not easily increase. In addition, in the case of the heat-curable adhesive composition, since the monomers are dispersedly present in the solvent, hydrogen bonds are not easily generated, and chain transfer of radicals to the solvent also occurs in a large amount, and thus the above-mentioned effects due to the nitrogen atom-containing monomer are not observed.

[0036] <Adhesive sheet>

[0037] (Photocurable composition)

[0038] The adhesive sheet 1 is formed of a photocurable composition. The photocurable composition generally contains a monomer group and / or a partial polymer of the monomer group. By irradiating light to the photocurable composition, a polymer A is generated from the monomer group and / or the partial polymer, forming the adhesive sheet 1. The monomer group can contain a (meth)acrylic monomer. The content ratio of the (meth)acrylic component, i.e., the (meth)acrylic monomer and the partial polymer thereof, in the photocurable composition can be 50% by weight or more, 60% by weight or more, 70% by weight or more, and further, 80% by weight or more, in which case, an acrylic adhesive sheet in which a (meth)acrylic polymer is a main component can be formed. In other words, the polymer A can be a (meth)acrylic polymer. However, it should be noted that the photocurable composition is not limited to the above examples as long as a monomer containing a nitrogen atom is included. In the present specification, (meth)acrylic acid refers to acrylic acid and methacrylic acid. (Meth)acrylate refers to acrylate and methacrylate. In the present specification, a main component refers to a component having the largest content ratio. The content ratio of the main component is, for example, 50% by weight or more, and can be 60% by weight or more, 70% by weight or more, and further, 80% by weight or more.

[0039] Examples of the (meth)acrylic monomer are (meth)acrylic alkyl esters having an alkyl group having 1 to 20 carbon atoms in the side chain. The number of carbon atoms of the alkyl group can be 7 or less, 6 or less, 5 or less, and further, 4 or less. The alkyl group can be linear, or can have a branched chain. Examples of the (meth)acrylic alkyl ester are (meth)acrylic methyl ester, (meth)acrylic ethyl ester, (meth)acrylic propyl ester, (meth)acrylic isopropyl ester, (meth)acrylic n-butyl ester, (meth)acrylic sec-butyl ester, (meth)acrylic t-butyl ester, (meth)acrylic isobutyl ester, (meth)acrylic n-pentyl ester, (meth)acrylic isopentyl ester, (meth)acrylic n-hexyl ester, (meth)acrylic isohexyl ester, (meth)acrylic isoheptyl ester, (meth)acrylic 2-ethylhexyl ester, (meth)acrylic n-octyl ester, (meth)acrylic isooctyl ester, (meth)acrylic n-nonyl ester, (meth)acrylic isononyl ester, (meth)acrylic n-decyl ester, (meth)acrylic isodecyl ester, (meth)acrylic n-dodecyl ester ((meth)acrylic lauryl ester), (meth)acrylic n-tridecyl ester, (meth)acrylic n-tetradecyl ester, (meth)acrylic pentadecyl ester, (meth)acrylic cetyl ester, (meth)acrylic heptadecyl ester, and (meth)acrylic stearyl ester. The (meth)acrylic alkyl ester can be (meth)acrylic n-butyl ester.

[0040] The content ratio of the alkyl (meth)acrylate in the monomer group may be, for example, 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 85% by weight or more, 90% by weight or more, and further, 95% by weight or more. Note that, in calculating the content ratio, the weight of the partial polymer is converted into the weight of each monomer before polymerization.

[0041] The monomer group can include a carboxyl group-containing monomer. In this case, the polymer A further has a constitutional unit derived from the carboxyl group-containing monomer. By coexisting the carboxyl group-containing monomer with the nitrogen atom-containing monomer, the viscosity increase of the photopolymerization system is facilitated. The carboxyl group-containing monomer can be a (meth)acrylic monomer, in other words, the (meth)acrylic monomer can include the carboxyl group-containing monomer. Examples of the carboxyl group-containing monomer are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. The content ratio of the carboxyl group-containing monomer in the monomer group is, for example, 10% by weight or less, can be 9% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5.5% by weight or less, and further, 5% by weight or less. The lower limit of the content ratio is, for example, 0.1% by weight or more, can be 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, 2% by weight or more, 2.5% by weight or more, 3% by weight or more, 3.5% by weight or more, 4% by weight or more, and further, 4.5% by weight or more. The monomer group can not include the carboxyl group-containing monomer.

[0042] The monomer group can include a hydroxyl group-containing monomer. In this case, the polymer A further has a constitutional unit derived from the hydroxyl group-containing monomer. The hydroxyl group-containing monomer can be a (meth)acrylic monomer, in other words, the (meth)acrylic monomer can include the hydroxyl group-containing monomer. Examples of the hydroxyl group-containing monomer are 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, and (4-hydroxymethylcyclohexyl)methyl acrylate. The hydroxyl group-containing monomer is preferably 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate. The content ratio of the hydroxyl group-containing monomer in the monomer group is, for example, 10% by weight or less, can be 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.8% by weight or less, 0.5% by weight or less, 0.3% by weight or less, 0.2% by weight or less, and further, 0.1% by weight or less. The lower limit of the content ratio is, for example, 0.01% by weight or more, can be 0.03% by weight or more, and further, 0.05% by weight or more. The monomer group can not include the hydroxyl group-containing monomer.

[0043] The monomer group includes a nitrogen atom-containing monomer. The nitrogen atom-containing monomer refers to a monomer having at least one nitrogen atom in a molecule (1 molecule). Note that, in the present specification, a monomer having a hydroxyl group and a nitrogen atom in a molecule is classified as a nitrogen atom-containing monomer. A monomer having a carboxyl group and a nitrogen atom in a molecule is classified as a carboxyl group-containing monomer.

[0044] As the nitrogen atom-containing monomer, an N-vinyl cyclic amide, a (meth)acrylamide, or the like is preferable. Note that the nitrogen atom-containing monomer can be used alone or in combination of two or more.

[0045] The N-vinyl cyclic amide is preferably represented by the following formula (A).

[0046] [Chemical Formula 1]

[0047]

[0048] In formula (A), R 1 is a divalent organic group, preferably a divalent saturated hydrocarbon group or an unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (for example, an alkylene group having 3 to 5 carbon atoms, or the like). Note that formula (A) represents that N is directly bonded to R 1 by a single bond to form a ring structure.

[0049] As the N-vinyl cyclic amide represented by formula (A), N-vinyl-2-pyrrolidone (NVP), N-vinyl-2-piperidone, N-vinyl-2-caprolactam, N-vinyl-3-morpholinone, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinodione, or the like is preferable, more preferably N-vinyl-2-pyrrolidone, N-vinyl-2-caprolactam, and further preferably N-vinyl-2-pyrrolidone.

[0050] As the (meth)acrylamide, for example, (meth)acrylamide, N-alkyl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, or the like can be given. As the N-alkyl(meth)acrylamide, for example, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-n-butyl(meth)acrylamide, N-octylacrylamide, or the like can be given. The N-alkyl(meth)acrylamide also includes (meth)acrylamide having an amino group such as dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, dimethylaminopropyl(meth)acrylamide.

[0051] As the N,N-dialkyl(meth)acrylamide, for example, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N- diisopropyl(meth)acrylamide, N,N-di-n-butyl(meth)acrylamide, N,N-di-t-butyl(meth)acrylamide, and the like can be given.

[0052] The (meth)acrylamide also includes, for example, various N-hydroxyalkyl(meth)acrylamides. As the N-hydroxyalkyl(meth)acrylamide, for example, N-hydroxymethyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-(1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, N-methyl-N-2-hydroxyethyl(meth)acrylamide, and the like can be given.

[0053] The (meth)acrylamide also includes, for example, various N-alkoxyalkyl(meth)acrylamides. As the N-alkoxyalkyl(meth)acrylamide, for example, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, and the like can be given.

[0054] As the nitrogen atom-containing monomer other than the N-vinyl cyclic amide, (meth)acrylamide, for example, there can be mentioned aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, t-butylaminoethyl (meth)acrylate and the like amino group-containing monomers; acrylonitrile, methacrylonitrile and the like cyano group-containing monomers; (meth)acryloyl morpholine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinylisoxazole, vinylisoisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidine, (meth)acryloylpyrrole, (meth)acryloylpiperidine, N-methylvinylpyrrolidine and the like heterocyclic ring-containing monomers; N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide and the like maleimide-based monomers, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-laurylitaconimide, N-cyclohexylitaconimide and the like itaconimide-based monomers, N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxohexamethylenesuccinimide, N-(meth)acryloyl-8-oxooctamethylenesuccinimide and the like succinimide-based monomers, and the like imido group-containing monomers; 2-(meth)acryloyloxyethyl isocyanate and the like isocyanate group-containing monomers.

[0055] The content of the nitrogen atom-containing monomer in the monomer group can be, for example, 40% by weight or less, 35% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, 18% by weight or less, 15% by weight or less, 13% by weight or less, 12% by weight or less, and further, 11% by weight or less. The lower limit of the content can be, for example, 5% by weight or more, 7% by weight or more, 8% by weight or more, 9% by weight or more, and further, 10% by weight or more.

[0056] The monomer group preferably further contains a carboxyl group-containing monomer.

[0057] In the photocurable composition, each of the above-described monomers can be contained in the form of a partial polymer. The partial polymer can be any of a homopolymer and a copolymer. The photocurable composition can not contain a partial polymer.

[0058] The photocurable composition generally contains a photopolymerization initiator. Examples of the photopolymerization initiator are photoradical initiators that generate radicals by irradiation of light. In the photopolymerization initiator, the absorbance coefficient with respect to light having a wavelength of 340 nm is, for example, 0.1 L / (g-cm) or more, can be 0.5 L / (g-cm) or more, 1.0 L / (g-cm) or more, 3.0 L / (g-cm) or more, and further can be 5.0 L / (g-cm) or more. The upper limit of the absorbance coefficient is not particularly limited, and is, for example, 50 L / (g-cm) or less. The absorbance coefficient of the photopolymerization initiator is a value calculated from the absorbance of a 0.01 mg / mL methanol solution measured by a visible-ultraviolet spectrophotometer using a quartz cell having an optical path length of 1 cm.

[0059] Examples of the photopolymerization initiator are benzoin methyl ether, benzoin isopropyl ether, benzoin dimethyl ether, and the like benzoin ethers; substituted benzoin ethers such as benzoin methyl ether; substituted acetophenones such as 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and the like; a-hydroxyalkyl phenones such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2,2'-dihydroxy-2,2'-dimethyl-1,1'-[methylenebis(4,1-phenylene)]bis(propane-1-one), and the like; substituted a-alkanones such as 2-methyl-2-hydroxypropiophenone; aromatic sulfonyl chlorides such as 2-naphthalenesulfonyl chloride; photoactive oximes such as 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, benzoylbenzoic acid methyl ester, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyl diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, and the like; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-diethylthioxanthone, and the like; triazine compounds such as 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-piperonyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphthalen-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy-naphthalen-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, 2,4-trichloromethyl-(4'-methoxystyryl)-6-triazine, and the like; oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyl oxime)], O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene)hydroxylamine, and the like; phosphine compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, and the like; quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, ethyl anthraquinone, and the like; borate compounds; carbazole compounds; imidazole compounds; and titanocene compounds. The photocurable composition can contain one or two or more kinds of photopolymerization initiators. Note that the a-hydroxyalkyl phenones have a tendency to absorb a large amount of light having a wavelength of 340 ± 10 nm.

[0060] Another example of the photopolymerization initiator is a compound having a chemical structure represented by Formula (1) (hereinafter, referred to as Chemical Structure X) within the molecule.

[0061] [Chemical Formula 2]

[0062]

[0063] R in the above formula (1) 1 and R 2 each independently is a C1-C8 alkyl group; a hydrogen atom is substituted with -OH, a C1-C4 alkoxy group, -CN, -COOR 51 , -OOCR 52 or -NR 53 R 54 substituted C1-C4 alkyl group; a C3-C6 alkenyl group; or -CH2-C6H4-R 55 . R 1 and R 2 are optionally bonded to each other to form a C2-C9 alkylene group, or a C3-C6 oxyalkylene group, or an azole alkylene group. R 51 is a C1-C8 alkyl group. R 52 is a C1-C4 alkyl group. R 53 and R 54 each independently is a hydrogen atom, a C1-C12 alkyl group; a C2-C4 alkyl group in which a hydrogen atom is substituted with at least one selected from the group consisting of -OH, a C1-C4 alkoxy group, -CN and -COOR 59 ; a C3-C5 alkenyl group; or a cyclohexyl group. R 53 and R 54 may be a C3-C9 alkylene group bonded to each other and optionally interrupted by -O- or -N(R 60 )-. R 55 is a C1-C4 alkyl group. R 59 is a C1-C4 alkyl group. R 60 is a hydrogen atom, a C1-C4 alkyl group, an allyl group, a C1-C4 hydroxyalkyl group, -CH2CH2-COOR 61 or -CH2CH2CN. R 61 is a C1-C4 alkyl group.

[0064] X is -OR 56 , or -NR 57 R 58 . R 56 is a hydrogen atom, -SiR 62 3, a C1-C8 alkyl group, or a C3-C6 alkenyl group. R 57 and R 58 are a C1-C12 alkyl group; a C2-C4 alkyl group in which a hydrogen atom is substituted with at least one selected from the group consisting of -OH, a C1-C4 alkoxy group, -CN and -COOR 63 ; a C3-C5 alkenyl group; or a cyclohexyl group.57 and R 58 may be C3-C9 alkylene which can be bonded to each other and is optionally interrupted by -O- or -N(R 64 )-. R 62 is C1-C6 alkyl. R 63 is C1-C4 alkyl. R 64 is a hydrogen atom, C1-C4 alkyl, allyl, C1-C4 hydroxyalkyl, -CH2CH2-COOR 65 or -CH2CH2CN. R 65 is C1-C4 alkyl.

[0065] The chemical structure X can be bonded to a hydrogen atom or a substituted structure of a hydrogen atom via the carbon atom indicated by * in formula (1).

[0066] Each of the alkyl group, the alkoxy group, the alkenyl group, the alkylene group, the oxyalkylene group, the azaalkylene group and the hydroxyalkyl group described in the explanation of formula (1) can be either unbranched or branched. In addition, the description "Cn1-Cn2" (n1 and n2 are natural numbers) in the present specification, including the explanation of formula (1), means that the number of carbon atoms is in the range of n1 to n2.

[0067] R 1 and R 2 may each independently be C1-C8 alkyl or C3-C6 alkenyl, or C1-C8 alkyl. R 1 and R 2 may each independently be C1-C4 alkyl, or C1-C3 alkyl or C1-C2 alkyl. R 1 and R 2 may be methyl.

[0068] R 1 and R 2 may be the same.

[0069] X can be -OR 56 . R 56 may be a hydrogen atom or C1-C8 alkyl, or a hydrogen atom. In other words, X can be -OH.

[0070] R 1 , R 2 and X can take the above-mentioned preferable examples in any combination.

[0071] The chemical structure X can be the structure shown in the following formula (2). In the chemical structure X of formula (2), in the case where the substituted structure of the carbon atom indicated by * is bonded to a hydrogen atom, the substituted structure is bonded to -COCH2R 1 XR 2The group is in para position relative to the benzene ring of the chemical structure X.

[0072] [Chemical Formula 3]

[0073]

[0074] The photopolymerization initiator can be a compound having two or more chemical structures X in one molecule.

[0075] The photopolymerization initiator can be a compound represented by the following formula (3). The compound of formula (3) has two chemical structures X in one molecule. The two chemical structures X are bonded to each other at both ends of the molecule of the photopolymerization initiator through -A-, via the carbon atom of the phenylene group indicated by * above.

[0076] [Chemical Formula 4]

[0077]

[0078] R 1 and R 2 are groups that can be taken as R 1 and R 2 , respectively, and are independent of each other. 1 and R 2 . R 1 and / or R 2 may be the same as R 1 and / or R 2 . R 1 , R 2 , R 1 and R 2 may all be the same.

[0079] X' of formula (3) is a group that can be taken as X, independently of X of formula (1). X' and X can be the same.

[0080] A is -0-, -CYR 3 -, or -C(CH3)R 4 .

[0081] Y is a hydrogen atom, -Cl, -Br, -0-R 71 , -NR 72 R 73 , or -S-R 74 . R 3 is a hydrogen atom, a C1-C8 alkyl group, a C3-C6 alkenyl group, a benzyl group, -CH2-C6H4-R 75 , or a phenyl group. R 4C1-C6 alkyl or alkylene which is bonded together with the carbon atom of the phenylene group of the compound of formula (3).

[0082] R 71 hydrogen atom, -Si(R 76 )3, C1-C12 alkyl, C2-C18 acyl, -CO-NH-R 77 , C2-C20 hydroxyalkyl, C2-C20 methoxyalkyl, 3-R 78 -2-hydroxypropyl, 3-[1,3,3,3-tetramethyl-1 -[(trimethylsilyl)oxy]disiloxanyl]propyl, 2,3-dihydroxypropyl, or C2-C21 hydroxyalkyl interrupted by 1 to 9 oxygen atoms, or C3-C25 alkyl. R 72 and R 73 are each independently C1-C12 alkyl; C2-C4 alkyl substituted by at least one radical selected from the group consisting of -OH, C1-C4 alkoxy, -CN and -COOR 79 ; C3-C5 alkenyl; cyclohexyl; or C7-C9 phenylalkyl. R 72 and R 73 may be C3-C9 alkylene which is bonded to each other and optionally interrupted by -O- or -N(R 80 )-. R 74 is C1-C18 alkyl, hydroxyethyl, 2,3-dihydroxypropyl, cyclohexyl, benzyl, phenyl, C1-C12 alkylphenyl, -CH2-COOR 81 -CH2CH2-COOR 82 , or -CH(CH3)-COOR 83 . R 75 is C1-C4 alkyl. R 76 is C1-C6 alkyl. R 77 is C1-C12 alkyl. R 78 is C1-C18 alkoxy. R 79 is C1-C4 alkyl. R 80 is hydrogen atom, C1-C4 alkyl, allyl, benzyl, C1-C4 hydroxyalkyl, -CH2CH2-COOR 84 , or -CH2CH2CN. R 81 , R 82 and R 83 are each independently C1-C18 alkyl. R 84 is C1-C4 alkyl.

[0083] The alkyl moiety in the alkyl group, the alkenyl group, the acyl group, the hydroxyalkyl group, the methoxyalkyl group, the alkoxy group, the phenylalkyl group in the explanation of the formula (3) can be either unbranched or branched.

[0084] R of the formula (3) 1 , R 2 , R 1 , and R 2 are the same as the preferable examples of R 1 and R 2 in the explanation of the formula (1) above. The preferable examples of X' of the formula (3) are the same as the preferable examples of X in the explanation of the formula (1) above. A can be -CYR 3 -. Y can be a hydrogen atom. R 3 can be a hydrogen atom. A can be -CYR 3 -, and Y and R 3 are both hydrogen atoms. In other words, A can be -CH2-.

[0085] R of the formula (3) 1 , R 2 , R 1 , R 2 , X, X', and A can take the preferable examples described above in any combination.

[0086] The photopolymerization initiator can be a compound represented by the following formula (4). The compound of the formula (4) is one of the compounds of the formula (3).

[0087] [Chemical Formula 5]

[0088]

[0089] Specific examples of the photopolymerization initiator are shown in the following formulas (5) to (9). The photopolymerization initiator can be a compound represented by at least one of the chemical formulas selected from the group consisting of the formulas (5) to (9), can be a compound represented by at least one of the chemical formulas selected from the group consisting of the formulas (5) to (8), can be a compound represented by at least one of the chemical formulas selected from the group consisting of the formulas (5) to (7), and can be a compound represented by the formula (5). Note that the compound of the formula (8) is derived from a vinyl compound having a chemical structure X in the side chain. More specifically, it is an oligomer of the vinyl compound.

[0090] [Chemical Formula 6]

[0091]

[0092] [Chemical Formula 7]

[0093]

[0094] [Chemical Formula 8]

[0095]

[0096] [Chemical Formula 9]

[0097]

[0098] [Chemical Formula 10]

[0099]

[0100] The photopolymerization initiators represented by Formulas (5) to (9) are commercially available as Omnirad 127, Esacure KIP 160, Esacure one, Esacure KIP 150, and Omnirad 1173 (all manufactured by IGM Resins), respectively. The photopolymerization initiator can be at least one selected from them.

[0101] Examples of the specific photopolymerization initiator are 1-hydroxycyclohexyl-phenyl ketone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)2-methylpropane-1-one. Of these, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)2-methylpropane-1-one is preferred. Each of the above photopolymerization initiators is commercially available as Omnirad 184, Omnirad 819, and Omnirad 127 (all manufactured by IGM Resins), respectively.

[0102] The content of the photopolymerization initiator in the photocurable composition is, for example, 20 parts by weight or less, can be 10 parts by weight or less, 5.0 parts by weight or less, 3.0 parts by weight or less, 1.0 parts by weight or less, 0.5 parts by weight or less, 0.3 parts by weight or less, 0.25 parts by weight or less, and further can be 0.2 parts by weight or less, relative to 100 parts by weight of the total of the monomer group and the partial polymer thereof. The lower limit of the content of the photopolymerization initiator is, for example, 0.01 parts by weight or more, can be 0.03 parts by weight or more, 0.05 parts by weight or more, and further can be 0.06 parts by weight or more, relative to 100 parts by weight of the total of the monomer group and the partial polymer thereof.

[0103] The photocurable composition can contain a crosslinking agent. Examples of the crosslinking agent are polyfunctional monomers having two or more polymerizable functional groups in one molecule. The polyfunctional monomer can be a (meth)acrylic monomer. Examples of the polyfunctional monomer are monomers having two or more C=C bonds in one molecule, and monomers having one or more C=C bonds, and one or more polymerizable functional groups such as an epoxy group, an aziridinyl group, an oxazolinyl group, a hydrazine group, a methylol group, and the like in one molecule. The polyfunctional monomer is preferably a monomer having two or more C=C bonds in one molecule.

[0104] Examples of the polyfunctional monomer are polyfunctional acrylates (ester compounds of (poly)ethylene glycol, (poly)propylene glycol, neopentyl glycol, pentaerythritol, dipentaerythritol, 1,2-ethanediol, 1,6-hexanediol, 1,9-nonanediol, 1,12-dodecanediol, trimethylolpropane, tetramethylolmethane, and the like with (meth)acrylic acid), allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, hexyl di(meth)acrylate. The polyfunctional monomer is preferably a polyfunctional acrylate, more preferably 1,9-nonanediol diacrylate, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate.

[0105] The blending amount of the crosslinking agent varies depending on the molecular weight, the number of functional groups, and the like, and is, for example, 5 parts by weight or less, can be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, 0.5 parts by weight or less, 0.3 parts by weight or less, 0.2 parts by weight or less, and further can be 0.15 parts by weight or less, relative to 100 parts by weight of the total of the monomer component and the partial polymer thereof. The lower limit of the blending amount is, for example, 0.01 parts by weight or more, can be 0.03 parts by weight or more, 0.05 parts by weight or more, 0.06 parts by weight or more, 0.08 parts by weight or more, and further can be 0.1 parts by weight or more. The photocurable composition can not contain the crosslinking agent.

[0106] The photocurable composition can contain an additive other than the above. Examples of the additive are a chain transfer agent, a silane coupling agent, a viscosity modifier, an adhesion promoter, a plasticizer, a softener, an anti-aging agent, a filler, a colorant, an antioxidant, a surfactant, an antistatic agent, and an ultraviolet absorber. The photocurable composition can not contain the additive.

[0107] Examples of the silane coupling agent are epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane, and the like; (meth)acryl group-containing silane coupling agents such as 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, and the like; and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane.

[0108] The silane coupling agent can also be an oligomer-type silane coupling agent. The oligomer-type silane coupling agent generally has a plurality of alkoxysilyl groups in one molecule. Specific examples of the oligomer-type silane coupling agent are products of Shin-Etsu Silicones Co., Ltd. under the trade names "X-41-1053", "X-41-1056", "X-41-1059A", "X-41-1805", "X-41-1810", "X-41-1818", "X-40-2651", and "X-24-9591F". The oligomer-type silane coupling agent can have a reactive functional group. Examples of the reactive functional group are an epoxy group, a mercapto group, an anhydride group, and an amino group. Among them, an oligomer-type silane coupling agent having an epoxy group is preferable, and an oligomer-type silane coupling agent having a plurality of epoxy groups in one molecule is more preferable. Examples of the oligomer-type silane coupling agent having an epoxy group are the above-mentioned "X-41-1053", "X-41-1056", and "X-41-1059A". Examples of the oligomer-type silane coupling agent having a mercapto group are the above-mentioned "X-41-1805", "X-41-1810", and "X-41-1818". An example of the oligomer-type silane coupling agent having an anhydride group is the above-mentioned "X-24-9591F". An example of the oligomer-type silane coupling agent having an amino group is the above-mentioned "X-40-2651".

[0109] The silane coupling agent can be an acetoacetyl group-containing silane coupling agent (for example, "A-100" manufactured by Soken Chemical Co., Ltd.).

[0110] In the case where the photocurable composition contains a silane coupling agent, the blending amount thereof is, for example, 5 parts by weight or less, can be 3 parts by weight or less, 1 part by weight or less, 0.5 parts by weight or less, 0.2 parts by weight or less, 0.1 parts by weight or less, and further can be 0.05 parts by weight or less, with respect to 100 parts by weight of the total of the monomer group and the partially polymerized product thereof. The photocurable composition can also not contain a silane coupling agent.

[0111] The viscosity of the photocurable composition is preferably 5 to 100 poise. The photocurable composition having a viscosity within the above range is particularly suitable for the formation of the adhesive sheet 1.

[0112] The content of the solvent in the photocurable composition is, for example, 5% by weight or less, can be 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, and further can be 0.5% by weight or less. The photocurable composition can substantially not contain the solvent. By substantially not containing the solvent is meant that a solvent or the like from an additive or the like can be contained at a content of, for example, 0.1% by weight or less, preferably 0.05% by weight or less, and more preferably 0.01% by weight or less. In addition, the content of the solvent in the adhesive sheet 1 can be within the above range. The adhesive sheet 1 can also substantially not contain the solvent.

[0113] (Method for producing adhesive sheet)

[0114] The adhesive sheet 1 can be formed, for example, by irradiating the first laminate 20 including the substrate sheet 21, the coating layer 22 containing the photocurable composition, and the release liner 23 in this order with light 24 (refer to Figure 2 ). The coating layer 22 is cured by the irradiation with the light 24, and becomes the adhesive sheet 1. Typically, the irradiation with the light 24 is performed from one side of the substrate sheet 21. At this time, the light 24 passes through the substrate sheet 21 and reaches the coating layer 22, and the coating layer 22 is cured. The irradiation with the light 24 can also be performed from one side of the release liner 23, and can also be performed from both sides of the release liner 23 and the substrate sheet 21.

[0115] The adhesive sheet 1 formed is sandwiched by the substrate sheet 21 and the release liner 23, and constitutes a part of the second laminate 27 until the release liner 23 is peeled. By peeling the release liner 23 from the second laminate 27, the third laminate 25 including the substrate sheet 21 and the adhesive sheet 1 can be obtained. In the third laminate 25, the surface of the adhesive sheet 1 is exposed to the outside. To the surface of the adhesive sheet 1 exposed, an optical film can be laminated directly or via another layer.

[0116] The light 24 is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light can include light having a wavelength in the same region as the absorption wavelength of the photopolymerization initiator included in the photocurable composition. The light obtained by cutting off short-wavelength light having a wavelength of 300 nm or less with a light filter or the like can be irradiated, and the cutting off of the short-wavelength light is suitable for inhibiting the deterioration of the base sheet 21 and / or the release liner 23 caused by the light 24. The light source 28 of the light 24 is, for example, a light irradiation device provided with an ultraviolet irradiation lamp. Examples of the ultraviolet irradiation lamp include an ultraviolet LED, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a xenon lamp, a microwave-excited mercury lamp, a black light, a chemical lamp, a germicidal lamp, a low-pressure discharge mercury lamp, and an excimer laser. Two or more kinds of ultraviolet irradiation lamps can be combined. According to the ultraviolet LED, the bandwidth of the irradiated ultraviolet light can be narrowed compared to the case where another light source is used.

[0117] The light source 28 can be an LED. The LED has a tendency that not only the illuminance can be adjusted more easily but also the light source has a longer life compared to a black light source. From the viewpoint of reducing the environmental burden, the LED can be said to be more excellent compared to a black light source using mercury. In the case where an ultraviolet LED is used as the light source, an LED having a peak wavelength of 325 to 350 nm can be selected. According to the research by the present inventors and the like, the use of the LED having a peak wavelength of 325 to 350 nm can contribute to at least one selected from the group consisting of an increase in the polymerization rate of the monomer group in the adhesive sheet 1, an increase in the molecular weight of the polymer A, and a reduction in the residual amount of the photopolymerization initiator, for example, compared to the case where a black light source is used. Further, the LED emitting the light 14 having a peak wavelength of 325 to 350 nm has a tendency that the LED is less likely to heat and the temperature of the coated layer 22 is easily controlled compared to an LED emitting light having a peak wavelength of about 365 nm. Note that, according to the knowledge of the present inventors and the like, there has been no report on an example of manufacturing an adhesive sheet using an LED emitting light having a peak wavelength of 325 to 350 nm so far.

[0118] As the LED having a peak wavelength of 325 to 350 nm, an LED having a peak wavelength of 340 ± 10 nm (hereinafter, referred to as LED340) can be selected.

[0119] When considering the peak wavelength of light 24, the peak wavelength of light 24 irradiating the first layer stack 20 (specifically, coating layer 22) can be 325 nm to 350 nm. Preferably, the peak wavelength of light 24 is 340 ± 10 nm (330 nm to 350 nm), but it can be 340 ± 5 nm (335 nm to 345 nm), 340 ± 2 nm (338 nm to 342 nm), or 340 nm. The peak wavelength refers to the wavelength at which the intensity reaches its maximum value in the spectrum showing the relationship between the wavelength and intensity of light 24. Light 24 may further have peak wavelengths in other wavelength regions besides 325 nm to 350 nm, but it is preferable not to.

[0120] The illuminance of light 24 illuminating the first laminate 20 (specifically, coating layer 22) is, for example, 2.0~30 mW / cm². 2 The illuminance can be 2.5 mW / cm². 2 Above, 3.0mW / cm 2 Above, 3.5mW / cm 2 Above, 4.0mW / cm 2 Above, 5.0mW / cm 2 Above, 6.0mW / cm 2 Above, 7.0mW / cm 2 Above, 8.0mW / cm 2 Above, 9.0mW / cm 2 The above, and thus can be 10mW / cm 2 The above. The upper limit for illuminance is, for example, 25 mW / cm². 2 The following can be 20mW / cm 2 The following, and further, can be 15mW / cm 2 the following.

[0121] The duration of illumination 24 on the first layer stack 20 (specifically, the coating layer 22) is, for example, from 10 seconds to 1000 seconds, and can be 60 seconds or more, 100 seconds or more, 150 seconds or more, 200 seconds or more, 250 seconds or more, and further, 300 seconds or more. The upper limit of the duration is, for example, less than 800 seconds, and can be less than 600 seconds, 500 seconds or less, 400 seconds or less, 350 seconds or less, 300 seconds or less, and further, less than 250 seconds. The illumination of light 24 can be continuous or intermittent.

[0122] The cumulative light intensity of light 24 relative to the first layer stack 20 (specifically, coating layer 22) is, for example, 25 mJ / cm. 2 The above can be 100mJ / cm 2 Above, 250mJ / cm 2above, 500 mJ / cm 2 above, 750 mJ / cm 2 above, 850 mJ / cm 2 above, 1000 mJ / cm 2 above, 1250 mJ / cm 2 above, and further, 1500 mJ / cm 2 above. The upper limit of the cumulative light amount is not particularly limited, and is, for example, 3000 mJ / cm 2 below, 2500 mJ / cm 2 below, 2000 mJ / cm 2 below, 1750 mJ / cm 2 below, 1500 mJ / cm 2 below, 1250 mJ / cm 2 below, and further, 1000 mJ / cm 2 below. The adhesive sheet 1 is suitable for formation at a low cumulative light amount, and thus, the productivity of the optical film 11 with the adhesive sheet is excellent.

[0123] Examples of the base material of the release liner 23 (hereinafter, "liner base material") are resin films. Examples of the resin that can be contained in the liner base material are polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth)acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

[0124] The release liner 23 can have a layer other than the liner base material. The release liner 23 can have a release layer. The release liner 23, for example, has a liner base material and a release layer formed on one face of the liner base material. This release liner 23 can be used in such a manner that the release layer is on the side of the coating layer 22. Typically, the release layer is a cured layer of a release agent composition containing a release agent. The release agent can be various release agents such as silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, fatty acid amide-based release agents, and silica powder.

[0125] The release liner 23 can be in a single sheet shape or in a long strip shape.

[0126] Examples of the base material sheet 21 are resin films. Examples of the resin contained in the base material sheet 21 are the same as examples of the resin that can be contained in the liner base material.

[0127] The thickness of the base material sheet 21 is, for example, 10 to 200 μm, and can be 25 to 150 μm.

[0128] The base sheet 21 can have a release layer on the side of the coated layer 22. Examples of the release layer that the base sheet 21 can have are the same as examples of the release layer that the release liner 23 can have. The release liner 23 and the base sheet 21 can both have a release layer.

[0129] The base sheet 21 can be generally selected to have a greater release force from the adhesive sheet 1 than the release liner 23.

[0130] The base sheet 21 can be in a single sheet shape or in a long strip shape.

[0131] The first laminate 20 can be formed, for example, by forming the coated layer 22 on the base sheet 21 (or the release liner 23) and disposing the release liner 23 (or the base sheet 21) on the formed coated layer 22. Alternatively, the first laminate 20 can be formed by coating in such a manner that the photocurable composition flows into a space between the base sheet 21 and the release liner 23 held at a given interval with the main surfaces of the base sheet 21 and the release liner 23 facing each other.

[0132] The formation of the coated layer 22 can employ various coating methods such as roll coating, roll kiss coating, gravure coating, reverse coating, roll brushing, spraying, dip roll coating, bar coating, blade coating, air knife coating, curtain coating, lip coating, die coating, and the like.

[0133] The thickness of the coated layer 22 can be adjusted according to the thickness of the target adhesive sheet 1, for example, to be 5 to 100 μm, to be 5 to 50 μm, to be 5 to 25 μm, and further to be 5 to 20 μm.

[0134] The first laminate 20 can include a long strip-shaped base sheet 21, a long strip-shaped coated layer 22, and a long strip-shaped release liner 23, in other words, can be in a long strip shape. The long strip-shaped first laminate 20 can be obtained, for example, by forming the coated layer 22 between the base sheet 21 and the release liner 23 while continuously discharging the base sheet 21 and the release liner 23 from a roll body.

[0135] The Mw of the polymer A included in the adhesive sheet 1 is, for example, 600,000 or more, 650,000 or more, 700,000 or more, 750,000 or more, 800,000 or more, 850,000 or more, 900,000 or more, 950,000 or more, 1,000,000 or more, 1,100,000 or more, 1,200,000 or more, 1,300,000 or more, and further 1,400,000 or more. The upper limit of the Mw is not particularly limited, and is, for example, 3,000,000 or less. The Mw of the polymer A can be found from a value calculated by GPC (gel permeation chromatography) measurement and polystyrene conversion.

[0136] The polymerization rate of the monomer group in the adhesive sheet 1 can be 97.5% or more, 98% or more, and further 98.5% or more. The upper limit of the polymerization rate is, for example, 99.99% or less. A high polymerization rate can contribute to, for example, the suppression of odor of the adhesive sheet 1.

[0137] In the adhesive sheet 1, the molecular weight of the polymer and the polymerization rate of the monomer group can be increased at the same time. The weight average molecular weight (Mw) of the polymer contained in the adhesive sheet 1 can be 600,000 or more, and the polymerization rate of the monomer group in the adhesive sheet 1 can be 98% or more. The Mw and the polymerization rate can be in the above numerical ranges, respectively.

[0138] The gel fraction of the adhesive sheet 1 is, for example, 55% or more, can be 60% or more, 65% or more, 70% or more, 75% or more, 78% or more, 80% or more, more than 80%, 81% or more, 82% or more, 83% or more, 84% or more, and further can be 85% or more. The upper limit of the gel fraction can be 95% or less, 94% or less, 93% or less, 92% or less, 91% or less, 90% or less, and further can be 89% or less.

[0139] The gel fraction of the adhesive sheet 1 can be evaluated as follows. About 0.1 g of a test piece is taken from the adhesive sheet 1, wrapped with a polytetrafluoroethylene porous sheet (average pore diameter 0.2 μm, trade name "NTF1122", manufactured by Nitto Electric Industrial Co., Ltd.), and bundled with a kite string to obtain a measurement sample. Next, the weight of the obtained measurement sample (weight before immersion C) is measured. The weight before immersion C is the total weight of the test piece, the polytetrafluoroethylene porous sheet, and the kite string. Separately, the bag weight B, which is the total weight of the polytetrafluoroethylene porous sheet and the kite string, is measured in advance. Next, the measurement sample is housed in a container with a volume of 50 mL filled with ethyl acetate, and left to stand at 23°C for 7 days. After the standing, the measurement sample is taken out of the container and transferred to an aluminum cup, and the ethyl acetate is removed by drying at 130°C for 2 hours using a drier. The weight of the measurement sample after the drying (weight after immersion A) is measured. The value calculated from the following formula is determined as the gel fraction of the adhesive sheet 1.

[0140] Gel fraction (%) = (A - B) / (C - B) x 100

[0141] The thickness of the adhesive sheet 1 is, for example, 2 to 70 μm. The thickness can be 50 μm or less, 40 μm or less, 30 μm or less, 25 μm or less, and further, 20 μm or less. The lower limit of the thickness can be 5 μm or more, 10 μm or more, and further, 15 μm or more. A thin adhesive sheet 1, for example, an adhesive sheet 1 having a thickness of 30 μm or less, is easily affected by polymerization inhibition caused by oxygen in the environment when formed by photocuring. On the other hand, the adhesive sheet 1 is suitable for formation under a low cumulative light amount, in other words, for formation by photocuring for a short time. Therefore, the effects caused by polymerization inhibition can be suppressed even in the case of thinness. In addition, the adhesive sheet 1 is suitable for suppressing bubbling in a high-temperature environment and peeling from an adherend even when formed to have a thickness of, for example, 30 μm or less. The adherend is, for example, a glass substrate.

[0142] <Optical film>

[0143] Examples of the optical film 2 are a polarizing film, a phase difference film, and a laminated film including a polarizing film and / or a phase difference film. Among them, the optical film 2 is not limited to the above examples. The optical film 2 can also include a film made of glass.

[0144] The optical film 2 is a polarizing film, and the adhesive sheet 1 can be in contact with the polarizing film. Among optical films, a polarizing film has a tendency that the dimensional change caused by heat is large. The dimensional change of the polarizing film can become a major cause of peeling from the adhesive film. Therefore, the present application is particularly advantageous in the case where the optical laminate further has a polarizing film.

[0145] The polarizing film includes a polarizer. Typically, the polarizing film includes a polarizer and a protective film (transparent protective film). The protective film is disposed, for example, in contact with a main surface (a surface having the widest area) of the polarizer. The polarizer can be disposed between two protective films. The protective film can be disposed on at least one side of the polarizer.

[0146] As the polarizer, there is no particular limitation, and examples that can be given are: a polarizer obtained by adsorbing a dichroic substance such as iodine or a dichroic dye to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer-based partially saponified film, and the like, and performing unidirectional stretching; a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol, a dehydrochlorinated product of polyvinyl chloride, and the like. Typically, the polarizer is formed of a polyvinyl alcohol-based film (a polyvinyl alcohol-based film including an ethylene-vinyl acetate copolymer-based partially saponified film) and a dichroic substance such as iodine.

[0147] The thickness of the polarizer is not particularly limited, and is, for example, 80 μm or less, and can be 50 μm or less, 30 μm or less, 25 μm or less, and further can be 20 μm or less. The lower limit of the thickness of the polarizer is not particularly limited, and is, for example, 1 μm or more, and can be 5 μm or more, 10 μm or more, and further can be 15 μm or more. The dimensional change of a thin polarizer (for example, 20 μm or less in thickness) is suppressed, and this can contribute to the improvement of the durability of the optical laminate, particularly the durability at high temperatures.

[0148] As the material of the protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like can be used. As specific examples of such a thermoplastic resin, cellulose resins such as cellulose triacetate, polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof can be given. The material of the protective film can be a thermosetting resin such as a (meth)acrylic resin, a urethane resin, an acryl urethane resin, an epoxy resin, a silicone resin, or an ultraviolet-curable resin. In the case where the polarizing film has two protective films, the materials of the two protective films can be the same or different from each other. For example, a protective film formed of a thermoplastic resin can be attached to one main surface of the polarizer via an adhesive, and a protective film formed of a thermosetting resin or an ultraviolet-curable resin can be attached to the other main surface of the polarizer. The protective film can contain one or more arbitrary additives. As the additives, for example, ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloration-preventing agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like can be given.

[0149] The thickness of the protective film can be appropriately determined, and is generally about 5 to 200 μm from the viewpoints of strength, handling properties, film thickness, and the like.

[0150] The polarizer and the protective film are generally closely attached to each other via a water-based adhesive or the like. As the water-based adhesive, isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latexes, water-based polyurethanes, water-based polyesters, and the like can be given. As other adhesives other than the above-described adhesives, ultraviolet-curable adhesives, electron beam-curable adhesives, and the like can be given. Electron beam-curable adhesives for polarizing films exhibit suitable adhesiveness to various protective films. The adhesive can also contain a metal compound filler.

[0151] In the polarizing film, a phase difference film or the like can be formed on the polarizer instead of the protective film. Another protective film can be provided on the protective film, a phase difference film or the like can be provided.

[0152] As for the protective film, a hard coat layer can be provided on a surface opposite to the surface bonded to the polarizer, and the protective film can be subjected to a treatment for the purpose of antireflection, anti-sticking, diffusion, antiglare, and the like.

[0153] The polarizing film can be a circularly polarizing film.

[0154] The thickness of the polarizing film is, for example, 500 μm or less, can be 300 μm or less, 200 μm or less, 100 μm or less, and further can be 60 μm or less. The lower limit of the thickness is, for example, 10 μm or more, can be 25 μm or more, and further can be 40 μm or more.

[0155] The phase difference film is a film having birefringence in the in-plane direction and / or the thickness direction. The phase difference film is, for example, a resin film stretched, a film obtained by orienting and fixing a liquid crystal material.

[0156] The phase difference film can be a λ / 4 wave plate, a λ / 2 wave plate, a phase difference film for antireflection (for example, refer to paragraphs 0221, 0222, and 0228 of Japanese Patent Application Publication No. 2012-133303), a phase difference film for viewing angle compensation (for example, refer to paragraphs 0225 and 0226 of Japanese Patent Application Publication No. 2012-133303), a tilt orientation phase difference film for viewing angle compensation (for example, refer to paragraph 0227 of Japanese Patent Application Publication No. 2012-13303). The phase difference film is not limited to the above examples as long as it has birefringence in the in-plane direction and / or the thickness direction. The phase difference value, the arrangement angle, the three-dimensional birefringence, whether it is a single layer or a multilayer, and the like of the phase difference film are not limited. The phase difference film can use a publicly known film.

[0157] The thickness of the optical film 2 is, for example, 1 to 200 μm.

[0158] The optical film 2 can be a single layer or a laminated film composed of two or more layers. In the case where the optical film 2 is a laminated film, the bonding of the layers can use the adhesive sheet 1.

[0159] The optical film 11 with an adhesive sheet can have other layers in addition to the adhesive sheet 1 and the optical film 2. Other layers can be arranged between the adhesive sheet 1 and the optical film 2, but it is preferable that the adhesive sheet 1 and the optical film 2 are in contact.

[0160] The optical film 11 with an adhesive sheet can be used, for example, for an optical laminate, an image display device. The use of the optical film 11 with an adhesive sheet is not limited to the above examples.

[0161] [Optical Laminate]

[0162] An example of the optical laminate of the present embodiment is shown in Figure 3 . Figure 3The optical laminate 30A includes the optical film 11 with adhesive sheet according to this embodiment. The optical laminate 30A has a laminated structure in which release liner 3, adhesive sheet 1 and optical film 2 are sequentially stacked. The optical laminate 30A can be used in the form of optical film 11 with adhesive sheet formed by peeling off release liner 3.

[0163] The release liner 3 is typically a resin film. Examples of resins constituting the release liner 3 include polyesters such as polyethylene terephthalate (PET), polyolefins such as polyethylene and polypropylene, polycarbonate, acrylics, polystyrene, polyamide, and polyimide. The side of the release liner 3 that is in contact with the adhesive sheet 1 may also be subjected to a release treatment. The release treatment may be, for example, a treatment using an organosilicon compound. However, the release liner 3 is not limited to the above examples. The release liner 3 can be released when using the optical laminate 30A, for example, when it is adhered to the image forming layer.

[0164] Another example of the optical laminate of this embodiment is shown below. Figure 4 . Figure 4 The optical laminate 30B includes the optical film 11 with an adhesive sheet as described in this embodiment. The optical laminate 30B has a laminated structure in which a release liner 3, an adhesive sheet 4, a retardation film 2B, an adhesive sheet 1, and a polarizing film 2A are sequentially stacked. The optical laminate 30B can be used by peeling off the release liner 3 and then attaching it to, for example, an image forming layer.

[0165] Adhesive sheet 4 can be a known adhesive sheet. Adhesive sheet 1 can be used for adhesive sheet 4.

[0166] Another example of the optical laminate of this embodiment is shown below. Figure 5 . Figure 5 The optical laminate 30C includes the optical film 11 with an adhesive sheet as described in this embodiment. The optical laminate 30C has a laminated structure in which a release liner 3, an adhesive sheet 4, a retardation film 2B, an adhesive sheet 1, a polarizing film 2A, and a protective film 5 are sequentially stacked. The optical laminate 30C can be used by peeling off the release liner 3 and then attaching it to, for example, an image forming layer.

[0167] The protective film 5 protects the outermost optical film 2 (polarizer 2A) during the flow and storage of the optical laminate 30C, and also when the optical laminate 30C is introduced into the image display device. Furthermore, when introduced into the image display device, the protective film 5 can function as a window to the external space. The protective film 5 is typically a resin film. The resin constituting the protective film 5 is, for example, polyester such as PET, polyolefins such as polyethylene and polypropylene, acrylics, cycloolefins, polyimide, and polyamide, preferably polyester. However, the protective film 5 is not limited to the above examples. The protective film 5 can be a glass film or a laminate containing a glass film. Surface treatments such as anti-glare, anti-reflection, and antistatic treatments can be applied to the protective film 5.

[0168] The protective film 5 can be bonded to the optical film 2 using any adhesive. It can also be bonded using the adhesive sheet 1.

[0169] The optical laminate of this embodiment can include any layer other than the layers described above. The optical laminate of this embodiment can have any configuration as long as it includes the optical film 11 with the adhesive sheet.

[0170] The optical laminate of this embodiment can be distributed and stored, for example, in the form of a wound body formed by winding a strip of optical laminate, or in the form of a single sheet of optical laminate.

[0171] Typically, the optical laminate of this embodiment can be used in an image display device. The image display device is, for example, an EL display such as a liquid crystal display, an organic EL display, or an inorganic EL display.

[0172] [Image display device]

[0173] An example of the image display device of this embodiment is shown below. Figure 6 . Figure 6 The image display device 31 has a stacked structure in which a substrate 7, an image forming layer (e.g., an organic EL layer or a liquid crystal layer) 6, an adhesive sheet 4, a phase retardation film 2B, an adhesive sheet 1, a polarizing film 2A, and a protective film 5 are sequentially stacked. The image display device 31 possesses Figure 1 Optical film 11 with adhesive sheet, and Figures 3-5 The optical laminates 30A, 30B, and 30C (except for the release liner 3) are used. The substrate 7 and the image forming layer 6 may have the same configuration as those of the substrate and image forming layer in a known image display device.

[0174] Figure 6 The image display device 31 can be an organic EL display or a liquid crystal display. However, the image display device 31 is not limited to this example. The image display device 31 can also be an electroluminescent (EL) display, a plasma display (PD), a field emission display (FED), etc. The image display device 31 can be used for home appliances, automotive applications, public information displays (PIDs), etc.

[0175] The image display device 31 can have any configuration as long as it has an optical film 11 with an adhesive sheet and / or an optical laminate of this embodiment.

[0176] Example

[0177] The present invention will now be described in more detail through embodiments. The present invention is not limited to the embodiments shown below.

[0178] [Production of photocurable composition]

[0179] (Monomer slurry Al)

[0180] N-butyl acrylate (BA) 99.0 parts by weight and 4-hydroxybutyl acrylate (HBA) 1.0 part by weight were put into a four-necked flask together with Omnirad 184 (manufactured by IGM Resin Co., Ltd.) 0.16 part by weight and Omnirad 819 (manufactured by IGM Resin Co., Ltd.) 0.04 part by weight as photopolymerization initiators. Next, the liquid in the flask was irradiated with ultraviolet rays under a nitrogen atmosphere, whereby a monomer slurry Al in which the monomers were partially photopolymerized was obtained. The irradiation with ultraviolet rays was performed until the viscosity (measuring conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) of the liquid in the flask reached 20 Pa-s.

[0181] (Monomer slurries A2 to A4)

[0182] The monomers and the photopolymerization initiators were changed as shown in Table 1, and monomer slurries A2 to A4 were prepared by the same method as monomer slurry Al, except for this.

[0183]

[0184] The abbreviations in Table 1 are as described below.

[0185] BA: N-butyl acrylate

[0186] HBA: 4-hydroxybutyl acrylate

[0187] AA: Acrylic acid

[0188] Omnirad 184: 1-hydroxycyclohexyl-phenyl ketone (Omnirad 184, manufactured by IGM Resin Co., Ltd.)

[0189] Omnirad 819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819, manufactured by IGM Resin Co., Ltd.)

[0190] Omnirad 127: 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl) 2-methylpropane-1-one (Omnirad 127, manufactured by IGM Resin Co., Ltd.)

[0191] (Photocurable compositions C1 to C10)

[0192] Next, the monomer slurries, the monomers, the crosslinking agents, and the silane coupling agents were mixed in the compositions shown in Table 2 below to obtain photocurable compositions C1 to C10.

[0193]

[0194] The abbreviations in Table 2 are described below.

[0195] AA: acrylic acid

[0196] NVP: N-vinyl-2-pyrrolidone

[0197] NDDA: 1,9-nonanediol diacrylate

[0198] KBM403: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicones, trade name "KBM-403")

[0199] X-41-1056: oligomer-type silane coupling agent containing an epoxy group (manufactured by Shin-Etsu Silicones, trade name "X-41-1056")

[0200] The final composition of the monomers contained in each photocurable composition is shown in Table 3 below.

[0201]

[0202] [Production of Adhesive Sheet]

[0203] [Example 1]

[0204] (Production of Release Liner)

[0205] A silicone-based mold release agent composition was obtained by mixing 30 parts by weight of an addition reaction-curable silicone (LTC761 containing a hexenyl group-containing polyorganosiloxane, 30% by weight in toluene, manufactured by Toray Dow Corning), 0.9 parts by weight of a release control agent (BY24-850 containing an unreactive silicone resin, manufactured by Toray Dow Corning), and 2 parts by weight of a curing catalyst (SRX212 containing a platinum catalyst, manufactured by Toray Dow Corning), and a toluene / hexane mixed solvent (volume ratio 1:1) as a dilution solvent. The concentration of the silicone solid component in the mold release agent composition was 1.0% by weight. Next, the mold release agent composition was applied to one side of a base substrate (Lumirror XD500P as a polyester film, thickness 75 μm) using a wire bar, and heated at 130°C for 1 minute to produce a release liner having a mold release layer (thickness 60 nm) on one side.

[0206] (Production of Adhesive Sheet)

[0207] A monomer slurry C1 was applied to one side of a base sheet (PET film, manufactured by Mitsubishi Resin, MRF38) using an applicator to form a coated layer (thickness 20 μm). Next, a release liner was arranged on the formed coated layer to obtain a first laminate. The release liner was arranged so that the release layer was in contact with the coated layer. Next, light was irradiated from the side of the base sheet of the first laminate under conditions of illuminance 8.8 mW / cm 2 and irradiation time 60 seconds (cumulative light amount 528 mJ / cm 2 ). The light source was an LED, and the peak wavelength of the irradiated light was 340 nm. As a result, the coated layer was photocured, and an adhesive sheet of Example 1 (thickness 20 μm) sandwiched by the base sheet and the release liner was obtained. Note that the illuminance of the light was measured using an illuminance meter (manufactured by TOPCON TECHNOHOUSE, UD-T3040T2) at a position near the surface of the base sheet to which the ultraviolet light was directed.

[0208] [Examples 2 to 8, Comparative Examples 1 and 2]

[0209] The photocurable composition used and the light irradiation conditions were changed as shown in Table 3, and otherwise, adhesive sheets of Examples 2 to 8 and Comparative Examples 1 and 2 were obtained by the same method as in Example 1.

[0210] [Method of Evaluation]

[0211] [Mw of Polymer]

[0212] A sample having the same composition as the photocurable composition used in Examples 1 to 8 and Comparative Examples 1 and 2 was prepared except that no crosslinking agent was included. The sample was irradiated with light under the conditions of the corresponding example and comparative example. As a result, the monomer components included in the sample were polymerized to form a polymer. The Mw of this polymer was measured. The Mw was measured by GPC. The measurement device and the measurement conditions were set as follows. Note that the measurement device and the measurement conditions were set to be different between the NVP-containing composition and the NVP-free composition.

[0213] (NVP-free composition)

[0214] • Analysis device: HLC-8320 GPC, manufactured by Tosoh Corporation

[0215] • Chromatography column: TSKgel GMH-H(S) x 2, manufactured by Tosoh Corporation

[0216] • Column size: 7.8 mmφ x 30 cm, total 60 cm

[0217] • Column temperature: 40°C

[0218] • Flow rate: 0.5 mL / min

[0219] • Injection volume: 100 μL

[0220] • Eluent: Tetrahydrofuran

[0221] • Detector: Differential refractometer (RI)

[0222] • Standard sample: Polystyrene

[0223] (NVP-containing composition)

[0224] • Analysis device: Agilent 1200 manufactured by Agilent Technologies

[0225] • Column: TSKgel SuperAWM-H + superAW4000 + superAW2500 manufactured by Tosoh Corporation

[0226] • Column size: 6.0 mmφ x 15 cm each, total 45 cm

[0227] • Column temperature: 40°C

[0228] • Flow rate: 0.4 mL / min

[0229] • Injection volume: 40 μL

[0230] • Eluent: N,N-dimethylformamide (DMF)

[0231] • Detector: Differential refractometer (RI)

[0232] • Standard sample: Polystyrene

[0233] <Gel fraction>

[0234] The gel fraction of each adhesive sheet of the examples and comparative examples was measured by the above method.

[0235] <Polymerization rate of monomer group>

[0236] The polymerization rate of each adhesive sheet of the examples and comparative examples was calculated from the change in the weight of the adhesive sheet before and after heat drying at 130°C for 2 hours. Specifically, the weight of the adhesive sheet immediately after the substrate sheet and the release liner were peeled was set as W0 (weight before drying), and the weight of the adhesive sheet at a point in time after the above heat and cooling at ordinary temperature (23°C) for about 20 minutes was set as W1 (weight after drying), and the polymerization rate (%) was calculated by the formula: Polymerization rate (%) = W1 / W0 x 100. In addition, the following determination was made based on the calculated polymerization rate.

[0237] A: The polymerization rate is 98.5% or more

[0238] B: polymerization rate of 98.0% or more and less than 98.5%

[0239] C: polymerization rate of 97.5% or more and less than 98.0%

[0240] D: polymerization rate of less than 97.5%

[0241] <Reliability test>

[0242] (Production of polarizing film)

[0243] Between the rolls having different speed ratios, a polyvinyl alcohol film having a thickness of 80 μm was dyed in an iodine solution having a concentration of 0.3% at a temperature of 30°C for 1 minute while being stretched to 3 times. Next, the film was immersed in an aqueous solution containing boric acid at a concentration of 4% and potassium iodide at a concentration of 10% at a temperature of 60°C for 0.5 minutes while being stretched to a total stretch ratio of 6 times. Next, after being washed by immersion in an aqueous solution containing potassium iodide at a concentration of 1.5% at a temperature of 30°C for 10 seconds, the film was dried at 50°C for 4 minutes, whereby a polarizer having a thickness of 28 μm was obtained. A transparent protective film having a thickness of 30 μm formed of a modified acrylic polymer having a lactone ring structure was attached to one side of the polarizer using a polyvinyl alcohol-based adhesive. Further, a transparent protective film having a thickness of 47 μm formed on a cellulose triacetate film (Konica Minolta, trade name "KC4UY") with a hard coat layer (HC) was attached to the other side of the polarizer using a polyvinyl alcohol-based adhesive. The film was heated and dried in an oven set at 70°C for 5 minutes, whereby a polarizing film was produced. Further, the surface of the polarizing film on the side of the transparent protective film formed of the modified acrylic polymer was subjected to corona treatment at a discharge amount of 63 W / m 2 ·min.

[0244] (Production of polarizing film with adhesive sheet)

[0245] Each of the adhesive sheets produced in the examples and comparative examples was arranged on the exposed surface of the polarizing film, whereby a polarizing film with an adhesive sheet was produced. Note that the polarizing film was arranged so that the surface on the side of the transparent protective film formed of the modified acrylic polymer was in contact with the adhesive sheet.

[0246] <Reliability test (85°C)>

[0247] For the produced polarizing film with adhesive sheet, reliability (85°C reliability) was evaluated by the following method. First, the polarizing film with adhesive sheet was cut into a long strip shape of 228 mm in the longitudinal direction x 128 mm in the lateral direction to produce a test piece. Next, the test piece was attached to the surface of an alkali-free glass (Corning Corporation, trade name "EG-XG") having a thickness of 0.7 mm using the adhesive sheet. The attachment of the test piece to the alkali-free glass was performed using a laminator. After the test piece was attached, the alkali-free glass and the adhesive sheet were homogenized by being contained in an autoclave at 50°C and 0.5 MPa for 15 minutes, and the adhesive sheet was made to adhere to the alkali-free glass. Next, the test piece was subjected to a heat treatment at 85°C for 500 hours under atmospheric pressure. The end portion of the test piece was observed with an optical microscope, and the presence or absence of peeling from the end portion of the test piece and bubbling in the vicinity of the end portion was confirmed.

[0248] A: No peeling and bubbling that affected image display were confirmed

[0249] B: There was slight bubbling in the end portion, but it was not at a level that affected image display

[0250] C: There were multiple bubbles in the end portion, but it was not at a level that affected image display

[0251] D: There was peeling and / or bubbling that affected image display

[0252] E: There was peeling and / or bubbling that significantly affected image display

[0253] <Reliability Test (95°C)>

[0254] The temperature of the heat treatment was changed from 85°C to 95°C, and otherwise, 95°C reliability was evaluated by the same method as the 85°C reliability. The classification A to E of the evaluation items was set to be the same as the 85°C reliability.

[0255] <Paste Offset Amount (85°C)>

[0256] The polarizing film with adhesive sheet produced in the evaluation of the reliability test was cut into a long strip shape of 228 mm in the longitudinal direction x 128 mm in the lateral direction to produce a test sample. Next, after the test sample was subjected to a heat test at 85°C for 500 hours, the amount of overflow of the adhesive sheet with respect to the end surface of the polarizing film was measured based on observation with an optical microscope using an objective lens of 20 times, and this was taken as the paste offset amount (85°C). At the time of observation, the transmitted light was set to 0 (zero), and adjustment was made so that only reflected light was present.

[0257] The evaluation results are shown in Table 4 below. Note that for the polymerization rate, the numerical value was shown together with the determination results of A to D.

[0258]

[0259] As shown in Table 4, in the adhesive sheet of the example, an increase in the polymerization rate was achieved while an improvement in reliability in a high-temperature environment was achieved, as compared with the adhesive sheet of the comparative example.

[0260] Industrial applicability

[0261] The adhesive sheet-equipped optical film of the present application can be used for optical laminates and image display devices.

Claims

1. An optical film with an adhesive sheet, comprising: an adhesive sheet of photocurable type, and an optical film, the adhesive sheet comprising a polymer having a constitutional unit derived from a nitrogen atom-containing monomer.

2. The optical film with an adhesive sheet according to claim 1, wherein the polymer is a (meth)acrylic polymer.

3. The optical film with an adhesive sheet according to claim 1, wherein the polymer further has a constitutional unit derived from a carboxyl group-containing monomer.

4. The optical film with an adhesive sheet according to claim 1, wherein the weight average molecular weight of the polymer is 600,000 or more, and the polymerization rate of the polymer in the adhesive sheet is 98% or more.

5. The optical film with an adhesive sheet according to claim 1, wherein the adhesive sheet contains a silane coupling agent.

6. The optical film with an adhesive sheet according to claim 1, wherein the thickness of the adhesive sheet is 30 μm or less.

7. The optical film with an adhesive sheet according to claim 1, wherein the content of a solvent in the adhesive sheet is 5% by weight or less.

8. The optical film with an adhesive sheet according to claim 1, wherein the adhesive sheet is in contact with the optical film.

9. The optical film with an adhesive sheet according to claim 1, wherein the optical film is a polarizing film.

10. An optical laminate comprising the optical film with an adhesive sheet according to any one of claims 1 to 9.

11. An image display device comprising the optical film with an adhesive sheet according to any one of claims 1 to 9. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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