JP2024146808A - POLARIZING FILM WITH ADHESIVE SHEET, OPTICAL LAMINATE AND IMAGE DISPLAY DEVICE - Google Patents

Abstract

[Problem] To provide an optical film with an adhesive sheet that is suitable for use in an image display device that may be exposed to a high-temperature environment while having a photocurable adhesive sheet. [Solution] The optical film with an adhesive sheet provided comprises a photocurable adhesive sheet and an optical film. The adhesive sheet contains a polymer having a structural unit derived from a nitrogen atom-containing monomer. The polymer may be a (meth)acrylic polymer. [Selected Figure] Figure 1

Description

The present invention relates to a polarizing film with an adhesive sheet, an optical laminate, and an image display device.

Various image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices, generally include an optical laminate including an optical film such as a polarizing film and an adhesive sheet. Adhesive sheets are usually used to bond the optical films included in the optical laminate and to bond the optical laminate to an image display panel. Typical adhesive sheets are sheets obtained by curing a monomer group including an acrylic monomer, a silicone monomer, etc., through polymerization and crosslinking. Patent Document 1 discloses a polarizing film with an adhesive sheet, which includes an adhesive sheet formed from a photocurable composition (hereinafter referred to as a photocurable adhesive sheet) and a polarizing film as an optical film. A type of adhesive sheet different from the photocurable type is a heat-curable adhesive sheet formed by curing a layer containing an adhesive composition and a solvent by heat.

JP 2021-56510 A

When a photocurable adhesive sheet is used in an optical film with an adhesive sheet, problems tend to occur with image quality in image display devices that may be exposed to high-temperature environments.

The present invention aims to provide an optical film with a photocurable adhesive sheet that is suitable for use in image display devices that may be exposed to high-temperature environments.

The present invention relates to
The optical film is a photocurable adhesive sheet.
The pressure-sensitive adhesive sheet comprises an optical film with a pressure-sensitive adhesive sheet, the optical film comprising a polymer having a structural unit derived from a nitrogen atom-containing monomer;
to provide.

Further, the present invention relates to
There is provided an optical laminate comprising the above-mentioned optical film with a pressure-sensitive adhesive sheet.

Further, the present invention relates to
The present invention provides an image display device including the above-mentioned optical film with a pressure-sensitive adhesive sheet.

The present invention provides an optical film with a photocurable adhesive sheet that is suitable for use in image display devices that may be exposed to high-temperature environments.

FIG. 1 is a cross-sectional view illustrating a schematic example of an optical film with a pressure-sensitive adhesive sheet of the present invention. FIG. 2 is a schematic diagram for explaining one example of a method for forming a pressure-sensitive adhesive sheet that can be provided in the pressure-sensitive adhesive sheet-attached optical film of the present invention. FIG. 1 is a cross-sectional view illustrating an example of an optical laminate of the present invention. FIG. 1 is a cross-sectional view illustrating an example of an optical laminate of the present invention. FIG. 1 is a cross-sectional view illustrating an example of an optical laminate of the present invention. FIG. 1 is a cross-sectional view that illustrates an example of an image display device of the present invention.

The optical film with a pressure-sensitive adhesive sheet according to the first aspect of the present invention is
The optical film is a photocurable adhesive sheet.
The pressure-sensitive adhesive sheet contains a polymer having a structural unit derived from a nitrogen atom-containing monomer.

In the second aspect of the present invention, for example, in the optical film with a pressure-sensitive adhesive sheet according to the first aspect, the polymer is a (meth)acrylic polymer.

In a third aspect of the present invention, for example, in the optical film with a pressure-sensitive adhesive sheet according to the first or second aspect, the polymer further has a structural unit derived from a carboxyl group-containing monomer.

In a fourth aspect of the present invention, for example, in an optical film with a pressure-sensitive adhesive sheet according to 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 pressure-sensitive adhesive sheet is 98% or more.

In a fifth aspect of the present invention, for example, in an optical film with a pressure-sensitive adhesive sheet according to any one of the first to fourth aspects, the pressure-sensitive adhesive sheet contains a silane coupling agent.

In a sixth aspect of the present invention, for example, in an optical film with a pressure-sensitive adhesive sheet according to any one of the first to fifth aspects, the thickness of the pressure-sensitive adhesive sheet is 30 μm or less.

In the seventh aspect of the present invention, for example, in the optical film with a pressure-sensitive adhesive sheet according to any one of the first to sixth aspects, the solvent content in the pressure-sensitive adhesive sheet is 5% by weight or less.

In the eighth aspect of the present invention, for example, in the optical film with adhesive sheet according to any one of the first to seventh aspects, the adhesive sheet and the optical film are in contact with each other.

In a ninth aspect of the present invention, for example, in the optical film with a pressure-sensitive adhesive sheet according to any one of the first to eighth aspects, the optical film is a polarizing film.

The optical laminate according to the tenth aspect of the present invention comprises an optical film with a pressure-sensitive adhesive sheet according to any one of the first to ninth aspects.

The image display device according to the eleventh aspect of the present invention includes an optical film with a pressure-sensitive adhesive sheet according to any one of the first to ninth aspects.

The present invention will be described in detail below, but the present invention is not limited to the following embodiments, and can be modified as desired without departing from the gist of the present invention.

[Optical film with adhesive sheet]
An example of an optical film with a pressure-sensitive adhesive sheet according to the present embodiment is shown in Fig. 1. The optical film with a pressure-sensitive adhesive sheet 11 in Fig. 1 includes a pressure-sensitive adhesive sheet 1 and an optical film 2. The pressure-sensitive adhesive sheet 1 and the optical film 2 are in contact with each other. The pressure-sensitive adhesive sheet 1 is a photocurable pressure-sensitive adhesive sheet formed from a photocurable composition. The pressure-sensitive adhesive sheet 1 contains a polymer A having a structural unit derived from a nitrogen atom-containing monomer.

According to the study by the present inventors, it was found that one of the factors that causes the deterioration of image quality due to exposure to a high-temperature environment is that the adhesive sheet in the optical laminate and the adherend (adhesive object) in contact therewith tend to peel off at high temperatures. In addition, the deterioration of visibility due to the foaming of the monomer remaining in the adhesive sheet at high temperatures can also be a factor. It is presumed that the photocurable adhesive sheet 1 containing polymer A is suitable for improving the polymerization rate during formation, and that the balance of its stress relaxation properties and cohesive force is suitable for suppressing the above-mentioned peeling at high temperatures. Polymer A is formed by photopolymerization of a photocurable composition containing a nitrogen atom-containing monomer. When a nitrogen atom-containing monomer is present in the photopolymerization system, there is a tendency for the polymerization rate to improve and the molecular weight of the polymer to increase, even when, for example, the cumulative light amount of the irradiated light is small. The above tendency may be contributed to by the fact that the viscosity of the polymerization system increases due to the formation of hydrogen bonds, which suppresses the termination reaction between the growing ends of the polymer, making it easier for the monomer to remain at the end of the growing chain. It is also presumed that the increase in molecular weight contributes to an excellent balance between stress relaxation properties and cohesive strength. If the amount of photopolymerization initiator is increased or the illuminance of light is increased to increase the cumulative amount of light in order to improve the polymerization rate, the molecular weight becomes difficult to increase due to the increased number of radicals generated at the same time. In addition, in a thermosetting adhesive composition, the monomer is dispersed in the solvent, making it difficult for hydrogen bonds to form, and there is also a lot of chain transfer of radicals to the solvent, so the above-mentioned effect of the nitrogen atom-containing monomer is not observed.

<Adhesive sheet>
(Photocurable composition)
The adhesive sheet 1 is formed from a photocurable composition. The photocurable composition usually contains a monomer group and/or a partial polymer of the monomer group. By irradiating the photocurable composition with light, a polymer A is generated from the monomer group and/or the partial polymer, and the adhesive sheet 1 is formed. The monomer group may contain a (meth)acrylic monomer. The content of the (meth)acrylic component in the photocurable composition, i.e., the (meth)acrylic monomer and its partial polymer, may be 50% by weight or more, 60% by weight or more, 70% by weight or more, or even 80% by weight or more. In this case, an acrylic adhesive sheet containing a (meth)acrylic polymer as a main component can be formed. In other words, the polymer A may be a (meth)acrylic polymer. However, as long as the photocurable composition contains a nitrogen atom-containing monomer, the photocurable composition is not limited to the above examples. In this specification, (meth)acrylic means acrylic and methacrylic. (Meth)acrylate means acrylate and methacrylate. In this specification, the term "main component" refers to the component having the largest content. The content of the main component is, for example, 50% by weight or more, and may be 60% by weight or more, 70% by weight or more, or even 80% by weight or more.

An example of a (meth)acrylic monomer is a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms on the side chain. The number of carbon atoms in the alkyl group may be 7 or less, 6 or less, 5 or less, or even 4 or less. The alkyl group may be linear or branched. Examples of (meth)acrylic acid alkyl esters are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate. The (meth)acrylic acid alkyl ester may be n-butyl (meth)acrylate.

The content of the (meth)acrylic acid alkyl ester in the monomer group is, for example, 40% by weight or more, and may be 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, or even 95% by weight or more. In calculating the content, the weight of the partially polymerized product is converted into the weight of each monomer before polymerization.

The monomer group may contain a carboxyl group-containing monomer. In this case, the polymer A further has a constituent unit derived from the carboxyl group-containing monomer. The carboxyl group-containing monomer contributes to improving the viscosity of the photopolymerization system by being present together with the nitrogen atom-containing monomer. The carboxyl group-containing monomer may be a (meth)acrylic monomer, in other words, the (meth)acrylic monomer may contain a 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 of the carboxyl group-containing monomer in the monomer group may be, for example, 10% by weight or less, 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, or even 5% by weight or less. The lower limit of the content is, for example, 0.1% by weight or more, and may 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, or even 4.5% by weight or more. The monomer group may not include a carboxyl group-containing monomer.

The monomer group may contain a hydroxy group-containing monomer. In this case, polymer A further has a structural unit derived from the hydroxy group-containing monomer. The hydroxy group-containing monomer may be a (meth)acrylic monomer, in other words, the (meth)acrylic monomer may contain a hydroxy group-containing monomer. Examples of the hydroxy 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 hydroxy group-containing monomer is preferably 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate. The content of the hydroxyl group-containing monomer in the monomer group is, for example, 10% by weight or less, and may 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, or even 0.1% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.03% by weight or more, or even 0.05% by weight or more. The monomer group may not contain a hydroxyl group-containing monomer.

The monomer group includes nitrogen atom-containing monomers. Nitrogen atom-containing monomers refer to monomers that have at least one nitrogen atom in the molecule (per molecule). In this specification, monomers that have a hydroxyl group and a nitrogen atom in the molecule are classified as nitrogen atom-containing monomers. Monomers that have a carboxyl group and a nitrogen atom in the molecule are classified as carboxyl group-containing monomers.

Preferred examples of the nitrogen atom-containing monomer include N-vinyl cyclic amide and (meth)acrylamide. The nitrogen atom-containing monomer may be used alone or in combination of two or more kinds.

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

In formula (A), R ¹ is a divalent organic group, preferably a divalent saturated or unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (e.g., an alkylene group having 3 to 5 carbon atoms). Note that formula (A) shows that N and R ¹ are directly bonded to each other via a single bond to form a ring structure.

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-morpholinedione, etc. are preferred, more preferably N-vinyl-2-pyrrolidone, N-vinyl-2-caprolactam, and even more preferably N-vinyl-2-pyrrolidone.

Examples of (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, and N,N-dialkyl(meth)acrylamide. Examples of N-alkyl(meth)acrylamide include N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-n-butyl(meth)acrylamide, and N-octylacrylamide. N-alkyl(meth)acrylamides also include (meth)acrylamides having an amino group, such as dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, and dimethylaminopropyl(meth)acrylamide.

Examples of N,N-dialkyl(meth)acrylamides include 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, and N,N-di(t-butyl)(meth)acrylamide.

(Meth)acrylamides also include, for example, various N-hydroxyalkyl (meth)acrylamides. Examples of N-hydroxyalkyl (meth)acrylamides include N-methylol (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, and N-methyl-N-2-hydroxyethyl (meth)acrylamide.

(Meth)acrylamides also include, for example, various N-alkoxyalkyl(meth)acrylamides. Examples of N-alkoxyalkyl(meth)acrylamides include N-methoxymethyl(meth)acrylamide and N-butoxymethyl(meth)acrylamide.

Examples of nitrogen atom-containing monomers other than N-vinyl cyclic amide and (meth)acrylamide include amino group-containing monomers such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; (meth)acryloylmorpholine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine, N-methyl Examples of such monomers include heterocyclic ring-containing monomers such as vinylpyrrolidone; maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimide-based monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-laurylitaconimide, and N-cyclohexylitaconimide; imide group-containing monomers such as succinimide-based monomers such as N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; and isocyanate group-containing monomers such as 2-(meth)acryloyloxyethylisocyanate.

The content of the nitrogen atom-containing monomer in the monomer group is, for example, 40% by weight or less, and may be 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, or even 11% by weight or less. The lower limit of the content is, for example, 5% by weight or more, and may be 7% by weight or more, 8% by weight or more, 9% by weight or more, or even 10% by weight or more.

It is preferable that the monomer group further includes a carboxyl group-containing monomer.

In the photocurable composition, each of the above-mentioned monomers may be contained as a partial polymer. The partial polymer may be either a homopolymer or a copolymer. The photocurable composition may not contain a partial polymer.

The photocurable composition usually contains a photopolymerization initiator. An example of a photopolymerization initiator is a photoradical generator that generates radicals by irradiation with light. The photopolymerization initiator has an absorption coefficient for light with a wavelength of 340 nm of, for example, 0.1 L/(g·cm) or more, and may be 0.5 L/(g·cm) or more, 1.0 L/(g·cm) or more, 3.0 L/(g·cm) or more, or even 5.0 L/(g·cm) or more. The upper limit of this absorption coefficient is not particularly limited, and is, for example, 50 L/(g·cm) or less. The absorption coefficient of the photopolymerization initiator is a calculated value from the absorbance of a 0.01 mg/mL methanol solution measured with a visible-ultraviolet spectrophotometer using a quartz cell with an optical path length of 1 cm.

Examples of photopolymerization initiators include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzil dimethyl ketal; substituted benzoin ethers such as anisole methyl ether; substituted acetophenones such as 2,2-diethoxyacetophenone and 2,2-dimethoxy-2-phenylacetophenone; α-hydroxyalkylphenones such as 1-hydroxycyclohexyl-phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, and 2,2'-dihydroxy-2,2'-dimethyl-1,1'-[methylenebis(4,1-phenylene)]bis(propan-1-one); and 2-methyl-2-hydroxypropiophenone. substituted alpha-ketols such as 2-naphthalenesulfonyl chloride; 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, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and 2,4-diethylthioxanthone. thioxanthone 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-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy-naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, 2,4-tri triazine-based compounds such as chloromethyl-(4'-methoxystyryl)-6-triazine; oxime ester-based compounds such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene)hydroxylamine; phosphine-based compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; quinone-based compounds such as 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone; borate-based compounds; carbazole-based compounds; imidazole-based compounds; and titanocene-based compounds. The photocurable composition may contain one or more photopolymerization initiators. α-Hydroxyalkylphenones tend to have high absorption of light with a wavelength of 340±10 nm.

Another example of the photopolymerization initiator is a compound having a chemical structure shown in the following formula (1) (hereinafter, referred to as chemical structure X) in the molecule.

R ¹ and R ² in the formula (1) are each independently a C1 to C8 alkyl group; a C1 to C4 alkyl group in which a hydrogen atom is substituted by -OH, a C1 to C4 alkoxy group, -CN, -COOR ⁵¹ , -OOCR ⁵² , or -NR ⁵³ R ⁵⁴ ; a C3 to C6 alkenyl group; or -CH ₂ -C ₆ H ₄ -R ^55. R ¹ and R ² may be bonded to each other to form a C2 to C9 alkylene group, a C3 to C6 oxyalkylene group, or an azaalkylene group. R ⁵¹ is a C1 to C8 alkyl group. R ⁵² is a C1 to C4 alkyl group. R ⁵³ and R ⁵⁴ are each independently a hydrogen atom, a C1-C12 alkyl group, a C2-C4 alkyl group in which a hydrogen atom is substituted with at least one group 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 bonded to each other to form a C3-C9 alkylene group which may be 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, -CH ₂ CH ₂ -COOR ⁶¹ or -CH ₂ CH ₂ CN. R ⁶¹ is a C1 to C4 alkyl group.

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 group 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. R ⁵⁷ and R ⁵⁸ may be bonded to each other to form a C3-C9 alkylene group which may be interrupted by -O- or -N(R ⁶⁴ )-. R ⁶² is a C1-C6 alkyl group. R ⁶³ is a C1-C4 alkyl group. R ⁶⁴ is a hydrogen atom, a C1 to C4 alkyl group, an allyl group, a C1 to C4 hydroxyalkyl group, --CH ₂ CH ₂ --COOR ⁶⁵ or --CH ₂ CH ₂ CN. R ⁶⁵ is a C1 to C4 alkyl group.

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

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

R ¹ and R ² may be, independently of each other, a C1 to C8 alkyl group, a C3 to C6 alkenyl group, or a C1 to C8 alkyl group. R ¹ and R ² may be, independently of each other, a C1 to C4 alkyl group, a C1 to C3 alkyl group, or a C1 to C2 alkyl group. R ¹ and R ² may be a methyl group.

R ¹ and R ² may be the same.

X may be -OR ^56. R ⁵⁶ may be a hydrogen atom or a C1 to C8 alkyl group, or may be a hydrogen atom. In other words, X may be -OH.

R ¹ , R ² and X may be any combination of the preferred examples given above.

Chemical structure X may be a structure shown in the following formula (2): In the chemical structure X of formula (2), when a hydrogen atom substitution structure is bonded to the carbon atom marked with *, the substitution structure and the ^-COCR1XR2 group in formula ( ² ) are in a para-position relationship with respect to the benzene ring of chemical structure X.

The photopolymerization initiator may be a compound having two or more chemical structures X in one molecule.

The photopolymerization initiator may 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 located at both ends of the molecule of the photopolymerization initiator, respectively. More specifically, the two chemical structures X are bonded to each other via -A- at the carbon atom of the phenylene group represented by * above.

R ¹ ' and R ² ' in formula (3) are possible groups for R 1 and R ² , independently of each other and of R 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.

X' in formula (3) is a possible group for X, independent of X in formula (1). X' and X may be the same.

A is --O--, --CYR ³ --, or --C(CH ₃ )R ⁴ .

Y is a hydrogen atom, -Cl, -Br, -O-R ⁷¹ , -NR ⁷² R ⁷³ or -S-R ^74. R ³ is a hydrogen atom, a C1 to C8 alkyl group, a C3 to C6 alkenyl group, a benzyl group, -CH ₂ -C ₆ H ₄ -R ⁷⁵ or a phenyl group. R ⁴ is a C1 to C6 alkyl group or alkylene group, and this alkylene group is bonded to a carbon atom of the phenylene group in the compound of formula (3).

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

The alkyl group, alkenyl group, acyl group, hydroxyalkyl group, methoxyalkyl group, alkoxy group, alkyl portion of the phenylalkyl group, and alkylene group described in the explanation of formula (3) may be unbranched or branched.

Preferred examples of R ¹ , R ² , R ¹ ' and R ² ' in formula (3) are the same as the preferred examples of R ¹ and R ² described above in the explanation of formula (1). Preferred examples of X' in formula (3) are the same as the preferred examples of X described above in the explanation of formula (1). A may be -CYR ³ -. Y may be a hydrogen atom. R ³ may be a hydrogen atom. A may be -CYR ³ - and Y and R ³ may both be hydrogen atoms. In other words, A may be -CH ₂ -.

R ¹ , R ² , R ¹ ', R ² ', X, X' and A in formula (3) may be any combination of the preferred examples given above.

The photopolymerization initiator may be a compound represented by the following formula (4): The compound of formula (4) is a type of compound of formula (3).

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

The photopolymerization initiators shown in 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). The photopolymerization initiator may be at least one selected from these groups.

Specific examples of photopolymerization initiators 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-methylpropan-1-one. Of these, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)2-methylpropan-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 Resin).

The amount of the photopolymerization initiator in the photocurable composition is, for example, 20 parts by weight or less, and may 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, or even 0.2 parts by weight or less, based on 100 parts by weight of the total of the monomer group and its partial polymer. The lower limit of the amount of the photopolymerization initiator is, for example, 0.01 parts by weight or more, and may be 0.03 parts by weight or more, 0.05 parts by weight or more, or even 0.06 parts by weight or more, based on 100 parts by weight of the total of the monomer group and its partial polymer.

The photocurable composition may contain a crosslinking agent. An example of the crosslinking agent is a polyfunctional monomer having two or more polymerizable functional groups in one molecule. The polyfunctional monomer may be a (meth)acrylic monomer. An example of the polyfunctional monomer is a monomer having two or more C=C bonds in one molecule, and a monomer having one or more C=C bonds and one or more polymerizable functional groups such as epoxy groups, aziridine groups, oxazoline groups, hydrazine groups, and methylol groups in one molecule. The polyfunctional monomer is preferably a monomer having two or more C=C bonds in one molecule.

Examples of polyfunctional monomers include (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate (N DDA), 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, and other polyfunctional acrylates (such as ester compounds of polyhydric alcohols and (meth)acrylic acid); allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, and hexyl di(meth)acrylate. The polyfunctional monomer is preferably a polyfunctional acrylate, and more preferably 1,9-nonanediol diacrylate, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

The amount of the crosslinking agent varies depending on the molecular weight, the number of functional groups, etc., but may be, for example, 5 parts by weight or less, 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, or even 0.15 parts by weight or less, relative to 100 parts by weight of the total of the monomer group and its partial polymer. The lower limit of the amount may be, for example, 0.01 parts by weight or more, 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, or even 0.1 parts by weight or more. The photocurable composition may not contain a crosslinking agent.

The photocurable composition may contain additives other than those mentioned above. Examples of additives include chain transfer agents, silane coupling agents, viscosity modifiers, tackifiers, plasticizers, softeners, antioxidants, fillers, colorants, antioxidants, surfactants, antistatic agents, and ultraviolet absorbers. The photocurable composition may not contain additives.

Examples of silane coupling agents include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

The silane coupling agent may be an oligomeric silane coupling agent. An oligomeric silane coupling agent usually has multiple alkoxysilyl groups in one molecule. Specific examples of oligomeric silane coupling agents are 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" manufactured by Shin-Etsu Silicone Co., Ltd. The oligomeric silane coupling agent may have a reactive functional group. Examples of the reactive functional group are an epoxy group, a mercapto group, an acid anhydride group and an amino group. Among them, those having an epoxy group are preferred, and those having multiple epoxy groups in one molecule are more preferred. Examples of oligomeric silane coupling agents having an epoxy group are the above-mentioned "X-41-1053", "X-41-1056" and "X-41-1059A". Examples of oligomeric silane coupling agents having a mercapto group are the above-mentioned "X-41-1805", "X-41-1810" and "X-41-1818". An example of an oligomeric silane coupling agent having an acid anhydride group is the above-mentioned "X-24-9591F". An example of an oligomeric silane coupling agent having an amino group is the above-mentioned "X-40-2651".

The silane coupling agent may be an acetoacetyl group-containing silane coupling agent (e.g., product name "A-100" manufactured by Soken Chemical Industries, Ltd.).

When the photocurable composition contains a silane coupling agent, the amount of the silane coupling agent is, for example, 5 parts by weight or less, and may 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, or even 0.05 parts by weight or less, based on 100 parts by weight of the total of the monomer group and its partial polymer. The photocurable composition does not have to contain a silane coupling agent.

The viscosity of the photocurable composition is preferably 5 to 100 poise. Photocurable compositions having a viscosity in the above range are particularly suitable for forming the adhesive sheet 1.

The content of the solvent in the photocurable composition is, for example, 5% by weight or less, and may be 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, or even 0.5% by weight or less. The photocurable composition may be substantially free of solvent. "Substantially free of solvent" means that solvents derived from additives and the like are permitted 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. The content of the solvent in the adhesive sheet 1 may be within the above range. The adhesive sheet 1 may be substantially free of solvent.

(Manufacturing method of adhesive sheet)
The pressure-sensitive adhesive sheet 1 can be formed, for example, by irradiating light 24 onto a first laminate 20 including, in this order, a base sheet 21, a coating layer 22 containing a photocurable composition, and a release liner 23 (see FIG. 2). The coating layer 22 is irradiated with light 24 and hardened to become the pressure-sensitive adhesive sheet 1. Irradiation with light 24 is typically performed from the side of the base sheet 21. At this time, the light 24 passes through the base sheet 21 and reaches the coating layer 22, hardening the coating layer 22. However, irradiation with light 24 may be performed from the side of the release liner 23, or may be performed from both the side of the release liner 23 and the side of the base sheet 21.

The formed adhesive sheet 1 is sandwiched between the base sheet 21 and the release liner 23 until the release liner 23 is peeled off, constituting part of the second laminate 27. By peeling the release liner 23 from the second laminate 27, a third laminate 25 including the base sheet 21 and the adhesive sheet 1 is obtained. In the third laminate 25, the surface of the adhesive sheet 1 is exposed to the outside. An optical film can be laminated onto the exposed surface of the adhesive sheet 1 directly or via another layer.

The light 24 is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light may contain light having a wavelength in the same region as the absorption wavelength of the photopolymerization initiator contained in the photocurable composition. Light with a wavelength of 300 nm or less cut by a filter or the like may be irradiated, and cutting short wavelength light is suitable for suppressing deterioration of the base sheet 21 and/or the release liner 23 due to the light 24. The light source 28 of the light 24 is, for example, a light irradiation device equipped with an ultraviolet irradiation lamp. Examples of ultraviolet irradiation lamps are ultraviolet LEDs, low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, extra high pressure mercury lamps, metal halide lamps, xenon lamps, microwave excited mercury lamps, black light lamps, chemical lamps, germicidal lamps, low pressure discharge mercury lamps, and excimer lasers. Two or more ultraviolet irradiation lamps may be combined. With ultraviolet LEDs, the band of ultraviolet light irradiated can be narrower than when other light sources are used.

The light source 28 may be an LED. Compared to a black light source, an LED not only has an easily adjustable illuminance, but also tends to have a longer light source life. Compared to a black light source using mercury, an LED is superior in terms of reducing environmental impact. When an ultraviolet LED is used as the light source, an LED having a peak wavelength of 325 to 350 nm may be selected. According to the inventors' study, the use of an LED having a peak wavelength of 325 to 350 nm may contribute to at least one of the following: an improvement in the polymerization rate of the monomer group in the adhesive sheet 1, an improvement in the molecular weight of the polymer A, and a reduction in the amount of remaining photopolymerization initiator, compared to, for example, the use of a black light source. Furthermore, an LED that emits light 14 with a peak wavelength of 325 nm to 350 nm tends to generate less heat and to control the temperature of the coating layer 22 more easily than an LED that emits light with a peak wavelength of about 365 nm. As far as the inventors know, no examples of producing adhesive sheets using LEDs that emit light with a peak wavelength of 325 nm to 350 nm have been reported.

As an LED having a peak wavelength in the range of 325 to 350 nm, an LED having a peak wavelength of 340±10 nm (hereinafter referred to as LED 340) may be selected.

Focusing on the peak wavelength of the light 24, the peak wavelength of the light 24 irradiated to the first laminate 20 (specifically, the coating layer 22) may be 325 nm to 350 nm. The peak wavelength of the light 24 is preferably 340 ± 10 nm (330 nm to 350 nm), may be 340 ± 5 nm (335 nm to 345 nm), may be 340 ± 2 nm (338 nm to 342 nm), or may be 340 nm. The peak wavelength means the wavelength at which the intensity is at a maximum value in the spectrum showing the relationship between the wavelength and intensity of the light 24. The light 24 may further have a peak wavelength in a wavelength range other than 325 nm to 350 nm, but preferably does not have one.

The illuminance of the light 24 irradiated to the first laminate 20 (specifically, the coating layer 22) is, for example, 2.0 to 30 mW/cm ^2. The illuminance may be 2.5 mW/cm ² or more, 3.0 mW/cm ² or more, 3.5 mW/cm ² or more, 4.0 mW/cm ² or more, 5.0 mW/cm ² or more, 6.0 mW/cm ² or more, 7.0 mW/cm ² or more, 8.0 mW/cm ² or more, 9.0 mW/cm ² or more, or even 10 mW/cm ² or more. The upper limit of the illuminance is, for example, 25 mW/cm ² or less, 20 mW/cm ² or less, or even 15 mW/cm ² or less.

The time for which the light 24 is irradiated to the first laminate 20 (specifically, the coating layer 22) is, for example, 10 seconds to 1000 seconds, and may be 60 seconds or more, 100 seconds or more, 150 seconds or more, 200 seconds or more, 250 seconds or more, or even 300 seconds or more. The upper limit of the time is, for example, 800 seconds or less, and may be 600 seconds or less, 500 seconds or less, 400 seconds or less, 350 seconds or less, 300 seconds or less, or even 250 seconds or less. The irradiation of the light 24 may be continuous or intermittent.

The integrated light amount of the light 24 on the first laminate 20 (specifically the coating layer 22) is, for example, 25 mJ/cm ² or more, 100 mJ/cm ² or more, 250 mJ/cm ² or more, 500 mJ/cm ² or more, 750 mJ/cm ² or more, 850 mJ/cm ² or more, 1000 mJ/cm ² or more, 1250 mJ/cm ² or more, or even 1500 mJ/cm ² or more. The upper limit of the integrated light amount is not particularly limited, and may be, for example, 3000 mJ/cm ² or less, 2500 mJ/cm ² or less, 2000 mJ/cm ² or less, 1750 mJ/cm ² or less, 1500 mJ/cm ² or less, 1250 mJ/cm ² or less, or even 1000 mJ/cm ² or less. The pressure-sensitive adhesive sheet 1 is suitable for formation with a low integrated light amount, and therefore the pressure-sensitive adhesive sheet-attached optical film 11 has excellent productivity.

An example of the substrate of the release liner 23 (hereinafter, "liner substrate") is a resin film. Examples of resins that may be contained in the liner substrate are polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

The release liner 23 may have a layer other than the liner substrate. The release liner 23 may have a release layer. The release liner 23 may have, for example, a liner substrate and a release layer formed on one side of the liner substrate. This release liner 23 can be used so that the release layer is on the coating layer 22 side. The release layer is typically a cured layer of a release agent composition containing a release agent. As the release agent, 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 can be used.

The release liner 23 may be in sheet or elongated form.

An example of the base sheet 21 is a resin film. Examples of resins contained in the base sheet 21 are the same as the examples of resins that can be contained in the liner base material.

The thickness of the base sheet 21 is, for example, 10 to 200 μm, and may be 25 to 150 μm.

The base sheet 21 may have a release layer on the surface on the side of the coating layer 22. Examples of the release layer that may be provided on the base sheet 21 are the same as the examples of the release layer that may be provided on the release liner 23. Both the release liner 23 and the base sheet 21 may have a release layer.

For the base sheet 21, a sheet that has a greater peel strength with respect to the adhesive sheet 1 than the release liner 23 can usually be selected.

The base sheet 21 may be in the form of a sheet or a long piece.

The first laminate 20 can be formed, for example, by forming a coating layer 22 on a base sheet 21 (or a release liner 23) and then placing the release liner 23 (or base sheet 21) on the formed coating layer 22. Alternatively, the first laminate 20 can be formed by applying a photocurable composition in a poured manner into the space between the base sheet 21 and the release liner 23, which are held at a predetermined distance so that their main surfaces face each other.

Various coating methods can be used to form the coating layer 22, including roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coating.

The thickness of the coating layer 22 can be adjusted according to the desired thickness of the adhesive sheet 1, and may be, for example, 5 to 100 μm, 5 to 50 μm, 5 to 25 μm, or even 5 to 20 μm.

The first laminate 20 may include a long base sheet 21, a long coating layer 22, and a long release liner 23, or in other words, may be long. The long first laminate 20 can be obtained, for example, by forming the coating layer 22 between the base sheet 21 and the release liner 23 while conveying them from a roll.

The Mw of polymer A contained in adhesive sheet 1 is, for example, 600,000 or more, and may be 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 million or more, 1.1 million or more, 1.2 million or more, 1.3 million or more, or even 1.4 million or more. There is no particular limit to the upper limit of Mw, and it is, for example, 3 million or less. The Mw of polymer A is determined from the value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

The polymerization rate of the monomer group in the adhesive sheet 1 may be 97.5% or more, 98% or more, or even 98.5% or more. The upper limit of the polymerization rate is, for example, 99.99% or less. A high polymerization rate can contribute, for example, to suppressing the odor of the adhesive sheet 1.

In the adhesive sheet 1, both the molecular weight of the polymer and the polymerization rate of the monomer group can be increased. The weight average molecular weight (Mw) of the polymer contained in the adhesive sheet 1 may be 600,000 or more, and the polymerization rate of the monomer group in the adhesive sheet 1 may be 98% or more. The Mw and polymerization rate may each be within the numerical ranges described above.

The gel fraction of the adhesive sheet 1 is, for example, 55% or more, and may 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, or even 85% or more. The upper limit of the gel fraction may be 95% or less, 94% or less, 93% or less, 92% or less, 91% or less, 90% or less, or even 89% or less.

The gel fraction of the adhesive sheet 1 can be evaluated as follows. A test piece of about 0.1 g is taken from the adhesive sheet 1, wrapped in a polytetrafluoroethylene porous sheet (average pore size 0.2 μm, product name "NTF1122", manufactured by Nitto Denko Corporation), and then tied with a kite string to obtain a measurement sample. Next, the weight of the obtained measurement sample (weight C before immersion) is measured. The weight C before immersion is the total weight of the test piece, the polytetrafluoroethylene porous sheet, and the kite string. Separately from this, the bag weight B, which is the total weight of the polytetrafluoroethylene porous sheet and the kite string, is measured. Next, the measurement sample is placed in a container with a volume of 50 mL filled with ethyl acetate and left to stand at 23 ° C for 7 days. After standing, the measurement sample is removed from the container and transferred to an aluminum cup, and the ethyl acetate is removed by drying at 130 ° C for 2 hours using a dryer. The weight of the measurement sample after drying (weight A after immersion) is measured. The value calculated from the following formula is specified as the gel fraction of the adhesive sheet 1.
Gel fraction (%)=(A−B)/(C−B)×100

The thickness of the adhesive sheet 1 is, for example, 2 to 70 μm. The thickness may be 50 μm or less, 40 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the thickness may be 5 μm or more, 10 μm or more, or even 15 μm or more. A thin adhesive sheet 1, for example, an adhesive sheet 1 having a thickness of 30 μm or less, is susceptible to polymerization inhibition due to oxygen in the environment when formed by photocuring. On the other hand, the adhesive sheet 1 is suitable for formation with a low integrated light amount, in other words, suitable for formation by photocuring in a short time. Therefore, even when the adhesive sheet 1 is thin, the influence of polymerization inhibition can be suppressed. In addition, the adhesive sheet 1 is suitable for suppressing foaming and peeling from the adherend in a high temperature environment, even when the adhesive sheet 1 has a thickness of, for example, 30 μm or less. The adherend is, for example, a glass substrate.

<Optical film>
Examples of the optical film 2 include a polarizing film, a retardation film, and a laminated film including a polarizing film and/or a retardation film. However, the optical film 2 is not limited to the above examples. The optical film 2 may include a film made of glass.

The optical film 2 may be a polarizing film, and the adhesive sheet 1 may be in contact with the polarizing film. Among optical films, polarizing films tend to have a large tendency to undergo dimensional change due to heat. Dimensional change in the polarizing film may cause peeling from the adhesive film. For this reason, the present invention is particularly advantageous when the optical laminate further comprises a polarizing film.

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

The polarizer is not particularly limited, and examples thereof include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and partially saponified ethylene-vinyl acetate copolymer films, which are uniaxially stretched after adsorbing dichroic substances such as iodine and dichroic dyes; and polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. Polarizers are typically made of polyvinyl alcohol films (polyvinyl alcohol films include partially saponified ethylene-vinyl acetate copolymer films) and dichroic substances such as iodine.

The thickness of the polarizer is not particularly limited, and may be, for example, 80 μm or less, 50 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the thickness of the polarizer is not particularly limited, and may be, for example, 1 μm or more, 5 μm or more, 10 μm or more, or even 15 μm or more. A thin polarizer (for example, a thickness of 20 μm or less) suppresses dimensional changes and can contribute to improving the durability of the optical laminate, particularly the durability at high temperatures.

As the material of the protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture blocking property, isotropy, etc. is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The material of the protective film may be a thermosetting resin or an ultraviolet-curing resin such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone. When the polarizing film has two protective films, the materials of the two protective films may be the same or different from each other. For example, a protective film made of a thermoplastic resin may be attached to one main surface of the polarizer via an adhesive, and a protective film made of a thermosetting resin or an ultraviolet-curing resin may be attached to the other main surface of the polarizer. The protective film may contain one or more types of additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, colorants, etc.

The thickness of the protective film can be determined as appropriate, but is generally about 5 to 200 μm, taking into consideration strength, ease of handling, thinness, etc.

The polarizer and the protective film are usually adhered to each other via a water-based adhesive or the like. Examples of water-based adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl latex, water-based polyurethane, water-based polyester, etc. Examples of adhesives other than the above-mentioned adhesives include ultraviolet-curable adhesives and electron beam-curable adhesives. Electron beam-curable polarizing film adhesives exhibit suitable adhesion to various protective films. The adhesive may contain a metal compound filler.

In polarizing films, instead of a protective film, a retardation film or the like can be formed on the polarizer. Another protective film can be further provided on the protective film, or a retardation film or the like can be provided.

The protective film may have a hard coat layer on the surface opposite to the surface attached to the polarizer, and may also be treated for the purposes of anti-reflection, anti-sticking, diffusion, anti-glare, etc.

The polarizing film may be a circular polarizing film.

The thickness of the polarizing film is, for example, 500 μm or less, and may be 300 μm or less, 200 μm or less, 100 μm or less, or even 60 μm or less. The lower limit of the thickness is, for example, 10 μm or more, and may be 25 μm or more, or even 40 μm or more.

A retardation film is a film that has birefringence in the in-plane direction and/or the thickness direction. Retardation films are, for example, stretched resin films, or films in which liquid crystal material is oriented and fixed.

The retardation film may be a λ/4 plate, a λ/2 plate, an anti-reflection retardation film (see, for example, paragraphs 0221, 0222, and 0228 of JP 2012-133303 A), a retardation film for compensating for viewing angles (see, for example, paragraphs 0225 and 0226 of JP 2012-133303 A), or an inclined orientation retardation film for compensating for viewing angles (see, for example, paragraph 0227 of JP 2012-13303 A). The retardation film is not limited to the above examples as long as it has birefringence in the in-plane direction and/or the thickness direction. There are also no limitations on the retardation value, arrangement angle, three-dimensional birefringence, whether the retardation film is single-layered or multi-layered, and the like of the retardation film. Any known film can be used for the retardation film.

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

The optical film 2 may be a single layer or a laminated film composed of two or more layers. When the optical film 2 is a laminated film, the adhesive sheet 1 may be used to bond each layer.

The optical film 11 with adhesive sheet may have layers other than the adhesive sheet 1 and the optical film 2. Other layers may be disposed 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 with each other.

The optical film 11 with adhesive sheet can be used, for example, in an optical laminate or an image display device. However, the uses of the optical film 11 with adhesive sheet are not limited to the above examples.

[Optical laminate]
An example of the optical laminate of this embodiment is shown in Fig. 3. The optical laminate 30A in Fig. 3 includes the optical film 11 with the adhesive sheet of this embodiment. The optical laminate 30A has a layered structure in which a release liner 3, an adhesive sheet 1, and an optical film 2 are layered in this order. The optical laminate 30A can be used as the optical film 11 with the adhesive sheet by peeling off the release liner 3.

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, acrylic, polystyrene, polyamide, and polyimide. The surface of the release liner 3 that comes into contact with the adhesive sheet 1 may be subjected to a release treatment. The release treatment is, for example, a treatment using a silicone compound. However, the release liner 3 is not limited to the above example. The release liner 3 is peeled off when the optical laminate 30A is used, for example, when it is attached to the image forming layer.

Another example of the optical laminate of this embodiment is shown in FIG. 4. The optical laminate 30B in FIG. 4 includes the optical film 11 with the adhesive sheet of 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 laminated in this order. After the release liner 3 is peeled off, the optical laminate 30B can be used by, for example, attaching it to an image forming layer.

A known adhesive sheet can be used for adhesive sheet 4. Adhesive sheet 1 may also be used for adhesive sheet 4.

Another example of the optical laminate of this embodiment is shown in FIG. 5. The optical laminate 30C in FIG. 5 includes the optical film 11 with the adhesive sheet of 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 laminated in this order. After the release liner 3 is peeled off, the optical laminate 30C can be used by, for example, attaching it to an image forming layer.

The protective film 5 has a function of protecting the optical film 2 (polarizing film 2A), which is the outermost layer, during distribution and storage of the optical laminate 30C and when the optical laminate 30C is incorporated into an image display device. The protective film 5 may also function as a window to the external space when incorporated into an image display device. The protective film 5 is typically a resin film. The resin constituting the protective film 5 is, for example, polyester such as PET, polyolefin such as polyethylene and polypropylene, acrylic, cycloolefin, polyimide, and polyamide, and polyester is preferable. However, the protective film 5 is not limited to the above examples. The protective film 5 may be a glass film or a laminated film including a glass film. The protective film 5 may be subjected to surface treatment such as anti-glare, anti-reflection, and anti-static.

The protective film 5 may be bonded to the optical film 2 by any adhesive. Bonding by an adhesive sheet 1 is also possible.

The optical laminate of this embodiment may include any layer other than the layers described above. The optical laminate of this embodiment may have any configuration as long as it includes an optical film 11 with a pressure-sensitive adhesive sheet.

The optical laminate of this embodiment can be distributed and stored, for example, as a roll of a strip-shaped optical laminate wound up, or as a sheet-shaped optical laminate.

The optical laminate of this embodiment is typically used in image display devices. Image display devices are, for example, EL displays such as liquid crystal displays, organic EL displays, and inorganic EL displays.

[Image display device]
An example of the image display device of this embodiment is shown in Fig. 6. The image display device 31 of Fig. 6 has a laminated 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 retardation film 2B, an adhesive sheet 1, a polarizing film 2A, and a protective film 5 are laminated in this order. The image display device 31 includes the adhesive sheet-attached optical film 11 of Fig. 1, and the optical laminates 30A, 30B, and 30C of Figs. 3 to 5 (excluding the release liner 3). The substrate 7 and the image forming layer 6 may have the same configurations as the substrate and the image forming layer of a known image display device, respectively.

The image display device 31 in FIG. 6 may 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 may be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED), etc. The image display device 31 may be used for home appliance applications, in-vehicle applications, public information display (PID) applications, etc.

The image display device 31 may have any configuration as long as it includes an optical film 11 with a pressure-sensitive adhesive sheet and/or the optical laminate of this embodiment.

The present invention will be described in more detail below with reference to examples. The present invention is not limited to the examples shown below.

[Preparation of Photocurable Composition]
(Monomer Syrup A1)
99.0 parts by weight of n-butyl acrylate (BA), 1.0 part by weight of 4-hydroxybutyl acrylate (HBA), 0.16 parts by weight of Omnirad 184 (manufactured by IGM Resin) and 0.04 parts by weight of Omnirad 819 (manufactured by IGM Resin) as photopolymerization initiators were placed in a four-neck flask. Next, the liquid in the flask was irradiated with ultraviolet light under a nitrogen atmosphere to obtain a monomer syrup A1 in which the monomers were partially photopolymerized. The ultraviolet light irradiation was continued until the viscosity of the liquid in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) became 20 Pa·s.

(Monomer syrups A2 to A4)
Monomer syrups A2 to A4 were prepared in the same manner as for the monomer syrup A1, except that the monomers and photopolymerization initiators were changed as shown in Table 1.

The abbreviations in Table 1 are as follows.
BA: n-butyl acrylate HBA: 4-hydroxybutyl acrylate AA: acrylic acid Omnirad 184: 1-hydroxycyclohexyl-phenyl ketone (Omnirad 184, manufactured by IGM Resin)
Omnirad 819: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819, manufactured by IGM Resins)
Omnirad 127: 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)2-methylpropan-1-one (Omnirad 127, IGM Resin)

(Photocurable compositions C1 to C10)
Next, the monomer syrup, the monomer, the crosslinking agent and the silane coupling agent were mixed so as to have the compositions shown in Table 2 below, thereby obtaining photocurable compositions C1 to C10.

The abbreviations in Table 2 are as follows.
AA: Acrylic acid NVP: N-vinyl-2-pyrrolidone NDDA: 1,9-nonanediol diacrylate KBM403: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicones, product name "KBM-403")
X-41-1056: Epoxy group-containing oligomer type silane coupling agent (manufactured by Shin-Etsu Silicones, product name "X-41-1056")

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

[Preparation of adhesive sheet]
Example 1
(Preparation of release liner)
Addition reaction curing type silicone (LTC761 containing hexenyl group-containing polyorganosiloxane, 30 wt% toluene solution, manufactured by Toray Dow Corning) 30 parts by weight, release control agent (BY24-850 containing unreactive silicone resin, manufactured by Toray Dow Corning) 0.9 parts by weight, and curing catalyst (SRX212 containing platinum catalyst, manufactured by Toray Dow Corning) 2 parts by weight, and toluene / hexane mixed solvent (volume ratio 1: 1) as a dilution solvent were mixed to obtain a silicone-based release agent composition. The concentration of silicone solids in the release agent composition was 1.0 wt%. Next, the release agent composition was applied to one side of a liner substrate (Lumirror XD500P, a polyester film, thickness 75 μm) with a wire bar, and heated at 130 ° C. for 1 minute to produce a release liner having a release layer (thickness 60 nm) on one side.

(Preparation of adhesive sheet)
Monomer syrup C1 was applied to one side of a base sheet (PET separator, manufactured by Mitsubishi Plastics, MRF38) with an applicator to form a coating layer (thickness 20 μm). Next, a release liner was placed on the formed coating layer to obtain a first laminate. The release liner was placed so that the release layer was in contact with the coating layer. Next, light was irradiated from the side of the base sheet in the first laminate under conditions of an illuminance of 8.8 mW/cm ² and an irradiation time of 60 seconds (accumulated light amount 528 mJ/cm ² ). An LED was used as the light source, and the peak wavelength of the irradiated light was 340 nm. As a result, the coating layer was photocured, and the pressure-sensitive adhesive sheet (thickness 20 μm) of Example 1 sandwiched between the base sheet and the release liner was obtained. The illuminance of the light was measured using an illuminometer (manufactured by Topcon Technohouse, UD-T3040T2) at a position near the ultraviolet ray incident surface of the base sheet.

<Examples 2 to 8, Comparative Examples 1 and 2>
Pressure-sensitive adhesive sheets of Examples 2 to 8 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the photocurable composition and light irradiation conditions used were changed as shown in Table 3.

[Evaluation method]
<Polymer Mw>
Samples were prepared that had the same composition as the photocurable compositions used in Examples 1 to 8 and Comparative Examples 1 and 2, except that they did not contain a crosslinking agent. The samples were irradiated with light under the conditions of the corresponding Examples and Comparative Examples. As a result, the monomer groups contained in the samples were polymerized to form a polymer. The Mw of this polymer was measured. The Mw was measured by GPC. The measuring device and measuring conditions were as follows. The measuring device and measuring conditions were different for the NVP-containing composition and the NVP-free composition.

(NVP-free composition)
Analytical equipment: Tosoh Corporation, HLC-8320GPC
Column: Tosoh Corporation, TSKgel GMH-H(S) x 2
Column size: 7.8 mm diameter x 30 cm, total 60 cm
Column temperature: 40°C
・Flow rate: 0.5mL/min
Injection volume: 100 μL
Eluent: Tetrahydrofuran Detector: Differential refractometer (RI)
・Standard sample: polystyrene

(NVP-containing composition)
Analytical equipment: Agilent Technologies, Agilent 1200
Column: Tosoh Corporation, TSKgel SuperAWM-H + superAW4000 + superAW2500
Column size: 6.0 mm diameter x 15 cm, total 45 cm
Column temperature: 40°C
・Flow rate: 0.4mL/min
Injection volume: 40 μL
Eluent: N,N-dimethylformamide (DMF)
Detector: differential refractometer (RI)
・Standard sample: polystyrene

<Gel Fraction>
The gel fraction of each of the pressure-sensitive adhesive sheets of the Examples and Comparative Examples was measured by the method described above.

<Polymerization rate of monomer group>
The polymerization rate of each of the pressure-sensitive adhesive sheets of the Examples and Comparative Examples was calculated from the change in weight of the pressure-sensitive adhesive sheet before and after 2 hours of heat drying at 130° C. Specifically, the weight of the pressure-sensitive adhesive sheet immediately after peeling off the base sheet and release liner was defined as _W0 (weight before drying), and the weight of the pressure-sensitive adhesive sheet after the heating and cooling at room temperature (23° C.) for about 20 minutes was defined as _W1 (weight after drying), and the polymerization rate was calculated using the formula: polymerization rate (%) = _W1 / _W0 × 100. Based on the calculated polymerization rate, the following judgments were made.
A: Polymerization rate of 98.5% or more B: Polymerization rate of 98.0% or more but less than 98.5% C: Polymerization rate of 97.5% or more but less than 98.0% D: Polymerization rate of less than 97.5%

<Reliability test>
(Preparation of Polarizing Film)
A polyvinyl alcohol film having a thickness of 80 μm was stretched to 3 times while being dyed for 1 minute in an iodine solution having a concentration of 0.3% at a temperature of 30° C. between rolls having different speed ratios. Next, the film was stretched to a total stretch ratio of 6 times while being immersed for 0.5 minutes in an aqueous solution having a temperature of 60° C. and containing boric acid at a concentration of 4% and potassium iodide at a concentration of 10%. Next, the film was immersed for 10 seconds in an aqueous solution having a temperature of 30° C. and containing potassium iodide at a concentration of 1.5% to wash, and then dried at 50° C. for 4 minutes to obtain a polarizer having a thickness of 28 μm. A transparent protective film having a thickness of 30 μm and made of a modified acrylic polymer having a lactone ring structure was attached to one side of the polarizer with a polyvinyl alcohol adhesive. Furthermore, a 47 μm-thick transparent protective film made of a triacetyl cellulose film (Konica Minolta, product name "KC4UY") with a hard coat layer (HC) was attached to the other surface of the polarizer using a polyvinyl alcohol adhesive. A polarizing film was produced by heating and drying for 5 minutes in an oven set at 70°C. Furthermore, a corona treatment was performed with a discharge amount of 63 W/ ^m2 ·min on the surface of the polarizing film on the transparent protective film side made of modified acrylic polymer.

(Preparation of polarizing film with adhesive sheet)
The above-mentioned polarizing film was placed on the exposed surface of each of the pressure-sensitive adhesive sheets prepared in the Examples and Comparative Examples to prepare a polarizing film with a pressure-sensitive adhesive sheet. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the pressure-sensitive adhesive sheet.

<Reliability test (85°C)>
The prepared polarizing film with adhesive sheet was evaluated for reliability (85°C reliability) by the following method. First, the polarizing film with adhesive sheet was cut into a strip of 228 mm length x 128 mm width to prepare a test piece. Next, the test piece was attached to the surface of alkali-free glass (manufactured by Corning, product name "EG-XG") with a thickness of 0.7 mm with an adhesive sheet. The test piece was attached to the alkali-free glass using a laminator. After the test piece was attached, it was placed in an autoclave at 50°C and 0.5 MPa for 15 minutes to homogenize the bonding between the alkali-free glass and the adhesive sheet, and the adhesive sheet was adhered to the alkali-free glass. Next, the test piece was subjected to a heat treatment at 85°C under atmospheric pressure for 500 hours. The vicinity of the end of the test piece was observed with an optical microscope to confirm the presence or absence of peeling from the end of the test piece and foaming near the end.
A: No peeling or foaming that would affect the image display was observed. B: Slight foaming at the edge, but not to the extent that would affect the image display. C: Multiple bubbles at the edge, but not to the extent that would affect the image display. D: Peeling and/or foaming that would affect the image display. E: Peeling and/or foaming that would significantly affect the image display.

<Reliability test (95°C)>
The 95° C. reliability was evaluated in the same manner as the 85° C. reliability, except that the temperature of the heat treatment was changed from 85° C. to 95° C. The evaluation items in categories A to E were the same as those in the 85° C. reliability.

<Adhesive slippage (85°C)>
The polarizing film with the adhesive sheet prepared in the reliability test evaluation was cut into a rectangular shape of 228 mm long x 128 mm wide to prepare a test sample. Next, the test sample was subjected to a heating test at 85°C for 500 hours, and the amount of the adhesive sheet protruding from the end face of the polarizing film was measured based on observation with an optical microscope using a 20x objective lens, and this was defined as the amount of adhesive slippage (85°C). For the observation, the transmitted light was set to 0 (zero) and adjustment was made so that only reflected light was observed.

The evaluation results are shown in Table 4 below. The polymerization rate is shown along with the evaluation results A to D.

As shown in Table 4, the adhesive sheet of the embodiment had a higher polymerization rate and improved reliability in high-temperature environments compared to the adhesive sheet of the comparative example.

The optical film with adhesive sheet of the present invention can be used in optical laminates and image display devices.

Reference Signs List 1: Adhesive sheet 2: Optical film 2A: Polarizing film 11: Optical film with adhesive sheet 30A, 30B, 30C: Optical laminate 31: Image display device

Claims (11)

The optical film is a photocurable adhesive sheet.
The pressure-sensitive adhesive sheet is an optical film with a pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet comprising a polymer having a structural unit derived from a nitrogen atom-containing monomer. The optical film with adhesive sheet according to claim 1, wherein the polymer is a (meth)acrylic polymer. The optical film with adhesive sheet according to claim 1, wherein the polymer further has a structural unit derived from a carboxyl group-containing monomer. The optical film with 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. The optical film with adhesive sheet according to claim 1, wherein the adhesive sheet contains a silane coupling agent. The optical film with adhesive sheet according to claim 1, wherein the thickness of the adhesive sheet is 30 μm or less. The optical film with adhesive sheet according to claim 1, wherein the solvent content in the adhesive sheet is 5% by weight or less. The optical film with adhesive sheet according to claim 1, wherein the adhesive sheet and the optical film are in contact with each other. The optical film with adhesive sheet according to claim 1, wherein the optical film is a polarizing film. An optical laminate comprising an optical film with a pressure-sensitive adhesive sheet according to any one of claims 1 to 9. An image display device comprising an optical film with a pressure-sensitive adhesive sheet according to any one of claims 1 to 9.

Images