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

Abstract

This invention provides an optical film with an adhesive sheet that is suitable for use in image display devices that may be exposed to high-temperature environments, while still featuring a light-curing adhesive sheet. [Solution] The provided optical film with an adhesive sheet comprises a photocurable adhesive sheet and an optical film. The gel fraction of the adhesive sheet is 55% or more and less than 94%. The content of sol A, which has a weight-average molecular weight of 100,000 or less, in the adhesive sheet is less than 6.6% by weight. The content of sol A may be 5.8% by weight or less, and even 4.9% by weight or less. The adhesive sheet may be acrylic.

Description

[Technical Field]

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

[0002] Various image display devices, such as liquid crystal displays and electroluminescent (EL) displays, generally include an optical laminate containing an optical film such as a polarizing film and an adhesive sheet. Adhesive sheets are typically used for bonding between optical films included in the optical laminate and for bonding the optical laminate to an image display panel. Typical adhesive sheets are sheets cured by polymerization and crosslinking of monomer groups, including acrylic monomers and silicone monomers. Patent Document 1 discloses a polarizing film with an adhesive sheet, comprising an adhesive sheet formed from a photocurable composition (hereinafter referred to as a photocurable adhesive sheet) and a polarizing film as the optical film. In addition to the photocurable type, there is also a thermosetting type of adhesive sheet, which is formed by curing a layer containing an adhesive composition and a solvent with heat. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-56510 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] When light-curing adhesive sheets are used in optical films with adhesive sheets, there is a tendency for image quality problems to occur in image display devices that may be exposed to high-temperature environments.

[0005] The present invention aims to provide an optical film with an adhesive sheet that is suitable for use in image display devices that may be exposed to high-temperature environments, while still being equipped with a photocurable adhesive sheet. [Means for solving the problem]

[0006] The present invention It comprises a light-curing adhesive sheet and an optical film, The gel fraction of the adhesive sheet is 55% or more and less than 94%. The content of sol component A with a weight-average molecular weight of 100,000 or less in the aforementioned adhesive sheet is less than 6.6% by weight. Optical film with adhesive sheet, To provide.

[0007] Furthermore, the present invention, An optical laminate is provided, comprising the above-mentioned optical film with an adhesive sheet.

[0008] Furthermore, the present invention, An image display device is provided, comprising the above-mentioned optical film with adhesive sheet. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an optical film with an adhesive sheet that is suitable for use in image display devices that may be exposed to high-temperature environments, even though it is equipped with a photocurable adhesive sheet. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view showing an example of an optical film with an adhesive sheet according to the present invention. [Figure 2] This is a schematic diagram illustrating an example of a method for forming an adhesive sheet that may be present in the optical film with an adhesive sheet of the present invention. [Figure 3] This is a schematic cross-sectional view showing an example of the optical laminate of the present invention. [Figure 4] This is a schematic cross-sectional view showing an example of the optical laminate of the present invention. [Figure 5] This is a schematic cross-sectional view showing an example of the optical laminate of the present invention. [Figure 6] This is a schematic cross-sectional view showing an example of the image display device of the present invention. [Figure 7]This graph shows the relationship between the gel fraction and the content of sol A (weight-average molecular weight of 100,000 or less) in each adhesive sheet of the examples and comparative examples. [Modes for carrying out the invention]

[0011] An optical film with an adhesive sheet according to the first aspect of the present invention is It comprises a light-curing adhesive sheet and an optical film, The gel fraction of the adhesive sheet is 55% or more and less than 94%. The content of sol component A with a weight-average molecular weight of 100,000 or less in the aforementioned adhesive sheet is less than 6.6% by weight.

[0012] In a second embodiment of the present invention, for example, in the optical film with an adhesive sheet according to the first embodiment, the content of the sol A is 5.8% by weight or less.

[0013] In a third embodiment of the present invention, for example, in the optical film with an adhesive sheet according to the first embodiment, the content of the sol A is 4.9% by weight or less.

[0014] In a fourth aspect of the present invention, for example, in an optical film with an adhesive sheet according to any one of the first to third aspects, the weight-average molecular weight of the polymer contained in the adhesive sheet is 700,000 or more and less than 800,000, and the weight-average molecular weight of all sol components B contained in the adhesive sheet is 600,000 or more, or the weight-average molecular weight of the polymer is 800,000 or more and the weight-average molecular weight of the sol components B is 450,000 or more.

[0015] In a fifth embodiment of the present invention, for example, in an optical film with an adhesive sheet according to any one of the first to fourth embodiments, the adhesive sheet comprises a (meth)acrylic polymer.

[0016] In a sixth embodiment of the present invention, for example, in an optical film with an adhesive sheet according to the fifth embodiment, the (meth)acrylic polymer has constituent units derived from a carboxyl group-containing monomer.

[0017] In a seventh embodiment of the present invention, for example, in an optical film with an adhesive sheet according to the fifth or sixth embodiment, the (meth)acrylic polymer has constituent units derived from nitrogen atom-containing monomers.

[0018] In the eighth aspect of the present invention, for example, in an optical film with an adhesive sheet according to any one of the first to seventh aspects, the adhesive sheet contains a silane coupling agent.

[0019] In the ninth aspect of the present invention, for example, in an optical film with an adhesive sheet according to any one of the first to eighth aspects, the thickness of the adhesive sheet is 50 μm or less.

[0020] In the tenth embodiment of the present invention, for example, in an optical film with an adhesive sheet according to any one of the first to ninth embodiments, the solvent content in the adhesive sheet is 5% by weight or less.

[0021] In the eleventh embodiment of the present invention, for example, in any one of the first to tenth embodiments, In an optical film with a light adhesive sheet, the adhesive sheet and the optical film are in contact.

[0022] In a twelfth aspect of the present invention, for example, in an optical film with an adhesive sheet according to any one of the first to eleventh aspects, the optical film is a polarizing film.

[0023] An optical laminate according to the thirteenth aspect of the present invention comprises an optical film with an adhesive sheet according to any one of the first to twelfth aspects.

[0024] An image display device according to the 14th aspect of the present invention comprises an optical film with an adhesive sheet according to any one of the first to 12 aspects.

[0025] The present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be modified and implemented as appropriate without departing from the spirit of the invention.

[0026] [Optical film with adhesive sheet] An example of an optical film with an adhesive sheet according to this embodiment is shown in Figure 1. The optical film with an adhesive sheet 11 in Figure 1 comprises an adhesive sheet 1 and an optical film 2. The adhesive sheet 1 and the optical film 2 are in contact with each other. The adhesive sheet 1 is a photocurable adhesive sheet formed from a photocurable composition. The gel fraction of the adhesive sheet 1 is 55% or more and 94% or less. The content of sol (sol A) with a weight-average molecular weight (hereinafter referred to as Mw) of 100,000 or less in the adhesive sheet 1 is less than 6.6% by weight. Note that the gel fraction is based on weight.

[0027] Our investigations have revealed that one of the factors contributing to the deterioration of image quality when exposed to high-temperature environments is that the adhesive sheet in the optical laminate and the adherend (object to which it is adhered) in contact with it become more prone to peeling at high temperatures. It is estimated that satisfying both the gel fraction and the sol content ranges for the adhesive sheet 1 contributes to balancing the stress relaxation characteristics and cohesive force of the adhesive sheet 1 to a state suitable for suppressing the peeling at high temperatures, and also helps to suppress the segregation of sol near the interface between the adhesive sheet 1 and the adherend. Furthermore, regions where sol, particularly sol A with an Mw of 100,000 or less, is segregated are considered to be relatively more susceptible to damage at high temperatures. An example of an adherend is a glass substrate.

[0028] The lower limit of the gel fraction of adhesive sheet 1 may be 56% or more, 57% or more, 58% or more, 59% or more, or even 60% or more. The upper limit of the gel fraction may be 93.5% or less, 93% or less, 92.5% or less, 92% or less, 91.5% or less, 91% or less, 90.5% or less, or even 90% or less.

[0029] The gel fraction of adhesive sheet 1 can be evaluated as follows. A test piece of approximately 0.1 g is taken from adhesive sheet 1, wrapped in a polytetrafluoroethylene porous sheet (average pore size 0.2 μm, trade name "NTF1122", manufactured by Nitto Denko Corporation), and then tied with kite string to obtain a measurement sample. Next, the weight of the obtained measurement sample (weight C before immersion) is measured. Weight C before immersion is the total weight of the test piece, polytetrafluoroethylene porous sheet, and kite string. Separately, the package weight B, which is the total weight of the polytetrafluoroethylene porous sheet and kite string, is measured. Next, the measurement sample is placed in a 50 mL container filled with ethyl acetate and left to stand at 23°C for 7 days. After standing, the measurement sample is removed from the container, transferred to an aluminum cup, and the ethyl acetate is removed by drying in a dryer at 130°C for 2 hours. The weight of the measurement sample after drying (weight A after immersion) is measured. The value calculated from the following formula is identified as the gel fraction of adhesive sheet 1. Gel fraction (%) = (AB) / (CB) × 100

[0030] The content of sol A in the adhesive sheet 1 may be 6.5% by weight or less, 6.3% by weight or less, 6.0% by weight or less, 5.8% by weight or less, 5.5% by weight or less, 5.3% by weight or less, 5.0% by weight or less, 4.9% by weight or less, 4.5% by weight or less, 4.3% by weight or less, 4.1% by weight or less, 4.0% by weight or less, 3.8% by weight or less, 3.7% by weight or less, 3.6% by weight or less, 3.5% by weight or less, 3.3% by weight or less, 3.0% by weight or less, 2.8% by weight or less, 2.5% by weight or less, 2.4% by weight or less, 2.3% by weight or less, 2.2% by weight or less, 2.1% by weight or less, and even 2.0% by weight or less. The lower limit of the content is not particularly limited and may be, for example, 0.0% by weight or more, 0.05% by weight or more, 0.1% by weight or more, and even 0.2% by weight or more.

[0031] In this specification, "sol component" refers to components that can be extracted from the adhesive sheet 1 using ethyl acetate. Sol component A refers to components with a Mw of 100,000 or less from the total sol component (sol component B) contained in the adhesive sheet 1. The content (weight %) of sol component B in the adhesive sheet 1 can be specified as 100 - gel fraction (%).

[0032] The content of sol component A in adhesive sheet 1 can be evaluated by gel permeation chromatography (GPC) as follows: A portion of adhesive sheet 1 is taken and dissolved in a GPC eluent to prepare a solution with a sol component concentration of approximately 2.0 g / L. A GPC eluent is selected that dissolves the sol component but does not substantially dissolve the gel component of adhesive sheet 1. The prepared solution is left overnight and then filtered through a 0.45 μm membrane filter. GPC measurement is performed on the filtrate to calculate the component ratio X of Mw 100,000 or less. The value calculated from the following formula can be identified as the content of sol component A in adhesive sheet 1. Content of sol A (weight %) = Content of sol B (weight %) × X / 100

[0033] The gel fraction and sol content of adhesive sheet 1 can vary depending, for example, on the composition of the photocurable composition used to form adhesive sheet 1 and the curing conditions of the photocurable composition. Examples of composition include the types and content of each monomer constituting the monomer group contained in the photocurable composition, the type and content of the photopolymerization initiator, and the type and content of the crosslinking agent. Examples of curing conditions include the integrated amount of light irradiated, the type of light source, the wavelength distribution, and the thickness of the coated film of the photocurable composition irradiated with light.

[0034] <Adhesive sheet> (Photocurable composition) The adhesive sheet 1 is formed from a photocurable composition. The photocurable composition usually contains monomers and / or partial polymers of the monomers. By irradiating the photocurable composition with light, polymers are generated from the monomers and / or partial polymers, and the adhesive sheet 1 is formed. The generated polymer is usually the main component of the adhesive sheet 1. The monomers may include (meth)acrylic monomers. The content of (meth)acrylic components in the photocurable composition, i.e., (meth)acrylic monomers and their partial polymers, 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 (meth)acrylic polymers can be formed. However, 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 main component means the component with the highest content. The content of the main component may be, for example, 50% by weight or more, and may also be 60% by weight or more, 70% by weight or more, or even 80% by weight or more.

[0035] Examples of (meth)acrylic monomers are alkyl (meth)acrylates having an alkyl group with 1 to 20 carbon atoms in 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. Good. Examples of alkyl (meth)acrylates include 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, and 2-ethylhexyl (meth)acrylate. These include lylate, 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 alkyl (meth)acrylate may also be n-butyl(meth)acrylate.

[0036] The content of alkyl (meth)acrylate 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. When calculating the content, the weight of the partially polymerized product is converted to the weight of each monomer before polymerization.

[0037] The monomer group may include carboxyl group-containing monomers. In this case, the (meth)acrylic polymer that the adhesive sheet 1 may contain has constituent units derived from carboxyl group-containing monomers. The carboxyl group-containing monomers may be (meth)acrylic monomers, in other words, (meth)acrylic monomers may contain carboxyl group-containing monomers. Examples of carboxyl group-containing monomers are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. The content of carboxyl group-containing monomers 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, and 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, and even 4.5% by weight or more. The monomer group does not have to contain carboxyl group-containing monomers.

[0038] The monomer group may include hydroxyl group-containing monomers. In this case, the (meth)acrylic polymer that the adhesive sheet 1 may contain has constituent units derived from hydroxyl group-containing monomers. The hydroxyl group-containing monomers may be (meth)acrylic monomers, in other words, (meth)acrylic monomers may contain hydroxyl group-containing monomers. Examples of hydroxyl group-containing monomers 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. Preferably, the hydroxyl group-containing monomers are 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate. The content of hydroxyl group-containing monomers in the monomer group may be, for example, 10% by weight or less, and may also 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 even 0.1% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, and may also be 0.03% by weight or more, and even 0.05% by weight or more. The monomer group may not contain hydroxyl group-containing monomers.

[0039] The monomer group may include nitrogen atom-containing monomers. In this case, the (meth)acrylic polymer that the adhesive sheet 1 may contain has constituent units derived from nitrogen atom-containing monomers. A nitrogen atom-containing monomer means a monomer that has at least one nitrogen atom in its molecule (in one molecule). In this specification, monomers having a hydroxyl group and a nitrogen atom in their molecule are classified as nitrogen atom-containing monomers. Monomers having a carboxyl group and a nitrogen atom in their molecule are classified as carboxyl group-containing monomers.

[0040] Preferred nitrogen atom-containing monomers include N-vinylcyclic amides and (meth)acrylamides. The nitrogen atom-containing monomers may be used individually or in combination of two or more types.

[0041] The N-vinyl cyclic amide is preferably represented by the following formula (A). [ka]

[0042] In equation (A), R 1 is a divalent organic group, preferably a divalent saturated hydrocarbon group or is an unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (for example, an alkylene group having 3 to 5 carbon atoms). Note that formula (A) is composed of N and R 1 They are directly bonded by a single bond. This indicates that a ring structure is formed.

[0043] The N-vinyl cyclic amide represented by formula (A) is preferably 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-morpholindione, more preferably N-vinyl-2-pyrrolidone and N-vinyl-2-caprolactam, and even more preferably N-vinyl-2-pyrrolidone.

[0044] Examples of (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, and N,N-dialkyl(meth)acrylamide. Examples of N-alkyl(meth)acrylamides include N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, Nn-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.

[0045] 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.

[0046] (Meth)acrylamides 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, and N-(3-hydroxypropyl)(meth)acrylamide. Examples include acrylic acid amide, N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, and N-methyl-N-2-hydroxyethyl(meth)acrylamide.

[0047] (Meth)acrylamides include, for example, various N-alkoxyalkyl(meth)acrylamides. Examples of N-alkoxyalkyl(meth)acrylamides include N-methoxymethyl(meth)acrylamide and N-butoxymethyl(meth)acrylamide.

[0048] Examples of nitrogen atom-containing monomers other than N-vinylcyclic amides and (meth)acrylamides include amino group-containing monomers such as (meth)aminoethyl acrylate, (meth)dimethylaminoethyl acrylate, (meth)dimethylaminopropyl acrylate, and (meth)t-butylaminoethyl 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, and N-methyl Examples include heterocyclic monomers such as vinylpyrrolidone; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimide 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 N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; and isocyanate group-containing monomers such as 2-(meth)acryloyloxyethyl isocyanate.

[0049] The nitrogen atom-containing monomer content in the monomer group may be, for example, 40% by weight or less, 35% by weight or less, or even 30% by weight or less. The lower limit of the content may be, for example, 5% by weight or more, 7% by weight or more, or even 10% by weight or more. The monomer group may not contain nitrogen atom-containing monomers.

[0050] The monomer group preferably includes carboxyl group-containing monomers and / or nitrogen atom-containing monomers, and more preferably both carboxyl group-containing monomers and nitrogen atom-containing monomers. When nitrogen atom-containing monomers, particularly both nitrogen atom-containing monomers and carboxyl group-containing monomers, are present in the photopolymerization system, there is a tendency for the molecular weight of the polymer to increase. This tendency may be due to the fact that the increase in viscosity of the polymerization system due to the formation of hydrogen bonds suppresses termination reactions between the growth ends of the polymer, making it easier for monomers to remain at the ends of the growth chains. The increase in the molecular weight of the polymer may contribute to an excellent balance of stress relaxation properties and cohesive force in the adhesive sheet 1. However, in thermosetting adhesive compositions, hydrogen bonding is less likely to occur because the monomers are dispersed in the solvent, and a large amount of radical chain transfer occurs in the solvent, so the above effect by nitrogen atom-containing monomers is not observed.

[0051] In the photocurable composition, each of the above-mentioned monomers may be included as a partial polymer. The partial polymer may be either a monopolymer or a copolymer. The photocurable composition does not need to contain a partial polymer.

[0052] Photocurable compositions typically contain a photopolymerization initiator. An example of a photopolymerization initiator is a photoradical generator that generates radicals upon irradiation with light. In a photopolymerization initiator, the absorption coefficient for light at a wavelength of 340 nm is, 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, but is, for example, 50 L / (g·cm) or less. The absorption coefficient of the photopolymerization initiator is calculated from the absorbance of a 0.01 mg / mL methanol solution measured using a visible-ultraviolet spectrophotometer with a quartz cell with a path length of 1 cm.

[0053] Examples of photopolymerization initiators include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzyldimethyl ketal; substituted benzoin ethers such as anisole methyl ether; substituted acetophenones such as 2,2-diethoxyacetophenone and 2,2-dimethoxy-2-phenylacetophenone; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, and 2,2'-dihydroxy-2 α-hydroxyalkylphenones such as 2'-dimethyl-1,1'-[methylenebis(4,1-phenylene)]bis(propan-1-one); substituted alpha ketoles such as 2-methyl-2-hydroxypropiophenone; aromatic sulfonyl chlorides such as 2-naphthalene sulfonyl chloride; photoactive oximes such as 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime; benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylic acid Benzophenone compounds such as benzoyl benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone; thioxanthone compounds such as thioxanthone, 2-chlorthioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and 2,4-diethylthioxanthone; 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, and 2-(p-methyl Xyphenyl)-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-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine Triazine compounds such as din and 2,4-trichloromethyl-(4'-methoxystyryl)-6-triazine; oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyl oxime)], and O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxynaphthyl)ethylidene)hydroxylamine; phosphine compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide;Quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone; borate compounds; carbazole compounds; imidazole compounds; and titanocene compounds. The photocurable composition may contain one or more photoinitiators. Note that α-hydroxyalkylphenone tends to have a large absorption of light with a wavelength of 340 ± 10 nm.;

[0054] Another example of a photoinitiator is a compound having the chemical structure shown in the following formula (1) (hereinafter referred to as chemical structure X) in the molecule.

Chemical formula

[0055] R in the formula (1) 1 and R 2 are, independently of each other, an alkyl group having 1 to 8 carbon atoms; -OH, an alkoxy group having 1 to 4 carbon atoms, -CN, -COOR 51 , -OOCR 52 , or an alkyl group having 1 to 4 carbon atoms in which a hydrogen atom is substituted by -NR 53 R 54 ; an alkenyl group having 3 to 6 carbon atoms; or -CH2-C6H4-R 55 . R 1 and R 2 may be bonded to each other to form an alkylene group having 2 to 9 carbon atoms, an oxyalkylene group having 3 to 6 carbon atoms, or an azaalkylene group. R 51 is an alkyl group having 1 to 8 carbon atoms. R 52 is an alkyl group having 1 to 4 carbon atoms. R 53 and R 54 are, independently of each other, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms; -OH, an alkoxy group having 1 to 4 carbon atoms, -CN, and -COOR 59 ; an alkyl group having 2 to 4 carbon atoms in which a hydrogen atom is substituted by at least one group selected from the group consisting of; an alkenyl group having 3 to 5 carbon atoms; or a cyclohexyl group. R 53 and R 54 are bonded to each other to form -O- or -N(R60 )- may be an alkylene group of C3-C9 which may be interrupted by R. 55 R is an alkyl group from C1 to C4. 59 R is an alkyl group from C1 to C4. 60 This includes a hydrogen atom, a C1-C4 alkyl group, an allyl group, a C1-C4 hydroxyalkyl group, and a -CH2CH2-COOR group. 61 Or it is -CH2CH2CN. 61 These are C1-C4 alkyl groups.

[0056] X is -OR 56 , or -NR 57 R 58 That is. R 56 is a hydrogen atom, -SiR 62 3, C1 It is an alkyl group of ~C8 or an alkenyl group of C3~C6. 57 and R 58 These are C1-C12 alkyl groups; -OH, C1-C4 alkoxy groups, -CN, and -COOR groups. 63 A C2-C4 alkyl group; a C3-C5 alkenyl group; or a cyclohexyl group, in which a hydrogen atom is substituted by at least one group selected from the group consisting of the following. 57 and R 58 These combine with each other to form -O- or -N(R 64 )- may be an alkylene group of C3-C9 which may be interrupted by R. 62 R is an alkyl group from C1 to C6. 63 R is an alkyl group from C1 to C4. 64 This includes a hydrogen atom, a C1-C4 alkyl group, an allyl group, a C1-C4 hydroxyalkyl group, and a -CH2CH2-COOR group. 65 Or it is -CH2CH2CN. 65 These are C1-C4 alkyl groups.

[0057] Chemical structure X can bond to a hydrogen atom or a hydrogen atom substitution structure via the carbon atom indicated by * in formula (1).

[0058] The alkyl groups, alkoxy groups, alkenyl groups, alkylene groups, oxyalkylene groups, azaalkylene groups, and hydroxyalkyl groups described in the description of formula (1) may be unbranched or branched. Furthermore, the notation "Cn1~Cn2" (where n1 and n2 are natural numbers) in this specification, including the description of formula (1), means that the number of carbon atoms is in the range of n1 to n2.

[0059] R 1 and R 2 These may be, independently of each other, C1-C8 alkyl groups or C3-C6 alkenyl groups, or they may be C1-C8 alkyl groups. 1 and R 2 These may be C1-C4 alkyl groups, C1-C3 alkyl groups, or C1-C2 alkyl groups, independently of each other. 1 and R 2 It may be a methyl group.

[0060] R 1 and R 2 They may be the same.

[0061] X is -OR 56 It is also acceptable. 56 X may be a hydrogen atom, or a C1-C8 alkyl group, or it may be a hydrogen atom. In other words, X may be -OH.

[0062] R 1 , R 2 And X can take any combination of the above preferred examples.

[0063] Chemical structure X may also be the structure shown in formula (2) below. In chemical structure X of formula (2), when a hydrogen atom substitution structure is bonded to the carbon atom indicated by *, the substitution structure and the -COCR in formula (2) 1 XR 2 A group is located in a para position relative to the benzene ring in chemical structure X. [ka]

[0064] The photopolymerization initiator may be a compound having two or more chemical structures X within a single molecule.

[0065] The photopolymerization initiator may be a compound shown in formula (3) below. The compound of formula (3) has two chemical structures X within one molecule. The two chemical structures X are located at opposite ends of the molecule of the photopolymerization initiator. More specifically, the two chemical structures X are bonded to each other by -A- at the carbon atoms of the phenylene group indicated by * above. [ka]

[0066] R in equation (3) 1 'and R 2 ' is mutual, and R 1 and R 2 Independently of R 1 and R 2 It is a possible group as R. 1 'and / or R 2 ' is R 1 and / or R 2 It may be the same as R. 1 , R 2 , R 1 'and R 2 ' may all be the same.

[0067] X' in equation (3) is a base that can be chosen as X independently of X in equation (1). X' and X may be the same.

[0068] A is -O-, -CYR 3 -, or -C(CH3)R 4 That is the case.

[0069] Y represents hydrogen, -Cl, -Br, -OR 71 , -NR 72 R 73 , or -SR 74 That is. R 3is a hydrogen atom, a C1-C8 alkyl group, a C3-C6 alkenyl group, benzyl group, -CH2-C6H4-R 75 , or a phenyl group. R 4 is a C1-C6 alkyl group or an alkylene group, and this alkylene group is bonded to the carbon atom of the phenylene group possessed by the compound of formula (3).

[0070] R 71 is a hydrogen atom, -Si(R 76 )3, a C1-C12 alkyl group, a C2-C18 a silyl group, -CO-NH-R 77 , a C2-C20 hydroxyalkyl group, a C2-C20 methoxyalkyl group, 3-R 78 -2-hydroxy-propyl group, 3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]-propyl group, 2,3-dihydroxy-propyl group, or a C2-C21 hydroxyalkyl group in which the carbon chain is interrupted by 1 to 9 oxygen atoms, or a C3-C25 alkyl group. R 72 and R 73 are each independently a C1-C12 alkyl group; -OH, a C1-C4 alkoxy group, -CN, and -COOR 79 a C2-C4 alkyl group in which a hydrogen atom is substituted by at least one group selected from the group consisting of; a C3-C5 alkenyl group; a cyclohexyl group; or a C7-C9 phenylalkyl group. R 72 and R 73 may be bonded to each other to form a C3-C9 alkylene group which may be interrupted by -O- or -N(R 80 )-. R 74 is a C1-C18 alkyl group, a hydroxyethyl group, a 2,3-dihydroxypropyl group, a cyclohexyl group, a benzyl group, a phenyl group, a C1-C12 alkylphenyl group, -CH2-COOR 81 -CH2CH2-COOR 82 , or -CH(CH3)-COOR 83 . R 75is an alkyl group of C1-C4. R 76 is an alkyl group of C1-C6. R 77 is an alkyl group of C1-C12. R 78 is an alkoxy group of C1-C18. R 79 is an alkyl group of C1-C4. R 80 is a hydrogen atom, an alkyl group of C1-C4, an allyl group, a benzyl group, a hydroxyalkyl group of C1-C4, -CH2CH2-COOR 84 or -CH2CH2CN. R 81 R 82 and R 83 are, independently of each other, an alkyl group of C1-C18. R 84 is an alkyl group of C1-C4.

[0071] In the description of formula (3), the alkyl group, alkenyl group, acyl group, hydroxyalkyl group, methoxyalkyl group, alkoxy group, and the alkyl group moiety in the phenylalkyl group, and the alkylene group may all be either unbranched or branched.

[0072] R in formula (3) 1 R 2 R 1 ’, and R 2 ’s preferred examples are the same as the preferred examples of R 1 and R 2 described above in the description of formula (1). The preferred examples of X’ in formula (3) are the same as the preferred examples of X described above in the description of formula (1). A may be -CYR 3 -. [[ID=…]] Y may be a hydrogen atom. R 3 may be a hydrogen atom. When A is -CYR … 3 - and both Y and R 3 may be hydrogen atoms. In other words, A may be -CH2-.

[0073] R in formula (3) 1 R 2 R 1 ’, R It should be noted that there seems to be some incomplete or unclear parts in the original text (such as the ellipsis in the middle). If you can provide more complete and accurate information, it will be helpful for a more accurate translation.2 ', X, X', A can be any combination of the above preferred examples.

[0074] The photopolymerization initiator may be a compound shown in formula (4) below. The compound of formula (4) is one of the compounds of formula (3). [ka]

[0075] 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). Note that the compound of formula (8) is derived from a vinyl compound having chemical structure X in its side chain. More specifically, it is an oligomer of the vinyl compound.

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] The photopolymerization initiators shown in formulas (5) to (9) are commercially available as Omnirad127, Esacure KIP160, Esacure one, Esacure KIP150, and Omnirad1173 (all manufactured by IGM Resins), respectively. The photopolymerization initiator may be at least one selected from this group.

[0082] Specific examples of photopolymerization initiators include 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 Omnirad184, Omnirad819, and Omnirad127, respectively (all manufactured by IGM Resin).

[0083] The amount of photopolymerization initiator in the photocurable composition is, for example, 20 parts by weight or less per 100 parts by weight of the monomer group and its partial polymers, 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 part 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, 0.2 parts by weight or less, 0.15 parts by weight or less, 0.1 parts by weight or less, and even 0.05 parts by weight or less. The lower limit of the amount is, for example, 0.01 parts by weight or more per 100 parts by weight of the monomer group and its partial polymers, and may be 0.03 parts by weight or more.

[0084] The photocurable composition may contain a crosslinking agent. An example of a 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. Examples of polyfunctional monomers 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 epoxy groups, aziridine groups, oxazoline groups, hydrazine groups, or methylol groups in one molecule. The polyfunctional monomer is preferably a monomer having two or more C=C bonds in one molecule.

[0085] Examples of polyfunctional monomers include (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. Polyfunctional acrylates such as hydrate, 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 (NDDA), 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, etc. (ester compounds of polyhydric alcohols and (meth)acrylic acid, etc.); allyl(meth)acrylate, vinyl(meth)acrylate, divinylbenzene, epoxyacrylate, 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, or dipentaerythritol hexa(meth)acrylate.

[0086] The amount of crosslinking agent used varies depending on the molecular weight, number of functional groups, etc., but is, for example, 5 parts by weight or less per 100 parts by weight of the monomer group and its partial polymers, and may 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, 0.15 parts by weight or less, 0.1 parts by weight or less, and even 0.05 parts by weight or less. The lower limit of the amount used is, for example, 0.01 parts by weight or more, and may be 0.03 parts by weight or more, and even 0.05 parts by weight or more. The photocurable composition may not contain a crosslinking agent.

[0087] 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 UV absorbers. The photocurable composition may also be free of additives.

[0088] 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-isocyanatetopropyltriethoxysilane.

[0089] The silane coupling agent may be an oligomeric type silane coupling agent. Oligomer-type silane coupling agents typically have multiple alkoxysilyl groups in a single 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. Oligomer-type silane coupling agents may have reactive functional groups. Examples of reactive functional groups include epoxy groups, mercapto groups, acid anhydride groups, and amino groups. Among these, those having epoxy groups are preferred, and those having multiple epoxy groups in a single molecule are more preferred. Examples of oligomeric silane coupling agents having epoxy groups are "X-41-1053", "X-41-1056", and "X-41-1059A" above. Examples of oligomeric silane coupling agents having mercapto groups are "X-41-1805", "X-41-1810", and "X-41-1818" above. An example of an oligomeric silane coupling agent having an acid anhydride group is "X-24-95" above. This is "91F". An example of an oligomeric silane coupling agent having an amino group is "X-40-2651" mentioned above.

[0090] The silane coupling agent may be an acetoacetyl group-containing silane coupling agent (for example, "A-100" manufactured by Soken Chemical Co., Ltd.).

[0091] If the photocurable composition contains a silane coupling agent, the amount of the silane coupling agent is, for example, 5 parts by weight or less per 100 parts by weight of the monomer group and its partial polymers, 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. The photocurable composition does not need to contain a silane coupling agent.

[0092] The viscosity of the photocurable composition is preferably 5 to 100 poise. Photocurable compositions having a viscosity within the above range are particularly suitable for forming adhesive sheets 1.

[0093] The solvent content in the photocurable composition may be, for example, 5% by weight or less, but may also 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 not contain substantially any solvent. Substantially solvent-free means that solvents derived from additives, etc., may be allowed 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. Furthermore, the solvent content in the adhesive sheet 1 may be within the above range. The adhesive sheet 1 may not contain substantially any solvent.

[0094] (Method of manufacturing adhesive sheets) The adhesive sheet 1 can be formed, for example, by irradiating a first laminate 20, which includes a base sheet 21, a coating layer 22 containing a photocurable composition, and a release liner 23 in that order, with light 24 (see Figure 2). The coating layer 22 hardens upon irradiation with light 24, becoming the adhesive sheet 1. Irradiation with light 24 is typically performed from the side of the base sheet 21. In this case, the light 24 penetrates 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 from both the release liner 23 and the base sheet 21.

[0095] 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, and constitutes part of the second laminate 27. By peeling the release liner 23 off the second laminate 27, a third laminate 25 is obtained, which includes the base sheet 21 and the adhesive sheet 1. In the third laminate 25, the surface of the adhesive sheet 1 is exposed to the outside. An optical film can be laminated to the exposed surface of the adhesive sheet 1, either directly or via another layer.

[0096] Light 24 is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light may include light with wavelengths in the same region as the absorption wavelength of the photopolymerization initiator contained in the photocurable composition. Light with short wavelengths of 300 nm or less cut off by a filter or the like may be used for irradiation, and cutting off short wavelengths is suitable for suppressing the deterioration of the substrate sheet 21 and / or peel liner 23 by light 24. The light source 28 of light 24 is, for example, a light irradiation device equipped with an ultraviolet irradiation lamp. Examples of ultraviolet irradiation lamps include ultraviolet LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-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 to be irradiated can be narrowed compared to when other light sources are used.

[0097] The light source 28 may be an LED. Compared to black light sources, LEDs not only allow for easier adjustment of illuminance but also tend to have a longer light source lifespan. Compared to black light sources that utilize mercury, LEDs are superior from the standpoint of reducing environmental impact. When using an ultraviolet light LED as the light source, an LED having a peak wavelength of 325-350 nm may be selected. According to the inventors' studies, using an LED having a peak wavelength of 325-350 nm may contribute to at least one of the following compared to using a black light source: an improvement in the polymerization rate of monomers in the adhesive sheet 1, an improvement in the molecular weight of the polymer, and a reduction in the amount of residual photopolymerization initiator. Furthermore, LEDs that emit light 14 with a peak wavelength of 325-350 nm tend to generate less heat and make it easier to control the temperature of the coated layer 22 compared to LEDs that emit light with a peak wavelength of approximately 365 nm. To the best of the inventors' knowledge, there have been no previous reports of adhesive sheets being made using LEDs that emit light with a peak wavelength of 325-350 nm.

[0098] As an LED with a peak wavelength of 325-350 nm, an LED with a peak wavelength of 340 ± 10 nm (hereinafter referred to as LED340) may be selected.

[0099] Focusing on the peak wavelength of light 24, the peak wavelength of light 24 irradiated onto the first laminate 20 (specifically the coated layer 22) may be 325 nm to 350 nm. The peak wavelength of light 24 is preferably 340 ± 10 nm (330 nm to 350 nm), but may also 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 is maximized in the spectrum showing the relationship between wavelength and intensity of light 24. Light 24 may further have peak wavelengths in wavelength ranges other than 325 nm to 350 nm, but it is preferable that it does not.

[0100] The illuminance of the light 24 irradiated onto the first laminate 20 (specifically the coated layer 22) is, for example, 2.0 to 30 mW / cm². 2 The illuminance is 2.5 mW / cm². 2 More than 3.0mW / cm 2 The above 3 0.5 mW / cm 2 More than 4.0mW / cm 2 More than 5.0mW / cm 2 Above, 6.0mW / cm 2 More than 7.0mW / cm 2 More than 8.0mW / cm 2 More than 9.0mW / cm 2 Furthermore, 10 mW / cm² 2 It may be greater than or equal to this. The upper limit of illuminance is, for example, 25 mW / cm². 2 The following is true: 20 mW / cm² 2 Furthermore, 15 mW / cm² 2 The following is also acceptable.

[0101] The time for irradiating the first laminate 20 (specifically the coated layer 22) with light 24 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 light 24 may be continuous or intermittent.

[0102] The integrated amount of light 24 on the first laminate 20 (specifically the coated layer 22) is, for example, 25 mJ / cm². 2 That is all, 100 mJ / cm 2 More than 250mJ / cm 2 More than 500mJ / cm 2 More than 750mJ / cm 2 More than 850mJ / cm 2 More than 1000mJ / cm 2 More than 1250mJ / cm 2 Furthermore, 1500 mJ / cm 2 The above is also acceptable. The upper limit of the integrated light intensity is not particularly limited, for example, 5000 mJ / cm². 2 The following applies, 4000mJ / cm 2 Below, 3000mJ / cm 2 Below, 2500mJ / cm 2 Below, 2000mJ / cm 2 Furthermore, 1750 mJ / cm² 2 The following is also acceptable.

[0103] An example of the base material of the release liner 23 (hereinafter referred to as "liner base material") is a resin film. Examples of resins that may be included in the liner base material are polyethylene terephthalate and polyethylene nitrate. These include polyesters such as phthalates, acetate resins, polyethersulfones, polycarbonates, polyamides, polyimides, polyolefins, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

[0104] The peel-off liner 23 may include layers other than the liner substrate. The peel-off liner 23 may include a release layer. For example, the peel-off liner 23 comprises a liner substrate and a release layer formed on one side of the liner substrate. This peel-off liner 23 can be used such that the release layer is on the side of the coating layer 22. The release layer is typically a cured layer of a release agent composition containing a release agent. Various release agents can be used, 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.

[0105] The release liner 23 may be in the form of a single sheet or a long strip.

[0106] An example of the base sheet 21 is a resin film. An example of the resin contained in the base sheet 21 is the same as an example of the resin that may be contained in the liner base material.

[0107] The thickness of the base sheet 21 is, for example, 10 to 200 μm, and may be 25 to 150 μm.

[0108] The base sheet 21 may have a release layer on the side facing the coating layer 22. Examples of release layers that the base sheet 21 may have are the same as examples of release layers that the release liner 23 may have. Both the release liner 23 and the base sheet 21 may have release layers.

[0109] For the base sheet 21, it is usually possible to select a sheet with a greater peeling force from the adhesive sheet 1 compared to the peeling liner 23.

[0110] The base sheet 21 may be in the form of a single leaf or a long length.

[0111] The first laminate 20 can be formed, for example, by forming a coating layer 22 on a base sheet 21 (or 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 may be formed by pouring a photocurable composition into the space between the base sheet 21 and the release liner 23, which are held at a predetermined distance apart so that their main surfaces face each other.

[0112] Various coating methods can be applied to form the coated 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.

[0113] The thickness of the coating layer 22 can be adjusted according to the desired thickness of the adhesive sheet 1, for example, 5 to 100 μm, but may also be 5 to 50 μm, 5 to 25 μm, or even 5 to 20 μm.

[0114] The first laminate 20 may include a long base sheet 21, a long coating layer 22, and a long release liner 23; in other words, it may be long. The long first laminate 20 can be obtained, for example, by conveying the base sheet 21 and the release liner 23 unwound from a winding body and forming the coating layer 22 between them.

[0115] The Mw of the polymer contained in adhesive sheet 1 is, for example, 500,000 or more, 550,000 or more, 60 It may be 10,000 or more, 650,000 or more, 700,000 or more, over 700,000, 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 even 1,400,000 or more. The upper limit of Mw is not particularly limited, for example, 3,000,000 or less. The Mw of the polymer and the Mw of sol component B are measured by GPC (gel permeation chromatography) and determined from the value calculated in polystyrene equivalent.

[0116] The Mw of sol component B contained in the adhesive sheet 1 is, for example, 300,000 or more, and may be 350,000 or more, 400,000 or more, 450,000 or more, 500,000 or more, 550,000 or more, 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, and even 1,000,000 or more. The upper limit of Mw is not particularly limited, for example, 3,000,000 or less.

[0117] In adhesive sheet 1, (I) the Mw of the polymer may be 700,000 or more and less than 800,000, and the Mw of sol component B may be 600,000 or more. Alternatively, in adhesive sheet 1, (II) the Mw of the polymer may be 800,000 or more, and the Mw of sol component B may be 450,000 or more. Adhesive sheet 1 that satisfies condition (I) or (II) is particularly suitable for suppressing peeling of the adhesive sheet 1 from the adherend at high temperatures. The adherend is, for example, a glass substrate.

[0118] 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, and even 20 μm or less. The lower limit of the thickness may be 5 μm or more, 10 μm or more, and even 15 μm or more. Even when the thickness of the adhesive sheet 1 is, for example, 30 μm or less, it is suitable for suppressing foaming and peeling from the adherend in high-temperature environments.

[0119] <Optical film> Examples of optical film 2 include polarizing films, phase difference films, and laminated films comprising polarizing films and / or phase difference films. However, optical film 2 is not limited to the above examples. Optical film 2 may also include glass films.

[0120] The optical film 2 is a polarizing film, and the adhesive sheet 1 may be in contact with the polarizing film. Polarizing films tend to undergo significant dimensional changes due to heat compared to other optical films. Dimensional changes in the polarizing film can cause delamination from the adhesive film. Therefore, the present invention is particularly advantageous when the optical laminate further comprises a polarizing film.

[0121] A polarizing film includes a polarizer. Typically, a polarizing film includes a polarizer and a protective film (a transparent protective film). The protective film is, for example, positioned in contact with the main surface (the surface with the largest area) of the polarizer. The polarizer may be positioned between two protective films. The protective film may be positioned on at least one surface of the polarizer.

[0122] The polarizer is not particularly limited and includes, for example, hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and partially saponified ethylene-vinyl acetate copolymer films, on which dichroic substances such as iodine and dichroic dyes are adsorbed and then uniaxially stretched; and polyene-based oriented films such as dehydrated polyvinyl alcohol products and dehydrochlorinated polyvinyl chloride products. Typically, the polarizer consists of a polyvinyl alcohol-based film (polyvinyl alcohol-based films include partially saponified ethylene-vinyl acetate copolymer films) and a dichroic substance such as iodine.

[0123] The thickness of the polarizer is not particularly limited, and may be, for example, 80 μm or less, but may also be 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, but may also be 5 μm or more, 10 μm or more, or even 15 μm The thickness may be greater than m. Thin polarizers (for example, less than 20 μm thick) have suppressed dimensional changes and can contribute to improving the durability of optical laminates, especially their durability at high temperatures.

[0124] As the material for the protective film, for example, a thermoplastic resin that is excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc., can be used. Specific examples of such thermoplastic resins include cellulose resins such as triacetylcellulose, polyester resins, polyethersulfone 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. The material for the protective film may also be a thermosetting resin or an ultraviolet-curable resin such as (meth)acrylic, urethane, acrylic-urethane, epoxy, or silicone-based resin. If the polarizing film has two protective films, the materials of the two protective films may be the same or different. For example, a protective film made of a thermoplastic resin may be bonded to one main surface of the polarizer via an adhesive, and a protective film made of a thermosetting resin or an ultraviolet-curable resin may be bonded to the other main surface of the polarizer. The protective film may contain one or more additives. Examples of additives include UV absorbers, antioxidants, lubricants, plasticizers, mold release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0125] The thickness of the protective film can be determined as appropriate, but generally it is around 5 to 200 μm, considering factors such as strength, ease of handling, and thinness.

[0126] The polarizer and protective film are typically bonded together via a water-based adhesive. Examples of water-based adhesives include isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex, water-based polyurethane, and water-based polyester. Other adhesives besides those mentioned above include UV-curing adhesives and electron beam-curing adhesives. Electron beam-curing adhesives for polarizing films exhibit suitable adhesion to various protective films. The adhesive may also contain metal compound fillers.

[0127] In polarizing films, a phase difference film or the like can be formed on the polarizer instead of a protective film. Furthermore, another protective film, a phase difference film, or the like can be added on top of the protective film.

[0128] Regarding the protective film, a hard coat layer may be provided on the surface that is in contact with the polarizer and the surface facing it, and treatments for purposes such as anti-reflection, anti-sticking, diffusion, and anti-glare may be applied.

[0129] The polarizing film may also be a circularly polarizing film.

[0130] The thickness of the polarizing film is, for example, 500 μm or less, but may also 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, but may also be 25 μm or more, or even 40 μm or more.

[0131] A phase difference film is a film that exhibits birefringence in the in-plane direction and / or in the thickness direction. Examples of phase difference films include stretched resin films and films in which liquid crystal materials are oriented and immobilized.

[0132] Phase difference films include λ / 4 plates, λ / 2 plates, anti-reflective phase difference films (see, for example, paragraphs 0221, 0222, and 0228 of Japanese Patent Publication No. 2012-133303), and viewing angle compensation phase difference films (see, for example, paragraphs 0225 and 0226 of Japanese Patent Publication No. 2012-133303). ), or a tilted orientation phase difference film for viewing angle compensation (see, for example, paragraph 0227 of Japanese Patent 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 in the thickness direction. The phase difference value, arrangement angle, three-dimensional birefringence, whether it is single-layer or multi-layer, etc. of the phase difference film are also not limited. Known films can be used as the phase difference film.

[0133] The thickness of optical film 2 is, for example, 1 to 200 μm.

[0134] The optical film 2 may be a single layer or a laminated film composed of two or more layers. If the optical film 2 is a laminated film, an adhesive sheet 1 may be used to bond each layer.

[0135] The adhesive sheet-attached optical film 11 may include other layers besides the adhesive sheet 1 and the optical film 2. Other layers may be placed 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.

[0136] The adhesive optical film 11 can be used, for example, in optical laminates and image display devices. However, the applications of the adhesive optical film 11 are not limited to the examples above.

[0137] [Optical laminate] An example of the optical laminate of this embodiment is shown in Figure 3. The optical laminate 30A in Figure 3 comprises the adhesive sheet-attached optical film 11 of this embodiment. The optical laminate 30A has a laminated structure in which a release liner 3, an adhesive sheet 1, and an optical film 2 are laminated in this order. The optical laminate 30A can be used as an adhesive sheet-attached optical film 11 by peeling off the release liner 3.

[0138] The release liner 3 is typically a resin film. Examples of resins that make up the release liner 3 include polyester 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 treated with a release agent. The release agent is, for example, treated with a silicone compound. However, the release liner 3 is not limited to the above examples. 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.

[0139] Another example of the optical laminate of this embodiment is shown in Figure 4. The optical laminate 30B in Figure 4 includes the optical film 11 with adhesive sheet of this embodiment. The optical laminate 30B has a laminated structure in which a release liner 3, an adhesive sheet 4, a phase difference film 2B, an adhesive sheet 1, and a polarizing film 2A are laminated in this order. 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.

[0140] Any known adhesive sheet can be used for adhesive sheet 4. Adhesive sheet 1 may also be used for adhesive sheet 4.

[0141] Another example of the optical laminate of this embodiment is shown in Figure 5. The optical laminate 30C in Figure 5 includes the optical film 11 with adhesive sheet of this embodiment. The optical laminate 30C has a laminated structure in which a release liner 3, an adhesive sheet 4, a phase difference film 2B, an adhesive sheet 1, a polarizing film 2A, and a protective film 5 are laminated in this order. 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.

[0142] The protective film 5 protects the optical laminate 30C during distribution and storage, and also protects the optical laminate 30C. When incorporated into an image display device, the protective film 5 has the function of protecting the outermost optical film 2 (polarizing film 2A). Alternatively, when incorporated into an image display device, the protective film 5 may function as a window to the outside space. 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, with polyester being preferred. 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 treatments such as anti-glare, anti-reflective, and anti-static properties.

[0143] The protective film 5 may be bonded to the optical film 2 with any adhesive. Bonding with an adhesive sheet 1 is also possible.

[0144] The optical laminate of this embodiment may include any layer other than the layer described above. The optical laminate of this embodiment can have any configuration as long as it includes an optical film 11 with an adhesive sheet.

[0145] The optical laminate of this embodiment can be distributed and stored, for example, as a wound body formed by winding a strip-shaped optical laminate, or as a single-sheet optical laminate.

[0146] The optical laminate of this embodiment is typically used in image display devices. These image display devices are, for example, EL displays such as liquid crystal displays, organic EL displays, and inorganic EL displays.

[0147] [Image display device] An example of an image display device of this embodiment is shown in Figure 6. The image display device 31 in Figure 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 phase difference 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 optical film 11 with an adhesive sheet shown in Figure 1, and the optical laminates 30A, 30B, and 30C shown in Figures 3 to 5 (excluding the release liner 3). The substrate 7 and the image forming layer 6 may have the same configuration as the substrate and image forming layer of a known image display device.

[0148] The image display device 31 in Figure 6 may be an organic EL display or a liquid crystal display. However, the image display device 31 is not limited to these examples. The image display device 31 may be an electroluminescent (EL) display, a plasma display (PD), a field emission display (FED), etc. The image display device 31 may be used for home appliance applications, automotive applications, public information display (PID) applications, etc.

[0149] The image display device 31 can have any configuration as long as it includes an optical film 11 with an adhesive sheet and / or the optical laminate of this embodiment. [Examples]

[0150] 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.

[0151] [Preparation of photocurable compositions] (Monomer Syrup A1) n-butyl acrylate (BA) 95.1 parts by weight, 4-hydroxybutyl acrylate 0.1 parts by weight of (HBA), 4.8 parts by weight of acrylic acid (AA), and 0.05 parts by weight of Omnirad 184 (manufactured by IGM Resin) as a photopolymerization initiator were placed in a four-necked flask. Next, the liquid in the flask was irradiated with ultraviolet light under a nitrogen atmosphere to obtain monomer syrup A1, in which monomers were partially photopolymerized. The ultraviolet 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) reached 20 Pa·s.

[0152] (Potential syrups A2~A6) Monomer syrups A2 to A6 were prepared by the same method as monomer syrup A1, except that the monomers and photopolymerization initiators were changed as shown in Table 1.

[0153] [Table 1]

[0154] The abbreviations used in Table 1 are as follows: BA: n-butyl acrylate HBA: 4-hydroxybutyl acrylate AA: Acrylic acid Omnirad184: 1-Hydroxycyclohexyl phenyl ketone (Omnirad184, manufactured by IGM Resin). Omnirad819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad819, manufactured by IGM Resins) Omnirad127: 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)2-methylpropan-1-one (Omnirad127, manufactured by IGM Resin)

[0155] (Photocurable compositions C1 to C29) Next, monomer syrup, monomers, crosslinking agents, and silane coupling agents were mixed to obtain photocurable compositions C1 to C29, with the compositions shown in Table 2 below.

[0156] [Table 2]

[0157] The abbreviations used 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 Silicone Co., Ltd., product name "KBM-403") X-41-1056: Epoxy group-containing oligomer-type silane coupling agent (manufactured by Shin-Etsu Silicone Co., Ltd., product name "X-41-1056")

[0158] The final monomer compositions contained in each photocurable composition are shown in Table 3 below.

[0159] [Table 3]

[0160] [Making adhesive sheets] <Example 1> (Preparation of release liner) A silicone-based mold release agent composition was obtained by mixing 30 parts by weight of addition-curing silicone (LTC761 containing a hexenyl group-containing polyorganosiloxane, 30% by weight toluene solution, 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), 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 diluent. The concentration of silicone solids in the mold release agent composition was 1.0% by weight. Next, the mold release agent composition was applied to one side of a liner substrate (Lumirror XD500P polyester film, 75 μm thick) using a wire bar, and heated at 130°C for 1 minute to produce a release liner with a release layer (60 nm thick) on one side.

[0161] (Making adhesive sheets) A monomer syrup C1 was applied to one side of a base sheet (PET separator, manufactured by Mitsubishi Plastics, MRF38) using an applicator to form a coating layer (20 μm thick). Next, a release liner was placed on the formed coating layer to obtain the first laminate. The release liner is... The mold layer was positioned in contact with the coating layer. Next, from the side of the substrate sheet in the first laminate, an illuminance of 3.5 mW / cm was applied. 2 And under the condition of irradiation time of 460 seconds (integrated light intensity of 1600 mJ / cm²). 2 Light was irradiated using an LED. The peak wavelength of the irradiated light was 340 nm. As a result, the coated layer was photocured, and an adhesive sheet (20 μm thick) of Example 1 was obtained, sandwiched between a substrate sheet and a release liner. The illuminance was measured using an illuminance meter (Topcon Techno House, UD-T3040T2) at a position near the incident surface of ultraviolet light on the substrate sheet.

[0162] <Examples 2-24, Comparative Examples 1-6> Adhesive sheets for Examples 2-24 and Comparative Examples 1-6 were obtained by the same method as in Example 1, except that the photocurable composition used and the light irradiation conditions were changed as shown in Table 4. Regarding the light source, "LED" refers to the LED used in Example 1, and "BL+LED" refers to a combination of a black light source and the LED used in Example 1. In the case of "BL+LED," the integrated light quantity is the sum of the integrated light quantities from both light sources. The irradiation conditions for each light source in the case of "BL+LED" were as follows. BL: Illuminance 6.2mW / cm 2 And under the condition of irradiation time of 95 seconds (integrated light intensity 589 mJ / cm²) 2 ) LED: Illuminance 3.1mW / cm 2 And under the condition of irradiation time of 90 seconds (integrated light amount 279 mJ / c m 2 )

[0163] [Evaluation Method] <Mw of polymer> Samples were prepared having the same composition as the photocurable compositions used in Examples 1-24 and Comparative Examples 1-6, 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 monomers contained in the samples polymerized, forming polymers. The Mw of these polymers was measured. Mw was measured by GPC. The measurement equipment and conditions were as follows. Note that the measurement equipment and conditions differed for NVP-containing compositions and NVP-free compositions.

[0164] (NVP-free composition) • Analytical instrument: Tosoh Corporation, HLC-8320GPC • Column: Tosoh Corporation, TSKgel GMH-H(S) x 2 • Column size: 7.8mmφ x 30cm each, total 60cm Column temperature: 40°C ·Flow rate: 0.5mL / min ·Injection volume: 100μL • Eluent: Tetrahydrofuran • Detector: Differential refractometer (RI) • Standard sample: Polystyrene

[0165] (NVP-containing composition) • Analytical instrument: Agilent Technologies, Agilent 1200 • Column: Tosoh Corporation, TSKgel SuperAWM-H+superAW4000+ superAW2500 • Column size: 6.0mmφ x 15cm each, total 45cm Column temperature: 40°C ·Flow rate: 0.4mL / min ·Injection volume: 40μL • Eluent: N,N-dimethylformamide (DMF) • Detector: Differential refractometer (RI) • Standard sample: Polystyrene

[0166] <Content of sol component A> The content of sol component A in each adhesive sheet of the examples and comparative examples was measured using the above method with GPC. The GPC measuring device and measurement conditions were as follows. Note that the measuring device and measurement conditions differed for NVP-containing compositions and NVP-free compositions.

[0167] (NVP-free composition) • Analytical instrument: Tosoh Corporation, HLC-8320GPC • Column: Tosoh Corporation, TSKgel GMH-H(S) x 2 • Column size: 7.8mmφ x 30cm each, total 60cm Column temperature: 40°C ·Flow rate: 0.5mL / min ·Injection volume: 100μL • Eluent: Tetrahydrofuran • Detector: Differential refractometer (RI) • Standard sample: Polystyrene

[0168] (NVP-containing composition) • Analytical instrument: Agilent Technologies, Agilent 1200 • Column: Tosoh Corporation, TSKgel SuperAWM-H+superAW4000+ superAW2500 • Column size: 6.0mmφ x 15cm each, total 45cm Column temperature: 40°C ·Flow rate: 0.4mL / min ·Injection volume: 40μL • Eluent: N,N-dimethylformamide (DMF) • Detector: Differential refractometer (RI) • Standard sample: Polystyrene

[0169] <Mw of sol component B> The Mw of sol component B in each adhesive sheet of the examples and comparative examples was determined by the same GPC measurement used to evaluate the content of sol component A.

[0170] [Gel fraction] The gel fraction of each adhesive sheet in the examples and comparative examples was measured by the method described above.

[0171] (Reliability testing) <Preparation of polarizing film> An 80 μm thick polyvinyl alcohol film was stretched to 3 times its original size while being stained for 1 minute in a 0.3% iodine solution at 30°C between rolls with different speed ratios. Next, it was stretched to a total stretch ratio of 6 times while being immersed for 0.5 minutes in an aqueous solution at 60°C containing 4% boric acid and 10% potassium iodide. Then, after being washed by immersion for 10 seconds in an aqueous solution at 30°C containing 1.5% potassium iodide, a polarizer with a thickness of 28 μm was obtained by drying at 50°C for 4 minutes. A 30 μm thick transparent protective film made of a modified acrylic polymer having a lactone ring structure was laminated to one side of the polarizer using a polyvinyl alcohol-based adhesive. Furthermore, a 47 μm thick transparent protective film, consisting of a triacetylcellulose film (manufactured by Konica Minolta, product name "KC4UY") with a hard coat layer (HC) formed on it, was laminated to the other side of the polarizer using a polyvinyl alcohol-based adhesive. It was then heated and dried in an oven set to 70°C for 5 minutes. A polarizing film was fabricated by this method. Furthermore, a discharge rate of 63 W / m was applied to the surface of the polarizing film on the transparent protective film side, which is made of a modified acrylic polymer. 2 ·min Corona treatment He carried out the rationale.

[0172] <Preparation of polarizing film with adhesive sheet> A polarizing film with an adhesive sheet was prepared by placing the above-mentioned polarizing film on the exposed surface of each adhesive sheet prepared in the examples and comparative examples. The polarizing film was positioned so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.

[0173] <Reliability Test (85°C)> For the polarizing film with the produced adhesive sheet, the reliability (85 °C reliability) was evaluated by the following method. First, the polarizing film with the adhesive sheet was cut into a strip shape with a length of 228 mm and a width of 128 mm to obtain a test piece. Next, the test piece was attached to the surface of non-alkali glass (manufactured by Corning, product name "EG-XG") with a thickness of 0.7 mm using the adhesive sheet. The attachment of the test piece to the non-alkali glass was performed using a laminator. After attaching the test piece, it was placed in an autoclave at 50 °C and 0.5 MPa for 15 minutes to homogenize the bonding between the non-alkali glass and the adhesive sheet, and the adhesive sheet was adhered to the non-alkali glass. Next, the test piece was heat-treated at 85 °C for 500 hours under atmospheric pressure. 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 in the vicinity of the end. A: No peeling and foaming that affect image display are confirmed B: There is slight foaming at the end, but it is not at a level that affects image display C: There are multiple bubbles at the end, but it is not at a level that affects image display D: There is peeling and / or foaming that affects image display E: There is peeling and / or foaming that significantly affects image display

[0174] <Reliability test (95 °C)> The 95 °C reliability was evaluated by the same method as the 85 °C reliability, except that the heat treatment temperature was changed from 85 °C to 95 °C. The classification A - E of the evaluation items was the same as that of the 85 °C reliability.

[0175] The evaluation results are shown in Table 4 below. Also, the relationship between the gel fraction and the content of sol A in each adhesive sheet of the examples and comparative examples is shown in Figure 7.

[0176]

Table 4

[0177] As shown in Table 4, in the adhesive sheet of the example, the reliability in a high-temperature environment could be improved as compared with the adhesive sheet of the comparative example.

Industrial Applicability

[0178] The optical film with an adhesive sheet of the present invention can be used for an optical laminate and an image display device.

Explanation of Signs

[0179] 1 Adhesive sheet 2 Optical film 2A Polarizing film 11 Optical film with an adhesive sheet 30A, 30B, 30C Optical laminate 31 Image display device

Claims

1. It comprises a light-curing adhesive sheet and an optical film, The gel fraction of the adhesive sheet is 55% or more and less than 94%. The content of sol component A with a weight-average molecular weight of 100,000 or less in the aforementioned adhesive sheet is less than 6.6% by weight. Optical film with adhesive backing.

2. The optical film with an adhesive sheet according to claim 1, wherein the content of the sol component A is 5.8% by weight or less.

3. The optical film with an adhesive sheet according to claim 1, wherein the content of the sol component A is 4.9% by weight or less.

4. The weight-average molecular weight of the polymer contained in the adhesive sheet is 700,000 or more and less than 800,000, and the weight-average molecular weight of all sol components B contained in the adhesive sheet is 600,000 or more, or The weight-average molecular weight of the polymer is 800,000 or more, and the weight-average molecular weight of the sol component B is 450,000 or more. The optical film with an adhesive sheet as described in claim 1.

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

6. The optical film with an adhesive sheet according to claim 5, wherein the (meth)acrylic polymer has constituent units derived from a carboxyl group-containing monomer.

7. The optical film with an adhesive sheet according to claim 5, wherein the (meth)acrylic polymer has constituent units derived from nitrogen atom-containing monomers.

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

9. The optical film with an adhesive sheet according to claim 1, wherein the thickness of the adhesive sheet is 50 μm or less.

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

11. The optical film with an adhesive sheet according to claim 1, wherein the adhesive sheet and the optical film are in contact.

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

13. An optical laminate comprising an optical film with an adhesive sheet as described in any one of claims 1 to 12.

14. An image display device comprising an optical film with an adhesive sheet according to any one of claims 1 to 12.

Images