Optical laminates and image display devices

Abstract

To provide an optical laminate with good antistatic properties. [Solution] An optical laminate comprising an optical film, an antistatic layer and an adhesive layer in this order, wherein the adhesive layer comprises a (meth)acrylic resin (A), a crosslinking agent (B), a silane compound (C), and an antistatic agent (D), and the antistatic agent (D) comprises an ionic compound consisting of an imidazolium cation and a thiocyano group-containing anion.

Description

[Technical Field]

[0001] This invention relates to an optical laminate and an image display device. [Background technology]

[0002] Polarizing plates are widely used in image display devices such as liquid crystal displays. Polarizing plates are bonded to adjacent components such as liquid crystal cells and touch input elements via an adhesive layer. Therefore, an adhesive layer is often pre-laminated on one surface of the polarizing plate before bonding it to the liquid crystal cell, and in this case, a separator film is usually temporarily attached to protect the exposed surface of the adhesive layer. This separator film is peeled off immediately before bonding the polarizing plate, but peeling often causes the adhesive layer to become electrostatically charged. Static electricity is also generated when peeling off the surface protection film (e.g., cover window) that protects the surface of the polarizing plate attached to the liquid crystal cell or touch input element. This generated static electricity can disrupt the orientation of liquid crystal molecules in the liquid crystal layer inside the liquid crystal display device, which can lead to display performance problems.

[0003] To suppress the generation of such static electricity, for example, Patent Document 1 describes an optical laminate in which an antistatic function is provided to the adhesive layer, and an antistatic layer having antistatic properties is provided between the adhesive layer with the antistatic properties and the polarizing plate. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2014-160246 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, even with the optical laminate described in Patent Document 1, there were cases where the antistatic performance was insufficient. In particular, when the optical laminate is used in vehicle applications, higher antistatic performance is required to prevent malfunctions.

[0006] Therefore, the present invention aims to provide an optical laminate having good antistatic performance, and an image display device using the same. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides the following optical laminate and image display device. [1] An optical laminate comprising an optical film, an antistatic layer and an adhesive layer in this order, wherein the adhesive layer comprises a (meth)acrylic resin (A), a crosslinking agent (B), a silane compound (C), and an antistatic agent (D), and the antistatic agent (D) comprises an ionic compound consisting of an imidazolium cation and a thiocyano group-containing anion. [2] The optical laminate according to [1] above, wherein the (meth)acrylic resin (A) contains structural units derived from alkoxyalkyl (meth)acrylate. [3] The optical laminate according to [1] or [2] above, wherein the antistatic layer comprises at least one selected from the group consisting of conductive polymers, conductive fine particles, and carbon nanotubes. [4] The optical laminate according to any one of [1] to [3] above, wherein the optical film comprises a first resin film and a hard coat layer disposed on the antistatic layer side of the first resin film. [5] The optical laminate according to any one of [1] to [4] above, wherein the optical film comprises a first resin film and a polarizer disposed on the opposite side of the first resin film from the antistatic layer. [6] The moisture permeability of the first resin film described above is 350 g / m² at a temperature of 40°C and a relative humidity of 90%. 2 The optical laminate described in [4] or [5] above, wherein the time interval is 24 hours or less. [7] The optical film has a retardation layer disposed between the first resin film and the polarizer, and the water vapor permeability of the laminate of the first resin film and the retardation layer is 350 g / m at a temperature of 40° C. and a relative humidity of 90% 2 / 24 hr or less, the optical layered product according to any one of [4] to [6] above. [8] The optical layered product according to any one of [4] to [7] above, wherein the optical film has a second resin film disposed on a side of the polarizer opposite to the first resin film. [9] An image display device comprising the optical layered product according to any one of [1] to [8] above. Effects of the Invention

[0008] According to the present invention, an optical layered product having good antistatic performance and an image display device using the same can be provided. Further, the optical layered product of the present invention can also have good metal corrosion resistance. Brief Description of Drawings

[0009] [Figure 1] It is a schematic cross-sectional view showing one embodiment of the optical layered product of the present invention. Mode for Carrying Out the Invention

[0010] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[0011] [Optical Layered Product] The optical laminate of the present invention comprises an optical film, an antistatic layer, and an adhesive layer in that order, wherein the adhesive layer contains a (meth)acrylic resin (A), a crosslinking agent (B), a silane compound (C), and an antistatic agent (D), and the antistatic agent (D) contains an ionic compound consisting of an imidazolium cation and a thiocyano group-containing anion. The optical laminate of the present invention can have good antistatic performance. The reason for this effect is not entirely clear, but it is presumed that by comprising an adhesive layer containing the above-mentioned specific components and an antistatic layer, the antistatic agent (D) is dispersed to a certain extent uniformly in the adhesive layer, making the antistatic layer and the adhesive layer more conductive, and thus lowering the surface resistance value of the surface of the adhesive layer.

[0012] Figure 1 shows a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention. The optical laminate 100 shown in Figure 1 has, in this order, an adhesive layer 1, an antistatic layer 2, a hard coat layer 3, a first resin film 4, a phase difference layer 5, a first bonding layer 6, a polarizer 7, a second bonding layer 8, and a second resin film 9. The polarizer 7 is protected by a first protective layer 10 consisting of a hard coat layer 3, a first resin film 4, and a phase difference layer 5, which is bonded to one surface of the polarizer 7 via the first bonding layer 6, and a second protective layer consisting of a second resin film 9, which is bonded to the surface of the polarizer 7 opposite to the first protective layer 10 via the second bonding layer 8. The polarizer 7, the first and second bonding layers 6 and 8, and the first and second protective layers 10 and 9 form a polarizing plate 20. In the optical laminate 100, the polarizing plate 20 corresponds to an optical film. Furthermore, a separator film may be provided on the surface of the adhesive layer 1 opposite to the antistatic layer 2. The following describes each layer that constitutes the optical laminate 100.

[0013] <Adhesive layer 1> The adhesive layer contains a (meth)acrylic resin (A), a crosslinking agent (B), a silane compound (C), and an antistatic agent (D). The antistatic agent (D) also contains an ionic compound consisting of an imidazolium cation and a thiocyano group-containing anion. The adhesive layer can be formed using an adhesive composition containing the above components. The components constituting the adhesive layer will be described below. In this specification, (meth)acrylic means either acrylic or methacrylic, and (meth)acrylate means either acrylate or methacrylate.

[0014] ((Meth)acrylic resin (A)) The (meth)acrylic resin (A) may contain structural units derived from (meth)acrylates such as alkyl (meth)acrylates and alkoxyalkyl (meth)acrylates, and structural units derived from monomers having polar groups. From the viewpoint of compatibility of ionic compounds consisting of an imidazolium cation and a thiocyano group-containing anion with the (meth)acrylic resin (A), it is preferable that the (meth)acrylic resin (A) is a highly hydrophilic (meth)acrylic resin (A), and it is preferable that it contains structural units derived from alkoxyalkyl (meth)acrylates.

[0015] Examples of alkyl (meth)acrylates include alkyl (meth)acrylate (a) (hereinafter also referred to as "alkyl (meth)acrylate (a)"), which has a homopolymer glass transition temperature (hereinafter also referred to as "Tg") of less than 0°C, and alkyl (meth)acrylate (b) (hereinafter also referred to as "alkyl (meth)acrylate (b)"), which has a homopolymer glass transition temperature of 0°C or higher.

[0016] The Tg of the alkyl (meth)acrylate homopolymers (a) and (b) can be determined using literature values ​​such as those found in the POLYMER HANDBOOK (Wiley-Interscience).

[0017] Specific examples of alkyl (meth)acrylate (a) include linear or branched alkyl acrylates with 2 to 12 carbon atoms in the alkyl group, such as ethyl acrylate, n- and i-propyl acrylate, n- and i-butyl acrylate, n-pentyl acrylate, n- and i-hexyl acrylate, n-heptyl acrylate, n- and i-octyl acrylate, 2-ethylhexyl acrylate, n- and i-nonyl acrylate, n- and i-decyl acrylate, and n-dodecyl acrylate; and linear or branched alkyl methacrylates with 4 to 12 carbon atoms in the alkyl group, such as n-pentyl methacrylate, n- and i-hexyl methacrylate, n-heptyl methacrylate, n- and i-octyl methacrylate, 2-ethylhexyl methacrylate, n- and i-nonyl methacrylate, n-decyl methacrylate, and n-dodecyl methacrylate. Alkyl (meth)acrylate (a) may be an alkyl (meth)acrylate (cycloalkyl (meth)acrylate) having an alicyclic structure, but from the viewpoint of conformability to the optical film (or flexibility and tackiness), it is preferably an alkyl acrylate having 2 to 10 carbon atoms, more preferably an alkyl acrylate having 3 to 8 carbon atoms, and even more preferably an alkyl acrylate having 4 to 6 carbon atoms. Alkyl (meth)acrylate (a) may be used alone or in combination of two or more types.

[0018] Specific examples of alkyl(meth)acrylate(b) include methyl acrylate, methyl methacrylate, stearyl acrylate, tert-butyl acrylate, ethyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, propyl methacrylate, isopropyl methacrylate, etc. Alkyl(meth)acrylate(b) may also be an alkyl(meth)acrylate (cycloalkyl(meth)acrylate) having an alicyclic structure. The alicyclic structure can be a cycloparaffin structure with a carbon number of 5 or more, preferably 5 to 7. Specific examples of alkyl (meth)acrylates having an alicyclic structure include isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, trimethylcyclohexyl methacrylate, tert-butylcyclohexyl methacrylate, 1-adamantyl methacrylate, isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, and α-ethoxyacrylate cyclohexyl. Alkyl (meth)acrylate (b) may be used alone or in combination of two or more types.

[0019] The content of alkyl (meth)acrylate-derived structural units is preferably 0.5 to 90 parts by mass, more preferably 1.0 to 70 parts by mass, and even more preferably 1.0 to 60 parts by mass, per 100 parts by mass of all structural units constituting the (meth)acrylic resin (A).

[0020] Examples of alkoxyalkyl (meth)acrylates include 2-methoxymethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. Alkoxyalkyl (meth)acrylates may be used individually or in combination of two or more types.

[0021] From the viewpoint of compatibility between the antistatic agent (D) and the (meth)acrylic resin (A), the content of structural units derived from alkoxyalkyl (meth)acrylate is preferably 10 parts by mass or more and 99 parts by mass or less, more preferably 20 parts by mass or more and 99 parts by mass or less, and even more preferably 40 parts by mass or more and 98 parts by mass or less, per 100 parts by mass of all structural units constituting the (meth)acrylic resin (A).

[0022] A monomer having a polar group can be an ethylenically unsaturated monomer having one or more polar groups in its molecular chain. Examples of monomers having a polar group include monomers having a hydroxyl group, monomers having a carboxyl group, and monomers having a nitrogen atom. A monomer having a polar group may be used alone or in combination of two or more.

[0023] Examples of monomers containing a hydroxyl group include hydroxyl group-containing (meth)acrylates. Specific examples of hydroxyl group-containing (meth)acrylates include 1-hydroxymethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, 1-hydroxyheptyl (meth)acrylate, 1-hydroxybutyl (meth)acrylate, 1-hydroxypentyl (meth)acrylate, and other 1-hydroxy C1-C8 alkyl (meth)acrylates; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, 2-hydroxyhexyl (meth)acrylate, and other 2-hydroxy C2-C9 alkyl (meth)acrylates; and 3-hydroxypropyl (meth)acrylate and 3-hydroxybutyl (meth)acrylate. Examples include 3-hydroxy C3-C10 alkyl (meth)acrylates such as acrylate, 3-hydroxypentyl (meth)acrylate, 3-hydroxyhexyl (meth)acrylate, and 3-hydroxyheptyl (meth)acrylate; 4-hydroxy C4-C11 alkyl (meth)acrylates such as 4-hydroxybutyl (meth)acrylate, 4-hydroxypentyl (meth)acrylate, 4-hydroxyhexyl (meth)acrylate, 4-hydroxyheptyl (meth)acrylate, and 4-hydroxyoctyl (meth)acrylate; and 2-chloro-2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate. From the viewpoint of mechanical strength and heat resistance, the monomer having a hydroxyl group is preferably 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-hydroxypentyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate.

[0024] When the (meth)acrylic resin (A) contains structural units derived from hydroxyl group-containing (meth)acrylate, the content of structural units derived from hydroxyl group-containing (meth)acrylate is preferably 0.1 to 5.5 parts by mass, more preferably 0.1 to 4.0 parts by mass, and even more preferably 0.3 to 2.5 parts by mass, per 100 parts by mass of all structural units constituting the (meth)acrylic resin (A), from the viewpoint of mechanical strength and heat resistance.

[0025] Specific examples of monomers having a carboxyl group (hereinafter also referred to as "carboxyl group-containing monomers") include (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and carboxyalkyl (meth)acrylates (e.g., carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate). Acrylic acid is preferred among these. A single monomer having a carboxyl group may be used alone, or two or more may be used in combination.

[0026] When the (meth)acrylic resin (A) contains structural units derived from monomers having carboxyl groups, the content of structural units derived from carboxyl group monomers may be 0.1 parts by mass or more and 5.5 parts by mass or less per 100 parts by mass of all structural units constituting the (meth)acrylic resin (A), and is preferably 0.1 parts by mass or more and 4 parts by mass or less, and more preferably 0.2 parts by mass or more and 2.5 parts by mass or less, from the viewpoint of mechanical strength and heat resistance durability.

[0027] Examples of monomers containing nitrogen atoms include amino group-containing monomers, amide group-containing monomers, and other nitrogen atom-containing monomers. A single nitrogen atom-containing monomer may be used alone, or two or more may be used in combination.

[0028] Examples of amino group-containing monomers include primary amino group-containing monomers such as aminomethyl (meth)acrylate and aminoethyl (meth)acrylate; secondary amino group-containing monomers such as t-butylaminoethyl (meth)acrylate; and tertiary amino group-containing monomers such as ethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate. Furthermore, from the viewpoint of preventing a decrease in the release properties of the separator film that can be laminated onto the adhesive layer, it is preferable that the material substantially contains no structural units derived from monomers having amino groups. "Substantially contained" means less than 1.0 part by mass per 100 parts by mass of all structural units constituting the (meth)acrylic resin (A).

[0029] Examples of amide group-containing monomers include (meth)acrylamide; alkoxyalkyl (meth)acrylamide monomers such as methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, propoxymethyl (meth)acrylamide, isopropoxymethyl (meth)acrylamide, n-butoxymethyl (meth)acrylamide, and isobutoxymethyl (meth)acrylamide; hydroxyl group-containing amide monomers such as N-(hydroxymethyl)acrylamide; dialkyl (meth)acrylamide monomers such as dimethyl (meth)acrylamide and diethyl (meth)acrylamide; and heterocyclic amide monomers such as (meth)acryloylmorpholine.

[0030] The (meth)acrylic resin (A) may further contain structural units derived from styrene monomers, structural units derived from vinyl monomers, structural units derived from monomers having multiple (meth)acryloyl groups in the molecule, and the like.

[0031] Examples of styrene monomers include styrene; alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, and octylstyrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene.

[0032] Examples of vinyl monomers include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; vinylidenes such as vinylidene chloride; nitrogen-containing aromatic vinyls such as vinylpyridine, vinylpyrrolidone, and vinylcarbazole; and conjugated diene monomers such as butadiene, isoprene, and chloroprene.

[0033] Examples of monomers having multiple (meth)acryloyl groups in their molecule include monomers having two (meth)acryloyl groups in their molecule, such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; and monomers having three (meth)acryloyl groups in their molecule, such as trimethylolpropane tri(meth)acrylate.

[0034] The weight-average molecular weight (Mw) of the (meth)acrylic resin (A) is preferably 1 million to 2 million, more preferably 1.1 million to 1.9 million, even more preferably 1.2 million to 1.8 million, and particularly preferably 1.3 million to 1.7 million, from the viewpoint of mechanical strength and heat resistance. The molecular weight distribution (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the (meth)acrylic resin (A), may be, for example, 1.5 to 10, preferably less than 3.5, and more preferably 2.5 to less than 3.5, from the viewpoint of mechanical strength and heat resistance. The weight-average molecular weight can be analyzed by gel permeation chromatography (GPC) and is a value on a standard polystyrene basis.

[0035] The glass transition temperature of the (meth)acrylic resin (A) is preferably -65°C to -10°C, more preferably -60°C to -15°C, and even more preferably -55°C to -30°C, from the viewpoint of mechanical strength and dispersibility of the antistatic agent (D).

[0036] (Meth)acrylic resin (A) (or a mixture thereof if two or more types are combined) is preferably prepared by dissolving it in ethyl acetate and adjusting the concentration to 20% by mass. The resulting solution exhibits a viscosity of 1.0 Pa·s to 30 Pa·s, and more preferably 3.0 Pa·s to 20 Pa·s, at 25°C. The viscosity can be measured using a Brookfield viscometer.

[0037] (Meth)acrylic resin (A) can be produced by known methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. A polymerization initiator is usually used in the production of (meth)acrylic resin (A). The polymerization initiator is used in amounts of approximately 0.001 to 5 parts by mass per 100 parts by mass of all monomers used in the production of (meth)acrylic resin (A). Alternatively, (meth)acrylic resin (A) may be produced by a method in which polymerization is carried out using active energy rays such as ultraviolet light.

[0038] As polymerization initiators, thermal polymerization initiators and photopolymerization initiators are used. Examples of photopolymerization initiators include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone. Examples of thermal polymerization initiators include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonnitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), and 2,2'-azobis(2-hydroxymethylpropionitrile); lauryl peroxane. Examples of organic peroxides include tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl) peroxide; and inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. In addition, redox initiators using peroxides and reducing agents can also be used as polymerization initiators.

[0039] As a method for producing (meth)acrylic resin (A), the solution polymerization method is preferred among the methods described above. An example of the solution polymerization method involves mixing monomers and an organic solvent, adding a thermal polymerization initiator under a nitrogen atmosphere, and stirring at approximately 40 to 90°C, preferably 50 to 80°C, for approximately 3 to 48 hours. To control the reaction, monomers and thermal polymerization initiators may be added continuously or intermittently during polymerization, or added in a dissolved state in the organic solvent. Examples of organic solvents that can be used include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0040] (Crosslinking agent (B)) The crosslinking agent (B) can be a compound that reacts with structural units derived particularly from polar functional group-containing monomers in the (meth)acrylic resin (A) to crosslink the (meth)acrylic resin (A). Specifically, examples include isocyanate compounds, epoxy compounds, aziridine compounds, and metal chelate compounds. Of these, isocyanate compounds, epoxy compounds, and aziridine compounds are preferably compounds that have at least two functional groups in their molecule that can react with polar functional groups in the (meth)acrylic resin. The crosslinking agent (B) may be used alone or in combination of two or more types.

[0041] Preferred isocyanate compounds are those having at least two isocyanate groups (-NCO) in the molecule. Examples include aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate), alicyclic isocyanate compounds (e.g., isophorone diisocyanate), and aromatic isocyanate compounds (e.g., tolylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.). Furthermore, the crosslinking agent (B) may also be a derivative of a urethane prepolymer-type isocyanate compound obtained by addition reaction with an isocyanate compound or an adduct (e.g., an adduct with glycerol, trimethylolpropane, etc.), an isocyanurate, a burette-type compound, a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc. The crosslinking agent (B) can be used alone or in combination of two or more. Among these, typical examples include aromatic isocyanate compounds (e.g., tolylene diisocyanate, xylylene diisocyanate), aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate), or adducts thereof with polyhydric alcohol compounds (glycerol, trimethylolpropane). When the crosslinking agent (B) contains an aromatic isocyanate compound and / or an adduct thereof with polyhydric alcohol compounds, it tends to easily improve mechanical strength and heat resistance.

[0042] The epoxy compound is preferably a compound having at least two epoxy groups in its molecule. Specific examples of such compounds include bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N-diglycidylaniline, N,N,N',N'-tetraglycidyl-m-xylenediamine, and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane. Two or more epoxy compounds can also be used in combination.

[0043] Aziridine compounds are preferably compounds that have at least two three-membered ring skeletons consisting of one nitrogen atom and two carbon atoms, also known as ethyleneimines, within their molecule. Specific examples of such compounds include diphenylmethane-4,4'-bis(1-aziridinecarboxamide), toluene-2,4-bis(1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1-(2-methylaziridine), tris-1-aziridinylphosphine oxide, hexamethylene-1,6-bis(1-aziridinecarboxamide), trimethylolpropane-tris-β-aziridinylpropionate, and tetramethylolmethane-tris-β-aziridinylpropionate.

[0044] Examples of metal chelate compounds include compounds in which acetylacetone or ethyl acetoethyl is coordinated to polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium.

[0045] Preferably, the compounds are isocyanate compounds, and more preferably aromatic isocyanate compounds, such as tolylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and their polyhydric alcohol compounds (e.g., glycerol, trimethylolpropane, etc.).

[0046] The crosslinking agent (B) content is preferably 0.2 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.5 parts by mass or more and 2.0 parts by mass or less, per 100 parts by mass of solid content of (meth)acrylic resin (A) (total if two or more types are used), from the viewpoint of mechanical strength and heat resistance durability.

[0047] (Silane compound (C)) The adhesive composition contains a silane compound (C). By including the silane compound (C), the adhesion (or bonding) between the adhesive layer and the metal layer, transparent electrode, glass substrate, etc. can be improved. Examples of silane compounds (C) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 1,3-bis(3'-trimethoxypropyl)urea, 1,6-bis(trimethoxysilyl)hexane, and 1,8-bis(trimethoxysilyl)octane.

[0048] The silane compound may also be a silicone oligomer. Specific examples of silicone oligomers are shown below. In the following examples, the silicone oligomer is expressed as a combination of monomers.

[0049] 3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomer, and other mercaptopropyl group-containing oligomers.

[0050] Mercaptomethyl group-containing oligomers such as mercaptomethyltrimethoxysilane-tetramethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, and mercaptomethyltriethoxysilane-tetraethoxysilane oligomer.

[0051] 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer, etc., containing a methacryloyloxypropyl group.

[0052] Acryloyloxypropyl group-containing oligomers such as 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer.

[0053] Vinyl group-containing oligomers such as vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, and vinylmethyldiethoxysilane-tetraethoxysilane oligomer.

[0054] The content of silane compound (C) is usually 0.01 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the solid content of (meth)acrylic resin (A) (total if two or more types are used), preferably 0.1 parts by mass or more and 4 parts by mass or less, and more preferably 0.2 parts by mass or more and 3 parts by mass or less, from the viewpoint of mechanical strength and heat resistance durability. Silane compound (C) may be used alone or in combination of two or more types.

[0055] (Antistatic agent (D)) The adhesive composition of the present invention contains an antistatic agent (D). By incorporating the antistatic agent (D) into the adhesive layer, the adhesive layer can be given antistatic properties. The antistatic agent (D) contains an ionic compound consisting of an imidazolium cation and a thiocyano group-containing anion. Because the ionic compound has a highly polar thiocyano group-containing anion, it is easier to trap iodine in polarizers that has been released by humidity and heat in a humid and hot environment. Therefore, it is possible to suppress the transfer of iodine to liquid crystal cells, touch panel input elements, etc., and durability and metal corrosion resistance in a humid and hot environment tend to improve. Furthermore, because the ionic compound has good compatibility with (meth)acrylic resin (A), the transfer of the ionic compound itself can also be suppressed, and durability and metal corrosion resistance tend to improve.

[0056] The molecular weight of the imidazolium cation is preferably 400 or less, more preferably 350 or less, even more preferably 320 or less, even more preferably 300 or less, particularly preferably 280 or less, and preferably 80 or more. When the molecular weight of the imidazolium cation is 400 or less, its compatibility with the (meth)acrylic resin (A) is increased, and the antistatic performance is more easily improved. Furthermore, when the molecular weight is 80 or above a certain molecular weight, it is possible to suppress the uneven distribution of the antistatic agent on the side of the adhesive layer that is bonded to the image display device, making it easier to maintain a uniformly dispersed state of the antistatic agent and suppressing metal corrosion, etc.

[0057] Examples of imidazolium cations include 1,3-dimethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-methyl-3-propylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-methyl-3-pentylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-heptyl-3-methylimidazolium cation, 1-methyl-3-octylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-hexadecyl-3-methylimidazolium, and 1-ethyl Examples include dialkylimidazolium cations such as -3-propylimidazolium cation and 1-butyl-3-ethylimidazolium cation; and trialkylimidazolium cations such as 3-ethyl-1,2-dimethylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1,2-dimethyl-3-hexylimidazolium cation, 1,2-dimethyl-3-octylimidazolium cation, 1-ethyl-3,4-dimethylimidazolium cation, and 1-isopropyl-2,3-dimethylimidazolium cation. From the viewpoint of compatibility with (meth)acrylic resin (A), dimethylimidazolium cation is preferred, and 1-ethyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-methyl-3-octylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, and 1-hexadecyl-3-methylimidazolium are more preferred.

[0058] Examples of thiocyano group-containing anions include thiocyanate anions or anions represented by the following formula (1). [ka] (In the formula, X represents one element selected from the group consisting of boron, carbon, nitrogen, aluminum, silicon, phosphorus, arsenic, and selenium. Y represents a hydrogen atom, an alkyl group, or a trifluoromethyl group. L represents an organic linking group. a is an integer greater than or equal to 1, and b and c are integers greater than or equal to 0. However, since the valence of the anion is -1, when the valence of element X is x, the values ​​of a and c are determined such that the relationship x-1=(a+c) is satisfied.)

[0059] In formula (1), Y represents a hydrogen atom, an alkyl group, or a trifluoromethyl group. The alkyl group is preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably a methyl group or an ethyl group. Y is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0060] In formula (1), L is preferably -S-, -O-, -SO2-, or -CO-.

[0061] The thiocyano group-containing anion is preferably a thiocyanate anion from the viewpoint of compatibility with (meth)acrylic resin (A) or dispersibility in the adhesive composition.

[0062] Examples of ionic compounds include 1,3-dimethylimidazolium thiocyanate, 1-ethyl-3-methylimidazolium thiocyanate, 1-methyl-3-propylimidazolium thiocyanate, 1-butyl-3-methylimidazolium thiocyanate, 1-methyl-3-pentylimidazolium thiocyanate, 1-hexyl-3-methylimidazolium thiocyanate, 1-heptyl-3-methylimidazolium thiocyanate, 1-methyl-3-octylimidazolium thiocyanate, 1-decyl-3-methylimidazolium thiocyanate, 1-dodecyl-3-methylimidazolium thiocyanate, 1-hexadecyl-3-methylimidazolium thiocyanate, and 1-ethyl- Examples include dialkylimidazolium cation thiocyanates such as 3-propylimidazolium thiocyanate and 1-butyl-3-ethylimidazolium thiocyanate; and trialkylimidazolium thiocyanates such as 3-ethyl-1,2-dimethylimidazolium thiocyanate, 1,2-dimethyl-3-propylimidazolium thiocyanate, 1-butyl-2,3-dimethylimidazolium thiocyanate, 1,2-dimethyl-3-hexylimidazolium thiocyanate, 1,2-dimethyl-3-octylimidazolium thiocyanate, 1-ethyl-3,4-dimethylimidazolium thiocyanate, and 1-isopropyl-2,3-dimethylimidazolium thiocyanate. Ionic compounds may be used individually or in combination of two or more.

[0063] The antistatic agent (D) may contain antistatic agents other than ionic compounds consisting of an imidazolium cation and a thiocyano group-containing anion. From the viewpoint of further improving antistatic performance and metal corrosion resistance, the content of the ionic compound consisting of an imidazolium cation and a thiocyano group-containing anion in the antistatic agent (D) is preferably 50% by mass or more, more preferably 80% by mass or more, and may be 100% by mass, based on the total amount of the antistatic agent (D).

[0064] The content of the antistatic agent (D) may be 0.1 to 20 parts by mass relative to 100 parts by mass of the (meth)acrylic resin (A), from the viewpoints of improving antistatic performance and suppressing bleeding out. It is preferably 0.5 to 15 parts by mass, more preferably 1.0 to 10 parts by mass, and still more preferably 3.5 to 10 parts by mass.

[0065] The thickness of the pressure-sensitive adhesive layer may be, for example, 10 µm or more and 50 µm or less. From the viewpoints of mechanical strength and heat resistance durability, it is preferably 15 µm or more and 40 µm or less, more preferably 18 µm or more and 35 µm or less. When the thickness of the pressure-sensitive adhesive layer is 10 µm or more, a decrease in adhesiveness can be suppressed, so the possibility of causing durability defects can be reduced. When the thickness is 50 µm or less, the occurrence of defects such as the end face of the pressure-sensitive adhesive layer adhering to a cutting blade and detaching during cutting of the optical laminate can be suppressed.

[0066] From the viewpoint of antistatic performance, the surface resistance value of a single film of the pressure-sensitive adhesive layer is 9.0×10 10 Ω / □ or less, preferably 5.0×10 10 Ω / □ or less, more preferably 9.0×10 9 Ω / □ or less, still more preferably 5.0×10 9 Ω / □ or less, particularly preferably. Further, the surface resistance value of a single film of the pressure-sensitive adhesive layer is 1.0×10 4 Ω / □ or more, preferably 1.0×10 5 Ω / □ or more, more preferably 1.0×10 6 Ω / □ or more, still more preferably.

[0067] From the viewpoint of antistatic performance, the surface resistance value of the pressure-sensitive adhesive layer measured in the state of the optical laminate is 1.0×10 8 less than Ω / □, preferably 8.0×10 7 Ω / □ or less, more preferably 6.0×10 7 Ω / □ or less, still more preferably. Further, the surface resistance value of the pressure-sensitive adhesive layer measured in the state of the optical laminate is 1.0×10 4It is preferable that the ratio be Ω / □ or greater, and 1.0 × 10 5 It is more preferable that the ratio is Ω / □ or greater, and 1.0 × 10 6 It is even more preferable that the ratio is Ω / □ or greater.

[0068] <Antistatic layer 2> The antistatic layer 2 includes materials that can impart antistatic properties, such as conductive polymers, conductive fine particles, and carbon nanotubes (hereinafter sometimes referred to as CNTs). The antistatic layer 2 can be formed from a composition containing the above-mentioned antistatic materials, and can be formed by coating the above composition onto an optical film (preferably a polarizing plate) and drying it.

[0069] Examples of conductive fine particles include metal oxides such as tin oxide, antimony oxide, indium oxide, and zinc oxide, with tin oxide being preferred. Examples of tin oxide include tin oxide, antimony-doped tin oxide, indium-doped tin oxide, aluminum-doped tin oxide, tungsten-doped tin oxide, titanium oxide-cerium oxide-tin oxide composites, and titanium oxide-tin oxide composites. The average particle size of the fine particles is usually 1 to 100 nm, and preferably 2 to 50 nm.

[0070] Examples of conductive polymers include polyaniline, polythiophene, polypyrrole, and polyquinoxaline, with water-soluble conductive polymers such as polyaniline and polythiophene, or water-dispersible conductive polymers, being preferred. Water-soluble conductive polymers or water-dispersible conductive polymers allow the coating solution for forming the antistatic layer to be prepared as an aqueous solution or aqueous dispersion. This eliminates the need for non-aqueous organic solvents, thus suppressing deterioration of optical films such as polarizers due to these organic solvents. The aqueous solution or aqueous dispersion may contain water-based solvents in addition to water. Examples of water-based solvents include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert-butanol.

[0071] Water-soluble conductive polymers or water-dispersible conductive polymers such as polyaniline and polythiophene preferably have hydrophilic functional groups in their molecules. Examples of hydrophilic functional groups include sulfone groups, amino groups, amide groups, imino groups, quaternary ammonium bases, hydroxyl groups, mercapto groups, hydrazino groups, carboxyl groups, sulfate ester groups, phosphate ester groups, or salts thereof. Having hydrophilic functional groups in the molecule makes the polymer more soluble in water or more easily dispersed in water as fine particles, allowing for the easy preparation of water-soluble conductive polymers or water-dispersible conductive polymers.

[0072] Examples of commercially available water-soluble conductive polymers include polyaniline sulfonic acid (manufactured by Mitsubishi Chemical Corporation, weight-average molecular weight 150,000 in polystyrene equivalent). Examples of commercially available water-dispersible conductive polymers include polythiophene-based conductive polymers (manufactured by Nagase ChemteX Corporation, product name: Denatron® Type-P series).

[0073] The type of carbon nanotube is not particularly limited; single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, and mixtures containing these in any proportion can all be used. Single-walled carbon nanotubes are preferred due to their superior conductivity.

[0074] Examples of commercially available single-walled carbon nanotubes include the SWeNT series from Toray Industries, Inc., TUBALL® from OCSiAl, Inc., and the Denatron® Type-C series (CD-100, C-169PF) from Nagase ChemteX Corporation.

[0075] Examples of commercially available multi-walled carbon nanotubes include the VGCF® series from Resonaq Corporation and Baytubes® from Bayer AG.

[0076] The composition forming the antistatic layer may contain other components besides materials that can impart antistatic properties, such as surfactants, binder resins, crosslinking agents, and solvents.

[0077] The solvent is not particularly limited, but examples include water; alcohols such as methanol, ethanol, 2-propanol, and 1-propanol; ethylene glycols such as ethylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, and tetraethylene glycol; amide compounds such as acetonitrile, N-methylformaldehyde, N,N-dimethylformamide, γ-butyrolactone, and N-methylpyrrolidone; and dimethyl sulfoxide. The solvent may be a mixed solvent of water and other solvents. If the composition contains a solvent other than water, its content is preferably 70% by mass or less, and more preferably 0.1 to 50% by mass.

[0078] The crosslinking agent is preferably soluble in the above solvent, and more preferably soluble in water. Examples of crosslinking agents include melamine-based, carbodiimide-based, oxazoline-based, epoxy-based, isocyanate-based, acrylate-based, and alkoxysilane-based compounds, and more specifically, compounds described in Japanese Patent Publication No. 2020-175610 and Japanese Patent Publication No. 2020-175611.

[0079] Examples of binder resins include epoxy resins, phenolic resins, acrylic resins, urethane resins, cellulose resins, polyether resins, polystyrene resins, oxazoline group-containing polymers, polyethylene glycol, polyvinyl alcohol, polyvinyl butyral, polyvinyl alcohol-polyethylene copolymer, polyvinyl acetal, polyvinyl alcohol-polyvinyl acetal copolymer, polyvinyl alcohol-polyvinyl butyral copolymer, and pentaerythritol. These binder resins should be used as appropriate depending on the material to which antistatic properties can be imparted.

[0080] Examples of surfactants include siloxane compounds, fluorine compounds, and polyether compounds, and more specifically, compounds described in Japanese Patent Publication No. 2020-175610 and Japanese Patent Publication No. 2020-175611.

[0081] When carbon nanotubes are included as a material that can impart antistatic properties, the carbon nanotube content in the antistatic layer is usually 0.001% by mass or more and 95% by mass or less, based on the total amount of the antistatic layer, but may also be 0.005% by mass or more and 90% by mass or less.

[0082] When a conductive polymer is included as a material that can impart antistatic properties, the content of the conductive polymer in the antistatic layer is usually 0.001% by mass or more and 95% by mass or less, based on the total amount of the antistatic layer, but may also be 0.005% by mass or more and 90% by mass or less.

[0083] When conductive fine particles are included as a material capable of providing antistatic properties, the content of conductive fine particles in the antistatic layer is usually 0.001% by mass or more and 95% by mass or less, based on the total amount of the antistatic layer, but may also be 0.005% by mass or more and 90% by mass or less.

[0084] The thickness of the antistatic layer is typically 1 nm to 500 nm, preferably 5 nm to 400 nm, and more preferably 10 nm to 300 nm, from the viewpoint of antistatic properties and transmittance.

[0085] The surface resistance of the antistatic layer is 9.0 × 10⁻⁶ from the perspective of antistatic performance. 9 It is preferable that the value is Ω / □ or less, and 5.0 × 10 9 It is more preferable that the value is Ω / □ or less, and 9.0 × 10 8 It is even more preferable that the ratio is Ω / □ or less, and 5.0 × 10 8 It is particularly preferable that the resistance is Ω / □ or less. Furthermore, the surface resistance of the antistatic layer should be 1.0 × 10⁻⁶. 3 It is preferable that the ratio be Ω / □ or greater, and 1.0 × 10 4 It is more preferable that the ratio is Ω / □ or greater, and 1.0 × 105 It is even more preferable that the resistance is Ω / □ or greater. The surface resistance of the antistatic layer can be measured by the method described in the examples.

[0086] It is preferable that the antistatic performance of the antistatic layer is higher than that of the adhesive layer. When the antistatic performance of the antistatic layer is higher than that of the adhesive layer, the antistatic performance of the antistatic layer is more easily transferred to the adhesive layer, making it easier to improve the antistatic performance of the adhesive layer and to lower the surface resistance value. For example, it is preferable that the surface resistance value of the antistatic layer is 1 / 5 or less of the surface resistance value of the adhesive layer, more preferably 1 / 10 or less, even more preferably 1 / 100 to 1 / 5, and particularly preferable 1 / 100 to 1 / 10.

[0087] <Polarizing plate 20> A polarizing plate has a structure in which a first protective layer is provided on one surface of the polarizer via a first bonding layer, and a second protective layer is provided on the other surface via a second bonding layer. The polarizing plate may be a linear polarizing plate or a composite polarizing plate including a phase difference layer. The polarizing plate shown in Figure 1 is a composite polarizing plate including a phase difference layer. The following describes each layer that makes up the polarizing plate.

[0088] <Polarizer 7> The polarizer includes a linearly polarizing layer. The linearly polarizing layer has the property of transmitting linearly polarized light with a vibration plane perpendicular to the absorption axis when unpolarized light is incident on it. The linearly polarizing layer may be a polyvinyl alcohol-based resin film (hereinafter sometimes referred to as "PVA-based film") on which iodine is adsorbed and oriented.

[0089] Examples of linearly polarized layers made of PVA-based film include polyvinyl alcohol film, partially formalized polyvinyl alcohol film, and partially saponified ethylene-vinyl acetate copolymer film, which have been subjected to iodine dyeing and stretching treatments. If necessary, the PVA-based film on which iodine has been adsorbed and oriented by the dyeing treatment may be treated with an aqueous boric acid solution, followed by a washing step to wash off the aqueous boric acid solution. Known methods can be used for each step.

[0090] Polyvinyl alcohol-based resins (hereinafter sometimes referred to as "PVA-based resins") can be produced by saponifying polyvinyl acetate-based resins. Polyvinyl acetate-based resins can be polyvinyl acetate, which is a homopolymer of vinyl acetate, or copolymers of vinyl acetate and other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having ammonium groups.

[0091] The degree of saponification of PVA resins is typically around 85-100 mol%, preferably 98 mol% or higher. PVA resins may be modified; for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can also be used. The average degree of polymerization of PVA resins is typically around 1,000-10,000, preferably 1,500-5,000. The degree of saponification and average degree of polymerization of PVA resins can be determined in accordance with JIS K 6726 (1994). If the average degree of polymerization is less than 1,000, it is difficult to obtain desirable polarization performance, and if it exceeds 10,000, film processability may be poor.

[0092] A method for manufacturing a linearly polarized film made of PVA may include the steps of preparing a base film, applying a resin solution such as a PVA resin onto the base film, and drying to remove the solvent to form a resin layer on the base film. A primer layer may be formed in advance on the surface of the base film on which the resin layer is formed. As the base film, a film made of a resin material described later as a thermoplastic resin used to form a protective film as a protective layer can be used. As the material for the primer layer, examples include a resin obtained by crosslinking a hydrophilic resin used in the linearly polarized film.

[0093] Next, the amount of solvent, such as water, in the resin layer is adjusted as needed. Then, the base film and the resin layer are uniaxially stretched, and subsequently, the resin layer is stained with iodine to adsorb and orient the iodine into the resin layer. Next, if necessary, the resin layer with the adsorbed and oriented iodine is treated with an aqueous boric acid solution, and then a washing step is performed to wash off the aqueous boric acid solution. This produces a PVA-based film in which the resin layer with the adsorbed and oriented iodine, i.e., the linearly polarized layer, is formed. Known methods can be used for each step.

[0094] The amount of boric acid in the boric acid-containing aqueous solution used to treat the PVA-based film or resin layer on which iodine is adsorbed and oriented is usually about 2 to 15 parts by mass per 100 parts by mass of water, and preferably 5 to 12 parts by mass. This boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by mass per 100 parts by mass of water, and preferably 5 to 12 parts by mass. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50°C or higher, preferably 50 to 85°C, and more preferably 60 to 80°C.

[0095] Uniaxial stretching of the PVA film, as well as the base film and resin layer, may be performed before dyeing, during dyeing, or during the boric acid treatment after dyeing, or uniaxial stretching may be performed at each of these multiple stages. The PVA film, as well as the base film and resin layer, may be uniaxially stretched in the MD direction (film transport direction), in which case uniaxial stretching may be performed between rolls with different peripheral speeds, or uniaxial stretching may be performed using a heated roll. The PVA film, as well as the base film and resin layer, may also be uniaxially stretched in the TD direction (direction perpendicular to the film transport direction), in which case the so-called tenter method can be used. Furthermore, the stretching may be dry stretching performed in air, or wet stretching performed while the PVA film or resin layer is swollen with a solvent. In order to exhibit the performance of the linearly polarized layer, the stretching ratio is 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. There is no particular upper limit to the stretching ratio, but from the viewpoint of suppressing breakage, etc., 8 times or less is preferred.

[0096] A linearly polarized film layer produced using a manufacturing method that utilizes a base film can be obtained by peeling off the base film after laminating a protective layer. This method allows for further thinning of the linearly polarized film layer.

[0097] The thickness of the linear polarizing layer, which is a PVA-based film, is preferably 1 μm or more, may be 2 μm or more, may be 5 μm or more, preferably 30 μm or less, more preferably 15 μm or less, may be 10 μm or less, or may be 8 μm or less. If the thickness of the linear polarizing layer is less than 1 μm, defects such as breakage during the process may occur, and if it exceeds 30 μm, the optical film will become too thick, which is unsuitable.

[0098] <First protective layer 10 and second protective layer 9> (First resin film 4 and second resin film 9) As the protective layer, for example, a protective film (first resin film and second resin film) is used, which is a film formed from a thermoplastic resin that has excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, stretchability, etc. Preferably, the protective film is laminated to the linearly polarized layer via a laminating layer.

[0099] Specific examples of thermoplastic resins for forming protective films (first resin film and second resin film) include cellulose resins such as triacetylcellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; polyamide resins such as nylon and aromatic polyamides; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin resins having cyclo and norbornene structures (also called norbornene resins); (meth)acrylic resins; polyarylate resins; polystyrene resins; polyvinyl alcohol resins; and mixtures thereof. From the viewpoint of optical properties, a thin protective film is preferable, but if it is too thin, the strength decreases and the processability is poor. An appropriate thickness for the protective film is 5 μm to 100 μm, preferably 10 μm to 80 μm, and more preferably 15 μm to 70 μm.

[0100] The first resin film constituting the first protective layer has a moisture permeability of 350 g / m² at a temperature of 40°C and a relative humidity of 90%. 2 Preferably, it should be less than 24 hours, and 300 g / m² 2 It is more preferable that the value be less than or equal to 24 hours, and 250 g / m². 2 It is even more preferable that the amount be less than or equal to 24 hours, and 200 g / m². 2 It is particularly preferable that the amount be less than or equal to 24 hours, and 150 g / m². 2It is extremely preferable that the moisture permeability is 24 hours or less. If the first protective layer includes a phase difference layer as described later, it is sufficient that the laminate of the phase difference layer and the first resin film satisfies the above moisture permeability. When the moisture permeability of the first resin film or the laminate of the phase difference layer and the first resin film satisfies the above range, it becomes easier to suppress the transfer of iodine in the polarizer to liquid crystal cells, touch panel input elements, etc., and durability in humid and hot environments and resistance to metal corrosion tend to improve.

[0101] The protective layer may have anti-reflective properties, anti-glare properties, hard coat properties, etc. (Hereinafter, a protective layer having such properties may be referred to as a "functional protective layer"). If the protective layer is not a functional protective layer, a surface functional layer such as an anti-reflective layer, anti-glare layer, or hard coat layer may be provided on one side of the linear polarizing plate. It is preferable that the surface functional layer be provided so as to be in direct contact with the protective layer. It is preferable that the surface functional layer be provided on the side of the protective layer opposite to the linear polarizing layer.

[0102] The first protective layer provided on the adhesive layer side of the polarizer may be a laminate of a phase difference layer, a first resin film, and a hard coat layer.

[0103] (Retardation layer 5) The phase difference layer is an optical element exhibiting a phase difference in the in-plane or thickness direction, and includes at least one phase difference film. The phase difference film may be a single film, or two or more may be bonded together with a known adhesive or tack. The phase difference film is a film exhibiting a phase difference in the in-plane or thickness direction, and may be a stretched film, or may include a cured layer of a polymerizable liquid crystal compound.

[0104] When the phase difference film is a stretched film, conventionally known stretched films can be used, and a resin film can be used to impart a phase difference by uniaxial or biaxial stretching. Examples of resin films that can be used include, but are not limited to, cellulose films such as triacetylcellulose and diacetylcellulose, polyester films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate, acrylic resin films such as polymethyl (meth)acrylate and polyethyl (meth)acrylate, polycarbonate films, polyethersulfone films, polysulfone films, polyimide films, polyolefin films, and polynorbornene films.

[0105] When the phase difference film includes the above-mentioned cured layer, known polymerizable liquid crystal compounds can be used as the polymerizable liquid crystal compound. The polymerizable liquid crystal compound is a compound having at least one polymerizable group and possessing liquid crystalline properties.

[0106] The polymerizable groups in a polymerizable liquid crystal compound refer to groups that participate in polymerization reactions, and are preferably photopolymerizable groups. Photopolymerizable groups are groups that can participate in polymerization reactions through active radicals or acids generated from photopolymerization initiators. Examples of polymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, (meth)acryloyloxy groups, oxyranyl groups, oxetanyl groups, styryl groups, and allyl groups. Among these, (meth)acryloyloxy groups, vinyloxy groups, oxyranyl groups, and oxetanyl groups are preferred, with acryloyloxy groups being more preferred. The liquid crystalline properties of a polymerizable liquid crystal compound may be thermotropic or lyotropic, and if thermotropic liquid crystals are classified by their degree of order, they may be nematic or smectic. When two or more polymerizable liquid crystal compounds are used in combination to form a cured layer of the polymerizable liquid crystal compound, it is preferable that at least one of them has two or more polymerizable groups in its molecule.

[0107] If the phase difference film includes the cured layer described above, the phase difference film may also include an alignment film. The alignment film has an orientation-regulating force that orients the polymerizable liquid crystal compound in a desired direction. The alignment film may be a vertical alignment film in which the molecular axis of the polymerizable liquid crystal compound is oriented perpendicular to the planar direction of the optical laminate, a horizontal alignment film in which the molecular axis of the polymerizable liquid crystal compound is oriented horizontally to the planar direction of the optical laminate, or a tilted alignment film in which the molecular axis of the polymerizable liquid crystal compound is tilted relative to the planar direction of the optical laminate.

[0108] The above-mentioned cured layer can be formed by applying a composition for forming a phase difference film, which contains a polymerizable liquid crystal compound, a solvent, and various additives as needed, onto an alignment film to form a coating film, and then solidifying (curing) this coating film. Alternatively, the above composition may be applied onto a base film to form a coating film, and the cured layer may be formed by stretching this coating film together with the base film. In addition to the polymerizable liquid crystal compound and solvent described above, the above composition may also contain polymerization initiators, reactive additives, leveling agents, polymerization inhibitors, etc. Known polymerizable liquid crystal compounds, solvents, polymerization initiators, reactive additives, leveling agents, polymerization inhibitors, etc., can be used as appropriate. As the base film, a film using the resin material described as a thermoplastic resin used to form the protective film as the above-mentioned protective layer can be used.

[0109] (Hard coat layer 3) The hard coat layer is a layer provided to improve the hardness and scratch resistance of the first protective layer. The hard coat layer is, for example, a cured layer of a photocurable composition (composition for forming a hard coat layer) containing a photocurable resin and a photopolymerization initiator.

[0110] Examples of photocurable resins include acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins.

[0111] When the hard coat layer forming composition is a radical-curable composition, a radical polymerization initiator can be used as the photopolymerization initiator. Examples of radical polymerization initiators include α-hydroxyacetophenone-based photopolymerization initiators, α-aminoacetophenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and intramolecular hydrogen abstraction type photopolymerization initiators. Among these, α-hydroxyacetophenone-based photopolymerization initiators and α-aminoacetophenone-based photopolymerization initiators are preferred from the viewpoint of easily shortening the curing time of the hard coat layer forming composition.

[0112] The hard coat layer may contain additives to improve its strength. The additives are not limited to inorganic microparticles, organic microparticles, or mixtures thereof.

[0113] The thickness of the hard coat layer may be, for example, 0.1 μm or more and 10 μm or less, and preferably 0.5 μm or more and 5 μm or less.

[0114] <First lamination layer 6 and second lamination layer 8> The polarizer and the first and second protective layers may be bonded together by a bonding layer. The bonding layer is an adhesive layer or a bonding agent layer. If the bonding layer is an adhesive layer, it can be formed using a known adhesive composition. Alternatively, the adhesive composition used to form the adhesive layer 1 described above may be used.

[0115] When the bonding layer is an adhesive layer, the adhesive layer can be formed by curing the curable component in the adhesive composition. Examples of adhesive compositions for forming the adhesive layer include adhesives other than pressure-sensitive adhesives (tacks), such as water-based adhesives and active energy ray-curable adhesives.

[0116] Examples of water-based adhesives include adhesives in which polyvinyl alcohol resin is dissolved or dispersed in water. There are no particular limitations on the drying method when using water-based adhesives, but for example, drying methods using a hot air dryer or an infrared dryer can be employed.

[0117] Examples of active energy ray curing adhesives include solvent-free active energy ray curing adhesives containing curable compounds that harden upon irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. By using a solvent-free active energy ray curing adhesive, the adhesion between layers can be improved.

[0118] <Separator film> The optical laminate may have a separator film attached to the surface of its adhesive layer to protect the surface of the adhesive layer until use. An optical laminate with a separator film in this manner can be manufactured by, for example, applying the above-mentioned adhesive composition onto the separator film to form an adhesive layer and then laminating a polarizing plate onto the resulting adhesive layer; applying the adhesive composition onto a polarizing plate to form an adhesive layer and then attaching a separator film to the adhesive surface for protection; or applying the above-mentioned adhesive composition onto a separator film to form an adhesive layer, then attaching another separator film to the resulting adhesive layer, peeling off one of the separator films, and then laminating a polarizing plate onto the exposed adhesive surface. The separator film may be made from a film of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyarylate as a base material, and the bonding surface of this base material with the adhesive layer may be treated with a release treatment such as silicone treatment.

[0119] [Image display device] The image display device according to the present invention includes the optical laminate described above. The image display device comprises, for example, a glass substrate and an optical laminate bonded to the glass substrate. A metal layer, such as metal wiring, may be provided on a part of the surface of the glass substrate facing the optical laminate. The metal layer may be a transparent electrode layer made of a metal oxide such as ITO.

[0120] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. For example, the optical laminate does not need to have a hard coat layer between the antistatic layer and the first resin film, and the antistatic layer and the first resin film may be in direct contact. Also, the optical laminate does not need to have a second protective layer. Furthermore, the optical laminate does not need to have a phase difference layer, and the polarizing plate may be a linear polarizing plate.

[0121] Furthermore, although Figure 1 describes an optical laminate 100 equipped with a polarizing plate 20, the optical laminate may also be a laminate equipped with an optical film having other optical functions, as long as it has an optical film, an antistatic layer, and an adhesive layer in that order. For example, instead of the polarizing plate 20 in Figure 1, the optical laminate may be equipped with a phase difference plate having a protective layer on one or both sides of the phase element; a reflective film; a semi-transparent reflective film; a brightness-enhancing film; an anti-glare film, etc. Also, one or more of these optical films may be used in combination. [Examples]

[0122] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Hereinafter, "%" and "parts" used to express the amount or content refer to "mass%" and "parts by mass," respectively, unless otherwise specified.

[0123] Weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured using a GPC instrument with three columns in series: one "TSKgel guardcolumnHHR-H(S)" and two "TSKgel GMHHR-H" columns manufactured by Tosoh Corporation. Tetrahydrofuran was used as the eluent, and measurements were performed using standard polystyrene equivalents under the following conditions: sample concentration of 2 mg / mL, sample introduction volume of 100 μL, temperature of 40°C, and flow rate of 1 mL / min.

[0124] <Manufacturing Example 1: Manufacturing of (meth)acrylic resin> A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixed solution of 81.8 parts ethyl acetate, 58.6 parts butyl acrylate, 40 parts 2-methoxyethyl acrylate, 1.0 part 2-hydroxyethyl acrylate, and 0.4 parts acrylic acid. The internal temperature was raised to 55°C while replacing the air in the apparatus with nitrogen gas to eliminate oxygen. Subsequently, the entirety of a solution of 0.14 parts azobisisobutyronitrile (polymerization initiator) dissolved in 10.0 parts ethyl acetate was added. Then, while maintaining the internal temperature at 54-56°C, ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts / hr over 1 hour from the time of addition of the polymerization initiator until the concentration of the (meth)acrylic resin excluding monomers reached 35%. Even after stopping the addition of ethyl acetate, the internal temperature was maintained at 54-56°C for 12 hours from the start of ethyl acetate addition. Finally, ethyl acetate was added to adjust the concentration of the (meth)acrylic resin to 20%, and a (meth)acrylic resin solution was prepared. The obtained (meth)acrylic resin had a weight-average molecular weight (Mw) of 1.58 million and a polystyrene equivalent (Mw / Mn) of 4.8, as determined by GPC. Furthermore, the glass transition temperature of the obtained (meth)acrylic resin was calculated to be -51.7°C using FOX's formula.

[0125] <Manufacturing Examples 2-6: Preparation of Adhesive Compositions> Adhesive compositions (1) to (5) were prepared by mixing the above (meth)acrylic resin solution (resin concentration: 20%) with the amounts (parts by mass) of a crosslinking agent, a silane compound, and an antistatic agent (ionic compound) shown in Table 1, per 100 parts by mass of the solid content of the solution, and then adding methyl ethyl ketone to bring the solid content concentration to 12% by mass. In Table 1, the amounts (parts by mass) of the (meth)acrylic resin, crosslinking agent, silane compound, and ionic compound are based on solid content.

[0126] [Table 1]

[0127] Each component in Table 1 represents the following material. ((meth)acrylic resin) A-1: Resin manufactured in manufacturing example 1 (Crosslinking agent) B-1:D-103 (Product name, ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate, manufactured by Mitsui Chemicals, Inc., solid content concentration 75% by mass) (Silane compounds) C-1: KBM-403 (Trade name, 3-Glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) (Ionic compounds) D-1: 1-Ethyl-3-methylimidazolium thiocyanate (molecular weight of imidazolium cation: 111) D-2: 1-Butyl-3-methylimidazolium thiocyanate (molecular weight of imidazolium cation: 139) D-3: 1-Ethyl-3-methylimidazolium dicyanamide D-4: Lithium bis(fluorosulfonyl)imide D-5: 1-Ethyl-3-methylimidazoliumbis(fluorosulfonyl)imide

[0128] <Manufacturing Example 7: Fabrication of Polarizers> A 30 μm thick polyvinyl alcohol (PVA) resin film was immersed in pure water at 21.5°C for 80 seconds (swelling treatment), then immersed for 55 seconds in an aqueous solution at 23°C with a potassium iodide / boric acid / water mass ratio of 2 / 2 / 100 and containing 1.0 mM iodine (dyeing step). Subsequently, it was immersed for 76 seconds in an aqueous solution at 63°C with a potassium iodide / boric acid / water mass ratio of 2.5 / 4 / 100 (first crosslinking step). Subsequently, it was immersed for 10 seconds in an aqueous solution at 45°C with a potassium iodide / boric acid / zinc chloride / water mass ratio of 3 / 5.5 / 0.6 / 100 (second crosslinking step, metal ion treatment step). After that, it was washed by immersion in a washing bath (washing step) and dried at 38°C (drying step) to obtain a 12 μm thick polarizer with iodine adsorbed and oriented on the PVA resin film. Stretching was mainly performed during the dyeing process and the first crosslinking process, and the total stretching ratio was 5.85 times.

[0129] <Manufacturing Example 8: Fabrication of a phase difference layer with a hard coat layer> On a polyolefin resin film (thickness 24 μm) as the base layer (first resin film), an alignment film (thickness 40 nm) and a liquid crystal curing film (thickness 0.5 μm) (collectively referred to as the "phase difference layer") were formed in this order by the method described in paragraphs

[0261] to

[0266] of Japanese Patent Application Publication No. 2016-027431, thereby obtaining a phase difference layer with a base layer. The moisture permeability of the obtained phase difference layer with a base layer was measured in an atmosphere at a temperature of 40°C and a relative humidity of 90% in accordance with Annex B of JIS K7129:2008. The moisture permeability of the phase difference layer with a base layer was 104 g / m². 2 It was / 24hr.

[0130] A hard coat layer forming composition was obtained by mixing and stirring 100 parts by mass of a photocurable resin (product name: Beamset 710, pentaerythritol polyacrylate, manufactured by Arakawa Chemical Industries, Ltd.), 3.4 parts by mass of a photopolymerization initiator (product name: Omnirad 2959, manufactured by IGM Resins), and 85.6 parts by mass of a solvent (methyl ethyl ketone).

[0131] A hard coat layer-forming composition was applied to the surface of a polyolefin resin film with a base layer and phase difference layer using a bar coating method. After drying the coating in a 60°C oven for 150 seconds, it was exposed to light at an illuminance of 400 mW / cm using an electrodeless lamp H bulb manufactured by Fusion UV Systems. 2 , light intensity 300mJ / cm 2 The coating film was irradiated with ultraviolet light to form a hard coat layer, obtaining a phase difference layer with a hard coat layer. The thickness of the hard coat layer after drying was 1 μm.

[0132] <Manufacturing Example 9: Preparation of Water-Based Adhesive> 50 g of a modified polyvinyl alcohol resin containing acetoacetyl groups (product name: Gosenex Z-410, manufactured by Mitsubishi Chemical Corporation) was dissolved in 950 g of pure water, heated at 90°C for 2 hours, and then cooled to room temperature to obtain a PVA solution. This PVA solution, pure water, maleic acid, glyoxal, and urea were blended so that the concentration of the polyvinyl alcohol resin was 3.0% by mass, the concentration of the maleic acid was 0.01% by mass, the concentration of the glyoxal was 0.15% by mass, and the concentration of the urea was 0.1% by mass to obtain a water-based adhesive.

[0133] <Manufacturing Example 10: Fabrication of Polarizing Plates> A triacetylcellulose film (product name: TJ40UL, thickness: 40 μm, manufactured by Fujifilm Corporation) was prepared as a protective film (second resin film) and subjected to saponification treatment. The above triacetylcellulose film and the phase difference layer with a hard coat layer prepared in Production Example 8 were bonded to each face of the polarizer prepared in Production Example 7 using a roll laminating machine via the water-based adhesive prepared in Production Example 9, and dried at a temperature of 80°C for 5 minutes to obtain a polarizing plate. The thickness of the water-based adhesive layer was 100 nm on both sides. Here, the phase difference layer with a hard coat layer was bonded so that its phase difference layer surface faced the polarizer. The structure of the obtained polarizing plate was triacetylcellulose film / water-based adhesive layer / polarizer / water-based adhesive layer / phase difference layer / polyolefin resin film / hard coat layer.

[0134] [Example 1: Fabrication of an optical laminate] (1) Formation of an antistatic layer A 50% aqueous ethanol solution was mixed with a CNT-based conductive coating agent (manufactured by Nagase ChemteX Corporation, trade name "Denatron C-169PF-A") and a crosslinking agent for CNT-based conductive coating agents (manufactured by Nagase ChemteX Corporation, trade name "Denatron C-169PF-B") in a ratio of Denatron C-169PF-A:C-169PF-B = 3:2 (mass ratio). The mixture was stirred for 10 minutes to prepare a coating solution for forming an antistatic layer with a concentration of 0.5%. The hard coat layer surface of the polarizing plate prepared in Production Example 10 was subjected to corona treatment (4.0 kJ / m²). 2The coating solution prepared above was applied, heated at 100°C for 3 minutes to dry, and a 25 nm thick antistatic layer (conductive layer) was formed. This resulted in obtaining a polarizing plate with an antistatic layer.

[0135] The surface resistance of the antistatic layer of the obtained polarizing plate with an antistatic layer was measured using a surface resistivity measuring device (manufactured by Nitto Seikou Analytech Co., Ltd., product name "Hiresta UX MCP-800"). The surface resistance of the antistatic layer was 3.76 × 10⁻⁶. 7 The result was Ω / □. The applied voltage was 100V, and the pressurization time was 30 seconds.

[0136] (2) Formation of the adhesive layer A solution of the adhesive composition (1) prepared in Production Example 2 was applied using an applicator to the release-treated surface of a separator film made of polyethylene terephthalate film that had been subjected to a release treatment (product name "Diafoil MRV38 (V04)", manufactured by Mitsubishi Chemical Corporation), and dried at 80°C for 3 minutes to produce an adhesive layer with a separator film. The thickness of the resulting adhesive layer was 25 μm.

[0137] The adhesive layer surface of the adhesive layer with a separator film was laminated to the antistatic layer surface of the polarizing plate with an antistatic layer obtained above using a laminator, and then cured for 7 days at a temperature of 23°C and a relative humidity of 60% to obtain an optical laminate (1) having a laminated structure of polarizing plate / antistatic layer / adhesive layer / separator film.

[0138] [Example 2: Fabrication of an optical laminate] An optical laminate (2) was obtained in the same manner as in Example 1, except that adhesive composition (1) was replaced with adhesive composition (2).

[0139] [Comparative Example 1: Fabrication of an Optical Laminate] An optical laminate (3) was obtained in the same manner as in Example 1, except that adhesive composition (1) was replaced with adhesive composition (3).

[0140] [Comparative Example 2: Fabrication of Optical Laminates] An optical laminate (4) was obtained in the same manner as in Example 1, except that adhesive composition (1) was replaced with adhesive composition (4).

[0141] [Comparative Example 3: Fabrication of Optical Laminates] An optical laminate (5) was obtained in the same manner as in Example 1, except that adhesive composition (1) was replaced with adhesive composition (5).

[0142] [Comparative Example 4: Fabrication of Optical Laminates] A solution of the adhesive composition (1) prepared in Production Example 2 was applied using an applicator to the release-treated surface of a separator film made of polyethylene terephthalate film that had been subjected to a release treatment (product name "Diafoil MRV38 (V04)", manufactured by Mitsubishi Chemical Corporation), and dried at 80°C for 3 minutes to produce an adhesive layer with a separator film. The thickness of the resulting adhesive layer was 25 μm.

[0143] Corona treatment (4.0 kJ / m³) was applied to the hard coat layer side of the polarizing plate manufactured in manufacturing example 10. 2 After applying the adhesive layer to the adhesive layer with the separator film and laminating it with a laminator, the material was cured for 7 days at a temperature of 23°C and a relative humidity of 60% to obtain an optical laminate (6) having a laminated structure of polarizing plate / adhesive layer / separator film.

[0144] [Comparative Example 5: Fabrication of Optical Laminates] An optical laminate (7) was obtained in the same manner as in Comparative Example 4, except that adhesive composition (1) was replaced with adhesive composition (2).

[0145] [Comparative Example 6: Fabrication of Optical Laminates] An optical laminate (8) was obtained in the same manner as in Comparative Example 4, except that adhesive composition (1) was replaced with adhesive composition (3).

[0146] [Comparative Example 7: Fabrication of Optical Laminates] An optical laminate (9) was obtained in the same manner as in Comparative Example 4, except that adhesive composition (1) was replaced with adhesive composition (4).

[0147] [Comparative Example 8: Fabrication of Optical Laminates] An optical laminate (10) was obtained in the same manner as in Comparative Example 4, except that adhesive composition (1) was replaced with adhesive composition (5).

[0148] <Evaluation of antistatic properties of optical laminates> The separator film of the obtained optical laminate (1) was peeled off, and the surface resistance of the exposed adhesive layer was measured using a surface resistivity measuring device (manufactured by Nitto Seikou Analytech Co., Ltd., product name "Hiresta UX MCP-800") to evaluate its antistatic properties. The applied voltage was 100V, and the pressurization time was 30 seconds. The surface resistance values ​​of optical laminates (1) to (10) were measured in the same manner. The results are shown in Table 2. Surface resistance value of 1.0 × 10 8 If the value is less than Ω / □, it was determined that the antistatic properties are good.

[0149] Here, the surface resistance of the adhesive layer in optical laminates (6) to (10) can be considered as the surface resistance of the single adhesive layer. That is, the surface resistance of the adhesive layer in optical laminates (6) to (10) can each be considered as the surface resistance of the single adhesive layer in optical laminates (1) to (5).

[0150] <Evaluation of metal corrosion resistance of optical laminates> A glass substrate (manufactured by Geomatec Co., Ltd.) was prepared by laminating a metallic aluminum layer approximately 500 nm thick onto an alkali-free glass surface by sputtering. The optical laminate (1) was cut into 50 mm x 50 mm test pieces, and after peeling off the separator film, it was bonded to the metallic aluminum layer surface via the exposed adhesive layer to obtain measurement samples. The obtained measurement samples were stored in an oven at 85°C and 85% relative humidity for 240 hours. Afterward, the condition of the metallic aluminum layer in the area where the adhesive layer was attached was observed by shining light from the back of the glass substrate of the measurement sample and viewing it through a magnifying glass (loupe) on the surface of a polarizing plate. Pitting corrosion (the formation of holes with a diameter of 0.1 mm or more that can transmit light) was evaluated according to the following criteria. Optical laminates (1) to (10) were evaluated in the same manner. The results are shown in Table 2.

[0151] 5: No pitting corrosion or clouding is observed on the surface of the metallic aluminum layer. 4. The number of pitting corrosion lesions on the surface of the metallic aluminum layer is 10 or less. 3: The number of pitting corrosion lesions on the surface of the metallic aluminum layer is between 11 and 19. 2: The number of pitting corrosion lesions on the surface of the metallic aluminum layer is 20 or more. 1: Numerous (more than 20) pitting corrosion lesions have occurred across the entire surface of the metallic aluminum layer, and clouding has also occurred.

[0152] [Table 2]

[0153] As shown in Table 2, the optical laminate of the present invention has better antistatic performance. Furthermore, the optical laminate of the present invention has good metal corrosion resistance. [Explanation of Symbols]

[0154] 1...Adhesive layer, 2...Antistatic layer, 3...Hard coat layer, 4...First resin film, 5...Phase difference layer, 6...First bonding layer, 7...Polarizer, 8...Second bonding layer, 9...Second resin film (second protective layer), 10...First protective layer, 20...Polarizing plate (optical film), 100...Optical laminate.

Claims

1. An optical laminate comprising an optical film, an antistatic layer, and an adhesive layer in this order, The adhesive layer comprises (meth)acrylic resin (A), crosslinking agent (B), silane compound (C), and antistatic agent (D). The antistatic agent (D) is an optical laminate containing an ionic compound comprising an imidazolium cation and a thiocyano group-containing anion.

2. The optical laminate according to claim 1, wherein the (meth)acrylic resin (A) contains structural units derived from alkoxyalkyl (meth)acrylate.

3. The optical laminate according to claim 1, wherein the antistatic layer comprises at least one selected from the group consisting of conductive polymers, conductive fine particles, and carbon nanotubes.

4. The optical laminate according to claim 1, wherein the optical film comprises a first resin film and a hard coat layer disposed on the antistatic layer side of the first resin film.

5. The optical laminate according to claim 1, wherein the optical film comprises a first resin film and a polarizer disposed on the opposite side of the first resin film from the antistatic layer.

6. The moisture permeability of the first resin film is 350 g / m² at a temperature of 40°C and a relative humidity of 90%. ２ The optical laminate according to claim 5, wherein the heating time is 24hr or less.

7. The optical film has a phase difference layer disposed between the first resin film and the polarizer. The moisture permeability of the laminate of the first resin film and the phase difference layer is 350 g / m² at a temperature of 40°C and a relative humidity of 90%. ２ The optical laminate according to claim 5, wherein the heating time is 24hr or less.

8. The optical laminate according to claim 5, wherein the optical film has a second resin film disposed on the opposite side of the polarizer from the first resin film.

9. An image display device comprising an optical laminate according to any one of claims 1 to 8.

Images