Optical stack

Abstract

To provide an optical laminate that can effectively reduce transition of a dichroic dye contained in a polarizing film to a conductive layer to prevent deterioration of the conductive layer.SOLUTION: An optical laminate has a first cured material layer that is formed of a cured material of a curable composition containing a polymerizable compound, an adhesive layer, and a conductive layer laminated in this order on one face of a polarizing film that contains a dichroic dye in a polyvinyl alcohol resin, where the first cured material layer has a rate of increase in absorbance represented by the following formula (1) of 30% or less. (1) the rate of increase in absorbance (%)=(after immersion Abs(360nm)-before immersion Abs(360nm)) / before immersion Abs(360nm)×100.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an optical laminate used in an image display panel or the like. [Background technology]

[0002] Conventionally, an optical laminate has been known in which a protective film is laminated, via an adhesive, on one side of a polarizing film in which a dichroic dye such as iodine is adsorbed and oriented in a polyvinyl alcohol-based resin film. Patent Document 1, for example, describes an optical cationically curable adhesive (curable composition) containing an aliphatic epoxy, an alicyclic epoxy and / or an oxetane, and a photopolymerization initiator as an adhesive used to form such an optical laminate, and the cured product functions as an adhesive.

[0003] In recent years, transparent conductive films such as indium tin oxide (ITO) thin films have been widely used in display devices. For example, it is known that the transparent conductive film is formed as an antistatic layer on the side of a transparent substrate constituting a liquid crystal cell opposite the side in contact with the liquid crystal layer of a liquid crystal display device using a liquid crystal cell such as an in-plane switching (IPS) system. In addition, a transparent conductive film having the transparent conductive film formed on a transparent resin film is used as an electrode substrate for a touch panel. For example, input devices using a liquid crystal display device or image display device in combination with the touch panel used in a mobile phone, portable music player, etc. have become widely used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-063397 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a conductive layer such as an ITO layer is laminated on the polarizing film side of the optical laminate described in Patent Document 1 via a pressure-sensitive adhesive layer, the dichroic dye contained in the polarizing film relatively easily permeates the pressure-sensitive adhesive layer and may migrate to the conductive layer, which may cause malfunctions such as poor sensing. Such migration of the dichroic dye from the polarizing film becomes particularly noticeable in high-temperature, high-humidity environments, so there is a need for an optical laminate that can prevent deterioration of the conductive layer due to the dichroic dye contained in the polarizing film migrating to the conductive layer via the pressure-sensitive adhesive layer, even in high-temperature, high-humidity environments.

[0006] Therefore, an object of the present invention is to provide an optical laminate that can effectively suppress the migration of a dichroic dye contained in a polarizing film to a conductive layer and prevent deterioration of the conductive layer. [Means for solving the problem]

[0007] The present invention provides the following preferred embodiments [1] to [6]. [1] An optical laminate in which a first cured product layer composed of a cured product of a curable composition containing a polymerizable compound, an adhesive layer, and a conductive layer are laminated in this order on one surface of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, The first cured product layer has an increase rate of absorbance represented by the following formula (1) of 30% or less. Absorbance increase rate (%) = (Abs (360 nm) after immersion - Abs (360 nm) before immersion) / Abs (360 nm) before immersion × 100 (1) [In the formula, "Abs(360nm) after immersion" refers to the absorbance at 360nm after the cured product was immersed in a 50% aqueous potassium iodide solution for 100 hours in the atmosphere at a temperature of 23°C and a relative humidity of 60%, and "Abs(360nm) before immersion" refers to the absorbance at 360nm before the cured product was immersed in the 50% aqueous potassium iodide solution.] [2] An optical laminate in which a first cured product layer composed of a cured product of a curable composition containing a polymerizable compound, an adhesive layer, and a conductive layer are laminated in this order on one surface of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, an optical laminate, wherein the polymerizable compound includes an oxetane compound having two or more oxetanyl groups, and the content of the oxetane compound is 40 parts by mass or more relative to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition. [3] The optical layered body according to [1] or [2], wherein the thickness of the first cured product layer is 0.1 to 15 μm. [4] The cured product constituting the first cured product layer is a photocurable composition containing the polymerizable compound. The optical laminate according to any one of [1] to [3], which is an object. [5] The optical laminate according to any one of [1] to [4], wherein a second cured product layer and a protective film are laminated on the surface of the polarizing film opposite to the first cured product layer. [6] The moisture permeability of the protective film is 1200g at a temperature of 23°C and a relative humidity of 55%. / (m 2 The optical laminate according to [5], wherein the time required for the optical laminate to be used is 24 hours or less. [Effects of the Invention]

[0008] The optical laminate of the present invention can suppress the migration of the dichroic dye contained in the polarizing film to the conductive layer, and can effectively suppress corrosion of the conductive layer. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a configuration of one embodiment of an optical laminate of the present invention. [Figure 2] 1 is a cross-sectional view showing a configuration of one embodiment of an optical laminate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0011] The configuration of one embodiment of the optical laminate of the present invention will be described with reference to Fig. 1. The optical laminate 10 of the present invention has a structure in which a first cured product layer 2, an adhesive layer 3, and a conductive layer 4 are laminated in this order on one surface of a polarizing film 1. If necessary, a protective film 6 may be provided on the surface of the polarizing film 1 opposite the first cured product layer via a second cured product layer 5. Furthermore, in the embodiment of Fig. 1, the conductive layer 4 of the optical laminate 10 is laminated on a substrate X.

[0012] The optical laminate of the present invention may also have a first protective film 7 between the first cured product layer 2 and the adhesive layer 3. This embodiment is shown in Fig. 2. If necessary, the optical laminate 10 may also have a second protective film 6 on the surface of the polarizing film 1 opposite to the first cured product layer 2, with a second cured product layer 5 interposed therebetween. In the embodiment of Fig. 2, the conductive layer 4 of the optical laminate 10 is laminated on a substrate X. Hereinafter, each of the constituent components of the optical layered body of the present invention will be described in detail.

[0013] [First cured material layer] The optical laminate of the present invention has a first cured product layer composed of a cured product of a curable composition containing a polymerizable compound (hereinafter, sometimes referred to as curable composition (1)) on one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin.

[0014] The first cured product layer has an increase rate of absorbance represented by the following formula (1) of 30% or less. Absorbance increase rate (%) = (Abs (360 nm) after immersion - Abs (360 nm) before immersion) / Abs (360 nm) before immersion × 100 (1) [In the formula, "Abs(360nm) after immersion" refers to the absorbance at 360nm after the cured product was immersed in a 50% aqueous potassium iodide solution for 100 hours in the atmosphere at a temperature of 23°C and a relative humidity of 60%, and "Abs(360nm) before immersion" refers to the absorbance at 360nm before the cured product was immersed in the 50% aqueous potassium iodide solution.]

[0015] Even when the first cured material layer is immersed in a 50% potassium iodide aqueous solution for 100 hours, the increase in absorbance, as expressed by the above formula (1), is 30% or less. This indicates that the first cured material layer has relatively low absorbency for iodine (dichroic dye). Therefore, the optical laminate of the present invention can effectively suppress the migration of iodine (dichroic dye) contained in the polarizing film to the first cured material layer, and can prevent corrosion of the conductive layer (e.g., ITO layer) by iodine (dichroic dye). Furthermore, the optical performance of the optical laminate can be maintained.

[0016] The rate of increase in absorbance represented by the formula (1) is preferably 25% or less, more preferably 20% or less, even more preferably 15% or less, and particularly preferably 10% or less. When the rate of increase in absorbance is equal to or less than the above value, the migration of iodine (dichroic dye) contained in the polarizing film to the first cured product layer can be more effectively suppressed, as described above, and corrosion of the conductive layer and deterioration of the optical performance of the optical laminate can be more effectively prevented.

[0017] The polymerizable compound contained in the curable composition (1) is not particularly limited as long as it can form a cured product that constitutes the first cured product layer. Examples of the polymerizable compound include active energy ray-curable resin compositions, water-soluble resin compositions, and water-dispersible resin compositions. Among these, active energy ray-curable resin compositions are preferred from the viewpoint of process simplification, and particularly preferred are (meth)acrylate compounds including epoxy acrylate, urethane acrylate, etc., acrylamide compounds, oxetane compounds, and epoxy compounds.

[0018] In a preferred embodiment, the cured product constituting the first cured product layer is a photocured product of a curable composition containing a polymerizable compound, and therefore the polymerizable compound is preferably a photocurable compound.

[0019] The polymerizable compound preferably contains an oxetane compound having two or more oxetanyl groups (oxetane rings) in the molecule (hereinafter, may be referred to as "oxetane compound (A)").

[0020] The oxetane compound (A) is a compound having two or more oxetanyl groups in the molecule and may be an aliphatic compound, an alicyclic compound, or an aromatic compound. Specific examples of the oxetane compound (A) include 1,4-bis[{(3-ethyloxetan-3-yl)methoxy}methyl]benzene (also known as xylylene bisoxetane) and bis(3-ethyl-3-oxetanylmethyl)ether. These oxetane compounds (A) may be used alone or in combination. By including the oxetane compound (A), a dense cured product with a high crosslink density can be obtained. By providing a cured product layer with a high crosslink density on one side of the polarizing film, migration of the dichroic dye from the polarizing film can be effectively suppressed.

[0021] The content of the oxetane compound (A) is, for example, 40 parts by mass or more, preferably 45 parts by mass or more, and more preferably 50 parts by mass or more, relative to 100 parts by mass of all polymerizable compounds contained in the curable composition (1). The content of the oxetane compound (A) is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and particularly preferably 65 parts by mass or less, relative to 100 parts by mass of all polymerizable compounds contained in the curable composition (1). The content of the oxetane compound (A) may be a combination of these lower and upper limits, and may be preferably 40 to 65 parts by mass, more preferably 45 to 60 parts by mass, relative to 100 parts by mass of all polymerizable compounds contained in the curable composition (1). The content of the oxetane compound (A) is, for example, 35 parts by mass or more, preferably 40 parts by mass or more, and more preferably 45 parts by mass or more, relative to 100 parts by mass of the total amount of the curable composition (1). When the content of the oxetane compound (A) is equal to or more than the above value, migration of the dichroic dye contained in the polarizing film to the first cured product layer can be more effectively suppressed, and corrosion of the conductive layer and deterioration of the optical performance of the optical laminate can be more effectively prevented.

[0022] The polymerizable compound preferably further contains an epoxy compound (B). The epoxy compound is preferably at least one selected from (B1) an aliphatic epoxy compound having two or more epoxy groups (hereinafter, sometimes referred to as "aliphatic epoxy compound (B1)"), (B2) an alicyclic epoxy compound having two or more epoxy groups (hereinafter, sometimes referred to as "alicyclic epoxy compound (B2)"), and (B3) an aromatic epoxy compound having one or more aromatic rings (hereinafter, sometimes referred to as "aromatic epoxy compound (B3)").

[0023] The aliphatic epoxy compound (B1) is a compound having at least two oxirane rings bonded to aliphatic carbon atoms in the molecule. Examples of the aliphatic epoxy compound (B1) include bifunctional epoxy compounds such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, and neopentyl glycol diglycidyl ether; and trifunctional or higher epoxy compounds such as trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether.

[0024] When an aliphatic epoxy compound (B1) is contained, from the viewpoint of adhesion between the polarizing film and the protective film or adhesive layer, a bifunctional epoxy compound (also called an aliphatic diepoxy compound) having two oxirane rings bonded to aliphatic carbon atoms in the molecule is preferred, and an aliphatic diepoxy compound represented by the following formula (I) is more preferred. When the curable composition contains an aliphatic diepoxy compound represented by the following formula (I) as the aliphatic epoxy compound (B1), a curable composition having low viscosity and easy application can be obtained.

[0025] [ka] In formula (I), Z represents an alkylene group having 1 to 9 carbon atoms, an alkylidene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a group represented by the formula -C m H 2m -Z 1 -Cn H 2n -Z represents a divalent group represented by the formula 1 - represents -O-, -CO-O-, -O-CO-, -SO2-, -SO- or CO-, and m and n each independently represent an integer of 1 or more, provided that the sum of m and n is 9 or less.

[0026] The divalent alicyclic hydrocarbon group may be, for example, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, and examples thereof include divalent residues represented by the following formula (I-1).

[0027] [ka]

[0028] Specific examples of the compound represented by formula (I) include diglycidyl ethers of alkanediols; diglycidyl ethers of oligoalkylene glycols having up to about 4 repeating units; and diglycidyl ethers of alicyclic diols.

[0029] Examples of diols (glycols) capable of forming the compound represented by formula (I) include alkanediols such as ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol; Oligoalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and dipropylene glycol; Examples include alicyclic diols such as cyclohexanediol and cyclohexanedimethanol.

[0030] In the present invention, the aliphatic epoxy compound (B1) is preferably 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, or neopentyl glycol diglycidyl ether, from the viewpoint of being able to obtain a curable composition with low viscosity and easy application. In terms of being able to maintain optical performance, 1,6-hexanediol diglycidyl ether or pentaerythritol polyglycidyl ether is preferred. As the aliphatic epoxy compound (B1), one aliphatic epoxy compound may be used alone, or different types may be used in combination.

[0031] When the curable composition (1) contains an aliphatic epoxy compound (B1), the content of the aliphatic epoxy compound (B1) is preferably 1 to 40 parts by mass, more preferably 3 to 30 parts by mass, even more preferably 5 to 20 parts by mass, and particularly preferably 7 to 15 parts by mass, relative to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition. When the content of the aliphatic epoxy compound (B1) is within the above range, the viscosity of the curable composition (1) is low, making it possible to obtain a composition that is easy to apply.

[0032] The alicyclic epoxy compound (B2) is a compound having two or more epoxy groups bonded to an alicyclic ring in the molecule. The "epoxy group bonded to an alicyclic ring" refers to a compound represented by the following formula (a): [ka] In the above formula (a), m is an integer of 2 to 5.

[0033] (CH2) in the above formula (a) m A compound in which two or more groups formed by removing one or more hydrogen atoms from (CH2) are bonded to another chemical structure can be an alicyclic epoxy compound (B2). m One or more hydrogen atoms therein may be appropriately substituted with a straight-chain alkyl group such as a methyl group or an ethyl group.

[0034] Among these, from the viewpoints of achieving a high glass transition temperature of the cured product and excellent adhesion between the polarizing film and the protective film, alicyclic epoxy compounds having an epoxycyclopentane structure (where m = 3 in the above formula (a)) or an epoxycyclohexane structure (where m = 4 in the above formula (a)) are preferred, and alicyclic diepoxy compounds represented by the following formula (II) are more preferred. When the curable composition (1) contains the alicyclic diepoxy compound represented by the following formula (II) as compound (B2), the cured layer obtained after curing of the curable composition has high elasticity, and cracking of the polarizing film due to thermal shrinkage can be suppressed.

[0035] [ka] In formula (II), R 1 and R 2 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and when the alkyl group has 3 or more carbon atoms, it may have an alicyclic structure. The alkyl group having 1 to 6 carbon atoms may be a linear or branched alkyl group, and examples of the alkyl group having an alicyclic structure include a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group.

[0036] In formula (II), X represents an oxygen atom, an alkanediyl group having 1 to 6 carbon atoms, or a group represented by the following formulas (IIa) to (IId): [ka] represents a divalent group represented by any one of the following: Examples of the alkanediyl group having 1 to 6 carbon atoms include a methylene group, an ethylene group, and a propane-1,2-diyl group.

[0037] When X in formula (II) is a divalent group represented by any one of formulas (IIa) to (IId), Y in each formula 1 ~Y 4 are each independently an alkanediyl group having 1 to 20 carbon atoms, and when the alkanediyl group has 3 or more carbon atoms, it may have an alicyclic structure. a and b each independently represent an integer of 0 to 20.

[0038] Examples of the compound represented by formula (II) include the following compounds A to G. Note that the chemical formulae A to G shown thereafter correspond to compounds A to G, respectively.

[0039] A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate C: Ethylenebis(3,4-epoxycyclohexanecarboxylate) D: Bis(3,4-epoxycyclohexylmethyl) adipate E: Bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate F: Diethylene glycol bis(3,4-epoxycyclohexyl methyl ether) G: Ethylene glycol bis(3,4-epoxycyclohexyl methyl ether)

[0040] [ka]

[0041] In the present invention, as the alicyclic epoxy compound (B2), 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate is more preferred from the viewpoint of easy availability. Also, from the viewpoint of effectively suppressing corrosion of the conductive layer, 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol is preferred. In particular, when 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate and 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol are used in combination as the alicyclic epoxy compound (B2), corrosion of the conductive layer can be effectively suppressed. As the alicyclic epoxy compound (B2), one type of alicyclic epoxy compound may be used alone, or different types may be used in combination.

[0042] When the curable composition (1) contains an alicyclic epoxy compound (B2), the content of the alicyclic epoxy compound (B2) is preferably 3 to 70 parts by mass, more preferably 10 to 60 parts by mass, even more preferably 20 to 55 parts by mass, and particularly preferably 25 to 50 parts by mass, relative to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition (1). When the content of the alicyclic epoxy compound (B2) is within the above range, curing by irradiation with active energy rays such as ultraviolet rays proceeds quickly, and a cured layer with sufficient hardness can be easily formed.

[0043] The aromatic epoxy compound (B3) is a compound having one or more aromatic rings in the molecule, and specific examples thereof include the following. Mono- / polyglycidyl ethers of monohydric phenols having at least one aromatic ring, such as phenol, cresol, and butylphenol, or their alkylene oxide adducts, such as glycidyl ethers of bisphenol A, bisphenol F, or compounds obtained by further adding alkylene oxides to these, and epoxy novolac resins; Glycidyl ethers of aromatic compounds with two or more phenolic hydroxyl groups, such as resorcinol, hydroquinone, and catechol; Mono- / polyglycidyl ethers of aromatic compounds with two or more alcoholic hydroxyl groups, such as benzenedimethanol, benzenediethanol, and benzenedibutanol; Polybasic acids with two or more carboxylic acids, such as phthalic acid, terephthalic acid, and trimellitic acid Glycidyl esters of aromatic compounds; Glycidyl esters of benzoic acids such as benzoic acid, toluic acid, and naphthoic acid; Epoxidized products of styrene oxide or divinylbenzene, etc.

[0044] When the aromatic epoxy compound (B3) is contained, from the viewpoint of reducing the viscosity of the curable composition, it is preferable that the aromatic epoxy compound (B3) contains at least one selected from the group consisting of glycidyl ethers of phenols, glycidyl etherified products of aromatic compounds having two or more alcoholic hydroxyl groups, glycidyl etherified products of polyhydric phenols, glycidyl esters of benzoic acids, glycidyl esters of polybasic acids, and epoxidized products of styrene oxide or divinylbenzene. In addition, the aromatic epoxy compound (B3) preferably has an epoxy equivalent of 80 to 500, in order to improve the curability of the curable composition. As the aromatic epoxy compound (B3), one type of aromatic epoxy compound may be used alone, or different types may be used in combination.

[0045] As the aromatic epoxy compound (B3), commercially available products can be used, for example, Denacol EX-121, Denacol EX-141, Denacol EX-142, Denacol EX-145, Denacol EX-146, Denacol EX-147, Denacol EX-201, Denacol EX-203, Denacol EX-711, Denacol EX-721, Oncoat EX-1020, Oncoat EX-1030, Oncoat EX-1040, Oncoat EX-1050, Oncoat EX-1060, Oncoat EX-1070, Oncoat EX-1080, Oncoat EX-1090, Oncoat EX-2101, Oncoat EX-2112, Oncoat EX-2113, Oncoat EX-2114, Oncoat EX-2115, Oncoat EX-2116, Oncoat EX-2117, Oncoat EX-2118, Oncoat EX-2119, Oncoat EX-2129, Oncoat EX-2121, Oncoat EX-2122, Oncoat EX-2123, Oncoat EX-2124, Oncoat EX-2125, Oncoat EX-2126, Oncoat EX-2127, Oncoat EX-2128, Oncoat EX-2129, Oncoat EX-2130, Oncoat EX-2131, Oncoat EX-2132, Oncoat EX-2133, Oncoat EX-2134, Oncoat EX-2135, Oncoat EX-2136, Oncoat EX-2137, Oncoat EX-2138, Oncoat EX-2139, Oncoat EX-2140, Oncoat EX-2141, Oncoat EX-2142, Onco Oncoat EX-1040, Oncoat EX-1050, Oncoat EX-1051, Oncoat EX-1010, Oncoat EX-1011, Oncoat 1012 (all manufactured by Nagase ChemteX Corporation); Oxol PG-100, Oxol EG-200, Oxol EG-210, Oxol EG-250 (all manufactured by Osaka Gas Chemicals Co., Ltd.); HP4032, HP4032D, HP4700 (all manufactured by DIC Corporation) ESN-475V (Nippon Steel Sumikin Chemical Co., Ltd.); Epicoat YX8800, jER828EL (Mitsubishi Chemical Co., Ltd.); Marproof G-0105SA, Marproof G-0130SP (NOF Corp.); Epiclon N-665, Epiclon HP-7200 (all manufactured by DIC Corporation); EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, XD-1000, NC-3000, EPPN-50 1H, EPPN-501HY, EPPN-502H, NC-7000L (all manufactured by Nippon Kayaku Co., Ltd.); ADEKA GLYCIROL ED-501, ADEKA GLYCIROL ED-502, ADEKA GLYCIROL ED-509, ADEKA GLYCIROL ED-529, ADEKA RESIN EP-4000, ADEKA RESIN EP-4005, ADEKA RESIN EP-4100, ADEKA RESIN EP-4901 (all manufactured by ADEKA Corporation); TECHMORE VG-3101L, EPOX-MKR710, EPOX-MKR151 (all manufactured by Printec Co., Ltd.), and the like.

[0046] The curable composition contains the aromatic epoxy compound (B3), which makes the curable composition a hydrophobic resin, and the resulting cured layer is also hydrophobic, which prevents moisture from entering from the outside under high temperature and high humidity conditions and effectively suppresses the migration of the dichroic dye (iodine) contained in the polarizing film.

[0047] When the curable composition (1) contains an aromatic epoxy compound (B3), the content of the aromatic epoxy compound (B3) is preferably 1 to 70 parts by mass, more preferably 5 to 60 parts by mass, even more preferably 7 to 55 parts by mass, and particularly preferably 10 to 50 parts by mass, relative to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition (1). When the content of the aromatic epoxy compound (B3) is within the above range, the hydrophobicity of the cured product layer can be improved, and the permeability of the dichroic dye (iodine) through the cured product layer can be reduced.

[0048] When the curable composition (1) contains an oxetane compound (A) and an alicyclic epoxy compound (B2), the mass ratio (WB2 / WA) of the content (WB2) of the alicyclic epoxy compound (B2) to the content (WA) of the oxetane compound (A) is preferably 0.05 to 1.5. When the curable composition (1) contains an oxetane compound (A) and an aliphatic epoxy compound (B1), the mass ratio (WB1 / WA) of the content (WB1) of the aliphatic epoxy compound (B1) to the content (WA) of the oxetane compound (A) is preferably 0.1 to 0.5. When the curable composition (1) contains an oxetane compound (A) and an aromatic epoxy compound (B3), the mass ratio (WB3 / WA) of the content (WB3) of the aromatic epoxy compound (B1) to the content (WA) of the oxetane compound (A) is preferably 0.1 to 1.5.

[0049] The curable composition (1) may contain a polymerizable compound other than the oxetane compound (A) and the epoxy compound (B). Specific examples thereof include an aliphatic monoepoxy compound and an alicyclic monoepoxy compound.

[0050] The content of the polymerizable compound in the curable composition (1) is preferably 80 to 100 parts by mass, more preferably 90 to 99.5 parts by mass, and even more preferably 95 to 99 parts by mass, relative to 100 parts by mass of the total mass of the curable composition (1). When the content of the polymerizable compound is within the above range, migration of the dichroic dye contained in the polarizing film to the first cured product layer can be more effectively suppressed.

[0051] The curable composition usually contains a polymerization initiator for initiating polymerization. The polymerization initiator may be a photopolymerization initiator (e.g., a photocationic polymerization initiator or a photoradical polymerization initiator) or a thermal polymerization initiator. For example, when the curable composition contains the oxetane compound (A) or the epoxy compound (B) as a polymerizable compound, it is preferable to use a photocationic polymerization initiator as the polymerization initiator.

[0052] A cationic photopolymerization initiator generates cationic species or Lewis acids when irradiated with active energy rays such as visible light, ultraviolet light, X-rays, or electron beams, and initiates the polymerization reaction of a cationic polymerizable compound. Cationic photopolymerization initiators act catalytically with light, so they can initiate polymerization. The compound has excellent storage stability and workability even when mixed with an active compound. Examples of the compound that generates a cationic species or a Lewis acid upon irradiation with active energy rays include onium salts such as aromatic iodonium salts and aromatic sulfonium salts, aromatic diazonium salts, and iron-arene complexes.

[0053] The aromatic iodonium salt is a compound having a diaryliodonium cation, and a typical example of the cation is a diphenyliodonium cation. The aromatic sulfonium salt is a compound having a triarylsulfonium cation, and a typical example of the cation is a triphenylsulfonium cation or a 4,4'-bis(diphenylsulfonio)diphenylsulfide cation. The aromatic diazonium salt is a compound having a diazonium cation, and a typical example of the cation is a benzenediazonium cation. The iron-arene complex is typically a cyclopentadienyliron(II) arene cation complex salt.

[0054] The cations shown above are paired with anions (negative ions) to form photocationic polymerization initiators. The anions that make up photocationic polymerization initiators include special phosphorus anions [(Rf) n PF 6-n ] - , hexafluorophosphate anion PF6 - , hexafluoroantimonate anion SbF6 - , pentafluorohydroxyantimonate anion SbF5(OH) - , hexafluoroarsenate anion AsF6 - , tetrafluoroborate anion BF4 - , tetrakis(pentafluorophenyl)borate anion B(C6F5)4 - Among them, from the viewpoint of the curability of the polymerizable compound and the safety of the obtained cured layer, a photocationic polymerization initiator is preferably a special phosphorus anion [(Rf) n PF 6-n ] - , hexafluorophosphate anion PF6 - It is preferable that:

[0055] The cationic photopolymerization initiator may be used alone or in combination of two or more different types. Among them, aromatic sulfonium salts are preferred because they have ultraviolet absorption properties even in the wavelength region around 300 nm, and therefore have excellent curing properties and can provide a cured product with good mechanical strength and adhesive strength.

[0056] The content of the polymerization initiator in the curable composition (1) is typically 0.5 to 10 parts by mass, preferably 6 parts by mass or less, and more preferably 3 parts by mass or less, per 100 parts by mass of the polymerizable compound. When the content of the polymerization initiator is within this range, the polymerizable compound can be sufficiently cured, and the resulting cured product can be provided with a cured layer having high mechanical strength and adhesive strength. On the other hand, if the amount is excessively large, the product from the photocationic polymerization initiator may react with the hydroxyl groups of the polyvinyl alcohol constituting the polarizing film, potentially reducing the optical performance of the polarizing film.

[0057] In the present invention, the curable composition (1) may contain, if necessary, additives commonly used in curable compositions, such as an ion trapping agent, an antioxidant, a chain transfer agent, a polymerization accelerator (such as a polyol), a sensitizer, a sensitization aid, a light stabilizer, a tackifier, a thermoplastic resin, a filler, a flow control agent, a plasticizer, an antifoaming agent, a leveling agent, a silane coupling agent, a dye, an antistatic agent, and an ultraviolet absorber.

[0058] Examples of sensitizers include photosensitizers. Photosensitizers are compounds that exhibit a maximum absorption at a wavelength longer than the maximum absorption wavelength of the cationic photopolymerization initiator and promote the polymerization initiation reaction caused by the cationic photopolymerization initiator. Photosensitizer assistants are compounds that further promote the action of the photosensitizer. Depending on the type of protective film, it is preferable to incorporate such a photosensitizer or even a photosensitizer assistant. By incorporating these photosensitizers and photosensitizer assistants, a cured product with desired performance can be formed even when a film with low UV transmittance is used.

[0059] The photosensitizer is preferably a compound that exhibits maximum absorption at wavelengths longer than 380 nm, such as the anthracene compounds described below. 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diisopropoxyanthracene, 9,10-dibutoxyanthracene, 9,10-dipentyloxyanthracene, 9,10-dihexyloxyanthracene, 9,10-bis(2-methoxyethoxy)anthracene, 9,10-bis(2-ethoxyethoxy)anthracene, 9,10-bis(2-butoxyethoxy)anthracene, 9,10-bis(3-butoxypropoxy)anthracene, 2-methyl- or 2-ethyl-9,10-dimethoxyanthracene, 2-methyl- or 2-ethyl-9,10-diethoxyanthracene, 2-methyl- or 2-ethyl-9,10-dipropoxyanthracene, 2-methyl- or 2-ethyl-9,10-diisopropoxyanthracene, 2-methyl- or 2-ethyl-9,10-dibutoxyanthracene, 2-methyl- or 2-ethyl-9,10-dipentyloxyanthracene, 2-methyl- or 2-ethyl-9,10-dihexyloxyanthracene.

[0060] The curable composition (1) is obtained by mixing a polymerizable compound, a polymerization initiator, and, if necessary, additives. The first cured product layer can be formed by applying the curable composition (1) onto a polarizing film, or onto a first protective film if one is used, and curing the applied curable composition by irradiating it with active energy rays such as ultraviolet rays or electron beams.

[0061] Various coating methods can be used to apply the curable composition (1), such as a doctor blade, a wire bar, a die coater, a comma coater, or a gravure coater. Examples of light sources used to cure the curable composition (1) include light sources of active energy rays. The light source of active energy rays may be any light source that generates, for example, ultraviolet rays, electron beams, or X-rays. Light sources having an emission distribution with a wavelength of 400 nm or less are particularly preferred, and examples thereof include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0062] The light irradiation intensity when curing the curable composition (1) varies depending on the composition, but the light irradiation intensity in the wavelength region effective for activating the polymerization initiator is 0.1 to 1000 mW / cm. 2 If the light irradiation intensity during curing of the curable composition (1) is too low, it will take a long time for the reaction to proceed sufficiently, and conversely, if the light irradiation intensity is too high, the heat radiated from the lamp and the heat generated during polymerization of the curable composition (1) may cause deterioration of the attached film. The light irradiation time during curing of the curable composition (1) is controlled for each composition and is not particularly limited, but the integrated light amount, expressed as the product of the light irradiation intensity and the light irradiation time, is preferably 10 to 5000 mJ / cm. 2 It is preferable to set the integrated light amount so that: If the integrated light amount is too small, the generation of active species derived from the polymerization initiator may be insufficient, resulting in insufficient curing. If the integrated light amount is too large, the irradiation time becomes very long, which is disadvantageous for improving productivity.

[0063] When the curable composition is cured by irradiation with active energy rays, it is preferable to perform the curing under conditions that do not deteriorate the various functions of the optical laminate, such as the degree of polarization, transmittance, and hue of the polarizing film, and the transparency of the various films that constitute the protective film and optical layer.

[0064] In the optical laminate of the present invention, the thickness of the first cured material layer is not particularly limited, but is preferably 0.1 to 15 μm, more preferably 0.5 to 10 μm, and even more preferably 0.5 to 7 μm. When the thickness of the first cured material layer is equal to or greater than the lower limit, migration of the dichroic dye can be effectively suppressed, and when the thickness is equal to or less than the upper limit, the curable composition can be sufficiently cured.

[0065] The optical laminate of the present invention exhibits a 30% increase in absorbance of the first cured material layer, exhibiting relatively low absorptivity for the dichroic dye. While migration of dichroic dyes can typically be accelerated by external moisture penetration in high-temperature, high-humidity environments, the optical laminate of the present invention effectively inhibits migration of the dichroic dye contained in the polarizing film to the first cured material layer. Therefore, even in high-temperature, high-humidity environments, corrosion of the conductive layer can be effectively prevented and optical performance can be maintained. Furthermore, when the adhesive layer constituting the optical laminate contains an ionic compound, for example, as an antistatic agent, the ionic compound present in the adhesive layer may penetrate the protective film constituting the optical laminate and migrate to the polarizing film, where it may interact with the dichroic dye in the polarizing film, thereby degrading the optical performance of the optical laminate. The optical laminate of the present invention, having the first cured material layer between the polarizing film and the adhesive layer, effectively inhibits migration of the ionic compound from the adhesive layer, thereby preventing degradation of the optical performance of the optical laminate. The first cured product layer also serves as an adhesive layer that bonds the polarizing film to the protective film or the pressure-sensitive adhesive layer, which can prevent degradation of the optical performance of the optical laminate, especially in the case of a protective film that is easily permeated by ionic compounds and the like.

[0066] [Adhesive layer] The adhesive constituting the adhesive layer can be any conventionally known adhesive without any particular limitation, and can be, for example, an adhesive having an acrylic resin, a rubber resin, a urethane resin, a silicone resin, a polyvinyl ether resin, or the like as a base polymer. Energy ray-curable adhesives, thermosetting adhesives, or the like may also be used. Among these, adhesives having an acrylic resin as a base polymer, which is excellent in transparency, adhesive strength, reworkability, weather resistance, heat resistance, and the like, are preferred.

[0067] In the present invention, when the adhesive layer contains an acrylic resin, the acrylic resin is not particularly limited, and any conventionally known acrylic resin can be used. In particular, from the viewpoints of adhesiveness and reworkability, it is preferable that the adhesive layer contained in the optical laminate of the present invention contains the following acrylic resin (P).

[0068] The acrylic resin (P) is a compound represented by the following formula (III): [ka] [In the formula, R a represents a hydrogen atom or a methyl group, and R b represents an alkyl group having 1 to 14 carbon atoms which may be substituted with an alkoxy group having 1 to 10 carbon atoms. The acrylic resin has as its main component a structural unit derived from a (meth)acrylic acid alkyl ester (P1) represented by the following formula: and further contains a structural unit derived from an unsaturated monomer (P2) having a polar functional group (hereinafter, sometimes referred to as a "polar functional group-containing monomer"). In this specification, (meth)acrylic acid means either acrylic acid or methacrylic acid, and the "(meth)" in (meth)acrylate and the like has the same meaning.

[0069] Examples of the (meth)acrylic acid alkyl ester (P1) represented by formula (III) include linear acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, and lauryl acrylate; branched acrylic acid alkyl esters such as isobutyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; linear methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, and lauryl methacrylate; branched methacrylic acid alkyl esters such as isobutyl methacrylate, 2-ethylhexyl methacrylate, and isooctyl methacrylate; 2-methoxyethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl methacrylate, and ethoxymethyl methacrylate. Among these, n-butyl acrylate is preferred, and specifically, it is preferred that n-butyl acrylate accounts for 50 mass% or more of the total amount of all monomers constituting the acrylic resin (P). These (meth)acrylic acid alkyl esters (P1) may be used either alone or in combination of different types.

[0070] In the polar functional group-containing monomer (P2), examples of the polar functional group include a free carboxyl group, a hydroxyl group, an amino group, an epoxy group, and other heterocyclic groups. The polar functional group-containing monomer (P2) is preferably a (meth)acrylic acid-based compound having a polar functional group. Examples of such monomers include unsaturated monomers having a free carboxyl group, such as acrylic acid, methacrylic acid, and β-carboxyethyl acrylate; unsaturated monomers having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2- or 3-chloro-2-hydroxypropyl (meth)acrylate, and diethylene glycol mono(meth)acrylate; unsaturated monomers having a heterocyclic group, such as acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, and 2,5-dihydrofuran; and unsaturated monomers having an amino group other than the heterocyclic ring, such as N,N-dimethylaminoethyl (meth)acrylate. These polar functional group-containing monomers may be used alone or in combination.

[0071] The polar functional group-containing monomer (P2) is preferably an unsaturated monomer having a hydroxyl group. In addition to the unsaturated monomer having a hydroxyl group, it is also effective to use an unsaturated monomer having another polar functional group, for example, an unsaturated monomer having a free carboxyl group, in combination.

[0072] In the acrylic resin (P), the structural units derived from the (meth)acrylic acid alkyl ester (P1) represented by the formula (III) are, for example, 50 to 100 parts by mass relative to 100 parts by mass of all structural units constituting the acrylic resin (P). The structural units derived from the polar functional group-containing monomer (P2) are, for example, 0.1 to 20 parts by mass relative to 100 parts by mass of all structural units constituting the acrylic resin (P).

[0073] The acrylic resin (P) may contain structural units derived from monomers other than the (meth)acrylic acid alkyl ester (P1) represented by the formula (III) and the polar functional group-containing monomer (P2). Examples of such structural units include structural units derived from an unsaturated monomer (P3) having one olefinic double bond and at least one aromatic ring in the molecule (hereinafter sometimes referred to as an "aromatic ring-containing monomer"), structural units derived from a (meth)acrylic acid ester having an alicyclic structure in the molecule, structural units derived from a styrene-based monomer, structural units derived from a vinyl-based monomer, and structural units derived from a monomer having multiple (meth)acryloyl groups in the molecule.

[0074] The unsaturated monomer (aromatic ring-containing monomer) (P3) having one olefinic double bond and at least one aromatic ring in the molecule is preferably one having a (meth)acryloyl group as the group containing the olefinic double bond. Examples thereof include benzyl (meth)acrylate and neopentyl glycol benzoate (meth)acrylate, among which the monomer represented by the formula (IV): [ka] [wherein R3 represents a hydrogen atom or a methyl group, n is an integer of 1 to 8, and R4 represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an aralkyl group having 7 to 11 carbon atoms, or an aryl group having 6 to 10 carbon atoms] An aromatic ring-containing (meth)acrylic compound represented by the following formula is preferred.

[0075] Examples of alkyl groups having 1 to 9 carbon atoms include methyl, butyl, nonyl, etc. Examples of aralkyl groups having 7 to 11 carbon atoms include benzyl, phenethyl, naphthylmethyl, etc. Examples of aryl groups having 6 to 10 carbon atoms include phenyl, tolyl, naphthyl, etc.

[0076] Examples of the aromatic ring-containing (meth)acrylic compound represented by formula (IV) include 2-phenoxyethyl (meth)acrylate, 2-(2-phenoxyethoxy)ethyl (meth)acrylate, (meth)acrylic acid ester of ethylene oxide-modified nonylphenol, 2-(o-phenylphenoxy)ethyl (meth)acrylate, etc. These aromatic ring-containing monomers may be used alone or in combination of different types. Among these, 2-phenoxyethyl (meth)acrylate (a compound in which R4 = H and n = 1 in the formula (IV)), 2-(o-phenylphenoxy)ethyl (meth)acrylate (a compound in which R4 = o-phenyl and n = 1 in the formula (IV)), or 2-(2-phenoxyethoxy)ethyl (meth)acrylate (a compound in which R4 = H and n = 2 in the formula (IV)) is suitable as one of the aromatic ring-containing monomers (P3) constituting the acrylic resin (P).

[0077] The alicyclic structure in the structural unit derived from a (meth)acrylic acid ester having an alicyclic structure in the molecule is a cycloparaffin structure having a carbon number of usually 5 or more, preferably 5 to 7. Specific examples of acrylic acid esters having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, α-ethoxycyclohexyl acrylate, and cyclohexylphenyl acrylate. Specific examples of methacrylic acid esters having an alicyclic structure include isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, cyclododecyl methacrylate, methylcyclohexyl methacrylate, trimethylcyclohexyl methacrylate, tert-butylcyclohexyl methacrylate, and cyclohexylphenyl methacrylate.

[0078] Specific examples of styrene-based monomers include, in addition to styrene, alkyl styrenes such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; and further, nitrostyrene, acetyl styrene, methoxy styrene, and divinyl benzene.

[0079] Specific 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; vinylidene halides such as vinylidene chloride; nitrogen-containing aromatic vinyls such as vinylpyridine, vinylpyrrolidone, and vinylcarbazole; conjugated diene monomers such as butadiene, isoprene, and chloroprene; and acrylonitrile, methacrylonitrile, and the like.

[0080] Specific examples of monomers having multiple (meth)acryloyl groups in the molecule include monomers having two (meth)acryloyl groups in the 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 the molecule, such as trimethylolpropane tri(meth)acrylate.

[0081] The monomers other than the (meth)acrylic acid alkyl ester (P1) represented by formula (III) and the polar functional group-containing monomer (P2) can be used alone or in combination of two or more. When contained in the pressure-sensitive adhesive, the structural units derived from the monomers other than the (meth)acrylic acid alkyl ester (P1) and the polar functional group-containing monomer (P2) in the acrylic resin (P) are usually 0 to 30 parts by mass per 100 parts by mass of the total of all structural units constituting the acrylic resin (P).

[0082] The resin component constituting the pressure-sensitive adhesive composition may contain two or more acrylic resins containing structural units derived from the (meth)acrylic acid alkyl ester (P1) represented by formula (III) and the polar functional group-containing monomer (P2). The acrylic resin (P) may also be mixed with a different acrylic resin, such as an acrylic resin containing structural units derived from the (meth)acrylic acid alkyl ester of formula (III) but not containing a polar functional group. The amount of the acrylic resin (P) containing structural units derived from the (meth)acrylic acid alkyl ester (P1) represented by formula (III) and the polar functional group-containing monomer (P2) may be, for example, 70 parts by mass or more per 100 parts by mass of the total amount of acrylic resins contained in the pressure-sensitive adhesive layer.

[0083] The acrylic resin (P), which is a copolymer of a monomer mixture containing a (meth)acrylic acid alkyl ester (P1) represented by formula (III) and a polar functional group-containing monomer (P2), preferably has a weight-average molecular weight (Mw) of 1,000,000 to 2,000,000, as determined by gel permeation chromatography (GPC) in terms of standard polystyrene. A weight-average molecular weight (Mw) in this range in terms of standard polystyrene improves adhesion under high-temperature and high-humidity conditions, reduces the likelihood of peeling or lifting between the conductive layer and the adhesive layer, and improves reworkability. Furthermore, even if the polarizing film changes in size, the adhesive layer tends to follow and fluctuate accordingly. For example, when the optical laminate is attached to a liquid crystal cell, there is no difference in brightness between the periphery and center of the liquid crystal cell, and white spots and color unevenness tend to be suppressed.

[0084] The molecular weight distribution, represented by the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn, is preferably in the range of 3 to 7. When the molecular weight distribution Mw / Mn is in the range of 3 to 7, defects such as white spots can be suppressed even when the liquid crystal display panel or liquid crystal display device is exposed to high temperatures.

[0085] From the viewpoint of developing adhesiveness, the acrylic resin (P) preferably has a glass transition temperature in the range of −10 to −60° C. The glass transition temperature of a resin can generally be measured by a differential scanning calorimeter.

[0086] The acrylic resin (P) can be produced by various known methods, such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. In producing the acrylic resin (P), a polymerization initiator is usually used. The content of the polymerization initiator is preferably 0.001 to 5 parts by mass relative to 100 parts by mass of the total of all monomers used in producing the acrylic resin.

[0087] The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator. Examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone. Examples of the thermal polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 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 peroxide. Examples of the polymerization initiator include organic peroxides such as 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. Redox initiators using a peroxide in combination with a reducing agent can also be used as the polymerization initiator.

[0088] Solution polymerization is a particularly preferred method for producing the acrylic resin (P). A specific example of solution polymerization involves mixing the desired monomers and an organic solvent, adding a thermal polymerization initiator under a nitrogen atmosphere, and stirring for 3 to 10 hours at 40 to 90°C, preferably 50 to 80°C. To control the reaction, the monomers and the thermal polymerization initiator may be added continuously or intermittently during polymerization, or may be added in a dissolved state in an 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.

[0089] The adhesive layer included in the optical laminate of the present invention is preferably formed by combining an acrylic resin (P) and a crosslinking agent. Examples of crosslinking agents include compounds that react with structural units derived from the polar functional group-containing monomer (P2) in the acrylic resin (P) to crosslink the acrylic resin. Specific examples include isocyanate-based compounds, epoxy-based compounds, aziridine-based compounds, and metal chelate-based compounds. Of these, isocyanate-based compounds, epoxy-based compounds, and aziridine-based compounds have at least two functional groups in the molecule that can react with the polar functional groups in the acrylic resin (P).

[0090] The isocyanate compound is a compound having at least two isocyanato groups (-NCO) in the molecule, and examples thereof include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. Adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, as well as dimers, trimers, and the like of isocyanate compounds, can also be used as crosslinking agents for adhesives. Two or more isocyanate compounds can also be used in combination.

[0091] The epoxy compound is a compound having at least two epoxy groups in the molecule, and examples thereof include bisphenol A 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-xylylenediamine, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, etc. Two or more epoxy compounds can also be used in combination.

[0092] Aziridine compounds are compounds that have at least two three-membered ring skeletons, each consisting of one nitrogen atom and two carbon atoms, also known as ethyleneimines, within the molecule. Examples 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.

[0093] Examples of metal chelate compounds include compounds in which acetylacetone or ethyl acetoacetate is coordinated with a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, or zirconium.

[0094] Among these crosslinking agents, isocyanate compounds, particularly xylylene diisocyanate, tolylene diisocyanate, or hexamethylene diisocyanate, or adducts obtained by reacting these isocyanate compounds with polyols such as glycerol or trimethylolpropane, or dimers, trimers, etc. of these isocyanate compounds, or mixtures of these isocyanate compounds, are preferably used. In particular, when the polar functional group-containing monomer (P2) has a polar functional group selected from a free carboxyl group, a hydroxyl group, an amino group, and an epoxy group, it is preferable to use at least one isocyanate compound as the crosslinking agent. Among these, preferred isocyanate compounds include tolylene diisocyanate, an adduct obtained by reacting tolylene diisocyanate with a polyol, a dimer of tolylene diisocyanate, and a trimer of tolylene diisocyanate, as well as hexamethylene diisocyanate, an adduct obtained by reacting hexamethylene diisocyanate with a polyol, a dimer of hexamethylene diisocyanate, and a trimer of hexamethylene diisocyanate.

[0095] In the adhesive layer constituting the optical laminate of the present invention, the crosslinking agent may be, for example, 0.01 to 10 parts by mass relative to 100 parts by mass of the acrylic resin (P). When the amount of the crosslinking agent is within the above range, the durability of the adhesive layer tends to be improved, and white spots on the liquid crystal display panel become less noticeable. This is preferable because it tends to be

[0096] In the present invention, it is preferable that the adhesive constituting the adhesive layer contains a silane compound, and it is particularly preferable that the silane compound be contained in the acrylic resin before the crosslinking agent is blended in. Since the silane compound improves adhesive strength to glass, by including the silane compound, high adhesive strength to the display panel can be ensured.

[0097] Examples of silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, and 3-glycidoxypropylethoxydimethylsilane. These silane compounds may be used alone or in combination of two or more.

[0098] The silane-based compound may be a silicone oligomer type. When the silicone oligomer is expressed in the form of a (monomer)-(monomer) copolymer, for example, the following can be mentioned: mercaptopropyl group-containing copolymers such as 3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer, and 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer; mercaptomethyl group-containing copolymers such as mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, and mercaptomethyltriethoxysilane-tetraethoxysilane copolymer; methacryloyloxypropyl group-containing copolymers such as 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; acryloyloxypropyl group-containing copolymers such as 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; vinyl group-containing copolymers such as vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetraethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinylmethyldimethoxysilane-tetraethoxysilane copolymer, vinylmethyldiethoxysilane-tetramethoxysilane copolymer, and vinylmethyldiethoxysilane-tetraethoxysilane copolymer; Amino group-containing copolymers such as 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer.

[0099] These silane compounds are often liquids. The amount of the silane compound in the adhesive may be, for example, 0.01 to 10 parts by mass relative to 100 parts by mass of the acrylic resin (P) (the total amount when two or more types are used). When the amount of the silane compound relative to 100 parts by mass of the acrylic resin (P) is within the above range, this is preferable because it improves the adhesion between the adhesive layer and the substrate (or liquid crystal cell), and also tends to suppress bleeding of the silane compound from the adhesive layer.

[0100] The adhesive layer may contain an ionic compound. The ionic compound can function as an antistatic agent. In particular, when the acrylic resin (P) contains an aromatic ring-containing (meth)acrylic compound represented by the formula (IV) where n in formula (IV) is 2 or greater, this is effective in suppressing whiteout. By incorporating an ionic compound into an adhesive containing an acrylic resin copolymerized with this monomer, it is possible to impart good antistatic properties while also imparting a whiteout suppression effect. The ionic compound referred to here is a compound that exists as a combination of a cation and an anion. The cation and the anion may each be inorganic or organic. However, from the viewpoint of compatibility with the acrylic resin (P), it is preferable that at least one of the cation and the anion is an ionic compound containing an organic group.

[0101] Examples of inorganic cations that constitute ionic compounds include lithium cations [Li + ], sodium cation [Na + ], potassium cation [K + ], cesium cation [Cs + ] and other alkali metal ions; beryllium cation [Be 2+ ], magnesium cation [Mg 2+ ], calcium cation [Ca 2+ Among these, from the viewpoint of metal corrosion resistance, lithium cations [Li + ], potassium cation [K + ] or sodium cation [Na + From the viewpoint of durability, it is preferable to use potassium cations [K + It is more preferable to use

[0102] Examples of organic cations constituting the ionic compound include pyridinium cations represented by the following formula (V) and quaternary ammonium cations represented by the following formula (VI).

[0103] [ka]

[0104] In formula (V), R5 to R9 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 10 represents an alkyl group having 1 to 16 carbon atoms. 11 represents an alkyl group having 1 to 12 carbon atoms, and R 12 , R 13 and R 14 each independently represents an alkyl group having 6 to 12 carbon atoms.

[0105] The pyridinium cation represented by the formula (V) preferably has a total carbon number of 8 or more, particularly 10 or more, from the viewpoint of compatibility with the acrylic resin (P). The total carbon number is preferably 36 or less, more preferably 30 or less. Among the pyridinium cations represented by the formula (V), one in which R7 bonded to the carbon atom at the 4-position of the pyridine ring is an alkyl group, and R5, R6, R8, and R9 bonded to the other carbon atoms of the pyridine ring are each a hydrogen atom is a preferred cation.

[0106] Specific examples of the pyridinium cation represented by formula (V) include N-methyl-4-hexylpyridinium cation, N-butyl-4-methylpyridinium cation, N-butyl-2,4-diethylpyridinium cation, N-butyl-2-hexylpyridinium cation, N-hexyl-2-butylpyridinium cation, N-hexyl-4-methylpyridinium cation, N-hexyl-4-ethylpyridinium cation, N-hexyl-4-butylpyridinium cation, N-octyl-4-methylpyridinium cation, N-octyl-4-ethylpyridinium cation, and N-octylpyridinium cation.

[0107] From the viewpoint of compatibility with the acrylic resin (P), the ammonium cation represented by the formula (VI) preferably has a total carbon number of 20 or more, more preferably 22 or more, and more preferably 36 or less, more preferably 30 or less.

[0108] Specific examples of the tetraalkylammonium cation represented by formula (VI) include tetrahexylammonium cation, tetraoctylammonium cation, tributylmethylammonium cation, trihexylmethylammonium cation, trioctylmethylammonium cation, tridecylmethylammonium cation, trihexylethylammonium cation, and trioctylethylammonium cation.

[0109] On the other hand, examples of anions that constitute ionic compounds include chloride anions [Cl - ], bromide anion [Br - ], iodide anion [I - ], tetrachloroaluminate anion [AlCl 4- ], heptachlorodialuminate anion [Al2Cl7 - ], tetrafluoroborate anion [BF4 - ], hexafluorophosphate anion [PF6 - ], perchlorate anion [ClO4 - ], nitrate anion [NO3 - ], acetate anion [CH3COO - ], trifluoroacetate anion [CF3COO - ], methanesulfonate anion [CH3SO3 - ], trifluoromethanesulfonate anion [CF3SO3 - ], bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - ], tris(trifluoromethanesulfonyl)methanide anion [(CF3SO2)3C - ], hexafluoroarsenate anion [AsF6 - ], hexafluoroantimonate anion [SbF6 - ], hexafluoroniobate anion [NbF6 - ], hexafluorotantalate anion [TaF6 - ], (poly)hydrofluorofluoride anion [F(HF) n -](n is about 1 to 3), thiocyanate anion [SCN - ], dicyanamide anion [(CN)2N - ], perfluorobutanesulfonate anion [C4F9SO3 - ], bis(pentafluoroethanesulfonyl)imide anion [(C2F5SO2)2N - ], perfluorobutanoate anion [C3F7COO - ], (trifluoromethanesulfonyl)(trifluoromethanecarbonyl)imide anion [(CF3SO2)(CF3CO)N - ] etc.

[0110] Specific examples of the ionic compound can be appropriately selected from the combinations of cations and anions described above. Specific examples of the ionic compound that is a combination of a cation and anion include lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium iodide (lithium iodide), lithium bis(pentafluoroethanesulfonyl)imide, lithium tris(trifluoromethanesulfonyl)methanide, sodium bis(trifluoromethanesulfonyl)imide, sodium bis(pentafluoroethanesulfonyl)imide, sodium tris(trifluoromethanesulfonyl)methanide, potassium bis(trifluoromethanesulfonyl)imide, potassium bis(pentafluoroethanesulfonyl)imide, potassium tris(trifluoromethanesulfonyl)methanide, N-methyl-4-hexylpyridinium bis(trifluoromethanesulfonyl)imide, N-butyl-2-methylpyridinium bis(trifluoromethanesulfonyl)imide, and N-hexyl-4-methylpyridinium. Bis(trifluoromethanesulfonyl)imide, N-octyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide, N-methyl-4-hexylpyridinium hexafluorophosphate, N-butyl-2-methylpyridinium hexafluorophosphate, N-hexyl-4-methylpyridinium hexafluorophosphate, N-octyl-4-methylpyridinium hexafluorophosphate, N-methyl-4-hexylpyridinium perchlorate, N-butyl-2-methylpyridinium perchlorate, N-hexyl-4-methylpyridinium perchlorate, N-octyl-4-methylpyridinium perchlorate, tetrahexylammonium bis(trifluoromethanesulfonyl)imide, tributylmethylammonium bis(trifluoromethanesulfonyl)imide, trihexylmethylammonium bis(trifluoromethanesulfonyl)imide, trioctylmethylammonium Bis(trifluoromethanesulfonyl)imide, tetrahexylammonium hexafluorophosphate, tributylmethylammonium hexafluorophosphate, trihexylmethylammoniumExamples thereof include hexafluorophosphate, trioctylmethylammonium hexafluorophosphate, tetrahexylammonium perchlorate, tributylmethylammonium perchlorate, trihexylmethylammonium perchlorate, and trioctylmethylammonium perchlorate.

[0111] These ionic compounds can be used alone or in combination of two or more. When an ionic compound is contained, the amount thereof may be, for example, 0.1 to 10 parts by mass relative to 100 parts by mass of the acrylic resin (P).

[0112] In the present invention, the adhesive layer may further contain a crosslinking catalyst, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, a resin other than an acrylic resin, or the like. It is also useful to blend a UV-curable compound such as a multifunctional acrylate and a photoinitiator into the adhesive, and then irradiate the adhesive with UV light after forming the adhesive layer to cure it, thereby producing a harder adhesive layer. This creates a second crosslinked structure within the adhesive, improving durability during heat resistance tests and the like. Furthermore, by using a crosslinking catalyst in combination with a crosslinking agent in the adhesive, the adhesive layer can be prepared in a short maturation period. In the resulting optical laminate, lifting or peeling between the adhesive layer and the first cured layer or the first protective film, as well as foaming within the adhesive layer, can be suppressed, and reworkability may also be improved.

[0113] Examples of the crosslinking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resins, and melamine resins. When an amine compound is blended as a crosslinking catalyst in the pressure-sensitive adhesive, an isocyanate compound is preferred as the crosslinking agent.

[0114] Furthermore, the adhesive layer may contain fine particles to provide light scattering properties. The adhesive layer may also contain antioxidants and ultraviolet absorbers. Examples of ultraviolet absorbers include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, and nickel complex salt compounds.

[0115] The adhesive layer can be provided, for example, by preparing a solution of the adhesive as described above in an organic solvent, applying the solution to the film or layer (e.g., a polarizing film) to be laminated using a die coater or gravure coater, and then drying. Alternatively, the adhesive layer can be provided by transferring a sheet of the adhesive formed on a release-treated plastic film (called a separate film) to the film or layer to be laminated. The thickness of the adhesive layer is not particularly limited, but is preferably within the range of 2 to 40 μm, more preferably within the range of 5 to 35 μm, and even more preferably within the range of 10 to 30 μm.

[0116] The adhesive layer preferably has a storage modulus of 0.10 to 5.0 MPa at 23 to 80°C, more preferably 0.15 to 1.0 MPa. A storage modulus of 0.10 MPa or more at 23 to 80°C is preferred because it can prevent white spots due to shrinkage of the optical laminate when a liquid crystal display panel including the optical laminate is exposed to high temperatures. Furthermore, a storage modulus of 5 MPa or less is preferred because it is less likely to cause a decrease in durability due to a decrease in adhesive strength. Here, "exhibiting a storage modulus of 0.10 to 5.0 MPa at 23 to 80°C" means that the storage modulus is within this range at any temperature within this range. Since the storage modulus typically decreases gradually with increasing temperature, if the storage modulus at both 23°C and 80°C is within the above range, it can be assumed that the adhesive layer exhibits a storage modulus within this range at temperatures within this range. The storage modulus of the adhesive layer can be measured using a commercially available viscoelasticity measuring device, such as the "DYNAMIC ANALYZER RDA II" viscoelasticity measuring device manufactured by REOMETRIC.

[0117] [Conductive layer] The conductive layer included in the optical laminate of the present invention may be, for example, a conductive transparent metal oxide layer or a metal wiring layer. Such a conductive layer may be, for example, a layer containing at least one metal element selected from aluminum, copper, silver, iron, tin, zinc, platinum, nickel, molybdenum, chromium, tungsten, lead, titanium, palladium, indium, and alloys containing two or more of these metals. Among these, the conductive layer may be, from the viewpoint of conductivity, preferably a layer containing at least one metal element selected from aluminum, copper, silver, and gold. From the viewpoints of conductivity and cost, it may more preferably be a layer containing aluminum. Note that, in the case of a copper-containing layer, a blackening treatment may be performed to prevent light reflection. The blackening treatment is performed by oxidizing the surface of the conductive layer to precipitate CuO or CuO. The conductive layer may also be, for example, a layer containing metallic silver, ITO (tin-doped indium oxide), graphene, zinc oxide, or AZO (aluminum-doped zinc oxide).

[0118] The conductive layer (conductive layer 4 in FIGS. 1 and 2) is provided, for example, on a substrate (substrate X in FIGS. 1 and 2). A method for forming a conductive layer on a substrate includes, for example, sputtering. The substrate may be a transparent substrate constituting a liquid crystal cell included in a touch input element, or may be a glass substrate. The transparent substrate may be formed of, for example, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyethylene naphthalate, polyethersulfone, cyclic olefin copolymer, triacetyl cellulose, polyvinyl alcohol, polyimide, polystyrene, biaxially oriented polystyrene, or the like. The glass substrate may be formed of, for example, soda lime glass, low alkali glass, non-alkali glass, or the like. The conductive layer may be formed on the entire surface of the substrate, or on a part of it.

[0119] Examples of the conductive transparent metal oxide layer include transparent electrode layers such as ITO (tin-doped indium oxide) and AZO (aluminum-doped zinc oxide).

[0120] Examples of metal wiring layers include metal mesh, which is a layer of fine metal wiring lines, and layers in which metal nanoparticles or metal nanowires are added to a binder. The term "metal mesh" refers to a two-dimensional mesh structure formed from metal wiring lines. The shape of the openings (openings between wires or meshes) in the metal mesh is not particularly limited and may be, for example, polygonal (triangle, square, pentagon, hexagon, etc.), circular, elliptical, or irregular, and the openings may be the same or different. In a preferred embodiment, the openings in the metal mesh have the same shape, and are square or rectangular.

[0121] When the conductive layer is a metal wiring layer (particularly a metal mesh), the metal wiring may be arranged at predetermined intervals in the vertical and horizontal directions of the plane of the substrate X. In this case, the openings may be filled with a resin (adhesive, etc.), or the metal wiring layer may be embedded in the resin (adhesive, etc.). When a resin, etc. is used, the conductive layer (conductive layer 4) is composed of both the metal wiring and the resin (adhesive).

[0122] The line width of the metal wiring (particularly the metal mesh) is usually 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less, and is usually 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more. The line width of the metal wiring layer may be a combination of these upper and lower limit values, and is preferably 0.5 to 5 μm, and more preferably 1 to 3 μm.

[0123] The thickness of the conductive layer (conductive transparent metal oxide layer or metal wiring layer) is not particularly limited, but is usually 10 μm or less, preferably 3 μm or less, more preferably 1 μm or less, and particularly preferably 0.5 μm or less, and is usually 0.01 μm or more, preferably 0.05 μm or more, and more preferably 0.1 μm or more. The thickness of the conductive layer may be a combination of these upper and lower limits, and is preferably 0.01 to 3 μm, and more preferably 0.05 to 1 μm. Note that when the conductive layer is a metal wiring layer and the metal wiring layer is composed of both a resin (such as an adhesive) and metal wiring, the thickness of the conductive layer includes the thickness of the resin.

[0124] The method for preparing the conductive layer is not particularly limited, and the conductive layer may be formed by lamination of a metal foil, or by vacuum deposition, sputtering, wet coating, ion plating, inkjet printing, gravure printing, electrolytic plating, or electroless plating. Preferably, the conductive layer is formed by sputtering, inkjet printing, or gravure printing, and more preferably by sputtering.

[0125] The conductive layer (for example, a metal mesh) may have a function of generating a signal when the transparent substrate is touched in a touch panel, for example, and transmitting touch coordinates to an integrated circuit or the like.

[0126] The optical laminate of the present invention can be obtained by laminating (or bonding) a laminate in which the first cured product layer and the adhesive layer are laminated in this order on one side of the polarizing film to a conductive layer formed on a substrate.

[0127] Optical laminates having a conductive layer (e.g., a conductive transparent metal oxide layer, a metal wiring layer, etc.) are useful because they can be used in touch-input liquid crystal display devices having touch panel functions, etc. However, the dichroic dye (iodine) contained in the polarizing film migrates to the conductive layer, causing the conductive layer to easily corrode. In particular, when a metal wiring layer such as a metal mesh is used, the conductive layer is more susceptible to corrosion due to the narrow line width. However, the optical laminate of the present invention, which includes a first cured product layer, can effectively suppress the migration of the dichroic dye to the conductive layer and effectively prevent corrosion of the conductive layer.

[0128] [Polarizing film] The polarizing film constituting the optical laminate of the present invention is a film that has the function of extracting linearly polarized light from incident natural light, and in the present invention, it is a film obtained by incorporating a dichroic dye, preferably iodine, into a polyvinyl alcohol-based resin film and aligning it by adsorption. As the polyvinyl alcohol-based resin constituting the polyvinyl alcohol-based resin film, a saponified polyvinyl acetate-based resin can be used. Examples of polyvinyl acetate-based resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as copolymers of vinyl acetate with other monomers copolymerizable therewith (e.g., ethylene-vinyl acetate copolymer, etc.). Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group. Examples include:

[0129] The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, etc., modified with aldehydes can be used. The polymerization degree of the polyvinyl alcohol resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

[0130] A film formed from such a polyvinyl alcohol-based resin can be used as a raw film for a polarizing film. The method for forming a polyvinyl alcohol-based resin film is not particularly limited, and a conventionally known method can be used for film formation. The thickness of the raw film made of a polyvinyl alcohol-based resin is not particularly limited, but in consideration of ease of stretching, it is, for example, 10 to 150 μm, preferably 15 to 100 μm, and more preferably 20 to 80 μm.

[0131] A polarizing film is usually produced through the steps of uniaxially stretching such a polyvinyl alcohol-based resin film, dyeing the polyvinyl alcohol-based resin film with a dichroic dye to adsorb the dichroic dye, treating the polyvinyl alcohol-based resin film with the adsorbed dichroic dye with an aqueous boric acid solution, and washing the film with water after the treatment with the aqueous boric acid solution.

[0132] The uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before dyeing with a dichroic dye, simultaneously with dyeing, or after dyeing. When uniaxial stretching is performed after dyeing, it may be performed before or during the boric acid treatment. Uniaxial stretching can also be performed in these multiple stages. The uniaxial stretching may be performed uniaxially between rolls with different peripheral speeds, or uniaxially using a heated roll. The uniaxial stretching may be dry stretching in the atmosphere, or wet stretching in which the polyvinyl alcohol-based resin film is stretched in a swollen state using a solvent. The stretching ratio is preferably 8 times or less, more preferably 7.5 times or less, and even more preferably 7 times or less, from the viewpoint of suppressing deformation of the polarizing film. The stretching ratio is preferably 4.5 times or more, from the viewpoint of exhibiting the function as a polarizing film.

[0133] In the present invention, a method of dyeing a polyvinyl alcohol resin film by immersing it in an aqueous solution containing iodine and potassium iodide is usually employed. The iodine content in the aqueous solution is usually 0.01 to 1 part by mass per 100 parts by mass of water, and the potassium iodide content is usually 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually 20 to 40°C, and the immersion time in this aqueous solution (dyeing time) is usually 20 to 1,800 seconds.

[0134] The boric acid treatment after dyeing with iodine can be carried out by immersing the dyed polyvinyl alcohol-based resin film in a boric acid-containing aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is usually 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. In the present invention, the boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the boric acid-containing aqueous solution is usually 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 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.

[0135] The polyvinyl alcohol resin film after the boric acid treatment is usually washed with water. The washing can be carried out, for example, by immersing the boric acid-treated polyvinyl alcohol resin film in water. The water temperature in the washing is usually 5 to 40°C, and the immersion time is usually 1 to 120 seconds. After washing with water, the film is dried to obtain a polarized film. The drying can be carried out using a hot air dryer or a far-infrared heater. The drying temperature is usually 30 to 100°C, preferably 40 to 95°C, and more preferably 50 to 90°C. The drying time is usually 60 to 600 seconds, preferably 120 to 600 seconds.

[0136] In this way, the polyvinyl alcohol resin film is subjected to uniaxial stretching, dyeing with a dichroic dye, preferably iodine, and boric acid treatment to obtain a polarizing film, whose thickness can be, for example, 5 to 40 μm.

[0137] [Second cured material layer] The optical laminate of the present invention may include a second cured product layer composed of a cured product of a curable composition on the surface of the polarizing film opposite to the first cured product layer. The curable composition constituting the second cured product layer can be appropriately selected depending on the adhesiveness to the polarizing film and the second protective film, and may be a composition within the scope of the curable composition constituting the first cured product layer described above, or may be a photocurable adhesive known in the art. When a composition within the scope of the curable composition constituting the first cured product layer described above is used, the second cured product layer may be a curable composition having the same composition as the curable composition of the first cured product layer constituting the optical laminate, or a curable composition having a different composition may be used for the second cured product layer.

[0138] Examples of photocurable adhesives known in the art include mixtures of photocurable epoxy resins and photocationic polymerization initiators, etc., and mixtures of photocurable acrylic resins and photoradical polymerization initiators, etc. The curable composition that forms the cured product that constitutes the second cured product layer can be, for example, a photocurable adhesive containing a photocurable component and a photocationic polymerization initiator, as described in WO 2014 / 129368.

[0139] The second cured material layer can be formed by applying a curable composition constituting the second cured material layer to the surface of the optical laminate opposite to the surface on which the first cured material layer is laminated by a known method, and curing the composition. The curable composition constituting the second cured material layer can be applied by, for example, the same coating method as that used for applying the curable composition (1).

[0140] When a photocurable composition or a known photocurable adhesive is used as the curable composition constituting the second cured product layer, the curable composition or the curable adhesive is cured by irradiating it with active energy rays. The light source of the active energy rays is not particularly limited, but active energy rays having an emission distribution of wavelengths of 400 nm or less are preferred, and specific examples thereof include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0141] The light irradiation intensity of the curable composition constituting the second cured product layer can be appropriately selected depending on the composition of the curable composition and is not particularly limited. However, the irradiation intensity in the wavelength region effective for activating the polymerization initiator is preferably 0.1 to 1000 mW / cm. 2 The light irradiation time for the curable composition constituting the second cured product layer may be appropriately selected depending on the curable composition to be cured, and the integrated light amount, which is expressed as the product of the irradiation intensity and the irradiation time, is preferably 10 to 5000 mJ / cm. 2 It is set so that:

[0142] When the curable composition is cured by irradiation with active energy rays, it is preferable to perform the curing under conditions that do not deteriorate the various functions of the optical laminate, such as the polarization degree, transmittance, and hue of the polarizing film, and the transparency of the various films constituting the protective film and optical layer. The thickness of the second cured product layer is not particularly limited, but is usually 0.1 to 10 μm.

[0143] [Protective film] In one embodiment, the optical laminate of the present invention has a first protective film (7 shown in FIG. 2) laminated on one surface of the polarizing film via a first cured product layer. In another embodiment, the optical laminate of the present invention has a second protective film (6 shown in FIGS. 1 and 2) laminated on the other surface of the polarizing film (the surface opposite to the first cured product layer 2) via a second cured product layer. In one embodiment, the optical laminate of the present invention has the first protective film from the viewpoint of contributing to preventing shrinkage and expansion of the polarizing film and preventing deterioration of the polarizing film due to temperature, humidity, ultraviolet rays, etc. On the other hand, in one embodiment, from the viewpoint of reducing the thickness of the optical laminate, the optical laminate of the present invention does not include the first protective film. Since the first cured product layer in the present invention also contributes to preventing deterioration of the polarizing film in place of a protective film, from the viewpoint of achieving a good balance between preventing deterioration of the polarizing film and reducing the thickness of the optical laminate, it is preferable that the optical laminate of the present invention does not include the first protective film.

[0144] Materials for forming the protective film are preferably those with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. Examples include polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose-based polymers such as diacetyl cellulose and triacetyl cellulose; acrylic polymers such as polymethyl methacrylate; styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); and polycarbonate-based polymers. Other examples of polymers that can form the protective film include polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure, polyolefin-based polymers such as ethylene-propylene copolymers, amide-based polymers such as vinyl chloride-based polymers, nylon, and aromatic polyamides, imide-based polymers, sulfone-based polymers, polyethersulfone-based polymers, polyetheretherketone-based polymers, polyphenylene sulfide-based polymers, vinyl alcohol-based polymers, vinylidene chloride-based polymers, vinyl butyral-based polymers, arylate-based polymers, polyoxymethylene-based polymers, epoxy-based polymers, and blends of these polymers. The protective film can also be formed as a cured layer of a thermosetting or ultraviolet-curing resin such as an acrylic, urethane, acrylic urethane, epoxy, or silicone resin. Among these, those having a hydroxyl group reactive with an isocyanate crosslinking agent are preferred, and cellulose-based polymers are particularly preferred. In the optical laminate of the present invention, the first protective film and the second protective film may be made of the same material or different materials.

[0145] The moisture permeability of the second protective film is preferably 1200 g / (m) at a temperature of 23°C and a relative humidity of 55%. 2 24 hours) or less, and more preferably 800g / (m 2 24 hours) or less, and more preferably 600 g / (m 2 24 hours) or less, and particularly preferably 400 g / (m 2 24 hours) or less, and most preferably 200 g / (m 21 / 24 hours) or less. When the moisture permeability of the second protective film is the above value or less, it is possible to prevent the intrusion of moisture from the outside under high temperature and high humidity conditions and to prevent the accelerated migration of the dichroic dye (iodine) contained in the polarizing film, thereby more effectively preventing corrosion of the conductive layer and deterioration of the optical properties. On the other hand, because the optical laminate of the present invention has a first cured product layer, even if the second protective film does not satisfy the above moisture permeability, it is possible to suppress the migration of the dichroic dye (iodine) contained in the polarizing film and prevent deterioration of the conductive layer and deterioration of the optical properties.

[0146] The thickness of the protective film is not particularly limited, but the thickness of both the first protective film and the second protective film is usually 5 to 500 μm, preferably 1 to 300 μm, more preferably 5 to 200 μm, and even more preferably 10 to 100 μm. The protective film may also be composed of a protective film having an optical compensation function added thereto.

[0147] In the optical laminate of the present invention, the first cured product layer can effectively suppress the migration of the dichroic dye from the polarizing film to the adhesive layer and the migration of the ionic compound from the adhesive layer to the polarizing film, thereby broadening the range of materials that can be selected for the first protective film that constitutes the optical laminate. In other words, there is no need to use a protective film that is difficult for ionic compounds to permeate, and it is possible to construct the optical laminate using a protective film that is generally inexpensive and easily permeable to ionic compounds. This makes the optical laminate of the present invention advantageous from an industrial perspective, as it allows for lower production costs.

[0148] In the optical laminate of the present invention shown in Figures 1 and 2, a first cured product layer is laminated directly on a polarizing film, but a primer layer may be provided between the polarizing film and the first cured product layer, or between the first cured product layer and the pressure-sensitive adhesive layer. Examples of materials for forming the primer layer include various polymers such as urethane oligomers, metal oxide sols, and silica sols. The primer layer has a thickness thinner than the protective film, for example, 0.01 to 3 µm, preferably 0.1 to 2 µm, and more preferably 0.5 to 1 µm.

[0149] The optical laminate of the present invention may further include a protective film between the polarizing film and the first cured product layer via an adhesive layer. Examples of the protective film include the same protective films as the first protective film or second protective film exemplified above. The thickness of the protective film is also typically 5 to 500 μm, similar to the first protective film or second protective film.

[0150] In the optical laminate of the present invention, the first cured product layer can effectively prevent migration of the dichroic dye even without providing a protective film between the polarizing film and the first cured product layer. Therefore, the optical laminate of the present invention is preferably an embodiment in which the first cured product layer is laminated directly on the polarizing film, an embodiment in which the first cured product layer is laminated on the polarizing film via a primer layer, or an embodiment in which a pressure-sensitive adhesive layer is laminated on the first cured product layer via a primer layer.

[0151] The optical laminate of the present invention may further include an optical layer such as a retardation film, a viewing angle compensation film, or a brightness enhancement film, as needed. The optical layer in the optical laminate of the present invention can be formed using a material known in the art.

[0152] The optical laminate of the present invention can be produced by a known method. For example, a curable composition is applied to a second protective film to form a second curable composition layer, and a polarizing film is attached to the second curable composition layer to produce a laminate. In the case of an optical laminate that does not include a first protective film, a curable composition (1) is applied to a release film to form a first curable composition layer, and the polarizing film side of the laminate is attached to the coated surface. Next, the second curable composition layer and the first curable composition layer are cured by irradiating them with active energy rays such as ultraviolet rays or electron beams to form a second cured product layer and a first cured product layer. Thereafter, the release film is peeled off, and an adhesive layer is formed on the first cured product layer. Then, for example, an adhesive layer may be attached to a conductive layer laminated on a substrate. On the other hand, in the case of an optical laminate including a first protective film, a curable composition (1) is applied to the protective film to form a first cured composition layer, the polarizing film side of the laminate is attached to the coated surface, and then the first cured composition layer is cured by irradiating it with active energy rays such as ultraviolet light or electron beams to form a first cured product layer, and then an adhesive layer is formed on the first protective film. Then, for example, the adhesive layer may be attached to a conductive layer laminated on a substrate.

[0153] From the viewpoint of reducing thickness unevenness when the curable composition is applied and simultaneously reducing the thickness of the optical laminate, a laminate can be formed using a separate film (release film) as described above. For example, a laminate consisting of a polarizing film and a first cured product layer can be formed by laminating a separate film (release film) on one surface of the polarizing film via the first cured product layer, curing the first cured product layer with active energy rays or the like, and then peeling off the separate film (release film).

[0154] The present invention relates to an optical laminate having the above-described configuration, i.e., an optical laminate (in one embodiment, the optical laminate shown in Figs. 1 and 2 ) in which a first cured product layer composed of a cured product of a curable composition containing a polymerizable compound, an adhesive layer, and a conductive layer are laminated in this order on one surface of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, The polymerizable compound includes an oxetane compound having two or more oxetanyl groups, and the content of the oxetane compound is 40 parts by mass or more relative to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition. The inclusion of a predetermined amount of an oxetane compound having two or more oxetanyl groups enables the formation of a dense first cured layer with high crosslink density, thereby effectively suppressing migration of the dichroic dye (iodine) contained in the polarizing film to the first cured layer, thereby effectively preventing corrosion of the conductive layer and deterioration of optical performance due to the dichroic dye (iodine). In such an optical laminate, the increase in absorbance of the first cured layer may or may not be 30% or less. In a preferred embodiment, the oxetane compound having two or more oxetanyl groups is the oxetane compound (A) described above, and the components and contents (including preferred components and contents) contained in the curable composition that forms the cured product of the first cured layer are the same as those described above. The polarizing film, adhesive layer, and conductive layer contained in the optical laminate are also the same as those described above.

[0155] In the present invention, an optical laminate is provided in which a first cured material layer composed of a cured product of a curable composition containing a polymerizable compound, an adhesive layer, and a conductive layer are laminated in this order on one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, and the optical laminate has a water contact angle of 90° or more.Due to the excellent hydrophobicity of the first cured material layer, this optical laminate can effectively suppress the migration of the dichroic dye (iodine) even in a high-temperature, high-humidity environment in which migration of the dichroic dye becomes significant, and can effectively prevent corrosion of the conductive layer and deterioration of optical performance.

[0156] In the present invention, the water contact angle of the first cured material layer is, for example, 90° or more, preferably 95° or more, and more preferably 100° or more. When the water contact angle is equal to or greater than this value, migration of the dichroic dye to the first cured material layer can be effectively suppressed even under high temperature and high humidity conditions, and corrosion of the conductive layer and deterioration of optical performance can be effectively prevented.

[0157] In the present invention, an optical laminate is provided in which a first cured material layer composed of a cured product of a curable composition containing a polymerizable compound, an adhesive layer, and a conductive layer are laminated in this order on one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, and the optical laminate has a storage modulus of the first cured material layer at 30°C of 1500 MPa or more.Due to its relatively high crosslink density, this optical laminate has high barrier properties against the dichroic dye (iodine), effectively suppresses migration of the dichroic dye (iodine) to the first cured material layer, and can effectively prevent corrosion of the conductive layer and deterioration of optical performance.

[0158] The storage modulus of the first cured material layer at 30° C. is, for example, 1500 to 3500 MPa, preferably 1800 to 3500 MPa, more preferably 2000 to 3500 MPa, and even more preferably 2500 to 3500 MPa. When the storage modulus is at least the above lower limit, migration of the dichroic dye (iodine) to the first cured material layer can be more effectively suppressed, and corrosion of the conductive layer and deterioration of optical performance can be more effectively prevented.

[0159] In the present invention, an optical laminate is provided in which a first cured material layer composed of a cured product of a curable composition (1) containing a polymerizable compound, an adhesive layer, and a conductive layer are laminated in this order on one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, and the optical laminate has a glass transition temperature of 90°C or higher. Due to its relatively high crosslink density, the optical laminate has high barrier properties against the dichroic dye (iodine), effectively suppressing migration of the dichroic dye (iodine) to the first cured material layer and effectively preventing corrosion of the conductive layer and deterioration of optical performance.

[0160] The glass transition temperature of the first cured material layer is, for example, 90 to 180° C., preferably 100 to 180° C., more preferably 120 to 180° C., and even more preferably 150 to 180° C. When the elastic modulus is equal to or greater than the above lower limit, migration of the dichroic dye (iodine) to the first cured material layer can be more effectively suppressed, and corrosion of the conductive layer and deterioration of optical performance can be more effectively prevented. [Example]

[0161] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, "%" and "parts" represent "% by mass" and "parts by mass", respectively, unless otherwise specified.

[0162] [Example 1] 1. Preparation of the curable composition (I) constituting the first cured layer Curable compositions (I) of Production Examples 1 to 31 were prepared by mixing the components according to the formulations in Table 1 below.

[0163] 2. Evaluation of the absorbance increase rate of the first cured layer (evaluation of iodine ion absorption) The curable composition (I) of Production Example 1 was applied to one side of a 50 μm thick cycloolefin film (trade name "ZEONOR", manufactured by Zeon Corporation) using a bar coater so that the film thickness after curing would be approximately 30 μm. A 50 μm thick cycloolefin film (trade name "ZEONOR", manufactured by Zeon Corporation) was laminated to the coated surface to produce a laminate. An ultraviolet irradiation device with a belt conveyor (the lamp used was a "D bulb" manufactured by Fusion UV Systems) was used to irradiate the cycloolefin film side of the laminate with an integrated light intensity of 1000 mJ / cm from 280 nm to 320 nm. 2 The curable composition (I) was cured by irradiating with ultraviolet light so that the curable composition (I) was cured, thereby obtaining a laminate in which cycloolefin-based films were laminated on both sides of the first cured product layer. The cycloolefin-based films on both sides of the obtained laminate were peeled off, and the cured product of the curable composition (I) (first cured product layer) was isolated and used as an evaluation sample. The absorbance of the evaluation sample at 360 nm was measured using an ultraviolet-visible spectrophotometer ("UV2450" manufactured by Shimadzu Corporation), and this absorbance was defined as the absorbance before immersion. Next, the evaluation sample was immersed in a 50% potassium iodide aqueous solution for 100 hours in an atmosphere at a temperature of 23°C and a relative humidity of 60%. The evaluation sample was removed, the surface was wiped with pure water, and the absorbance at 360 nm was measured using a UV-visible spectrophotometer (Shimadzu Corporation, "UV2450"). This absorbance was used as the absorbance after immersion. Using the obtained absorbance, the increase rate of absorbance (%) was calculated as shown in the following formula. The results are shown in Table 1. Similarly, the increase rate of absorbance of each cured layer formed from the curable composition (I) of Production Examples 2 to 31 was determined. The results are shown in Table 1. Absorbance increase rate (%) = (absorbance after immersion (360 nm) - absorbance before immersion (360 nm)) / absorbance before immersion (360 nm) × 100 (1)

[0164] [Table 1]

[0165] The components in Table 1 are as follows: <Alicyclic epoxy compound (B2)> B2-1: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate ("Celloxide 2021P" (trade name), manufactured by Daicel Chemical Industries, Ltd.) B2-2: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol ("EHPE3150" (trade name), manufactured by Daicel Chemical Industries, Ltd.) <Aliphatic epoxy compound (B1)> B1-1: 1,4-butanediol diglycidyl ether ("EX-214" (trade name), manufactured by Nagase ChemteX Corporation) B1-2: Cyclohexanedimethanol diglycidyl ether ("EX-216" (trade name), manufactured by Nagase ChemteX Corporation) B1-3: Cyclohexanedimethanol diglycidyl ether ("EX-411" (trade name), manufactured by Nagase ChemteX Corporation) <Aromatic epoxy compound (B3)> B3-1: Resorcinol diglycidyl ether ("EX-201" (trade name), manufactured by Nagase ChemteX Corporation) B3-2: Bis-A type epoxy resin ("jER828EL" (trade name), manufactured by Mitsubishi Chemical Corporation) B3-3: 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-([2,3-epoxypropoxy]phenyl]ethyl]phenyl]propane ("TECHMORE VG3101L" (trade name), manufactured by Printec Co., Ltd.) <Oxetane compound (A)> A1-1: Bis(3-ethyl-3-oxetanylmethyl) ether ("OXT-221" (trade name), manufactured by Toagosei Co., Ltd.) A1-2: Xylylene bisoxetane ("OXT-121" (trade name), manufactured by Toagosei Co., Ltd.) <Oxetane compound (a)> a1-1: 2-ethylhexyloxetane ("OXT-212" (trade name), manufactured by Toagosei Co., Ltd., a compound having one oxetanyl group) a1-2: 3-ethyl-3-hydroxymethyloxetane ("OXT-101" (trade name), manufactured by Toagosei Co., Ltd., a compound having one oxetanyl group) <Acrylic compounds> P1-1: Tricyclodecane dimethanol diacrylate ("A-DCP" (trade name), manufactured by Shin-Nakamura Chemical Co., Ltd.) P1-2: Diacrylate of an acetal compound of hydroxypivalaldehyde and trimethylolpropane ("A-DOG (trade name)", manufactured by Shin-Nakamura Chemical Co., Ltd.) <Polymerization initiator> G1-1: Photocationic polymerization initiator: 50% solution of triarylsulfonium hexafluorophosphate in propylene carbonate ("CPI-100P" (trade name), manufactured by San-Apro Co., Ltd.) G1-2: Photoradical polymerization initiator: 2-hydroxy-2-methyl-1-phenyl-propan-1-one ("Darocur 1173" (trade name), manufactured by BASF Japan Ltd.) <Leveling agent> S1-1: Silicone leveling agent ("SH710" (trade name), manufactured by Dow Corning Toray Co., Ltd.)

[0166] 3. Preparation of Polarizing Film A 20 μm-thick polyvinyl alcohol film (Kuraray Co., Ltd., "Kuraray Poval KL318" (trade name): carboxyl-modified polyvinyl alcohol, average degree of polymerization approximately 2,400, saponification degree 99.9 mol% or more) was uniaxially stretched approximately 5 times by dry stretching. While still under tension, the film was immersed in pure water at 60°C for 1 minute, then immersed in an aqueous solution of iodine / potassium iodide / water in a mass ratio of 0.05 / 5 / 100 at 28°C for 60 seconds. It was then immersed in an aqueous solution of potassium iodide / boric acid / water in a mass ratio of 8.5 / 8.5 / 100 at 72°C for 300 seconds. The film was then washed in pure water at 26°C for 20 seconds and dried at 65°C to obtain a 7 μm-thick polarizing film (1) in which iodine was adsorbed and aligned in the polyvinyl alcohol film.

[0167] 4. Preparation of Water-based Adhesive A water-based adhesive (1) was prepared by mixing 100 parts by mass of pure water, 3.0 parts by mass of a polyvinyl alcohol film (Kuraray Co., Ltd., "Kuraray Poval KL318" (trade name): carboxyl group-modified polyvinyl alcohol), and 1.5 parts by mass of a water-soluble polyamide epoxy resin (Sumika Chemtex Co., Ltd., "Sumirez Resin 650" (trade name), working solution with a solids concentration of 30%). Note that the parts by mass of "Sumirez Resin 650" indicate the mass of the solids.

[0168] 5. Preparation of laminate (1) A water-based adhesive (1) was applied to one side of a polarizing film (1), and a triacetyl cellulose film (25KCHC-TC (trade name), 32 μm thick, manufactured by Toppan TOMOEGAWA Optical Films Co., Ltd.) with a hard-coated surface was saponified, and then the non-hard-coated side was attached to the polarizing film via the water-based adhesive (1). This was dried at 60°C for 6 minutes to produce a laminate (1) with a protective film on one side.

[0169] 6. Preparation of laminate (2) The curable composition (I) was applied to one side of a 50 μm thick cycloolefin film (trade name "ZEONOR", manufactured by Zeon Corporation) using a bar coater so that the film thickness after curing would be approximately 3 μm. The polarized film side of the laminate (1) was attached to the coated surface to produce a laminate. An ultraviolet irradiation device with a belt conveyor (the lamp used was a "D bulb" manufactured by Fusion UV Systems) was used to irradiate the cycloolefin film side of the laminate with an integrated light intensity of 200 mJ / cm from 280 nm to 320 nm. 2 The curable composition (I) was cured by irradiating it with ultraviolet light so that the curable composition (I) was cured, and then the cycloolefin-based film was peeled off to produce a laminate (2) consisting of a protective film / aqueous adhesive / polarizer film / curable composition (I) cured product (first cured product layer).

[0170] 7. Preparation of laminate (3) An organic solvent solution of an acrylic pressure-sensitive adhesive was prepared, and this organic solvent solution of the acrylic pressure-sensitive adhesive was coated using a die coater on the release-treated surface of a 38 μm-thick polyethylene terephthalate film (manufactured by Lintec Corporation under the trade name "SP-PLR382050"; hereinafter referred to as the release film) so that the dry thickness was 20 μm. The film was then dried to produce a sheet-like pressure-sensitive adhesive with a release film. The side of the sheet-like pressure-sensitive adhesive opposite the release film (the adhesive side) was then bonded to the first cured product layer side of laminate (2) using a laminator, and the laminate was then aged for 7 days at a temperature of 23°C and a relative humidity of 65% to obtain laminate (3) with a pressure-sensitive adhesive layer. This laminate had a release film bonded to the pressure-sensitive adhesive layer.

[0171] The acrylic adhesive contains the following: <Base polymer> Copolymer of butyl acrylate, methyl acrylate, acrylic acid and hydroxyethyl acrylate Isocyanate-based crosslinking agents Ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solids concentration 75%) ("Coronate L" (trade name), manufactured by Tosoh Corporation) <Silane coupling agent> 3-Glycidoxypropyltrimethoxysilane, liquid ("KBM-403" (trade name), manufactured by Shin-Etsu Chemical Co., Ltd.) <Antistatic Agent> 1-Hexylpyridinium hexafluorophosphate, a compound represented by the following formula (III): [ka]

[0172] 8.ITO Corrosion Evaluation An ITO film was formed on one side of alkali-free glass by sputtering to produce glass with an ITO film. This glass with an ITO thin film was cut into 25 mm x 25 mm pieces, and the center of the ITO thin film was measured using a low resistivity meter (Loresta AX MCP-T370, manufactured by Mitsubishi Chemical Analytech), and this was taken as the "initial resistance value." Next, laminate (3) was cut into 15 mm x 15 mm pieces, which were then bonded together so that the adhesive layer of the laminate (3) and the ITO thin film were in contact with each other, and then the laminate was heated at a temperature of 50°C and a pressure of 5 kg / cm. 2 The sample was autoclaved at 490.3 kPa (490.3 kPa) for 1 hour and then left in an environment at 23°C and 55% relative humidity for 24 hours. This was used as the evaluation sample. The evaluation sample was then placed in an environment at 80°C and 90% relative humidity for 72 hours, after which it was removed and the laminate (3) was peeled off. The ITO thin film was then washed with ethanol, and the "resistance value after durability testing" was measured using the same device as above. The ITO resistance increase rate was calculated using the following formula from the "initial resistance value" and "resistance value after durability testing" measured as described above, and the ITO corrosion resistance was evaluated using the following evaluation criteria. The results are shown in Table 2. The numbers in Table 2 indicate the increase rate values ​​in the following formula. Resistance increase rate (%) = (resistance after durability - initial resistance) / initial resistance x 100

[0173] ◎: Resistance increase rate is 20% or less ○: Resistance increase rate is more than 20% but less than 30% ×: Resistance increase rate is 30% or more

[0174] 9. Durability evaluation of laminate The laminate (3) was cut into a size of 30 mm x 30 mm, and after peeling off the release film, the adhesive layer side of the laminate (3) was attached to alkali-free glass ("EAGLE XG" manufactured by Corning Inc.) at a temperature of 50°C and a pressure of 5 kg / cm. 2 After autoclaving for 1 hour at 490.3 kPa (490.3 kPa), the laminate was left for 24 hours in an environment at 23°C and 55% relative humidity. Next, an optional accessory, a film holder with polarizing film, was attached to a UV-visible spectrophotometer (Shimadzu Corporation, "UV2450"), and the transmission spectra of the laminate in the transmission axis direction and absorption axis direction were measured in the wavelength range of 380 to 700 nm. Based on these measurements, the degree of polarization Py (unit: %) was calculated. This degree of polarization was designated as the initial Py. Furthermore, the degree of polarization after leaving the laminate for 24 hours in an environment at 80°C and 90% relative humidity was measured, and this degree of polarization was designated as the post-test Py. Based on these measurements, the change in degree of polarization ΔPy was calculated using the following formula. The results are shown in Table 1. ΔPy = post-test Py - initial Py

[0175] [Examples 2 to 22 and Comparative Examples 1 to 9] Using the curable compositions (I) of Production Examples 2 to 31, a first cured product layer and a laminate (3) were obtained in the same manner as in Example 1. Using the obtained laminate (3), the ITO resistance increase rate and the polarization degree change ΔPy were calculated in the same manner as in Example 1. The results are shown in Table 2. [Table 2]

[0176] As shown in Table 2, Examples 1 to 22 demonstrate that optical laminates in which the first cured product layer has an absorbance increase rate of 30% or less can effectively inhibit ITO corrosion even when placed under high-temperature, high-humidity conditions for a long period of time. In particular, Examples 4 to 20 and 22 demonstrate that optical laminates in which the first cured product layer has an absorbance increase rate of 20% or less can more effectively inhibit ITO corrosion. Furthermore, Examples 1 to 22 demonstrate that optical laminates in which the absorbance increase rate is 30% or less have excellent durability and can maintain optical performance even under high-temperature, high-humidity conditions.

[0177] As shown in Table 2, Examples 1 to 22 demonstrate that an optical laminate in which the first cured material layer contains an oxetane compound having two or more oxetanyl groups in an amount of 40 parts by mass or more per 100 parts by mass of the total amount of all polymerizable compounds can more effectively suppress corrosion of ITO. [Explanation of symbols]

[0178] REFERENCE SIGNS LIST 1...polarizing film, 2...first cured product layer, 3...adhesive layer, 4...conductive layer, 5...second cured product layer, 6...second protective film, 7...first protective film, 10...optical laminate, X...substrate

Claims

1. An optical laminate comprising a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, a first cured product layer formed from a cured product of a curable composition containing a polymerizable compound, an adhesive layer, and a conductive layer laminated in this order on one surface of the polarizing film, The first cured layer and the adhesive layer are adjacent to each other, the curable composition comprises the polymerizable compound, a photocationic polymerization initiator, and optionally an additive, the additive being at least one selected from the group consisting of a chain transfer agent, a polymerization accelerator, a sensitizer, a sensitization aid, a light stabilizer, a tackifier, a thermoplastic resin, a filler, a flow control agent, an antifoaming agent, a leveling agent, a silane coupling agent, a dye, an antistatic agent, and an ultraviolet absorber (however, excluding phosphorus-based compounds); the polymerizable compound comprises an oxetane compound (A) having two or more oxetanyl groups in the molecule, and at least one selected from an aliphatic epoxy compound (B1) having two or more epoxy groups in the molecule, an alicyclic epoxy compound (B2) having two or more epoxy groups in the molecule, and an aromatic epoxy compound (B3) having one or more aromatic rings in the molecule; When the curable composition contains an alicyclic epoxy compound (B2), the mass ratio (WB2 / WA) of the alicyclic epoxy compound (B2) to the oxetane compound (A) is 0.05 to 1.5; when the curable composition contains an aliphatic epoxy compound (B1), the mass ratio (WB1 / WA) of the aliphatic epoxy compound (B1) to the oxetane compound (A) is 0.1 to 0.5; and when the curable composition contains an aromatic epoxy compound (B3), the mass ratio (WB3 / WA) of the aromatic epoxy compound (B3) to the oxetane compound (A) is 0.1 to 1.5; The optical laminate, wherein the first cured product layer has an absorbance increase rate represented by the following formula (1) of 20% or less. Absorbance increase rate (%) = (Abs (360 nm) after immersion - Abs (360 nm) before immersion) / Abs (360 nm) before immersion × 100 (1) [In the formula, "Abs (360 nm) after immersion" refers to the absorbance at 360 nm after the cured product was immersed in a 50% aqueous potassium iodide solution for 100 hours in the atmosphere at a temperature of 23°C and a relative humidity of 60%, and "Abs (360 nm) before immersion" refers to the absorbance at 360 nm before the cured product was immersed in the 50% aqueous potassium iodide solution.]

2. 2. The optical laminate according to claim 1, wherein the first cured product layer has a thickness of 0.1 to 15 μm.

3. The optical laminate according to claim 1 or 2, wherein the cured product constituting the first cured product layer is a photocured product of a curable composition containing the polymerizable compound.

4. 4. The optical laminate according to claim 1, wherein a second cured material layer and a protective film are laminated on the surface of the polarizing film opposite to the first cured material layer.

5. The moisture permeability of the protective film is 1200 g / (m) at a temperature of 23°C and a relative humidity of 55%. ２ The optical laminate according to claim 4, wherein the curing time is 24 hours or less.

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