JP2023024446A - optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: 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

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to an optical laminate used for image display panels and the like.

BACKGROUND ART Conventionally, an optical laminate is known in which a protective film is laminated via an adhesive on one surface of a polarizing film in which a dichroic dye such as iodine is adsorbed and oriented on a polyvinyl alcohol-based resin film. As an adhesive used for forming such an optical laminate, for example, Patent Document 1 discloses a photo cationic curing adhesive containing an aliphatic epoxy, an alicyclic epoxy and/or oxetane, and a photopolymerization initiator. An adhesive (curable composition) is described, and a cured product obtained by curing the adhesive functions as an adhesive.

In recent years, transparent conductive films such as indium tin oxide (ITO) thin films have been widely used in display devices. For example, the transparent conductive film is formed on the opposite side of the transparent substrate constituting the liquid crystal cell from 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, and is antistatic. It is known to be layered. A transparent conductive film in which the transparent conductive film is formed on a transparent resin film is used as an electrode substrate of a touch panel. 2. Description of the Related Art Input devices using a combination of touch panels are becoming widely used.

JP 2008-063397 A

However, when a conductive layer such as an ITO layer is laminated via an adhesive layer on the polarizing film side of the optical laminate described in Patent Document 1, the dichroic dye contained in the polarizing film compares the adhesive layer. It is easily permeable to the target and may migrate to the conductive layer, which may cause malfunction such as poor sensing. Since the movement of the dichroic dye from such a polarizing film is particularly remarkable in a high temperature and high humidity environment, the dichroic dye contained in the polarizing film even in a high temperature and high humidity environment is transferred to the pressure-sensitive adhesive layer. There is a need for an optical laminate that can prevent deterioration of the conductive layer due to migration to the conductive layer via

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical laminate capable of effectively suppressing migration of a dichroic dye contained in a polarizing film to a conductive layer and preventing deterioration of the conductive layer.

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

The optical layered body of the present invention can suppress migration of the dichroic dye contained in the polarizing film to the conductive layer, and can effectively suppress corrosion of the conductive layer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a configuration that is one embodiment of an optical layered body of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a configuration that is one embodiment of an optical layered body of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. It should be noted 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 gist of the present invention.

The configuration of one embodiment of the optical layered body of the present invention will be described with reference to FIG. , and a conductive layer 4 are laminated in this order. If necessary, a protective film 6 may be provided on the opposite side of the polarizing film 1 from the first cured layer 5 with the second cured layer 5 interposed therebetween. Also, the conductive layer 4 of the optical stack 10 is laminated to the substrate X in the embodiment of FIG.

Moreover, the optical layered body of the present invention may have a first protective film 7 between the first cured layer 2 and the adhesive layer 3 . This embodiment is shown in FIG. If necessary, the optical laminate 10 may be provided with a second protective film 6 on the opposite side of the polarizing film 1 to the first cured layer 2 with the second cured layer 5 interposed therebetween. good. 2, the conductive layer 4 of the optical stack 10 is laminated to the substrate X. In the embodiment of FIG.
Hereinafter, each component of the optical layered body of the present invention will be described in detail.

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

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

Even if the first cured product layer is immersed in a 50% potassium iodide aqueous solution for 100 hours, the rate of increase in absorbance represented by the above formula (1) is 30% or less. This indicates that the absorption of iodine (dichroic dye) of the first cured product layer is relatively low. Therefore, the optical layered body of the present invention can effectively suppress the movement of iodine (dichroic dye) contained in the polarizing film to the first cured product layer, and the iodine (dichroic dye) can effectively suppress the movement of the iodine (dichroic dye). Corrosion of layers (eg ITO layers) can be prevented. Furthermore, the optical performance of the optical laminate can be maintained.

The absorbance increase rate 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 can be prevented. And it is possible to more effectively prevent deterioration of the optical performance of the optical layered body.

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. Resin compositions are preferred, and (meth)acrylate compounds, including epoxy acrylates and urethane acrylates, acrylamide compounds, oxetane compounds, and epoxy compounds are particularly preferred.

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. Therefore, the polymerizable compound is preferably a photocurable compound.

The polymerizable compound preferably contains an oxetane compound having two or more oxetanyl groups (oxetane rings) in the molecule (hereinafter sometimes referred to as "oxetane compound (A)").

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-ethyloxetane-3-yl)methoxy}methyl]benzene (also called xylylenebisoxetane), bis(3-ethyl- 3-oxetanylmethyl)ether and the like. These oxetane compounds (A) may be used alone or in combination of multiple different types. By containing the oxetane compound (A), it is possible to obtain a dense cured product having a high crosslink density. By providing a cured product layer with a high cross-linking density on one side of the polarizing film, it is possible to effectively suppress the movement of the dichroic dye from the polarizing film.

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 100 parts by mass as the total amount of all polymerizable compounds contained in the curable composition (1). is 50 parts by mass or more. Further, the content of the oxetane compound (A) is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, relative to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition (1). More preferably 70 parts by mass or less, particularly preferably 65 parts by mass or less. In addition, the content of the oxetane compound (A) may be a combination of these lower limit values and upper limit values, and is , preferably 40 to 65 parts by mass, more preferably 45 to 60 parts by mass.
In addition, the content of the oxetane compound (A) is, for example, 35 parts by mass or more, preferably 40 parts by mass or more, more preferably 45 parts by mass, with respect to 100 parts by mass of the total amount of the curable composition (1). That's it. When the content of the oxetane compound (A) is at least the above value, the 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 can be prevented. And it is possible to more effectively prevent deterioration of the optical performance of the optical layered body.

The polymerizable compound preferably further contains an epoxy compound (B). The epoxy compound is preferably (B1) an aliphatic epoxy compound having two or more epoxy groups (hereinafter sometimes referred to as "aliphatic epoxy compound (B1)"), (B2) 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, "aromatic epoxy compound (B3)”).

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 compounds such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, and neopentyl glycol diglycidyl ether. Epoxy compounds; trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, and other trifunctional or higher epoxy compounds.

When the aliphatic epoxy compound (B1) is included, from the viewpoint of adhesion between the polarizing film and the protective film or the adhesive layer, a bifunctional epoxy compound having two oxirane rings bonded to the aliphatic carbon atoms in the molecule. (Also referred to as an aliphatic diepoxy compound) is preferable, and an aliphatic diepoxy compound represented by the following formula (I) is more preferable. 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 a low viscosity and being easy to apply can be obtained.

式（Ｉ）中、Ｚは炭素数１～９のアルキレン基、炭素数３もしくは４のアルキリデン基、２価の脂環式炭化水素基、又は式－Ｃ_ｍＨ_２ｍ－Ｚ^１－Ｃ_ｎＨ_２ｎ－で示される２価の基を表す。－Ｚ^１－は、－Ｏ－、－ＣＯ－Ｏ－、－Ｏ－ＣＯ－、－ＳＯ_２－、－ＳＯ－又はＣＯ－を表し、ｍ及びｎは各々独立に１以上の整数を表す。ただし、ｍ及びｎの合計は９以下である。

In formula (I), Z is an alkylene group having 1 to 9 carbon atoms, an alkylidene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or the formula -C _m H _2m -Z ¹ -C _n H _2n- represents a divalent group. -Z ¹ - represents -O-, -CO-O-, -O-CO-, -SO ₂ -, -SO- or CO-, and m and n each independently represent an integer of 1 or more. However, the sum of m and n is 9 or less.

The divalent alicyclic hydrocarbon group may be, for example, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, such as a divalent residue represented by the following formula (I-1) is mentioned.

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 numbers; and diglycidyl ethers of alicyclic diols.

Diols (glycols) that can form the compound represented by formula (I) include 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, 1,9-nonanediol;
Oligoalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol;
Alicyclic diols such as cyclohexanediol and cyclohexanedimethanol are included.

In the present invention, as the aliphatic epoxy compound (B1), 1,4-butanediol diglycidyl ether, 1,6-hexanediol diol diol, 1,4-butanediol diglycidyl ether, and 1,6-hexanediol diol diol are used from the viewpoint that a curable composition having a low viscosity and being easy to apply can be obtained. Glycidyl ether and neopentyl glycol diglycidyl ether are preferred. 1,6-Hexanediol diglycidyl ether and pentaerythritol polyglycidyl ether are preferable in terms of maintaining optical performance. As the aliphatic epoxy compound (B1), one kind of aliphatic epoxy compound may be used alone, or a plurality of different kinds may be used in combination.

When the curable composition (1) contains an aliphatic epoxy compound (B1), the content of the aliphatic epoxy compound (B1) is relative to the total amount of 100 parts by mass of all polymerizable compounds contained in the curable composition. , preferably 1 to 40 parts by mass, more preferably 3 to 30 parts by mass, still more preferably 5 to 20 parts by mass, particularly 7 to 15 parts by mass. When the content of the aliphatic epoxy compound (B1) is within the above range, the curable composition (1) has a low viscosity and can be easily applied.

で示される構造における橋かけの酸素原子－Ｏ－を意味する。上記式（ａ）中、ｍは２～５の整数である。 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 attached to an alicyclic ring" is represented by the following formula (a):

means a bridging oxygen atom —O— in the structure represented by In the above formula (a), m is an integer of 2-5.

A compound in which two or more groups in the form of (CH ₂ ) _m in the above formula (a) with one or more hydrogen atoms removed are bonded to another chemical structure is an alicyclic epoxy compound (B2 ). One or more hydrogen atoms in (CH ₂ ) _m may optionally be substituted with a straight-chain alkyl group such as a methyl group or an ethyl group.

Among them, the glass transition temperature of the cured product is high, and from the viewpoint of excellent adhesion between the polarizing film and the protective film, the epoxycyclopentane structure [m = 3 in the above formula (a)] and the epoxycyclohexane structure An alicyclic epoxy compound having [m=4 in the above formula (a)] is preferable, and an alicyclic diepoxy compound represented by the following formula (II) is more preferable. When the curable composition (1) contains an alicyclic diepoxy compound represented by the following formula (II) as the compound (B2), the cured product layer after curing of the curable composition has high elasticity. , cracking due to heat shrinkage of the polarizing film can be suppressed.

式（ＩＩ）中、Ｒ^１及びＲ^２は各々独立に水素原子又は炭素数１～６のアルキル基を表し、前記アルキル基が炭素数３以上である場合は脂環式構造を有していてもよい。前記炭素数１～６のアルキル基は直鎖又は分枝アルキル基であってよく、脂環式構造を有するアルキル基としては、シクロプロピル基、シクロブチル基、シクロペンチル基等が挙げられる。

In formula (II), R ¹ and R ² each independently represent 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 has an alicyclic structure. good too. 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 cyclopropyl group, cyclobutyl group and cyclopentyl group.

のいずれかで示される２価の基を表す。
炭素数１～６のアルカンジイル基としては、例えば、メチレン基、エチレン基、プロパン－１，２－ジイル基等が挙げられる。 In formula (II), X is an oxygen atom, an alkanediyl group having 1 to 6 carbon atoms, or the following formulas (IIa) to (IId):

represents a divalent group represented by any one of
Examples of the alkanediyl group having 1 to 6 carbon atoms include methylene group, ethylene group, propane-1,2-diyl group and the like.

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

Examples of the compound represented by formula (II) include compounds A to G below. Chemical formulas A to G shown below correspond to compounds A to G, respectively.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate C: ethylenebis(3,4 - epoxy cyclohexane carboxylate)
D: bis (3,4-epoxycyclohexylmethyl) adipate E: bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate F: diethylene glycol bis (3,4-epoxycyclohexylmethyl ether)
G: ethylene glycol bis(3,4-epoxycyclohexyl methyl ether)

In the present invention, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate is more preferable as the alicyclic epoxy compound (B2) from the viewpoint of easy availability. Also, from the viewpoint of being able to effectively suppress corrosion of the conductive layer, a 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol is preferred. In particular 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate in combination with 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol. When used as the alicyclic epoxy compound (B2), the corrosion of the conductive layer can be more effectively suppressed. As the alicyclic epoxy compound (B2), one type of alicyclic epoxy compound may be used alone, or a plurality of different types may be used in combination.

When the curable composition (1) contains the alicyclic epoxy compound (B2), the content of the alicyclic epoxy compound (B2) is 100, the total amount of all polymerizable compounds contained in the curable composition (1). It is preferably 3 to 70 parts by mass, more preferably 10 to 60 parts by mass, still more preferably 20 to 55 parts by mass, and particularly preferably 25 to 50 parts by mass. 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 rapidly, and a cured product layer with sufficient hardness can be easily formed. .

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

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

Commercially available products can be used as the aromatic epoxy compound (B3). 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-1051, Oncoat EX-1010, Oncoat EX-1011, Oncoat 1012 (manufactured by Nagase ChemteX Corporation); company); HP4032, HP4032D, HP4700 (manufactured by DIC); ESN-475V (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.); Epicoat YX8800, jER828EL (manufactured by Mitsubishi Chemical Corporation); (manufactured by NOF Corporation); Epiclon N-665, Epiclon HP-7200 (manufactured by DIC Corporation); EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, XD-1000, NC-3000, EPPN- 501H, EPPN-501HY, EPPN-502H, NC-7000L (manufactured by Nippon Kayaku Co., Ltd.); , ADEKA RESIN EP-4000, ADEKA RESIN EP-4005, ADEKA RESIN EP-4100, ADEKA RESIN EP-4901 (manufactured by ADEKA); TECHMORE VG-3101L, EPOX-MKR710, EPOX-MKR151 (manufactured by Printec) mentioned.

By including the aromatic epoxy compound (B3) in the curable composition, the curable composition becomes a hydrophobic resin, and the resulting cured product layer also becomes hydrophobic. Therefore, it is possible to prevent moisture from entering from the outside under high temperature and high humidity conditions, and to effectively suppress migration of the dichroic dye (iodine) contained in the polarizing film.

When the curable composition (1) contains the aromatic epoxy compound (B3), the content of the aromatic epoxy compound (B3) is 100 mass of the total amount of all polymerizable compounds contained in the curable composition (1). parts by weight, preferably 1 to 70 parts by weight, more preferably 5 to 60 parts by weight, still more preferably 7 to 55 parts by weight, and particularly preferably 10 to 50 parts by weight. 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) to the cured product layer can be reduced.

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

The curable composition (1) may contain polymerizable compounds other than the oxetane compound (A) and the epoxy compound (B). Specific examples include aliphatic monoepoxy compounds and alicyclic monoepoxy compounds.

The content of the polymerizable compound contained in the curable composition (1) is preferably 80 to 100 parts by mass, more preferably 90 to 99 parts by mass, per 100 parts by mass of the total mass of the curable composition (1). 5 parts by mass, more preferably 95 to 99 parts by mass. When the content of the polymerizable compound is within the above range, it is possible to more effectively suppress the migration of the dichroic dye contained in the polarizing film to the first cured product layer.

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

Photocationic polymerization initiators generate cationic species or Lewis acids upon irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, or electron beams, and initiate the polymerization reaction of cationic polymerizable compounds. . Since the photocationic polymerization initiator acts catalytically with light, it is excellent in storage stability and workability even when mixed with a polymerizable compound. Examples of compounds that generate cationic species or Lewis acids 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.

An aromatic iodonium salt is a compound having a diaryliodonium cation, typically a diphenyliodonium cation. Aromatic sulfonium salts are compounds having a triarylsulfonium cation, and typical cations include triphenylsulfonium cations and 4,4'-bis(diphenylsulfonio)diphenylsulfide cations. An aromatic diazonium salt is a compound having a diazonium cation, typically a benzenediazonium cation. Also, the iron-arene complex is typically a cyclopentadienyl iron(II) arene cation complex salt.

The cations shown above are paired with anions (anions) to form photocationic polymerization initiators. Examples of anions constituting the photocationic polymerization initiator include a special phosphorus-based anion [(Rf) _n PF _6-n ] ⁻ , hexafluorophosphate anion PF ₆ ⁻ , hexafluoroantimonate anion SbF ₆ ⁻ , and pentafluorohydroxyantimonate. Examples include the anion SbF ₅ (OH) ⁻ , the hexafluoroarsenate anion AsF ₆ ⁻ , the tetrafluoroborate anion BF ₄ ⁻ , the tetrakis(pentafluorophenyl)borate anion B(C ₆ F ₅ ) ₄ ⁻ and the like. Among them, from the viewpoint of the curability of the polymerizable compound and the safety of the resulting cured product layer, the photocationic polymerization initiator is a special phosphorus-based anion [(Rf) _n PF _6-n ] ⁻ or a hexafluorophosphate anion PF ₆ ⁻ is preferably

A photocation polymerization initiator may be used individually by 1 type, or may be used in combination of multiple different types. Among them, aromatic sulfonium salts are preferable because they have ultraviolet absorption properties even in a wavelength region around 300 nm, and thus are excellent in curability and can provide a cured product having good mechanical strength and adhesive strength.

The content of the polymerization initiator in the curable composition (1) is usually 0.5 to 10 parts by mass, preferably 6 parts by mass or less, more preferably 3 parts by mass, relative to 100 parts by mass of the polymerizable compound. It is below the department. When the content of the polymerization initiator is within the above range, the polymerizable compound can be sufficiently cured, and high mechanical strength and adhesive strength can be imparted to the cured product layer composed of the obtained cured product. . 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, possibly deteriorating the optical performance of the polarizing film.

In the present invention, the curable composition (1) can contain additives commonly used in curable compositions, if necessary. Such additives include, for example, ion trapping agents, antioxidants, chain transfer agents, polymerization accelerators (such as polyols), sensitizers, sensitizing aids, light stabilizers, tackifiers, thermoplastic resins, , fillers, flow control agents, plasticizers, antifoaming agents, leveling agents, silane coupling agents, dyes, antistatic agents, ultraviolet absorbers and the like.

Examples of sensitizers include photosensitizers. A photosensitizer is a compound that exhibits a maximum absorption at a wavelength longer than the maximum absorption wavelength exhibited by a photocationic polymerization initiator and accelerates the polymerization initiation reaction by the photocationic polymerization initiator. A photosensitizer is a compound that further promotes the action of a photosensitizer. Depending on the type of the protective film, it is preferable to incorporate such a photosensitizer or a photosensitizing aid. By blending these photosensitizers and photosensitizing aids, it is possible to form a cured product having desired properties even when a film having low UV transmittance is used.

The photosensitizer is preferably a compound that exhibits maximum absorption for light with a wavelength longer than 380 nm, for example. Examples of such photosensitizers include 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.

The curable composition (1) is obtained by mixing a polymerizable compound, a polymerization initiator, and, if necessary, additives. For the first cured product layer, the curable composition (1) is applied on the polarizing film or on the first protective film when the first protective film is used, and active energy rays such as ultraviolet rays and electron beams are applied. It can be formed by curing the applied curable composition by irradiation.

Various coating methods such as doctor blade, wire bar, die coater, comma coater, and gravure coater can be used to apply the curable composition (1). A light source for curing the curable composition (1) includes a light source for active energy rays. The light source of the active energy ray may be one that generates ultraviolet rays, electron beams, X-rays, or the like, for example. In particular, a light source having an emission distribution at a wavelength of 400 nm or less is preferable, and examples 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, metal halide lamps, and the like.

The light irradiation intensity for curing the curable composition (1) differs 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 . is preferred. If the light irradiation intensity during curing of the curable composition (1) is too low, the time required for the reaction to proceed sufficiently increases. Conversely, if the light irradiation intensity is too high, the heat radiated from the lamp In addition, heat generation 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. It is preferable to set up to 5000 mJ/cm ² . If the cumulative amount of light is too small, generation of active species derived from the polymerization initiator may be insufficient, resulting in insufficient curing. On the other hand, if the integrated amount of light is too large, the irradiation time will be very long, which is disadvantageous for improving productivity.

In addition, when the curable composition is cured by irradiation with active energy rays, for example, the degree of polarization, transmittance and hue of the polarizing film, and the transparency of various films constituting the protective film and the optical layer. Curing is preferably carried out under conditions where various functions do not deteriorate.

In the optical laminate of the present invention, the thickness of the first cured product layer is not particularly limited, but is preferably 0.1 to 15 μm, more preferably 0.5 to 10 μm, and still more preferably 0.5 μm. ~7 μm. When the thickness of the first cured product layer is at least the lower limit, the movement of the dichroic dye can be effectively suppressed, and when it is at most the upper limit, the curable composition can be sufficiently cured. .

In the optical layered body of the present invention, the absorbance increase rate of the first cured product layer is 30%, and the absorption of the dichroic dye is relatively low. Normally, in a high-temperature and high-humidity environment, the migration of the dichroic dye can be accelerated by the intrusion of moisture from the outside. Movement to the layer can be effectively suppressed. Therefore, even in a high-temperature and high-humidity environment, the corrosion of the conductive layer can be effectively prevented, and the optical performance can be maintained. Furthermore, when the adhesive layer constituting the optical layered body contains an ionic compound as, for example, an antistatic agent, the ionic compound present in the adhesive layer transmits through the protective film constituting the optical layered body, and the polarized light is It can migrate into the film and cause interaction with the dichroic dye in the polarizing film, degrading the optical performance of the optical laminate. In the optical laminate of the present invention, since the first cured material layer exists between the polarizing film and the adhesive layer, it is possible to effectively suppress the migration of the ionic compound from the adhesive layer. It is possible to prevent deterioration of the optical performance of the body.
The first cured product layer also serves as an adhesive layer that bonds the polarizing film and the protective film or adhesive layer. In this case, deterioration of the optical performance of the optical layered body can be prevented even with a protective film through which an ionic compound or the like is easily transmitted.

[Adhesive layer]
As the adhesive constituting the adhesive layer, conventionally known adhesives can be used without particular limitation. An adhesive having as can be used. Alternatively, an energy ray-curable adhesive, a heat-curable adhesive, or the like may be used. Among these, a pressure-sensitive adhesive using an acrylic resin as a base polymer, which is excellent in transparency, adhesive strength, reworkability, weather resistance, heat resistance, etc., is preferable.

In the present invention, when the adhesive layer contains an acrylic resin, the acrylic resin is not particularly limited, and conventionally known resins can be used. Among them, from the viewpoint 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).

〔式中、Ｒ_ａは水素原子又はメチル基を表し、Ｒ_ｂは炭素数１～１０のアルコキシ基で置換されていてもよい炭素数１～１４のアルキル基を表す〕
で示される（メタ）アクリル酸アルキルエステル（Ｐ１）に由来する構造単位を主成分とし、さらに、極性官能基を有する不飽和単量体（Ｐ２）（以下、「極性官能基含有単量体」と称する場合がある）に由来する構造単位を含むアクリル樹脂である。
ここで、本明細書において、（メタ）アクリル酸とは、アクリル酸又はメタクリル酸のいずれでもよいことを意味し、この他、（メタ）アクリレートなどというときの「（メタ）」も同様の趣旨である。 The acrylic resin (P) has the following formula (III):

[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 main component is a structural unit derived from a (meth)acrylic acid alkyl ester (P1) represented by, and an unsaturated monomer (P2) having a polar functional group (hereinafter, “polar functional group-containing monomer” It is an acrylic resin containing structural units derived from
Here, in this specification, (meth)acrylic acid means either acrylic acid or methacrylic acid, and "(meth)" when referring to (meth)acrylate has the same meaning. is.

Examples of (meth)acrylic acid alkyl esters (P1) represented by formula (III) include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, and lauryl acrylate. linear alkyl acrylates; branched alkyl acrylates such as isobutyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-methacrylate linear alkyl methacrylates such as butyl, n-octyl methacrylate, and lauryl methacrylate; branched alkyl methacrylates, such as isobutyl methacrylate, 2-ethylhexyl methacrylate, and isooctyl methacrylate; acrylic acid 2-methoxyethyl, ethoxymethyl acrylate, 2-methoxyethyl methacrylate, ethoxymethyl methacrylate and the like.
Among these, n-butyl acrylate is preferable, and specifically, n-butyl acrylate is preferably 50% by mass or more with respect to the total amount of all monomers constituting the acrylic resin (P). These (meth)acrylic acid alkyl esters (P1) may be used alone, or may be used in combination of a plurality of different types.

In the polar functional group-containing monomer (P2), polar functional groups include free carboxyl groups, hydroxyl groups, amino groups, heterocyclic groups such as epoxy groups, and the like. The polar functional group-containing monomer (P2) is preferably a (meth)acrylic compound having a polar functional group. Examples thereof include unsaturated monomers having free carboxyl groups such as acrylic acid, methacrylic acid, and β-carboxyethyl acrylate; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, ( 2- or 3-chloro-2-hydroxypropyl meth)acrylate, and unsaturated monomers having a hydroxyl group such as diethylene glycol mono(meth)acrylate; Unsaturated monomers having a heterocyclic group such as furyl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, and 2,5-dihydrofuran and unsaturated monomers having amino groups different from heterocyclic rings such as N,N-dimethylaminoethyl (meth)acrylate. Each of these polar functional group-containing monomers may be used alone, or a plurality of different types may be used.

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 together an unsaturated monomer having another polar functional group, such as an unsaturated monomer having a free carboxyl group.

In the acrylic resin (P), the structural unit derived from the (meth)acrylic acid alkyl ester (P1) represented by the formula (III) is and, for example, 50 to 100 parts by mass. The structural unit derived from the polar functional group-containing monomer (P2) is, for example, 0.1 to 20 parts by weight per 100 parts by weight of the total amount of all structural units constituting the acrylic resin (P).

The acrylic resin (P) contains a structural unit derived from a monomer different from the (meth)acrylic acid alkyl ester (P1) and the polar functional group-containing monomer (P2) represented by the formula (III). You can Examples of these include unsaturated monomers (P3) having one olefinic double bond and at least one aromatic ring in the molecule (hereinafter sometimes referred to as "aromatic ring-containing monomers"). ), structural units derived from (meth)acrylic acid esters having an alicyclic structure in the molecule, structural units derived from styrene monomers, structural units derived from vinyl monomers , a structural unit derived from a monomer having a plurality of (meth)acryloyl groups in the molecule, and the like.

〔式中、Ｒ_３は水素原子又はメチル基を表し、ｎは１～８の整数であり、Ｒ_４は水素原子、炭素数１～９のアルキル基、炭素数７～１１のアラルキル基又は炭素数６～１０のアリール基を表す〕
で示される芳香環含有（メタ）アクリル化合物が好ましい。 An unsaturated monomer having one olefinic double bond and at least one aromatic ring in the molecule (aromatic ring-containing monomer) (P3) is a group containing an olefinic double bond (meth ) Those having an acryloyl group are preferred. Examples thereof include benzyl (meth)acrylate, neopentyl glycol benzoate (meth)acrylate and the like, among which formula (IV):

[In the formula, R ₃ represents a hydrogen atom or a methyl group, n is an integer of 1 to 8, R ₄ is a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an aralkyl group having 7 to 11 carbon atoms, or a carbon represents an aryl group of numbers 6 to 10]
An aromatic ring-containing (meth)acrylic compound represented by is preferred.

Examples of alkyl groups having 1 to 9 carbon atoms include methyl, butyl and nonyl. Aralkyl groups having 7 to 11 carbon atoms include benzyl, phenethyl and naphthylmethyl. The aryl group having 6 to 10 carbon atoms includes phenyl, tolyl, naphthyl and the like.

Examples of the aromatic ring-containing (meth)acrylic compound represented by formula (IV) include 2-phenoxyethyl (meth)acrylate, 2-(2-phenoxyethoxy)ethyl (meth)acrylate, ethylene oxide-modified nonylphenol (meth) ) acrylate, 2-(o-phenylphenoxy)ethyl (meth)acrylate, and the like. These aromatic ring-containing monomers may be used alone, or may be used in combination of a plurality of different types. Among these, 2-phenoxyethyl (meth)acrylate [compound of R ₌ H and n = 1 in the formula (IV)], 2-(o-phenylphenoxy)ethyl (meth)acrylate [the formula In (IV), R ₄ = o-phenyl, n = 1], or 2-(2-phenoxyethoxy)ethyl (meth)acrylate [In formula (IV), R ₄ = H, n = 2 compound] is suitable as one of the aromatic ring-containing monomers (P3) constituting the acrylic resin (P).

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

Specific examples of styrenic monomers include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, and octylstyrene. halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; and nitrostyrene, acetylstyrene, methoxystyrene, divinylbenzene, and the like.

Specific examples of vinyl monomers include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; halogenated 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; Lonitrile and the like can be mentioned.

Specific examples of monomers having multiple (meth)acryloyl groups in the molecule include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonane Diol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate have two (meth)acrylates in the molecule. ) a monomer having an acryloyl group; a monomer having three (meth)acryloyl groups in the molecule such as trimethylolpropane tri(meth)acrylate.

The monomers different from the (meth)acrylic acid alkyl ester (P1) and the polar functional group-containing monomer (P2) represented by formula (III) may be used alone or in combination of two or more. can. When contained in the adhesive, in the acrylic resin (P), the structural unit derived from a monomer different from the (meth)acrylic acid alkyl ester (P1) and the polar functional group-containing monomer (P2) is the acrylic resin It is usually 0 to 30 parts by mass with respect to 100 parts by mass as the total amount of all structural units constituting (P).

The resin component constituting the adhesive composition is an acrylic resin containing structural units derived from the (meth)acrylic acid alkyl ester (P1) and the polar functional group-containing monomer (P2) represented by the formula (III). Two or more types may be included. Further, the acrylic resin (P) is mixed with a different acrylic resin, for example, an acrylic resin having a structural unit derived from the (meth)acrylic acid alkyl ester of the formula (III) and not containing a polar functional group. may be used. The acrylic resin (P) containing structural units derived from the (meth)acrylic acid alkyl ester (P1) and the polar functional group-containing monomer (P2) represented by formula (III) is the acrylic resin contained in the adhesive layer. For example, it may be 70 parts by mass or more with respect to 100 parts by mass of the total amount of.

The acrylic resin (P), which is a copolymer of a monomer mixture containing a (meth)acrylic acid alkyl ester (P1) represented by the formula (III) and a polar functional group-containing monomer (P2), is a gel permeate. It is preferable that the weight average molecular weight Mw in terms of standard polystyrene by fraction chromatography (GPC) is in the range of 1,000,000 to 2,000,000. When the weight average molecular weight in terms of standard polystyrene is within the above range, the adhesiveness is improved under high temperature and high humidity conditions, and the possibility of peeling or floating between the conductive layer and the adhesive layer tends to decrease. Furthermore, reworkability tends to improve. In addition, even if the dimensions of the polarizing film change, the adhesive layer tends to follow the dimensional change and fluctuate. There is no difference between the brightness and the brightness of the image, and white spots and color unevenness tend to be suppressed.

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

Further, the acrylic resin (P) preferably has a glass transition temperature in the range of -10 to -60°C from the viewpoint of exhibiting adhesiveness. The glass transition temperature of a resin can generally be measured with a differential scanning calorimeter.

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

A thermal polymerization initiator, a photopolymerization initiator, or the like is used as the polymerization initiator. Examples of photopolymerization initiators include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone and the like. Examples of thermal polymerization initiators include 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-methylpropio azo compounds such as 2,2′-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide organic compounds such as oxides, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl) peroxide. Peroxides; inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide; A redox initiator using a peroxide and a reducing agent in combination may also be used as the polymerization initiator.

A solution polymerization method is particularly preferable as the method for producing the acrylic resin (P). A specific example of the solution polymerization method will be explained. Desired monomers and an organic solvent are mixed, a thermal polymerization initiator is added under a nitrogen atmosphere, and the reaction is carried out at 40 to 90° C., preferably 50 to 80° C. for 3 hours. A method of stirring for up to 10 hours can be mentioned. Moreover, in order to control the reaction, the monomers and the thermal polymerization initiator may be added continuously or intermittently during the polymerization, or may be added in a state of being dissolved in an organic solvent. Examples of organic solvents 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; acetone, methyl ethyl ketone, and methyl isobutyl. Ketones such as ketones and the like can be used.

The adhesive layer contained in the optical layered body of the present invention is preferably composed of a combination of an acrylic resin (P) and a cross-linking agent. The cross-linking agent is, for example, a compound that reacts with structural units derived from the polar functional group-containing monomer (P2) in the acrylic resin (P) to cross-link the acrylic resin. Specific examples include isocyanate-based compounds, epoxy-based compounds, aziridine-based compounds, metal chelate-based compounds, and the like. Among these, the isocyanate-based compound, epoxy-based compound and aziridine-based compound have at least two functional groups in the molecule capable of reacting with the polar functional group in the acrylic resin (P).

The isocyanate-based compound is a compound having at least two isocyanato groups (--NCO) in the molecule, such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, Hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate and the like. In addition, adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, and dimers, trimers, etc. of isocyanate compounds can also be used as cross-linking agents for adhesives. . A mixture of two or more isocyanate compounds can also be used.

Epoxy-based compounds are compounds having at least two epoxy groups in the molecule, and examples thereof include bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether. , 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N-diglycidylaniline, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis( N,N'-diglycidylaminomethyl)cyclohexane and the like. A mixture of two or more epoxy compounds can also be used.

Aziridine-based compounds are compounds having at least two 3-membered ring skeletons consisting of one nitrogen atom and two carbon atoms, also called ethyleneimine, in the molecule. 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, tetramethylolmethane tris-β-aziridinylpropionate and the like.

As metal chelate compounds, for example, polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium are coordinated with acetylacetone or ethyl acetoacetate. compound and the like.

Among these cross-linking agents, isocyanate compounds, especially xylylene diisocyanate, tolylene diisocyanate or hexamethylene diisocyanate, or adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, Dimers, trimers, etc. of these isocyanate compounds, mixtures of these isocyanate compounds, and the like are preferably used. Especially when the polar functional group-containing monomer (P2) has a polar functional group selected from free carboxyl groups, hydroxyl groups, amino groups and epoxy groups, it is preferable to use at least one isocyanate compound as a cross-linking agent. . Among the preferred isocyanate-based compounds are tolylene diisocyanate, an adduct obtained by reacting tolylene diisocyanate with a polyol, a dimer of tolylene diisocyanate, a trimer of tolylene diisocyanate, hexamethylene diisocyanate, and hexamethylene diisocyanate. is reacted with a polyol, a dimer of hexamethylene diisocyanate, and a trimer of hexamethylene diisocyanate.

In the adhesive layer constituting the optical layered body of the present invention, the cross-linking agent may be, for example, 0.01 to 10 parts by mass with respect to 100 parts by mass of the acrylic resin (P). When the amount of the cross-linking 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 tend to be less noticeable, which is preferable.

In the present invention, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer preferably contains a silane-based compound, and it is particularly preferable to allow the acrylic resin to contain the silane-based compound before blending the cross-linking agent. Since the silane-based compound improves the adhesive strength to glass, high adhesive strength to the display panel can be ensured by containing the silane-based compound.

Examples of silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-amino ethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane sidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethylsilane and the like. These silane compounds may be used alone or in combination of two or more.

The silane-based compound may be of the silicone oligomer type. Examples of silicone oligomers in the form of (monomer)-(monomer) copolymers include the following.
3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer, and 3-mercaptopropyltriethoxysilane-tetraethoxy Mercaptopropyl group-containing copolymers, such as silane copolymers;
mercaptomethyl, such as mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, and mercaptomethyltriethoxysilane-tetraethoxysilane copolymer; group-containing copolymers;
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 Copolymers containing methacryloyloxypropyl groups, such as 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;
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 acryloyloxypropyl group-containing copolymers, such as 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;
vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetraethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinyl group-containing copolymers such as vinylmethyldimethoxysilane-tetraethoxysilane copolymer, vinylmethyldiethoxysilane-tetramethoxysilane copolymer, and vinylmethyldiethoxysilane-tetraethoxysilane copolymer;
3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane Copolymers, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-aminopropylmethyldiethoxy and amino group-containing copolymers, such as silane-tetraethoxysilane copolymers.

These silane-based compounds are often liquid. The amount of the silane compound in the adhesive may be, for example, 0.01 to 10 parts by mass with respect 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-based compound relative to 100 parts by mass of the acrylic resin (P) is within the above range, it is preferable because the adhesion between the adhesive layer and the substrate (or liquid crystal cell) is improved, and the silane-based compound is removed from the adhesive layer. This is preferable because it tends to suppress bleed-out.

The adhesive layer may contain an ionic compound. Ionic compounds can function as antistatic agents. In particular, when the acrylic resin (P) contains an aromatic ring-containing (meth)acrylic compound represented by the formula (IV) and n in the formula (IV) is 2 or more, it is effective in suppressing white spots. By blending an ionic compound in a pressure-sensitive adhesive containing an acrylic resin copolymerized with this monomer, it is possible to impart good antistatic properties while imparting an effect of suppressing white spots. The ionic compound as used herein is a compound that exists as a combination of a cation and an anion, and the cation and anion may be inorganic or organic. From the viewpoint of compatibility, at least one of the cation and the anion is preferably an ionic compound containing an organic group.

Examples of inorganic cations constituting the ionic compound include alkali metal ions such as lithium cation [Li ⁺ ], sodium cation [Na ⁺ ], potassium cation [K ⁺ ], cesium cation [Cs ⁺ ]; beryllium cation [Be ²⁺ ], magnesium cation [Mg ²⁺ ], and calcium cation [Ca ²⁺ ]. Among them, lithium cation [Li ⁺ ], potassium cation [K ⁺ ] or sodium cation [Na ⁺ ] is preferably used from the viewpoint of metal corrosion resistance, and potassium cation [K ⁺ ] is preferably used from the viewpoint of durability. It is more preferable to use

Examples of organic cations constituting the ionic compound include pyridinium-based cations represented by the following formula (V): and quaternary ammonium cations represented by the following formula (VI).

In formula (V), R ₅ to R ₉ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₁₀ represents an alkyl group having 1 to 16 carbon atoms. In formula (VI), R ₁₁ represents an alkyl group having 1 to 12 carbon atoms, and R ₁₂ , R ₁₃ and R ₁₄ each independently represent an alkyl group having 6 to 12 carbon atoms.

The pyridinium-based cation represented by the above 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 number of carbon atoms is preferably 36 or less, more preferably 30 or less. Among the pyridinium-based cations represented by formula (V), R ₇ bonded to the 4-position carbon atom of the pyridine ring is an alkyl group, and R ₅ , R ₆ and R bonded to other carbon atoms of the pyridine ring One preferred cation is one in which ₈ and _R9 are each hydrogen atoms.

Specific examples of pyridinium-based cations 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, N-octylpyridinium cation and the like.

The ammonium cation represented by the above formula (VI) preferably has a total carbon number of 20 or more, more preferably 22 or more, from the viewpoint of compatibility with the acrylic resin (P). Also, the total number of carbon atoms is preferably 36 or less, more preferably 30 or less.

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, trioctylethylammonium cation, and the like.

On the other hand, examples of anions constituting ionic compounds include chloride anion [Cl ⁻ ], bromide anion [Br ⁻ ], iodide anion [I ⁻ ], tetrachloroaluminate anion [AlCl ⁴⁻ ], heptachlorodiene aluminate anion [Al ₂ Cl ₇ ⁻ ], tetrafluoroborate anion [BF ₄ ⁻ ], hexafluorophosphate anion [PF ₆ ⁻ ], perchlorate anion [ClO ₄ ⁻ ], nitrate anion [NO ₃ ⁻ ], acetate anion [CH ₃ COO ⁻ ], trifluoroacetate anion [CF ₃ COO ⁻ ], methanesulfonate anion [CH ₃ SO ₃ ⁻ ], trifluoromethanesulfonate anion [CF ₃ SO ₃ ⁻ ], bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ], tris(trifluoromethanesulfonyl)methanide anion [(CF ₃ SO ₂ ) ₃ C ⁻ ], hexafluoroarsenate anion [AsF ₆ ⁻ ], hexafluoroantimonate anion [ SbF ₆ ⁻ ], hexafluoroniobate anion [NbF ₆ ⁻ ], hexafluorotantalate anion [TaF ₆ ⁻ ], (poly)hydrofluorofluoride anion [F(HF) _n ⁻ ] (n is about 1 to 3 ), thiocyan anion [SCN ⁻ ], dicyanamide anion [(CN) ₂ N ⁻ ], perfluorobutanesulfonate anion [C ₄ F ₉ SO ₃ ⁻ ], bis(pentafluoroethanesulfonyl)imide anion [(C ₂ F ₅ SO ₂ ) ₂ N ⁻ ], perfluorobutanoate anion [C ₃ F ₇ COO ⁻ ], (trifluoromethanesulfonyl)(trifluoromethanecarbonyl)imide anion [(CF ₃ SO ₂ )(CF ₃ CO)N ⁻ ] etc. are mentioned.

Specific examples of the ionic compound can be appropriately selected from the above combinations of cations and anions. Specific ionic compounds that are combinations of cations and anions 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(pentafluoroethane) sulfonyl)imide, potassium tris(trifluoromethanesulfonyl)methanide, N-methyl-4-hexylpyridinium bis(trifluoromethanesulfonyl)imide, N-butyl-2-methylpyridinium bis(trifluoromethanesulfonyl)imide, 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, trihexylmethylammonium hexafluorophosphate, trioctyl methylammonium hexafluorophosphate, tetrahexylammonium perchlorate, tributylmethylammonium perchlorate, trihexylmethylammonium perchlorate, trioctylmethylammonium perchlorate and the like.

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

In the present invention, the adhesive layer may further contain crosslinking catalysts, weather stabilizers, tackifiers, plasticizers, softeners, dyes, pigments, inorganic fillers, resins other than acrylic resins, and the like. It is also useful to add an ultraviolet curable compound such as a polyfunctional acrylate and a photoinitiator to the adhesive, and to harden the adhesive layer by irradiating it with ultraviolet rays after forming the adhesive layer, thereby forming a harder adhesive layer. This materializes a second cross-linking structure in the adhesive and serves to improve durability during a heat resistance test. In addition, if a crosslinking catalyst is used together with a crosslinking agent in the adhesive, the adhesive layer can be prepared in a short period of aging, and in the resulting optical laminate, the adhesive layer and the first cured product layer or the first protective film It is possible to suppress the occurrence of floating and peeling between the adhesive layers and the occurrence of foaming in the adhesive layer, and the reworkability may be improved.

Examples of cross-linking catalysts include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resins, and melamine resins. . When blending an amine-based compound as a cross-linking catalyst with the pressure-sensitive adhesive, an isocyanate-based compound is suitable as the cross-linking agent.

Furthermore, it is also possible to form an adhesive layer exhibiting light scattering properties by containing fine particles. The adhesive layer may also contain an antioxidant, an ultraviolet absorber, or the like. UV absorbers include salicylic acid ester compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, nickel complex compounds, and the like.

The adhesive layer can be provided, for example, by making an organic solvent solution of the adhesive described above, applying it on a film or layer (e.g., polarizing film, etc.) to be laminated with a die coater, gravure coater, etc., and drying it. can be done. It can also be provided by a method of transferring a sheet-like pressure-sensitive adhesive formed on a release-treated plastic film (called a separate film) to a film or layer to be laminated. The thickness of the adhesive layer is not particularly limited, but it is preferably in the range of 2 to 40 μm, more preferably in the range of 5 to 35 μm, and even more preferably in the range of 10 to 30 μm. .

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 elastic modulus of 0.10 MPa or more at 23 to 80° C. is preferable because white spots due to contraction of the optical layered body can be suppressed when the liquid crystal display panel including the optical layered body is exposed to high temperature. Further, when the pressure is 5 MPa or less, deterioration in durability due to reduction in adhesive strength is less likely to occur, which is preferable. Here, "exhibiting a storage elastic modulus of 0.10 to 5.0 MPa at 23 to 80° C." means that the storage elastic modulus has a value within the above range at any temperature within this range. Since the storage elastic modulus usually decreases gradually as the temperature rises, if the storage elastic moduli at 23° C. and 80° C. are both within the above range, the adhesive layer has a storage elastic modulus within the above range at temperatures within this range. can be viewed as showing The storage elastic modulus of the adhesive layer can be measured by a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device "DYNAMIC ANALYZER RDA II" manufactured by REOMETRIC.

[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 conductive layers include, for example, aluminum, copper, silver, iron, tin, zinc, platinum, nickel, molybdenum, chromium, tungsten, lead, titanium, palladium, indium, and alloys containing two or more of these metals. It may be a layer containing at least one metal element selected from. Among these, the conductive layer may be a layer containing at least one metal element preferably selected from aluminum, copper, silver and gold from the viewpoint of conductivity, and from the viewpoint of conductivity and cost, More preferably, it may be a layer containing an aluminum element. In addition, in the case of a layer containing copper, a blackening treatment may be performed from the viewpoint of preventing reflection of light. The blackening treatment is to oxidize the surface of the conductive layer to precipitate Cu ₂ O or CuO. The conductive layer may also be a layer containing, for example, metallic silver, ITO (tin-doped indium oxide), graphene, zinc oxide, or AZO (aluminum-doped zinc oxide).

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). Examples of the method of forming the conductive layer on the substrate include sputtering. The substrate may be a transparent substrate constituting a liquid crystal cell included in the touch input device, or may be a glass substrate. The transparent substrate may be made of, for example, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyethylene naphthalate, polyethersulfone, cyclic olefin copolymer, triacetyl cellulose, polyvinyl alcohol, polyimide, polystyrene, biaxially oriented polystyrene, and the like. The glass substrate may be made of, for example, soda-lime glass, low-alkali glass, alkali-free glass, or the like. The conductive layer may be formed on the entire surface of the substrate or may be formed on a portion thereof.

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

Examples of the metal wiring layer include a layer obtained by adding a metal mesh, which is a metal wiring layer of fine wires, metal nanoparticles, and metal nanowires to a binder. Note that the metal mesh indicates a two-dimensional network structure formed of metal wiring. The shape of the openings of the metal mesh (openings or meshes between wires) is not particularly limited, and may be, for example, polygonal (triangular, quadrangular, pentagonal, hexagonal, etc.), circular, elliptical, or irregular. and each opening may be the same or different. In a preferred embodiment, the shapes of the openings of the metal mesh are the same shape and square or rectangular.

When the conductive layer is a metal wiring layer (especially metal mesh), the metal wiring may be arranged at predetermined intervals in the vertical and horizontal directions of the plane on the substrate X, for example. At this time, the opening may be filled with a resin (adhesive, etc.), or the metal wiring layer may be embedded in the resin (adhesive, etc.). When resin or the like is used, the conductive layer (conductive layer 4) is composed of both metal wiring and resin (adhesive).

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

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, It is usually 0.01 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more. The thickness of the conductive layer may be a combination of these upper and lower limits, preferably 0.01 to 3 μm, more preferably 0.05 to 1 μm. When the conductive layer is a metal wiring layer and the metal wiring layer is composed of both resin (adhesive, etc.) and metal wiring, the thickness of the conductive layer includes the resin.

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

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

The optical laminate of the present invention is obtained by laminating (or lamination).

An optical laminate having a conductive layer (e.g., a conductive transparent metal oxide layer, a metal wiring layer, etc.) is useful because it can be used for a touch input type liquid crystal display device having a touch panel function. The dichroic dye (iodine) contained in is transferred to the conductive layer, and the conductive layer is easily corroded. In particular, when a metal wiring layer such as a metal mesh is used, the conductive layer is more easily corroded due to the narrow line width. However, since the optical laminate of the present invention includes the first cured material layer, it is possible to effectively suppress the migration of the dichroic dye to the conductive layer and effectively prevent corrosion of the conductive layer.

[Polarizing film]
The polarizing film constituting the optical laminate of the present invention is a film having the function of extracting linearly polarized light from incident natural light. In the present invention, the polyvinyl alcohol resin film contains a dichroic dye, preferably iodine. It is a film that has been adsorbed and oriented. 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, and copolymers of vinyl acetate with other monomers copolymerizable therewith (e.g., ethylene-vinyl acetate copolymer). coalescence, etc.). Other monomers copolymerizable with vinyl acetate include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol %, preferably 98 mol % or more. The polyvinyl alcohol-based resin may be modified, and for example, aldehyde-modified polyvinyl formal, polyvinyl acetal, polyvinyl butyral, and the like can be used. The degree of polymerization of the polyvinyl alcohol resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

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

A polarizing film is usually produced by a process of uniaxially stretching such a polyvinyl alcohol resin film, a process of dyeing the polyvinyl alcohol resin film with a dichroic dye to adsorb a dichroic dye, and a process in which the dichroic dye is absorbed. It is produced through a step of treating the adsorbed polyvinyl alcohol-based resin film with an aqueous boric acid solution, and a step of washing with water after the treatment with the aqueous boric acid solution.

The uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before dyeing with the dichroic dye, may be performed simultaneously with dyeing, or may be performed after dyeing. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. It is also possible to carry out uniaxial stretching in these multiple stages. In the uniaxial stretching, the film may be uniaxially stretched between rolls having different circumferential speeds, or may be uniaxially stretched using hot rolls. The uniaxial stretching may be dry stretching in which the film is stretched in the atmosphere, or may be wet stretching in which the polyvinyl alcohol-based resin film is stretched in a swollen state using a solvent. From the viewpoint of suppressing deformation of the polarizing film, the draw ratio is preferably 8 times or less, more preferably 7.5 times or less, and still more preferably 7 times or less. Moreover, the draw ratio is preferably 4.5 times or more from the viewpoint of expressing the function as a polarizing film.

In the present invention, a method of dyeing by immersing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in the aqueous solution is usually 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually 0.5 to 20 parts by weight per 100 parts by weight of water. . The temperature of the aqueous solution used for dyeing is usually 20 to 40° C., and the immersion time (dyeing time) in this aqueous solution is usually 20 to 1800 seconds.

The boric acid treatment after dyeing with iodine can be performed 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, 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, more preferably 60 to 80°C.

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

Thus, the polyvinyl alcohol-based resin film is uniaxially stretched, dyed with a dichroic dye, preferably iodine, and treated with boric acid to obtain a polarizing film. The thickness of the polarizing film can be, for example, 5 to 40 μm.

[Second hardened layer]
The optical laminate of the present invention may comprise a second cured layer made of a cured curable composition on the opposite side of the polarizing film to the first cured layer. The curable composition that constitutes the second cured layer can be appropriately selected according to the adhesiveness to the polarizing film or the second protective film, and is included in the range of the curable composition that constitutes the first cured layer described above. It may be a composition that can be used, or it may be a photocurable adhesive or the like known in the art. When using a composition included in the range of the curable composition constituting the first cured layer, a curable composition having the same composition as the curable composition of the first cured layer constituting the optical laminate is used. It may be used for the second cured layer, and a curable composition having a different composition may be used for the second cured layer.

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

The second cured layer is formed by applying a curable composition constituting the second cured layer to the surface of the optical layered body opposite to the side on which the first cured layer is laminated by a known method, and curing the composition. It can be formed by letting The coating method of the curable composition constituting the second cured material layer includes, for example, the same coating method as the coating method of the curable composition (1).

When a photocurable composition or a known photocurable adhesive is used as the curable composition constituting the second cured layer, the curable composition or curable adhesive is irradiated with an active energy ray. to cure. The light source of the active energy ray is not particularly limited, but an active energy ray having a light emission distribution at a wavelength of 400 nm or less is preferable. Specifically, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, chemical lamp, black light lamp. , microwave excited mercury lamps, metal halide lamps and the like are preferred.

The intensity of light irradiation to the curable composition constituting the second cured layer can be appropriately selected depending on the composition of the curable composition and is not particularly limited, but 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 to the curable composition constituting the second cured material layer may be appropriately selected depending on the curable composition to be cured, and the integrated light amount represented as the product of the irradiation intensity and the irradiation time is preferably It is set to be 10 to 5000 mJ/cm ² .

In addition, when the curable composition is cured by irradiation with active energy rays, for example, the degree of polarization, transmittance and hue of the polarizing film, and the transparency of various films constituting the protective film and the optical layer. Curing is preferably carried out under conditions where various functions do not deteriorate. Although the thickness of the second cured product layer is not particularly limited, it is usually 0.1 to 10 μm.

〔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 one embodiment, the optical laminate of the present invention is laminated on the other side of the polarizing film (the side opposite to the first cured layer 2) via the second cured layer. It has a second protective film (6 shown in FIGS. 1 and 2). From the viewpoint of preventing shrinkage and expansion of the polarizing film and preventing deterioration of the polarizing film due to temperature, humidity, ultraviolet rays, etc., in one embodiment, the optical laminate of the present invention has the first protective film. On the other hand, from the viewpoint of thinning the optical layered body, in one embodiment, the optical layered body of the present invention does not contain 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 the protective film, from the viewpoint of achieving well-balanced prevention of deterioration of the polarizing film and thinning of the optical laminate, the optical layer of the present invention It is preferred that the laminate does not contain the first protective film.

As a material for forming the protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture shielding property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; acrylic polymers such as polymethyl methacrylate; styrenes such as polystyrene and acrylonitrile-styrene copolymer (AS resin). -based polymer: Polycarbonate-based polymer can be mentioned. In addition, polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure; polyolefin-based polymers such as ethylene-propylene copolymers; vinyl chloride-based polymers, amide-based polymers such as nylon and aromatic polyamides; imide-based polymers, sulfone-based polymer, polyethersulfone-based polymer, polyetheretherketone-based polymer, polyphenylene sulfide-based polymer, vinyl alcohol-based polymer, vinylidene chloride-based polymer, vinyl butyral-based polymer, arylate-based polymer, polyoxymethylene-based polymer, epoxy-based polymer, or Blends of the above polymers are also examples of polymers that form protective films. The protective film can also be formed as a cured product layer of a thermosetting or UV-curable resin such as acrylic, urethane, acrylic urethane, epoxy, or silicone. Among them, those having a hydroxyl group having reactivity with an isocyanate cross-linking agent are preferable, and cellulose-based polymers are particularly preferable.
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 may be made of different materials.

The moisture permeability of the second protective film is preferably 1200 g / (m ² · 24 hours) or less, more preferably 800 g / (m ² · 24 hours) or less at a temperature of 23 ° C. and a relative humidity of 55%, It is more preferably 600 g/(m ² ·24 hours) or less, particularly preferably 400 g/(m ² ·24 hours) or less, and most preferably 200 g/(m ² ·24 hours) or less. If the moisture permeability of the second protective film is the above value or less, it prevents the infiltration of moisture from the outside under high temperature and high humidity, and prevents the accelerated movement of the dichroic dye (iodine) contained in the polarizing film. Therefore, corrosion of the conductive layer and deterioration of optical properties can be prevented more effectively. On the other hand, since the optical laminate of the present invention has the first cured product layer, even if the second protective film does not satisfy the moisture permeability, the dichroic dye (iodine) contained in the polarizing film is suppressed from moving, It is possible to prevent deterioration of the conductive layer and deterioration of optical properties.

The thickness of the protective film is not particularly limited. 10 to 100 μm. Moreover, the protective film may be composed of a protective film or the like to which an optical compensation function is added.

In the optical laminate of the present invention, the first cured product layer can effectively suppress migration of the dichroic dye from the polarizing film to the adhesive layer and migration of the ionic compound from the adhesive layer to the polarizing film. Therefore, the selection range for the material of the first protective film that constitutes the optical layered body is widened. That is, there is no need to use a protective film impermeable to ionic compounds, and it is possible to construct an optical laminate using a generally inexpensive protective film that facilitates permeation of ionic compounds. The optical layered body of the present invention is also advantageous from an industrial point of view, for example, the production cost can thus be reduced.

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

Further, the optical layered body of the present invention may have a protective film between the polarizing film and the first cured layer via an adhesive layer. Examples of the protective film include protective films similar to the above-exemplified first protective film or second protective film. The thickness of the protective film is also usually 5 to 500 μm, like the first protective film or the second protective film.

In the optical laminate of the present invention, the first cured layer can effectively prevent migration of the dichroic dye even without a protective film between the polarizing film and the first cured layer. For this reason, the optical laminate of the present invention has an aspect in which the first cured product layer is directly laminated on the polarizing film, an aspect in which the first cured product layer is laminated on the polarizing film via a primer layer, or an aspect in which the first cured product layer is laminated on the polarizing film via the primer layer. A mode in which a pressure-sensitive adhesive layer is laminated on one cured product layer via a primer layer is preferred.

The optical layered body of the present invention may further have optical layers such as a retardation film, a viewing angle compensation film and a brightness enhancement film, if necessary. The optical layers in the optical laminate of the present invention can be formed using materials known in the art.

The optical layered body 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 bonded to the second curable composition layer to produce a laminate. In the case of the optical laminate that does not contain the first protective film, the curable composition (1) is applied onto the peelable film to form the first curable composition layer, and the polarizing film side of the laminate is applied to the coated surface. are pasted together. Next, the second cured composition layer and the first cured composition layer are cured by irradiation with active energy rays such as ultraviolet rays and electron beams to form the second cured material layer and the first cured material layer. After that, the peelable film is peeled off to form an adhesive layer on the first cured layer. Then, for example, a pressure-sensitive adhesive layer may be attached to the conductive layer laminated on the substrate. On the other hand, in the case of an optical laminate including a first protective film, the curable composition (1) is applied onto the protective film to form a first curable composition layer, and the polarizing film side of the laminate is applied to the coated surface. After laminating, the first cured composition layer is cured by irradiating active energy rays such as ultraviolet rays and electron beams to form the first cured material layer, and then the adhesive layer is formed on the first protective film. do. Then, for example, a pressure-sensitive adhesive layer may be attached to the conductive layer laminated on the substrate.

From the standpoint of reducing unevenness in thickness when the curable composition is applied and achieving both thinning of the optical layered body, it is possible to form the layered body using a separate film (release film) as described above. can. For example, a laminate consisting of a polarizing film and a first cured product layer is obtained by laminating a separate film (release film) on one side of the polarizing film with the first cured product layer interposed therebetween, and applying an active energy ray or the like to perform the first curing. It can be formed by peeling off a separate film (release film) after curing the material layer.

The present invention comprises a cured product of a curable composition containing a polymerizable compound on one side of an optical laminate having the above-described structure, that is, a polarizing film containing a dichroic dye in a polyvinyl alcohol resin. An optical laminate (an optical laminate shown in FIGS. 1 and 2 in one embodiment) in which a first cured product layer, an adhesive layer, and a conductive layer are laminated in this order,
The polymerizable compound contains an oxetane compound having two or more oxetanyl groups, and the content of the oxetane compound is 40 parts by mass or more with respect to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition. The optical layered body is included. When the oxetane compound having two or more oxetanyl groups is included in a predetermined amount or more, a dense first cured product layer with a high crosslink density can be formed, so the first cured product of the dichroic dye (iodine) contained in the polarizing film The migration to the layer can be effectively suppressed, and the corrosion of the conductive layer and the deterioration of the optical performance due to the dichroic dye (iodine) can be effectively prevented. In such an optical laminate, the absorbance increase rate of the first cured product 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 content ( (including preferred ingredients and contents) are the same as those described above. The polarizing film, adhesive layer, and conductive layer contained in the optical layered body are also the same as those described above.

In the present invention, a first cured product layer composed of a cured product of a curable composition containing a polymerizable compound on one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, and an adhesive layer and a conductive layer are laminated in this order, and the optical laminate in which the water contact angle of the first cured layer is 90 ° or more is due to the excellent hydrophobicity of the first cured layer As a result, it effectively suppresses the movement of the dichroic dye (iodine) even in a high temperature and high humidity environment where the movement of the dichroic dye (iodine) is remarkable, and effectively prevents corrosion of the conductive layer and deterioration of optical performance. can do.

In the present invention, the water contact angle of the first cured product layer is, for example, 90° or more, preferably 95° or more, more preferably 100° or more. When the water contact angle is at least the above value, even under high temperature and high humidity, it effectively suppresses the movement of the dichroic dye to the first cured product layer, effectively preventing corrosion of the conductive layer and deterioration of optical performance. can be prevented.

In the present invention, a first cured product layer composed of a cured product of a curable composition containing a polymerizable compound on one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin, and an adhesive layer and a conductive layer laminated in this order, the optical laminate having a storage elastic modulus of 1500 MPa or more at 30° C. of the first cured layer has a relatively high crosslink density. Therefore, it has a high barrier property against dichroic dye (iodine), effectively suppresses the migration of dichroic dye (iodine) to the first cured product layer, and effectively prevents corrosion of the conductive layer and deterioration of optical performance. can be prevented.

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

In the present invention, a first cured product layer composed of a cured product of a curable composition (1) containing a polymerizable compound on one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin; , An optical layered body in which an adhesive layer and a conductive layer are laminated in this order, and the optical layered body in which the glass transition temperature of the first cured material layer is 90 ° C. or higher has a relatively high crosslink density. As a result, it has a high barrier property against dichroic dye (iodine), effectively suppresses the migration of dichroic dye (iodine) to the first cured product layer, and effectively prevents corrosion of the conductive layer and deterioration of optical performance. can be prevented.

The glass transition temperature of the first cured product layer is, for example, 90 to 180°C, preferably 100 to 180°C, more preferably 120 to 180°C, still more preferably 150 to 180°C. When the elastic modulus is at least the above lower limit, the migration of the dichroic dye (iodine) to the first cured product layer is more effectively suppressed, and corrosion of the conductive layer and deterioration of optical performance are more effectively prevented. be able to.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples. "%" and "parts" in Examples and Comparative Examples represent "% by mass" and "parts by mass", respectively, unless otherwise specified.

[Example 1]
1. Preparation of Curable Composition (I) Constituting First Cured Layer According to the composition shown in Table 1 below, each component was mixed to prepare curable compositions (I) of Production Examples 1 to 31.

2. Evaluation of absorbance increase rate of first cured layer (iodine ion absorption evaluation)
The curable composition (I) of Production Example 1 was applied to one side of a cycloolefin film having a thickness of 50 μm [trade name “ZEONOR”, manufactured by Nippon Zeon Co., Ltd.] using a bar coater. It was coated so as to have a thickness of about 30 μm. A 50 μm-thick cycloolefin film [trade name “ZEONOR”, manufactured by Nippon Zeon Co., Ltd.] was laminated on the coated surface to prepare a laminate. From the cycloolefin film side of the laminate, an ultraviolet irradiation device with a belt conveyor [a lamp used is "D Bulb" manufactured by Fusion UV Systems] so that the integrated light amount at 280 nm to 320 nm is 1000 mJ / cm ² . was irradiated with ultraviolet rays to cure the curable composition (I) to obtain a laminate in which cycloolefin films were laminated on both sides of the first cured material layer. The cycloolefin films on both sides of the obtained laminate were peeled off to isolate the cured product (first cured product layer) of the curable composition (I), which was used as an evaluation sample.
The absorbance at 360 nm of the evaluation sample was measured using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, "UV2450"). Let this absorbance be the absorbance before immersion.
Next, the sample for evaluation was immersed in a 50% aqueous solution of potassium iodide for 100 hours in the air at a temperature of 23° C. and a relative humidity of 60%. After taking out the sample for evaluation and wiping the surface with pure water, the absorbance at 360 nm was measured using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, "UV2450"). Let this absorbance be the absorbance after immersion.
Using the obtained absorbance, the rate of increase in absorbance (%) represented by the following formula was calculated. Table 1 shows the results. Similarly, the rate of increase in absorbance of each cured layer formed from the curable composition (I) of Production Examples 2 to 31 was determined. Table 1 shows the results.
Absorbance increase rate (%) = (absorbance after immersion (360 nm) - absorbance before immersion (360 nm)) / absorbance before immersion (360 nm) x 100 (1)

Each component in Table 1 is shown below.
<Alicyclic epoxy compound (B2)>
B2-1: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (“Celoxide 2021P” (trade name), manufactured by Daicel Chemical Industries, Ltd.) B2-2: 2,2-bis(hydroxymethyl)- 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 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., compound having one oxetanyl group)
a1-2: 3-ethyl-3-hydroxymethyloxetane (“OXT-101” (trade name), manufactured by Toagosei Co., Ltd., compound having one oxetanyl group)
<Acrylic compound>
P1-1: Tricyclodecanedimethanol diacrylate (“A-DCP” (trade name), manufactured by Shin-Nakamura Chemical Co., Ltd.)
P1-2: Diacrylate of acetal compound of hydroxypivalaldehyde and trimethylolpropane (“A-DOG (trade name)”, manufactured by Shin-Nakamura Chemical Co., Ltd.)
<Polymerization initiator>
G1-1: Photocationic polymerization initiator: propylene carbonate 50 solution of triarylsulfonium hexafluorophosphate (“CPI-100P” (trade name), manufactured by San-Apro Co., Ltd.)
G1-2: photoradical polymerization initiator: 2-hydroxy-2-methyl-1-phenyl-propan-1-one (“Darocure 1173” (trade name), manufactured by BASF Japan Ltd.)
<Leveling agent>
S1-1: Silicone-based leveling agent ("SH710" (trade name), manufactured by Dow Corning Toray Co., Ltd.)

3. Preparation of polarizing film Polyvinyl alcohol film with a thickness of 20 μm (manufactured by Kuraray Co., Ltd., “Kuraray Poval KL318” (trade name): carboxyl group-modified polyvinyl alcohol, average degree of polymerization: about 2,400, degree of saponification: 99.9 mol% above) was uniaxially stretched about 5 times by dry stretching, and further immersed in pure water at 60 ° C. for 1 minute while maintaining the tension, and then the mass ratio of iodine / potassium iodide / water was 0.05 / It was immersed in a 5/100 aqueous solution at 28° C. for 60 seconds. After that, it was 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. Further, after washing with pure water at 26° C. for 20 seconds and drying at 65° C., a polarizing film (1) having a thickness of 7 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol film was obtained.

4. Preparation of water-based adhesive Pure 100 parts by mass, polyvinyl alcohol film (manufactured by Kuraray Co., Ltd., “Kuraray Poval KL318” (trade name): carboxyl group-modified polyvinyl alcohol) 3.0 parts by mass, and water-soluble polyamide epoxy resin Ka Chemtex Co., Ltd., "Sumireze Resin 650" (trade name), working solution with a solid concentration of 30%) was mixed to prepare a water-based adhesive (1). In addition, the mass part of "Sumireze resin 650" has shown the mass of solid content.

5. Preparation of laminate (1) A water-based adhesive (1) was applied to one surface of the polarizing film (1), and a triacetyl cellulose film (manufactured by Toppan Tomoegawa Optical Film Co., Ltd., manufactured by Toppan Tomoegawa Optical Film Co., Ltd., " 25KCHC-TC (trade name), thickness 32 μm) was subjected to saponification treatment, and then the surface not subjected to hard coating treatment was bonded to a polarizing film via water-based adhesive (1). This was dried at 60° C. for 6 minutes to produce a laminate (1) having a protective film on one side.

6. Preparation of laminate (2) On one side of a 50 μm thick cycloolefin film [trade name “ZEONOR”, manufactured by Nippon Zeon Co., Ltd.], the curable composition (I) was applied using a bar coater. It was coated so that the film thickness was about 3 μm. The polarizing film side of the laminate (1) was attached to the coated surface to prepare a laminate. From the cycloolefin-based film side of the laminate, an ultraviolet irradiation device with a belt conveyor [a lamp using "D bulb" manufactured by Fusion UV Systems] was used so that the integrated light amount at 280 nm to 320 nm was 200 mJ / cm ² . was irradiated with ultraviolet rays to cure the curable composition (I), and then the cycloolefin film was peeled off. A laminate (2) composed of protective film/aqueous adhesive/polarizer film/cured product (first cured product layer) of curable composition (I) was produced.

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 applied to a polyethylene terephthalate film having a thickness of 38 μm [manufactured by Lintec Corporation. , “SP-PLR382050” (trade name), referred to as a release film], is coated with a die coater so that the thickness after drying is 20 μm, and dried to form a sheet with a release film. An adhesive was produced. Next, the surface (adhesive surface) of the sheet-like adhesive obtained on the side opposite to the release film was laminated to the first cured product layer side of the laminate (2) using a laminator. After curing for 7 days at a humidity of 65%, a laminate (3) provided with an adhesive layer was obtained. This laminate has a structure in which a release film is laminated on an adhesive layer.

The acrylic pressure-sensitive adhesive contains the following.
<Base polymer>
Copolymer of butyl acrylate, methyl acrylate, acrylic acid and hydroxyethyl acrylate <isocyanate cross-linking agent>
Ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content 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);

8. Evaluation of ITO Corrosion Resistance An ITO film was formed on one surface of alkali-free glass by a sputtering method to prepare a glass having an ITO film. The glass having this ITO thin film was cut into a size of 25 mm x 25 mm, and the central portion of the ITO thin film was measured using a low resistivity meter ("Loresta AX MCP-T370", manufactured by Mitsubishi Chemical Analytic Tech). initial resistance value”. Next, the laminate (3) was cut into a size of 15 mm x 15 mm, and the pressure-sensitive adhesive layer of the laminate (3) and the ITO thin film were bonded together so that they were in contact with ^each other. 490.3 kPa) for 1 hour, and allowed to stand for 24 hours in an environment with a temperature of 23° C. and a relative humidity of 55%. This was used as a sample for evaluation. After that, this evaluation sample was placed in an environment of 80° C. and a relative humidity of 90% for 72 hours, then taken out, and the laminate (3) was peeled off. Then, the ITO thin film was washed with ethanol and measured using the same apparatus as described above to obtain the "resistivity after endurance". From the "initial resistance value" and "resistance value after endurance" measured as described above, the ITO resistance value increase rate was calculated by the following formula, and the ITO corrosiveness was evaluated according to the following evaluation criteria. Table 2 shows the results. The numbers in Table 2 indicate the rate of increase values in the following formula.
Resistance value increase rate (%) = (resistance value after endurance - initial resistance value) / initial resistance value x 100

◎: Resistance value increase rate is 20% or less ○: Resistance value increase rate is over 20% and less than 30% ×: Resistance value increase rate is 30% or more

9. Durability Evaluation of Laminate The laminate (3) was cut into a size of 30 mm × 30 mm, and the release film was peeled off. XG"]. This sample was subjected to an autoclave treatment at a temperature of 50° C. and a pressure of 5 kg/cm ² (490.3 kPa) for 1 hour, and then allowed to stand for 24 hours under an environment of a temperature of 23° C. and a relative humidity of 55%. Next, the optional accessory "film holder with polarizing film" is set in an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, "UV2450"), and the transmission axis direction and absorption of the laminate in the wavelength range of 380 to 700 nm are measured. The transmission spectrum in the axial direction was measured, and the degree of polarization Py (unit: %) was determined based on them. This degree of polarization was defined as the initial Py. Further, the degree of polarization was measured after standing for 24 hours in an environment of 80° C. and relative humidity of 90%, and this degree of polarization was defined as Py after the test. Based on these, the polarization degree change ΔPy was calculated by the following formula. Table 1 shows the results.
ΔPy = Py after test - initial Py

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

As shown in Table 2, in Examples 1 to 22, the optical laminate in which the first cured product layer had an absorbance increase rate of 30% or less did not corrode ITO even when placed under high temperature and high humidity for a long time. It shows that it can be effectively suppressed. In particular, Examples 4 to 20 and Example 22 show that the optical layered body in which the first cured product layer has an absorbance increase rate of 20% or less can more effectively suppress the corrosion of ITO. Moreover, Examples 1 to 22 show that optical laminates having an absorbance increase rate of 30% or less are excellent in durability and can maintain optical performance even under high temperature and high humidity conditions.

As shown in Table 2, in Examples 1 to 22, the first cured product layer contained 40 parts by mass or more of an oxetane compound having two or more oxetanyl groups with respect to 100 parts by mass of the total amount of all polymerizable compounds. It shows that the optical laminate, which is a cured product layer, can more effectively suppress the corrosion of ITO.

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

Claims (6)

On one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin,
A first cured product layer composed of a cured product of a curable composition containing a polymerizable compound, an adhesive layer,
An optical laminate in which a conductive layer and a conductive layer are laminated in this order,
The optical laminate, wherein the first cured product layer has an absorbance increase rate represented by the following formula (1) of 30% or less.
Absorbance increase rate (%) = (Abs after immersion (360 nm) - Abs before immersion (360 nm)) / Abs before immersion (360 nm) x 100 (1)
[In the formula, Abs after immersion (360 nm) is the absorbance at 360 nm after immersing the cured product in a 50% aqueous potassium iodide solution for 100 hours in an atmosphere at a temperature of 23 ° C. and a relative humidity of 60%. Abs (360 nm) indicates the absorbance at 360 nm before the cured product is immersed in a 50% potassium iodide aqueous solution] On one side of a polarizing film containing a dichroic dye in a polyvinyl alcohol-based resin,
A first cured product layer composed of a cured product of a curable composition containing a polymerizable compound, an adhesive layer,
An optical laminate in which a conductive layer and a conductive layer are laminated in this order,
The polymerizable compound contains an oxetane compound having two or more oxetanyl groups, and the content of the oxetane compound is 40 parts by mass or more with respect to 100 parts by mass of the total amount of all polymerizable compounds contained in the curable composition. is an optical laminate. 3. The optical laminate according to claim 1, wherein the first cured layer has a thickness of 0.1 to 15 μm. 4. The optical laminate according to any one of claims 1 to 3, wherein the cured product constituting the first cured product layer is a photocured product of a curable composition containing the polymerizable compound. 5. The optical laminate according to any one of claims 1 to 4, wherein a second cured layer and a protective film are laminated on the opposite side of the polarizing film to the first cured layer. 6. The optical laminate according to claim 5, wherein the protective film has a moisture permeability of 1200 g/(m ² ·24 hours) or less at a temperature of 23° C. and a relative humidity of 55%.

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