KR20200012883A - Polarizing plate with pressure-sensitive adhesive layer - Google Patents

Abstract

Provided is a polarizing plate with a pressure-sensitive adhesive layer capable of providing a laminated optical member having good warpage resistance and heat resistance.
A polarizing plate having a maximum curling force at 80 ° C. of 500 mN or more, and a pressure-sensitive adhesive layer laminated on the polarizing plate, wherein the pressure-sensitive adhesive layer has a gel fraction (G80) [%] and 23 ° C. after heating at 80 ° C. for 24 hours. The polarizing plate with an adhesive layer whose absolute value of the difference of the gel fraction (G23) [%] of more than 5 points is provided.

Description

Polarizing plate with pressure-sensitive adhesive layer

This invention relates to the polarizing plate with an adhesive layer containing a polarizing plate and the adhesive layer laminated | stacked on it.

A polarizing plate formed by laminating a protective film on one or both sides of a polarizer is an image display device such as a liquid crystal display device or an organic electroluminescent (organic EL) display device including mobile television, particularly in recent years, such as a mobile phone or a smartphone. And optical members widely used in various mobile devices such as tablet terminals.

The polarizing plate is often bonded to an image display element (liquid crystal cell, organic EL display element, etc.) via an adhesive layer, and is used (for example, refer to Japanese Patent Laid-Open No. 2010-229321 (Patent Document 1)). For this reason, a polarizing plate may be marketed in the form of the polarizing plate with an adhesive layer in which the adhesive layer was previously formed in one surface.

Patent Document 1: Japanese Unexamined Patent Publication No. 2010-229321

The laminated optical member formed by laminating and bonding a polarizing plate with an adhesive layer to optical members, such as an image display element, is influenced by the influence of a heat | fever etc. in the manufacturing process incorporated into an image display apparatus, or when incorporated and used in an image display apparatus. It may generate curvature by this. In recent years, with the thinning of an image display element and a polarizing plate, the problem of the bending of a laminated optical member becomes increasingly remarkable.

The bending of the laminated optical member lowers the workability of the manufacturing process, or when a laminated optical member is stored in the frame and shipped, a part of the laminated optical member is pushed to the frame to apply stress to the frame, thereby causing damage to the laminated optical member. Problems such as this may occur.

In addition, the laminated optical member has been required to have heat resistance that has good performance even in the manufacturing process incorporated into the image display apparatus or when incorporated into the image display apparatus and used under the influence of heat.

This invention provides the polarizing plate with an adhesive layer which can provide the laminated optical member which is excellent in the said bending (henceforth "bending resistance"), and heat resistance.

This invention provides the polarizing plate with an adhesive layer and laminated optical member shown below.

[1] a polarizing plate having a maximum curl force of 80 mN or more at 80 ° C.,

Pressure-sensitive adhesive layer laminated on the polarizing plate

Including,

The said adhesive layer is a polarizing plate with an adhesive layer in which the absolute value of the difference of the gel fraction (G80) [%] and the gel fraction (G23) [%] in 23 degreeC after heating at 80 degreeC for 24 hours is larger than 5 points. .

[2] The polarizing plate with a pressure sensitive adhesive layer according to [1], wherein the pressure sensitive adhesive layer has a gel fraction (G80) of 60% or more after heating at 80 ° C. for 24 hours.

[3] The polarizing plate with pressure sensitive adhesive layer according to [1] or [2], wherein the pressure sensitive adhesive layer has a gel fraction (G80) of 95% or less after heating at 80 ° C. for 24 hours.

[4] The polarizing plate with a pressure sensitive adhesive layer according to any one of [1] to [3], wherein the polarizing plate includes a polarizer having a thickness of 10 µm or more.

[5] The polarizing plate with pressure sensitive adhesive layer according to any one of [1] to [4], wherein the pressure sensitive adhesive layer is formed of a pressure sensitive adhesive composition containing (meth) acrylic resin.

[6] The polarizing plate with a pressure sensitive adhesive layer according to [5], in which the (meth) acrylic resin includes a structural unit derived from a (meth) acrylic monomer having a carboxyl group and a structural unit derived from an alkoxyalkyl (meth) acrylamide monomer. .

[7] The polarizing plate with a pressure sensitive adhesive layer according to [5] or [6], wherein the pressure sensitive adhesive composition has a content of a crosslinking agent of from 0 parts by mass to 2 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin.

[8] A laminated optical member, which is a laminate of the polarizing plate with the pressure-sensitive adhesive layer according to any one of [1] to [7] and an optical member other than the polarizing plate with the pressure-sensitive adhesive layer.

The polarizing plate with an adhesive layer which can provide the laminated optical member which is excellent in curvature resistance and heat resistance can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows an example of the polarizing plate with an adhesive layer and laminated optical member which concerns on this invention.
2 is a schematic cross-sectional view showing another example of the polarizing plate with pressure-sensitive adhesive layer and the laminated optical member according to the present invention.
3 is a schematic cross-sectional view showing still another example of the polarizing plate with pressure-sensitive adhesive layer and the laminated optical member according to the present invention.
4 is a schematic cross-sectional view showing still another example of the polarizing plate with pressure-sensitive adhesive layer and the laminated optical member according to the present invention.

<Polarizer with Adhesive Layer>

[1] Configuration of polarizing plate with pressure sensitive adhesive layer

The polarizing plate with an adhesive layer contains a polarizing plate and an adhesive layer laminated | stacked on it. 1-4, the example of the laminated constitution of the polarizing plate with an adhesive layer is shown.

The polarizing plate 25 with an adhesive layer shown in FIG. 1 includes the polarizing plate 10 and the 1st adhesive layer 20 laminated | stacked on it. The polarizing plate 10 has the polarizer 1 and the 1st protective film 3 adhering to the single side | surface. The 1st protective film 3 is adhere | attached on the surface on the opposite side to the 1st adhesive layer 20 in the polarizer 1. As in the example shown in FIG. 1, the first protective film 3 may have a surface treatment layer 2 formed on its outer surface (the surface opposite to the polarizer 1). The first adhesive layer 20 can be used, for example, for bonding to the optical member 30. The optical member 30 is mentioned later.

The polarizing plate 25 with an adhesive layer shown in FIG. 2 is the same as that of FIG. 1 except that the polarizing plate 10 further includes the 2nd protective film 4 adhere | attached on the other surface of the polarizer 1. The first adhesive layer 20 is laminated on the outer surface of the second protective film 4.

The polarizing plate 25 with the pressure-sensitive adhesive layer shown in FIG. 3 further includes a phase difference film 7 in which the polarizing plate 10 is bonded to the other side of the polarizer 1 via the second pressure-sensitive adhesive layer 8. Same as 1

The polarizing plate 25 with the pressure-sensitive adhesive layer shown in FIG. 4 further includes a phase difference film 7 in which the polarizing plate 10 is adhered to the outer surface of the second protective film 4 through the second pressure-sensitive adhesive layer 8. Other than that is the same as FIG. In the example shown in FIG. 3 and FIG. 4, the 1st adhesive layer 20 is adhere | attached on the retardation film 7. As shown in FIG.

The polarizing plate 25 with an adhesive layer may have a separate film laminated | stacked on the outer surface of the 1st adhesive layer 20. FIG.

[2] polarizing plate

The polarizing plate 10 which comprises the polarizing plate 25 with an adhesive layer contains at least the polarizer 1, and usually contains the polarizer 1 and the thermoplastic resin film as a protective film etc. laminated | stacked and bonded to at least one side thereof. do.

[2-1] polarizer

The polarizer 1 is a film having a function of selectively transmitting linearly polarized light in any one direction from natural light. For example, an iodine polarizer in which iodine as a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin film, a dye polarizer in which dichroic dye as a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin film, and a lyotropic liquid crystal The coating type polarizer etc. which coated the dichroic dye of the state, and orientated and fixed are mentioned. These polarizers are called absorption type polarizers because they selectively transmit linearly polarized light in one direction from natural light and absorb linearly polarized light in the other direction.

The polarizer 1 is not limited to an absorption type polarizer, but is a reflective polarizer that selectively transmits linear polarization in one direction from natural light and reflects linear polarization in another direction, or a scattering type for scattering linear polarization in another direction. Although it may be a polarizer, an absorption type polarizer is preferable at the point which is excellent in visibility. Especially, the polyvinyl alcohol-type polarizer comprised from polyvinyl alcohol-type resin is more preferable, The polyvinyl alcohol-type polarizer which adsorbed and oriented dichroic dyes, such as iodine and a dichroic dye, to a polyvinyl alcohol-type resin film further A polyvinyl alcohol polarizer in which iodine is adsorbed and aligned on a polyvinyl alcohol resin film is particularly preferable.

As polyvinyl alcohol-type resin which comprises a polyvinyl alcohol-type polarizer, what saponified polyvinyl acetate type resin can be used. As polyvinyl acetate type resin, the copolymer etc. with the other monomer copolymerizable with vinyl acetate besides the polyvinyl acetate which is a homopolymer of vinyl acetate are mentioned. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth) acrylamides having an ammonium group.

The saponification degree of polyvinyl alcohol-type resin is 85 mol% or more and 100 mol% or less normally, and 98 mol% or more is preferable. The polyvinyl alcohol-based resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1000 or more and 10,000 or less, preferably 1500 or more and 5000 or less. The average polymerization degree of polyvinyl alcohol-type resin can be calculated | required based on JISK6726.

What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of the polarizer 1. The method of forming a polyvinyl alcohol-type resin into a film is not specifically limited, A well-known method is employ | adopted. The thickness of the polyvinyl alcohol-based master film is, for example, 150 µm or less, preferably 100 µm or less (for example, 50 µm or less), and 5 µm or more.

The polarizer 1 is a step of uniaxially stretching a polyvinyl alcohol-based resin film; Adsorbing a dichroic dye by dyeing a polyvinyl alcohol-based resin film with a dichroic dye; Treating (crosslinking) the polyvinyl alcohol-based resin film adsorbed with the dichroic dye with an aqueous boric acid solution; And it can manufacture by the method including the process of washing with water after the process by aqueous solution of boric acid.

Uniaxial stretching of a polyvinyl alcohol-type resin film can be performed before dyeing, simultaneously with dyeing, or after dyeing of a dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during boric acid treatment. In addition, you may uniaxially stretch in several of these steps.

At the time of uniaxial stretching, you may extend | stretch uniaxially between the rolls from which a circumferential speed differs, and may extend | stretch uniaxially using a heat roll. Moreover, uniaxial stretching may be dry stretching which extends | stretches in air | atmosphere, and wet extending | stretching may be performed in the state which swelled the polyvinyl alcohol-type resin film using solvents, such as water. The draw ratio is usually 3 times or more and 8 times or less.

As a method of dyeing a polyvinyl alcohol-type resin film with a dichroic dye, the method of immersing the said film in the aqueous solution containing a dichroic dye, etc. are mentioned, for example. As a dichroic dye, iodine and a dichroic organic dye are used. On the other hand, it is preferable that the polyvinyl alcohol-type resin film is immersed in water before a dyeing process.

As a dyeing processing method by iodine, the method of immersing a polyvinyl alcohol-type resin film in the aqueous solution containing iodine and potassium iodide, etc. are mentioned. Content of iodine in this aqueous solution may be 0.01 mass part or more and 1 mass part or less per 100 mass parts of water. Content of potassium iodide may be 0.5 mass part or more and 20 mass parts or less per 100 mass parts of water. In addition, the temperature of this aqueous solution may be 20 degreeC or more and 40 degrees C or less.

On the other hand, as a dyeing processing method by a dichroic organic dye, the method of immersing a polyvinyl alcohol-type resin film in the aqueous solution containing a dichroic organic dye, etc. are mentioned. The aqueous solution containing a dichroic organic dye may contain inorganic salts, such as sodium sulfate, as a dyeing adjuvant. Content of the dichroic organic dye in this aqueous solution may be 1 * 10 <^-4> mass part or more and 10 mass parts or less per 100 mass parts of water. The temperature of this aqueous solution may be 20 degreeC or more and 80 degrees C or less.

As a boric acid treatment method after dyeing with a dichroic dye, the method of immersing the dyed polyvinyl alcohol-type resin film in boric acid containing aqueous solution, etc. are mentioned. When using iodine as a dichroic dye, it is preferable that this boric acid containing aqueous solution contains potassium iodide. The amount of boric acid in boric-acid containing aqueous solution may be 2 mass parts or more and 15 mass parts or less per 100 mass parts of water. The amount of potassium iodide in this aqueous solution may be 0.1 mass part or more and 20 mass parts or less per 100 mass parts of water. The temperature of this aqueous solution may be 50 degreeC or more, for example, 50 degreeC or more and 85 degrees C or less.

The polyvinyl alcohol-based resin film after boric acid treatment is usually washed with water. A water washing process can be performed by immersing the polyvinyl alcohol-type resin film processed by boric acid in water, for example. The temperature of the water in a water washing process is 5 degreeC or more and 40 degrees C or less normally. After washing with water, a drying process is performed, and the polarizer 1 is obtained.

A drying process can be performed using a hot air dryer or a far infrared heater. The polarizing plate 10 can be obtained by bonding the thermoplastic resin film as a protective film etc. to one or both surfaces of this polarizer 1 using an adhesive agent.

Moreover, as another example of the manufacturing method of the polarizer 1, the method of Unexamined-Japanese-Patent No. 2000-338329 and Unexamined-Japanese-Patent No. 2012-159778 is mentioned, for example. In this method, after apply | coating the solution containing polyvinyl alcohol-type resin to the surface of a base film, and forming a resin layer, the laminated | multilayer film containing a base film and a resin layer is extended | stretched, and it dyes subsequently , Crosslinking treatment and the like are performed to form a polarizer layer (polarizer) from the resin layer. This polarizing laminated film containing a base film and a polarizer layer, after bonding a thermoplastic resin film as a protective film or the like to the polarizer layer surface, peeling and removing the base film, the polarizing plate 10 having a thermoplastic resin film on one side of the polarizer. Can be done. When a thermoplastic resin film is further bonded to the polarizer layer surface exposed by peeling of a base film, the polarizing plate 10 provided with a thermoplastic resin film on both surfaces of a polarizer is obtained.

The thickness of the polarizer 1 can be 40 micrometers or less, Preferably it is 30 micrometers or less. According to the method of Unexamined-Japanese-Patent No. 2000-338329 and Unexamined-Japanese-Patent No. 2012-159778, the polarizer 1 of a thin film can be manufactured more easily, and the thickness of the polarizer 1 is 20, for example. It becomes easier to set it as micrometer or less, Furthermore, 15 micrometers or less, Furthermore, 10 micrometers or less or 8 micrometers or less. The thickness of the polarizer 1 is usually 2 µm or more, preferably 5 µm or more, and more preferably 10 µm or more. Reducing the thickness of the polarizer 1 is advantageous for the thinning of the polarizing plate 10, and further, the polarizing plate 25 with an adhesive layer, the laminated optical member, and the image display device.

[2-2] thermoplastic resin film

The thermoplastic resin film bonded to one or both surfaces of the polarizer 1 is a transparent resin (preferably optically transparent), for example, a linear polyolefin resin (polypropylene resin or the like), cyclic ( Iii) polyolefin resins such as polyolefin resins (norbornene resins, etc.); Cellulose ester resins such as triacetyl cellulose and diacetyl cellulose; Polyester-based resins such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; Polycarbonate resins; (Meth) acrylic resins; Or a film made of a mixture thereof, a copolymer, or the like.

The thermoplastic resin film bonded to one or both surfaces of the polarizer 1 may be either a film that is not stretched or a film that is uniaxially or biaxially stretched. Biaxial stretching may be simultaneous biaxial stretching which draws simultaneously in two extending directions, and may be sequential biaxial stretching which extends in a 2nd direction different from this after extending | stretching in a 1st direction.

The thermoplastic resin film bonded to one or both surfaces of the polarizer 1 plays a role of protecting the polarizer 1 like the first and second protective films 3 and 4 shown in FIGS. 1 to 4. A protective film may be sufficient and the protective film which has optical functions, such as retardation film, may be sufficient.

A retardation film is an optical functional film used for the purpose of compensation of the phase difference by the liquid crystal cell which is an image display element. For example, it can be set as the retardation film to which arbitrary retardation value was provided by extending | stretching (uniaxial stretching or biaxial stretching etc.) of the said thermoplastic resin, or forming a liquid crystal layer etc. on the said thermoplastic resin film.

As chain | strand polyolefin resin, the copolymer containing 2 or more types of chain | strand olefins besides the homopolymer of chain | strand olefins, such as a polyethylene resin and a polypropylene resin, is mentioned.

Cyclic polyolefin resin is a general term for resin containing cyclic olefin which makes norbornene, tetracyclo dodecene (nickname: dimethanooctahydronaphthalene), or derivatives thereof as a polymer unit. Examples of the cyclic polyolefin resins include ring-opening (co) polymers of cyclic olefins and hydrogenated products thereof, addition polymers of cyclic olefins, copolymers of cyclic olefins with chain olefins such as ethylene and propylene or aromatic compounds having vinyl groups, and these And modified (co) polymers modified with an acid or a derivative thereof.

Especially, norbornene-type resin using norbornene-type monomers, such as a norbornene and a polycyclic norbornene-type monomer, is used suitably as cyclic olefin.

The cellulose ester-based resin may be a resin in which at least a part of the hydroxyl groups in the cellulose is acetate-esterified, a part of which is acetate-esterified, and a part of which is esterified with another acid. The cellulose ester resin is preferably an acetyl cellulose resin.

Examples of the acetyl cellulose resins include triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like.

Polyester-based resin is resin other than the said cellulose ester-type resin which has an ester bond, and what consists of polycondensates of polyhydric carboxylic acid or its derivative (s), and a polyhydric alcohol is common.

As polyester resin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate Etc. can be mentioned.

Among them, polyethylene terephthalate is preferably used in view of mechanical properties, solvent resistance, scratch resistance, cost, and the like. Polyethylene terephthalate means resin in which 80 mol% or more of a repeating unit is comprised from ethylene terephthalate, and may contain the structural unit derived from another copolymerization component.

As another copolymerization component, a dicarboxylic acid component and a diol component are mentioned.

As the dicarboxylic acid component, isophthalic acid, 4,4'-dicarboxydiphenyl, 4,4'-dicarboxybenzophenone, bis (4-carboxyphenyl) ethane, adipic acid, sebacic acid, 5-sodium sulfide Poisophthalic acid, 1, 4- dicarboxy cyclohexane, etc. are mentioned.

Examples of the diol component include propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, and ethylene oxide adducts of bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

A dicarboxylic acid component and a diol component can also be used in combination of 2 or more types, respectively as needed.

Moreover, it is also possible to use together hydroxycarboxylic acids, such as p-hydroxy benzoic acid, p-hydroxyethoxy benzoic acid, (beta) -hydroxyethoxy benzoic acid, with the said dicarboxylic acid component and diol component.

As another copolymerization component, a small amount of the dicarboxylic acid component and / or diol component which have an amide bond, a urethane bond, an ether bond, a carbonate bond, etc. may be used.

Polycarbonate resin is polyester formed from carbonic acid, glycol, or bisphenol. Especially, the aromatic polycarbonate which has a diphenyl alkane in a molecular chain is used preferably from a heat resistance, a weather resistance, and an acid resistance viewpoint.

Examples of the polycarbonate include 2,2-bis (4-hydroxyphenyl) propane (alias bisphenol A), 2,2-bis (4-hydroxyphenyl) butane and 1,1-bis (4-hydroxyphenyl) cyclo And polycarbonates derived from bisphenols such as hexane, 1,1-bis (4-hydroxyphenyl) isobutane and 1,1-bis (4-hydroxyphenyl) ethane.

The (meth) acrylic resin may be, for example, a polymer containing methacrylic acid ester as a main monomer (containing 50% by mass or more), and is preferably a copolymer in which methacrylic acid ester and other copolymerization components are copolymerized.

In one preferable embodiment, (meth) acrylic-type resin contains methyl methacrylate as a copolymerization component, or contains methyl methacrylate and methyl acrylate.

As other copolymerization components other than methyl acrylate, for example, ethyl methacrylate, n-methacrylate, i- or t-butyl, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-methacrylate Methacrylic acid esters other than methyl methacrylate such as ethylhexyl and 2-hydroxyethyl methacrylate;

Acrylic acid esters such as ethyl acrylate, n-, i- or t-butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate;

Methyl 2- (hydroxymethyl) acrylate, methyl 2- (1-hydroxyethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, n-, i- or t-butyl 2- (hydroxymethyl) acrylate Hydroxyalkyl acrylate esters;

Unsaturated acids such as methacrylic acid and acrylic acid;

Halogenated styrenes such as chlorostyrene and bromostyrene;

Substituted styrenes such as vinyltoluene and α-methylstyrene;

Unsaturated nitriles such as acrylonitrile and methacrylonitrile;

Unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride;

Unsaturated imides such as phenylmaleimide and cyclohexyl maleimide;

Monofunctional monomers, such as these, are mentioned.

The other monofunctional monomer may be used alone or in combination of two or more kinds thereof.

A polyfunctional monomer may be used as said other copolymerization component.

Examples of the polyfunctional monomers include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and nonaethylene glycol di. Esterified by the (meth) acrylic acid the both terminal hydroxyl groups of ethylene glycol or its oligomers, such as (meth) acrylate and tetradecaethylene glycol di (meth) acrylate;

Esterification of both terminal hydroxyl groups of propylene glycol or an oligomer thereof with (meth) acrylic acid;

Esters of hydroxyl groups of dihydric alcohols such as neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate and butanediol di (meth) acrylate with (meth) acrylic acid;

Esters of both terminal hydroxyl groups of bisphenol A, alkylene oxide adducts of bisphenol A, or halogen substituents thereof with (meth) acrylic acid;

Esterification of polyhydric alcohols such as trimethylolpropane and pentaerythritol with (meth) acrylic acid and ring-opening addition of an epoxy group of glycidyl (meth) acrylate to these terminal hydroxyl groups;

A ring-opened addition of an epoxy group of glycidyl (meth) acrylate to dibasic acids such as succinic acid, adipic acid, terephthalic acid, phthalic acid, halogen substituents thereof, or alkylene oxide adducts thereof;

Aryl (meth) acrylates; Aromatic divinyl compounds such as divinylbenzene;

Etc. can be mentioned.

Especially, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate are used preferably.

The (meth) acrylic resin may be modified by reaction between functional groups of the copolymer. As said reaction, the deethanol condensation reaction in the polymer chain of the methyl ester group of methyl (meth) acrylate, and the hydroxyl group of methyl 2- (hydroxymethyl) acrylate, the carboxyl group of (meth) acrylic acid, and 2- (hydroxy) The dehydration condensation reaction in the polymer chain with the hydroxyl group of methyl) methyl acrylate, etc. are mentioned.

The glass transition temperature of (meth) acrylic-type resin becomes like this. Preferably it is 80 degreeC or more and 160 degrees C or less. The glass transition temperature is adjusted by adjusting the polymerization ratio of the methacrylic acid ester monomer and the acrylic acid ester monomer, the carbon chain length of each ester group and the kind of functional groups they have, and the polymerization ratio of the polyfunctional monomer to the whole monomer. Controllable.

It is also effective to introduce a ring structure into the main chain of the polymer as a means for increasing the glass transition temperature of the (meth) acrylic resin. It is preferable that ring structure is heterocyclic structure, such as a cyclic acid anhydride structure, a cyclic imide structure, and a lactone structure. Specifically, Cyclic acid anhydride structures, such as a glutaric anhydride structure and a succinic anhydride structure; Cyclic imide structures such as glutarimide structure and succinimide structure; Lactone ring structures, such as butyrolactone and valerolactone, are mentioned.

There exists a tendency which can make glass transition temperature of (meth) acrylic-type resin high, so that content of the ring structure in a principal chain is made large.

The cyclic acid anhydride structure and the cyclic imide structure are introduced by copolymerizing monomers having cyclic structures such as maleic anhydride and maleimide; A method of introducing a cyclic acid anhydride structure by dehydration / methanol condensation reaction after polymerization; It can introduce | transduce by the method etc. which introduce | transduce a cyclic imide structure by making an amino compound react.

Resin (polymer) which has a lactone ring structure prepares the polymer which has a hydroxyl group and ester group in a polymer chain, and then heats the hydroxyl group and ester group in the obtained polymer, such as an organic phosphorus compound as needed by heating. It can obtain by the method of cyclizing condensation in presence of a catalyst and forming a lactone ring structure.

The (meth) acrylic resin and the thermoplastic resin film formed from it may contain the additive as needed. As an additive, a lubricating agent, an antiblocking agent, a heat stabilizer, antioxidant, an antistatic agent, a light resistant agent, an impact resistance improving agent, surfactant, etc. are mentioned, for example.

These additives can be used also when using thermoplastic resins other than (meth) acrylic-type resin as a thermoplastic resin which comprises a thermoplastic resin film.

(Meth) acrylic-type resin may contain the acrylic rubber particle which is an impact modifier from a viewpoint of film forming property to a film, impact resistance of a film, etc. Acrylic rubber particle | grains are particle | grains which have an elastic polymer mainly as an acrylate ester as an essential component, and are the thing of the single layer structure which consists only of this elastic polymer substantially, and the thing of the multilayer structure which makes this elastic polymer one layer.

As an example of the said elastic polymer, the crosslinked elastic copolymer which made alkyl acrylate the main component and copolymerized the other vinylic monomer and crosslinkable monomer which can be copolymerized to this is mentioned.

As alkyl acrylate which becomes a main component of an elastic polymer, C1-C8 or less of alkyl groups, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, is mentioned, for example, Acrylic acid which has a C4 or more alkyl group Alkyl is preferably used.

As another vinylic monomer copolymerizable with the said alkyl acrylate, the compound which has one polymerizable carbon-carbon double bond in a molecule | numerator is mentioned, More specifically, Methacrylic acid ester, such as methyl methacrylate; Aromatic vinyl compounds such as styrene; Vinyl cyan compounds, such as an acrylonitrile, etc. are mentioned.

As said crosslinkable monomer, the crosslinkable compound which has at least 2 polymerizable carbon-carbon double bond in a molecule | numerator is mentioned, More specifically, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, etc. are mentioned. (Meth) acrylates of polyhydric alcohols; Alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate; Divinylbenzene, and the like.

The laminated body of the film which consists of (meth) acrylic-type resin which does not contain a rubber particle, and the film which consists of (meth) acrylic-type resin containing a rubber particle can also be made into the thermoplastic resin film joined to the polarizer 1. Moreover, the (meth) acrylic-type resin layer was formed in the single side | surface or both surfaces of the phase difference expression layer containing resin different from a (meth) acrylic resin, and the phase difference was expressed by the thermoplastic resin film bonded to the polarizer 1 You may.

The thermoplastic resin film may contain the ultraviolet absorber. When applying the polarizing plate 10 to image display apparatuses, such as a liquid crystal display device, the thermoplastic resin film containing a ultraviolet absorber is arrange | positioned at the visual recognition side of an image display element (for example, liquid crystal cell), and deterioration by the ultraviolet-ray of an image display element is carried out. Can be suppressed.

As a ultraviolet absorber, a salicylic acid ester type compound, a benzophenone type compound, a benzotriazole type compound, a cyanoacrylate type compound, a nickel complex salt type compound, etc. are mentioned.

When a thermoplastic resin film is bonded to both surfaces of the polarizer 1, these thermoplastic resin films may be a film comprised from the same thermoplastic resin, or the film comprised from mutually different thermoplastic resins may be sufficient as them. In addition, these thermoplastic resin films may be same or different in thickness, the presence or absence of an additive, its kind, retardation characteristic, etc.

The thermoplastic resin film has a surface treatment layer 2 (coating layer) such as a hard coat layer, an antiglare layer, an antireflection layer, a light diffusion layer, an antistatic layer, an antifouling layer, and a conductive layer on its outer surface (the surface opposite to the polarizer 1). You may be provided.

The thickness of a thermoplastic resin film is 5 micrometers or more and 200 micrometers or less normally, Preferably they are 10 micrometers or more and 120 micrometers or less, More preferably, they are 10 micrometers or more and 85 micrometers or less, More preferably, they are 15 micrometers or more and 60 micrometers or less. The thickness of the thermoplastic resin film may be 50 µm or less, or 40 µm or less. Reducing the thickness of the thermoplastic resin film is advantageous for thinning the polarizing plate 10, and further, the polarizing plate 25 with an adhesive layer, the laminated optical member, and the image display device.

In the surface to which the adhesive agent of a thermoplastic resin film is apply | coated, surface modification processing, such as a saponification process, a plasma processing, a corona treatment, and a primer treatment, may be performed from a viewpoint of adhesive improvement, and surface modification treatment is performed from a viewpoint of simplification of a process. You do not have to do it.

When a thermoplastic resin film is a cellulose acetate type resin film, it is preferable to perform a saponification process from a viewpoint of adhesive improvement. As a saponification process, the method of immersing in aqueous alkali solution, such as sodium hydroxide and potassium hydroxide, is mentioned.

[2-3] Preparation of Polarizing Plate

As an adhesive agent for bonding a thermoplastic resin film to the polarizer 1, an aqueous adhesive agent and an active energy ray curable adhesive agent are mentioned.

As an aqueous adhesive agent, the conventionally well-known adhesive composition using polyvinyl alcohol-type resin or urethane resin as a main component is mentioned, for example.

When using polyvinyl alcohol-type resin as a main component of an adhesive agent, the said polyvinyl alcohol-type resin may be polyvinyl alcohol resins, such as partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, and modified polyvinyl alcohol-type resin.

Polyvinyl alcohol-type resin is a polyvinyl alcohol-type copolymer obtained by saponifying the copolymer of vinyl acetate and the other monomer copolymerizable with this besides the vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate which is a homopolymer of vinyl acetate. You may.

The aqueous adhesive containing polyvinyl alcohol-type resin contains curable components and crosslinking agents, such as a polyvalent aldehyde, a melamine type compound, a zirconia compound, a zinc compound, glyoxal, a glyoxal derivative, and a water-soluble epoxy resin, in order to improve adhesiveness. can do.

As a water-based adhesive agent containing a urethane resin as a main component, the water-based adhesive agent containing the polyester-type ionomer type urethane resin and the compound which has glycidyloxy group is mentioned. The polyester ionomer-type urethane resin is a urethane resin which has a polyester skeleton, in which a small amount of ionic component (hydrophilic component) is introduce | transduced.

An active energy ray curable adhesive agent is an adhesive which hardens | cures by irradiation of active energy rays, such as an ultraviolet-ray, visible light, an electron beam, and X-rays. When using an active energy ray curable adhesive agent, the adhesive bond layer which the polarizing plate 10 has is a hardened | cured material layer of the said adhesive agent.

The active energy ray curable adhesive may be an adhesive containing an epoxy compound that is cured by cationic polymerization as a curable component, and is preferably an ultraviolet curable adhesive containing such an epoxy compound as a curable component. An epoxy compound means the compound which has an average of 1 or more, preferably 2 or more epoxy groups in a molecule | numerator. An epoxy compound may use only 1 type and may use 2 or more types together.

As an epoxy-type compound, Hydrogenated epoxy-type compound (glycidyl ether of the polyol which has an alicyclic ring) obtained by making epichlorohydrin react with the alicyclic polyol obtained by performing a hydrogenation reaction to the aromatic ring of an aromatic polyol; Aliphatic epoxy compounds such as polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof; Alicyclic epoxy-type compounds etc. which are epoxy-type compounds which have one or more epoxy groups couple | bonded with an alicyclic ring in a molecule | numerator are mentioned.

An active energy ray curable adhesive agent may contain a (meth) acrylic-type compound which is radically polymerizable instead of or with the said epoxy-type compound as a curable component. As a (meth) acrylic-type compound, (meth) acrylate monomer which has 1 or more (meth) acryloyloxy group in a molecule | numerator; It is obtained by making 2 or more types of functional group containing compounds react, and (meth) acryloyloxy group containing compounds, such as (meth) acrylate oligomer which has at least 2 (meth) acryloyloxy group in a molecule | numerator, are mentioned.

When an active energy ray curable adhesive agent contains the epoxy-type compound hardened | cured by cationic polymerization as a curable component, it is preferable to contain a photocationic polymerization initiator. As a photocationic polymerization initiator, For example, Aromatic diazonium salt; Onium salts such as aromatic iodonium salts and aromatic sulfonium salts; Iron-Allene complex etc. are mentioned.

When an active energy ray curable adhesive agent contains radically polymerizable components, such as a (meth) acrylic-type compound, it is preferable to contain a radical photopolymerization initiator. As an optical radical polymerization initiator, an acetophenone type initiator, a benzophenone type initiator, a benzoin ether type initiator, a thioxanthone type initiator, a xanthone, a fluorenone, camphor quinone, benzaldehyde, anthraquinone, etc. are mentioned, for example.

Bonding of the polarizer 1 and the thermoplastic resin film coats an adhesive on the bonding surface of the polarizer 1 and / or the bonding surface of the thermoplastic resin film, or injects the adhesive between the polarizer 1 and the thermoplastic resin film, The two films may be superimposed through a layer of the adhesive, and may be bonded to each other by pressing from above and below using a bonding roll or the like.

Various coating methods, such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater, can be used for formation of an adhesive layer. The polarizer 1 and the thermoplastic resin film may be continuously fed so that the bonding surface of the both are inward, while the adhesive may be cast therebetween.

Before applying the adhesive, easy adhesion treatment such as saponification treatment, corona discharge treatment, plasma treatment, flame treatment, primer treatment, anchor coating treatment, etc. to one or both of the bonding surfaces of the polarizer 1 and the thermoplastic resin film (surface) Activation process).

When using an active energy ray curable adhesive agent, after drying the layer of an adhesive agent as needed, an active energy ray is irradiated to harden a layer of an adhesive agent.

The light source used for irradiating active energy rays may be ultraviolet rays, electron beams, X-rays or the like. In particular, low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultrahigh pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps and the like which have a light emission distribution at a wavelength of 400 nm or less are suitably used.

In the polarizing plate 10 obtained, the thickness of the adhesive bond layer formed of an aqueous adhesive is 10 nm or more and 10 micrometers or less, Preferably it is 20 nm or more and 5 micrometers or less, More preferably, it is 30 nm or more and 1 micrometer or less. More preferably, they are 40 nm or more and 500 nm or less.

The thickness of the adhesive bond layer formed from an active energy ray curable adhesive agent is 10 nm or more and 20 micrometers or less, Preferably it is 100 nm or more and 10 micrometers or less, More preferably, it is 500 nm or more and 5 micrometers or less.

In the case where the thermoplastic resin film is bonded to both surfaces of the polarizer 1, the two adhesive layers may be the same or different in thickness.

[2-4] Other components of the polarizing plate

The polarizing plate 10 may be provided with an optical functional film other than the polarizer 30 for imparting a desired optical function, and a suitable example thereof is the same as that of the retardation film 7 shown in FIGS. 3 and 4. It is a retardation film.

As mentioned above, although the thermoplastic resin film which is a protective film may also serve as retardation film, you may laminate | stack a retardation film separately from a thermoplastic resin film. In the latter case, retardation film can be laminated | stacked on the outer surface of a thermoplastic resin film through an adhesive layer or an adhesive bond layer.

In addition, a retardation film may be laminated instead of the thermoplastic resin film (see FIG. 3). In this case, retardation film can be laminated | stacked on the surface of the polarizer 1 via an adhesive layer or an adhesive bond layer.

As a retardation film, Birefringent film comprised from the stretched film of the thermoplastic resin which has transparency; A film in which the discotic liquid crystal or the nematic liquid crystal is fixed in alignment; The thing etc. which the said liquid crystal layer was formed on the base film are mentioned.

The base film is usually a film made of a thermoplastic resin, and an example of the thermoplastic resin is a cellulose ester-based resin such as triacetyl cellulose.

As a thermoplastic resin which forms a birefringent film, what was described about the thermoplastic resin film can be used.

Examples of other optical functional films (optical members) that may be included in the polarizing plate 10 include a light collecting plate, a brightness enhancing film, a reflective layer (reflective film), a semi-transmissive reflective layer (semi-transmissive reflective film), a light diffusing layer (light diffusing film), and the like. to be. These are generally formed when the polarizing plate 10 is a polarizing plate arranged on the back side (backlight side) of the liquid crystal cell.

The light collecting plate is used for the purpose of optical path control and the like, and may be a prism array sheet, a lens array sheet, a dot laying sheet, or the like.

The brightness enhancement film is used for the purpose of improving the brightness in the liquid crystal display device to which the polarizing plate 10 is applied. Specifically, a plurality of thin film films having different refractive anisotropy from each other are laminated to support a reflective polarizing separation sheet designed to generate anisotropy in reflectance, an oriented film of cholesteric liquid crystal polymer, or an alignment liquid crystal layer thereof on a base film. Circularly polarized light separating sheets; and the like.

The reflective layer, the semi-transmissive reflective layer, and the light diffusing layer are formed in order to make the polarizing plate 10 an optical member of reflective, semi-transmissive, and diffuse type. A reflective polarizing plate is used for a liquid crystal display device of the type which reflects and displays incident light from the viewer side, and since a light source such as a backlight can be omitted, it is easy to thin the liquid crystal display device. The semi-transmissive polarizing plate is used for a liquid crystal display device of a type which displays reflection light in a dark place and light from a backlight in a dark place. In addition, a diffusion type polarizing plate is used for the liquid crystal display device which provided light diffusivity and suppressed display defects, such as moire. The reflection layer, the transflective reflection layer, and the light diffusion layer can be formed by a known method.

The polarizing plate 10 may include a protective film for protecting the surface (typically, the thermoplastic resin film surface) on the side opposite to the side on which the first pressure sensitive adhesive layer 20 is laminated. After a polarizing plate 25 with an adhesive layer is bonded to optical members, such as an image display element, a protective film is peeled off with the adhesive layer which it has, for example.

A protect film is comprised from a base film and the adhesive layer laminated | stacked on it, for example.

The resin constituting the base film may be, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, or a thermoplastic resin such as polycarbonate resin. have. Preferably, it is polyester resin, such as polyethylene terephthalate.

[2-5] Curl force of polarizing plate

Since the present invention is advantageous for improving the curl resistance of the laminated optical member, it is particularly effective when the polarizing plate 10 is easily curled.

Easiness of curling of the polarizing plate 10 can be evaluated by the maximum curl force in 80 degreeC, for example. The maximum curl force at 80 ° C. is measured according to the method described in the section of Examples described later.

500 mN or more may be sufficient as the maximum curl force in 80 degreeC of the polarizing plate 10 which the polarizing plate 25 with an adhesive layer has. Even in this case, according to the present invention, it is possible to provide a laminated optical member having good warpage resistance.

The maximum curl force at 80 ° C of the polarizing plate 10 of the polarizing plate 25 with the pressure-sensitive adhesive layer may be 700 mN or more, may be 1000 mN or more, 1200 mN or more, or 1500 mN or more. The maximum curl force at 80 degrees C of the polarizing plate 10 which the polarizing plate 25 with an adhesive layer has is 10000 mN or less normally, may be 5000 mN or less, 3000 mN or less, and 2000 mN or less.

As an example of the structure of the polarizing plate 10 which is easy to generate | occur | produce curl, the structure of any one of the following (a)-(h) is mentioned, for example.

(a) a configuration in which the polarizer 1 is thick,

(b) a thin thermoplastic film,

(c) a constitution in which the adhesive layer interposed between the polarizer 1 and the thermoplastic resin film is a cured product layer of an active energy ray curable adhesive,

(d) the structure in which the thermoplastic resin film is bonded only to the single side | surface of the polarizer 1,

(e) the structure (resin type, thickness, presence or absence of a surface treatment layer, etc.) of the thermoplastic resin film bonded to both surfaces of the polarizer 1 differ from each other,

(f) the structure in which the adhesive bond layers for bonding a thermoplastic resin film to both surfaces of the polarizer 1 are formed of heterogeneous adhesives,

(g) A structure in which a thermoplastic resin film is bonded to both surfaces of the polarizer 1, and another optical functional film is bonded on one thermoplastic resin film,

(h) In addition, the structure in which the total number of the film and layer in one side differs from the total number of the film and layer in the other side based on the polarizer 1.

Moreover, curling tends to generate | occur | produce so that the polarizing plate 10 is large in size. From the viewpoint of the maximum curling force at 80 ° C described above, the polarizing plate 10 is a sheet of a polarizing plate having a rectangular shape or a substantially rectangular shape, preferably having a size of 100 mm × 40 mm or more, and 150 mm × 40 It is more preferable to have a size of mm or more. The size of the polarizing plate 10 is 1650 mm x 930 mm or less, for example, Preferably it is 1430 mm x 810 mm or less.

[3] pressure-sensitive adhesive layer

The adhesive layer (1st adhesive layer 20) which comprises the polarizing plate 25 with an adhesive layer is formed from an adhesive composition.

[3-1] (meth) acrylic resin

The pressure-sensitive adhesive composition is a pressure-sensitive adhesive layer in the optical properties (transparency, polarization characteristics, etc.) of the polarizing plate with a pressure-sensitive adhesive layer, laminated resistance of the laminated optical member which is a laminate of the polarizing plate with a pressure-sensitive adhesive layer and other optical members, heat resistance It is preferable to contain (meth) acrylic-type resin from a viewpoint of adhesiveness, etc. of the 1st adhesive layer 20 and another optical member. An adhesive composition can contain 1 type (s) or 2 or more types (meth) acrylic-type resin.

In this specification, "(meth) acryl" means acryl and / or methacryl, and "(meth)" when it is called (meth) acrylate etc. is also the same.

The heat-resistant durability is such as lifting or peeling at the interface between the pressure-sensitive adhesive layer and other optical members, foaming of the pressure-sensitive adhesive layer, and the like, which may occur when the laminated optical member is placed at a high temperature, or is placed in an environment where high temperature and low temperature are repeated. It means tolerance to the problem.

The (meth) acrylic resin has an optical characteristic (transparency, polarization characteristic, etc.) of the polarizing plate with a pressure-sensitive adhesive layer, the warpage resistance and heat resistance of the laminated optical member, and / or the pressure-sensitive adhesive layer in the laminated optical member and other optical members. In view of adhesiveness, the following formula (I):

It is preferable that it is a polymer containing the structural unit derived from the (meth) acrylic acid ester represented by as a main component. A main component means that content which occupies for all the structural units which comprise (meth) acrylic-type resin is 50 mass% or more.

In said Formula (I), R <^1> represents a hydrogen atom or a methyl group, R <^2> is a C1-C14 alkyl group or C1-C10 alkoxy group which may be substituted by the C1-C10 alkoxy group. The aralkyl group which has C7 or more and 21 or less which may be substituted is shown. Carbon number of an aralkyl group in the case where an aralkyl group is substituted by the alkoxy group is carbon number except the carbon atom of the alkoxy group.

R ² is more preferably an alkyl group having 1 or less than 10 may be substituted with an alkoxy having a carbon number of less good than 114 preferably an alkyl group or less, or more C 1 is not substituted with the alkoxy 14.

As (meth) acrylic acid ester represented by Formula (I), for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and n- (meth) acrylate (Meth) acrylic-acid alkylester which has linear alkylester parts, such as octyl and lauryl (meth) acrylate; (Meth) acrylic-acid alkylester etc. which have branched alkyl ester parts, such as isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isooctyl (meth) acrylate, are mentioned.

When R <^2> is an alkyl group substituted by the alkoxy group, ie, when (R <^2>) is an alkoxyalkyl group, as (meth) acrylic acid ester represented by Formula (I), it is (meth) acrylic acid 2-methoxyethyl, ( Ethoxy methyl methacrylate, etc. are mentioned.

(Meth) acrylic acid benzyl etc. are mentioned as (meth) acrylic acid ester represented by Formula (I) in the case where R <^2> is a C7-C21 or less aralkyl group.

The (meth) acrylic acid ester represented by Formula (I) may be used individually by 1 type, or may use 2 or more types together. Especially, it is preferable that (meth) acrylic acid ester contains n-butyl acrylate.

(Meth) acrylic-type resin contains the structural unit derived from n-butyl acrylate among all the structural units which comprise this, Preferably it contains 50 mass% or more, More preferably, contains 55 mass% or more. Content of the structural unit derived from n-butyl acrylate is 90 mass% or less normally in all the structural units which comprise (meth) acrylic-type resin, Preferably it is 85 mass% or less, More preferably, it is 80 mass% or less More preferably, it is 75 mass% or less.

In addition to n-butyl acrylate, you may use together the (meth) acrylic acid ester represented by Formula (I) other than that. For example, it is preferable that (meth) acrylic-type resin contains the structural unit derived from n-butyl acrylate, and the structural unit derived from methyl acrylate. When (meth) acrylic-type resin contains the structural unit derived from n-butyl acrylate, and the structural unit derived from methyl acrylate, content of the structural unit derived from n-butyl acrylate is as above-mentioned, and the structural unit derived from methyl acrylate Content is 1 mass% or more and 50 mass% or less normally in all the structural units which comprise (meth) acrylic-type resin, Preferably they are 5 mass% or more and 45 mass% or less, More preferably, they are 10 mass% or more and 40 mass%. % Or less

Content of the structural unit derived from the (meth) acrylic acid ester represented by Formula (I) is the optical characteristic (transparency, polarization characteristic, etc.) of the polarizing plate with an adhesive layer, the warpage resistance and heat resistance durability of a laminated optical member, and / or lamination | stacking From the viewpoint of the adhesiveness between the pressure-sensitive adhesive layer in the optical member and the other optical member, etc., the total constituent units constituting the (meth) acrylic resin are preferably 60% by mass or more and less than 100% by mass, more preferably 70 It is 9 mass% or less by mass% or more, More preferably, it is 80 mass% or more and 99.6 mass% or less.

(Meth) acrylic-type resin can contain the structural unit derived from the (meth) acrylic-type monomer which has a hydroxyl group. Inclusion of this structural unit can be advantageous in increasing the warpage resistance and heat resistance of the laminated optical member, and / or the adhesiveness between the pressure-sensitive adhesive layer in the laminated optical member and other optical members.

As a (meth) acrylic-type monomer which has a hydroxyl group, the (meth) acrylic acid ester which has a hydroxyl group is mentioned.

Examples of the (meth) acrylic acid ester having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and 2- (2-hydroxy) methacrylate. Hydroxyethoxy) ethyl, 2- or 3-chloro-2-hydroxypropyl (meth) acrylic acid, diethylene glycol mono (meth) acrylate, and the like.

Content of the structural unit derived from the (meth) acrylic-type monomer which has a hydroxyl group is a thing such as the curvature resistance of a laminated optical member, heat resistance, and / or workability of the adhesive layer in a laminated optical member, and adhesiveness with another optical member, etc. From a viewpoint, it is 0.1 mass% or more and 5 mass% or less in all the structural units which comprise (meth) acrylic-type resin, More preferably, they are 0.5 mass% or more and 4 mass% or less.

(Meth) acrylic-type resin can contain the structural unit derived from the monomer which has other polar functional groups other than the (meth) acrylic-type monomer which has a hydroxyl group. The monomer having another polar functional group is preferably a (meth) acrylic monomer having another polar functional group.

As a polar functional group which the monomer which has another polar functional group has, a carboxyl group (free carboxyl group), an amino group, a heterocyclic group (for example, an epoxy group), an amide group, etc. are mentioned.

As a monomer which has another polar functional group,

Monomers having carboxyl groups such as (meth) acrylic acid and β-carboxyethyl (meth) acrylate ((meth) acrylic monomers having carboxyl groups);

(Meth) acryloyl morpholine, vinyl caprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth) acrylate, caprolactone modified tetrahydrofurfuryl (meth) acrylate, 3 Monomers having a heterocyclic group such as, 4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate and 2,5-dihydrofuran;

Monomer which has an amino group different from heterocycles, such as aminoethyl (meth) acrylate, N, N- dimethylaminoethyl (meth) acrylate, and dimethylaminopropyl (meth) acrylate

Etc. can be mentioned.

The monomer which has another polar functional group may be used individually by 1 type, or may use 2 or more types together.

Content of the structural unit derived from the monomer which has another polar functional group is a viewpoint of adhesiveness of the adhesive layer in a laminated optical member, heat resistance, and / or a laminated optical member, and other optical members, etc. In all the structural units which comprise acrylic resin, Preferably they are 0.1 mass% or more and 5 mass% or less, More preferably, they are 0.5 mass% or more and 3 mass% or less.

The (meth) acrylic resin is derived from a monomer having one olefinic double bond and at least one aromatic ring in the molecule (except for the above formula (I) or a monomer having the polar functional group). It may further include a structural unit.

The inclusion of a structural unit derived from a monomer having one olefinic double bond and at least one aromatic ring in the molecule can be advantageous in view of effectively suppressing the occurrence of white spots and color unevenness in the laminated optical member. .

As a monomer which has one olefinic double bond and at least 1 aromatic ring in a molecule | numerator, the (meth) acrylic-type monomer which has an aromatic ring is mentioned.

As a (meth) acrylic-type monomer which has an aromatic ring, in addition to neopentyl glycol benzoate (meth) acrylate, following formula (II):

(Meth) acrylic acid ester which has aryloxyalkyl groups, such as the phenoxyethyl group containing (meth) acrylic acid ester represented by these, Preferably it is (meth) acrylic acid ester which has an aryloxyalkyl group.

In formula (II), R <^3> represents a hydrogen atom or a methyl group, i represents the integer of 1 or more and 8 or less, and R <^4> represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group. When R ⁴ is an alkyl group, the carbon number may be 1 or more and about 9 or less, and in the case of an aralkyl group, the carbon number may be about 7 or more and about 11 or less, and in the case of an aryl group, the carbon number may be about 6 to about 10 or less.

Examples of the alkyl group having 1 to 9 carbon atoms that constitute R ⁴ in formula (II) include methyl group, butyl group, nonyl group, and the like. As aralkyl group having 7 to 11 carbon atoms, benzyl group, phenethyl group, naphthylmethyl group, etc. Examples of the aryl group having 6 to 10 carbon atoms include phenyl group, tolyl group, and naphthyl group.

As a specific example of the phenoxyethyl group containing (meth) acrylic acid ester represented by Formula (II), for example, (meth) acrylic acid 2-phenoxyethyl, (meth) acrylic acid 2- (2-phenoxyethoxy) ethyl, ethylene oxide (Meth) acrylic acid ester of modified nonylphenol, 2- (o-phenylphenoxy) ethyl, and the like.

Phenoxyethyl group-containing (meth) acrylic acid ester may be used individually by 1 type, or may use 2 or more types together.

Especially, phenoxyethyl group containing (meth) acrylic acid ester is (meth) acrylic acid 2-phenoxyethyl, (meth) acrylic acid 2- (o-phenylphenoxy) ethyl, and (meth) acrylic acid 2- (2-phenoxy) It is preferable to contain 1 type (s) or 2 or more types chosen from the group which consists of ethoxy) ethyl, and (meth) acrylic acid 2- (o-phenylphenoxy) ethyl and (meth) acrylic acid 2- (2-phenoxy It is more preferable to include 1 type or 2 types chosen from the group which consists of oxy) ethyl.

Content of the structural unit derived from the monomer which has one olefinic double bond and at least 1 aromatic ring in a molecule | numerator is a (meth) acrylic-type resin from a viewpoint which suppresses generation | occurrence | production of the white spot and color unevenness in a laminated optical member effectively. It is 1 mass% or more and 20 mass% or less in all the structural units which comprise (V), More preferably, they are 5 mass% or more and 15 mass% or less.

The (meth) acrylic resin is a monomer other than a monomer having one olefinic double bond and at least one aromatic ring in the (meth) acrylic acid ester of the formula (I), the monomer having a polar functional group, and the molecule described above (hereinafter, " Other monomers "may also be included.).

As other monomers, a structural unit derived from the (meth) acrylic acid ester which has an alicyclic structure in a molecule | numerator, a structural unit derived from a styrene monomer, the structural unit derived from a vinylic monomer, and a some (meth) acryl in a molecule | numerator The structural unit derived from the monomer which has a diary, the structural unit derived from a (meth) acrylamide monomer, etc. are mentioned.

Other monomers may be used individually by 1 type, and may use 2 or more types together.

Containing the structural unit derived from another monomer, especially the structural unit derived from the (meth) acrylamide monomer, has an optical member different from the pressure-sensitive adhesive layer in the bending resistance and heat resistance durability of the laminated optical member, and / or the laminated optical member. It may be advantageous in increasing the adhesiveness with and the like.

The alicyclic structure in the (meth) acrylic acid ester which has an alicyclic structure in a molecule | numerator is a cycloparaffin structure of carbon number 5 or more normally, Preferably it is 5 or more and about 7 or less.

Examples of the (meth) acrylic acid ester having an alicyclic structure include isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclododecyl (meth) acrylate, and methylcyclohexyl (meth) acrylate. , Trimethylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclohexylphenyl (meth) acrylate, cyclohexyl (alpha)-ethoxy acrylate, etc. are mentioned.

As a styrene-type monomer, Styrene; Alkyl styrene such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, octyl styrene; Halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodine styrene; Nitrostyrene, acetyl styrene, methoxy styrene, divinylbenzene, etc. are mentioned.

Examples of the vinyl monomers include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; Vinyl halides such as vinyl chloride and vinyl bromide; Vinylidene halides such as vinylidene chloride; Nitrogen-containing aromatic vinyls such as vinylpyridine, vinylpyrrolidone and vinyl carbazole; Conjugated diene monomers such as butadiene, isoprene and chloroprene; Acrylonitrile, methacrylonitrile, etc. are mentioned.

As a monomer which has a some (meth) acryloyl group in a molecule | numerator, 1, 4- butanediol di (meth) acrylate, 1, 6- hexanediol di (meth) acrylate, and 1, 9- nonane diol di (meth) Two (meth) in the molecule, such as acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate Monomers having acryloyl group; The monomer etc. which have three (meth) acryloyl groups in molecules, such as a trimethylol propane tri (meth) acrylate, are mentioned.

As a (meth) acrylamide monomer, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (4-hydroxybutyl) (meth) acrylamide, N- (5-hydroxypentyl) (meth) acrylamide, N- (6-hydroxyhexyl) (meth) acrylamide, N, N-dimethyl (meth ) Acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N- (3-dimethylaminopropyl) (meth) acrylamide, N- (1,1-dimethyl- 3-oxobutyl) (meth) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl] (meth) acrylamide, 2-acryloylamino-2-methyl-1-propane Sulfonic acid, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) (meth) acrylamide, N- (propoxymethyl) (meth) acrylamide, N- (1-methylethoxymethyl) (meth ) Acrylamide, N- (1-methylpropoxymethyl) (meth) acrylamide, N- (2-methylprop Methyl) (meth) acrylamide [alias: N- (isobutoxymethyl) (meth) acrylamide], N- (butoxymethyl) (meth) acrylamide, N- (1,1-dimethylethoxymethyl) (Meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N- (2-ethoxyethyl) (meth) acrylamide, N- (2-propoxyethyl) (meth) acrylamide , N- [2- (1-methylethoxy) ethyl] (meth) acrylamide, N- [2- (1-methylpropoxy) ethyl] (meth) acrylamide, N- [2- (2-methyl Propoxy) ethyl] (meth) acrylamide [alias: N- (2-isobutoxyethyl) (meth) acrylamide], N- (2-butoxyethyl) (meth) acrylamide, N- [2- ( 1,1-dimethylethoxy) ethyl] (meth) acrylamide and the like. Especially, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, N- (2-methylprop Foxymethyl) acrylamide is preferably used.

The (meth) acrylamide monomer is preferably alkyl that may be substituted with an alkoxy group from the viewpoints of warpage resistance and heat resistance of the laminated optical member, adhesiveness between the pressure-sensitive adhesive layer in the laminated optical member, and other optical members. Meth) acrylamide monomers.

In the alkyl (meth) acrylamide monomer which may be substituted with an alkoxy group, the carbon number of the alkoxy group is preferably 1 or more and 10 or less, and preferably the carbon number of the alkyl group is 1 or more and 14 or less. Carbon number of the alkyl group in the case where an alkyl group is substituted by the alkoxy group is carbon number except the carbon atom of the alkoxy group.

As an alkyl (meth) acrylamide monomer which may be substituted by the alkoxy group, following formula (III):

The alkoxyalkyl (meth) acrylamide monomer represented by this is mentioned.

In Formula (III), R <^5> represents a hydrogen atom or a methyl group, and R <^6> represents a C1-C14 alkyl group. n represents the integer of 1-8.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-hexyl group, n-heptyl group and n-octyl group.

n becomes like this. Preferably it is 1 or more and 6 or less.

Content of the structural unit (especially (meth) acrylamide monomer) derived from other monomers is warp resistance of a laminated optical member, heat resistance, and / or adhesiveness of the adhesive layer in another laminated optical member, and other optical members, etc. In view of the above, of all the structural units constituting the (meth) acrylic resin, preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.2% by mass or more and 10% by mass or less, still more preferably 0.3 mass It is 5 mass parts or less in% or more.

(Meth) acrylic-type resin originates in the (meth) acrylic-type monomer which has a carboxyl group from a viewpoint of the curvature resistance, heat resistance durability of a laminated optical member, and / or adhesiveness of the adhesive layer in another laminated optical member, and another optical member. It is preferable that the structural unit and the structural unit derived from the alkoxyalkyl (meth) acrylamide monomer are included.

The total content of the structural unit derived from the (meth) acrylic monomer having a carboxyl group and the structural unit derived from the alkoxyalkyl (meth) acrylamide monomer is the curvature resistance and heat resistance durability of the laminated optical member and / or the laminated optical member. From the viewpoint of the adhesiveness between the pressure-sensitive adhesive layer and other optical members, and the like, in the total constituent units constituting the (meth) acrylic resin, the content is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.2% by mass or more and 10% by mass. It is% or less, More preferably, it is 0.3 mass% or more and 4 mass parts or less.

It is preferable that the weight average molecular weight (Mw) of standard polystyrene conversion by gel permeation chromatography (GPC) exists in the range of 500,000 or more and 2 million or less, and (meth) acrylic-type resin is in the range of 600,000 or more and 1.8 million or less It is more preferable that there is. The pressure-sensitive adhesive composition containing a (meth) acrylic resin having Mw within the above range is advantageous in view of the bending resistance of the laminated optical member, the heat resistance, and / or the handling properties of the (meth) acrylic resin at the time of preparing the pressure-sensitive adhesive composition. Can be done.

The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is usually 2 or more and about 10 or less, preferably 3 or more and 8 or less.

(Meth) acrylic-type resin can be manufactured by well-known methods, such as solution polymerization method, block polymerization method, suspension polymerization method, and emulsion polymerization method, for example. In manufacture of (meth) acrylic-type resin, a polymerization initiator is used normally. A polymerization initiator can be used in about 0.001 mass part or more and about 5 mass parts or less with respect to a total of 100 mass parts of all the monomers used for manufacture of (meth) acrylic-type resin. In addition, you may manufacture (meth) acrylic-type resin by the method of advancing superposition | polymerization with active energy rays, such as an ultraviolet-ray.

As a polymerization initiator, a thermal polymerization initiator, a photoinitiator, etc. are used.

As a photoinitiator, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone etc. are mentioned, for example.

Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), and 1,1'-azobis (cyclohexane-1-carbonitrile). ), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'- Azo compounds, such as azobis (2-methyl propionate) and 2,2'- azobis (2-hydroxymethyl propionitrile); Lauryl peroxide, tert-butylhydroperoxide, benzoyl peroxide, tert-butylperoxybenzoate, cumene hydroperoxide, diisopropylperoxydicarbonate, dipropylperoxydicarbonate, tert-butylperoxy neodecanoate organic peroxides such as tert-butylperoxy pivalate and (3,5,5-trimethylhexanoyl) peroxide; Inorganic peroxides such as potassium persulfate, ammonium persulfate and hydrogen peroxide; and the like.

Moreover, the redox type initiator etc. which used a peroxide and a reducing agent together can also be used as a polymerization initiator.

As a manufacturing method of (meth) acrylic-type resin, the solution polymerization method is preferable also in the method shown above. As an example of the solution polymerization method, the monomer and organic solvent used are mixed, and a thermal polymerization initiator is added in nitrogen atmosphere, and it is 40 degreeC or more and about 90 degrees C or less, Preferably it is 50 degreeC or more and about 80 degrees C or less, 15 hours or more It stirs for about an hour or less. In order to control reaction, a monomer and a thermal polymerization initiator may be added continuously or intermittently during superposition | polymerization, or may be added in the state dissolved in the organic solvent.

As an organic solvent, For example, aromatic hydrocarbons, such as toluene and xylene; Esters such as ethyl acetate and butyl acetate; Aliphatic alcohols such as propyl alcohol and isopropyl alcohol; Ketones, such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, etc. are mentioned.

[3-2] crosslinking agent

The pressure-sensitive adhesive composition may further contain a crosslinking agent. A crosslinking agent is a compound which reacts with the polar functional group etc. in (meth) acrylic-type resin, and crosslinks (meth) acrylic-type resin.

As a crosslinking agent, the crosslinking agent chosen from an isocyanate type compound, an epoxy type compound, an aziridine type compound, a metal chelate type compound, etc. is mentioned.

Among them, the isocyanate compound, the epoxy compound, and the aziridine compound have at least two functional groups in the molecule that can react with the polar functional group and the like in the (meth) acrylic resin.

A crosslinking agent may be used individually by 1 type, and may use 2 or more types together.

An isocyanate type compound is a compound which has at least 2 isocyanate group (-NCO) in a molecule | numerator.

As an isocyanate type compound, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, for example. And triphenylmethane triisocyanate. Moreover, the adduct body which made polyol, such as glycerol and a trimethylol propane, react with these isocyanate compounds, and what made an isocyanate compound into dimer, trimer, etc. can also be a crosslinking agent.

You may use it in mixture of 2 or more types of isocyanate compounds.

An epoxy compound is a compound which has at least 2 epoxy group in a molecule | numerator.

Examples of the epoxy compound include bisphenol A epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, and 1,6-hexanediol di. Glycidyl ether, trimethylolpropanetriglycidyl ether, N, N-diglycidylaniline, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N , N'-diglycidylaminomethyl) cyclohexane, etc. may be mentioned.

You may mix and use 2 or more types of epoxy compounds.

The aziridine-based compound is a compound having at least two three-membered ring skeletons containing one nitrogen atom and two carbon atoms, also called ethyleneimine.

As the aziridine-based compound, for example, diphenylmethane-4,4'-bis (1-aziridinecarboxamide), toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine, isophthalo Ylbis-1- (2-methylaziridine), tris-1-aziridinylphosphine oxide, hexamethylene-1,6-bis (1-aziridinecarboxamide), trimethylolpropane-tris-β- Aziridinyl propionate, tetramethylol methane- tris- (beta)-aziridinyl propionate, etc. are mentioned.

You may mix and use 2 or more types of aziridine-type compounds.

Examples of the metal chelate compound include compounds in which acetylacetone and ethyl acetoacetate are coordinated with polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium. have.

It is also possible to use a mixture of two or more metal chelate compounds.

Especially, an isocyanate type compound can be advantageous in improving the curvature resistance, heat resistance, and / or adhesiveness of the adhesive layer in another laminated optical member, and other optical members.

Among the isocyanate compounds, xylylene diisocyanate, tolylene diisocyanate or hexamethylene diisocyanate; Adducts which made these isocyanate compounds react polyol, such as glycerol and a trimethylol propane; Dimers, trimers, and the like of these isocyanate compounds or mixtures thereof; 2 or more types of mixtures of the above isocyanate type compound, etc. are used preferably.

As a suitable isocyanate compound, tolylene diisocyanate, adduct having a polyol reacted with tolylene diisocyanate, a dimer of tolylene diisocyanate, and a trimer of tolylene diisocyanate, and also a polyol to hexamethylene diisocyanate and hexamethylene diisocyanate The adduct body which reacted, the dimer of hexamethylene diisocyanate, and the trimer of hexamethylene diisocyanate are mentioned.

Content of the crosslinking agent in an adhesive composition is 0 mass part or more and 5 mass parts or less normally with respect to 100 mass parts of (meth) acrylic-type resin, Preferably they are 0 mass part or more and 2 mass parts or less. When an adhesive composition contains a crosslinking agent, the lower limit of the content is 0.05 mass part with respect to 100 mass parts of (meth) acrylic-type resin, for example.

[3-3] Ionic Compound

The pressure-sensitive adhesive composition may further contain an ionic compound as an antistatic agent for imparting antistatic property to the pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer 20). An ionic compound is a compound which has an inorganic cation or an organic cation and an inorganic anion or an organic anion.

You may use 2 or more types of ionic compounds.

Examples of the inorganic cations include alkali metal ions such as lithium cations [Li ⁺ ], sodium cations [Na ⁺ ], potassium cations [K ⁺ ], beryllium cations [Be ^{2 +} ], magnesium cations [Mg ²⁺ ] and calcium. and the like alkaline earth metal ion such as a cation [Ca ^{2 +].}

As an organic cation, an imidazolium cation, a pyridinium cation, a pyrrolidinium cation, an ammonium cation, a sulfonium cation, a phosphonium cation, etc. are mentioned, for example.

Of the above cationic components, the organic cationic component is preferably used because of its excellent compatibility with the pressure-sensitive adhesive composition. Among the organic cation components, in particular, the pyridinium cation and the imidazolium cation are preferably used from the viewpoint of being difficult to charge when peeling the separate film formed on the pressure sensitive adhesive layer (first pressure sensitive adhesive layer 20).

Examples of the inorganic anion include chloride anion [Cl ⁻ ], bromide anion [Br ⁻ ], iodide anion [I ⁻ ], tetrachloroaluminate anion [AlCl ₄ ⁻ ], heptachlorodialuminate anion [Al ₂ Cl ₇ ^-], anion [BF ₄ tetrafluoro ^-], phosphate anion [PF ₆ hexafluoro ^-], perchlorate anion [ClO ₄ ^-], nitrate anions [NO ₃ ^-], are three anion hexafluoro [AsF ₆ ^-], antimonate anion hexafluorophosphate [SbF ₆ ^-], hexafluoro niobate anions [NbF ₆ ^-], tantalum anion hexafluorophosphate [TaF ₆ ^-], DC Ana imide anion [(CN ) ₂ N ^-, and the like].

Examples of the organic anion include acetate anion [CH ₃ COO ⁻ ], trifluoroacetate anion [CF ₃ COO ⁻ ], methanesulfonate anion [CH ₃ SO ₃ ⁻ ], trifluoromethanesulfonate anion [CF ₃ SO ^_3], p- toluenesulfonate anion _{[p-CH 3 C 6 H 4} SO 3 - ], a bis (alkylsulfonyl fluorophenyl) imide anion [(FSO _{2) 2} N ^-], methane-bis (trifluoro sulfonyl) imide anion _{[(CF 3 SO 2) 2 N} - ], methanesulfonyl as tris (trifluoromethyl) meth arsenide anion _{[(CF 3 SO 2) 3 C} - ], dimethyl phosphinate anion [(CH _{3) 2} POO ^-], (poly) fluoride anion [F (HF) _n as ^{hydro-fluoro-]} (n is 1 to 3 or less), thiocyanate anion [SCN ^-], butane sulfonate anion perfluoro [ C ₄ F ₉ SO ₃ ^-], bis (pentafluoro ethane sulfonyl) imide anion _{[(C 2 F 5 SO 2)} 2 N - ], perfluoro butanoate anion [C ₃ F ₇ COO ^-], (trifluoromethane sulfonyl) (trifluoromethanesulfonyl carbonyl) imide anion _{[(CF 3 SO 2) (CF} 3 CO) N - ], perfluoro-1,3-propane -, and the like, carbonate anions [CO ₃ ^2-] [di-sulfonate anion ^{_{- - O 3 s (CF 2}} ) 3 SO 3 ].

Among the anion components described above, the anion component containing a fluorine atom is particularly preferably used because it provides an ionic compound having excellent antistatic performance. As an anion component containing a fluorine atom, a bis (fluorosulfonyl) imide anion, a hexafluoro phosphate anion, or a bis (trifluoromethanesulfonyl) imide anion is mentioned.

The specific example of an ionic compound can be selected from the combination of the said cationic component and anionic component. Examples of the ionic compound having an organic cation are classified for each structure of the organic cation and shown below.

Pyridinium Salts:

 N-hexylpyridinium hexafluorophosphate,

N-octylpyridinium hexafluorophosphate,

N-octyl-4-methylpyridinium hexafluorophosphate,

N-butyl-4-methylpyridinium hexafluorophosphate,

N-decylpyridinium bis (fluorosulfonyl) imide,

N-dodecylpyridinium bis (fluorosulfonyl) imide,

N-tetradecylpyridinium bis (fluorosulfonyl) imide,

N-hexadecylpyridinium bis (fluorosulfonyl) imide,

N-dodecyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-tetradecyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-hexadecyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-benzyl-2-methylpyridinium bis (fluorosulfonyl) imide,

N-benzyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-hexylpyridinium bis (trifluoromethanesulfonyl) imide,

N-octylpyridinium bis (trifluoromethanesulfonyl) imide,

N-octyl-4-methylpyridinium bis (trifluoromethanesulfonyl) imide,

N-butyl-4-methylpyridinium bis (trifluoromethanesulfonyl) imide.

Imidazolium Salt:

1-ethyl-3-methylimidazolium hexafluorophosphate,

1-ethyl-3-methylimidazolium p-toluenesulfonate,

1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide,

1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide,

1-butyl-3-methylimidazolium methanesulfonate,

1-butyl-3-methylimidazolium bis (fluorosulfonyl) imide.

Pyrrolidinium Salts:

N-butyl-N-methylpyrrolidinium hexafluorophosphate,

N-butyl-N-methylpyrrolidinium bis (fluorosulfonyl) imide,

N-butyl-N-methylpyrrolidinium bis (trifluoromethanesulfonyl) imide.

Quaternary Ammonium Salts:

Tetrabutylammonium hexafluorophosphate,

Tetrabutylammonium p-toluenesulfonate,

(2-hydroxyethyl) trimethylammonium bis (trifluoromethanesulfonyl) imide,

(2-hydroxyethyl) trimethylammonium dimethylphosphinate.

Examples of the ionic compound having an inorganic cation are shown below.

Lithium bromide,

Lithium iodide,

Lithium tetrafluoroborate,

Lithium hexafluorophosphate,

Lithium thiocyanate,

Lithium perchlorate,

Lithium trifluoromethanesulfonate,

Lithium bis (fluorosulfonyl) imide,

Lithium bis (trifluoromethanesulfonyl) imide,

Lithium bis (pentafluoroethanesulfonyl) imide,

Lithium tris (trifluoromethanesulfonyl) methanide,

Lithium p-toluenesulfonate,

Sodium hexafluorophosphate,

Sodium bis (fluorosulfonyl) imide,

Sodium bis (trifluoromethanesulfonyl) imide,

Sodium p-toluenesulfonate,

Potassium hexafluorophosphate,

Potassium bis (fluorosulfonyl) imide,

Potassium bis (trifluoromethanesulfonyl) imide,

Potassium p-toluenesulfonate.

It is preferable that an ionic compound is solid at room temperature. According to the ionic compound which is solid at room temperature, the antistatic performance can be maintained for a long time compared with the case of using the liquid ionic compound at room temperature. From the viewpoint of the long-term stability of the antistatic property, the ionic compound preferably has a melting point of 30 ° C or higher, more preferably 35 ° C or higher. On the other hand, if the melting point is too high, the compatibility with the (meth) acrylic resin deteriorates, so that the melting point of the ionic compound is preferably 90 ° C. or less, more preferably 70 ° C. or less, still more preferably 50 Less than 캜.

Content of the ionic compound in an adhesive composition becomes like this. Preferably it is 0.2 mass part or more and 8 mass parts or less, More preferably, it is 0.2 mass part or more and 6 mass parts or less, More preferably, with respect to 100 mass parts of (meth) acrylic-type resins. Preferably it is 0.5 mass part or more and 5 mass parts or less, Especially preferably, they are 1 mass part or more and 5 mass parts or less. The content of the ionic compound of 0.2 parts by mass or more is advantageous for the improvement of the antistatic performance, and the content of 8 parts by mass or less is advantageous for maintaining the heat resistance and durability of the pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer 20).

[3-4] Silane Compound

The pressure-sensitive adhesive composition may further contain a silane compound. Thereby, adhesiveness of an adhesive layer (1st adhesive layer 20) and optical members, such as a glass substrate, can be improved.

Examples of the silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyl Trimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethylsilane and the like Can be mentioned.

You may use 2 or more types of silane compounds.

The silane compound may be a silicone oligomer type. When a silicone oligomer is represented by the form of a (monomer) oligomer, the following are mentioned, for example.

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer,

3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer,

3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer,

3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer

Mercaptopropyl group-containing copolymers such as these;

Mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer,

Mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer,

Mercaptomethyltriethoxysilane-tetramethoxysilane copolymer,

Mercaptomethyltriethoxysilane-tetraethoxysilane copolymer

Mercaptomethyl group-containing copolymers such as these;

3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer,

3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer,

3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer,

3-glycidoxypropyltriethoxysilane-tetraethoxysilane copolymer,

3-glycidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,

3-glycidoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,

3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,

3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer

Copolymers containing 3-glycidoxypropyl groups such as these;

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,

3-Methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer

Copolymers containing methacryloyloxypropyl groups such as these;

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,

3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer

Acryloyloxypropyl group containing copolymers, such as these;

Vinyltrimethoxysilane-tetramethoxysilane copolymer,

Vinyltrimethoxysilane-tetraethoxysilane copolymer,

Vinyltriethoxysilane-tetramethoxysilane copolymer,

Vinyltriethoxysilane-tetraethoxysilane copolymer,

Vinylmethyldimethoxysilane-tetramethoxysilane copolymer,

Vinylmethyldimethoxysilane-tetraethoxysilane copolymer,

Vinylmethyldiethoxysilane-tetramethoxysilane copolymer,

Vinylmethyldiethoxysilane-tetraethoxysilane copolymer

Vinyl group-containing copolymers such as these;

3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer,

3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer,

3-aminopropyltriethoxysilane-tetramethoxysilane copolymer,

3-aminopropyltriethoxysilane-tetraethoxysilane copolymer,

3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer,

3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer,

3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer,

3-Aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer

Amino-group-containing copolymers, such as these.

Most of the silane compounds exemplified above are liquids. Content of the silane compound in an adhesive composition is 0.01 mass part or more and 10 mass parts or less normally with respect to 100 mass parts of (meth) acrylic-type resins, Preferably it is 0.05 mass part or more and 5 mass parts or less, More preferably, it is 0.2 mass part 0.4 parts by mass or more. When content of a silane compound is 0.01 mass part or more, the adhesive improvement effect of an adhesive layer (1st adhesive layer 20) and optical members, such as a glass substrate, is easy to be obtained. Moreover, if content of a silane compound is 10 mass parts or less, the bleed out of the silane compound from an adhesive layer can be suppressed.

[3-5] Other Ingredients

The pressure-sensitive adhesive composition may contain additives such as crosslinking catalysts, weather stabilizers, tackifiers, plasticizers, softeners, dyes, pigments, inorganic fillers, light scattering fine particles, and resins other than (meth) acrylic resins. In addition, an ultraviolet curable compound is mix | blended with an adhesive composition, after forming an adhesive layer, it can also irradiate and harden an ultraviolet-ray, and can also be set as a harder adhesive layer.

As a crosslinking catalyst, for example, amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin and melamine resin Can be mentioned.

[3-6] Gel fraction of the pressure-sensitive adhesive layer

In the polarizing plate with a pressure-sensitive adhesive layer according to the present invention, the pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer 20) is a gel after heating at 80 ° C. for 24 hours from the viewpoint of achieving both good deflection and good heat resistance of the laminated optical member. Fraction (hereinafter may be referred to as "G80"). Gel fraction at (%) and 23 ° C (hereinafter, may be referred to as "G23".) The absolute value of the difference of [%] is more than 5 points. Big.

The absolute value of the difference between G80 [%] and G23 [%] is particularly preferably 10 points or more, more preferably 15 points or more, still more preferably 20 points or more, and 50 points from the viewpoint of improving the warpage resistance. It is especially preferable that it is above.

In order to improve the curvature resistance of the laminated optical member, the heat resistance durability of the laminated optical member, and the adhesiveness between the pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer 20) and other optical members in the laminated optical member, It is preferable to satisfy any one or more of A) and (B).

(A) G23 is 80% or less.

(B) G80 is 60% or more.

From the viewpoint of the warpage resistance of the laminated optical member, G80 is preferably 60% or more, more preferably 65% or more, still more preferably 70% or more, further preferably 95% or less, and more preferably It is 90% or less, More preferably, it is 88% or less.

In addition, from the viewpoint of the warpage resistance of the laminated optical member, G23 is preferably 80% or less. The lower limit of G23 is not particularly limited, but is preferably 5% or more.

In general, G80 is larger than G23. G23 and G80 are measured according to the method as described in the term of the [Example] mentioned later.

For example, it exists in the tendency which G23 can be made small by not containing a crosslinking agent in the adhesive composition which forms an adhesive layer, or reducing the content. Moreover, there exists a tendency which can make G23 small by reducing content of the polar functional group which can react with the crosslinking agent in the (meth) acrylic resin contained in an adhesive composition.

Moreover, the adhesive composition is a structural unit derived from the (meth) acrylic-type monomer which has a carboxyl group, and the structural unit derived from the alkoxyalkyl (meth) acrylamide monomer like the alkoxyalkyl (meth) acrylamide monomer represented by said Formula (III). Including (meth) acrylic-type resin containing is advantageous in raising G80.

From a viewpoint of raising G80, the said (meth) acrylic-type resin is a structural unit derived from the (meth) acrylic acid ester represented by said Formula (I), the structural unit derived from the (meth) acrylic-type monomer which has a hydroxyl group, and a carboxyl group The structural unit derived from the (meth) acrylic monomer which has, the structural unit derived from the phenoxyethyl group containing (meth) acrylic acid ester represented by said Formula (II), and the alkoxyalkyl (meth) acrylamide represented by said Formula (III) It is preferable to include the structural unit derived from the alkoxyalkyl (meth) acrylamide monomer like a monomer.

[3-7] Formation of pressure-sensitive adhesive layer

An adhesive layer (1st adhesive layer 20) melt | dissolves or disperse | distributes each component which comprises the said adhesive composition in a solvent, it is set as the adhesive composition containing a solvent, and then apply | coated on the base film or the polarizing plate 10, It can obtain by drying.

It is common that a base film is a thermoplastic resin film, and the typical film to which the mold release process was performed is mentioned as a typical example. The separator film may be one in which a release treatment such as silicone treatment is performed on a surface on which a pressure-sensitive adhesive layer of a film made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate is formed.

For example, a pressure-sensitive adhesive layer is formed by directly applying a pressure-sensitive adhesive composition to a release treatment surface of a separate film, and a pressure-sensitive adhesive layer with a pressure-sensitive adhesive layer can be obtained by laminating the pressure-sensitive adhesive layer with a separate film on the polarizing plate 10.

The pressure-sensitive adhesive composition may be directly applied to the surface of the polarizing plate 10 to form a pressure-sensitive adhesive layer. If necessary, a separator film may be laminated on the outer surface of the pressure-sensitive adhesive layer to form a polarizing plate with a pressure-sensitive adhesive layer.

When forming an adhesive layer on the surface of the polarizing plate 10, it is preferable to perform surface activation treatment, such as a plasma treatment, a corona treatment, etc. to the bonding surface of the polarizing plate 10 and / or the bonding surface of an adhesive layer, and it is a corona treatment. It is more preferable to carry out.

The thickness of the pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer 20) is preferably 10 µm or more and 45 µm or less, more preferably 10 µm or more and 30 µm or less, still more preferably 10 µm or more and 25 µm or less. The thickness of the pressure-sensitive adhesive layer in this range can be advantageous in increasing the warpage resistance and heat resistance of the laminated optical member, and / or the adhesiveness between the pressure-sensitive adhesive layer in the laminated optical member and other optical members.

<Laminated optical member>

As shown in FIGS. 1-4, the laminated optical member is a laminated body of the optical member 30 other than the polarizing plate 25 with an adhesive layer, and the polarizing plate 25 with an adhesive layer. Usually, the laminated optical member includes the optical member 30 and the polarizing plate 25 with an adhesive layer laminated | stacked on it through the 1st adhesive layer 20 on it.

According to the polarizing plate 25 with an adhesive layer which concerns on this invention, it is possible to provide the laminated optical member with favorable curvature resistance and heat resistance durability.

As the optical member 30, image display elements, such as a liquid crystal cell and an organic electroluminescent display element, are mentioned.

The optical member 30 may be a member constituting the image display element, for example, a substrate.

As a board | substrate, a thermoplastic resin film, a glass substrate, etc. are mentioned.

Example

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further more concretely, this invention is not limited by these examples. Hereinafter, the part and% which show usage amount-content are a mass reference | standard unless there is particular notice.

<Manufacture example 1-9: Production of (meth) acrylic-type resin for adhesive layers>

Into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer, a monomer mixture (mass% when the total amount of monomers was 100 mass%) shown in Table 1 was added thereto, and a monomer mixture diluted with ethyl acetate was added thereto. The internal temperature was raised to 55 ° C. while replacing the air in the apparatus with nitrogen gas to make oxygen free. Then, the whole amount of the solution which melt | dissolved azobisisobutyronitrile (polymerization initiator) in ethyl acetate was added. After the polymerization initiator was added, the mixture was kept at this temperature for 1 hour, and then ethyl acetate was continuously added to the reaction vessel while maintaining the internal temperature at 54 to 56 ° C, and the concentration of the (meth) acrylic resin was 35% by mass. At the time point, the addition of ethyl acetate was stopped, and the resultant was kept at this temperature until 12 hours had elapsed from the start of addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the (meth) acrylic resin to 20% by mass to prepare an ethyl acetate solution of the (meth) acrylic resin.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of obtained (meth) acrylic-type resin were measured.

Mw and Mn are four "TSKgel XL" manufactured by Toso Corporation, and "Shodex GPC KF-802" sold by Shoko Tsusho Co., Ltd., as a column in a GPC device. A total of five ones are connected in series, and tetrahydrofuran is used as an eluent, and standard polystyrene conversion is performed under conditions of a sample concentration of 5 mg / mL, a sample introduction amount of 100 μL, a temperature of 40 ° C., and a flow rate of 1 mL / min. Measured by

The monomer composition (mass%) of the used monomer mixture and Mw and molecular weight distribution (Mw / Mn) of the obtained (meth) acrylic-type resin were put together in Table 1.

The abbreviation in the column of "monomer composition" of Table 1 means the next monomer.

BA: Butyl acrylate

MA: Methyl acrylate

PEA: 2-phenoxyethyl acrylate

PEA2: 2- (2-phenoxyethoxy) ethyl acrylate

HEA: 2-hydroxyethyl acrylate

BMAA: N-butoxymethylacrylamide

MEA: methoxyethyl acrylate

AA: acrylic acid

<Examples 1-9, Comparative Examples 1-2>

(1) Preparation of pressure-sensitive adhesive composition

With respect to 100 mass parts of solid content of (meth) acrylic-type resin obtained by the said manufacturing example, the amount (mass part) of a crosslinking agent and a silane compound shown in Table 2 are mixed (the example which does not mix a crosslinking agent), and solid content concentration is 28 mass parts Ethyl acetate was added to make%, to prepare a solution of the pressure-sensitive adhesive composition. In Table 2, the compounding quantity (mass part) of a crosslinking agent and a silane compound is solid content conversion amount.

The crosslinking agent used in the Example and the comparative example is all "Colonate L" (The ethyl acetate solution of the trimethylolpropane adduct of tolylene diisocyanate: solid content concentration 75 mass%) obtained from Toso Corporation. In addition, the silane compounds used in the Example and the comparative example are all "KBM-403" (3-glycidoxypropyl trimethoxysilane) obtained from Shin-Etsu Chemical Co., Ltd ..

(2) Preparation of pressure-sensitive adhesive layer and measurement of gel fraction

The thickness after drying using the applicator to the release process surface of the separator film ("PLR-382190" obtained from Lintec Co., Ltd.) which consists of the polyethylene terephthalate film to which the mold release process was performed for the adhesive composition prepared by said (1). Was applied so as to be 20 µm, and dried at 100 ° C. for 1 minute to produce an adhesive layer (adhesive sheet).

About the adhesive layer (adhesive sheet) which was left to stand at 23 degreeC for 5 days from immediately after obtained, the gel fraction (gel fraction in 23 degreeC (G23)) was measured. The gel fraction was measured according to the following [a]-[d]. The results are shown in Table 3.

[A] A pressure-sensitive adhesive layer having an area of about 8 cm × about 8 cm and a metal mesh made of SUS304 of about 10 cm × about 10 cm (the mass is Wm) are joined.

[B] The joined product obtained in the above [a] is weighed, its mass is Ws, and then folded four times so as to surround the pressure-sensitive adhesive layer and fixed with a stapler (stapler), followed by weighing, and the mass is Wb.

(C) The mesh fixed by the stapler in [b] is put into a glass container, 60 mL of ethyl acetate is added and immersed, and this glass container is stored at room temperature for 3 days.

[D] The mesh was taken out from the glass container, dried at 120 ° C. for 4 hours, weighed, and the mass thereof was Wa, and the following formula:

Gel fraction (mass%) = [{Wa- (Wb-Ws) -Wm} / (Ws-Wm)] x100 The gel fraction is calculated.

After leaving for 5 days at 23 ° C. immediately after obtained, the gel fraction [heated at 80 ° C. for 24 hours, in the same manner as above, except that the pressure-sensitive adhesive layer (adhesive sheet) was left for 24 hours in a dry atmosphere at 80 ° C. Gel fraction (G80)] was measured. The results are shown in Table 3. Table 3 also shows the difference between G80 and G23 (G80-G23).

(3) Preparation of polarizing plate and measurement of maximum curl force in 80 degreeC

A protective film having a thickness of 75 µm made of (meth) acrylic resin on one side of a polarizer having a thickness of 23 µm with iodine adsorbed on a uniaxially stretched polyvinyl alcohol film, and having a thickness of 50 µm having a cyclic polyolefin resin on the other side. The polarizing plate was produced by bonding retardation film through the active energy ray curable adhesive agent.

About the obtained polarizing plate, the largest curling force in 80 degreeC was measured according to the following procedure.

The sample of size 40 mm x 40 mm was cut out from the polarizing plate so that a pair of opposing sides may be parallel to the absorption axis of a polarizer. The sample was placed on the main body plate of a viscoelasticity measuring apparatus ("Physica MCR301" manufactured by Anton Paar, Inc.) so that the retardation film side turned up, and the measurement jig (PP25) was arrange | positioned at the center part. The gap of a measuring jig was adjusted so that the stress applied to the measuring jig might be about 3 N, and the position which raised 0.02 mm from it was made into reference height.

Subsequently, the body plate was heated up from 23 ° C to 80 ° C at 2 ° C / min, and maintained at 240 ° C at 80 ° C, while monitoring the stress applied to the measuring jig, and then lowered to 23 ° C at 2 ° C / min. The maximum value of the stress applied to the measuring jig according to the heating shrinkage of the sample recorded at this time was taken as the maximum curl force [mN] at 80 ° C. The maximum curling force at 80 ° C. was 1716 mN.

(4) Preparation of polarizing plate with pressure sensitive adhesive layer

After bonding the surface (adhesive layer surface) on the opposite side to the separator film in the adhesive layer produced by said (2) to the outer surface of the retardation film of a polarizing plate with a laminator, on condition of temperature of 23 degreeC and 65% of relative humidity. It cured for 5 days and obtained the polarizing plate with an adhesive layer.

(5) Evaluation of warpage resistance of the laminated optical member

The polarizing plate with an adhesive layer obtained by said (4) was cut out to size 150 mm x 40 mm so that the absorption axis of a polarizer might become a long side. The separator film is peeled off from the cut polarizing plate with the pressure-sensitive adhesive layer, and the exposed pressure-sensitive adhesive layer is bonded to a central portion of an alkali-free glass substrate (“Eagle XG” manufactured by Corning Corporation) having a length of 160 mm, a width of 50 mm, and a thickness of 0.5 mm. This was made into a sample. This sample was left to stand for 24 hours in 80 degreeC dry atmosphere. Thereafter, the sample was taken out under an environment of a temperature of 23 ° C. and a relative humidity of 55%, and the sample was obtained by using a two-dimensional dimensional measuring device (“NEXIV model number: VMZ-R4540 manufactured by Nikon Corporation”) within 30 minutes after taking out. The difference of the height from the base of a polarizing plate center part and each edge (four points) of polarizing plates was measured. The average value of the obtained four values was made into the curvature amount [mm] of the said sample. The results are shown in Table 3. If the amount of warpage is 2.0 mm or less, the warpage resistance can be evaluated as good.

(6) Heat resistance durability evaluation of laminated optical member

(6-1) Lifting, peeling and foaming at the interface

After peeling a separator from the polarizing plate with an adhesive layer produced by said (4), the adhesive layer surface was adhere | attached on both surfaces of an alkali-free glass substrate ("Eagle XG" by a Corning company), and the sample for evaluation was produced. . Using this sample, the following two types of heat resistance tests were performed.

[Heat resistance durability test]

Heat resistance test maintained for 500 hours under drying conditions at a temperature of 80 ° C

Heat shock (HS) resistance test which keeps for 30 minutes under the drying conditions of 70 degreeC temperature, and keeps 30 minutes under the dry conditions of temperature -40 degreeC as 1 cycle, and repeats this for 200 cycles.

About the sample after each test, the presence or absence of lifting and peeling at the interface of an adhesive layer and a glass substrate, and the foaming of an adhesive layer were observed visually, and the heat resistance durability was evaluated according to the following evaluation criteria. The results are shown in Table 3 (heat resistance X in Table 3).

A: No change in appearance such as lifting, peeling or foaming is observed.

B: A slight change in appearance such as lifting, peeling and foaming is observed.

C: Changes in appearance such as lifting, peeling and foaming are large.

(6-2) presence or absence of foaming at an interface end

After peeling a separator from the polarizing plate with an adhesive layer produced by said (4), the adhesive layer surface was adhere | attached on both surfaces of an alkali-free glass substrate ("Eagle XG" by a Corning company), and the sample for evaluation was produced. . Using this sample, the following two types of heat resistance tests were performed.

[Heat resistance durability test]

Heat resistance test maintained for 500 hours under drying conditions at a temperature of 80 ° C

Heat shock (HS) resistance test which keeps for 30 minutes under the drying conditions of 70 degreeC temperature, and keeps 30 minutes under the dry conditions of temperature -40 degreeC as 1 cycle, and repeats this for 200 cycles.

About the sample after each test, the presence or absence of the stripe foam which generate | occur | produces in the edge part of the interface of the adhesive layer and the glass substrate of an evaluation sample edge part was observed visually, and the heat resistance durability was evaluated according to the following evaluation criteria. The results are shown in Table 3 (heat resistance durability Y in Table 3).

A: Striped foaming is not seen

B: Stripe foaming is seen slightly

C: Striped foaming is seen large

(7) Evaluation of adhesiveness in laminated optical member

The polarizing plate with an adhesive layer obtained by said (4) was cut out to size 150 mm x 25 mm so that the absorption axis of a polarizer might become a long side. The separator film is peeled off from the cut polarizing plate with the pressure-sensitive adhesive layer, and the exposed pressure-sensitive adhesive layer is bonded to a central portion of an alkali-free glass substrate (“Eagle XG” manufactured by Corning Corporation) having a length of 160 mm, a width of 50 mm, and a thickness of 0.7 mm. The test piece (the polarizing plate with an adhesive layer with which the glass substrate was adhere | attached) which the obtained glass substrate adhere | attached was then pressurized for 20 minutes at the temperature of 50 degreeC, and the pressure of 5 kgf / cm <2> (490.3 kPa) in an autoclave, and this was made into the sample. . Then, it stored for 24 hours in the environment of the temperature of 23 degreeC, and 55% of a relative humidity.

Subsequently, a blade of a cutter is inserted between the glass substrate and the pressure-sensitive adhesive layer, and 30 mm is peeled off from the end in the longitudinal direction, and the peeled portion is subjected to a universal tensile tester (manufactured by Shimadzu Seisakusho Co., Ltd. 50NX ”]. Grip movement speed 300 mm / according to JIS K 6854-2: 1999 "Adhesive-peeling adhesive strength test method-Part 2: 180 degree peeling" in the test piece of this state in the atmosphere of 55% of temperature 23 degreeC relative humidity. 180 degree peel test was done in minutes. The average peeling force over the length of 120 mm except 30 mm of a grip part was calculated | required, and this was made into the adhesive force in the temperature of 23 degreeC. The results are shown in Table 3.

In addition, the adhesive force was measured in the same manner as above except that the sample was allowed to stand for 48 hours in a 50 ° C dry atmosphere, and the sample was measured in an atmosphere having a temperature of 23 ° C and a relative humidity of 55%. It was set as the adhesive force in. The results are shown in Table 3.

1: polarizer 2: surface treatment layer
3: 1st protective film 4: 2nd protective film
7: retardation film 8: 2nd adhesive layer
10: polarizing plate 20: first pressure sensitive adhesive layer
25: polarizing plate with pressure-sensitive adhesive layer 30: optical member

Claims (7)

The polarizing plate whose maximum curling force in 80 degreeC is 500 mN or more,
Pressure-sensitive adhesive layer laminated on the polarizing plate
Including,
The said adhesive layer is a polarizing plate with an adhesive layer whose absolute value of the difference of the gel fraction (G80) [%] and the gel fraction (G23) [%] at 23 degreeC after heating at 80 degreeC for 24 hours is larger than 5 points. The said adhesive layer is a polarizing plate with an adhesive layer of Claim 1 whose gel fraction (G80) after heating at 80 degreeC for 24 hours is 60% or more. The said adhesive layer is a polarizing plate with an adhesive layer of Claim 1 or 2 whose gel fraction (G80) after heating at 80 degreeC for 24 hours is 95% or less. The polarizing plate with a pressure-sensitive adhesive layer according to any one of claims 1 to 3, wherein the polarizing plate comprises a polarizer having a thickness of 10 µm or more. The polarizing plate with an adhesive layer of any one of Claims 1-4 in which the said adhesive layer is formed from the adhesive composition containing (meth) acrylic-type resin. The said (meth) acrylic-type resin is a polarizing plate with an adhesive layer of Claim 5 containing the structural unit derived from the (meth) acrylic-type monomer which has a carboxyl group, and the structural unit derived from the alkoxyalkyl (meth) acrylamide monomer. The said adhesive composition is a polarizing plate with an adhesive layer of Claim 5 or 6 whose content of a crosslinking agent is 0 mass part or more and 2 mass parts or less with respect to 100 mass parts of (meth) acrylic-type resins.

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