JPH0922007A - Adhesive composition for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compsn. to be used to adhere a liquid crystal cell to a polarizing plate of a liquid crystal display device for the purpose of display which uses responsiveness of liquid crystal molecules to an electric field. SOLUTION: This thermosetting adhesive essentially consists of at least one kind of polymer selected from a group of ionomer resins produced by coupling metal ions among molecules of ethylenevinyl acetate copolymer, copolymer of ethylene, vinyl acetate and acrylate and/or methacrylate monomers, copolymer of ethylene, vinyl acetate and maleic acid and/or maleic acid anhydride, copolymer of ethylene, acrylate and/or methacrylate monomers and maleic acid and/or maleic acid anhydride, and ethylene-methacrylate copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition used in the field of optoelectronics for bonding a liquid crystal cell and a polarizing plate of a liquid crystal display device for the purpose of display utilizing the response of liquid crystal molecules by an electric field. Regarding things.

[0002]

2. Description of the Related Art Conventionally, the alignment layers of two substrates having a transparent electrode and an alignment layer formed on one surface thereof are opposed to each other, and a liquid crystal layer is interposed therebetween, and A liquid crystal display (LCD) having a polarizing plate bonded to the other surface of the substrate is widely used. In this case, a technique of using an acrylic pressure-sensitive adhesive for bonding the substrate and the polarizing plate is known (Japanese Patent Laid-Open No. 57-1952).
08, JP-A-3-12471).

Here, the polarizing plate for a liquid crystal display device is one in which both sides of a polarizing film are covered and protected by protective films. The protective film is a cellulose film,
Polyester resin film, polyacrylic resin film, polycarbonate film, polyether sulfone, etc. are used, while glass, polycarbonate, polyester resin, polyarylate resin, etc. are also becoming a wide variety of surface substrates for liquid crystal cells. In addition, after bonding the both, durability is required for various treatments and practical use. However, in the current acrylic pressure-sensitive adhesive, the adhesive strength depends on the bonding pressure, and the heat resistance after bonding,
There is an undeniable decrease in adhesive strength due to the accelerated heat and humidity resistance test, and peeling, floating and foaming occur at the adhesive interface. In other words, when heat treatment such as transparent electrode formation and alignment treatment is applied to the substrate surface of the laminated body in which the polarizing plate and the surface substrate of the liquid crystal cell are adhered and integrated, the heat resistance of the conventional acrylic pressure-sensitive adhesive is high. Therefore, there is a problem that peeling of the adhesive interface occurs due to the low value.

The present invention has been made in view of the above circumstances, and since it has excellent initial adhesive strength and excellent heat resistance, it can sufficiently withstand heat treatment and is excellent in durability, and has excellent durability and polarization. An object is to provide an adhesive composition for a liquid crystal display device, which is used for adhesion to a plate.

[0005]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of intensive studies to achieve the above object, the present inventors have found that ethylene-vinyl acetate is used for adhesion between the substrate of the liquid crystal cell and the polarizing plate. Copolymers, copolymers of ethylene with vinyl acetate and acrylate and / or methacrylate monomers, copolymers of ethylene with vinyl acetate, maleic acid and / or maleic anhydride, ethylene with acrylates and / or methacrylates Main component is at least one polymer selected from the group consisting of a copolymer of a system monomer and maleic acid and / or maleic anhydride, and an ionomer resin in which ethylene-methacrylic acid copolymer has intermolecular bonds with metal ions. When a thermosetting adhesive is used, this adhesive is a thermosetting polymer whose main component is a polymer with excellent transparency and weather resistance. Since it is an adhesive, it has a high initial adhesive strength and can be bonded to a polarizing plate with excellent durability, and since this adhesive has excellent heat resistance, it can withstand heat treatment. The present inventors have found that it is possible to provide a polarizing plate in which a surface substrate of a liquid crystal cell is also integrated, and have completed the present invention.

Therefore, the present invention manufactures a liquid crystal display device including a liquid crystal cell in which a liquid crystal layer is provided on one surface of a substrate through a transparent electrode and an alignment layer, and a polarizing plate adhered to the other surface of the substrate. In this case, in the adhesive composition used for adhering the substrate and the polarizing plate, the adhesive composition is an ethylene-vinyl acetate copolymer, or a copolymer of ethylene, vinyl acetate and an acrylate-based and / or methacrylate-based monomer. A copolymer of ethylene with vinyl acetate and maleic acid and / or maleic anhydride; a copolymer of ethylene with an acrylate and / or methacrylate monomer and maleic acid and / or maleic anhydride; ethylene-methacrylic acid copolymer The main component is at least one polymer selected from the group consisting of ionomer resins in which the molecules of the polymer are bound by metal ions. To provide a liquid crystal display device adhesive composition which is a thermosetting adhesive.

Hereinafter, the present invention will be described in more detail. The adhesive composition according to the present invention comprises an ethylene-vinyl acetate copolymer as a main component, an ethylene / vinyl acetate / acrylate and / or methacrylate monomer copolymer. A copolymer of ethylene with vinyl acetate and maleic acid and / or maleic anhydride; a copolymer of ethylene with an acrylate and / or methacrylate monomer and maleic acid and / or maleic anhydride; ethylene-methacrylic acid copolymer The thermosetting adhesive is characterized by using at least one polymer selected from the group consisting of ionomer resins in which the molecules of the polymer are bound by metal ions.

When an ethylene-vinyl acetate copolymer is used as the polymer, the ethylene-vinyl acetate copolymer preferably has a vinyl acetate content of 10 to 50% by weight, more preferably 14 to 45% by weight. %.
When the vinyl acetate content is lower than 10% by weight, the transparency and optical uniformity of the heat-cured adhesive will not be sufficient, while when it exceeds 50% by weight, the transparency and optical uniformity will be good. The strength and durability of the adhesive layer tend to be significantly reduced.

Further, the copolymer comprising ethylene, vinyl acetate, and an acrylate-based and / or methacrylate-based monomer preferably has a vinyl acetate content of 1 or less.
0 to 50% by weight, more preferably 14 to 45% by weight is used. When the vinyl acetate content is lower than 10% by weight, the transparency and optical uniformity of the heat-cured adhesive will not be sufficient, while when it exceeds 50% by weight, the transparency and optical uniformity will be good. The strength and durability of the adhesive layer tend to be significantly reduced. Furthermore, the content of the acrylate-based and / or methacrylate-based monomer is 0.
It is preferably from 01 to 10% by weight, more preferably from 0.05 to 5% by weight. When the content of the monomer is less than 0.01% by weight, the effect of improving the adhesive strength is lowered, while when it exceeds 10% by weight, the processability may be lowered.

The acrylate-based and / or methacrylate-based monomers that can be used are monomers selected from acrylic acid ester or methacrylic acid ester-based monomers. Acrylic acid or methacrylic acid and 1 to 20 carbon atoms, particularly 1 to Ester with 18 unsubstituted or substituted aliphatic alcohols having a substituent such as an epoxy group is preferable, and examples thereof include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, and glycidyl methacrylate.

Further, the copolymer of ethylene, vinyl acetate, maleic acid and / or maleic anhydride preferably has a vinyl acetate content of 10 to 50% by weight, more preferably 14 to 45% by weight. Stuff used. When the vinyl acetate content is lower than 10% by weight, the transparency and optical uniformity of the heat-cured adhesive will not be sufficient, while when it exceeds 50% by weight, the transparency and optical uniformity will be good. The strength and durability of the adhesive layer tend to be significantly reduced. The content of maleic acid and / or maleic anhydride is preferably 0.01 to 10% by weight, more preferably 0.05 to 5% by weight. If the content is less than 0.01% by weight, the effect of improving the adhesive strength is reduced, while if it exceeds 10% by weight, the processability may be reduced.

The copolymer of ethylene, an acrylate and / or methacrylate monomer and maleic acid and / or maleic anhydride preferably has an acrylate compound content of 10 to 50% by weight, more preferably. 14 to 45% by weight is used. When the content of the acrylate compound is lower than 10% by weight, the transparency and optical uniformity of the heat-cured adhesive will not be sufficient, while when it exceeds 50% by weight, the transparency and optical uniformity will be good. However, the strength and durability of the adhesive layer tend to be significantly reduced. Further, the content of maleic acid and / or maleic anhydride is preferably 0.01 to 10% by weight, more preferably 0.05 to 5% by weight. If the content is less than 0.01% by weight, the effect of improving the adhesive strength is reduced, while if it exceeds 10% by weight, the processability may be reduced.

As the acrylate-based and / or methacrylate-based monomers, the same ones as mentioned above can be mentioned.

Further, an ionomer resin in which the molecules of the ethylene-methacrylic acid copolymer are bonded with a metal ion (hereinafter referred to as an ethylene-methacrylic acid ionomer resin).
Is used, the methacrylic acid content of the ethylene-methacrylic acid ionomer resin is preferably 1 to 30% by weight, more preferably 5 to 25% by weight. If the methacrylic acid content is less than 1% by weight, the ionic crosslinking effect will be reduced, and the adhesive strength will be reduced.
If it exceeds the weight%, the workability may be significantly lowered.

The metal ions used for the ethylene-methacrylic acid ionomer resin are metal ions such as sodium, zinc, magnesium and lithium, and the ionization degree by the metal ions is preferably 5 to 80%. , And more preferably 7 to 70%. If the ionization degree is less than 5%, the transparency is significantly reduced, and 8
If it exceeds 0%, the workability may be significantly lowered.

An organic peroxide is added to the adhesive composition of the present invention for curing. As the organic peroxide to be added, any one can be used as long as it decomposes to generate a radical at a temperature of 70 ° C. or higher, but a decomposition temperature with a half-life of 10 hours is 50 ° C. or higher is more preferable. It can be selected in consideration of film forming processing temperature, crosslinking temperature, storage stability and the like.

Examples of usable peroxides are 2,
5-Dimethylhexane-2,5-dihydroperoxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3; di-t-butylperoxide; t-butylcumylperoxide 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; dicumyl peroxide; α, α′-bis (t-butylperoxyisopropyl) benzene; n-butyl-4,4
-Bis (t-butylperoxy) valerate; 2,2-
Bis (t-butylperoxy) butane; 1,1-bis (t-butylperoxy) cyclohexane; 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane; t-butylper Oxybenzoate;
Benzoyl peroxide; t-butyl peroxyacetate; 1,1-bis (t-butylperoxy) -3,
3,5-trimethylcyclohexane; 1,1-bis (t
-Butyloxy) cyclohexane; methyl ethyl ketone peroxide; t-butyl hydroperoxide; p-menthane hydroperoxide; hydroxyheptyl peroxide; chlorhexanone peroxide; octanoyl peroxide; decanoyl peroxide; lauroyl peroxide; kumi Ruperoxy Octoate; Succinic Acid Peroxide; Acetyl Peroxide; t-Butyl Peroxy (2-ethylhexanoate); m-Toluoyl Peroxide; Benzoyl Peroxide; t-Butyl Peroxy Isobutyrate; 2 , 4-dichlorobenzoyl peroxide and the like.

As the organic peroxide, one of these is used.
Species can be used alone or as a mixture of two or more,
The amount added is usually 0.1 to 100 parts by weight of the polymer.
Ten parts by weight are sufficient.

A silane coupling agent may be added as an adhesion promoter to the adhesive composition of the present invention. Examples of the silane coupling agent include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy. Propyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (Aminoethyl) -γ-
There are aminopropyltrimethoxysilane and the like, and one of these may be used alone or two or more of them may be used in combination. The addition amount of these silane coupling agents is usually 0.01 to 5 parts by weight per 100 parts by weight of the polymer.

Further, in order to improve and adjust the physical properties (mechanical strength, optical properties, adhesiveness, heat resistance, moist heat resistance, weather resistance, crosslinking rate) of the adhesive composition of the present invention, etc. The compound containing an acryloxy group, a methacryloxy group or an allyl group can be added.

Most commonly used compounds for this purpose are acrylic acid or methacrylic acid derivatives such as their esters and amides. In this case, as the ester residue, in addition to an alkyl group such as methyl, ethyl, dodecyl, stearyl, and lauryl, a cyclohexyl group, a tetrahydrofurfuryl group, an aminoethyl group,
-Hydroxyethyl group, 3-hydroxypropyl group, 3
-Chloro-2-hydroxypropyl group and the like. Esters of acrylic acid or methacrylic acid with polyfunctional alcohols such as ethylene glycol, triethylene glycol, polyethylene glycol, glycerin, trimethylolpropane, and pentaerythritol are also used. A typical amide is acrylamide. Examples of the allyl group-containing compound include triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, diallyl maleate, and the like. One kind or a mixture of two or more kinds thereof is used as a polymer 100% by weight. 0.1 to 50 parts by weight,
It is preferably used by adding 0.5 to 30 parts by weight. 5
If it exceeds 0 parts by weight, workability and film-forming property at the time of preparation of the adhesive may be deteriorated, and if it is less than 0.1 parts by weight, the effect of improving mechanical strength may be deteriorated.

A hydrocarbon resin may be added to the adhesive composition of the present invention for the purpose of improving workability and workability such as bonding. In this case, the hydrocarbon resin to be added may be either a natural resin or a synthetic resin. Rosin, rosin derivatives, and terpene resins are preferably used in the natural resin system. For rosin, gum-based resins, tall oil-based resins, and wood-based resins can be used. As rosin derivatives, rosin is hydrogenated, heterogeneous,
Polymerized, esterified, metal-chlorinated ones can be used. As the terpene-based resin, terpene-based resins such as α-pinene and β-pinene, as well as terpene phenol resins can be used. Also, dammar, corval, and shellac may be used as other natural resins. On the other hand, in the case of synthetic resins, petroleum resins, phenol resins, and xylene resins are preferably used. Petroleum resins include aliphatic petroleum resins, aromatic petroleum resins, alicyclic petroleum resins,
Copolymer petroleum resins, hydrogenated petroleum resins, pure monomer petroleum resins, and coumarone indene resins can be used. As the phenolic resin, an alkylphenol resin and a modified phenol resin can be used. As the xylene-based resin, a xylene resin or a modified xylene resin can be used.

The amount of the above-mentioned hydrocarbon resin added is appropriately selected, but it is preferably 1 to 200 parts by weight, more preferably 5 to 150 parts by weight, based on 100 parts by weight of the polymer.

In addition to the above additives, the adhesive composition of the present invention may contain a small amount of an ultraviolet absorber, an antiaging agent, a dye, a processing aid and the like. In some cases, additives such as silica gel, calcium carbonate, silicon copolymer fine particles and the like may be contained in a small amount.

In the adhesive composition of the present invention, the above polymer and the above additives are uniformly mixed and kneaded with an extruder, a roll or the like, and then a film forming method such as calendering, roll, T-die extrusion, inflation or the like. It can be used by forming a film into a predetermined shape. In film formation, embossing may be performed in order to prevent blocking and facilitate degassing during pressure bonding with a polarizing plate protective film or a liquid crystal cell.
Further, the above-mentioned polymer and the above-mentioned additive are uniformly dissolved in a solvent that does not have any influence on the protective film or the liquid crystal cell surface substrate, uniformly applied on the surface of the film, temporarily pressure-bonded, and then heat-bonded and cured. Can be made.

The adhesive composition of the present invention is used, for example, in a liquid crystal display device as shown in FIG. 1, that is, transparent electrodes 3, 3'on one surface.
A liquid crystal cell 1 in which two substrates 2 and 2'having alignment layers 4 and 4'are arranged so that the alignment layers 4 and 4'are opposed to each other, and a liquid crystal layer 5 is interposed between them; In the manufacture of the liquid crystal display device including the polarizing plate 6 laminated on the other surface of the substrate 2 and the analysis plate 7 laminated on the other surface of the other substrate 2 ', the substrates 2 and 2'and the polarizing plate 6 are used. It is used to bond and. In this case, the polarizing plate 6 is usually formed by covering and protecting both surfaces of the polarizing film 6'with protective films 6 "and 6" as shown in FIG. 6 ″ is bonded to the substrates 2 and 2 ′. After such adhesion, a liquid crystal display device can be manufactured by a conventional method such as forming a transparent electrode on the entire surface of the substrate and further performing an alignment treatment.

The type of the above substrate can be appropriately selected, and examples thereof include glass, polycarbonate, polyester resin,
Examples thereof include polyarylate resin and polyether sulfone resin. Further, as a protective film for a polarizing plate adhered to this substrate, a cellulose-based film, a polyester resin, a polyacrylic resin film, a polycarbonate film, a polyether sulfone is used. A phone or the like can be exemplified.

The curing conditions for the thermosetting adhesive of the present invention depend on the type of organic peroxide used, but 70 to 1
70 ° C, especially 70-150 ° C for 2-60 minutes, especially 5-3
Preferably, it is 0 minutes. In this case, the curing is preferably 0.01 to 50 kgf / cm ² , especially 0.1 to 20.
It is recommended to work under a pressure of kgf / cm ² .

[0029]

Since the adhesive composition according to the present invention is a thermosetting adhesive containing the above polymer as a main component, it is excellent in transparency and weather resistance. Further, since it has a cross-linking structure with an organic peroxide, and an acryloxy group-containing compound, a methacryloxy group-containing compound, and an allyl group-containing compound which are further added as necessary, heat resistance, moist heat resistance and transparency are improved. In addition, the addition of the silane coupling agent improves the adhesiveness associated with thermosetting, and provides the initial adhesive strength and the adhesive strength with excellent thermal stability. Due to these actions, reliability such as heat resistance is dramatically improved as compared with conventional acrylic pressure-sensitive adhesives. Along with this, a laminated body in which a polarizing plate and a liquid crystal cell surface substrate are bonded and integrated. When heat treatment such as transparent electrode formation and orientation treatment is performed on the substrate surface, the conventional acrylic adhesive has low heat resistance and thus peels off at the adhesive interface. By using the composition, it is possible to provide a polarizing plate in which a liquid crystal cell surface substrate that can withstand heat treatment is also integrated.

[0030]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Example 1] Benzoyl peroxide (NIPPER B, manufactured by NOF CORPORATION) based on 100 parts by weight of ethylene-vinyl acetate copolymer (EVA; manufactured by Tosoh Corporation, Ultracene 760, vinyl acetate content 42%). 2.0 parts by weight, 0.5 parts by weight of γ-methacryloxypropyltrimethoxysilane (KBM503 manufactured by Shin-Etsu Silicone Co., Ltd.),
Triallyl isocyanurate (manufactured by Nippon Kasei Co., TAI
C) 2.0 parts by weight were mixed to prepare a solution in which the resin concentration was uniformly dissolved in toluene so that the resin concentration became 20% by weight. Then, this solution was uniformly applied onto a triacetate film using a roll coater, and the dried film was degassed to a polycarbonate film at 0.5 kgf / cm.
^It pressure-bonded with the pressure of ² , and this was heated in a 100 degreeC oven for 30 minutes, and the laminated body A was obtained.

Example 2 A laminate B using glass in place of the polycarbonate film in Example 1 was obtained by the same method.

[Example 3] A laminate C using a polyester film in place of the triacetate film and glass in place of the polycarbonate film in Example 1 was obtained by the same method.

Comparative Example A mixture of 95 parts by weight of ethyl acrylate and 5 parts by weight of acrylic acid was polymerized in toluene,
To this, 1 part by weight of polyisocyanate was added to obtain an acrylic pressure-sensitive adhesive. This was applied onto a triacetate film using a roll coater, dried, and pressure-bonded to a polycarbonate film under a pressure of 0.5 kgf / cm ² while degassing, to obtain a laminate D.

Next, a 180 ° peel test was conducted on the laminates of Examples 1 to 3 and Comparative Example under different temperature conditions.
The results are shown in Table 1.

[0036]

[Table 1]

Example 4 Benzoyl peroxide based on 100 parts by weight of ethylene-vinyl acetate-glycidyl methacrylate copolymer (Sumitomo Chemical Co., Ltd., Bondfast 2A, vinyl acetate content 8%, glycidyl methacrylate content 3%). (NIPPER B manufactured by NOF CORPORATION) 2.
0 parts by weight, γ-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone, KBM503) 0.5 parts by weight, triallyl isocyanurate (manufactured by Nippon Kasei Co., TA
(IC) 2.0 parts by weight were mixed to prepare a solution which was uniformly dissolved in toluene so that the resin concentration became 20% by weight.
Then, this solution was uniformly applied onto a triacetate film using a roll coater, and the dried film was degassed to a polycarbonate film at 0.5 kgf / c.
It is pressure-bonded at a pressure of m ² and it is placed in an oven at 100 ° C.
It heated for a minute and the laminated body A was obtained.

Example 5 A laminate B using glass in place of the polycarbonate film in Example 4 was obtained by the same method.

Example 6 A laminate C using a polyester film in place of the triacetate film and glass in place of the polycarbonate film in Example 4 was obtained by the same method.

Next, a 180 ° peeling test was performed on the laminates of Examples 4 to 6 and Comparative Example under different temperature conditions.
Table 2 shows the results.

[0041]

[Table 2]

Example 7 Ethylene / vinyl acetate / maleic anhydride copolymer (MODIC, manufactured by Mitsubishi Chemical Industry Co., Ltd.)
E-100H, vinyl acetate content of about 20%, maleic anhydride content of about 0.5%) to 100 parts by weight of 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane (NOF Corporation) (Manufactured by Perhexa 3M) (2.0 parts by weight), γ-methacryloxypropyltrimethoxysilane (0.5 parts by weight), triallyl isocyanurate (1.0 parts by weight) are mixed and kneaded with a roll at 80 ° C. The film was formed to a film thickness of 100 μm. This membrane is sandwiched between a triacetate film (1) and a polycarbonate film (2), and degassed with a vacuum bag in a 130 ° C oven for 1 hour.
The laminate A was obtained by heating for 0 minutes.

Example 8 A laminate B using glass in place of the polycarbonate film in Example 7 was obtained by the same method.

[Example 9] A laminate C using a polyester film in place of the triacetate film and glass in place of the polycarbonate film in Example 7 was obtained by the same method.

Next, a 180 ° peel test was conducted on the laminates of Examples 7 to 9 and Comparative Example under different temperature conditions.
The results are shown in Table 3.

[0046]

[Table 3]

Example 10 Ethylene-ethyl acrylate-maleic anhydride copolymer (L, manufactured by Sumitomo Chemical Co., Ltd.)
X4110, ethylene content 91%, ethyl acrylate content 8%, maleic anhydride content 1%) 100 parts by weight, 1,1-bis (t-butylperoxy) 3,3,5
-Trimethylcyclohexane (Nippon Yushi Co., Ltd., Perhexa 3M) (2.0 parts by weight), γ-methacryloxypropyltrimethoxysilane (0.5 parts by weight), triallyl isocyanurate (1.0 parts by weight) were mixed, and the mixture was rolled at 80 ° C. After kneading, a calender was formed into a film having a thickness of 100 μm. This film is sandwiched between a triacetate film (1) and a polycarbonate film (2), and degassed with a vacuum bag.
A laminate A was obtained by heating in an oven at ℃ for 10 minutes.

[Example 11] A laminate B using glass in place of the polycarbonate film in Example 10 was obtained by the same method.

Example 12 A laminate C using a polyester film in place of the triacetate film and glass in place of the polycarbonate film in Example 10 was obtained by the same method.

Next, the laminates of Examples 10 to 12 and Comparative Example were subjected to a 180 ° peel test under different temperature conditions. The results are shown in Table 4.

[0051]

[Table 4]

Example 13 Ethylene-methacrylic acid,
Sodium ion type ionomer resin (Mitsui DuPont Polychemical Co., Ltd., Himilan 1856, methacrylic acid content 5%, Na ionization degree 40%) 10
2.0 parts by weight of 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane (Perhexa 3M, manufactured by NOF CORPORATION) and γ-methacryloxypropyltrimethoxysilane per 0 parts by weight. 0.5 parts by weight and 1.0 part by weight of triallyl isocyanurate were mixed and kneaded with a roll at 80 ° C., and then formed into a film having a thickness of 100 μm by a calendar. This film was sandwiched between a triacetate film (1) and a polycarbonate film (2), and heated in a 130 ° C. oven for 10 minutes while being deaerated with a vacuum bag to obtain a laminate A.

[Example 14] A laminate B using glass in place of the polycarbonate film in Example 13 was obtained by the same method.

Example 15 A laminate C using a polyester film in place of the triacetate film and glass in place of the polycarbonate film in Example 13 was obtained by the same method.

Next, the laminates of Examples 13 to 15 and the comparative example were subjected to a 180 ° peel test under different temperature conditions. Table 5 shows the results.

[0056]

[Table 5]

As is clear from the above results, the adhesive force of the laminate D using the acrylic pressure-sensitive adhesive is remarkably reduced when the temperature is increased. Therefore, when the treatment for aligning the liquid crystal is performed on the surface of the various laminated bodies, the heat cannot be endured, and there is a possibility that the adhesive interface may float or peel. On the other hand, various laminates using the adhesive composition of the present invention can be treated even at a high temperature of 70 ° C. without breaking the integrated structure.

In addition, a humidity and heat resistance test (50 ° C. × 95% RH ×
After visually inspecting the appearance of various laminates after 500 hours), the laminate D using the acrylic pressure-sensitive adhesive was found.
Was observed due to foaming at the adhesive interface.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a liquid crystal display device.

FIG. 2 is a cross-sectional view showing an example of a polarizing plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal cell 2,2 'Substrate 3,3' Transparent electrode 4,4 'Alignment layer 5 Liquid crystal layer 6 Polarizing plate 6'Polarizing film 6' 'Protective film 7 Analyzing plate

Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number in the agency FI Technical display area C09J 123/26 JCL C09J 123/26 JCL 131/04 JCK 131/04 JCK (31) Priority claim number 7-25715 (32) Priority Day 7 (1995) February 14 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application 7-25716 (32) Priority Day 7 (1995) ) February 14 (33) Priority claiming country Japan (JP)

Claims (9)

[Claims] 1. A substrate for manufacturing a liquid crystal display device comprising a liquid crystal cell in which a liquid crystal layer is provided on one surface of a substrate via a transparent electrode and an alignment layer, and a polarizing plate adhered to the other surface of the substrate. In the adhesive composition used for adhesion between
This adhesive composition is an ethylene-vinyl acetate copolymer; a copolymer of ethylene, vinyl acetate and an acrylate-based and / or methacrylate-based monomer; a copolymerization of ethylene, vinyl acetate, maleic acid and / or maleic anhydride. Copolymers; copolymers of ethylene and acrylate and / or methacrylate monomers with maleic acid and / or maleic anhydride; from the group consisting of ionomer resins in which the ethylene-methacrylic acid copolymers are bonded with metal ions An adhesive composition for a liquid crystal display device, which is a thermosetting adhesive containing at least one selected polymer as a main component. 2. The thermosetting adhesive is obtained by adding 0.1 to 10 parts by weight of an organic peroxide and 0.01 to 5 parts by weight of a silane coupling agent to 100 parts by weight of a polymer. The adhesive composition for a liquid crystal display device according to claim 1. 3. A thermosetting adhesive is obtained by adding 0.1 to 50 parts by weight of at least one of an acryloxy group-containing compound, a methacryloxy group-containing compound and an allyl group-containing compound to 100 parts by weight of a polymer. The adhesive composition for a liquid crystal display device according to claim 1 or 2. 4. The liquid crystal according to claim 1, wherein the thermosetting adhesive is formed by adding 1 to 200 parts by weight of a hydrocarbon resin to 100 parts by weight of the polymer. Adhesive composition for display device. 5. The adhesive composition for a liquid crystal display device according to claim 1, wherein the polymer is an ethylene-vinyl acetate copolymer, and the vinyl acetate content is 10 to 50% by weight. . 6. The polymer is a copolymer of ethylene, vinyl acetate, and an acrylate-based and / or methacrylate-based monomer, and has a vinyl acetate content of 10 to 50% by weight and an acrylate-based and / or methacrylate-based monomer content. The adhesive composition for liquid crystal display device according to any one of claims 1 to 4, wherein the ratio is 0.01 to 10% by weight. 7. The polymer is a copolymer of ethylene, vinyl acetate, maleic acid and / or maleic anhydride,
The vinyl acetate content is 10 to 50% by weight, and the content of maleic acid and / or maleic anhydride is 0.01 to 10% by weight, according to any one of claims 1 to 4. An adhesive composition for a liquid crystal display device. 8. A polymer comprising ethylene and an acrylate-based and / or methacrylate-based monomer and maleic acid and / or
Or a copolymer with maleic anhydride, wherein the content of the acrylate compound is 10 to 50% by weight, and the content of maleic acid and / or maleic anhydride is 0.01 to 10% by weight. The adhesive composition for a liquid crystal display device according to any one of claims 1 to 4. 9. The polymer according to claim 1, wherein the polymer is the ionomer resin, the content of methacrylic acid is 1 to 30% by weight, and the degree of ionization by metal ions is 5 to 80%. The adhesive composition for a liquid crystal display device according to item 1.