KR20110044149A - Optical laminate and method for producing the same - Google Patents

Abstract

PURPOSE: An optical laminate and manufacturing method thereof are provided to have excellent durability and thin film type thin and light characteristic by combining a plastic sheet and a liquid cell substrate. CONSTITUTION: A glass plate(1) and a plastic sheet(3) are combined through an adhesive layer(2). The adhesive layer includes a polyvinylalcohol system resin and is comprised of adhesive component. The adhesive component includes a silane coupling agent and adds cross-linking agent.

Description

Optical laminated body and its manufacturing method {OPTICAL LAMINATE AND METHOD FOR PRODUCING THE SAME}

This invention relates to the optical laminated body used suitably for a liquid crystal display device, Specifically, the plastics which make a polarizing plate a typical example through the adhesive bond layer on the glass plate which makes a liquid crystal cell substrate used as a center member of a liquid crystal display typical example An optical laminated body in which a sheet is laminated | stacked. Moreover, this invention relates also to the method of manufacturing this optical laminated body advantageously.

A polarizing plate is useful as an optical component which comprises a liquid crystal display device. As a polarizing plate, the thing of the structure which laminated | stacked the protective layer which consists of a transparent resin film on one side or both surfaces of the polarizing film which consists of polyvinyl alcohol-type resins through an aqueous adhesive etc. is used conventionally. As such a transparent resin film, a triacetyl cellulose film is often used because of its excellent optical transparency and moisture permeability. Even when the protective layer is provided only on one side of the polarizing film, on the other side of the polarizing film, a resin film having an optical function such as a phase difference function may serve as a protective function of the polarizing film and be laminated through an adhesive or an adhesive. many. The polarizing plate comprised in this way is bonded by an adhesive (also called a pressure-sensitive adhesive) to a liquid crystal cell board | substrate through another optical function layer as needed, and becomes a liquid crystal panel, and is integrated in a liquid crystal display device.

BACKGROUND ART Liquid crystal display devices are rapidly expanding in applications as thin display screens such as liquid crystal televisions, liquid crystal monitors, and personal computers. As the use is expanded in this way, further thinning is required for the members constituting it. As mentioned above, a polarizing plate is generally bonded to a liquid crystal cell using an adhesive, since it is easy to peel off from a liquid crystal cell and to join another polarizing plate in case of any problem after bonding. However, the pressure-sensitive adhesive usually requires a thickness of at least 20 µm in order to maintain a proper adhesive force, which is one obstacle in achieving thinning of the liquid crystal panel and the liquid crystal display device.

The liquid crystal cell side protective layer of a polarizing film is abbreviate | omitted, an adhesive layer is formed directly here, and there exists an attempt to reduce thickness by bonding this adhesive layer to a liquid crystal cell. However, in the state in which the polarizing film and the liquid crystal cell are directly bonded to the pressure-sensitive adhesive layer in this manner, when the heat resistance test exposed to high temperature is performed, the pressure-sensitive adhesive layer alone cannot absorb the shrinkage of the polarizing film sufficiently. Defects, such as peeling and foaming, may arise. Moreover, when the heat shock test (heat shock test) which repeats a high temperature state and a low temperature state is performed, after all, only an adhesive layer cannot fully absorb the expansion and contraction of a polarizing film, and the polarizing film may be broken.

As another attempt to reduce the thickness of the polarizing plate, for example, Japanese Patent No. 4306269 (Japanese Patent Laid-Open No. 2004-245924) discloses at least one surface of a polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin. After coating the epoxy resin composition of hardening, the technique of forming a protective film by hardening the composition is disclosed. However, durability is not enough in the state which bonded the polarizing plate which uses the hardened | cured material of an epoxy resin composition as a protective film to the liquid crystal cell via an adhesive layer, and the polarizing film might also be broken when a heat shock test was performed, for example. In addition, Japanese Patent No. 4306270 (Japanese Patent Laid-Open Publication No. 2004-245925) discloses a composition whose main component is an epoxy resin which does not contain an aromatic ring in a polarizing film in which a dichroic dye is adsorbed and oriented in a polyvinyl alcohol-based resin. The technique which bonds a protective film through the adhesive agent and makes a polarizing plate is disclosed.

On the other hand, Japanese Patent No. 3695484 (Japanese Patent Laid-Open No. 9-159828) discloses a ternary copolymer of ethylene, an acrylate-based or methacrylate-based monomer, maleic acid or maleic anhydride on one surface of a polarizing film. A technique for forming a polarizing plate having an adhesive layer by forming an adhesive layer composed of a photocurable adhesive containing a predetermined amount of an unsaturated compound such as a photosensitizer and an acryloyloxy group-containing compound, respectively, and the technique of adhering the polarizing plate to the liquid crystal cell substrate through the adhesive layer It is disclosed and providing the protective layer which consists of said photocurable adhesive agent on the other surface of a polarizing film is also described.

However, in the case where the polarizing plate is bonded to the liquid crystal cell substrate through the adhesive disclosed in this document, in the heat resistance test or the heat shock test, a large problem is not seen in the small size liquid crystal cell, but the medium to large size liquid crystal cell When the polarizing plate is peeled off from the surface of the liquid crystal cell substrate or there is a problem that the polarizing film is broken. Moreover, although the optical laminated body which bonded the polarizing plate to the liquid crystal cell board | substrate using this adhesive agent can be made thin, the polarizing plate once bonded to the liquid crystal cell cannot peel it easily. Therefore, when any problem is found in the inspection after the bonding, the liquid crystal cell cannot be reused unless a process such as treatment with a special organic solvent is performed, and economic merits are insufficient.

Japanese Patent No. 4093891 (Japanese Patent Laid-Open No. 2004-4636) discloses a technique of supplying a polarizing plate from a roll and bonding it directly to a liquid crystal cell substrate via an adhesive.

The objective of this invention is providing the optical laminated body excellent in thin-light weight and durability by bonding the plastic sheet which makes a polarizing plate a representative example, and the glass plate which makes a liquid crystal cell substrate a typical example through a specific adhesive agent. Another object of the present invention is to provide an advantageous method for producing such an optical laminate.

The present invention includes the following inventions.

[1] An optical laminated body in which a glass plate and a plastic sheet are bonded through an adhesive layer, and the adhesive layer is formed of an adhesive composition containing a polyvinyl alcohol-based resin.

[2] The optical laminate according to [1], wherein the adhesive composition for forming the adhesive layer further contains a silane coupling agent. This form is preferred.

[3] The optical laminate according to [1] or [2], wherein the adhesive composition further contains a crosslinking agent.

[4] The optical laminate according to any one of [1] to [3], wherein the adhesive layer has a thickness of 5 µm or less. This form is suitable for thickness reduction of an optical laminated body.

[5] The optical laminate according to any one of [1] to [4], wherein the glass plate is a liquid crystal cell substrate.

[6] The optical laminate according to any one of [1] to [5], wherein the plastic sheet is a polarizing plate having a polarizing film in which a dichroic dye is adsorbed and oriented in polyvinyl alcohol-based resin.

[7] The optical laminate according to [6], wherein the polarizing plate includes the polarizing film and a transparent protective layer formed on at least one surface thereof.

[8] The polarizing plate includes the polarizing film and a transparent protective layer formed on one surface thereof, and the surface of the polarizing film opposite to the transparent protective layer is directly bonded to the liquid crystal cell substrate through the adhesive layer. ] An optical laminated body. This form is preferred.

[9] The polarizing plate includes a polarizing film, a transparent protective layer formed on one side thereof, and a phase difference plate laminated on the other side of the polarizing film, the phase difference plate side being bonded to the liquid crystal cell substrate through the adhesive layer. The optical laminated body as described in [7]. This form is also preferable.

[10] A method of manufacturing an optical laminate in which a plastic sheet is bonded to a glass plate, wherein the method comprises a layer of an adhesive composition comprising an aqueous solution containing a polyvinyl alcohol resin on at least one of the bonding surfaces of the glass plate and the plastic sheet, respectively. A step of forming an adhesive composition layer for preparing a layer, a bonding step of bonding the glass plate and the plastic sheet through the layer of the adhesive composition, and a bonding product obtained in the bonding step to be inspected to remove a bonded product from which a defect is detected. An inspection process and the hardening process which hardens the layer of the adhesive composition which exists in the joined article which a defect was not detected through the said inspection process are provided.

[11] The method of [10], wherein the glass plate is a liquid crystal cell substrate, and the plastic sheet is a polarizing plate having a polarizing film in which a dichroic dye is adsorbed and oriented in polyvinyl alcohol-based resin.

[12] The method according to [10] or [11], wherein the bonded article whose defect is detected in the inspection step is configured to return the glass plate to the formation step of the adhesive composition layer after the plastic sheet is peeled off.

Since the optical laminated body of this invention can bond a plastic sheet directly to a glass plate through an adhesive bond layer, the thickness can be reduced, and also the adhesiveness of a glass plate and a plastic sheet becomes favorable. In particular, when the liquid crystal cell substrate is a glass plate and the polarizing plate is a plastic sheet, since the thickness can be reduced in comparison with a conventional optical laminate in which the polarizing plate is bonded to the liquid crystal cell substrate via an adhesive layer, the optical laminate, Furthermore, the weight reduction of a liquid crystal panel can be aimed at, and the adhesiveness of a polarizing plate and a liquid crystal cell board | substrate also becomes favorable. Moreover, the optical laminated body which can fully endure the heat processing at the time of an apparatus assembly, and the environmental conditions at the time of using an apparatus can be provided by using an adhesive agent instead of an adhesive for bonding a liquid crystal cell board | substrate and a polarizing plate.

In addition, according to the method of the present invention, the above-described optical laminate can be produced advantageously. In particular, after a joining process and before a hardening process, an inspection process is provided, and when defects, such as a wound of a surface, presence of a foreign material, curling of a bubble, or axial shift | offset, are detected, it joins the bonded article which detected the defect. Since it is going to let it out, an optical laminated body can be manufactured with a high yield. Moreover, the adhesive composition which consists of aqueous solution is used for the joining of the glass plate which makes a liquid crystal cell board | substrate a representative example, and the plastic sheet which makes a polarizing plate a representative example, and can easily peel this plastic sheet from a glass plate before going through a hardening process. have. Therefore, after the defect was detected in the said inspection process and sent out of the manufacturing line, after peeling a plastic sheet from it, the adhesive composition layer mentioned above through the simple process of washing an adhesive composition by water washing, etc. Since it can return to the formation process of, the production efficiency of an optical laminated body can be improved further.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic cross section which shows the basic laminated constitution of the optical laminated body which concerns on this invention.
It is a cross-sectional schematic diagram which shows one form of the laminated constitution of the optical laminated body which concerns on this invention.
It is a cross-sectional schematic diagram which shows the other layer structure of the optical laminated body which concerns on this invention.

In the present invention, as shown in the cross-sectional schematic diagram in FIG. 1, the glass sheet 1, which is typically a liquid crystal cell substrate, and the plastic sheet 3, which is typically a polarizing plate, are bonded through an adhesive layer 2 to form an optical laminate ( 10). The adhesive layer 2 is formed of an adhesive composition containing a polyvinyl alcohol-based resin. First, the adhesive composition and the adhesive bond layer 2 formed from it are demonstrated, and description is advanced in order of the glass plate 1 and the plastic sheet 3 after that.

Adhesive Composition

<Polyvinyl alcohol resin>

In this invention, in order to adhere | attach the glass plate 1 and the plastic sheet 3, the adhesive composition containing polyvinyl alcohol-type resin is used. This adhesive composition is usually used in the form of an aqueous solution. Aqueous solutions of polyvinyl alcohol-based resins have conventionally been used in the field of polarizing plates for the adhesion of a polarizing film made of polyvinyl alcohol-based resin and a transparent protective film having a triacetyl cellulose film bonded to at least one side thereof. It was discovered by the present inventors to express high adhesive force, when the plastic sheet which makes a polarizing plate a representative example, and the liquid crystal cell board | substrate is used for adhesion | attachment of glass which makes a representative example.

Polyvinyl alcohol-type resin which becomes a main component of an adhesive composition is obtained by saponifying a polyvinyl acetate type resin. As polyvinyl acetate type resin, the copolymer etc. of vinyl acetate and the other monomer copolymerizable with it besides the polyvinyl acetate which is a homopolymer of vinyl acetate are illustrated. As another monomer copolymerized with vinyl acetate, unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ether, acrylamide which has an ammonium group, etc. are mentioned, for example. It is preferable that the polyvinyl alcohol-type resin contained in such an adhesive composition has a suitable degree of polymerization, For example, when it is set as the aqueous solution of 4 weight% concentration, it is preferable that the viscosity exists in the range of 4 mPa * sec-50 mPa * sec, Furthermore, it is more preferable to exist in the range of 6 mPa * sec-30 mPa * sec.

The degree of saponification of the polyvinyl alcohol-based resin included in the adhesive composition is not particularly limited, but is generally 80 mol% or more, and more preferably 90 mol% or more. When the saponification degree of the polyvinyl alcohol-type resin contained in an adhesive composition is low, there exists a tendency for the water resistance of the adhesive bond layer 2 to become inadequate easily.

It is preferable that the polyvinyl alcohol-type resin contained in an adhesive composition is modified. Examples of such modified polyvinyl alcohol-based resins include acetoacetyl group-modified polyvinyl alcohol-based resins, anion-modified polyvinyl alcohol-based resins, and cation-modified polyvinyl alcohol-based resins. When such modified polyvinyl alcohol-based resin is used, it is preferable because there is an advantage that the water resistance of the adhesive layer is improved.

The acetoacetyl group-modified polyvinyl alcohol-based resin has an acetoacetyl group (CH ₃ COCH ₂ CO-) in addition to the hydroxyl group constituting the polyvinyl alcohol skeleton, and may have other groups such as an acetyl group. This acetoacetyl group exists in the state which the hydrogen atom of the hydroxyl group is substituted typically. The acetoacetyl group-modified polyvinyl alcohol-based resin can be produced, for example, by a method of reacting polyvinyl alcohol with diketene. The acetoacetyl group-modified polyvinyl alcohol-based resin is preferable in improving the durability of the adhesive layer 2 because it has acetoacetyl group which is a highly reactive functional group. Moreover, when hardening an adhesive composition with an active energy ray, since it is excellent in sclerosis | hardenability, the polyvinyl alcohol-type resin modified by the acetoacetyl group is preferable.

There is no restriction | limiting in particular if content of acetoacetyl group in acetoacetyl group modified polyvinyl alcohol-type resin is 0.1 mol% or more. Content of the acetoacetyl group here is the value which expressed the mole fraction of the acetoacetyl group with respect to the total amount of the hydroxyl group, acetoacetyl group, and other ester groups (acetyl group etc.) in polyvinyl alcohol-type resin in%, below. Acetoacetylation degree ”in some cases. When the acetoacetylation degree in polyvinyl alcohol-type resin is less than 0.1 mol%, the effect which improves the water resistance of an adhesive bond layer will not necessarily be enough. Acetoacetylation degree in polyvinyl alcohol-type resin is about 0.1 mol%-40 mol%, Furthermore, it is preferable that it is 1 mol%-20 mol%, Especially 2 mol%-7 mol%. When the acetoacetylation degree exceeds 40 mol%, the improvement effect of water resistance will become small.

The anion-modified polyvinyl alcohol-based resin contains an anionic group, typically a carboxyl group (-COOH) or a salt thereof, in addition to the hydroxyl group constituting the polyvinyl alcohol skeleton, and may have other groups such as acetyl group. . The anion-modified polyvinyl alcohol-based resin can be produced, for example, by a method of copolymerizing an unsaturated monomer having an anionic group (typically a carboxyl group) with vinyl acetate and subsequently saponifying. On the other hand, the cation-modified polyvinyl alcohol-based resin contains a cationic group, typically a tertiary amino group or a quaternary ammonium group, in addition to the hydroxyl group constituting the polyvinyl alcohol skeleton, and may have other groups such as acetyl group or the like. do. The cation-modified polyvinyl alcohol-based resin can be produced, for example, by a method of copolymerizing an unsaturated monomer having a cationic group (typically a tertiary amino group or a quaternary ammonium group) with vinyl acetate and subsequently saponifying.

The adhesive composition used in the present invention may, of course, contain two or more of the above-described modified polyvinyl alcohol-based resins, and unmodified polyvinyl alcohol-based resins (specifically, complete or partial saponified polyvinyl acetate). ) And both of the above-described modified polyvinyl alcohol-based resins.

A commercially available suitable polyvinyl alcohol-type resin can be used for the adhesive composition for forming an optical laminated body. Specifically, for example, "PVA-117H" sold by Kuraray as a polyvinyl alcohol having a high degree of saponification, "Gosenol NH-20" sold by Nippon Kosei Kagaku Kogyo Co., Ltd., Aceto "Kosepimer Z" series sold by Nippon Kosei Kagaku Kogyo Co., Ltd. as an acetyl group-modified polyvinyl alcohol, "KL-318" sold by Kuraray Co., Ltd. as anion-modified polyvinyl alcohol, and CM-318 and Nippon Kosei, sold by KM-118 and Nippon Kosei Kagaku Kogyo Co., Ltd. "Kosepimer K-210" sold by Kagaku Kogyo Co., Ltd., etc. are mentioned.

The concentration of the polyvinyl alcohol-based resin in the adhesive composition is not particularly limited, but when used in the form of an aqueous solution, it is preferable that the polyvinyl alcohol-based resin is in the range of 1 part by weight to 20 parts by weight with respect to 100 parts by weight of water. Especially, it is more preferable to be in a range of 1 weight part-15 weight part, Furthermore, 1 weight part-10 weight part, especially 3 weight part-10 weight part. When the concentration of the polyvinyl alcohol-based resin is less than 1 part by weight with respect to 100 parts by weight of water, the adhesiveness tends to be lowered, and when the concentration is too large, the optical property of the optical laminate obtained tends to be lowered. have. Although water used for this adhesive composition is not specifically limited, such as pure water, ultrapure water, tap water, etc., Pure water or ultrapure water is preferable from a viewpoint of maintaining the uniformity and transparency of the adhesive bond layer formed. Moreover, alcohol, such as methanol and ethanol, can also be added to aqueous adhesive solution.

<Other components constituting the adhesive composition>

In this invention, in order to improve the adhesiveness of an adhesive bond layer and a glass plate, it is preferable to contain a silane coupling agent in the adhesive composition for forming the adhesive bond layer 2, and especially a silane coupling is carried out in the aqueous solution containing polyvinyl alcohol-type resin. It is preferable to mix | blend a ring agent.

The silane coupling agent is a compound in which a hydrolyzable group such as an alkoxy group is bonded to a silicon atom, and an organic group having a reactive functional group such as an amino group, an epoxy group, a (meth) acryloyl group, a vinyl group, a halogeno group, or a mercapto group is bonded. Can be. Specific examples thereof include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- ( 2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl Triethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimeth Methoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like. You may use combining 2 or more types of silane coupling agents. Among these, in consideration of the solubility in water and the usable time (pot life) as an adhesive, a silane coupling agent having an epoxy group, an amino group or a mercapto group is preferable, for example, 3-glycidoxypropyltrimethoxy Silane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like are preferable.

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

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer Copolymers containing mercaptopropyl groups, such as 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer;

Mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, and mercaptomethyltri Copolymers containing mercaptomethyl groups, such as ethoxysilane-tetraethoxysilane copolymers;

3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltrier Methoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-methacryloyloxypropylmethyl Copolymers containing methacryloyloxypropyl groups, such as diethoxysilane-tetraethoxysilane copolymers;

3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane- Tetramethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloyl Oxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane Copolymers containing acryloyloxypropyl groups, such as copolymers;

Vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetraethoxysilane co Polymers, vinylmethyldimethoxysilane-tetramethoxysilane copolymers, vinylmethyldimethoxysilane-tetraethoxysilane copolymers, vinylmethyldiethoxysilane-tetramethoxysilane copolymers, and vinylmethyldiethoxysilane-tetrae Vinyl group-containing copolymers such as oxysilane copolymers;

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-aminopropyl Amino group-containing copolymers such as methyldiethoxysilane-tetramethoxysilane copolymer and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer.

Since these silane coupling agents are liquid in most cases, they can be mixed with an aqueous solution containing polyvinyl alcohol-based resin as it is. The compounding quantity of the silane coupling agent in an adhesive composition is about 0.01 weight part-50 weight part normally with respect to 100 weight part of polyvinyl alcohol-type resins, Preferably it is used in the ratio of 0.03 weight part-30 weight part. Since the adhesiveness of an adhesive bond layer and glass improves that the quantity of a silane coupling agent with respect to 100 weight part of polyvinyl alcohol-type resins is 0.01 weight part or more, especially 0.03 weight part or more, it is preferable. Moreover, since the amount tends to be 50 weight part or less, especially 30 weight part or less, since the bleeding-out of a silane coupling agent from an adhesive bond layer tends to be suppressed.

A crosslinking agent can be contained in the adhesive composition for forming the adhesive bond layer 2 in this invention. The crosslinking agent may be blended in an aqueous solution of a polyvinyl alcohol resin that does not contain a silane coupling agent, or a crosslinking agent may be blended in an aqueous solution of a polyvinyl alcohol resin together with a silane coupling agent. It is preferable to contain.

The crosslinking agent should just be a compound which has a functional group which has reactivity with polyvinyl alcohol-type resin, and what has conventionally been used in the polyvinyl alcohol-type adhesive agent can be used without a restriction | limiting. When the compound which can be a crosslinking agent is published for each functional group, the isocyanate compound which has at least 2 isocyanate group (-NCO) in a molecule | numerator; An epoxy compound having at least two epoxy groups (crosslinked -O-) in the molecule; Mono- or di-aldehydes; Organic titanium compounds; Inorganic salts of divalent or trivalent metals such as magnesium, calcium, iron, nickel, zinc, and aluminum; Metal salts of glyoxylic acid; Methylolmelamine and the like.

As an example of the isocyanate compound used as a crosslinking agent, tolylene diisocyanate, hydrogenated tolylene diisocyanate, the adduct of trimethylol propane and tolylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, these Ketooxime block water, a phenol block water, etc. are mentioned.

Specific examples of the epoxy compound to be a crosslinking agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, di- or tri-glycidyl ether of glycerin, 1,6-hexanediol diglycidyl ether, trimethyl Water-soluble polyamide epoxy resin obtained by reacting epichlorohydrin with polyamide polyamine which is a reaction product of all propane triglycidyl ether, diglycidyl aniline, diglycidyl amine, polyalkylene polyamine and dicarboxylic acid, etc. Can be mentioned.

Specific examples of the monoaldehydes used as crosslinking agents include formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, and the like, and specific examples of the dialdehydes are glyoxal, malondialdehyde, succinic aldehyde, malealdehyde, and malealdehyde. And phthaldialdehyde.

As for the organic titanium compound used as a crosslinking agent, various things are sold from Matsumoto Fine Chemical Co., Ltd. It is suitable for this invention from the homepage (internet <URL: http://www.m-chem.co.jp/products/products1.html>, September 6, 2010 search) of the organic titanium compound of the company. When the water-soluble organic titanium compound used is published in the order of its formula, the chemical name of the verb, and the brand name of the verb, there are the following.

[(CH ₃ ) ₂ CHO] ₂ Ti [OCH ₂ CH ₂ N (CH ₂ CH ₂ OH) ₂ ] ₂ : Chemical name "titanium diisopropoxybis (triethanol aluminate)" as the verb refers to the product name "Orga Tics TC-400 ",

_{(HO) 2 Ti [OCH (} CH 3) COO -] 2 (NH 4 +) 2: Chemical name company speak "titanium lactate ammonium salt", trade name of the company "Organic ticks TC-300",

(HO) ₂ Ti [OCH (CH ₃ ) COOH] ₂ : The chemical name "titanium lactate" referred to by the verb, the brand names "Orgatics TC-310" and "Orgatics TC-315".

The metal salt of glyoxylic acid is preferably an alkali metal salt or an alkaline earth metal salt, and examples thereof include sodium glyoxylate, potassium glyoxylate, magnesium glyoxylate and calcium glyoxylate.

Among these crosslinking agents, epoxy compounds including soluble polyamide epoxy resins described above, aldehydes, methylolmelamine, alkali metal or alkaline earth metal salts of glyoxylic acid, and the like are suitably used.

It is preferable that the crosslinking agent is melt | dissolved in water with polyvinyl alcohol-type resin, and forms the adhesive composition. However, as described below, since the amount of the crosslinking agent in the aqueous solution may be slightly, it can be used as the crosslinking agent as long as it has a solubility of at least about 0.1% by weight relative to water. Of course, the compound which has solubility in water of the grade generally called water solubility is suitable as a crosslinking agent used for this invention.

Although the compounding quantity of a crosslinking agent is designed suitably according to the kind of polyvinyl alcohol-type resin, etc., it is about 5 weight part-60 weight part normally with respect to 100 weight part of polyvinyl alcohol-type resin, Preferably it is 10 weight part-50 weight part. . By mix | blending a crosslinking agent in this range, favorable adhesiveness is obtained. As described above, in order to improve the durability of the adhesive layer, acetoacetyl group-modified polyvinyl alcohol-based resin is preferably used, but even in this case, 5 parts by weight to 60 parts by weight of the crosslinking agent based on 100 parts by weight of the polyvinyl alcohol-based resin. In addition, it is preferable to mix | blend in the ratio of 10 weight part-50 weight part further. When the blending amount of the crosslinking agent is too large, the reaction of the crosslinking agent proceeds in a short time, and the adhesive composition tends to gel prematurely. As a result, the pot life becomes extremely short, making it unsuitable for industrial use.

In the adhesive composition, conventionally known appropriate additives such as plasticizers, antistatic agents and fine particles may be blended within a range that does not impair the effects of the present invention.

Adhesive Layer

In this invention, the adhesive composition demonstrated above on at least one surface of the bonding surface of the glass plate 1 and the plastic sheet 3, Preferably the layer of the adhesive composition which consists of aqueous solution which mix | blended each above component is provided, and the adhesive agent The glass plate 1 and the plastic sheet 3 are bonded together through the layer of the composition, and the layer is cured to form an adhesive layer 2. The thickness of the adhesive bond layer 2 can be 5 micrometers or less, and usually 0.001 micrometer-about 5 micrometers, Preferably it is 0.01 micrometer-2 micrometers, More preferably, it is the range of 0.05 micrometer-2 micrometers. When the thickness of an adhesive bond layer exceeds 5 micrometers, there exists a possibility that it may lead to the appearance defect of the plastic sheet 3.

[Glass plate]

Various things generally called glass can be used for the glass plate 1 by which the plastic sheet 3 is bonded through the adhesive bond layer 3. As mentioned above, this invention is especially useful when the glass plate 1 is a liquid crystal cell board | substrate which comprises a liquid crystal display device. A liquid crystal cell board | substrate sandwiches a liquid crystal between another board | substrate, and comprises a liquid crystal cell, This liquid crystal cell becomes a core member of a liquid crystal display device. The glass constituting the liquid crystal cell substrate may be a variety of generally known glass plates such as soda lime glass, low alkali borosilicate glass, alkali alumino borosilicate glass, but an alkali free glass is particularly preferably used for the liquid crystal cell.

[Plastic sheet]

The plastic sheet 3 bonded to the glass plate 1 through the adhesive layer 2 can also be used without limitation as long as the resin expressing the adhesive ability by the aqueous solution of polyvinyl alcohol-based resin becomes the bonding surface to the glass plate 1. have. As a resin which expresses adhesive ability by the aqueous solution of polyvinyl alcohol-type resin, Cellulose acetate resin containing polyacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, polyvinyl alcohol-type resin, And linear olefin resins, polyethylene terephthalate resins, and acrylic resins, including cycloolefin resins and polypropylene resins.

Among these, this invention expresses high adhesive force with respect to the plastic sheet | seat which a cellulose acetate type resin or polyvinyl alcohol-type resin becomes a bonding surface to the glass plate 1. If necessary, the surface bonded to the glass plate 1 of the plastic sheet 3 is subjected to a treatment for facilitating adhesion such as a saponification treatment or a corona discharge treatment, followed by formation of an adhesive layer and further bonding to the glass plate 1. Can also be provided to. For example, when a cellulose acetate type resin becomes a bonding surface to the glass plate 1, the adhesive force by the aqueous solution of polyvinyl alcohol-type resin can be heightened more by performing a saponification process to that surface. In addition, even when the chain olefin resin, including cycloolefin resin or polypropylene resin, becomes the bonding surface to the glass plate 1, the polyvinyl alcohol system is subjected to a treatment that facilitates adhesion such as corona discharge treatment on the surface. High adhesive force by the aqueous solution of resin will be expressed.

The thickness of the plastic sheet 3 is not particularly limited as long as it can be bonded to the glass plate 1. However, since the thickness of the plastic sheet 3 is preferably provided for bonding to the glass plate 1 in a rolled shape, the plastic sheet 3 is generally considered. As 500 micrometers or less are preferable, Furthermore, 300 micrometers or less, especially 200 micrometers or less are more preferable.

<Polarizing plate>

As mentioned above, the optical laminated body of this invention is a polarizing plate in which the glass plate 1 in FIG. 1 is a liquid crystal cell board | substrate, and the plastic sheet 3 has a polarizing film by which the dichroic dye was adsorbed-oriented to polyvinyl alcohol-type resin. Especially useful in the case. Although the above-mentioned polarizing film itself may be used as the plastic sheet 3 alone, but since the polarizing film alone is weak, it is transparent to at least one surface thereof, especially the surface opposite to the surface bonded to the liquid crystal cell substrate 1. What provided the protective layer is used preferably.

It is a cross-sectional schematic diagram which shows one form of the laminated constitution of the optical laminated body which concerns on this invention. In this aspect, the transparent protective layer 7 is provided on one surface of the polarizing film 6 to be the polarizing plate 5, and the surface of the polarizing film 6 on the opposite side to the surface on which the transparent protective layer 7 is provided. The direct laminated body is bonded to the liquid crystal cell substrate 1 via the adhesive bond layer 2, and the optical laminated body 11 is comprised. That is, in the optical laminated body 11 of FIG. 2, the polarizing film 6 is laminated | stacked in contact with the adhesive bond layer 2, and is transparent to the surface on the opposite side to the adhesive bond layer 2 in the polarizing film 6 The protective layer 7 is laminated.

It is a cross-sectional schematic diagram which shows the other layer structure of the optical laminated body which concerns on this invention. In this aspect, the transparent protective layer 7 is provided on one side of the polarizing film 6, and the appropriate resin layer 8 is provided on the other side of the polarizing film 6 to be the polarizing plate 5. The resin layer 8 side is bonded to the liquid crystal cell board | substrate 1 through the adhesive bond layer 2, and the optical laminated body 12 is comprised.

Thus, although the polarizing plate 5 may contain what kind of layer as long as it contains the polarizing film 6, the layer other than the polarizing film 6 may be two or less layers, especially one layer or two layers. It is preferable from a viewpoint of thinning an optical laminated body or a liquid crystal panel, protecting. From such a viewpoint, the polyvinyl alcohol-type resin film surface (polarizing film) which has the transparent protective layer 7 on one side of the polarizing film 6 as shown in FIG. 2, and is opposite to the transparent protective layer 7 The form in which the liquid crystal cell substrate 1 is bonded through the adhesive layer 2 directly on the surface) is one of the preferable ones. When employ | adopting the form shown in FIG. 2, although it changes also with the kind of the transparent protective layer 7, the thickness of the polarizing plate 5 can be 100 micrometers or less, for example.

<Polarizing film>

As for the polarizing film 6 which comprises the polarizing plate 5, a dichroic dye is adsorption-oriented to polyvinyl alcohol-type resin. More specifically, the thing in which the dichroic dye was adsorption-oriented to the uniaxially stretched polyvinyl alcohol-type resin film is used suitably.

The polyvinyl alcohol-based resin constituting the polarizing film is obtained by saponifying a polyvinyl acetate-based resin similarly to the polyvinyl alcohol-based resin constituting the adhesive composition described above. As polyvinyl acetate type resin, the copolymer etc. of vinyl acetate and the other monomer copolymerizable with this besides the polyvinyl acetate which is a homopolymer of vinyl acetate are illustrated. As another monomer copolymerizable with vinyl acetate, unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ether, etc. are mentioned, for example. The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 mol% to 100 mol%, preferably 98 mol% to 100 mol%. The polyvinyl alcohol-based resin constituting the polarizing film may be further modified, for example, polyvinyl formal, polyvinyl acetal modified with aldehydes, or the like can also be used. Moreover, the polymerization degree of the polyvinyl alcohol-type resin which comprises a polarizing film is about 1,000-10,000 normally, Preferably it is about 1,500-10,000.

What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of a polarizing film. The method of forming a polyvinyl alcohol-type resin into a film is not specifically limited, It can form into a film by a well-known method. Although the film thickness of a polyvinyl alcohol-type raw film is not specifically limited, For example, it is about 10 micrometers-150 micrometers.

A polarizing film is a process of uniaxially stretching the original film which consists of polyvinyl alcohol-type resin as mentioned above, the process of dyeing a polyvinyl alcohol-type resin film with a dichroic dye, and adsorbing the dichroic dye, and a dichroic dye. It manufactures through the process of processing the adsorbed polyvinyl alcohol-type resin film with aqueous solution of boric acid, and the process of washing with water after the process by aqueous solution of boric acid.

Uniaxial stretching may be performed before dyeing with a dichroic dye, may be performed simultaneously with dyeing, and may be performed after dyeing. When uniaxial stretching is performed after dyeing with a dichroic dye, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Moreover, it is also possible to uniaxially stretch in these several steps. At the time of uniaxial stretching, you may extend | stretch to 1 axis between rolls from which a circumferential speed differs, and you may extend | stretch to 1 axis using a hot roll. Moreover, dry extending | stretching, such as extending | stretching in air | atmosphere, may be sufficient, and the wet extending | stretching which extends in the state swollen with a solvent may be sufficient. The draw ratio is usually about 3 to 8 times.

Dyeing by the dichroic dye of a polyvinyl alcohol-type resin film is performed by immersing a polyvinyl alcohol-type resin film in the aqueous solution containing a dichroic dye, for example. As a dichroic dye, iodine, a dichroic organic dye, etc. are used. Moreover, it is preferable that the polyvinyl alcohol-type resin film is immersed in water before a dyeing process.

When using iodine as a dichroic dye, it is usually dyed by the method of immersing a polyvinyl alcohol-type resin film in the aqueous solution containing iodine and potassium iodide. The content of iodine in this aqueous solution is usually about 0.01 part by weight to 0.5 part by weight based on 100 parts by weight of water, and the content of potassium iodide is usually about 0.5 part by weight to 10 parts by weight with respect to 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is about 20 degreeC-40 degreeC normally, and the immersion time (dyeing time) in this aqueous solution is about 30 second-300 second normally.

On the other hand, when using a dichroic organic dye as a dichroic dye, it is usually dyed by the method of immersing a polyvinyl alcohol-type resin film in the dye aqueous solution containing water-soluble dichroic organic dye. Content of the dichroic organic dye in this dye aqueous solution is about 1 * 10 <^{-3> -1} * 10 <^-2> weight part normally with respect to 100 weight part of water. The dye aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dye aqueous solution is usually about 20 ° C. to 80 ° C., and the immersion time (dyeing time) in the dye aqueous solution is usually about 30 seconds to about 300 seconds.

The boric acid treatment after dyeing with a dichroic dye is performed by immersing the dyed polyvinyl alcohol-type resin film in boric acid containing aqueous solution. The content of boric acid in the boric acid-containing aqueous solution is usually about 2 parts by weight to 15 parts by weight, and preferably about 5 parts by weight to 12 parts by weight with respect to 100 parts by weight of water. When using iodine as a dichroic dye, it is preferable that boric acid containing aqueous solution contains potassium iodide. In this case, content of potassium iodide in boric-acid containing aqueous solution is about 2 weight part-20 weight part normally with respect to 100 weight part of water, Preferably it is about 5 weight part-15 weight part. Immersion time in boric-acid containing aqueous solution is about 100 second-1,200 second normally, Preferably it is about 150 second-600 second, More preferably, it is about 200 second-400 second. The temperature of the boric acid containing aqueous solution is 50 degreeC or more normally, Preferably it is 50 degreeC-85 degreeC.

The polyvinyl alcohol-based resin film after boric acid treatment is usually washed with water. A water washing process is performed by immersing the polyvinyl alcohol-type resin film which processed boric acid in water, for example. The temperature of water in a water washing process is about 5 to 40 degreeC normally, and immersion time is about 2 to 120 second. After water washing, a drying process is performed and a polarizing film is obtained. A drying process can be performed using a hot air dryer or a far infrared heater. Drying temperature is about 40-100 degreeC normally. The drying treatment time is usually about 120 seconds to about 600 seconds.

As described above, a polarizing film in which a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol-based resin film can be produced. The thickness of the obtained polarizing film can be about 5 micrometers-40 micrometers.

<Transparent protective layer>

The transparent protective layer 7 provided on at least one side of the polarizing film 6 is, for example, a chain olefin resin including a cellulose acetate resin, a cycloolefin resin, and a polypropylene resin, and a polymethyl methacrylate resin. It can be composed of a suitable thermoplastic resin film conventionally widely used as a material for forming a protective layer in the art, such as acrylic resin, polyimide resin, polycarbonate resin, polyester terephthalate resin and polyester resin including polyethylene terephthalate resin. . Moreover, the transparent protective layer 7 can also be comprised from hardened | cured material of an active energy ray curable resin composition. From the viewpoint of mass productivity and adhesiveness, among these, the film which consists of cellulose acetate type resin, cycloolefin type resin, linear olefin type resin, acrylic resin, or polyester type resin, or the hardened | cured material of active energy ray curable resin composition is transparent. It is preferable to use as the protective layer 7.

In the case where the transparent protective layer 7 is made of a thermoplastic resin film, the thickness thereof is usually about 10 µm to 80 µm, but is preferably set to a relatively thin thickness of about 10 µm to 50 µm. On the other hand, when the transparent protective layer 7 is comprised from the hardened | cured material of an active energy ray curable resin composition, the thickness can be 10 micrometers or less, for example, about 1 micrometer-10 micrometers.

The cellulose acetate type resin film used as the transparent protective layer 7 is a film which consists of a part of cellulose or a complete acetate ester, for example, a triacetyl cellulose film, a diacetyl cellulose film, etc. are mentioned. As such a cellulose acetate resin film, a suitable commercial item, such as "Fujitak TD80", "Fujitaek TD80UF" and "Fujitaek TD80UZ" sold by Fujifilm Co., Ltd., "" sold by Konica Minolta Opto Co., Ltd. " KC8UX2M "and" KC8UY "(both trade names) and the like can be used.

The cycloolefin resin used for the transparent protective layer 7 is, for example, a monomer composed of a cyclic olefin (cycloolefin) such as norbornene, tetracyclododecene (aka dimethanooctahydronaphthalene), or derivatives thereof. It is a thermoplastic resin having a unit (also called a thermoplastic cycloolefin resin). The cycloolefin resin may be a hydrogenated product of the ring-opening polymer of the cycloolefin, or a hydrogenated product of a ring-opening copolymer using two or more cycloolefins, and a cycloolefin and a chain olefin and / or a vinyl group. The addition copolymer with aromatic compound etc. which it has may be sufficient. A polar group may be introduce | transduced into cycloolefin resin.

When forming the transparent protective layer 7 using the addition copolymer of cycloolefin, a linear olefin, and / or the aromatic compound which has a vinyl group, as a linear olefin, ethylene, propylene, etc. are mentioned, The aromatic compound which has a vinyl group As styrene, (alpha) -methylstyrene, nuclear alkyl substituted styrene, etc. are mentioned. In such a copolymer, the unit of the monomer which consists of cycloolefin may be 50 mol% or less (preferably 15 mol%-50 mol%). In particular, in the case of constituting the transparent protective layer 7 using a ternary copolymer of a cycloolefin, a chain olefin, and an aromatic compound having a vinyl group, the unit of the monomer consisting of the cycloolefin can be made in a relatively small amount as described above. have. In such a terpolymer, the unit of the monomer which consists of a linear olefin, and the monomer which consists of an aromatic compound which has a vinyl group is about 5 mol%-about 80 mol%, respectively.

Cycloolefin resins are suitable commercially available products such as TOPAS ADVANCED POLYMERS GmbH, "TOPAS" sold by Polyplastics Co., Ltd. in Japan, "Aton" (ARTON) sold by JSR Co., Ltd., Nippon Xeon Co., Ltd. ZEONOR, ZEONEX, and Apel (APEL) (all trade names) sold by Mitsui Chemicals, Inc. may be used. When forming a cycloolefin resin into a film and making into a film, well-known methods, such as the solvent casting method and the melt-extrusion method, are used suitably. Moreover, for example, the film of the cycloolefin resin previously formed into a film, such as the "Zeonoa film" sold by Nippon Xeon Co., Ltd. and the "Aton film" sold by JSR Co., Ltd., is transparent-protected layer 7 It can also be used as.

It is preferable that the chain | stranded olefin resin used for the transparent protective layer 7 is polypropylene resin which makes propylene the main structural unit. In addition to being a homopolymer of propylene, the polypropylene resin may be copolymerized with propylene to another copolymerizable monomer having ethylene as a representative to about 10% by weight, for example, about 1% by weight to 10% by weight. It can form into a film used for the transparent protective layer 7 by forming into a film by well-known methods, such as a polypropylene resin resin, the solvent casting method, and the melt-extrusion method.

It is preferable that acrylic resin used for the transparent protective layer 7 is polymethyl methacrylate type resin which has methyl methacrylate as a main structural unit. Acrylic rubber particle | grains may be mix | blended with polymethyl methacrylate type resin. Moreover, it may be set as the multilayered structure which has a layer of the polymethyl methacrylate type resin which the light-diffusion agent was mix | blended, and the layer of the polymethyl methacrylate type resin which the light-diffusion agent is not mix | blended. Polymethyl methacrylate resin is usually formed into a film by melt extrusion method. In the case of a multilayer structure, a coextrusion method can be adopted.

It is preferable that the polyester resin used for the transparent protective layer 7 is polyethylene terephthalate resin which uses terephthalic acid and ethylene glycol as a main structural unit. The film can be formed into a film by a known method such as polyethylene terephthalate resin, solvent casting, melt extrusion, or the like, but the film is also stretched in one or two axes to have strength and to increase transparency. It is preferably used as the transparent protective layer 7.

On the other hand, the active energy ray curable resin composition used for the transparent protective layer 7 may contain an epoxy-type active energy ray curable compound, for example, It is also effective to mix | blend an oxetane compound. Thus, when containing an epoxy compound and also optionally containing an oxetane compound, a photocationic polymerization initiator is also mix | blended normally.

In addition to the epoxy compound and the oxetane compound which is an optional component, the active energy ray curable resin composition used for the transparent protective layer 7 is effective to contain a radically polymerizable compound, specifically, a (meth) acrylic compound. By using together a (meth) acrylic-type compound, it can be set as the transparent protective layer which is high in hardness, excellent in mechanical strength, and excellent in durability. Moreover, adjustment of the viscosity, hardening rate, etc. of an active energy ray curable resin composition can be performed more easily. In the active energy ray-curable resin composition for forming the transparent protective layer 7, the (meth) acrylic compound may be added up to about 70% by weight based on the total amount of the active energy ray-curable compound. As for the compounding quantity of a (meth) acrylic-type compound, it is more preferable to set it as 35 weight%-70 weight%, especially 40 weight%-60 weight%. When the compounding quantity of a (meth) acrylic-type compound exceeds 70 weight%, there exists a tendency for adhesiveness with a polarizing film to fall. When mix | blending such a (meth) acrylic-type compound, an optical radical polymerization initiator is further mix | blended.

The transparent protective layer 7 of the polarizing plate 5 may have a surface treatment layer on the surface opposite to the surface adhering to the polarizing film 6, and examples of such surface treatment include an antiglare treatment, a hard coating treatment, and an antistatic treatment. , Antireflection treatment, and the like. Moreover, the coating layer which consists of a liquid crystalline compound, its high molecular weight compound, etc. may be formed in the surface on the opposite side to the surface adhering to the polarizing film 6 of the transparent protective layer 7.

When the transparent protective layer 7 is a resin film, an adhesive agent is used for adhesion | attachment of the polarizing film 6 and the transparent protective layer 7. As an adhesive agent for this, the water-based adhesive agent which melt | dissolved or disperse | distributed the curable resin composition and adhesive component containing an active energy ray curable compound in water is mentioned.

It is preferable to make curable resin composition containing an active energy ray curable compound into an adhesive agent from a viewpoint of making a drying process unnecessary and raising productivity. In this case, it is preferable to use an epoxy type cationically polymerizable compound as an active energy ray curable compound. Moreover, it is also effective to mix | blend the oxetane compound which is cationically polymerizable similarly to an epoxy compound. Thus, when containing an epoxy compound and also optionally containing an oxetane compound, a photocationic polymerization initiator is also mix | blended normally. When using curable resin composition as an adhesive agent, after bonding the polarizing film 6 and the transparent protective layer 7 normally through a curable resin composition layer, this junction is irradiated with an active energy ray, and curable resin composition layer is made into Harden.

On the other hand, the water-based adhesive agent which melt | dissolved or disperse | distributed the adhesive component in water is preferable from a viewpoint of making an adhesive bond layer thin and the whole polarizing plate 5 thin. As such an aqueous adhesive agent, the adhesive composition which has polyvinyl alcohol-type resin and a urethane resin as a main component is mentioned. When polyvinyl alcohol-based resin is used as a main component of the water-based adhesive agent, the polyvinyl alcohol-based resin may be an anion-modified polyvinyl alcohol-based resin or an acetoacetyl group-modified polyvinyl alcohol in addition to partially saponified polyvinyl alcohol or fully saponified polyvinyl alcohol. Modified polyvinyl alcohol-based resins such as polyvinyl alcohol-based resins modified with methylol group and polyvinyl alcohol-based resins modified with cation may be used. When using polyvinyl alcohol-type resin as an adhesive agent, the adhesive agent is normally prepared as an aqueous solution of polyvinyl alcohol-type resin. The concentration of the polyvinyl alcohol-based resin in the adhesive is usually about 1 part by weight to 10 parts by weight, and preferably 1 part by weight to 5 parts by weight with respect to 100 parts by weight of water. Moreover, it is also effective to use a crosslinking agent together.

<Resin layer arrange | positioned at the liquid crystal cell board side of a polarizing plate>

As in the example shown in FIG. 3, when the resin layer 8 is provided on the liquid crystal cell substrate 1 side of the polarizing film 6, the resin layer 8 is provided on the opposite side of the polarizing film 6. In addition to being a transparent protective layer that is the same as or different from the transparent protective layer 7, the optical functional layer may be used. As an example of an optical function layer, the phase difference plate used for the purpose of compensation of the phase difference by a liquid crystal cell, compensation of a viewing angle, etc. are mentioned. As a retardation plate, For example, the birefringent film which consists of stretched films of various resins, the film in which the discotic liquid crystal and the nematic liquid crystal were orientated, and the coating film containing retardation expression substances, such as said liquid crystal and an inorganic layer shape compound, on a film base material (V) is formed and orientation fixed. In this case, a cellulose acetate-based resin film such as triacetyl cellulose is preferably used as a film substrate for supporting a coating film containing a phase difference expressing substance.

When a birefringent film made of a stretched film of resin is used as a retardation plate, a cellulose acetate resin, a cycloolefin resin, a polypropylene resin, or the like constitutes the retardation plate from the viewpoints of the retardation expression and stability of the retardation value. It is suitable as a resin material. These resin itself is the same as what was demonstrated previously as the resin film which comprises the transparent protective layer 7. By retarding or biaxially stretching these resin films, a phase difference can be provided and it can be set as a retardation plate. In this case, the draw ratio is usually 1.1 to 5 times, preferably 1.1 to 3 times.

The cellulose acetate-based resin film and the cycloolefin-based resin film are also commercially available. For example, examples of the cellulose acetate-based resin film to which the phase difference is provided include "KC4FR-T" and "KC4HR-T" sold by Konica Minolta Opto Co., Ltd. There are "Esshina" and "SCA40" sold by Ku Kogyo Co., Ltd. In addition, "Zenoa Film" sold by Nippon Xeon Co., Ltd. published earlier as an example of a cycloolefin resin film which can serve as the transparent protective layer 7, and "Aton Film" sold by JSR Co., Ltd. There is also a grade to which a phase difference is provided.

When the resin layer 8 is composed of a resin film containing a retardation plate, the polarizing film 6 and the resin layer are formed using the same adhesive as described for the adhesion of the preceding polarizing film 6 and the transparent protective layer 7. (8) can be bonded.

When praying to provide the polarizing plate 5 with the compensation function of the phase difference by a liquid crystal cell, the compensation function of a viewing angle, etc., as shown in FIG. 3, one side of the polarizing film 6 has a transparent protective layer ( 7), the retardation plate is laminated on the other side of the polarizing film 6 as the resin layer 8 to form a polarizing plate 5, and the retardation side is connected to the liquid crystal cell substrate through the adhesive layer 2 described above. The form joined to (1) is effective. Thus, even when laminating | stacking the phase difference plate on the surface used as the liquid crystal cell board | substrate 1 side of the polarizing film 6, the thickness of the whole polarizing plate 5 can be 200 micrometers or less. Moreover, if the resin layer 8 used as the transparent protective layer 7 and retardation plate is selected suitably, the thickness of the whole polarizing plate 5 can also be 100 micrometers or less.

[Method for Producing Optical Laminate]

Next, the manufacturing method of the optical laminated body which concerns on this invention is demonstrated. The optical laminated body demonstrated above can be advantageously manufactured by the method provided with each process shown below. Hereinafter, it demonstrates, quoting the code | symbol shown in FIG.

(a) Formation process of adhesive composition layer which provides the layer of adhesive composition which consists of aqueous solution containing polyvinyl alcohol-type resin in one or more of bonding surfaces of the glass plate 1 and the plastic sheet 3,

(b) a bonding step of bonding the glass plate 1 and the plastic sheet 3 through the layer of the adhesive composition,

(c) an inspection step of inspecting the bonded article obtained in the joining step and sending out the bonded article in which the defect is detected out of the production line, and

(d) The hardening process of hardening the layer of the adhesive composition which exists in the joined article which a defect was not detected through the said test process.

This manufacturing method is particularly useful when the glass plate 1 is a liquid crystal cell substrate and the plastic sheet 3 is a polarizing plate having the polarizing film described above. The polarizing plate may be a polarizing film alone or a laminate of other layers in advance as described above, but as described above with reference to FIGS. 2 and 3, the transparent protective layer 7 formed on at least one side of the polarizing film 6. Is preferably provided. As described above, when the polarizing plate 5 having at least the polarizing film 6 and the transparent protective layer 7 laminated thereon is a plastic sheet 1, the plastic sheet 1 is formed in a state in which each layer constituting the polarizing plate 5 is laminated. This is provided in the formation process (a) of the adhesive composition layer mentioned above. Hereinafter, each process shown above is demonstrated in order.

<Formation process (a) of adhesive composition layer>

In the formation process (a) of an adhesive composition layer, the layer of the adhesive composition which consists of aqueous solution containing a polyvinyl alcohol-type resin is provided in one or more of bonding surfaces of the glass plate 1 and the plastic sheet 3, respectively. At the time of formation of an adhesive bond layer, the method of apply | coating said adhesive composition to the bonding surface of the glass plate 1 and / or the bonding surface of the plastic sheet 3 can be employ | adopted, for example. Moreover, although it is one form of application | coating, each of the glass plate 1 and the plastic sheet 3 is supplied so that the plastic sheet 3 may be bonded to one end of the surface of the glass plate 1, and the above-mentioned adhesive composition is sprayed between them. You may employ | adopt the method of forming a layer of adhesive composition on a joining surface, and performing the following joining process continuously, pressing a roll from the outer side of the plastic sheet 3 with a roll.

The means for applying the adhesive composition to the bonding surface of the glass plate 1 and / or the bonding surface of the plastic sheet 3 is not particularly limited, for example, doctorblade, wire bar, slit coater, die coater, comma coater, gravure coater. Various coating methods can be used. In addition, since each coating system has an optimum viscosity range, the viscosity of the adhesive composition (aqueous solution) can be adjusted by adjusting the concentration of the polyvinyl alcohol-based resin in the adhesive composition.

<Joining Step (b)>

In the following bonding process (b), the glass plate 1 and the plastic sheet 3 are bonded together through the layer of the adhesive composition formed in the formation process (a) of the above adhesive composition layer. In this process, as described above, the method of supplying the plastic sheet 3 to the end of the surface of the glass plate 1 so as to be bonded through the layer of the adhesive composition, and pressing while pressing with a roll from the outside of the plastic sheet 3 is advantageous. Are employed. Thus, the method of joining to the other end of the surface of the glass plate 1 while pressing with a roll from the end of the surface of the glass plate 1 is advantageous from a viewpoint of suppressing curling of a bubble.

<Inspection process (c)>

In the inspection step (c), the bonded article obtained in the above bonding step (b) is inspected and the bonded article in which the defect is detected is sent out of the production line. Of course, if a defect is not detected, the said joined product will be sent to the next hardening process (d) as it is. In this inspection process (c), the presence or absence of the wound of a surface, the presence of a foreign material, the curling of a bubble, the presence or absence of axial shift | offset, etc. are examined. Such inspection can be performed by a method usually employed in the production stage of the liquid crystal panel.

In the inspection step (c), the bonded part whose defect is detected is sent out of the production line. In this step, since the layer of the adhesive composition which consists of aqueous solution containing polyvinyl alcohol-type resin is not hardened | cured yet, the plastic sheet 3 can be easily peeled from the glass plate 1. Therefore, the glass plate 1 after peeling off the plastic sheet 3 can easily remove the adhesive composition on the surface by water washing etc., and can return to the formation process (a) of an adhesive composition layer after washing | cleaning. The operation of returning the glass sheet 1 to the forming step (a) of the adhesive composition layer by removing the bonded product from which the defect is detected in the inspection step (c) out of the production line and peeling the plastic sheet 3 therefrom is accompanied by an adhesive layer. After joining the polarizing plate which was made to a liquid crystal cell board | substrate, when there exists any problem, it corresponds to the rework operation of peeling and reattaching the polarizing plate. In the present invention, although the plastic sheet 3 (typically a polarizing plate) is bonded to the glass plate 1 (typically a liquid crystal cell substrate) using an adhesive rather than an adhesive, such a rework is because the adhesive is an aqueous solution. There is an advantage that the operation can be easily performed.

Curing Step (d)

As for the joined article which passed the test because a defect was not detected in the inspection process (c), the layer of the adhesive composition which exists between the glass plate 1 and the plastic sheet 3 in the following hardening process (d) hardens. In the hardening process (d), the layer of an adhesive composition is hardened by high temperature drying, irradiation of an active energy ray, etc., and it is set as the adhesive bond layer 2. The hardening of the layer of adhesive composition often employs high temperature drying. When hardening by irradiation of an active energy ray, the active energy ray used may be an ultraviolet-ray, an X-ray, an electron energy ray, etc. Moreover, there also exists a method of hardening the layer of an adhesive composition by normal temperature standing. When hardening the layer of adhesive composition by high temperature drying, it is preferable to perform a process normally at 40 degreeC-80 degreeC for 1 minute-24 hours. When hardening the layer of an adhesive composition by irradiation of an active energy ray, an ultraviolet-ray is normally used and it is preferable to make the accumulated light quantity shown as a product of irradiation illumination intensity and irradiation time into 50 mJ / cm <2> -2000mJ / cm <2>. When hardening the layer of an adhesive composition by normal temperature standing, it is preferable to perform a process for 0.5 to 72 hours in the environment of 20 to 30 degreeC, and 20 to 80% of humidity normally.

[Liquid crystal display device]

The optical laminated body 10-12 of this invention arrange | positions another liquid crystal cell board | substrate on the opposite side to the surface where the polarizing plate 5 of the liquid crystal cell board | substrate 1 is bonded, and clamps a liquid crystal between them ( (Iii) it can be set as a liquid crystal cell or a liquid crystal panel. A liquid crystal display device is constituted by using this liquid crystal cell or liquid crystal panel as a display element. The liquid crystal cell itself in the state in which the liquid crystal was enclosed between two liquid crystal cell substrates was used as the liquid crystal cell substrate 1 in FIGS. 1-3, The polarizing plate was bonded to the surface of one or both sides according to this invention, and a liquid crystal panel It is common to use. Since the optical laminated body of this invention is excellent in durability with respect to a thermal shock test etc., the liquid crystal display device produced as mentioned above is also excellent in durability with respect to a thermal shock test etc., and also made thin and lightweight.

[Example]

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further more concretely, this invention is not limited by these examples. In the examples, "%" and "parts" indicating the content to the amount of use are based on weight unless otherwise specified.

Example 1

(a) Preparation of polyvinyl alcohol adhesive composition

Acetoacetyl group-modified polyvinyl alcohol having a saponification degree of 99.1 mol% (manufactured by Nippon Kosei Chemical Co., Ltd., trade name "Kosepimer Z-200", viscosity of 4% aqueous solution of 12.4 mPasec) was dissolved in pure water. , 10% aqueous solution was prepared. In this acetoacetyl group-modified polyvinyl alcohol aqueous solution, glyoxal as a crosslinking agent and 3-glycidoxy propyl trimethoxysilane as a silane coupling agent, and the solid content weight ratio of acetoacetyl group-modified polyvinyl alcohol: a crosslinking agent: a silane coupling agent It mixed with 1: 0.5: 0.1, and also diluted with pure water so that 3 parts of acetoacetyl-group modified polyvinyl alcohol may be added with respect to 100 parts of water, and the adhesive composition was prepared.

(b) Preparation of Optical Laminate

Polarizing plate [Sumitomo Chemical Co., Ltd. product] where the protective film which consists of triacetyl cellulose of thickness 40micrometer is bonded to one surface of the polarizing film in which iodine is adsorbed-oriented to a polyvinyl alcohol film through a polyvinyl alcohol-type adhesive agent; Trade name "SR0661A-XNSY", approximately 70 mu m thick]. On the other hand, the transparent glass substrate (what becomes a liquid crystal cell substrate) was wash | cleaned using the ultrasonic glass washing machine (made by MicroKiken Co., Ltd.). The above-mentioned polarizing plate is cut into 10 cm x 10 cm square size, and the adhesive composition shown in said (a) is respectively made to the polarizing film surface in which the protective film is not bonded, and the one surface of the transparent glass substrate after the said washing | cleaning, respectively. After the preparation, the mixture was applied within 30 minutes, and adhesive surfaces were bonded to each other. After leaving this at room temperature for 24 hours, it dried at 60 degreeC for 3 minutes, and produced the optical laminated body. The thickness of the adhesive bond layer after drying is about 0.1 micrometer.

[Example 2]

The crosslinking agent was changed to methylolmelamine, and the adhesive composition was prepared in the same manner as in Example 1 (a). Using this composition, the optical laminated body was produced by the method similar to (b) of Example 1.

[Examples 3 to 21]

As the polyvinyl alcohol, the followings were used in addition to the "high-cephamer Z-200" (hereinafter abbreviated as "Z-200" in Table 1) shown in Example 1. In following Table 1, it shows with the symbol shown first at each of the following each terms.

T-330: Anionized polyvinyl alcohol having a saponification degree of 96.5 mol% (Nippon Kosei Chemical Co., Ltd. make, trade name "Gosenol T-330", viscosity of 4% aqueous solution 30.0 mPasec).

KL-318: Anion-modified polyvinyl alcohol having a degree of saponification of 87.5 mol% [Kurare Co., Ltd., brand name "KL-318", 25.0 mPa sec of 4% concentration aqueous solution].

Z-100: Acetoacetyl-group-modified polyvinyl alcohol of 99.2 mol% of saponification degree (The Nippon Kosei Chemical Co., Ltd. make, brand name "Kosepimer Z-100", the viscosity of a 4% concentration aqueous solution 5.2mPa.sec.).

Z-210: Acetoacetyl-group-modified polyvinyl alcohol of 96.3 mol% of saponification degree (The Nippon Kosei Chemical Co., Ltd. make, brand name "Kosepimer Z-210", the viscosity of a 4% concentration aqueous solution 13.9 mPa.sec.).

Z-220: Acetoacetyl-group-modified polyvinyl alcohol of 92.5 mol% of saponification degree (The Nippon Kosei Chemical Co., Ltd. make, brand name "Kosepimer Z-220", the viscosity of a 4% concentration aqueous solution 13.2 mPa * sec).

Z-300: Acetoacetyl-group-modified polyvinyl alcohol of 98.5 mol% of saponification degree (The Nippon Kosei Chemical Co., Ltd. make, brand name "Kosepimer Z-300", the viscosity of 4% concentration aqueous solution 27.9 mPa * sec. "

Z-320: Acetoacetyl-group-modified polyvinyl alcohol of 92.8 mol% of saponification degree (The Nippon Kosei Chemical Co., Ltd. make, brand name "Kosepimer Z-320", the viscosity of 4% concentration aqueous solution 22.5 mPa * sec. "

Z-410: Acetoacetyl-group-modified polyvinyl alcohol of 97.8 mol% of saponification degree (The Nippon Kosei Chemical Co., Ltd. make, brand name "Kosepimer Z-410", the viscosity of 4% concentration aqueous solution 52.6 mPa * sec.).

As the crosslinking agent, the followings were used in addition to the glyoxal shown in Example 1 and the methylolmelamine shown in Example 2. In addition, in following Table 1, it shows with the symbol shown first at each of the following each terms.

TC-400: Organic titanium compound represented by the formula [(CH ₃ ) ₂ CHO] ₂ Ti [OCH ₂ CH ₂ N (CH ₂ CH ₂ OH) ₂ ] ₂ [manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "Orgatics" TC-400 "and the chemical name of the company are titanium diisopropoxy bis (triethanol aluminate)]. In addition, although this product is sold by the solution of 80% of active ingredients, and 20% of 2-propanol, the usage-amount shown below is the value converted into active ingredient concentration.

Glyoxylic acid Na: Sodium glyoxylate.

As the silane coupling agent, the followings were used in addition to the 3-glycidoxypropyltrimethoxysilane shown in Example 1 (hereinafter abbreviated as "3-GPTMS" in Table 1). In addition, in following Table 1, it shows with the symbol shown first at each of the following each terms.

N-APTMS: N- (2-aminoethyl) -3-aminopropyltrimethoxysilane.

3-APTMS: 3-aminopropyltrimethoxysilane.

3-MPTMS: 3-mercaptopropyltrimethoxysilane.

The above-mentioned polyvinyl alcohol (abbreviated as "PVA" in Table 1), a crosslinking agent, and a silane coupling agent are used to show the blending ratio of the polyvinyl alcohol: crosslinking agent as shown in Table 1, except that in Example 1 ( According to a), an adhesive composition was prepared. The compounding quantity of the silane coupling agent which is not described in Table 1 is the same as that of Examples 1 and 2 (weight ratio with respect to polyvinyl alcohol 1 is 0.1). In addition, in Example 4, 5, and 6, the crosslinking agent was not mix | blended. In Table 1, the compounding ratio of Example 1 and 2 was also shown. And the optical laminated body was produced by the method similar to (b) of Example 1 using each of these adhesive compositions.

[Example 22]

3 parts of acetoacetyl-group-modified polyvinyl alcohol "Gocephimer Z-200", 0.3 part of sodium glyoxylates as a crosslinking agent, and a silane coupling with respect to the same adhesive composition as Example 16, ie, 100 parts of water The adhesive composition which zein 3-glycidoxy propyl trimethoxysilane was mix | blended in the ratio of 0.3 part was used. On the other hand, instead of the polarizing plate used in Example 1 (b), a protective film made of triacetyl cellulose having a thickness of 80 μm through a polyvinyl alcohol-based adhesive on one side of the polarizing film in which iodine is adsorbed to the polyvinyl alcohol film. Is bonded, and the polarizing plate which the phase difference plate which consists of triacetyl cellulose of thickness 40micrometer is bonded to the other surface of a polarizing film through the polyvinyl alcohol-type adhesive [Sumitomo Chemical Co., Ltd. make, brand name "SRN231A", thickness about 150 μm] was prepared. And the retardation plate surface which consists of triacetyl cellulose of 40 micrometers in thickness of this polarizing plate is used as a bonding surface to a transparent glass substrate, the above-mentioned adhesive composition is used, and the others are optically laminated by the method similar to Example (b) of Example 1 A sieve was produced.

Comparative Example 1

To 20% aqueous solution of polyvinylpyrrolidone (made by Nippon Shokubai Co., Ltd., brand name "K-85W"), 3-glycidoxypropyl trimethoxysilane was used as a silane coupling agent, and polyvinylpyrrolidone: It mixed with the solid content weight ratio of a silane coupling agent so that it might be 1: 0.1, and also diluted with pure water so that polyvinylpyrrolidone may be 2 parts with respect to 100 parts of water, and the adhesive composition was prepared. Using this adhesive composition, an optical laminate was produced in the same manner as in Example (b).

Comparative Example 2

Instead of the polyvinyl alcohol adhesive composition, an acrylic pressure-sensitive adhesive having a thickness of 25 μm was used, and one side of the transparent glass substrate was not bonded to the protective film of the same polarizing plate as that used in Example 1 through this acrylic pressure-sensitive adhesive. Was bonded. Then, it processed in the autoclave of 50 degreeC for 20 minutes by the pressure of 5 kg / cm <2> (about 0.5 Mpa), and produced the optical laminated body.

Comparative Example 3

An optical laminate was produced in the same manner as in Example 1 (b) except that pure water was used instead of the polyvinyl alcohol adhesive composition.

[Evaluation test]

(a) endurance test

The durability of the optical laminated body produced by the said Example and the comparative example was evaluated by the following method.

When the heat resistance test stored for 100 hours under drying at a temperature of 80 ° C. was carried out, when the heat-resistant test carried out for 100 hours at a temperature of 60 ° C. and a relative humidity of 90% was performed, and the temperature was lowered to −35 ° C. from a state heated to 70 ° C. ( Iv), and the process of heating up at 70 ° C continuously is one cycle (two hours), and each of the cases where the heat shock test (denoted as "HS test" in the table) is repeated for 60 cycles. About the optical laminated body after a test, it observed visually. The results were classified according to the following criteria and summarized in Table 2.

(Evaluation Criteria of Heat, Moisture and Heat Shock Test)

(Double-circle): Appearance changes, such as lifting, peeling, and the crack of a polarizing film, are not seen at all.

○: Almost no change in appearance such as lifting, peeling, cracking of the polarizing film, and the like.

(Triangle | delta): Appearance changes, such as lifting, peeling, and the crack of a polarizing film, are notable a little.

X: Appearance changes, such as lifting, peeling, and the crack of a polarizing film, are remarkably seen.

(b) reworkability assessment

3 hours after bonding a polarizing plate to a glass substrate (in Examples 1-22 and Comparative Examples 1 and 3, 3 hours after leaving for 24 hours at normal temperature, 3 hours after completion of autoclave treatment in Comparative Example 2) In order to see whether a polarizing plate can be peeled from a glass substrate, the peeling test which peeled a polarizing plate from an adhesion test piece to a 180 degree direction (retracting and following a glass substrate surface) at a speed | rate of 300 mm / min was performed. . The results were classified according to the following criteria and summarized in Table 2.

(Evaluation standard of reworkability)

(Circle): It could peel.

X: The polarizing plate was broken and could not be peeled off.

The optical laminated bodies of Examples 1-22 are thin, and are excellent in durability and rework property. On the other hand, in the optical laminated body of the comparative example 1 using the aqueous solution of polyvinylpyrrolidone as an adhesive composition, the problem arose in the durability test. Moreover, in the optical laminated body of the comparative example 2 which used the acrylic adhesive for adhesion | attachment of glass and a polarizing plate, a problem occurred in heat shock resistance and rework resistance. Moreover, in the optical laminated body of the comparative example 3 which used pure water as an adhesive agent, the problem arose in heat resistance and heat shock resistance.

[Description of the code]

1: glass plate (liquid crystal cell substrate)

2: adhesive layer

3: plastic sheet

5: polarizer

6: polarizing film

7: transparent protective layer

8: resin layer

10, 11, 12: optical stack

Claims (12)

A glass plate and a plastic sheet are bonded together via an adhesive bond layer, and the adhesive layer is formed of an adhesive composition containing a polyvinyl alcohol-based resin. The optical laminate of claim 1, wherein the adhesive composition further contains a silane coupling agent. The optical laminate according to claim 1 or 2, wherein the adhesive composition further contains a crosslinking agent. The optical laminate according to claim 1 or 2, wherein the adhesive layer has a thickness of 5 µm or less. The optical laminate according to claim 1 or 2, wherein the glass plate is a liquid crystal cell substrate. The optical laminate according to claim 1 or 2, wherein the plastic sheet is a polarizing plate having a polarizing film in which a dichroic dye is adsorbed and oriented in a polyvinyl alcohol-based resin. The optical laminate according to claim 6, wherein the polarizing plate includes the polarizing film and a transparent protective layer formed on at least one surface thereof. The polarizing plate of claim 7, wherein the polarizing plate includes the polarizing film and a transparent protective layer formed on one surface thereof, and the polarizing film surface opposite to the transparent protective layer is directly bonded to the liquid crystal cell substrate through the adhesive layer. Optical laminate which is. 8. The liquid crystal cell according to claim 7, wherein the polarizing plate comprises a polarizing film, a transparent protective layer formed on one surface thereof, and a phase difference plate laminated on the other side of the polarizing film, and the phase difference plate side is connected to the liquid crystal cell through the adhesive layer. The optical laminated body bonded to the board | substrate. As a method of manufacturing an optical laminate in which a plastic sheet is bonded to a glass plate,
The said method is a formation process of the adhesive composition layer which provides the layer of the adhesive composition containing the aqueous solution containing polyvinyl alcohol-type resin in one or more of each bonding surface of a glass plate and a plastic sheet,
A bonding step of bonding the glass plate and the plastic sheet through a layer of the adhesive composition,
An inspection step of inspecting the bonded article obtained in the joining step and sending out the bonded article in which the defect is detected, out of the production line, and
Hardening process which hardens the layer of the adhesive composition which exists in the joined article which a defect was not detected through the said inspection process.
It is provided with. The method of claim 10, wherein the glass plate is a liquid crystal cell substrate, and the plastic sheet is a polarizing plate having a polarizing film in which a dichroic dye is adsorbed and oriented in a polyvinyl alcohol-based resin. The method according to claim 10 or 11, wherein the bonded article in which the defect is detected in the inspection step is configured to return the glass plate to the forming step of the adhesive composition layer after peeling off the plastic sheet.

Images