KR20100013337A - Adhesive sheet for optical film, process for production of the adhesive sheet, adhesive optical film, and image display device - Google Patents

Abstract

Disclosed is an adhesive sheet for an optical film, which comprises a mold release sheet and an adhesive layer formed on the mold release sheet, wherein the surface roughness (Ra) of the surface of the adhesive layer on the mold release sheet is 2 to 150 nm.The adhesive sheet can be produced by a production process comprising the steps of: applying an adhesive coating solution on a mold release sheet; and subjecting the adhesive coating solution to a first drying operation at a temperature of 30 to 80°C and an air flow rate of 0.5 to 15 m/second and a second drying operation at a temperature of 90 to 160°C and an air flow rate of 0.1 to 25 m/second to form an adhesive layer on the mold release sheet. When the adhesive sheet is applied to an image display device such as a liquid crystal display device, the occurrence of a trouble in visibility attributed to the adhesive layer can be reduced.

Description

Adhesive sheet for optical films, its manufacturing method, adhesive optical film, and image display apparatus {ADHESIVE SHEET FOR OPTICAL FILM, PROCESS FOR PRODUCTION OF THE ADHESIVE SHEET, ADHESIVE OPTICAL FILM, AND IMAGE DISPLAY DEVICE}

This invention relates to the adhesive sheet for optical films, and its manufacturing method. Moreover, it is related with the adhesive optical film using the said adhesive sheet for optical films. Furthermore, it is related with image display apparatuses, such as a liquid crystal display device, an organic electroluminescence display, a CRT, and a PDP using the said adhesive optical film. As said optical film, a polarizing plate, a retardation plate, an optical compensation film, a brightness improving film, what these are laminated | stacked, etc. are mentioned, for example.

Liquid crystal panels are used in liquid crystal displays in watches, mobile phones, PDAs, notebook computers, PC monitors, DVD players, TVs, and the like. Background Art In recent years, demands related to display characteristics such as brightness enhancement, high definition, and low reflection have increased in optical panels including liquid crystal panels. Moreover, the request | requirement about an external appearance also increases in the optical film used for an optical panel.

When attaching the said optical film to a liquid crystal cell, an adhesive is used normally. Moreover, in order for adhesion | attachment between an optical film, a liquid crystal cell, or an optical film to reduce the loss of light normally, each material is closely adhered using an adhesive. In such a case, since the adhesive has the advantage of not requiring a drying process in order to fix an optical film, the adhesive optical film previously formed as an adhesive layer in the one side of an optical film is generally used.

When the liquid crystal display device which attached the said optical film using the adhesive, especially the notebook and PC monitor, since the brightness improvement and the low reflection of the panel outermost surface are performed, when a liquid crystal display device is visually recognized in the inclination direction There exists a problem that the coating nonuniformity of an adhesive layer arises, and this may have a big influence on visibility.

About an adhesive layer, controlling coating thickness and surface roughness is proposed. For example, it is proposed to improve durability in a high temperature, high temperature and high humidity environment by making standard deviation small about the deviation of the thickness of the adhesive layer formed in a polarizing plate etc. (patent document 1). Moreover, forming an adhesive layer in the mold release base material which controlled the surface roughness of a mold release surface small, and transferring the said adhesive layer to a protective film, and forming the adhesive layer which controlled the surface roughness small on a protective film is carried out. It is proposed (patent document 2). However, even with the said patent document, the influence on the visibility by the nonuniformity of an adhesive layer was not improved.

Patent Document 1: Japanese Patent Application Laid-Open No. 9-90125

Patent Document 2: Japanese Unexamined Patent Publication No. 2005-306996

Disclosure of Invention

Problems to be Solved by the Invention

When this invention is applied to image display apparatuses, such as a liquid crystal display device, it aims at providing the adhesive sheet for optical films and its manufacturing method which can reduce the problem of visibility which concerns on an adhesive layer.

Moreover, an object of this invention is to provide the adhesive optical film using the said adhesive sheet for optical films. Moreover, an object of this invention is to provide the image display apparatus using the said adhesive optical film.

Means to solve the problem

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, it discovered that the said objective can be achieved by the following adhesive sheet for optical films, and its manufacturing method, and came to complete this invention.

That is, this invention is an adhesive sheet for optical films which has an adhesive layer on a release sheet,

Surface roughness Ra of the adhesive layer surface on a release sheet is 2-150 nm, It is related with the adhesive sheet for optical films.

Moreover, this invention is a process of coating an adhesive coating liquid on a release sheet,

An adhesive layer is formed by performing the said 1st drying process of the temperature of 30-80 degreeC, the wind speed of 0.5-15 m / sec, and the 2nd drying process of the temperature of 90-160 degreeC, and the wind speed of 0.1-25 m / sec to the said adhesive coating liquid. It has a process to do, It is related with the manufacturing method of the adhesive sheet for optical films.

Moreover, this invention is an adhesive optical film which stuck an optical film to the adhesive layer surface of the adhesive sheet for optical films which has an adhesive layer on a release sheet,

The adhesive sheet for optical films is an adhesive sheet for optical films of Claim 1, and the optical film was stuck to the adhesive layer surface of surface roughness (Ra) 2-150 nm, It is related with the adhesive optical film characterized by the above-mentioned.

Moreover, this invention relates to the image display apparatus which used at least one adhesive optical film from which the release sheet peeled from the said adhesive optical film.

Effects of the Invention

The inventors have found that the surface roughness Ra of the adhesive to adhere to the optical film, in particular the surface roughness Ra in the vertical direction (orthogonal direction) to the long direction, greatly influences the visibility. In the adhesive sheet for optical films of this invention, the surface roughness (Ra) of the surface of the adhesive layer formed on the release sheet is controlled to 2-150 nm, and the adhesive layer is formed without coating nonuniformity. In the pressure-sensitive adhesive optical film produced by attaching the pressure-sensitive adhesive sheet for optical film of the present invention to an optical film, the pressure-sensitive adhesive layer surface having the surface roughness is attached to the optical film. As mentioned above, since the adhesive layer surface of the adhesive sheet for optical films is formed without nonuniformity, the fall of the visibility by an adhesive layer is suppressed, and the visibility of a liquid crystal display device, especially the visibility in a diagonal direction can be improved. .

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of an example of the adhesive sheet for optical films of this invention.

2 is a cross-sectional view of an example of the pressure-sensitive adhesive optical film of the present invention.

Explanation of the sign

1 release sheet

2 pressure sensitive adhesive layer

2a surface roughness (Ra) of the pressure-sensitive adhesive layer surface of 2 to 150 nm

3 optical film

Invention  Conduct  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated, referring drawings. 1: is sectional drawing of the adhesive sheet A for optical films of this invention, and has the adhesive layer 2 on the release sheet 1. The surface roughness Ra of the adhesive layer surface 2a is 2-150 nm. FIG. 2: is the adhesive optical film of this invention, and the adhesive layer surface 2a of the adhesive layer 2 of the adhesive sheet A for optical films, and the optical film 3 are affixed. When applying the said adhesive optical film to image display apparatuses, such as a liquid crystal display device, the release sheet 1 is peeled off and it is with the adhesive layer surface 2b of the adhesive layer 2; and the adhesive layer surface 2a. Opposite sides) are attached to various materials.

In the adhesive sheet A for optical films of this invention, the surface roughness Ra of the adhesive layer surface 2a is 2-150 nm. It is preferable that the said surface roughness Ra is 10-140 nm, Furthermore, it is preferable that it is 20-120 nm, Furthermore, it is 30-100 nm. When the said surface roughness Ra exceeds 180 nm, the nonuniformity of an adhesive layer becomes remarkable and adversely affects visibility. On the other hand, when the said surface roughness Ra is less than 2 nm, adhesiveness with an optical film falls or it has a remarkably bad influence on productivity.

The release sheet has at least a film substrate. As a constituent material of a film base material, synthetic resin films, such as polyolefin resin, such as paper, polyethylene, and a polypropylene, polyester-based resins, such as polyethylene terephthalate and polyethylene naphthalate, a rubber sheet, paper, cloth, a nonwoven fabric, a net, Suitable foils, such as a foam sheet, metal foil, and those laminated bodies, etc. are mentioned. Among these, the film base material is preferably polyethylene resin, polyolefin resin, or paper. The thickness of a film base material is 10-125 micrometers normally, It is preferable that it is 20-100 micrometers, It is more preferable that it is 30-80 micrometers.

The film base material of a release sheet can form a peeling layer and / or an anti-migration layer of an oligomer in the side formed in an adhesive layer.

As said mold release layer, it can form with appropriate peeling agents, such as a silicone type, a long chain alkyl type, a fluorine type, and molybdenum sulfide. The thickness of a mold release layer can be set suitably from a mold release effect viewpoint. In general, the thickness is preferably 20 µm or less, more preferably in the range of 0.01 to 10 µm, and particularly preferably in the range of 0.1 to 5 µm in view of handling properties such as flexibility. It does not specifically limit as a formation method of a release layer, For example, a coating method, a spray method, a spin coat method, an in-line coat method, etc. are used. Moreover, a vacuum vapor deposition method, sputtering method, ion plating method, spray pyrolysis method, chemical plating method, electroplating method, etc. can also be used.

When forming the said transition prevention layer with a release layer, it is preferable to form between a release layer and the film base material of a release sheet. As said migration prevention layer, it can form with an appropriate material for preventing migration of the transition component in the base film (for example, polyester film) of a release sheet, especially the low molecular weight oligomer component of polyester. As a formation material of a migration prevention layer, an inorganic substance, organic substance, or those composite materials can be used. The thickness of a migration prevention layer can be suitably set in the range of 0.01-20 micrometers.

It does not specifically limit as a formation method of a migration prevention layer, The method similar to the formation method of a release layer can be employ | adopted. In the coating method, the spray method, the spin coating method, and the inline coating method, ionizing radiation curable resins such as acrylic resins, urethane resins, melamine resins, epoxy resins, and the like are mixed with aluminum oxide, silicon dioxide, mica and the like. You can use one. In the case of using the vacuum deposition method, the sputtering method, the ion plating method, the spray pyrolysis method, the chemical plating method or the electroplating method, gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, cobalt or tin or The other metal compound which consists of metal oxides, iodide steel, etc. which consist of these alloys etc. can be used.

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer is not particularly limited, and various pressure-sensitive adhesives such as rubber pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, and silicone pressure-sensitive adhesives can be used. Acrylic pressure-sensitive adhesives having colorless transparency and good adhesion to liquid crystal cells are generally used. Used.

The acrylic pressure sensitive adhesive has an acrylic polymer having a monomer unit of alkyl (meth) acrylate as a main skeleton as a base polymer. In addition, (meth) acrylate refers to an acrylate and / or methacrylate, and has the same meaning as the (meth) of this invention. The carbon number of the alkyl group of the alkyl (meth) acrylate which comprises the main skeleton of an acryl-type polymer is about 1-14, and as a specific example of an alkyl (meth) acrylate, methyl (meth) acrylate and ethyl (meth) acryl Rate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) Acrylate, stearyl (meth) acrylate, etc. can be illustrated, These can be used individually or in combination. Among these, alkyl (meth) acrylates having 1 to 9 carbon atoms of the alkyl group are preferable.

In the said acryl-type polymer, in order to improve adhesiveness and heat resistance, it can introduce | transduce by copolymerization of 1 or more types of various monomers. As a specific example of such a copolymerization monomer, a carboxyl group-containing monomer, a hydroxyl-containing monomer, a nitrogen-containing monomer (including a heterocyclic monomer), an aromatic containing monomer, etc. are mentioned.

Carboxyl group containing monomers, For example, acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, etc. are mentioned. Among these, acrylic acid and methacrylic acid are preferable.

As a hydroxyl-containing monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) -methylacrylate, etc. are mentioned. Can be.

Moreover, as a nitrogen containing monomer, For example, maleimide, N-cyclohexyl maleimide, N-phenyl maleimide; N-acryloyl morpholine; (Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methyl (meth) acrylamide, N-butyl (N-substituted) amide monomers such as (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, and N-methylolpropane (meth) acrylamide; Amino ethyl (meth) acrylate, aminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, 3- (3-pyridylyl) propyl (meth) acrylate (Meth) acrylic-acid alkylaminoalkyl type monomers, such as these; Alkoxy alkyl (meth) acrylate monomers, such as (meth) acrylic-acid methoxyethyl and (meth) acrylate ethoxyethyl; N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, N Succinimide type monomers, such as acryloyl morpholine, etc. are mentioned as a monomer example for the purpose of modification.

As an aromatic containing monomer, benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, etc. are mentioned, for example.

In addition to the said monomer, Acid anhydride group containing monomers, such as maleic anhydride and itaconic anhydride; Caprolactone adducts of acrylic acid; Sulfonic acid group containing styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamide propanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxy naphthalene sulfonic acid, etc. Monomers; Phosphoric acid group containing monomers, such as 2-hydroxyethyl acryloyl phosphate, etc. are mentioned.

-메틸스티렌, N-비닐카프로락탐 등의 비닐계 모노머 ; 아크릴로니트릴, 메타크릴로니트릴 등의 시아노아크릴레이트계 모노머 ; (메타)아크릴산글리시딜 등의 에폭시 기 함유 아크릴계 모노머 ; (메타)아크릴산폴리에틸렌글리콜, (메타)아크릴산폴리프로필렌글리콜, (메타)아크릴산메톡시에틸렌글리콜, (메타)아크릴산메톡시폴리프로필렌글리콜 등의 글리콜계 아크릴에스테르 모노머 ; (메타)아크릴산테트라히드로 푸르푸릴, 불소(메타)아크릴레이트, 실리콘(메타)아크릴레이트나 2-메톡시에틸아크릴레이트 등의 아크릴산에스테르계 모노머 등도 사용할 수 있다. In addition, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole , Vinyl morpholine, N-vinylcarboxylic acid amides, styrene,

Vinyl monomers such as methyl styrene and N-vinyl caprolactam; Cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; Epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; Glycol-based acrylic ester monomers such as polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, and methoxypolypropylene glycol (meth) acrylate; Acrylic acid ester type monomers, such as (meth) acrylic acid tetrahydrofurfuryl, a fluorine (meth) acrylate, silicone (meth) acrylate, and 2-methoxyethyl acrylate, can also be used.

Among these, a hydroxyl group containing monomer is used preferably from the point which the reactivity with a crosslinking agent is favorable. Moreover, in terms of adhesiveness and adhesion durability, carboxyl group-containing monomers such as acrylic acid are preferably used.

Although the ratio of the said copolymerization monomer in an acryl-type polymer is not specifically limited, In a weight ratio, it is 50 weight% or less. Preferably it is 0.1-10 weight%, More preferably, it is 0.5-8 weight%, More preferably, it is 1-6 weight%.

The average molecular weight of the acrylic polymer is not particularly limited, but the weight average molecular weight is preferably about 300,000 to 2.5 million. Manufacture of the said acrylic polymer can be manufactured by various well-known methods, For example, radical polymerization methods, such as a bulk polymerization method, a solution polymerization method, and suspension polymerization method, can be selected suitably. As a radical polymerization initiator, various well-known things, such as an azo system and a peracid (meth) type, can be used. Reaction temperature is about 50-80 degreeC normally, and reaction time is 1 to 8 hours. Moreover, the solution polymerization method is preferable also in the said manufacturing method, and ethyl acetate, toluene, etc. are generally used as a solvent of an acryl-type polymer.

The adhesive which forms the adhesive layer of this invention can contain a crosslinking agent in addition to a base polymer. By a crosslinking agent, adhesiveness and durability with an optical film can be improved, and reliability at high temperature and shape maintenance of an adhesive itself can be aimed at. When the base polymer is an acrylic polymer, an isocyanate type, an epoxy type, a peroxide type, a metal chelate type, an oxazoline type, or the like can be appropriately used as the crosslinking agent. These crosslinking agents can be used 1 type or in combination of 2 or more type.

An isocyanate compound is used for an isocyanate type crosslinking agent. As an isocyanate compound, isocyanate, such as tolylene diisocyanate, chlorphenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. Adduct type isocyanate compound which added the monomer and these isocyanate monomers with trimethylol propane etc .; Urethane prepolymer type isocyanate etc. which addition-reacted isocyanurate compound, a biuret type compound, a well-known polyether polyol, polyester polyol, an acryl polyol, polybutadiene polyol, polyisoprene polyol, etc. are mentioned.

As an epoxy type crosslinking agent, the bisphenol A epichlorohydrin type epoxy resin is mentioned, for example. Moreover, as an epoxy type crosslinking agent, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycid Dilether, trimethylolpropanetriglycidylether, diglycidylaniline, N, N, N ', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglyl) Cydylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, mN, N- diglycidylaminophenyl glycidyl ether, N , N-diglycidyl toluidine, N, N-diglycidyl aniline, and the like.

As the peroxide crosslinking agent, various peroxides are used. As the peroxide, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxy neodecanoate, t- Hexyl peroxy pivalate, t-butyl peroxy pivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxyisobutylate, 1,1 And 3,3-tetramethylbutyl peroxy 2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxy isobutylate and the like. Among these, di (4-t-butylcyclohexyl) peroxydicarbonate, dilauroyl peroxide, and dibenzoyl peroxide, which are particularly excellent in crosslinking reaction efficiency, are preferably used.

The usage-amount of a crosslinking agent is 10 weight part or less with respect to 100 weight part of acrylic polymers, Preferably it is 0.01-5 weight part, More preferably, it is 0.02-3 weight part. When the use ratio of a crosslinking agent exceeds 10 weight part, crosslinking advances too much and it is unpreferable in that there exists a possibility that adhesiveness may fall.

Moreover, the said adhesive contains a filler, a pigment, a coloring agent, a filler, antioxidant, a ultraviolet absorber, a silane coupling agent, etc. which consist of a tackifier, a plasticizer, glass fiber, glass beads, a metal powder, other inorganic powder etc. as needed. Moreover, various additives can also be used suitably in the range which does not deviate from the objective of this invention. Moreover, it is good also as an adhesive layer etc. which contain microparticles | fine-particles and show light diffusivity.

It is preferable to mix | blend a silane coupling agent among the said additives. As a silane coupling agent, Silicon compounds which have a double bond, such as vinyl trimethoxysilane; Silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane and N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane; 3-chloropropyltrimethoxysilane; (Meth) acryl group containing silane coupling agents, such as acetoacetyl group containing trimethoxysilane, 3-acryloxypropyl trimethoxysilane, and 3-methacryloxypropyl triethoxysilane; Isocyanate group containing silane coupling agents, such as 3-isocyanate propyl triethoxysilane, etc. are mentioned. A silane coupling agent can provide the effect which suppresses peeling in durability, especially a humidification environment. The usage-amount of a silane coupling agent is 1 weight part or less with respect to 100 weight part of base polymers, Furthermore, it is 0.01-1 weight part, Preferably it is 0.02-0.6 weight part.

The adhesive sheet for optical films of this invention can be obtained by performing the process of coating an adhesive coating liquid on a release sheet, and the process of forming an adhesive layer with the said adhesive coating liquid.

When performing the said coating process, the adhesive coating liquid is prepared. The pressure-sensitive adhesive coating liquid may be either a solution or a dispersion liquid. In the case of a solution, as a solvent, aromatic solvents, such as toluene, and ester solvents, such as ethyl acetate, are used, for example. The concentration of the pressure-sensitive adhesive coating liquid is usually about 2 to 80% by weight, preferably 5 to 40% by weight, more preferably 7.5 to 20% by weight.

The coating method of the adhesive coating liquid on a release sheet is not specifically limited, For example, Die coating methods, such as a closed edge die and a slot die; Roll coating methods such as reverse coating and gravure coating, spin coating, screen coating, fountain coating, dipping, spraying and the like can be employed.

In the coating process of the said adhesive coating liquid, although the dry thickness of the adhesive layer formed can be adjusted suitably, it is about 1-40 micrometers normally, 5-30 micrometers is preferable, and also 10-25 micrometers is preferable.

Next, the said adhesive coating liquid coated on the release sheet is dried, and the adhesive layer whose surface roughness Ra is 2-150 nm is formed. Formation of the said adhesive layer, for example, after performing the 1st drying process of temperature 30-80 degreeC and wind speed 0.5-15 m / sec, performs the 2nd drying process of temperature 90-160 degreeC and wind speed 0.1-25 m / sec. It can carry out by implementing.

The 1st drying process evaporates the solvent of an adhesive coating liquid, and forms the adhesive layer surface whose surface roughness Ra is 2-150 nm. Next, by the 2nd drying process, the adhesive layer whose surface roughness Ra formed by the 1st drying process is 2-150 nm is hardened | cured (solidified;), and an adhesive layer is formed.

The temperature of a 1st drying process is 30-80 degreeC, 40-70 degreeC is preferable and 40-60 degreeC is more preferable. If the said temperature is less than 30 degreeC, drying of a solvent takes too long and it is unpreferable from a productivity viewpoint. On the other hand, when temperature exceeds 80 degreeC, drying will advance too much and it will become impossible to control the surface of an adhesive layer by said surface roughness Ra. Moreover, the wind speed is 0.5-15 m / sec, 0.5-10 m / sec is preferable and 1-5 m / sec is more preferable. If the wind speed is less than 0.5 m / sec, it takes too long to dry the solvent, which is not preferable in terms of productivity. On the other hand, when the wind speed is larger than 15 m / sec, drying proceeds too much and the surface of the pressure-sensitive adhesive layer cannot be controlled by the surface roughness Ra. The treatment time in the first drying step is about 10 seconds to 30 minutes, preferably 30 seconds to 20 minutes, and more preferably 45 seconds to 10 minutes. In addition, the processing time in a 1st drying process is controlled so that the surface of an adhesive layer may be said surface roughness Ra in consideration of the relationship with temperature and wind speed.

The temperature of a 2nd drying process is 90-160 degreeC, 130-160 degreeC is preferable and 135-155 degreeC is more preferable. When the said temperature is less than 90 degreeC, drying of a solvent takes too long and is not preferable from a productivity viewpoint. On the other hand, when temperature exceeds 160 degreeC, it is colored by an adhesive and it is not preferable. Moreover, the wind speed is 0.1-25 m / sec, 1-23 m / sec is preferable and 5-20 m / sec is more preferable. If the wind speed is less than 0.1 m / sec, it takes too long to dry the solvent, which is not preferable in terms of productivity. On the other hand, when the wind speed is larger than 25 m / sec, it adversely affects the running property of the film and is not preferable. The treatment time in the second drying step is about 10 seconds to 20 minutes, preferably 20 seconds to 10 minutes, and more preferably 30 seconds to 3 minutes. In addition, the processing time in a 2nd drying process is controlled to harden | cure (solidify) an adhesive layer in consideration of the relationship with temperature and wind speed.

In the said 1st drying process and a 2nd drying process, as a means of controlling temperature to the said range, an oven, a warm air fan, a heating roll, a far-infrared heater etc. can be used, for example. Moreover, in the said 1st drying process and the 2nd drying process, as a blowing means which controls a wind speed in the said range, it can implement by a counter flow type. The distance from the said blowing means is about 10-100 cm, Preferably it is 10-50 cm. The wind speed can be measured by a miniben type digital anemometer. Wind speed measurement measured the wind speed of the 3 cm position below the blowing nozzle on the adhesive coating liquid coated on the release sheet using the anemometer. The anemometer was used the anemometer MODEL1560 / SYSTEM6243 by Nippon Kanomax Co., Ltd. product.

The adhesive sheet for optical films of this invention can be attached to an optical film, and can be used as an adhesive optical film. By the said attachment, the adhesive layer of the adhesive sheet for optical films is transferred to an optical film. When using the said adhesive optical film for an image display apparatus, the adhesive sheet which peeled a release sheet and exposed was attached to a liquid crystal cell or another member, and is used. It is especially preferable to make it adhere to display parts, such as a liquid crystal cell.

As an optical film, what is used for formation of image display apparatuses, such as a liquid crystal display device, is used, The kind in particular is not restrict | limited. For example, a polarizing plate is mentioned as an optical film. As for the polarizing plate, one having a transparent protective film is generally used on one side or both sides of the polarizer.

As a polarizer, dichroic substances, such as iodine and a dichroic dye, are used for hydrophilic polymer films, such as a polyvinyl alcohol-type film, a partially formalized polyvinyl alcohol-type film, and an ethylene-vinyl acetate copolymerization system partial saponification film, for example. Polyene oriented films, such as the thing uniaxially stretched by adsorption, the dehydration process of polyvinyl alcohol, and the dehydrochlorination process of polyvinyl chloride, etc. are mentioned. Among these, the polarizer obtained from dichroic substances, such as a polyvinyl alcohol-type film and iodine, is preferable. Although the thickness in particular of these polarizers is not restrict | limited, Usually, it is about 5-80 micrometers.

The polarizer which uniaxially stretched the polyvinyl alcohol-type film by iodine, for example, can be manufactured by dyeing by dipping polyvinyl alcohol in the aqueous solution of iodine, and extending | stretching 3 to 7 times the original length. It can also be immersed in aqueous solution, such as a boric acid and potassium iodide, as needed. If necessary, the polyvinyl alcohol-based film may be dipped in water and washed with water before dyeing. In addition to washing the polyvinyl alcohol-based film with water, the contamination of the polyvinyl alcohol-based film with the anti-blocking agent can be washed, and the polyvinyl alcohol-based film is swollen to prevent irregularities such as staining. Stretching may be performed after dyeing with iodine, or may be performed while dyeing, or may be dyed with iodine after stretching. It can extend | stretch in aqueous solution, such as a boric acid and potassium iodide, or in a water bath. The stretching method is not particularly limited and any method of wet or dry may be employed.

As a material which comprises a transparent protective film, the thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. is used, for example. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and (meth) acryl Resins, cyclic polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. In addition, although a transparent protective film is affixed on one side of a polarizer by an adhesive bond layer, thermosetting resin or ultraviolet curable resins, such as (meth) acrylic-type, a urethane type, an acrylurethane type, an epoxy type, a silicone type, are used as a transparent protective film on the other side. Can be used. One or more types of arbitrary appropriate additives may be contained in the transparent protective film. As an additive, a ultraviolet absorber, antioxidant, a lubricating agent, a plasticizer, a mold release agent, a coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a coloring agent, etc. are mentioned, for example. Content of the said thermoplastic resin in a transparent protective film becomes like this. Preferably it is 50-100 weight%, More preferably, it is 50-99 weight%, More preferably, it is 60-98 weight%, Especially preferably, it is 70-97 weight% . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has may not be fully expressed.

Moreover, as a transparent protective film, the polymer film of Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007), for example, the thermoplastic resin which has a substituted and / or unsubstituted imide group in (A) side chain, (B) The resin composition containing the thermoplastic resin which has a substituted and / or unsubstituted phenyl and a nitrile group in a side chain is mentioned. As a specific example, the film of the resin composition containing the alternating copolymer which consists of isobutylene and N-methyl maleimide, and an acrylonitrile styrene copolymer is mentioned. As a film, the film which consists of a mixed extrudate of a resin composition, etc. can be used. Since these films have a small phase difference and a small photoelastic coefficient, problems such as unevenness due to deformation of the polarizing plate can be solved, and since the moisture permeability is small, the humidification durability is excellent.

Although the thickness of a transparent protective film can be suitably determined, it is about 1-500 micrometers generally in terms of workability, thinness, etc., such as strength and handleability. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable. A transparent protective film is especially preferable when it is 5-150 micrometers.

In addition, when forming a polarizer protective film on both sides of a polarizer, the material of a polarizer protective film may use the transparent protective film which consists of the same polymer material in the front and back, or may use the transparent protective film which consists of different polymer materials, etc. do.

As the transparent protective film of the present invention, it is preferable to use at least one selected from a cellulose resin, a polycarbonate resin, a cyclic polyolefin resin, and a (meth) acrylic resin. The adhesive agent for electron beam curable polarizing plates of this invention shows preferable adhesiveness with respect to the said various transparent protective films. In particular, the adhesive agent for electron beam hardening type polarizing plates of this invention shows favorable adhesiveness also to the acrylic resin which was difficult to satisfy adhesiveness.

The cellulose resin is an ester of cellulose and a fatty acid. Specific examples of such cellulose ester-based resins include cellulose triacetate, cellulose diacetate, cellulose tripropionate, cellulose dipropionate, and the like. Among these, cellulose triacetate is particularly preferable. Cellulose triacetate is commercially available in many products, and is advantageous in terms of availability and cost. As an example of a cellulose triacetate commercial item, a brand name "UV-50", "UV-80", "SH-80", "TD-80U", "TD-TAC" and "UZ-TAC" of the Fujifilm company make And "KC series" manufactured by Konica Corporation. Generally, in these cellulose triacetate, in-plane phase difference Re is almost zero, but thickness direction retardation Rth has about 60 nm.

Moreover, the cellulose resin film with a small thickness direction retardation is obtained by processing the said cellulose resin, for example. For example, base films, such as polyethylene terephthalate, polypropylene, and stainless steel which coated solvents, such as cyclopentanone and methyl ethyl ketone, are affixed on a general cellulose film, and it heat-drys (for example, 3 at 80-150 degreeC) To 10 minutes), and then the base film is peeled off; A solution obtained by dissolving norbornene-based resin and (meth) acrylic resin in a solvent such as cyclopentanone and methyl ethyl ketone is coated on a common cellulose resin film and dried by heating (for example, at about 80 to 150 ° C. for about 3 to 10 minutes). After making it, the method of peeling a coating film, etc. are mentioned.

Moreover, as a cellulose resin film with a small thickness direction retardation, the fatty acid cellulose resin film which controlled fat substitution degree can be used. In the triacetyl cellulose generally used, although acetic acid substitution degree is about 2.8, Preferably, Rth can be made small by controlling acetic acid substitution degree to 1.8-2.7. Rth can be controlled small by adding plasticizers, such as dibutyl phthalate, p-toluenesulfonanilide, and acetyl triethyl citrate, to the said fatty acid substituted cellulose resin. The addition amount of a plasticizer is 40 weight part or less with respect to 100 weight part of fatty acid cellulose resins, More preferably, it is 1-20 weight part, More preferably, it is 1-15 weight part.

-올레핀과 그 공중합체 (대표적으로는 랜덤 공중합체), 및, 이들을 불포화 카르복실산이나 그 유도체로 변성한 그래프트 중합체, 그리고, 그들의 수소화물 등을 들 수 있다. 고리형 올레핀의 구체예로는, 노르보르넨계 모노머를 들 수 있다. As a specific example of cyclic polyolefin resin, Preferably it is norbornene-type resin. Cyclic olefin resin is a general term of resin superposed | polymerized using a cyclic olefin as a polymerization unit, For example, Unexamined-Japanese-Patent No. 1-240517, Unexamined-Japanese-Patent No. 3-14882, Unexamined-Japanese-Patent No. The resin described in Unexamined-Japanese-Patent No. 3-122137 etc. is mentioned. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, cyclic olefins, ethylene, propylene, and the like.

-An olefin, its copolymer (typically a random copolymer), the graft polymer which modified | denatured these with unsaturated carboxylic acid, its derivatives, these hydrides, etc. are mentioned. As a specific example of a cyclic olefin, a norbornene-type monomer is mentioned.

Various products are commercially available as cyclic polyolefin resin. As a specific example, brand name "Xeonex", "Zenoa" of Nippon Xeon Corporation, brand name "Aton" of JSR Corporation, brand name "Topas" of TICONA company, brand name "APEL" of Mitsui Chemicals, Inc. are mentioned Can be.

As (meth) acrylic-type resin, Tg (glass transition temperature) becomes like this. Preferably it is 115 degreeC or more, More preferably, it is 120 degreeC or more, More preferably, it is 125 degreeC or more, Especially preferably, it is 130 degreeC or more. When Tg is 115 degreeC or more, it can become the thing excellent in the durability of a polarizing plate. Although the upper limit of Tg of the said (meth) acrylic-type resin is not specifically limited, From a viewpoint of moldability etc., Preferably it is 170 degrees C or less. From (meth) acrylic-type resin, the film whose in-plane phase difference Re and thickness direction phase difference Rth are almost zero can be obtained.

As (meth) acrylic-type resin, arbitrary appropriate (meth) acrylic-type resin can be employ | adopted within the range which does not impair the effect of this invention. For example, poly (meth) acrylic acid ester, such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-methyl ester -(Meth) acrylic acid copolymer, (meth) acrylic acid methyl-styrene copolymer (MS resin etc.), the polymer which has an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl copolymer, methacrylic acid Methyl- (meth) acrylic acid norbornyl copolymer, etc.) is mentioned. Preferably, poly (meth) acrylic-acid C1-6 alkyl, such as poly poly (meth) acrylate, is mentioned. More preferably, methyl methacrylate type resin which has methyl methacrylate as a main component (50-100 weight%, Preferably 70-100 weight%) is mentioned.

As a specific example of (meth) acrylic-type resin, For example, the (meth) acrylic-type which has a ring structure in the molecule | numerator of Mitsubishi Rayon Co., Ltd. product Acripet VH, Acripet VRL20A, Unexamined-Japanese-Patent No. 2004-70296, for example. The high Tg (meth) acrylic resin system obtained by resin, intramolecular crosslinking, and intramolecular cyclization reaction is mentioned.

As (meth) acrylic-type resin, (meth) acrylic-type resin which has a lactone ring structure can also be used. It is because it has high mechanical strength by high heat resistance, high transparency, and biaxial stretching.

As (meth) acrylic-type resin which has a lactone ring structure, Unexamined-Japanese-Patent No. 2000-230016, Unexamined-Japanese-Patent No. 2001-151814, Unexamined-Japanese-Patent No. 2002-120326, Unexamined-Japanese-Patent No. 2002-254544, Unexamined Japan (Meth) acrylic-type resin which has a lactone ring structure as described in patent publication 2005-146084 etc. is mentioned.

(Meth) acrylic-type resin which has a lactone ring structure, Preferably it has the structure of the ring represented by the following general formula (Formula 1).

[Formula 1]

In formula, R <^1> , R <^2> and R <^3> respectively independently represent a hydrogen atom or the organic residue of 1-20 carbon atoms. In addition, the organic residue may contain the oxygen atom.

The content ratio of the lactone ring structure represented by General Formula (Formula 1) in the (meth) acrylic resin structure having a lactone ring structure is preferably 5 to 90% by weight, more preferably 10 to 70% by weight, still more preferably Is 10 to 60% by weight, particularly preferably 10 to 50% by weight. When the content rate of the lactone ring structure represented by General formula (Formula 1) in the (meth) acrylic-type resin structure which has a lactone ring structure is less than 5 weight%, there exists a possibility that heat resistance, solvent resistance, and surface hardness may become inadequate. When the content rate of the lactone ring structure represented by General formula (Formula 1) in the (meth) acrylic-type resin structure which has a lactone ring structure is more than 90 weight%, there exists a possibility that molding workability may become inadequate.

As for (meth) acrylic-type resin which has a lactone ring structure, mass mean molecular weight (it may be called a weight average molecular weight) becomes like this. Preferably it is 1000-2 million, More preferably, it is 5000-1000000, More preferably, it is 10000-50000 Especially preferably, they are 50000-500000. If the mass average molecular weight is out of the above range, it is not preferable in view of moldability.

As for (meth) acrylic-type resin which has a lactone ring structure, Tg becomes like this. Preferably it is 115 degreeC or more, More preferably, it is 120 degreeC or more, More preferably, it is 125 degreeC or more, Especially preferably, it is 130 degreeC or more. Since Tg is 115 degreeC or more, when it is attached to a polarizing plate as a transparent protective film, it becomes excellent in durability, for example. Although the upper limit of Tg of (meth) acrylic-type resin which has the said lactone ring structure is not specifically limited, From a viewpoint of moldability etc., Preferably it is 170 degrees C or less.

As for the (meth) acrylic-type resin which has a lactone ring structure, the higher the total light transmittance measured by the method according to ASTM-D-1003 of the molded article obtained by injection molding, the higher it is, Preferably it is 85% or more, More preferably Preferably at least 88%, more preferably at least 90%. If the total light transmittance is less than 85% on the basis of transparency, there is a fear that the transparency is lowered.

As for the said transparent protective film, a thing whose frontal phase difference is less than 40 nm and thickness direction phase difference is less than 80 nm is normally used. Front phase difference Re is represented by Re = (nx-ny) xd. Thickness direction retardation Rth is represented by Rth = (nx-nz) xd. In addition, Nz coefficient is represented by Nz = (nx-nz) / (nx-ny). [However, the refractive indices in the slow axis direction, the fast axis direction, and the thickness direction of the film are nx, ny, and nz, respectively, and d (nm) is the thickness of the film. The slow axis direction is set to the direction of the maximum refractive index in the film plane.] In addition, the transparent protective film preferably has no coloring as much as possible. The protective film whose retardation value of the thickness direction is -90 nm-+75 nm is used preferably. By using the thing whose phase difference value Rth of such a thickness direction is -90 nm-+75 nm, coloring (optical coloring) of the polarizing plate resulting from a transparent protective film can be almost eliminated. The thickness direction retardation value Rth is more preferably -80 nm to +60 nm, particularly preferably -70 nm to +45 nm.

On the other hand, as the transparent protective film, a phase difference plate having a phase difference of 40 nm or more and / or a thickness direction phase difference of 80 nm or more can be used. The front phase difference is usually in a range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in a range of 80 to 300 nm. When using a retardation plate as a transparent protective film, since the said retardation plate also functions as a transparent protective film, thickness can be aimed at.

As a retardation plate, the birefringent film formed by carrying out uniaxial or biaxial stretching process of a polymeric material, the orientation film of a liquid crystal polymer, the thing which supported the orientation layer of a liquid crystal polymer with a film, etc. are mentioned. Although the thickness of a retardation plate is not specifically limited, either, About 20-150 micrometers is common.

Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, Polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyphenylene sulfide, polyphenylene oxide, polyallyl sulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose resin, cyclic polyolefin resin ( Norbornene-based resins), or binary or ternary various copolymers thereof, graft copolymers, blends, and the like. These polymeric raw materials become an orientation substance (stretched film) by extending | stretching etc.

As a liquid crystal polymer, various things, such as the main chain type and side chain type, in which the conjugated linear atomic group (mesogen) which gives liquid crystal aligning property were introduce | transduced into the main chain and side chain of a polymer, etc. are mentioned, for example. . As a specific example of a principal chain type liquid crystal polymer, the nematic oriented polyester-type liquid crystalline polymer, a discotic polymer, a cholesteric polymer, etc. of the structure which couple | bonded mesogenic groups in the spacer part which gives flexibility is mentioned, for example. Can be. As a specific example of a side chain type liquid crystal polymer, a polysiloxane, polyacrylate, polymethacrylate, or polymalonate is used as a main chain skeleton, and the side chain is a nematic orientation imparting agent via a spacer part which consists of a conjugated atomic group. The thing which has the mesogenic part which consists of para substituted cyclic compound units, etc. are mentioned. These liquid crystal polymers, for example, by developing a liquid crystalline polymer solution on an orientation treatment surface such as a rubbing treatment of a thin film surface such as polyimide or polyvinyl alcohol formed on a glass plate, or a vapor deposition of silicon oxide By heat treatment.

The retardation plate may have a suitable retardation according to the purpose of use, for example, for the purpose of compensating coloring or vision due to birefringence of various wavelength plates and liquid crystal layers, or by laminating two or more kinds of retardation plates. The thing which controlled optical characteristics, such as a phase difference, may be sufficient.

The phase difference plate satisfies the relationship of nx = ny> nz, nx> ny> nz, nx> ny = nz, nx> nz> ny, nz = nx> ny, nz> nx> ny, nz> nx = ny It is selected and used according to various uses. In addition, ny = nz means not only the case where ny and nz are exactly the same, but also the case where ny and nz are substantially the same.

For example, in the retardation plate which satisfy | fills nx> ny> nz, it is preferable to use the thing which satisfy | fills 40-100 nm, 100-320 nm of thickness direction retardations, and 1.8-4.5 of Nz coefficients in a front phase difference. For example, in the retardation plate (positive A plate) which satisfies nx> ny = nz, it is preferable to use the thing whose front retardation satisfy | fills 100-200 nm. For example, in the retardation plate (negative A plate) which satisfies nz = nx> ny, it is preferable to use the thing whose front retardation satisfy | fills 100-200 nm. For example, in the retardation plate which satisfies nx> nz> ny, it is preferable to use the thing whose front retardation is 150-300 nm and Nz coefficient exceeding 0 -0.7. As described above, for example, one that satisfies nx = ny> nz, nz> nx> ny, or nz> nx = ny can be used.

A transparent protective film can be suitably selected according to the liquid crystal display device applied. For example, in the case of VA (including vertical alignment, MVA, and PVA), it is preferable that the transparent protective film on at least one side (cell side) of the polarizing plate has a phase difference. As a specific phase difference, it is preferable that it is the range of Re = 0-240 nm and Rth = 0-500 nm. Speaking of the three-dimensional refractive index, the case of nx> ny = nz, nx> ny> nz, nx> nz> ny, nx = ny> nz (uniaxial, biaxial, Z-shaped, negative C plate) is preferable. When using a polarizing plate up and down of a liquid crystal cell, the upper and lower sides of a liquid crystal cell may have a phase difference, or any one of the upper and lower transparent protective films may have a phase difference.

For example, in the case of IPS (In-Plane Switching, FFS is included), when the transparent protective film on the one side of a polarizing plate has a phase difference, all can be used when it does not have. For example, when it does not have a phase difference, it is preferable when the upper and lower sides (cell side) of a liquid crystal cell do not have a phase difference. In the case of having a phase difference, when both the upper and lower sides of the liquid crystal cell have a phase difference, it is preferable that either one of the upper and lower sides has a phase difference (for example, when Z is at the upper side and there is no phase difference at the lower side, or on the upper side, A plate, positive C plate on the bottom). When it has a phase difference, the range of Re = -500-500 nm and Rth = -500-500 nm is preferable. In terms of three-dimensional refractive index, nx> ny = nz, nx> nz> ny, nz> nx = ny, nz> nx> ny (uniaxial, Z, positive C plate, positive A plate) are preferable.

Moreover, the film which has the said phase difference can be attached separately to the transparent protective film which does not have a phase difference, and can provide the said function.

In order to improve the adhesiveness with a polarizer, the said transparent protective film may perform surface modification process, before coating an adhesive agent. Specific treatments include corona treatment, plasma treatment, frame treatment, ozone treatment, primer treatment, glow treatment, saponification treatment, treatment with a coupling agent, and the like.

The surface which does not adhere | attach the polarizer of the said transparent protective film may be the thing which performed the process for the purpose of a hard-coat process, an antireflection process, sticking prevention, and a diffusion | diffusion or antiglare.

The hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate, and for example, adding a cured film having excellent hardness and sliding properties by suitable ultraviolet curable resins such as acrylic and silicone to the surface of the transparent protective film. It can form in a manner etc. The antireflection treatment is performed for the purpose of preventing the reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the prior art. In addition, the sticking prevention treatment is performed for the purpose of preventing adhesion to an adjacent layer (for example, a diffuser plate on the backlight side).

In addition, antiglare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing plate and impairing the visibility of the polarizing plate transmitted light. For example, a roughening method using a sand blasting method or an embossing processing method. It can form by providing a fine concavo-convex structure to the surface of a transparent protective film by a suitable method, such as a compounding method of transparent fine particles. Examples of the fine particles to be included in the formation of the surface fine uneven structure include an electrically conductive material composed of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, or the like having an average particle diameter of 0.5 to 20 µm, for example. Transparent microparticles | fine-particles, such as organic microparticles | fine-particles which consist of an inorganic type microparticle, a crosslinked or uncrosslinked polymer, etc. are used. When forming a surface fine uneven structure, the usage-amount of microparticles | fine-particles are about 2-70 weight part generally with respect to 100 weight part of transparent resin which forms a surface fine uneven structure, and 5-50 weight part is preferable. The antiglare layer may also serve as a diffusion layer (visual magnification function, etc.) for diffusing the polarizing plate transmitted light to enlarge the time and the like.

The antireflection layer, the sticking prevention layer, the diffusion layer, the antiglare layer and the like can be formed on the transparent protective film itself, and can be formed separately from the transparent protective film as an optical layer.

The adhesive layer used for the attachment of the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of water-based, solvent-based, hot-melt, radical-curable (electron-curable, UV-curable) types are used. Adhesives or radical curable adhesives are preferred.

Examples of the aqueous adhesive include polyvinyl alcohol, gelatin, vinyl latex, polyurethane, isocyanate, polyester, epoxy, and the like. The adhesive may contain various crosslinking agents. Moreover, the said adhesive agent can also mix | blend stabilizers, such as a catalyst, a coupling agent, various tackifiers, a ultraviolet absorber, antioxidant, a heat resistant stabilizer, and a hydrolysis stability stabilizer. Moreover, the sol or filler of metal compounds, such as alumina and a silica, can also be added to the said adhesive agent. Solid content of the adhesive is generally used at 0.1 to 20% by weight.

Moreover, as an optical film used for the adhesive optical film of this invention, in addition to the said polarizing plate, the above-mentioned phase difference plates (including wavelength plates, such as 1/2, 1/4, etc.) can be used independently. In addition, when used for formation of a liquid crystal display device, such as a reflecting plate, a semi-transmissive plate, a retardation plate (including wavelength plates, such as 1/2 or a quarter), an optical compensation film, a brightness enhancement film, etc., for example The thing which becomes an optical layer with is mentioned. These can be used independently as an optical film, can be laminated | stacked on the said polarizing plate at the time of practical use, and can use 1 layer or 2 or more layers.

In particular, a reflective polarizer or semi-transmissive polarizer in which a reflection plate or a semi-transmissive reflector is laminated on the polarizing plate, an elliptically polarizing plate or circular polarizer in which a retardation plate is further laminated on the polarizing plate, and a light in which a visual compensation film is further laminated on the polarizing plate The polarizing plate in which a brightness improving film is further laminated | stacked on a viewing angle polarizing plate or a polarizing plate is preferable.

The reflective polarizer is formed by forming a reflective layer on the polarizer, and is used to form a liquid crystal display device of a type that reflects and displays incident light from the visual recognition side (display side), and can incorporate a light source such as a backlight. It has advantages such as easy thinning of the liquid crystal display device. Formation of a reflective polarizing plate can be performed by a suitable method, such as the method of laying a reflective layer which consists of metal etc. on the single side | surface of a polarizing plate through a transparent protective layer etc. as needed.

As a specific example of a reflective polarizing plate, what provided the reflective layer by laying the foil and vapor deposition film which consist of reflective metals, such as aluminum, on the single side | surface of the transparent protective film which carried out the mat process as needed. Moreover, what contains microparticles | fine-particles in the said transparent protective film to make surface fine concavo-convex structure, and has a reflective layer of a fine concavo-convex structure on it, etc. are mentioned. The above-described reflective layer of the fine concavo-convex structure has the advantage of being able to diffuse incident light by diffuse reflection to prevent directivity and glare glare and to suppress unevenness of light and dark. Moreover, the fine particle-containing transparent protective film also has the advantage that it can spread | diffuse when incident light and its reflected light transmit it, and can suppress a brightness-and-light nonuniformity more. The formation of the reflective layer having a fine uneven structure reflecting the surface fine uneven structure of the transparent protective film, for example, transparent protection of the metal by an appropriate method such as a vapor deposition method such as a vacuum deposition method, an ion plating method, a sputtering method, or a plating method. It can carry out by the method of directly laying on the surface of a layer.

The reflecting plate can be used as a reflecting sheet or the like formed by forming a reflecting layer on a suitable film according to the transparent film instead of the method of directly applying to the transparent protective film of the polarizing plate. In addition, since the reflective layer is usually made of a metal, the use mode in which the reflective surface is covered with a transparent protective film, a polarizing plate, or the like prevents the reduction of the reflectance due to oxidation, and furthermore, the long-term sustained surface of the initial reflectance or the protective layer. It is preferable in terms of avoiding the separate laying of.

In addition, a semi-transmissive polarizing plate can be obtained by making it the semi-transmissive reflective layer, such as the half-mirror which reflects light by the reflective layer and transmits in the above. The semi-transmissive polarizing plate is usually formed on the back side of the liquid crystal cell, and when using a liquid crystal display device or the like in a relatively bright atmosphere, reflects incident light from the viewing side (display side) to display an image, and in a relatively dark atmosphere, A liquid crystal display device of a type for displaying an image and the like can be formed by using a built-in light source such as a backlight built in the back side of the transflective polarizing plate. That is, the transflective polarizing plate can save energy of light source use such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device of the type that can be used using a built-in light source even in a relatively dark atmosphere.

An elliptical polarizing plate or circular polarized light in which a retardation plate is further laminated on the polarizing plate will be described. A retardation plate or the like is used to change linearly polarized light into elliptical polarization or circularly polarized light, to change elliptical polarization or circularly polarized light into linearly polarized light, or to change the polarization direction of linearly polarized light. In particular, a so-called quarter wave plate (also referred to as λ / 4 plate) is used as the phase difference plate which changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. The half wave plate (also called a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

The elliptical polarizing plate is effectively used for compensating (preventing) the coloration (blue or yellow color) generated by the birefringence of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device, for displaying in black and white without coloration. In addition, it is preferable to control the three-dimensional refractive index because the coloring degree generated when the screen of the liquid crystal display device is viewed in the oblique direction can be prevented (prevented). The circularly polarizing plate is effectively used, for example, when arranging the color tone of an image of a reflection type liquid crystal display device in which an image becomes color display, and also has a function of antireflection. As a specific example of the retardation plate described above, a film made of a suitable polymer such as polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene or other polyolefins, polyarylates, and polyamides is formed by stretching treatment. The birefringent film, the orientation film of a liquid crystal polymer, the thing which supported the orientation layer of a liquid crystal polymer with a film, etc. are mentioned. The retardation plate may have a suitable retardation according to the purpose of use, for example, for the purpose of compensating coloring or vision due to birefringence of various wavelength plates and liquid crystal layers, or by laminating two or more kinds of retardation plates. The thing which controlled optical characteristics, such as a phase difference, may be sufficient.

Moreover, said elliptical polarizing plate and reflective elliptic polarizing plate laminate | stack a polarizing plate or a reflection type polarizing plate, and a phase difference plate by a suitable combination. Such elliptical polarizing plates and the like can also be formed by sequentially stacking them separately in the manufacturing process of the liquid crystal display device so as to be a combination of the (reflective) polarizing plate and the retardation plate. It is excellent in stability of quality, lamination workability, etc., and there exists an advantage which can improve manufacturing efficiency, such as a liquid crystal display device.

The visual compensation film is a film for enlarging a viewing angle so that an image may be seen comparatively clearly, even when the screen of a liquid crystal display device is seen from a slightly inclined direction rather than perpendicular to a screen. As such a visually compensating retardation plate, it consists of what supported the alignment layers, such as a liquid crystal polymer, on orientation films, such as a retardation film and a liquid crystal polymer, or a transparent base material, etc., for example. A conventional retardation plate is a polymer film having birefringence stretched biaxially in the plane direction while a polymer film having birefringence stretched uniaxially in the plane direction is used. For example, a biaxially stretched film such as a birefringent polymer or a diagonally oriented film, which has a refractive index in the thickness direction which is stretched in one plane in the plane direction and also in the thickness direction, is used. As the diagonally oriented film, for example, a heat-shrinkable film is adhered to a polymer film, and the polymer film is stretched or / and shrunk under the action of the shrinkage force by heating, or the diagonally oriented liquid crystal polymer is mentioned. have. As the raw material polymer of the retardation plate, the same polymer as that described in the retardation plate is used, and is suitable for the purpose of preventing the coloring due to the change of the viewing angle based on the phase difference by the liquid crystal cell, or the expansion of the viewing angle of the good visibility. Can be used.

Moreover, the optical compensation retardation plate which supported the optically anisotropic layer which consists of the alignment layer of a liquid crystal polymer, especially the diagonal alignment layer of a discotic liquid crystal polymer, etc. can be used preferably at the point of achieving the wide viewing angle of favorable visibility. .

The polarizing plate which affixed the polarizing plate and a brightness improving film is normally formed in the back side of a liquid crystal cell, and is used. The brightness enhancement film reflects linearly polarized light on a predetermined polarization axis or circularly polarized light in a predetermined direction when natural light is incident due to a backlight such as a liquid crystal display, reflection from the back side, or the like, and exhibits a characteristic that other light is transmitted. The polarizing plate laminated | stacked with the polarizing plate injects light from light sources, such as a backlight, and acquires the transmitted light of a predetermined polarization state, and light other than the said predetermined polarization state is reflected without being transmitted. The light reflected from the surface of the brightness enhancing film is again inverted through a reflecting layer or the like formed on the rear side thereof, and reincident to the brightness enhancing film, and a part or all of the light is transmitted as light in a predetermined polarization state to increase the amount of light passing through the brightness enhancing film. In addition, the luminance can be improved by supplying polarized light that is hardly absorbed by the polarizer and increasing the amount of light that can be used for liquid crystal display image display. That is, when light is made to pass through a polarizer from the back side of a liquid crystal cell with a backlight etc. without using a brightness enhancement film, the light which has a polarization direction which does not correspond to the polarization axis of a polarizer is absorbed by a polarizer and a polarizer It does not penetrate. That is, although it changes also with the characteristic of the polarizer used, about 50% of light is absorbed by a polarizer, and the quantity of light which can be used for a liquid crystal image display etc. is reduced by that, and an image becomes dark. The brightness enhancement film repeatedly reflects light having a polarization direction absorbed by the polarizer in the brightness enhancement film without being incident on the polarizer, inverts it through a reflective layer formed on the back side thereof, and reenters the brightness enhancement film, Since only the polarization direction in which the polarization direction of the light reflected and inverted between the two becomes the polarization direction through which the polarizer can pass, the brightness enhancement film is transmitted and supplied to the polarizer, so that light such as a backlight can be efficiently applied to the image display of the liquid crystal display device. It can be used to brighten the screen.

A diffusion plate can be formed between the brightness enhancing film and the reflective layer. The light in the polarization state reflected by the brightness enhancement film is directed toward the reflection layer or the like, but the diffuser plate provided uniformly diffuses the light passing therethrough and at the same time eliminates the polarization state and becomes a non-polarization state. In other words, the diffusion plate returns the polarized light to the original natural light state. The light in this non-polarized state, that is, in the natural light state, is directed toward the reflective layer or the like, is reflected through the reflective layer or the like, and passes through the diffuser plate again and is reincident to the brightness enhancing film. Thus, by forming a diffuser plate that returns the polarization to the original natural light state between the brightness enhancement film and the reflective layer, while maintaining the brightness of the display screen, while reducing the brightness unevenness of the display screen, to provide a uniform and bright screen can do. By forming such a diffuser plate, it is conceivable that the first incident light can be appropriately increased in the number of times of repetition of reflection, and can provide a uniform bright display screen with the diffuser function of the diffuser plate.

As said brightness improving film, the cholesteric which shows the characteristic which permeate | transmits linearly polarized light of a predetermined polarization axis | shaft and reflects other light, such as the multilayered thin film of a dielectric material and the multilayer laminated body of the thin film film from which refractive index anisotropy differs, for example, is a cholesteric Suitable ones, such as those in which the circularly polarized light of either one of left rotation or right rotation is reflected and other light is transmitted, such as supporting the alignment film of the liquid crystal polymer or the alignment liquid crystal layer on the film substrate, can be used.

Therefore, in the brightness improvement film of the type which permeate | transmits linearly polarized light of the said predetermined polarization axis, it can transmit efficiently, restraining the absorption loss by a polarizing plate by making the transmitted light into a polarizing plate as it enters. On the other hand, in the luminance improvement film of the type which transmits circularly polarized light like a cholesteric liquid crystal layer, although it may be made to enter into a polarizer as it is, in order to suppress absorption loss, the circularly polarized light is polarized linearly through a phase difference plate, and a polarizing plate It is preferable to make it enter. In addition, by using a quarter wave plate as the retardation plate, circularly polarized light can be converted into linearly polarized light.

The phase difference plate which functions as a quarter wave plate in a wide wavelength range, such as visible region, is a phase difference layer which shows a phase difference characteristic different from the phase difference layer which functions as a quarter wave plate with respect to pale light of wavelength 550 nm, for example, For example, it can obtain by the method of superimposing the retardation layer which functions as a 1/2 wave plate. Therefore, the phase difference plate arrange | positioned between a polarizing plate and a brightness improving film may consist of one layer or two or more phase difference layers.

Moreover, also about a cholesteric liquid crystal layer, when it is set as the arrangement structure which overlapped two or three layers by the combination of a thing with a different reflection wavelength, what reflects circularly polarized light in a wide wavelength range, such as a visible light region, can be obtained and Based on this, transmission circularly polarized light in a wide wavelength range can be obtained.

Moreover, the polarizing plate may consist of what laminated | stacked the polarizing plate and two or three or more optical layers like the said polarization split type polarizing plate. Therefore, the reflective elliptically polarizing plate, the semi-transmissive elliptically polarizing plate, etc. which combined said reflective polarizing plate, semi-transmissive polarizing plate, and retardation plate may be sufficient.

Although the optical film which laminated | stacked the said optical layer on the polarizing plate can also be formed also by the method of laminating | stacking separately one by one in the manufacturing process of a liquid crystal display device, etc., what laminated | stacked previously and made it into the optical film is that quality stability, assembly work, etc. It is excellent and there exists an advantage which can improve manufacturing processes, such as a liquid crystal display device. Suitable lamination means, such as an adhesion layer, can be used for lamination. At the time of adhering the polarizing plate or the other optical film, the optical axis can be set to an appropriate placement angle in accordance with a desired phase difference characteristic or the like.

The adhesive optical film of this invention can be used suitably for formation of various apparatuses, such as a liquid crystal display device. Formation of a liquid crystal display device can be performed according to the prior art. That is, the liquid crystal display device is generally formed by appropriately assembling a component such as a liquid crystal cell, a polarizing plate or an optical film, and an illumination system, if necessary, and mounting a driving circuit, but in the present invention, the polarizing plate according to the present invention. Or there is no limitation in particular except using an optical film, and it can follow conventionally. Also about a liquid crystal cell, what is arbitrary types, such as a TN type, STN type, (pi) type, VA type, IPS type, can be used, for example.

An appropriate liquid crystal display device, such as a liquid crystal display device in which a polarizing plate or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or reflecting plate used in an illumination system, can be formed. In that case, the polarizing plate or optical film by this invention can be provided in the one side or both sides of a liquid crystal cell. When forming a polarizing plate or an optical film in both sides, they may be the same and may differ. In the formation of the liquid crystal display device, for example, a diffuser plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, a backlight or the like, and suitable components in one or two layers at appropriate positions. You can place more than that.

Next, an organic electro luminescence apparatus (organic EL display apparatus) is demonstrated. In general, an organic EL display device forms a light emitting body (organic electro luminescence light emitting body) by sequentially stacking a transparent electrode, an organic light emitting layer, and a metal electrode on a transparent substrate. Here, an organic light emitting layer is a laminated body of various organic thin films, For example, the laminated body of the hole injection layer which consists of triphenylamine derivatives, etc., and the light emitting layer which consists of fluorescent organic solids, such as anthracene, or such a light emitting layer, and a pedestal There are known configurations having various combinations, such as a laminate of electron injection layers made of a rylene derivative and the like, or a laminate of these hole injection layers, a light emitting layer, and an electron injection layer.

In the organic EL display device, by applying a voltage to the transparent electrode and the metal electrode, holes and electrons are injected into the organic light emitting layer, and energy generated by recombination of these holes and electrons excites the fluorescent material, and the excited fluorescent material is It emits light on the principle of emitting light when returning to the ground state. The mechanism of intermediate recombination is the same as that of a general diode, and as can be expected from this point, the current and the emission intensity exhibit strong nonlinearity accompanied by rectification with respect to the applied voltage.

In the organic EL display device, in order to take out light emission from the organic light emitting layer, at least one electrode must be transparent, and a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is usually used as an anode. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and metal electrodes such as Mg-Ag and Al-Li are usually used.

In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film with a thickness of about 10 nm. For this reason, light is transmitted almost completely similarly to an organic light emitting layer like a transparent electrode. As a result, light incident on the surface of the transparent substrate during non-emission, and transmitted through the transparent electrode and the organic light emitting layer and reflected by the metal electrode again comes out to the surface side of the transparent substrate, therefore, when viewed from the outside, the organic EL display device The display surface of 같이 looks like a mirror surface.

An organic EL display device comprising an organic electroluminescent light-emitting body comprising a transparent electrode on the front side of an organic light emitting layer that emits light by application of a voltage and a metal electrode on the back side of the organic light emitting layer. While forming a polarizing plate on the surface side of an electrode, a phase difference plate can be formed between these transparent electrodes and a polarizing plate.

Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected from the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization action. In particular, when the phase difference plate is constituted by a quarter wave plate and the angle between the polarization direction of the polarizing plate and the phase difference plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded.

That is, only the linearly polarized light component is transmitted to the external light incident on the organic EL display device by the polarizing plate. This linearly polarized light is generally elliptically polarized by the retardation plate, but in particular, when the retardation plate is a quarter wave plate and the angle between the polarization direction of the polarizing plate and the retardation plate is? / 4, it is circularly polarized light.

The circularly polarized light is transmitted through the transparent substrate, the transparent electrode, and the organic thin film to be reflected by the metal electrode, and is then transmitted through the organic thin film, the transparent electrode and the transparent substrate, and is again linearly polarized by the retardation plate. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot pass through a polarizing plate. As a result, the mirror surface of a metal electrode can be shielded completely.

Example

Although an Example demonstrates this invention concretely below, this invention is not limited by these Examples. In addition, all the parts and% in each case are a basis of weight.

Preparation Example 1

<Preparation of acrylic adhesive>

In a four-necked flask equipped with a nitrogen inlet tube and a cooling tube, 96.5 parts of butyl acrylate, 3 parts of acrylic acid, 0.5 parts of 2-hydroxyethyl acrylate, 0.15 parts of 2,2'-azobisisobutyronitrile and ethyl acetate After adding 100 weight part and fully nitrogen-substituting, it was made to react at 60 degreeC for 8 hours, stirring under nitrogen stream, and the acrylic polymer solution of the weight average molecular weight 1.65 million was obtained. 0.5 part of isocyanate type crosslinking agents (Nippon Polyurethane Co., Ltd. make, colonate L) was mix | blended with respect to 100 parts of solid content of the said acrylic polymer solution, and the adhesive coating liquid (solid content 12%) was prepared.

Preparation Example 2

<Preparation of acrylic adhesive>

Into a four-necked flask equipped with a nitrogen inlet tube and a cooling tube, 99.5 parts of butyl acrylate, 0.5 part of 4-hydroxybutyl acrylate, 0.15 part of 2,2'-azobisisobutyronitrile and 100 parts by weight of ethyl acetate were added. The mixture was sufficiently nitrogen-substituted and reacted at 60 ° C. for 8 hours while stirring under a nitrogen stream to obtain an acrylic polymer solution having a weight average molecular weight of 1,650,000. 0.2 part of isocyanate type crosslinking agents (Nippon Polyurethane Co., Ltd. product, Colonate L) was mix | blended with respect to 100 parts of solid content of the said acrylic polymer solution, and the adhesive coating liquid (solid content 11.5%) was prepared.

Preparation Example 3

<Preparation of acrylic adhesive>

In a four-necked flask equipped with a nitrogen inlet tube and a cooling tube, 90 parts of butyl acrylate, 4 parts of acrylic acid, 5 parts of acryloyl morpholine, 1 part of 4-hydroxyethyl acrylate, 2,2'-azobisiso 0.15 part of butyronitrile and 100 weight part of ethyl acetate were thrown in, and fully nitrogen-substituted, it was made to react at 60 degreeC for 8 hours, stirring under nitrogen stream, and the acrylic polymer solution of the weight average molecular weight 1.65 million was obtained. 0.3 part of isocyanate type crosslinking agents (Nippon Polyurethane Co., Ltd. product, Colonate L) was mix | blended with respect to 100 parts of solid content of the said acrylic polymer solution, and the adhesive coating liquid (solid content 11.5%) was prepared.

<Polarizing plate>

The 80-micrometer-thick polyvinyl alcohol film was extended | stretched 5 times in aqueous solution of iodine, and it dried and obtained the polarizer. The transparent protective film (triacetyl cellulose film, thickness 80micrometer) was affixed on both sides of the said polarizer with the polyvinyl alcohol-type adhesive agent, and the polarizing plate was obtained.

Example 1

Adhesive coating liquid obtained by the manufacture example 1 on the release process surface (surface roughness 21 nm) of the polyester film (release sheet, Mitsubishi Chemical Polyester Co., Ltd. brand name, diamond foil MRF # 38, thickness 38micrometer) which performed the mold release process. After coating with a die coater so that a dry thickness might be set to 25 micrometers, the 1st drying process was implemented by sending the wind of 14 m / sec wind speed for 1 minute in 70 degreeC oven. Subsequently, a 2nd drying process was performed by sending the wind of temperature 155 degreeC and wind speed 15m / sec for 2 minutes, the adhesive layer was formed, and the adhesive sheet for optical films was obtained.

Examples 2-7, Comparative Examples 1-3

In Example 1, the adhesive sheet for optical films was obtained like Example 1 except having changed the kind of adhesive coating liquid, the conditions of a 1st drying process, and the conditions of a 2nd drying process as shown in Table 1.

The following evaluation was performed about the adhesive sheet for optical films obtained above. The results are shown in Table 1.

<Surface Roughness Ra: Surface Side>

Another release sheet (polyester film which performed the mold release process, the Mitsubishi Chemical Polyester company make, brand name dia foil MRF # 38, thickness 38micrometer) was stuck to the adhesive layer of the obtained adhesive sheet for optical films. Then, the release sheet which affixed originally was peeled off, and what was made to adhere to glass (Matsunami Glass Co., Ltd. make, MICROSLIDE GLASS) was made into the sample. About this sample, the surface roughness was measured using the WYKO NT3300 (non-contact three-dimensional roughness measuring apparatus and the Nippon-Biko company make) so that the release sheet which affixed later may become upper. The measurement was observed in the range of 20 mm x 20 mm, and three points and surface roughness were computed at 5 mm space | intervals in the direction perpendicular | vertical to the coating direction of an adhesive layer. In Table 1, the measured value (in parenthesis) of three points is shown with the average value of surface roughness. Moreover, surface roughness (Ra) is a value measured based on JISB0601.

<Surface Roughness Ra: Release Sheet Side>

Ra of the adhesive layer on the release sheet side simulates Ra of the mold release process surface of a release sheet. Therefore, Ra of the pressure-sensitive adhesive layer on the release sheet side measured the surface roughness of the release treated surface of the release sheet using a fine shape measuring instrument (three-dimensional surface shape measuring instrument) ET4000 (manufactured by Kosaka Research Institute). The measurement was observed in the range of 20 mm x 20 mm, and measured in the direction perpendicular | vertical to the coating direction of an adhesive layer. Moreover, surface roughness (Ra) is a value measured based on JISB0601.

<Visibility>

The adhesive layer of the obtained adhesive sheet for optical films was transferred to the polarizing plate, and the adhesive type polarizing plate was produced. After peeling a release sheet from the said adhesive polarizing plate, it attached to the portable panel of Sharp Co., Ltd., and visually observed visibility in 2 directions of the front and inclination 45 degrees by the following reference | standard.

◎: No problem in visibility.

(Circle): Some nonuniformity is confirmed, but a level without a problem.

X: There is a problem in visibility.

Claims (4)

As an adhesive sheet for optical films which has an adhesive layer on a release sheet, The surface roughness (Ra) of the surface of the said adhesive layer on the said release sheet is 2-150 nm, The adhesive sheet for optical films characterized by the above-mentioned. As a manufacturing method of the adhesive sheet for optical films of Claim 1, Process of coating adhesive coating liquid on a release sheet, An adhesive layer is formed by performing the said 1st drying process of the temperature of 30-80 degreeC, the wind speed of 0.5-15 m / sec, and the 2nd drying process of the temperature of 90-160 degreeC, and the wind speed of 0.1-25 m / sec to the said adhesive coating liquid. It has a process to make, The manufacturing method of the adhesive sheet for optical films. As an adhesive optical film which an optical film adhered to the said adhesive layer surface of the adhesive sheet for optical films which has an adhesive layer on a release sheet, The said adhesive sheet for optical films is the adhesive sheet for optical films of Claim 1, and the optical film was stuck to the adhesive layer surface whose surface roughness (Ra) is 2-150 nm, The adhesive optical film characterized by the above-mentioned. The image display apparatus which used at least one adhesive optical film from which the release sheet was peeled off from the adhesive optical film of Claim 3.

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