WO2006043449A1 - Antistatic adhesive optical film and image display - Google Patents

Abstract

Disclosed is an antistatic adhesive optical film with high light transmittance which is able to maintain excellent antistatic properties even after storage in high temperature environments. Such an antistatic adhesive optical film is characterized in that an antistatic layer is arranged on at least one side of an optical film, an adhesive layer is arranged on the antistatic layer, and the antistatic layer contains a carbon nanomaterial.

Description

 Specification

 Antistatic adhesive optical film and image display device

 Technical field

 The present invention relates to an antistatic pressure-sensitive adhesive optical film in which an antistatic layer is laminated on at least one surface of an optical film, and an adhesive layer is further laminated on the antistatic layer. The present invention also relates to an image display device such as a liquid crystal display device, an organic EL display device, and a PDP using the antistatic adhesive optical film. Examples of the optical film include a polarizing plate, a retardation plate, an optical compensation film, a brightness enhancement film, and a laminate of these.

 Background art

 In a liquid crystal display or the like, it is indispensable to dispose polarizing elements on both sides of the liquid crystal cell, and generally polarizing plates are attached. In addition to polarizing plates, various optical elements are being used for liquid crystal panels in order to improve the display quality of displays. For example, a retardation plate for preventing coloring, a viewing angle widening film for improving the viewing angle of a liquid crystal display, and a brightness enhancement film for increasing the contrast of the display are used. These films are collectively called optical films.

[0003] These optical films are usually used in the transportation and manufacturing process until they are delivered to consumers! The surface of the optical film is protected from scratches and dirt. Rum is pasted together. The surface protective film may be peeled off after being attached to an LCD or the like, or the same or another surface protective film may be attached again after being peeled off once. And when peeling off this surface protection film, static electricity generate | occur | produced and there existed a problem that circuits, such as an LCD panel, were destroyed by this static electricity. In addition, there is a problem that the array elements inside the LCD panel are affected, which further affects the alignment of the liquid crystal and induces defects. Further, the surface protection film is not only peeled off, but the same problem occurs due to friction between optical films depending on the manufacturing process and the usage method of consumers. In order to solve the above problem, an antistatic property is imparted to an optical film such as a polarizing plate. And have been proposed. For example, an optical film with an antistatic layer provided with an antistatic layer on the surface of the optical film, and a film provided with a transparent conductive layer on one side or both sides of the optical film are disclosed (Patent Document 1).

 [0004] On the other hand, an adhesive is usually used when adhering an optical film to a liquid crystal cell. In addition, since the adhesion between the optical film and the liquid crystal cell or the optical film usually reduces the loss of light, the respective materials are adhered using an adhesive. In such a case, the pressure-sensitive adhesive has a merit that a drying process is not required to fix the optical film, and thus the pressure-sensitive adhesive is a pressure-sensitive adhesive optical film previously provided as a pressure-sensitive adhesive layer on one side of the optical film. Film is commonly used.

 [0005] In use, the adhesive optical film is cut into a display size. When handling in the intensive use process, if the end (cutting part) of the adhesive optical film comes into contact with a person or device, the adhesive may be lost at that part. When such an adhesive type optical film lacking an adhesive is attached to a liquid crystal cell, the lacked part does not adhere, so that there is a problem that light is reflected at that part, resulting in a display defect. In particular, the display frame has been narrowed recently, and the display quality is significantly deteriorated due to the defects occurring at the edge. In addition, when the adhesive optical film is attached to the liquid crystal panel and then peeled off from the panel cover for reasons such as foreign matter mixing, there will be no trouble that the adhesive remains on the panel side (so-called adhesive residue phenomenon). That is, it is desired that reworkability is good.

 [0006] It has been proposed to impart antistatic properties to the adhesive optical film. For example, an antistatic adhesive optical film in which an antistatic layer containing carbon black, an ionic polymer, a surfactant, or a metal oxide is provided between the optical film and the adhesive layer has been proposed. (Patent Document 2). However, when carbon black is used as an antistatic agent, there is a problem that the light transmittance of the optical film is lowered. In addition, when an ionic polymer, a surfactant, or a metal oxide is used as an antistatic agent, there is a problem that the antistatic performance is lowered after the antistatic optical film is stored in a high temperature environment. .

 [0007] Patent Document 1: Japanese Patent Laid-Open No. 7-26223

Patent Document 2: JP-A-11-91038 Disclosure of the invention

 Problems to be solved by the invention

 [0008] The present invention is an antistatic pressure-sensitive adhesive optical film in which an antistatic layer is laminated on at least one surface of an optical film, and an adhesive layer is further laminated on the antistatic layer, and has an optical transmittance. The object is to provide a product that can maintain excellent antistatic performance even after being stored in a high temperature environment. It is another object of the present invention to provide an image display device using the antistatic adhesive optical film.

 Means for solving the problem

[0009] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the following antistatic adhesive optical film, and have completed the present invention.

 That is, in the present invention, an antistatic layer is laminated on at least one surface of an optical film, and an adhesive layer is further laminated on the antistatic layer, and the antistatic layer contains a carbon nanomaterial. The present invention relates to an antistatic pressure-sensitive adhesive optical film.

[0011] By using carbon nanomaterials, particularly carbon nanotubes, as an antistatic agent, an antistatic layer is formed that has high light transmittance and can maintain excellent antistatic performance even after storage in a high temperature environment. can do. The reason why such an effect appears is not clear, but carbon nanomaterials are generally very small carbon substances with a size of nm, so it is considered that light reflection and scattering can be effectively prevented. . In addition, since it has a stable SP ² structure even in a high temperature environment, it is thought that excellent antistatic performance can be maintained even after storage in a high temperature environment.

[0012] The antistatic layer preferably further contains a binder component. The binder component is preferably at least one selected from the group consisting of polyurethane-based resin, polyester-based resin and acrylic-based resin. By using such a resin, the adhesive strength between the antistatic layer and the optical film or the pressure-sensitive adhesive layer is improved.

[0013] The antistatic layer preferably further contains a dispersant.

[0014] The pressure-sensitive adhesive layer is preferably formed of an acrylic pressure-sensitive adhesive.

[0015] Further, the present invention is a method for producing the antistatic pressure-sensitive adhesive optical film, It includes a step of applying a dispersion containing a carbon nanomaterial on at least one surface of an optical film and drying to form an antistatic layer, and a step of forming an adhesive layer on the antistatic layer. Relates to a method for producing an antistatic adhesive optical film,

[0016] The present invention relates to an image display device using at least one antistatic adhesive optical film. The antistatic pressure-sensitive adhesive optical film of the present invention is used in combination of one or more sheets depending on various usages of an image display device such as a liquid crystal display device.

 Brief Description of Drawings

FIG. 1 is an example of a cross-sectional view of an antistatic pressure-sensitive adhesive optical film of the present invention.

 Explanation of symbols

[0018] 1 Optical film

 2 Antistatic layer

 3 Adhesive layer

 BEST MODE FOR CARRYING OUT THE INVENTION

In the antistatic pressure-sensitive adhesive optical film of the present invention, as shown in FIG. 1, an antistatic layer 2 and an adhesive layer 3 are laminated in this order on one side of the optical film 1. FIG. 1 shows the case where the adhesive layer 3 is provided on one side of the optical film 1, but the adhesive layer 3 may be provided on both sides of the optical film. Further, the pressure-sensitive adhesive layer 3 on the other side may have the antistatic layer 2.

 [0020] The antistatic layer 2 of the antistatic pressure-sensitive adhesive optical film of the present invention is formed of a composition containing a forceful nanomaterial as an antistatic agent.

[0021] Examples of the carbon nanomaterial include carbon nanotubes, carbon nanohorns, strong bon nanowalls, and fullerenes. Of these, carbon nanotubes are preferably used. Carbon nanotubes generally have a hollow fiber shape, and are carbon materials having a diameter of about 0.5 nm to 5 μm and a length of about 10 nm to 1000 μm. In the present invention, it is preferable to use a carbon nanotube having a diameter of 0.5! 1! 11 to 1111, and a length of 1011111 to 100111. [0022] As the antistatic agent, a conductive polymer may be used together with the carbon nanomaterial. As the conductive polymer, a polymer having good optical characteristics, appearance, antistatic effect and antistatic effect when heated and humidified is used. Examples of such a conductive polymer include polymers such as polyarine, polythiophene, polypyrrole, and polyquinoxaline. Among these, polyaniline, polythiophene, and the like that are likely to become a water-soluble conductive polymer or a water-dispersible conductive polymer are preferably used. Polythiophene is particularly preferable.

 [0023] An optical film such as a polarizing plate is soluble in a non-aqueous organic solvent and tends to be deteriorated or deteriorated to deteriorate optical characteristics. As described above, since the optical film is inferior in organic solvent resistance, the coating liquid for forming the antistatic layer is preferably an aqueous dispersion in which carbon nanomaterial is dispersed in water. The aqueous dispersion may contain a hydrophilic solvent together with water. Examples of the hydrophilic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert -Alcohols such as Amylano Noreconole, 1-Etenore 1-Prono Norre, 2-Methinore 1-Butanol Monore, n-Hexanol, and Cyclohexanol.

[0024] As the material for forming the antistatic layer, it is preferable to use a binder component together with the carbon nanomaterial for the purpose of improving the film forming property of the antistatic agent and the adhesion to the optical film. In particular, it is preferable to use a water-soluble or water-dispersible binder component. Examples of the noinder component include polyurethane-based resins, polyester-based resins, talyl-based resins, polyether-based resins, cellulose-based resins, polybulal alcohol-based resins, epoxy resins, polybululpyrrolidone, polystyrene. Examples thereof include polyethylene resin, polyethylene glycol, and pentaerythritol. In particular, polyurethane-based resin, polyester-based resin, and acrylic-based resin are preferred. These binder components can be used alone or in combination of two or more as appropriate. For example, when the carbon nanomaterial is a carbon nanotube, it is preferable that the carbon nanotube is less than 100 parts by weight with respect to 100 parts by weight of the binder component. Parts by weight. [0025] Further, as a material for forming the antistatic layer, it is preferable to use a dispersant together with the carbon nanomaterial for the purpose of improving the dispersibility of the carbon nanomaterial. Examples of the dispersant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and a resin used as a binder such as polyvinylpyrrolidone. These dispersants can be used alone or in combination of two or more as appropriate. The amount of the dispersant used depends on the type of the carbon nanomaterial. 100 to 100 parts by weight of the carbon nanomaterial 0.1 to: LOOO parts by weight is preferable, and more preferably 1 to: LOO parts by weight. is there.

[0026] The surface resistance value of the antistatic layer is preferably 1 × 10 ¹² Ω well or less, more preferably 1 × 10 ¹¹ Ω well or less. If the surface resistance exceeds 1 X 10 ¹² Ω, the static electricity is generated due to peeling of the surface protection film with insufficient antistatic function or the friction of the optical film. It may cause liquid crystal alignment failure.

 [0027] The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 3 of the antistatic pressure-sensitive adhesive optical film of the present invention is not particularly limited, and examples thereof include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyetherols, fluorine-based polymers. Those having a base polymer of a polymer such as rubber or the like can be appropriately selected and used. In particular, those excellent in optical transparency, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties and excellent in weather resistance and heat resistance are preferably used. An acrylic pressure-sensitive adhesive is preferably used to exhibit such characteristics.

[0028] The acrylic pressure-sensitive adhesive has an acrylic polymer having a main skeleton of an alkyl (meth) acrylate monomer unit as a base polymer. In addition, (meta) attalate refers to attalate and cocoon or metatarate, and (meta) in the present invention has the same meaning. The average number of carbon atoms of the alkyl group of the alkyl (meth) acrylate that constitutes the main skeleton of the acrylic polymer is about 1 to 12, and specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate. Examples thereof include rate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethyl hexyl (meth) acrylate, etc., and these can be used alone or in combination. Of these, alkyl (meth) acrylates having 1 to 9 carbon atoms in the alkyl group are preferred. [0029] In the acrylic polymer, one or more kinds of monomers are introduced by copolymerization for the purpose of improving adhesiveness and heat resistance. Specific examples of such copolymerization monomers include (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid 4-hydroxybutyl, and (meth) acrylic acid. 6-hydroxyhexyl, (meth) acrylic acid 8 hydroxyoctyl, (meth) acrylic acid 10 hydroxydecyl, (meth) acrylic acid 12-hydroxylauryl and (4-hydroxymethylcyclohexyl) monomethyl acrylate Hydroxyl group-containing monomers; (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and other carboxyl group-containing monomers; maleic anhydride Monomers containing acid anhydride groups such as acid and itaconic anhydride; Rataton adducts: styrene sulfonic acid, gallic sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) attaylloy oxynaphthalene sulfonic acid And sulfonic acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

 [0030] In addition, (N-substituted) amides such as (meth) acrylamide, N, N dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, etc. (Meth) acrylic acid aminoethyl, (meth) acrylic acid and N dimethylaminoethyl, (meth) acrylic acid t-butylaminoethyl and other (meth) acrylic acid alkylaminoalkyl monomers; (meth) acrylic acid methoxy ester (Meth) acrylic acid alkoxyalkyl monomers such as (meth) acrylic acid ethoxyethyl; N— (meth) acryloyloxymethylene succinimide N— (meth) acryloyl 1-oxyhexamethylene succinimide, N— ( Meta) Atari Roy Roux 8—Oxiota Methylol succinimides, also including succinimide-based monomers such as N- Atari acryloyl morpholine and the like as a monomer Examples of the reforming purposes.

[0031] Further, butyl acetate, butyl propionate, N butyl pyrrolidone, methyl pyrrol pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, bur pyrrole, bul imidazole, buroxazole, bul morpholine, N Vinore strength norevonamide, styrene, α-methylol styrene, Ν Vinole strength pro Bullet monomers such as cutams; Cyanacrylate monomers such as acrylonitrile and methacrylic mouth-tolyl; Epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; Polyethylene glycol (meth) acrylate, Polypropylene (meth) acrylate Glycol-based acrylic ester monomers such as glycol, (meth) acrylic acid methoxyethylene glycol, and (meth) acrylic acid methoxypolypropylene glycol; (meth) acrylic acid tetrahydrofuryl, fluorine (meth) acrylate, silicone (meth) acrylate Acrylic acid ester monomers such as 2-methoxyethyl acrylate can also be used.

 Among these, carboxyl group-containing monomers such as acrylic acid are preferably used from the viewpoints of adhesion to liquid crystal cells and adhesion durability for optical film applications.

 [0033] The proportion of the copolymerization monomer in the acrylic polymer is not particularly limited, but is preferably about 0.1 to 10% by weight.

 [0034] 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. The acrylic polymer can be produced by various known methods. For example, a radical polymerization method such as a Balta polymerization method, a solution polymerization method, or a suspension polymerization method can be appropriately selected. As the radical polymerization initiator, various known ones such as azo and peroxide can be used. The reaction temperature is usually about 50-80 ° C, and the reaction time is 1-8 hours. Among the above production methods, ethyl acetate, toluene and the like are generally used as the solvent for the acrylic polymer for which the solution polymerization method is preferred. The solution concentration is usually about 20 to 80% by weight.

 [0035] Examples of the base polymer of the rubber adhesive include natural rubber, isoprene rubber, styrene butadiene rubber, recycled rubber, polyisobutylene rubber, styrene-soprene styrene rubber, styrene butadiene styrene. System rubber and the like. Examples of the base polymer for the silicone-based pressure-sensitive adhesive include dimethylpolysiloxane and diphenylpolysiloxane. These base polymers can also be used in which functional groups such as carboxyl groups are introduced.

[0036] The pressure-sensitive adhesive is preferably a pressure-sensitive adhesive composition containing a crosslinking agent. Examples of the polyfunctional compound that can be added to the pressure-sensitive adhesive include organic crosslinking agents and polyfunctional metal chelates. Examples of organic crosslinking agents include epoxy crosslinking agents, isocyanate crosslinking agents, imine Examples thereof include a system cross-linking agent. As the organic crosslinking agent, an isocyanate crosslinking agent is preferred. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Multivalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, etc. Can be given. Examples of the atoms in the organic compound to be covalently bonded or coordinated include oxygen atoms, and examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

 [0037] The mixing ratio of the base polymer such as acrylic polymer and the crosslinking agent is not particularly limited! However, usually, the crosslinking agent (solid content) is preferably about 0.01 to 10 parts by weight and more preferably about 0.1 to 5 parts by weight with respect to 100 parts by weight of the base polymer (solid content).

 [0038] Sarakuko has a tackifier, a plasticizer, glass fiber, glass beads, metal powder, other inorganic powders, a filler, a pigment, a colorant, and the like as necessary. Fillers, antioxidants, ultraviolet absorbers, silane coupling agents, and the like, and various additives can be appropriately used within the range V and without departing from the object of the present invention. Moreover, it is good also as an adhesive layer etc. which contain microparticles | fine-particles and show light diffusibility.

 [0039] As the optical film 1 used for the antistatic pressure-sensitive adhesive optical film of the present invention, those used for forming an image display device such as a liquid crystal display device are used, and the type thereof is not particularly limited. For example, the optical film includes a polarizing plate. As the polarizing plate, one having a transparent protective film on one side or both sides of the polarizer is generally used.

 [0040] The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymer films such as polybulal alcohol film, partially formalized polybulal alcohol film, and ethylene / acetic acid copolymer partial ken film, and iodine and dichroic dyes. Examples include uniaxially stretched films by adsorbing dichroic substances, and polyvinyl-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. Among these, a polybulol alcohol film and a polarizer having dichroic substance power such as iodine are preferable. The thickness of these polarizers is not particularly limited. Generally, the thickness is about 5 to 80 μm.

A polarizer obtained by uniaxially stretching a polyvinyl alcohol film dyed with iodine is, for example, It can be prepared by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can also be immersed in an aqueous solution of potassium iodide or the like which may contain boric acid, zinc sulfate, zinc chloride and the like. Furthermore, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. By washing the polybulal alcohol-based film with water, it is possible to clean the surface of the polybulal alcohol-based film and the anti-blocking agent, and by swelling the polyvinyl alcohol-based film, unevenness such as uneven dyeing can be achieved. There is also an effect to prevent. The stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be stretched and dyed with strong iodine. The film can be stretched even in an aqueous solution of boric acid or potassium iodide or in a water bath.

 [0042] As a material for forming a transparent protective film provided on one or both sides of the polarizer, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like is preferable. . For example, polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate, cenorelose-based polymers such as dicetinoresenorelose and triacetinoloselenolose, acrylic polymers such as polymethylmethacrylate, polystyrene and Examples include styrene polymers such as styrene copolymers (AS resin) and polycarbonate polymers. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, salt bubul polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, Snorephone-based polymer, Polyetherenorenolephone-based polymer, Polyethylene-noreno-ketone-based polymer, Polyphenylene sulfide-based polymer, Vinyl alcohol-based polymer, Vinylidene chloride-based polymer, Vinyl butyral-based polymer, Arylate-based polymer, Polyoxymethylene-based Examples of the polymer that forms the transparent protective film include polymers, epoxy polymers, and blends of the above polymers. The transparent protective film can also be formed as a cured layer of thermosetting or ultraviolet curable resin such as acrylic, urethane, acrylurethane, epoxy, and silicone.

[0043] Further, a polymer film described in JP-A-2001-343529 (WO01Z37007), for example, (A) a thermoplastic resin having a substituted side chain and a Z or non-midamide group; (B) A resin composition containing a thermoplastic resin having substituted and Z or unsubstituted fullyl and -tolyl groups in the side chain. A specific example is a film of a resin composition containing an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a strong film such as a mixed extruded product of the resin composition can be used.

 [0044] The thickness of the protective film can be appropriately determined, but is generally about 1 to 500 m from the viewpoints of workability such as strength and handleability, and thin film properties. In particular, 5 to 200 m is preferable.

 [0045] The protective film should be as colored as possible! I like it! /. Therefore, Rth = (nx

 -nz) * d (where nx is the refractive index in the slow axis direction in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness). A protective film having a thickness of 90 nm to +75 nm is preferably used. By using a film having a thickness direction retardation value (Rth) of 90 nm to +75 nm, the coloring (optical coloring) of the polarizing plate caused by the protective film can be almost eliminated. The thickness direction retardation (Rth) is more preferably from 80 nm to +60 nm, and particularly preferably from 70 nm to +45 nm.

 [0046] As the protective film, a cellulose polymer such as triacetyl cellulose is preferred from the viewpoints of polarization characteristics and durability. A triacetyl cellulose film is particularly preferable. In the case where protective films are provided on both sides of the polarizer, protective films having the same polymer material strength may be used on the front and back sides, or different protective films having the same polymer material strength may be used. The polarizer and the protective film are usually in close contact with each other through an aqueous adhesive or the like. Examples of water-based adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based, water-based polyurethane, water-based polyester, and the like.

 [0047] The surface of the transparent protective film to which the polarizer is not adhered may be subjected to a hard coat layer, an antireflection treatment, an anti-sticking treatment, or a treatment for diffusion or anti-glare.

[0048] The hard coat treatment is performed for the purpose of preventing the surface of the polarizing plate from being scratched. For example, curing with excellent UV hardness curable resin such as acrylic and silicone is excellent in hardness and sliding properties. Form the film by applying a film to the surface of the transparent protective film. You can. The antireflection treatment is performed for the purpose of preventing 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 conventional art. In addition, the sticking prevention treatment is performed for the purpose of preventing adhesion with an adjacent layer of another member.

 [0049] The anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing plate and obstructing the visual recognition of the light transmitted through the polarizing plate. It can be formed by imparting a fine concavo-convex structure to the surface of the transparent protective film by an appropriate method such as a surface roughening method or a method of blending transparent fine particles. Examples of the fine particles to be included in the formation of the surface fine concavo-convex structure include silica, alumina, titanium dioxide, zirconium oxide, tin oxide, indium oxide, cadmium oxide, and acid oxide having an average particle diameter of 0.5 to 50 μm. Transparent fine particles such as inorganic fine particles that may have conductivity such as antimony and organic fine particles (including beads) that also have crosslinked or uncrosslinked polymer are used. In the case of forming a surface fine concavo-convex structure, the amount of fine particles used is generally about 2 to 50 parts by weight per 100 parts by weight of the transparent resin forming the surface fine concavo-convex structure, and 5 to 25 parts by weight preferable. The anti-glare layer may also serve as a diffusion layer (such as a visual enlargement function) for diffusing the light transmitted through the polarizing plate to enlarge vision.

 [0050] The antireflection layer, the anti-sticking layer, the diffusion layer, the antiglare layer, and the like can be provided on the transparent protective film itself, or separately from the transparent protective film as an optical layer. It can also be provided.

 [0051] The optical film is used for forming a liquid crystal display device such as a reflection plate, an anti-transmission plate, a retardation plate (including wavelength plates such as 1Z2 and 1Z4), a visual compensation film, and a brightness enhancement film. And an optical layer that has a problem. These can be used alone as an optical film, or can be laminated on the polarizing plate for practical use and used in one or more layers.

 [0052] In particular, a reflective polarizing plate or semi-transmissive polarizing plate in which a polarizing plate is further laminated with a reflecting plate or a semi-transmissive reflecting plate, and an elliptical polarizing plate or circular plate in which a retardation plate is further laminated on a polarizing plate. A polarizing plate, a wide viewing angle polarizing plate in which a visual compensation film is further laminated on the polarizing plate, or a polarizing plate in which a brightness enhancement film is further laminated on the polarizing plate are preferable.

[0053] A reflective polarizing plate is a polarizing plate provided with a reflective layer, and incident light from the viewing side (display side). This is for forming a liquid crystal display device of the type that reflects the light, and has the advantage that it is easy to reduce the thickness of the liquid crystal display device by omitting the incorporation of a light source such as a backlight. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer having a metal isotropic force is attached to one surface of the polarizing plate via a transparent protective layer or the like, if necessary.

 [0054] As a specific example of the reflective polarizing plate, a reflective layer is formed by attaching a foil vapor-deposited film made of a reflective metal such as aluminum on one side of a transparent protective film matted as necessary. Etc. In addition, the transparent protective film may include fine particles having a surface fine uneven structure, and a reflective layer having a fine uneven structure on the surface. The reflective layer having the fine concavo-convex structure described above has the advantage that incident light is diffused by irregular reflection to prevent directivity and glaring appearance, and to suppress unevenness in brightness and darkness. In addition, the protective film containing fine particles has an advantage that incident light and its reflected light are diffused when passing through it and light and darkness can be further suppressed. The reflective layer having a fine concavo-convex structure reflecting the surface fine concavo-convex structure of the transparent protective film can be formed by, for example, applying the metal to the surface of the transparent protective layer by an appropriate method such as a vacuum deposition method, an ion plating method, a sputtering method, or a plating method It can be performed by a method of attaching directly to the.

 [0055] Instead of the method of directly applying the reflecting plate to the transparent protective film of the polarizing plate, it is also possible to use it as a reflecting sheet in which a reflecting layer is provided on an appropriate film according to the transparent film. In addition, since the reflective layer usually has a metallic force, the usage state in which the reflective surface is covered with a transparent protective film or a polarizing plate is used to prevent the reflectance from being lowered by oxidation, and thus the long-term initial reflectance. It is more preferable in terms of sustainability and avoiding the separate provision of a protective layer.

 [0056] The transflective polarizing plate can be obtained by using a transflective reflective layer such as a half mirror that reflects and transmits light by the reflective layer. Transflective polarizing plate

Normally, it is provided on the back side of the liquid crystal cell, and when using a liquid crystal display device etc. in a relatively bright atmosphere, it reflects the incident light from the viewing side (display side) and displays an image. Under the atmosphere, it is built in the back side of the transflective polarizing plate and can be used to form liquid crystal display devices that display images using a built-in power source such as a backlight. . In other words, the transflective polarizing plate can save energy when using a light source such as a knocklight in a bright atmosphere, and can be used with a built-in power supply even in a relatively low atmosphere. It is useful for the formation of

 [0057] An elliptically polarizing plate or a circularly polarizing plate in which a retardation plate is further laminated on a polarizing plate will be described. A phase difference plate or the like is used when changing linearly polarized light into elliptically or circularly polarized light, changing elliptically or circularly polarized light into linearly polarized light, or changing the polarization direction of linearly polarized light. In particular, a so-called 1Z4 wavelength plate (also called a λλ4 plate) is used as a phase difference plate that changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. A 1Z2 wavelength plate (also referred to as λ 2 plate) is usually used to change the polarization direction of linearly polarized light.

 [0058] The elliptically polarizing plate compensates (prevents) coloring (blue or yellow) caused by double bending of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device, and displays the above-mentioned coloring! It is used effectively in such cases. Further, the one having a controlled three-dimensional refractive index is preferable because it can compensate (prevent) coloring that occurs when the screen of the liquid crystal display device is viewed from an oblique direction. The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflective liquid crystal display device in which an image is displayed in color, and also has an antireflection function.

 Examples of the retardation plate include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by the film. It is done. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 / ζ πι.

[0060] Examples of the polymer material include polybutyl alcohol, polybutyral, polymethyl vinylenoether, polyhydroxy ethino rare talylate, hydroxy ethinore cellulose, hydroxypropyl cellulose, methenorescenellose, polycarbonate, poly Allylate, Polysulfone, Polyethylene terephthalate, Polyethylene naphthalate, Polyetherolsulfone, Polyphenylene sulfide, Polyphenylene oxide, Polyallylsulfone, Polyamide, Polyimide, Polyolefin, Polychlorinated butyl, Cellulose polymer, Norbornene resin Or various types of these binary and ternary copolymers, graft copolymers, and blends. These polymer materials become an oriented product (stretched film) by stretching or the like. Examples of the liquid crystal polymer include various main chain types and side chain types in which a conjugated linear atomic group (mesogen) imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. Can be given. Specific examples of the main chain type liquid crystal polymer include a nematic orientation polyester liquid crystal polymer, a discotic polymer and a cholesteric polymer having a structure in which a mesogenic group is bonded at a spacer portion that imparts flexibility. It is done. Specific examples of side-chain liquid crystal polymers include polysiloxane, polyacrylate, polymetatalylate, or polymalonate as the main chain skeleton, and nematic alignment imparted via a spacer unit consisting of conjugated atomic groups as side chains. And those having a mesogenic moiety that is a unit force of a para-substituted cyclic compound. These liquid crystal polymers are, for example, liquid crystalline on the alignment surface such as those obtained by rubbing the surface of a thin film such as polyimide polybulal alcohol formed on a glass plate, or those obtained by obliquely vapor deposition of oxygen. This is done by developing and heat-treating the polymer solution.

 [0062] The retardation plate may have an appropriate retardation according to the purpose of use, such as for the purpose of color compensation by birefringence of various wavelength plates or liquid crystal layers, compensation of vision, etc. 2 It may be a laminate in which more than one kind of retardation plate is laminated to control optical characteristics such as retardation.

 [0063] Further, the elliptically polarizing plate and the reflective elliptical polarizing plate described above are obtained by laminating a polarizing plate or a reflective polarizing plate and a retardation plate in an appropriate combination. The elliptical polarizing plate or the like that can be formed can be formed by sequentially laminating them separately in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflection type) polarizing plate and a retardation plate. As described above, an optical film such as an elliptically polarizing plate is advantageous in that it has excellent quality stability and lamination workability, and can improve the manufacturing efficiency of a liquid crystal display device.

[0064] The visual compensation film is a film for widening the viewing angle so that the image can be seen relatively clearly even when the screen of the liquid crystal display device is viewed in a slightly oblique direction rather than perpendicular to the screen. As such a visual compensation phase difference plate, for example, a phase difference plate, an alignment film such as a liquid crystal polymer, or a support in which an alignment layer such as a liquid crystal polymer is supported on a transparent substrate can be used. A normal retardation film uses a polymer film having birefringence uniaxially stretched in the plane direction, whereas a retardation film used as a visual compensation film has a plane direction. A birefringent polymer film with birefringence and force, and a birefringent polymer or obliquely oriented film with a controlled refractive index in the thickness direction, uniaxially stretched in the plane direction and stretched in the thickness direction. Such a bi-directional stretched film is used. Examples of the tilted alignment film include a film obtained by bonding a heat-shrinkable film to a polymer film and stretching or z-shrinking the polymer film under the action of the contraction force by heating, or a film obtained by obliquely aligning a liquid crystal polymer. Etc. The raw material polymer for the phase difference plate is the same as the polymer described in the previous phase difference plate, preventing coloration due to a change in the viewing angle based on the phase difference of the liquid crystal cell and expanding the viewing angle for good viewing. Anything suitable for the purpose can be used.

 [0065] In addition, a liquid crystal polymer alignment layer, particularly an optically anisotropic layer composed of a discotic liquid crystal polymer gradient alignment layer, is supported by a triacetyl cellulose film in order to achieve a wide viewing angle with good visibility. The optically compensated retardation plate can be preferably used.

[0066] A polarizing plate obtained by bonding a polarizing plate and a brightness enhancement film is usually used by being provided on the back side of the liquid crystal cell. The brightness enhancement film reflects the linearly polarized light with a predetermined polarization axis or circularly polarized light in a predetermined direction when natural light is incident due to a backlight of a liquid crystal display device or the like, or reflection from the back side, and transmits other light. Thus, a polarizing plate in which a brightness enhancement film is laminated with a polarizing plate allows light from a light source such as a backlight to be incident to obtain transmitted light in a predetermined polarization state, and reflects light without transmitting the light other than the predetermined polarization state. Is done. The light reflected on the surface of the brightness enhancement film is further inverted through a reflective layer provided behind the brightness enhancement film and re-incident on the brightness enhancement film, and part or all of the light is transmitted as light having a predetermined polarization state. In addition to increasing the amount of light transmitted through the brightness enhancement film, it is possible to improve the brightness by supplying polarized light that is not easily absorbed by the polarizer and increasing the amount of light that can be used for liquid crystal display image display, etc. is there. That is, when light is incident through the polarizer behind the liquid crystal cell without using a brightness enhancement film, the light having a polarization direction that does not coincide with the polarization axis of the polarizer is It is almost absorbed by the polarizer and does not pass through the polarizer. That is, approximately 50% of the light that is different depending on the characteristics of the polarizer used is absorbed by the polarizer, and the amount of light that can be used for liquid crystal image display is reduced, and the image becomes dark. The brightness enhancement film has a polarization that is absorbed by the polarizer. It is repeated that the light having the light direction is reflected once by the brightness enhancement film without being incident on the polarizer, and is further reversed through the reflective layer provided on the back side and re-incident on the brightness enhancement film. The brightness enhancement film transmits only the polarized light whose polarization direction is reflected and reversed between the two so that it can pass through the polarizer, and is supplied to the polarizer. Light can be efficiently used to display images on a liquid crystal display device, and the screen can be brightened.

 [0067] A diffusion plate may be provided between the brightness enhancement film and the reflective layer. The polarized light reflected by the brightness enhancement film is directed to the reflection layer and the like, but the installed diffuser diffuses the light passing therethrough at the same time and simultaneously cancels the polarization state to become a non-polarized state. That is, the light in the natural light state is directed to the reflection layer and the like, is reflected through the reflection layer and the like, passes through the diffusion plate again, and reenters the brightness enhancement film. In this way, by providing a diffuser plate that returns polarized light to the original natural light between the brightness enhancement film and the reflective layer, the brightness of the display screen is maintained, and at the same time, uneven brightness of the display screen is reduced. Can provide a uniform and bright screen. By providing a powerful diffuser, the number of repetitions of the initial incident light increased moderately, and combined with the diffusion function of the diffuser, it was possible to provide a uniform brightness V and display screen. It is done.

 [0068] As the brightness enhancement film, for example, a dielectric multilayer thin film or a multilayer laminate of thin film films having different refractive index anisotropies transmits linearly polarized light having a predetermined polarization axis and transmits other light. Reflecting one of the left-handed or right-handed circularly polarized light and transmitting the other light, such as those that show reflective properties, such as oriented films of cholesteric liquid crystal polymer and those oriented liquid crystal layers supported on a film substrate Appropriate things such as those showing the characteristics to be used can be used.

[0069] Therefore, in the type of brightness enhancement film that transmits linearly polarized light having the predetermined polarization axis described above, the transmitted light is directly incident on the polarizing plate with the polarization axis aligned, thereby suppressing absorption loss due to the polarizing plate. However, it can be transmitted efficiently. On the other hand, in a brightness enhancement film of a type that transmits circularly polarized light such as a cholesteric liquid crystal layer, it can be directly incident on a polarizer. However, the circularly polarized light is linearly polarized through a retardation plate in order to suppress absorption loss. It is preferable to make it light and make it enter into a polarizing plate. Note that circularly polarized light can be converted to linearly polarized light by using a 1Z4 wavelength plate as the retardation plate. [0070] A retardation plate that functions as a 1Z4 wavelength plate at a wide wavelength such as in the visible light region exhibits, for example, a retardation plate that functions as a 1Z4 wavelength plate for light-colored light having a wavelength of 55 Onm and other retardation characteristics. It can be obtained by a method of superposing a retardation layer, for example, a retardation layer functioning as a 1Z2 wavelength plate. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may have a retardation layer force of one layer or two or more layers.

 [0071] Note that the cholesteric liquid crystal layer also reflects circularly polarized light in a wide wavelength range such as a visible light castle by combining two or more layers with different reflection wavelengths in an overlapping structure. Based on this, transmission circular polarization in a wide and wavelength range can be obtained.

 [0072] The polarizing plate may be formed by laminating a polarizing plate such as the above-described polarization-separating polarizing plate and two or more optical layers. Therefore, a reflective elliptical polarizing plate or a semi-transmissive elliptical polarizing plate in which the above-mentioned reflective polarizing plate or semi-transmissive polarizing plate and a retardation plate are combined may be used.

 [0073] An optical film in which the optical layer is laminated on a polarizing plate can be formed even in a method of laminating separately in the manufacturing process of a liquid crystal display device or the like. It has excellent quality stability and assembly work! /, And has the advantage of improving the manufacturing process of liquid crystal display devices. For the lamination, an appropriate adhesive means such as an adhesive layer can be used. When the polarizing plate and the other optical layer are bonded, their optical axes can be arranged at an appropriate angle depending on the target retardation characteristics.

Next, a method for producing an antistatic pressure-sensitive adhesive optical film will be described.

On the optical film 1 described above, a dispersion liquid containing a carbon nanomaterial, a binder component, a dispersant, and the like is applied and dried to form the antistatic layer 2. The solid content concentration of the dispersion is preferably adjusted to about 0.05 to 50% by weight. Examples of the coating method include a roll coating method such as reverse coating and gravure coating, a spin coating method, a screen coating method, a fountain coating method, a dating method, and a spray method.

[0076] The thickness of the antistatic layer is preferably 5 to: LOOOnm. The thickness of the antistatic layer is usually 5000 nm or less, and the point of reduction in optical properties is usually less, but the thickness of the antistatic layer increases. If the antistatic layer is not strong enough, the antistatic layer may break down and may not have sufficient adhesion. The thickness of the antistatic agent is preferably 500 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. In order to ensure adhesion and suppress peeling charge, it is preferably 5 nm or more, and more preferably lOnm or more. On the other hand, the peeling charge effect is preferably that the antistatic layer is thicker, but it is less than or equal to 200 nm. From this point, it is preferable that the thickness is 5 to 500 nm, further 10 to 300 nm, and further 10 to 200 nm.

 [0077] In forming the antistatic layer 2, the optical film 1 can be subjected to an activation treatment.

 Various methods can be employed for the active soot treatment, such as corona treatment, low-pressure UV treatment, plasma treatment, and the like. The activation treatment is effective when an aqueous solution containing a water-soluble conductive polymer is used as an antistatic agent, and repelling when applying the aqueous solution can be suppressed. The activation treatment is effective particularly when the optical film 1 is a polyolefin resin or a norbornene resin.

 The pressure-sensitive adhesive layer 3 is formed by laminating on the antistatic layer 2. The forming method is not particularly limited, and examples thereof include a method of applying a pressure-sensitive adhesive solution to the antistatic layer and drying, a method of transferring with a release sheet provided with a pressure-sensitive adhesive layer, and the like. The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably about 10 to 40 μm.

 [0079] Constituent materials of the release film include paper, polyethylene, polypropylene, synthetic resin films such as polyethylene terephthalate, rubber sheets, paper, cloth, non-woven fabrics, nets, foam sheets, metal foils, laminates thereof, and the like. Appropriate thin leaves and the like can be mentioned. The surface of the release film is subjected to low-adhesive release treatments such as silicone treatment, long-chain alkyl treatment, and fluorine treatment as necessary to improve the peelability from the pressure-sensitive adhesive layer 3! Also good!

[0080] It should be noted that each layer such as an optical film or an adhesive layer of the antistatic adhesive optical film of the present invention includes, for example, a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, and a cyanoacrylate compound. Further, it may be one having an ultraviolet absorbing ability by a method such as a method of treating with an ultraviolet absorber such as a nickel complex compound.

[0081] The adhesion between the antistatic layer 2 and the pressure-sensitive adhesive layer 3 is as follows. The peeling angle is 180 ° and the peeling speed is 300 mm. It is preferable that the Zmin is 10 NZ25 mm or more, more preferably 15 NZ25 mm or more. If the adhesive strength is less than 10NZ25mm, adhesive residue may be generated when the optical film is peeled off from the liquid crystal panel, or peeling may occur in a heated and humidified environment.

 [0082] The antistatic pressure-sensitive adhesive optical film of the present invention can be preferably used for forming various image display devices such as liquid crystal display devices. The liquid crystal display device can be formed according to the conventional method. In other words, a liquid crystal display device generally has a force formed by appropriately assembling components such as a liquid crystal cell, an antistatic adhesive optical film, and an illumination system as necessary, and incorporating a drive circuit. The method can be based on the conventional method without any limitation except that the optical film according to the present invention is used. As the liquid crystal cell, for example, any type such as a TN type, STN type, or π type can be used.

 [0083] An appropriate liquid crystal display device such as a liquid crystal display device in which an antistatic adhesive optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight in a lighting system or a reflector is formed. Can do. In that case, the optical film according to the present invention can be placed on one or both sides of the liquid crystal cell. When optical films are provided on both sides, they may be the same or different. Further, when forming a liquid crystal display device, for example, a single layer of appropriate parts such as a diffuser plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, and a knocklight at an appropriate position. Or two or more layers can be arranged.

Next, an organic electroluminescence device (organic EL display device) will be described. The optical film (polarizing plate or the like) of the present invention can also be applied to an organic EL display device. In general, in an organic EL display device, a transparent electrode, an organic light emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light emitter (organic electroluminescent light emitter). Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injecting layer having an isotropy such as a triphenylamine derivative and a light emitting layer having a fluorescent organic solid force such as anthracene. Or a laminate of such a light emitting layer and a perylene derivative or the like electron injection layer, or a stack of these hole injection layer, light emitting layer, and electron injection layer. The composition is known. [0085] In an organic EL display device, by applying a voltage to a transparent electrode and a metal electrode, holes and electrons are injected into the organic light emitting layer, and the energy generated by recombination of these holes and electrons is the same. Emits light on the principle that it excites the fluorescent material and emits light when the excited fluorescent material returns to the ground state. The mechanism of recombination in the middle is the same as that of a general diode, and as can be expected from this, the current and emission intensity show strong nonlinearity with rectification with respect to the applied voltage.

 [0086] In an organic EL display device, in order to extract light emitted from the organic light emitting layer, at least one of the electrodes must be transparent, and is usually formed of a transparent conductor such as indium tin oxide (ITO). A transparent electrode is used as the anode. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material with a low work function for the cathode, and usually metal electrodes such as Mg Ag and A1-Li are 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 1 Onm. For this reason, the organic light emitting layer transmits light almost completely like the transparent electrode. As a result, light that is incident on the surface of the transparent substrate when not emitting light, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode again returns to the surface side of the transparent substrate. When viewed, the display surface of the OLED display looks like a mirror.

 [0088] In an organic EL display device including an organic electroluminescent light emitting device including a transparent electrode on a front surface side of an organic light emitting layer that emits light by application of a voltage and a metal electrode on a back surface side of the organic light emitting layer, A polarizing plate can be provided on the surface side of the electrode, and a retardation plate can be provided between the transparent electrode and the polarizing plate.

 [0089] Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization function. is there. In particular, if the retardation plate is a 1Z4 wavelength plate and the angle between the polarization directions of the polarizing plate and the retardation plate is adjusted to π Z4, the mirror surface of the metal electrode can be completely shielded.

That is, only the linearly polarized light component of the external light incident on the organic EL display device is transmitted through the polarizing plate. This linearly polarized light is generally elliptically polarized by the phase difference plate. However, the phase difference plate is a 1Z4 wavelength plate, and the angle between the polarization direction of the polarizing plate and the phase difference plate is π Ζ4. Sometimes circularly polarized.

 [0091] This circularly polarized light is transmitted through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, is again transmitted through the organic thin film, the transparent electrode, and the transparent substrate, and is linearly polarized again on the retardation plate. Become. And since this linearly polarized light is orthogonal to the polarization direction of the polarizing plate, it cannot be transmitted through the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

 Example

 [0092] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, all parts and percentages are based on weight.

 [0093] (Preparation of polarizing plate)

 A polybulal alcohol film having a thickness of 80 μm was stretched 5 times in an aqueous iodine solution at 40 ° C, and then dried at 50 ° C for 4 minutes to obtain a polarizer. A polarizing plate was obtained by adhering a triacetyl cellulose film on both sides of the polarizer using a polybulal alcohol adhesive.

 [0094] Example 1

 (Formation of antistatic layer)

 100 parts of isopropyl alcohol solvent, 0.2 part of carbon nanotubes, 20 parts of polyester resin aqueous dispersion (manufactured by Nagase ChemteX Corporation, Kabusen ES-210, solid content 25%) as binder component, and polyvinylpyrrolidone as dispersant (Weight average molecular weight: 50000) 2 parts were added and sonication was performed for 30 minutes to prepare a dispersion. The dispersion was applied to one side of the polarizing plate so that the thickness after drying was 50 nm, and dried at 80 ° C. for 2 minutes to form an antistatic layer.

[0095] (Formation of adhesive layer)

As a base polymer, 95 parts of butyl acrylate, 5 parts of acrylic acid and 0.2 part of benzoyl peroxide are dissolved in 300 parts of ethyl acetate and reacted at about 60 ° C for 6 hours with stirring to obtain an average molecular weight of 2 million. A solution (20% solid content) containing an acrylic polymer was used. To the above acrylic polymer solution, 0.5 part of Coronate L manufactured by Nippon Polyurethane Co., Ltd., which is an isocyanate-based polyfunctional compound, was added to 100 parts of polymer solid content. The pressure-sensitive adhesive solution is separated from a release film (Mitsubishi Chemical Polyester, Die, so that the thickness after drying is 25 m. After applying it by reverse roll coating method, it is further coated with a release film and dried in a hot air circulation oven.

A pressure-sensitive adhesive layer was formed.

[0096] (Preparation of antistatic adhesive optical film)

 On the antistatic layer of the antistatic polarizing plate, a release film on which an adhesive layer was formed was bonded to prepare an antistatic adhesive polarizing plate.

[0097] Example 2

 In the formation of the antistatic layer of Example 1, an antistatic pressure-sensitive adhesive polarizing plate was produced in the same manner as in Example 1 except that 2 parts of carbon nanotubes were added.

[0098] Comparative Example 1

 An antistatic pressure-sensitive adhesive polarizing plate was produced in the same manner as in Example 1 except that carbon nanotubes were not added in the formation of the antistatic layer of Example 1.

[0099] Comparative Example 2

 In the formation of the antistatic layer of Example 1, an antistatic adhesive polarizing plate was prepared in the same manner as in Example 1 except that 1 part of carbon black was added instead of carbon nanotubes.

[0100] Comparative Example 3

 (Formation of antistatic layer)

 Dispersion containing tin oxide fine particles (Yamanaka Sangyo Co., Ltd., EPS 6) was applied to one side of the polarizing plate so that the thickness after drying was 200 nm, and dried at 80 ° C for 2 minutes to charge. A protective layer was formed.

[0101] (Preparation of antistatic adhesive optical film)

 An antistatic pressure-sensitive adhesive polarizing plate was produced in the same manner as in Example 1.

[0102] The antistatic pressure-sensitive adhesive optical films obtained in Examples and Comparative Examples were evaluated as follows. Table 1 shows the evaluation results.

[0103] [Light transmittance]

The produced antistatic pressure-sensitive adhesive optical film was punched out to a size of 25 mm × 50 mm with a Thomson blade type, and bonded to the glass surface to obtain a sample. Integral sphere spectral transmission The light transmittance of the sample was measured using a rate measuring device (DOT-3, manufactured by Murakami Color Research Laboratory Co., Ltd.).

 [Antistatic effect]

 The produced antistatic adhesive optical film was cut into a size of 100 mm X 100 mm and attached to a liquid crystal panel. This panel was placed on a backlight with a brightness of lOOOOcd, and 5kv of static electricity was generated using ESD (SANKI, ESD-8012A), a static electricity generator, which caused liquid crystal alignment disorder. . The recovery time (seconds) for the display failure due to the orientation failure was measured using an instantaneous multiphotometric detector (MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.). The panel was allowed to stand for 500 hours in a 50 ° C environment, and then the recovery time (seconds) was measured in the same manner as described above.

[Table 1] Light transmittance Display failure recovery time (S)

 (%) Before heating After heating Example 1 43.5 <1 <1

 Example 2 43.4 <1 <1

 Comparative Example 1 43.5> 1800> 1800

 Comparative Example 2 42.8 <1 + 1

 Comparative Example 3 43.4 <1> 1800

Claims

The scope of the claims

 [1] An antistatic layer is laminated on at least one surface of the optical film, and an adhesive layer is further laminated on the antistatic layer, and the antistatic layer contains a carbon nanomaterial. Preventive adhesive optical film.

 2. The antistatic pressure-sensitive adhesive optical film according to claim 1, wherein the carbon nanomaterial is a carbon nanotube.

 3. The antistatic pressure-sensitive adhesive optical film according to claim 1, wherein the antistatic layer further contains a binder component.

 4. The antistatic pressure-sensitive adhesive optical film according to claim 3, wherein the noinder component is at least one selected from the group consisting of polyurethane-based resin, polyester-based resin and acrylic-based resin.

 5. The antistatic pressure-sensitive adhesive optical film according to claim 1, wherein the antistatic layer further contains a dispersant.

 6. The antistatic pressure-sensitive adhesive optical film according to claim 1, wherein the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive.

 [7] A method for producing an antistatic pressure-sensitive adhesive optical film according to claim 1, wherein a dispersion containing a carbon nanomaterial is applied to at least one surface of the optical film and dried to form an antistatic layer. A method for producing an antistatic pressure-sensitive adhesive optical film, comprising a step of forming and a step of forming an adhesive layer on the antistatic layer.

 [8] An image display device using at least one antistatic adhesive optical film according to any one of [1] to [6].