JP2006201337A - Adhesive optical film and image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive optical film at least with its one side laminated with an adhesive layer, which is excellent in rework performance. <P>SOLUTION: The optical film at least its one side is laminated with the adhesive layer, wherein the adhesive layer is laminated through the anchor layer formed of silane coupling agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an adhesive optical film in which an adhesive layer is laminated on at least one surface of an optical film. Furthermore, the present invention relates to an image display device such as a liquid crystal display device, an organic EL display device, and a PDP using the 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.

  In a liquid crystal display or the like, it is indispensable to dispose polarizing elements on both sides of a liquid crystal cell because of its image forming method, and generally a polarizing plate is attached. In addition to polarizing plates, various optical elements have been used for liquid crystal panels in order to improve the display quality of displays. For example, a retardation plate for preventing coloring of an oblique field of view, 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.

  When sticking the optical film on a liquid crystal cell, an adhesive is usually used. In addition, the adhesive between the optical film and the liquid crystal cell and the optical film is usually in close contact with each other using an adhesive to reduce the loss of light. In such a case, since the adhesive has the merit that a drying step is not required to fix the optical film, the adhesive is an adhesive optical film provided in advance as an adhesive layer on one side of the optical film. Generally used.

  The required properties required for the pressure-sensitive adhesive include: (1) When an optical film is bonded to the surface of a liquid crystal panel, the optical film can be used even when the bonding position is wrong or a foreign object is caught in the bonding surface. Can be peeled off from the surface of the liquid crystal panel and re-bonded (rework) is possible, (2) has stress relaxation properties to prevent optical unevenness caused by dimensional changes of the optical film, and (3) an environmental promotion test For example, a defect caused by the pressure-sensitive adhesive does not occur with respect to a durability test that is usually performed by heating and humidification.

  In particular, with regard to the reworkability of (1) above, in the conventional adhesive optical film, since the adhesiveness between the adhesive layer and the optical film substrate is low, when peeling the adhesive optical film from the liquid crystal panel, There has been a problem that a part of the pressure-sensitive adhesive of the pressure-sensitive optical film remains on the surface of the liquid crystal panel (hereinafter referred to as pressure-sensitive adhesive residue).

As an adhesive optical film that solves such problems, for example, a film in which polyethyleneimine is provided as an anchor layer and an adhesive layer is laminated therethrough has been proposed (Patent Document 1). In recent years, a pressure-sensitive adhesive optical film with good adhesiveness and no adhesive remaining has been desired for reworkability.
JP 2004-78143 A

  An object of the present invention is to provide a pressure-sensitive adhesive optical film in which a pressure-sensitive adhesive layer is laminated on at least one surface of an optical film, and has good reworkability.

  Another object of the present invention is to provide an image display device using the adhesive optical film.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by the following pressure-sensitive adhesive optical film, and have completed the present invention.

That is, the present invention is an adhesive optical film in which an adhesive layer is laminated on at least one surface of the optical film,
The pressure-sensitive adhesive layer relates to a pressure-sensitive adhesive optical film, wherein the pressure-sensitive adhesive layer is laminated via an anchor layer formed of a silane coupling agent.

  The pressure-sensitive adhesive optical film of the present invention is considered to be mainly due to low adhesion between the pressure-sensitive adhesive layer and the optical film substrate, and the silane coupling agent between the pressure-sensitive adhesive layer and the optical film substrate. By interposing the anchor layer formed by the above, the adhesiveness between the pressure-sensitive adhesive layer and the optical film is improved, and the pressure-sensitive adhesive residue is reduced.

  In the pressure-sensitive adhesive optical film, the silane coupling agent is preferably an amino group-containing silane coupling agent. The anchor layer formed by the amino group-containing silane coupling agent is a silane layer having an amino group, and the amino group in the anchor layer is bonded to the functional group in the adhesive layer at and near the interface of the adhesive layer. It reacts and an anchor layer and an adhesive layer can adhere | attach firmly.

  In the pressure-sensitive adhesive optical film, the pressure-sensitive adhesive layer is preferably formed of an acrylic pressure-sensitive adhesive.

  For the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, it is preferable to use a base polymer containing a functional group that reacts with an amino group. By using a polymer containing a functional group that reacts with an amino group as the base polymer, an amino group and a pressure-sensitive adhesive are formed at and near the interface between the anchor layer and the pressure-sensitive adhesive layer formed by the amino group-containing silane coupling agent. The functional group in the layer reacts, and the anchor layer and the pressure-sensitive adhesive layer adhere firmly.

  In the pressure-sensitive adhesive optical film, it is preferable that the functional group that reacts with the amino group contained in the base polymer of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is a carboxyl group. The carboxyl group has good reactivity with the amino group, is suitable as a functional group contained in the base polymer, and has good adhesion between the pressure-sensitive adhesive layer and the anchor layer.

  In the pressure-sensitive adhesive optical film, triacetyl cellulose, norbornene-based resin or polycarbonate can be suitably used as the material for the optical film surface on which the anchor layer is laminated.

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

  The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive optical film of the present invention is not particularly limited, and various pressure-sensitive adhesives such as a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive can be used. In general, an acrylic pressure-sensitive adhesive having good adhesion to a liquid crystal cell or the like is used. The base polymer of the pressure-sensitive adhesive preferably has a functional group that reacts with an amino group.

  The acrylic pressure-sensitive adhesive has an acrylic polymer having a main skeleton of an alkyl (meth) acrylate monomer unit as a base polymer. (Meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning. The average carbon number of the alkyl group of the alkyl (meth) acrylate constituting the main skeleton of the acrylic polymer is about 1 to 12, and specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (Meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and the like can be exemplified, and these can be used alone or in combination. Among these, alkyl (meth) acrylates having 1 to 7 carbon atoms in the alkyl group are preferable.

  Examples of the functional group that reacts with the amino group introduced into the base polymer such as the acrylic polymer include a carboxyl group, an epoxy group, and an isocyanate group. Of these, a carboxyl group is preferred. The acrylic polymer having a functional group that reacts with an amino group contains a monomer unit having the functional group. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, and itaconic acid. Examples of the monomer containing an epoxy group include glycidyl (meth) acrylate.

  The ratio of the monomer unit (a) having the functional group in the acrylic polymer is not particularly limited, but the weight with respect to the monomer unit (A) constituting the acrylic polymer (excluding the monomer unit (a)). The ratio (a / A) is preferably about 0.001 to 0.12, more preferably 0.005 to 0.1.

  In addition, a monomer unit having a hydroxyl group, a monomer unit having an N element, and the like can be introduced into the acrylic polymer. In particular, monomer units having a hydroxyl group are preferred. Examples of the monomer having a hydroxyl group include a hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate and N-methylol (meth) acrylamide, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate and the like. N element-containing monomers include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, (meth) acryloylmorpholine, (meth) acetonitrile, vinylpyrrolidone, N-cyclohexylmaleimide Itaconimide, N, N-dimethylaminoethyl (meth) acrylamide and the like. In addition, as the acrylic polymer, vinyl acetate, styrene, or the like can be used as long as the performance of the pressure-sensitive adhesive is not impaired. These monomers can be used alone or in combination of two or more.

  The average molecular weight of the acrylic polymer is not particularly limited, but the weight average molecular weight (GPC) 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 bulk polymerization method, a solution polymerization method, or a suspension polymerization method can be appropriately selected. As the radical polymerization initiator, various known azo and peroxide compounds can be used, and the reaction temperature is usually about 50 to 85 ° C. and the reaction time is about 1 to 8 hours. Among the above production methods, the solution polymerization method is preferable, and a polar solvent such as ethyl acetate or toluene is generally used as the solvent for the acrylic polymer. The solution concentration is usually about 20 to 80% by weight.

  Examples of the base polymer of the rubber adhesive include natural rubber, isoprene rubber, styrene-butadiene rubber, recycled rubber, polyisobutylene rubber, styrene-isoprene-styrene rubber, and styrene-butadiene-styrene rubber. Examples of the base polymer of the silicone-based pressure-sensitive adhesive include dimethylpolysiloxane, diphenylpolysiloxane, and the like, in which functional groups having reactivity with amino groups such as carboxyl groups are introduced. It can be used suitably.

  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 the organic crosslinking agent include an epoxy crosslinking agent, an isocyanate crosslinking agent, and an imine crosslinking agent. As the organic crosslinking agent, an isocyanate crosslinking agent is preferable. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. can give. Examples of the atom in the organic compound that is covalently bonded or coordinated include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound.

  The blending ratio of the base polymer such as an acrylic polymer and the crosslinking agent is not particularly limited, but is usually preferably about 0.01 to 10 parts by weight of the crosslinking agent (solid content) with respect to 100 parts by weight of the base polymer (solid content). Furthermore, about 0.1-6 weight part is preferable.

  Furthermore, the pressure-sensitive adhesive may include a tackifier, a plasticizer, glass fiber, glass beads, metal powder, other inorganic powders, a pigment, a colorant, a filler, an antioxidant, if necessary. Various additives may be used as appropriate, such as an agent, an ultraviolet absorber, a silane coupling agent, and the like 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.

  As the silane coupling agent for forming the anchor layer, those capable of forming a coating film can be used without particular limitation. As the silane coupling agent, those capable of forming an anchor layer capable of improving the wettability and adhesiveness of the optical film are preferable. In addition to the silane coupling agent, a titanate coupling agent having a hydrolyzable hydrophilic group containing titanium and an organic functional group in the same molecule, a hydrolyzable hydrophilic containing aluminum in the same molecule. Other coupling agents such as aluminate coupling agents having functional groups and organic functional groups, and resins having organic reactive groups such as epoxy resins, isocyanate resins and urethane resins on the optical film surface The anchor layer can be formed by a method such as coating, but the silane coupling agent is preferably moisture resistant, weather resistant, heat resistant, transparent, etc., compared to these. A silane coupling agent is also preferable from the viewpoint of easy handling industrially.

  The silane coupling agent usually has, for example, a reactive functional group such as an amino group, a vinyl group, an epoxy group, a mercapto group, or a chloro group and a hydrolyzable alkoxysilyl group in the same molecule. The silane layer is formed by hydrolysis. Among such silane coupling agents, those having an amino group are preferable.

  Specific examples of the silane coupling agent include isocyanate group-containing alkoxysilanes such as γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, and γ-isocyanatopropylmethyldimethoxysilane. Γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) amino Propylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ-ureidopropyltrimethoxysila Amino group-containing alkoxysilanes such as N-phenyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltriethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane; γ-mercaptopropyl Mercapto group-containing alkoxysilanes such as trimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycol Sidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysila Epoxy group-containing alkoxysilanes such as β-carboxyethyltriethoxysilane, β-carboxyethylphenylbis (2-methoxyethoxy) silane, N-β- (stroxymethyl) aminoethyl-γ-aminopropyltrimethoxylane, etc. Carboxy-containing alkoxysilanes; vinyl-type unsaturated group-containing alkoxysilanes such as vinylmethoxysilane, vinyltriethoxysilane, γ-acryloyloxypropylmethyltriethoxysilane; halogens such as γ-chloropropyltrimethoxysilane Group-containing alkoxysilanes; tris (trimethoxysilyl) isocyanurate group-containing alkoxysilanes, amino-modified silyl polymers, silylated amino polymers, unsaturated aminosilane complexes, phenylamino long-chain alkylsilanes, aminosilylated silyls Examples include corn, silylated polyester, and derivatives thereof.

  In forming the anchor layer, an additive such as a reaction accelerator can be added to the silane coupling agent.

  In the pressure-sensitive adhesive optical film of the present invention, as shown in FIG. 1, a pressure-sensitive adhesive layer 3 is provided on an optical film 1 via an anchor layer 2 formed of a silane coupling agent. A release sheet 4 can be provided on the pressure-sensitive adhesive layer 3.

  As the optical film used in the 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 kind thereof is not particularly limited. For example, the optical film includes a polarizing plate. A polarizing plate having a transparent protective film on one or both sides of a polarizer is generally used. The transparent protective film itself becomes an optical film.

  The polarizer is not particularly limited, and various types can be used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

  A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be prepared by, for example, dying polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution of boric acid or potassium iodide or in a water bath.

  As a material for forming the transparent protective film provided on one side 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 polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) -Based polymer, polycarbonate-based polymer and the like. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Polymer blends and the like are also examples of polymers that form the transparent protective film. 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.

  Moreover, the polymer film described in JP-A-2001-343529 (WO01 / 37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and (B) a substitution in the side chain And / or a resin composition containing a thermoplastic resin having unsubstituted phenyl and a nitrile group. A specific example is a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of the resin composition or the like can be used.

  Although the thickness of a protective film can be determined suitably, generally it is about 1-500 micrometers from points, such as workability | operativity, such as intensity | strength and handleability, and thin film property. In particular, 5 to 200 μm is preferable.

  Moreover, it is preferable that a protective film has as little color as possible. 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 direction retardation 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, coloring (optical coloring) of the polarizing plate caused by the protective film can be almost eliminated. The thickness direction retardation (Rth) is more preferably -80 nm to +60 nm, and particularly preferably -70 nm to +45 nm.

  As the protective film, a cellulose polymer such as triacetyl cellulose is preferable from the viewpoints of polarization characteristics and durability. A triacetyl cellulose film is particularly preferable. In addition, when providing a protective film on both sides of a polarizer, the protective film which consists of the same polymer material may be used by the front and back, and the protective film which consists of a different polymer material etc. 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 the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester.

  The surface of the transparent protective film to which the polarizer is not adhered may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.

  The hard coat treatment is applied for the purpose of preventing scratches on the surface of the polarizing plate. For example, a transparent protective film with a cured film excellent in hardness, sliding properties, etc. by an appropriate ultraviolet curable resin such as acrylic or silicone is used. It can be formed by a method of adding to the surface of the film. 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. Further, the sticking prevention treatment is performed for the purpose of preventing adhesion between adjacent layers of other members.

  Anti-glare treatment is applied for the purpose of preventing external light from being reflected on the surface of the polarizing plate and obstructing the visibility of the light transmitted through the polarizing plate. For example, the surface is roughened by sandblasting or embossing. 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 method or a compounding method of transparent fine particles. Examples of the fine particles to be included in the formation of the surface fine concavo-convex structure include conductive materials made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, and the like having an average particle diameter of 0.5 to 50 μm. In some cases, transparent fine particles such as inorganic fine particles and organic fine particles (including beads) made of a crosslinked or uncrosslinked polymer are used. When forming a surface fine uneven structure, the amount of fine particles used is generally about 2 to 50 parts by weight, preferably 5 to 25 parts by weight, based on 100 parts by weight of the transparent resin forming the surface fine uneven structure. 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.

  The antireflection layer, antisticking layer, diffusion layer, antiglare layer, and the like can be provided on the transparent protective film itself, or can be provided separately from the transparent protective film as an optical layer.

  In addition, as an optical film, for example, it 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 1/2 and 1/4), a visual compensation film, and a brightness enhancement film. And an optical layer that may be formed. These can be used alone as an optical film, or can be laminated on the polarizing plate for practical use and used as one layer or two or more layers.

  In particular, a reflective polarizing plate or a semi-transmissive polarizing plate in which a polarizing plate is further laminated with a reflecting plate or a semi-transmissive reflecting plate, an elliptical polarizing plate or a circular polarizing 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 a plate, or a polarizing plate in which a luminance enhancement film is further laminated on a polarizing plate is preferable.

  A reflective polarizing plate is a polarizing plate provided with a reflective layer, and is used to form a liquid crystal display device or the like that reflects incident light from the viewing side (display side). Such a light source can be omitted, and the liquid crystal display device can be easily thinned. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is attached to one surface of the polarizing plate via a transparent protective layer or the like as necessary.

  Specific examples of the reflective polarizing plate include those in which a reflective layer is formed by attaching a foil or a vapor deposition film made of a reflective metal such as aluminum on one side of a transparent protective film matted as necessary. In addition, the transparent protective film may contain fine particles to form a surface fine concavo-convex structure, and a reflective layer having a fine concavo-convex structure thereon. The reflective layer having the fine concavo-convex structure has an advantage that incident light is diffused by irregular reflection to prevent directivity and glaring appearance and to suppress unevenness in brightness and darkness. Moreover, the protective film containing fine particles also has an advantage that incident light and its reflected light are diffused when passing through it and light and dark unevenness can be further suppressed. The reflective layer of the fine concavo-convex structure reflecting the surface fine concavo-convex structure of the transparent protective film is formed by, for example, applying 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 screen.

  Instead of the method of directly applying the reflecting plate to the transparent protective film of the polarizing plate, the reflecting plate can be used as a reflecting sheet provided with a reflecting layer on an appropriate film according to the transparent film. Since the reflective layer is usually made of metal, the usage form in which the reflective surface is covered with a transparent protective film, a polarizing plate or the like is used to prevent the reflectance from being lowered due to oxidation, and thus to maintain the initial reflectance for a long time. In addition, it is more preferable to avoid a separate attachment of the protective layer.

  The semi-transmissive polarizing plate can be obtained by using a semi-transmissive reflective layer such as a half mirror that reflects and transmits light with the reflective layer. A transflective polarizing plate is usually provided on the back side of a liquid crystal cell, and displays an image by reflecting incident light from the viewing side (display side) when a liquid crystal display device is used in a relatively bright atmosphere. In a relatively dark atmosphere, a liquid crystal display device of a type that displays an image using a built-in power source such as a backlight built in the back side of the transflective polarizing plate can be formed. In other words, the transflective polarizing plate can be used to form liquid crystal display devices that can save energy when using a light source such as a backlight in a bright atmosphere and can be used with a built-in power supply even in a relatively dark atmosphere. It is.

  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 to elliptically polarized light or circularly polarized light, changing elliptically polarized light or circularly polarized light to linearly polarized light, or changing the polarization direction of linearly polarized light. In particular, a so-called quarter-wave plate (also referred to as a λ / 4 plate) is used as a retardation plate that changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. A half-wave plate (also referred to as a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

  The elliptically polarizing plate is effectively used for black and white display without the above color by compensating (preventing) the coloration (blue or yellow) generated by the birefringence of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device. It is done. Further, the one in which the three-dimensional refractive index is controlled 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 a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm.

  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, polyallylsulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, norbornene resin, or binary, ternary copolymers, graft copolymers, Examples include 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. . Specific examples of the main chain type liquid crystal polymer include a nematic alignment polyester liquid crystal polymer, a discotic polymer, and a cholesteric polymer having a structure in which a mesogen group is bonded at a spacer portion that imparts flexibility. Specific examples of the side chain type liquid crystal polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a nematic alignment-providing para-substitution through a spacer portion composed of a conjugated atomic group as a side chain. Examples thereof include those having a mesogenic part composed of a cyclic compound unit. These liquid crystal polymers are prepared by, for example, applying a solution of a liquid crystalline polymer on an alignment treatment surface such as a surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or an oblique deposition of silicon oxide. This is done by developing and heat treatment.

  The retardation plate may have an appropriate retardation according to the purpose of use, such as for the purpose of compensating for coloring, vision, etc. due to birefringence of various wave plates and liquid crystal layers, and may be two or more types. It may be one in which retardation plates are stacked and optical characteristics such as retardation are controlled.

  The elliptical polarizing plate and the reflective elliptical polarizing plate are obtained by laminating a polarizing plate or a reflective polarizing plate and a retardation plate in an appropriate combination. Such an elliptically polarizing plate or the like can also be formed by sequentially laminating them sequentially in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflective) polarizing plate and a retardation plate. An optical film such as a polarizing plate has an advantage that it can improve the production efficiency of a liquid crystal display device and the like because of excellent quality stability and lamination workability.

  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 from a slightly oblique direction rather than perpendicular to the screen. Examples of such a visual compensation phase difference plate include a phase difference plate, an alignment film such as a liquid crystal polymer, and a film in which an alignment layer such as a liquid crystal polymer is supported on a transparent substrate. A normal retardation plate uses a birefringent polymer film that is uniaxially stretched in the plane direction, whereas a retardation plate used as a visual compensation film is biaxially stretched in the plane direction. Birefringent polymer film, biaxially stretched film such as polymer with birefringence with a controlled refractive index in the thickness direction that is uniaxially stretched in the plane direction and stretched in the thickness direction, etc. Used. Examples of the inclined alignment film include a film obtained by bonding a heat shrink film to a polymer film and stretching or / and shrinking the polymer film under the action of the contraction force by heating, and a film obtained by obliquely aligning a liquid crystal polymer. can give. 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 by the liquid crystal cell and expanding the viewing angle for good visual recognition. An appropriate one for the purpose can be used.

  In addition, from the viewpoint of achieving a wide viewing angle with good visibility, an optical compensation position in which an alignment layer of a liquid crystal polymer, particularly an optically anisotropic layer composed of a tilted alignment layer of a discotic liquid crystal polymer, is supported by a triacetyl cellulose film. A phase difference plate can be preferably used.

  A polarizing plate obtained by bonding a polarizing plate and a brightness enhancement film is usually provided on the back side of a liquid crystal cell. The brightness enhancement film reflects a linearly polarized light with a predetermined polarization axis or a circularly polarized light in a predetermined direction when natural light is incident due to a backlight such as a liquid crystal display device or reflection from the back side, and transmits other light. In addition, 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 enter to obtain transmitted light in a predetermined polarization state, and reflects light without transmitting the light other than the predetermined polarization state. The The light reflected on the surface of the brightness enhancement film is further inverted through a reflective layer or the like 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. Luminance can be improved by increasing the amount of light transmitted through the enhancement film and increasing the amount of light that can be used for liquid crystal display image display or the like by supplying polarized light that is difficult to be absorbed by the polarizer. That is, when light is incident through the polarizer from the back side of the liquid crystal cell without using a brightness enhancement film, light having a polarization direction that does not coincide with the polarization axis of the polarizer is almost polarized. It is absorbed by the polarizer and does not pass through the polarizer. That is, although depending on the characteristics of the polarizer used, approximately 50% of the light is absorbed by the polarizer, and accordingly, the amount of light that can be used for liquid crystal image display or the like is reduced and the image becomes dark. The brightness enhancement film reflects light that has a polarization direction that is absorbed by the polarizer without being incident on the polarizer, and is reflected by the brightness enhancement film, and then inverted through a reflective layer or the like provided behind the brightness enhancement film. The brightness enhancement film transmits only the polarized light in which the polarization direction of the light reflected and inverted between the two is allowed to pass through the polarizer. Since the light is supplied to the polarizer, light such as a backlight can be efficiently used for displaying an image on the liquid crystal display device, and the screen can be brightened.

  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 reflective layer or the like, but the installed diffuser plate uniformly diffuses the light passing therethrough and simultaneously cancels the polarized state and becomes a non-polarized state. That is, the light in the natural light state is directed toward the reflection layer or the like, reflected through the reflection layer or the like, and again passes through the diffusion plate 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, the brightness of the display screen is reduced and uniform. Can provide a bright screen. By providing such a diffuser plate, it is considered that the first incident light has a moderate increase in the number of repetitions of reflection, and in combination with the diffusion function of the diffuser plate, a uniform bright display screen can be provided.

  The brightness enhancement film has a characteristic of transmitting linearly polarized light having a predetermined polarization axis and reflecting other light, such as a multilayer thin film of dielectric material or a multilayer laminate of thin film films having different refractive index anisotropies. Such as an alignment film of a cholesteric liquid crystal polymer or an alignment liquid crystal layer supported on a film substrate, which reflects either left-handed or right-handed circularly polarized light and transmits other light. Appropriate things, such as a thing, can be used.

  Therefore, in the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis as described above, the transmitted light is incident on the polarizing plate with the polarization axis aligned as it is, thereby efficiently transmitting while suppressing absorption loss due to the polarizing plate. Can be made. 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 incident on a polarizer as it is, but from the point of suppressing absorption loss, the circularly polarized light is converted into linearly polarized light through a retardation plate. It is preferably incident on the polarizing plate. Note that circularly polarized light can be converted to linearly polarized light by using a quarter wave plate as the retardation plate.

  A retardation plate that functions as a quarter-wave plate at a wide wavelength in the visible light region or the like exhibits, for example, a retardation plate that functions as a quarter-wave plate for light-colored light having a wavelength of 550 nm and other retardation characteristics. It can be obtained by a method in which a phase difference layer, for example, a phase difference layer that functions as a half-wave plate is superimposed. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may be composed of one or more retardation layers.

  In addition, a cholesteric liquid crystal layer having a reflection structure that reflects circularly polarized light in a wide wavelength range such as a visible light range can be obtained by combining two or more layers with different reflection wavelengths to form an overlapping structure. Based on this, transmitted circularly polarized light in a wide wavelength range can be obtained.

  Further, the polarizing plate may be formed by laminating a polarizing plate and two or more optical layers as in the above-described polarization separation type polarizing plate. Therefore, a reflective elliptical polarizing plate or a semi-transmissive elliptical polarizing plate in which the above-described reflective polarizing plate or semi-transmissive polarizing plate and a retardation plate are combined may be used.

  An optical film in which the optical layer is laminated on a polarizing plate can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. There is an advantage that the manufacturing process of a liquid crystal display device or the like can be improved because of excellent stability and assembly work. For the lamination, an appropriate adhesive means such as an adhesive layer can be used. When adhering the polarizing plate and the other optical layer, their optical axes can be set at an appropriate arrangement angle in accordance with the target phase difference characteristic.

  A method for coating the anchor layer 2 on the optical film 1 using the silane coupling agent is not particularly limited. For example, the silane coupling agent is undiluted, or a solution or dispersion in which water, an organic solvent, and a mixed solvent thereof are dissolved or dispersed is applied onto the optical film 1 and then dried at room temperature or heat-treated to fix the anchor layer. The method of forming 2 is preferable because it is easy to make industrially.

  Although there is no restriction | limiting in particular as a density | concentration of the solution or dispersion liquid of a silane coupling agent, Usually, it is preferable from a viewpoint that the anchor layer 2 can be formed stably 0.1 weight% or more. More preferably, it is 1 to 10% by weight. As the organic solvent, it is desirable that the silane coupling agent can be uniformly dissolved or dispersed and has an appropriate volatility. Specific examples of the organic solvent include alcohols such as methanol, ethanol and propyl alcohol, ketones such as acetone and methyl ethyl ketone, and aromatic hydrocarbons such as benzene, toluene and xylene. These organic solvents can be used alone or in combination.

  As a method of applying the silane coupling agent or a solution or dispersion thereof on the optical film 1, a method usually used for applying a liquid substance to a solid surface, for example, a gravure coating method, a dip coating method, a spray coating, etc. A coating method such as a method, a die coating method or a casting method can be employed. Usually, after applying the coupling agent or a solution or dispersion thereof, the anchor layer 2 is formed by drying at room temperature or heat treatment. As the heat treatment, treatment in a temperature range of 20 ° C. or more and Tg or less of the optical film 1 is usually performed for 1 minute or more and 10 hours or less.

  In forming the anchor layer 2, the optical film 1 can be activated. Various methods can be employed for the activation treatment, for example, saponification treatment, corona treatment, low-pressure UV treatment, plasma treatment, or the like. The activation treatment is effective particularly when the optical film 1 is triacetyl cellulose, norbornene resin, polycarbonate, polyolefin resin, or the like, and the contact angle of each film with water is 80 degrees or less, preferably 75 degrees or less. Then, repelling when applying the anchor agent can be suppressed. Further, the anchor layer can be formed on the optical film with good adhesion.

  The thickness of the anchor layer 2 (dry film thickness) is not particularly limited, but is preferably as thin as possible as long as an improvement effect such as wettability and adhesion is obtained, and is preferably 20 μm or less. When the above range is exceeded, there is a tendency to cause a practical disadvantage in that the thickness is increased. The thickness of the anchor layer is preferably 500 nm or less, more preferably 300 nm or less, and further preferably 200 nm or less. The peeling charging effect is preferably greater in the thickness of the anchor layer, but even if it exceeds 200 nm, it is equivalent to less than that. From this point, it is preferable to set to 5 to 500 nm, further 10 to 300 nm, and further 10 to 200 nm.

  The pressure-sensitive adhesive layer 3 is formed by laminating on the anchor layer 2. The forming method is not particularly limited, and examples thereof include a method of applying an adhesive (solution) to the anchor layer 2 and drying, a method of transferring using a release sheet 4 provided with the adhesive layer 3, and the like. As a coating method, a roll coating method such as reverse coating or gravure coating, a spin coating method, a screen coating method, a fountain coating method, a dipping method, or a spray method can be adopted. The pressure-sensitive adhesive layer 3 (dry film thickness) is not particularly limited in thickness, but is preferably about 10 to 40 μm.

  As the constituent material of the release sheet 4, suitable thin leaves such as paper, polyethylene, polypropylene, synthetic resin films such as polyethylene terephthalate, rubber sheets, paper, cloth, non-woven fabrics, nets, foam sheets, metal foils, and laminates thereof. Such as body. The surface of the release sheet 4 may be subjected to a release treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment as necessary in order to enhance the peelability from the pressure-sensitive adhesive layer 3.

  As a constituent material of the release sheet, paper, polyethylene, polypropylene, polyethylene terephthalate and other synthetic resin films, rubber sheets, paper, cloth, non-woven fabric, nets, foam sheets and metal foils, and appropriate thin leaf bodies such as laminates thereof Etc. In order to improve the peelability from the pressure-sensitive adhesive layer 3, the surface of the release sheet may be subjected to a low-adhesive release treatment such as silicone treatment, long-chain alkyl treatment, and fluorine treatment as necessary.

  In addition, each layer such as an optical film or an adhesive layer of the pressure-sensitive adhesive optical film of the present invention includes, for example, an ultraviolet ray such as a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, or a nickel complex compound. What gave the ultraviolet absorptivity by systems, such as a system processed with an absorber, may be used.

  The 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. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, an adhesive optical film, and an illumination system as necessary, and incorporating a drive circuit. There is no particular limitation except that an adhesive optical film is used. As the liquid crystal cell, an arbitrary type such as an arbitrary type such as a TN type, an STN type, or a π type can be used.

  An appropriate liquid crystal display device such as a liquid crystal display device in which an adhesive optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflector used in an illumination system can be formed. In that case, the optical film according to the present invention can be installed on one side 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 or a suitable part such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. 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. Generally, 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 injection layer made of a triphenylamine derivative and the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a structure having various combinations such as a stacked body of such a light emitting layer and an electron injection layer made of a perylene derivative, or a stacked body of these hole injection layer, light emitting layer, and electron injection layer is known. It has been.

  In organic EL display devices, holes and electrons are injected into the organic light-emitting layer by applying a voltage to the transparent electrode and the metal electrode, and the energy generated by recombination of these holes and electrons excites the phosphor material. Then, light is emitted on the principle that the excited fluorescent material emits light when returning to the ground state. The mechanism of recombination in the middle is the same as that of a general diode, and as can be predicted from this, the current and the emission intensity show strong nonlinearity with rectification with respect to the applied voltage.

  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 a transparent electrode usually formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. It is used as. 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 usually metal electrodes such as Mg—Ag and Al—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 having a thickness of about 10 nm. For this reason, the organic light emitting layer transmits light almost completely like the transparent electrode. As a result, light that is incident from the surface of the transparent substrate at the time of non-light emission, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode is again emitted to the surface side of the transparent substrate. The display surface of the organic EL display device looks like a mirror surface.

  In an organic EL display device comprising an organic electroluminescent light emitting device comprising a transparent electrode on the surface side of an organic light emitting layer that emits light upon application of a voltage and a metal electrode on the back side of the organic light emitting layer, the surface of the transparent electrode While providing a polarizing plate on the side, a retardation plate can be provided between the transparent electrode and the polarizing plate.

  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 action. In particular, the mirror surface of the metal electrode can be completely shielded by configuring the retardation plate with a quarter-wave plate and adjusting the angle formed by the polarization direction of the polarizing plate and the retardation plate to π / 4. .

  That is, only the linearly polarized light component of the external light incident on the organic EL display device is transmitted by the polarizing plate. This linearly polarized light becomes generally elliptically polarized light by the phase difference plate, but becomes circularly polarized light particularly when the phase difference plate is a quarter wavelength plate and the angle formed by the polarization direction of the polarizing plate and the phase difference plate is π / 4. .

  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 becomes linearly polarized light again on the retardation plate. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot permeate | transmit a polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight.

Example 1
(Optical film)
A transparent protective film (thickness 40 μm) of a polarizer using a norbornene resin (manufactured by Nippon Zeon Co., Ltd., ZEONOR) was subjected to corona treatment at a discharge amount of 133 w · min / m ² .

(Formation of anchor layer)
A solution was prepared by adding 66.7 parts of isopropyl alcohol to 100 parts of a silane coupling agent having an amino group (manufactured by Nippon Unicar Co., Ltd., APZ-6601, coupling agent concentration 5%). A diluted solution was prepared. This solution was applied onto the corona-treated surface of the optical film using a wire bar # 5, and then volatile components were evaporated. The thickness of the anchor layer formed by the silane coupling agent after evaporation was 100 nm.

(Formation of adhesive layer)
As a base polymer, a solution (solid content 30) containing an acrylic polymer having a weight average molecular weight of 2 million consisting of a copolymer of butyl acrylate: acrylic acid: 2-hydroxyethyl acrylate = 100: 5: 0.1 (weight ratio) %) Was used. Viscosity adjustment of 4 parts of Coronate L manufactured by Nippon Polyurethane Co., Ltd., an isocyanate-based polyfunctional compound, and 100 parts of polymer solids and 0.5 part of additive (manufactured by Shin-Etsu Silicone, KBM403) in the acrylic polymer solution. A solvent (ethyl acetate) was added to prepare an adhesive solution (solid content 12%). The adhesive solution was applied on a release film (polyethylene terephthalate substrate: Diafoil MRF38, manufactured by Mitsubishi Chemical Polyester Co., Ltd.) so that the thickness after drying was 25 μm, and then dried in a hot air circulation oven. An adhesive layer was formed.

(Preparation of adhesive optical film)
A release film in which an adhesive layer was formed was bonded to the anchor layer formed on the surface of the optical film to produce an adhesive optical film.

Example 2
(Production of optical film)
A saponification treatment was performed on a transparent protective film (thickness: 80 μm) of a polarizer using triacetylcellulose.

(Preparation of adhesive optical film)
In Example 1, except that the above optical film was used as an optical film, an anchor layer was formed in the same manner as in Example 1, and a release film in which the same adhesive layer as in Example 1 was formed was bonded. An adhesive optical film was prepared.

Comparative Example 1
In Example 1, an adhesive optical film was produced in the same manner as in Example 1 except that the anchor layer was not formed.

Comparative Example 2
In Example 2, an adhesive optical film was produced in the same manner as in Example 2 except that the anchor layer was not formed.

  The following evaluation was performed about the optical film obtained by the Example and the comparative example. The results are shown in Table 1.

(Adhesion between adhesive layer and optical film substrate)
The above adhesive optical film is cut to a size of 25 mm × 150 mm, and the adhesive layer surface is bonded to the vapor deposition surface of the vapor deposition film in which indium-tin oxide is vapor-deposited on the surface of the 50 μm thick polyethylene terephthalate film. After that, it was left in an environment of 23 ° C./60% RH for 20 minutes or more. Then, after peeling off the edge part of a polyethylene terephthalate film by hand and confirming that the adhesive has adhered to the polyethylene terephthalate film side, 180 degree direction was used using the Shimadzu Corporation tensile tester AG-1. The stress (N / 25 mm) when peeled at a speed of 300 mm / min was measured (25 ° C.).

(Adhesive remaining)
The pressure-sensitive adhesive optical film is cut to a size of 15 cm × 15 cm, and the pressure-sensitive adhesive layer surface thereof is attached to a liquid crystal panel (Sony, VEGA KLV-17HR2, glass surface), and the environment is 23 ° C./60% RH. Left for 1 hour. Then, rework which peels an adhesive optical film from a liquid crystal panel by hand was performed, and the state of the adhesive remaining on the liquid crystal panel surface was visually evaluated. The case where no pressure-sensitive adhesive remained was defined as “none”, and the case where a pressure-sensitive adhesive remained even a little was defined as “present”.

It is sectional drawing of the adhesion type optical film of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical film 2 Anchor layer 3 Adhesive layer 4 Release sheet

Claims (7)

In an adhesive optical film in which an adhesive layer is laminated on at least one surface of the optical film,
The pressure-sensitive adhesive optical film is characterized in that the pressure-sensitive adhesive layer is laminated via an anchor layer formed of a silane coupling agent.   The pressure-sensitive adhesive optical film according to claim 1, wherein the silane coupling agent is an amino group-containing silane coupling agent.   The pressure-sensitive adhesive optical film according to claim 1 or 2, wherein the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive.   The pressure-sensitive adhesive optical film according to claim 2 or 3, wherein the base polymer of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer contains a functional group that reacts with an amino group.   The pressure-sensitive adhesive optical film according to claim 4, wherein the functional group that reacts with an amino group contained in the base polymer of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is a carboxyl group.   The pressure-sensitive adhesive optical film according to any one of claims 1 to 5, wherein the material on the surface of the optical film on which the anchor layer is laminated is triacetyl cellulose, norbornene resin or polycarbonate. An image display device using at least one adhesive optical film according to claim 1.

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