JP4486675B2 - Method for producing adhesive optical film - Google Patents

Description

  The present invention relates to a method for producing an adhesive optical film in which an adhesive layer is laminated on one surface of an optical film via a resin layer. The pressure-sensitive adhesive optical film obtained by the manufacturing method is used for image display devices such as liquid crystal display devices, organic EL display devices, PDPs, and CRTs. Examples of the optical film include a polarizing film or a film in which a retardation film, an optical compensation film, a brightness enhancement film, an antiglare sheet and the like are laminated.

  In the liquid crystal display, it is indispensable to arrange polarizing elements on both sides of the glass substrate that forms the outermost surface of the liquid crystal panel because of its image forming method. Generally, a polarizing film is attached to the surface of the liquid crystal panel. Yes. In addition to polarizing films, various optical elements have been used on the surface of liquid crystal panels in order to improve the display quality of displays. For example, a retardation film 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.

  When sticking the optical film on the surface of the liquid crystal panel, an adhesive is usually used. In addition, since the optical film can be instantly fixed to the outermost surface of the liquid crystal panel and has a merit that a drying process is not required to fix the optical film, the adhesive is preliminarily applied to one side of the optical film. It is provided as a layer. That is, an adhesive optical film is generally used for attaching an optical film to the surface of a liquid crystal panel.

  Necessary characteristics required for the pressure-sensitive adhesive are as follows: (1) When an optical film is bonded to the outermost surface of the liquid crystal panel, the optical film is also used in the case where the bonding position is wrong or a foreign object is caught in the bonding surface. The film can be peeled off from the surface of the liquid crystal panel and pasted (reworked) again. (2) It has stress relaxation properties to prevent optical unevenness caused by dimensional change of the optical film. (3) Environmental promotion test. As a result, there is no problem caused by the pressure-sensitive adhesive with respect to a durability test by heating and humidification that is usually performed.

  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).

  In addition, the display frame using a liquid crystal panel has recently become narrower and display quality may be significantly deteriorated due to defects occurring at the edge of the liquid crystal panel. Became. There are various defects at the end of the optical film, but the most common is a problem that the adhesive is missing at the end (hereinafter referred to as adhesive lack). This occurs when the end of the optical film hits an object during handling of the optical film and a part of the pressure-sensitive adhesive layer is missing. Many of these problems occur in conventional adhesive optical films.

  The present invention provides a pressure-sensitive adhesive optical film provided with a pressure-sensitive adhesive layer for adhering an optical film to a glass substrate or the like of a liquid crystal panel, and has a pressure-sensitive adhesive residue and a pressure-sensitive adhesive chip. For the purpose. Furthermore, it aims at providing the image display apparatus using the said adhesive type optical film.

  The present inventors have intensively studied to solve the above problems, and found that the above-described object can be achieved by the following adhesive optical film, and have completed the present invention.

That is, the present invention is a method for producing an adhesive optical film in which at least one resin layer is formed on one surface of an optical film, and an adhesive layer is laminated on the resin layer,
The pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive, and a resin layer adjacent to the pressure-sensitive adhesive layer (however, a light diffusion layer having a fine concavo-convex structure with a center line average roughness of 0.2 μm or more on the outer surface is provided. Except) The present invention relates to a method for producing an adhesive optical film, wherein the surface has a pencil hardness of 2B or less.

  The pressure-sensitive adhesive optical film obtained by the production method of the present invention is considered to be due to low adhesiveness between the acrylic pressure-sensitive adhesive layer and the optical film substrate because the pressure-sensitive adhesive remains and the pressure-sensitive adhesive lack occurs. Adhesion is improved by improving the wettability of the surface on which the agent layer is laminated. In order to improve the wettability with respect to the acrylic pressure-sensitive adhesive layer, a soft surface having a pencil hardness of 2B or less is employed. Thereby, even when the adhesive optical film is peeled off from the liquid crystal panel or the like, the adhesive remaining on the liquid crystal panel of the adhesive layer laminated on the optical film can be prevented. Moreover, when the adhesive optical film is handled, it is possible to greatly reduce adhesive chipping in which part of the adhesive drops off at the film edge. The pencil hardness of the surface on which the pressure-sensitive adhesive layer is laminated has a softness of 2B or less, and more preferably a softness of 3B or less. In terms of productivity, the pencil hardness is preferably 5B or more.

  In the pressure-sensitive adhesive optical film, a pressure-sensitive adhesive layer is laminated on the optical film via at least one resin layer, and the pencil hardness of the surface of the resin layer adjacent to the pressure-sensitive adhesive layer is 2B or less. The surface on which the pressure-sensitive adhesive layer is laminated is such that the surface of the resin layer laminated on the optical film has a hardness of 2B or less. In general, when the surface hardness of an optical film is 2B or less, it is difficult to achieve both optical properties and mechanical properties. Therefore, it is preferable to laminate a highly transparent resin layer that satisfies optical characteristics and mechanical characteristics.

  The resin layer adjacent to the pressure-sensitive adhesive layer is preferably formed of a polyurethane resin. The material for forming the resin layer is not particularly limited, but a polyurethane-based resin is preferable. In addition, the example which provided the ethyleneimine adduct of polyacrylic acid ester as an anchor layer between an adhesive layer and an optical film base material is known (Unexamined-Japanese-Patent No. 10-20118). However, since the anchor layer has a surface hardness exceeding 2B, it cannot be said that the adhesion between the pressure-sensitive adhesive layer and the optical film substrate can be sufficiently improved.

  In the method for producing the pressure-sensitive adhesive optical film, it is preferable that the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer contains, as a base polymer, an acrylic polymer containing a monomer having an N element as a monomer unit. The acrylic polymer that is the base polymer of the acrylic pressure-sensitive adhesive is not particularly limited, but a monomer having an N element monomer, preferably a monomer having a functional group containing N element as a monomer unit, This is preferable because of improved adhesion. In particular, it is suitable when the laminated surface is a resin layer, and particularly when it is a polyurethane resin layer.

  In the method for producing the pressure-sensitive adhesive optical film, it is preferable that the acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer contains an isocyanate polyfunctional compound. A polyfunctional compound can be blended in the acrylic adhesive, but among the polyfunctional compounds, the isocyanate polyfunctional compound is used as a protective layer on the outermost surface of the optical film (polarizing film) through the resin layer. It can react with a hydroxyl group present in triacetylcellulose, diacetylcellulose, monoacetylcellulose, etc., and is preferable because the adhesion between the resin layer and the optical film (protective layer of the polarizing film) is improved.

  The pressure-sensitive adhesive optical film obtained by the manufacturing method is used according to the usage mode of various image display devices such as a liquid crystal display device. .

  The acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive optical film of the present invention uses 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.

  Various monomer units such as a monomer unit having a carboxyl group, a monomer unit having a hydroxyl group, and a monomer unit having an N element can be introduced into the acrylic polymer. Among these, a monomer unit having an N element is preferable. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, and itaconic acid. Examples of the monomer having a hydroxyl group include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate and N-methylol (meth) acrylamide, hydroxybutyl (meth) acrylate, and hydroxyhexyl (meth) acrylate. 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, monomers having a functional group such as a monomer containing an epoxy group such as glycidyl (meth) acrylate, vinyl acetate, styrene, etc. can be used for the acrylic polymer 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 ratio of the monomer unit (a) other than the alkyl (meth) acrylate in the acrylic polymer is not particularly limited, but the monomer unit (A) constituting the acrylic polymer (excluding the monomer unit (a)) and The weight ratio (a / A) is preferably about 0.001 to 0.12, more preferably 0.005 to 0.1.

  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 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 polyfunctional compound that can be blended in the acrylic 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. Among these, Al, Zr, and Ti are preferable. Examples of the atom in the organic compound that is covalently or coordinately bonded include an oxygen atom, and the organic compound includes an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, a ketone compound, and the like.

  The blending ratio of the acrylic polymer and the polyfunctional compound is not particularly limited. Usually, the polyfunctional compound (solid content) is about 0.01 to 6 parts by weight with respect to 100 parts by weight of the acrylic polymer (solid content). Preferably it is about 0.1-3 weight part.

  Furthermore, the pressure-sensitive adhesive composition, if necessary, a tackifier, a plasticizer, a glass fiber, glass beads, a metal powder, a filler composed of other inorganic powders, a pigment, a colorant, a filler, Antioxidants, ultraviolet absorbers, silane coupling agents, and the like, and various additives can be appropriately used without departing from the object of the present invention. Moreover, the adhesive layer etc. which contain microparticles | fine-particles and show light diffusibility may be sufficient.

  A resin layer is interposed between the optical film and the pressure-sensitive adhesive layer. The resin layer forming material is not particularly limited, and examples thereof include various resins such as an acrylic resin, a polyester resin, and a polyurethane resin. The form of these resins may be any of solvent-soluble type, water-dispersed type, and water-soluble type. This resin layer can be provided with at least one layer. When a plurality of resin layers are provided, each resin layer forming material may be the same material or the same material. In addition, as above-mentioned, the pencil hardness of the resin layer surface adjacent to an adhesive layer is 3 B or less.

  A polyurethane-based resin can be preferably used as the resin layer forming material. A polyurethane resin or a urethane prepolymer is used as the polyurethane resin. The polyurethane resin is a polyurethane or a modified product obtained by reacting a chain extender and a chain terminator as necessary, with a polyol component and a polyisocyanate component as main components. The urethane prepolymer generally comprises a polyol component and a polyisocyanate component as main components and has an isocyanate group or a blocked isocyanate group at the terminal.

  Examples of the polyol component include polyether polyols such as polyethylene glycol, polypropylene glycol and polyoxytetramethylene ether glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like; ethylene glycol, diethylene glycol, triethylene glycol, 1, 2 -Propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, Saturated or unsaturated various known low molecular glycols such as octanediol, 1,4-butynediol, dipropylene glycol, bisphenol A, hydrogenated bisphenol A; Molecular glycols and dibasic acids such as adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid Polyester polyols obtained by dehydration condensation of acids or acid anhydrides corresponding thereto; polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and β-methyl-δ-valerolactone; Various known polymer polyols generally used for the production of polyurethane such as polycarbonate polyols and polybutadiene glycols are exemplified. In addition, a part of the low molecular glycol component is various polyols such as glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, pentaerythritol, sorbitol and the like. You can also.

  As the polyisocyanate compound, various known aromatic, aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4- Trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate Isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate and the carboxyl group of dimer acid were converted to isocyanate groups A typical example is dimer isocyanate.

  Examples of isocyanate group blocking agents include bisulfites and sulfonic acid group-containing phenols, alcohols, lactam oximes, and active methylene compounds.

  Examples of the chain extender include various known low molecular glycols listed in the description of the polyester diol; ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4. Examples include amines such as' -diamine and water. In addition, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, etc. Representative examples include diamines having a hydroxyl group; dimer diamine obtained by converting a carboxyl group of dimer acid into an amino group, and the like.

  Examples of the chain terminator include monoamines such as monobutylamine and dibutylamine; monoamines having a hydroxyl group such as monoethanolamine and diethanolamine; monoamines having a primary alcoholic hydroxyl group such as ethanol and n-butanol. Examples include alcohols.

The polyurethane resin can be used as a solution appropriately dissolved in an organic solvent. As the polyurethane resin, a resin that is dissolved in an organic solvent inert to an isocyanate group or the like and dispersed or dissolved in water can be used. The water-based dispersibility or solubility is, for example, by introducing a hydrophilic group such as a carboxylate, a sulfonate group or a sulfate half ester base into a polyurethane or urethane prepolymer, or an ethylene oxide adduct. It is performed by using a polyol component having a hydrophilic part such as.

  For introducing a hydrophilic group such as a carboxylate into a polyurethane or urethane prepolymer, for example, a carboxyl group-containing diol is used as a diol component. As the carboxyl group-containing diol, α, α′-dimethylolalkanoic acid (glyceric acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, etc.), dioxymaleic acid, dioxyfumaric acid, tartaric acid 2,6-dioxybenzoic acid, 4,4-bis (hydroxyphenyl) valeric acid, 4,4-bis (hydroxyphenyl) butyric acid, etc., and ε-caprolactone and γ-butyrolactone using these carboxyl group-containing diols as initiators And those obtained by ring-opening polymerization of lactones such as γ-valerolactone.

  In addition to the above, examples of the hydrophilic group-introducing component include amino group or hydroxyl group-containing carboxylic acid and amino group or hydroxyl group-containing sulfonic acid. Examples of the amino group-containing carboxylic acid include β-aminopropionic acid, γ-aminobutyric acid, p-aminobenzoic acid, and the like. Examples of the hydroxyl group-containing carboxylic acid include 3-hydroxypropionic acid, γ-hydroxybutyric acid, Examples thereof include p- (2-hydroxyethyl) benzoic acid and malic acid. Examples of the compound having an amino group or a hydroxyl group and a sulfonic acid group include aminomethanesulfonic acid, 2-aminoethanesulfonic acid, and 2-amino-5. -Methylbenzene-2-sulfonic acid, sodium β-hydroxyethanesulfonate, propane sultone and butane sultone addition products of aliphatic diprimary amine compounds. Furthermore, examples of the compound containing an amino group or a hydroxyl group and a sulfuric acid half ester group include aminoethanol sulfate, aminobutanol sulfate, hydroxyethanol sulfate, α-hydroxybutanol sulfate and the like.

  In addition, for neutralization of the carboxyl group, alkali metals such as potassium hydroxide and sodium hydroxide, ammonia or trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-alkyldiethanolamine, N, N ′ -Tertiary amines such as dialkyl monoethanolamine are used.

  As shown in FIG. 1, the reference adhesive optical film has an optical film 1 and an adhesive layer 3 directly laminated on the optical film 1. In the pressure-sensitive adhesive optical film obtained by the production method of the present invention, a pressure-sensitive adhesive layer 3 is laminated on an optical film 1 with a resin layer 2 interposed therebetween as shown in FIG. The surface of the resin layer 2 in FIG. 2 has a pencil hardness of 3B or less. A release sheet 4 can be provided on the pressure-sensitive adhesive layer 3. FIG. 2 illustrates the case where one resin layer 2 is provided. A plurality of resin layers 2 can be provided. In that case, the pencil hardness of the surface of the resin layer 2 adjacent to the pressure-sensitive adhesive layer 3 is 3B or less.

  As the optical film 1, one used for forming a liquid crystal display device or the like is used, and the type thereof is not particularly limited. For example, the optical film includes a polarizing film. A polarizing film (polarizing plate) generally has a transparent protective film on one or both sides of a polarizer.

  The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol film, partially formalized polyvinyl alcohol film, and ethylene / vinyl acetate copolymer partially saponified film, and two colors such as iodine and dichroic dye. Examples thereof include polyene-based oriented films such as those obtained by adsorbing volatile 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 produced, for example, by dyeing 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 and 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, or may be performed while dyeing, or may be performed with dyeing after iodine. The film can be stretched 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 shielding 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. 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. Among these, a cellulose polymer is preferable. Although the thickness in particular of a transparent protective film is not restrict | limited, Generally it is 500 micrometers or less, and 1-300 micrometers is preferable. In particular, the thickness is preferably 5 to 200 μm.

  The surface of the transparent protective film to which the polarizer is not adhered (the surface on which the coating layer is not provided) has been subjected to a hard coat layer, antireflection treatment, antisticking, or treatment for diffusion or antiglare. Also good.

  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 anti-sticking treatment is performed for the purpose of preventing adhesion with an adjacent layer.

  The anti-glare treatment is applied for the purpose of preventing the outside 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 a sandblasting method or an embossing method. 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 blending method of transparent particles. The fine particles to be included in the formation of the surface fine concavo-convex structure are, for example, conductive materials made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide or the like having an average particle size of 0.5 to 50 μm. In some cases, transparent fine particles such as inorganic fine particles, organic fine particles composed of a crosslinked or uncrosslinked polymer, and the like 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 antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

  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.

  For the adhesion treatment between the polarizer and the transparent protective film, an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyester, or the like is used.

  The optical film of the present invention can be used by laminating another optical layer in practical use on the polarizing plate. The optical layer is not particularly limited. For example, for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), and a viewing angle compensation film. One or more optical layers that may be used can be used. 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 viewing angle compensation film is further laminated on a plate, or a polarizing plate in which a brightness 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. Moreover, the transparent protective film contains fine particles so as to have 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. The transparent 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 transparent the metal by an appropriate method such as a vapor deposition method such as a vacuum vapor deposition method, an ion plating method, a sputtering method, or a plating method. It can be performed by a method of directly attaching to the surface of the protective layer.

  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 or the like that displays an image using a built-in light 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 is useful for forming a liquid crystal display device of a type that can save energy of using a light source such as a backlight in a bright atmosphere and can be used with a built-in light source 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, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, or binary, ternary copolymers, graft copolymers, blends Things are given. These polymer materials become oriented products (stretched films) by stretching or the like.

  Examples of the liquid crystalline 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. It is done. Specific examples of the main chain type liquid crystalline polymer include, for example, a nematic alignment polyester liquid crystalline polymer, a discotic polymer, and a cholesteric polymer having a structure in which a mesogen group is bonded to a spacer portion that imparts flexibility. . Specific examples of the side chain type liquid crystalline polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a nematic alignment imparting paraffin through a spacer portion composed of a conjugated atomic group as a side chain. Examples thereof include those having a mesogen moiety composed of a substituted cyclic compound unit. These liquid crystalline polymers are prepared by, for example, applying a solution of a liquid crystalline polymer on an alignment surface such as those obtained by rubbing the surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or by obliquely depositing 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 those for the purpose of compensating for various wavelength plates or birefringence of the liquid crystal layer, viewing angle, and the like. What laminated | stacked the phase difference plate and controlled optical characteristics, such as phase difference, etc. may be used.

  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 viewing angle compensation film is a film for widening the viewing angle so that an 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. As such a viewing angle compensation phase difference plate, for example, a retardation film, an alignment film such as a liquid crystal polymer, or an alignment layer such as a liquid crystal polymer supported on a transparent substrate is used. A normal retardation plate uses a birefringent polymer film uniaxially stretched in the plane direction, whereas a retardation plate used as a viewing angle compensation film stretches biaxially 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 be mentioned. 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.

  Also, from the viewpoint of achieving a wide viewing angle with good visibility, an optically compensated phase difference in which a liquid crystal polymer alignment layer, in particular an optically anisotropic layer composed of a discotic liquid crystal polymer gradient alignment layer, is supported by a triacetylcellulose film. A 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 the amount of light that can be used for liquid crystal image display or the like is reduced accordingly, resulting in a dark image. The brightness enhancement film allows light having a polarization direction that is absorbed by the polarizer to be reflected once by the brightness enhancement film without being incident on the polarizer, and further inverted through a reflective layer provided on the rear side thereof. Repeatedly re-enter the brightness enhancement film, and the brightness enhancement film transmits only polarized light whose polarization direction is such that the polarization direction of light reflected and inverted between the two can pass through the polarizer. Therefore, 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.

  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. As shown (made by 3M, D-BEF, etc.), an orientation film of the cholesteric liquid crystal polymer and the orientation liquid crystal layer supported on the film substrate (made by Nitto Denko, PCF350, Merck, Transmax, etc.), Any suitable one can be used, such as one that reflects either left-handed or right-handed circularly polarized light and transmits other light.

  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 as it is with the polarization axis aligned, 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 emits circularly polarized light such as a cholesteric liquid crystal layer, it can be incident on a polarizer as it is, but from the viewpoint of suppressing absorption loss, the circularly polarized light is linearly polarized through a retardation plate. It is preferable to make it enter into a 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 in a wide wavelength range such as a visible light region exhibits, for example, a retardation layer that functions as a quarter-wave plate for light-color light having a wavelength of 550 nm and other retardation characteristics. It can be obtained by a method of superposing a retardation layer, for example, a retardation layer functioning as a half-wave plate. 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, the cholesteric liquid crystal layer can also be obtained by reflecting circularly polarized light in a wide wavelength range such as a visible light region by combining two or more layers having different reflection wavelengths and having 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 three or more optical layers like 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-mentioned reflective polarizing plate or transflective 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.

  The method for forming the resin layer 2 on the optical film 1 is not particularly limited, and examples thereof include a method of applying a solution or dispersion of the resin layer forming material to the optical film 1 and drying. The thickness of the resin layer 2 (dry film thickness) is not particularly limited, but is preferably about 0.01 to 2 μm.

  The pressure-sensitive adhesive layer 3 is formed by laminating on the resin layer 2 formed on the optical film 1. The forming method is not particularly limited, and examples thereof include a method of applying and drying a pressure-sensitive adhesive composition (solution), and a method of transferring with a release sheet 4 provided with a pressure-sensitive adhesive layer 3. The pressure-sensitive adhesive layer 3 (dry film thickness) is not particularly limited in thickness, but is preferably about 10 to 40 μm.

  In addition, as a constituent material of the release sheet 4, paper, polyethylene, polypropylene, synthetic resin films such as polyethylene terephthalate, rubber sheets, paper, cloth, nonwoven fabric, nets, foam sheets, metal foils, laminates thereof, and the like are appropriately used. Thin leaf bodies and the like. The surface of the release sheet 4 may be subjected to a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment release treatment as necessary in order to enhance the peelability from the pressure-sensitive adhesive layer 3.

  In addition, each layer such as the optical film and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive optical film of the present invention has an ultraviolet absorption such as a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, or a nickel complex compound. It may be one having an ultraviolet absorbing ability by a method such as a method of treating with an agent.

  The pressure-sensitive adhesive optical film of the present invention can be preferably used for forming various devices such as a liquid crystal display device. 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 a polarizing plate or an optical film is used. As the liquid crystal cell, any 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 polarizing plate or optical film by this invention can be installed in the one side or both sides of a liquid crystal cell. When providing a polarizing plate or an optical film 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. 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 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 laminate of such a light emitting layer and an electron injection layer composed of a perylene derivative or the like, or a laminate 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.

  A surface of a transparent electrode in an organic EL display device including an organic electroluminescent light emitting device including a transparent electrode on a surface side of an organic light emitting layer that emits light by applying a voltage and a metal electrode on a back surface side of the organic light emitting layer. 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 each example, parts are parts by weight. The measurement of the pencil hardness on the surface of the resin layer is based on JISK-5400.

Example 1
(Preparation of adhesive)
While stirring 96 parts of butyl acrylate, 3.9 parts of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate, 0.3 part of azobisisobutyronitrile and 250 parts of ethyl acetate, the reaction is performed at around 60 ° C. for 6 hours. An acrylic polymer solution having a weight average molecular weight of 1.1 million was obtained. 0.5 parts of Coronate L manufactured by Nippon Polyurethane Co., Ltd., which is an isocyanate-based polyfunctional compound, was added to the acrylic polymer solution with respect to 100 parts of polymer solids to prepare an adhesive solution.

(Preparation of adhesive optical film)
A polyvinyl alcohol film having a thickness of 80 μm was stretched 5 times in an aqueous iodine solution and then dried, and a triacetyl cellulose film was adhered to both sides via an adhesive to obtain a polarizing film. The surface of this polarizing film was coated with Adekabon titer HUX290H manufactured by Asahi Denka Kogyo Co., Ltd., which is a water-dispersible polyurethane resin, and dried to a thickness of 1.2 μm to obtain a polarizing film with a resin layer. . The pencil hardness on the surface of the resin layer was 3B. The pressure-sensitive adhesive solution prepared as described above was applied onto a release paper having a thickness of 35 μm so that the thickness after drying was 18 μm, and this was laminated on the resin layer surface of the polarizing film with a resin layer prepared as described above. A type polarizing film was obtained.

Example 2
(Preparation of adhesive)
While stirring 90 parts of butyl acrylate, 9.9 parts of acrylamide, 0.1 part of 2-hydroxyethyl acrylate, 0.3 part of azobisisobutyronitrile and 250 parts of ethyl acetate, the reaction was performed at around 60 ° C. for 6 hours, An acrylic polymer solution having a weight average molecular weight of 1.4 million was obtained. 0.2 parts of Coronate L manufactured by Nippon Polyurethane Co., Ltd., which is an isocyanate-based polyfunctional compound, was added to the acrylic polymer solution with respect to 100 parts of polymer solids to prepare an adhesive solution.

(Preparation of adhesive optical film)
In Example 1, as the water-dispersible polyurethane resin, Adekabon titer HUX680 manufactured by Asahi Denka Kogyo Co., Ltd. was used, and it was applied and dried so that the thickness after drying was 0.9 μm. Similarly, a polarizing film with a resin layer was produced. The pencil hardness on the surface of the resin layer was 3B. Further, an adhesive polarizing film was produced in the same manner as in Example 1 except that the above adhesive solution was used.

Comparative Example 1
(Preparation of adhesive)
While stirring 88 parts of butyl acrylate, 12 parts of acrylamide, 0.3 part of azobisisobutyronitrile and 250 parts of ethyl acetate, the reaction is carried out at around 60 ° C. for 6 hours to obtain an acrylic polymer solution having a weight average molecular weight of 1.35 million. It was. An adhesive solution was prepared by adding 0.5 part of Coronate L manufactured by Nippon Polyurethane Co., Ltd., which is an isocyanate polyfunctional compound, to 100 parts of the polymer solid content to the acrylic polymer solution.

(Preparation of adhesive optical film)
In Example 1, the pressure-sensitive adhesive solution prepared as described above was applied on a release paper having a thickness of 35 μm so as to have a thickness after drying of 18 μm without forming a resin layer, and this was applied to the polarizing film. Lamination was performed to obtain an adhesive polarizing film. The pencil hardness on the surface of the polarizing film was HB.

Comparative Example 2
(Preparation of adhesive)
While stirring 94 parts of butyl acrylate, 6 parts of acrylic acid, 00.3 parts of azobisisobutyronitrile and 200 parts of ethyl acetate, the reaction was carried out at around 60 ° C. for 6 hours to obtain an acrylic polymer solution having a weight average molecular weight of 1.35 million. Obtained. A pressure-sensitive adhesive solution was prepared by adding 1 part of Coronate L manufactured by Nippon Polyurethane Co., Ltd., which is an isocyanate-based polyfunctional compound, to 100 parts of the polymer solid content to the acrylic polymer solution.

(Preparation of adhesive optical film)
In Example 1, instead of the water-dispersible polyurethane resin, it was carried out except that Polyment NK380 manufactured by Nippon Shokubai Chemical Co., Ltd., which is a polyethyleneimine resin, was applied and dried to a thickness of 0.1 μm. In the same manner as in Example 1, a polarizing film with a resin layer was produced. The pencil hardness on the surface of the resin layer was H. Further, an adhesive polarizing film was produced in the same manner as in Example 1 except that the above adhesive solution was used.

Comparative Example 3
A polarizing film with an anchor layer in the same manner as in Example 1 except that Adekabon titer HUX380 manufactured by Asahi Denka Kogyo Co., Ltd. was used as the water-dispersible polyurethane resin in Example 1 (production of an adhesive optical film). Was made. The pencil hardness on the surface of the resin layer was B. Further, an adhesive polarizing film was produced in the same manner as in Example 1 except that the above adhesive solution was used.

Comparative Example 4
A polarizing film with an anchor layer in the same manner as in Example 1 except that Adekabon titer HUX232 manufactured by Asahi Denka Kogyo Co., Ltd. was used as the water-dispersible polyurethane resin in Example 1 (production of an adhesive optical film). Was made. The pencil hardness on the surface of the resin layer was B. Further, an adhesive polarizing film was produced in the same manner as in Example 1 except that the above adhesive solution was used.

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

[Evaluation]
(Adhesive remaining)
Fifty sheets of the pressure-sensitive adhesive polarizing film prepared as described above were cut into a size of 50 mm × 1500 mm, and bonded to Corning non-alkali glass plate # 1737 and left for 15 minutes in an atmosphere of 50 ° C. × 5 MPa. Next, the adhesive polarizing film was peeled off from the glass at a rate of 300 mm / min in the 180 ° direction. Thereafter, the number of samples (adhesion number) in which the adhesive was adhered on the glass was visually confirmed.

(Adhesive missing)
The pressure-sensitive adhesive polarizing film produced as described above was cut into a size of 25 mm × 150 mm, and this was laminated to form a bundle of polarizing plates. Nitto Denko Co., Ltd. No. 29 adhesive tapes were bonded together at a pressure of 49 N / 25 mm, and then the adhesive tape was peeled off at a peeling speed of 10 m / min in the 90 ° direction. This peeling operation was repeated 10 times. Then, the edge part of each adhesive type polarizing film was confirmed visually, and the number of adhesive type polarizing films (number of chipped pieces) in which the adhesive chip | tip with a width of 1 mm or more and a depth of 0.3 mm or more had arisen was confirmed.

(Adhesion between adhesive layer and polarizing film substrate)
The pressure-sensitive adhesive polarizing film produced as described above was cut into a size of 25 mm × 150 mm, and the pressure-sensitive adhesive layer surface thereof and the vapor-deposited surface of a vapor-deposited film in which indium-tin oxide was vapor-deposited on the surface of a 50 μm-thick polyethylene terephthalate film After being bonded so as to be in contact with each other, 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.). The pressure-sensitive adhesive layer of the pressure-sensitive adhesive optical film and the vapor-deposited surface of the vapor-deposited film have a strong adhesive force. If they are peeled after being bonded together, they are peeled off by the resin layer. Is preferably 16 N / 25 mm or more.

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

Explanation of symbols

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

Claims (5)

A method for producing an adhesive optical film, comprising forming at least one resin layer on one surface of an optical film and laminating an adhesive layer on the resin layer,
The pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive, and a resin layer adjacent to the pressure-sensitive adhesive layer (however, a light diffusion layer having a fine concavo-convex structure with a center line average roughness of 0.2 μm or more on the outer surface is provided. Except) A method for producing a pressure-sensitive adhesive optical film, wherein the surface has a pencil hardness of 2B or less.   The method for producing a pressure-sensitive adhesive optical film according to claim 1, wherein the resin layer adjacent to the pressure-sensitive adhesive layer is formed of a polyurethane-based resin.   The method for producing an adhesive optical film according to claim 1 or 2, wherein the resin layer adjacent to the adhesive layer has a thickness of 0.01 to 2 µm.   The method for producing a pressure-sensitive adhesive optical film according to any one of claims 1 to 3, wherein the acrylic pressure-sensitive adhesive contains an acrylic polymer containing a monomer having an N element as a monomer unit as a base polymer. The method for producing a pressure-sensitive adhesive optical film according to claim 1, wherein the acrylic pressure-sensitive adhesive contains an isocyanate-based polyfunctional compound.

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