JP2004151690A - Optical compensation layer forming material, optical compensation layer, polarizing plate with optical compensation layer, optical film and picture display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate with optical compensation layer in which an optical compensation layer which is fixed by polymerization after being oriented with polymerizable liquid crystal material and a polarizing plate are stacked with adhesive agent layer and cracks are hardly generated in the optical compensation layer. <P>SOLUTION: In the polarizing plate with optical compensation layer in which the optical compensation layer which is fixed by polymerization after being oriented with optical compensation layer forming material including polymerizable liquid crystal material and a polarizing plate are stacked with adhesive agent layer, this polarizing plate with optical compensation layer is characterized by that the optical compensation layer contains polymerizable material having soft segments. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to an optical compensation layer required for improving viewing angle characteristics of a liquid crystal display device and the like, and a polarizing plate with an optical compensation layer. The present invention also relates to an optical film using at least one of the optical compensation layer and the polarizing plate with an optical compensation layer. 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 optical compensation layer, the polarizing plate with the optical compensation layer or the optical film.

  Image display devices such as liquid crystal display devices are widely used as display devices for various information processing devices. However, a twisted nematic liquid crystal display device driven by a thin film transistor that is currently most widely used has a low contrast when viewed from an oblique direction. As a result, there is a viewing angle characteristic that the display characteristic is deteriorated due to the phenomenon that the brightness is reversed in the gradation display. In order to improve this property, there has been reported a polymerized film in which an alignment film is formed on a support, and a discotic nematic phase is tilt-aligned on the alignment film (see Patent Documents 1 and 2).

  As a method for improving viewing angle characteristics, a vertical alignment type liquid crystal (VA mode) display device has been proposed. It is known that a wide viewing angle characteristic is exhibited by applying an optical compensator (retardation plate) for optically compensating the viewing angle of vertically aligned liquid crystal.

Examples of the optical compensation plate include a retardation plate obtained by stretching a polymer film, an alignment film of a liquid crystal polymer, and a layer in which a polymerizable liquid crystal material is aligned and then fixed by polymerization (hereinafter, also referred to as a liquid crystal optical compensation layer). Is raised. Among the optical compensation plates, the optical compensation layer has advantages such as easy alignment of the liquid crystal material, reduction in thickness, and easy optical design. On the other hand, since the optical compensation layer is thin and brittle, it is necessary to support it with a transparent substrate, a polarizing plate, or the like, and is usually provided as a polarizing plate with an optical compensation layer in which an optical compensation layer is attached to a polarizing plate. . However, a polarizing plate with an optical compensation layer may be bent at the time of handling when attaching it to a liquid crystal panel or the like, or a local pressure may be applied at the time of peeling or attaching the separator. Has a problem that cracks easily occur and display on an image display device becomes non-uniform.
Patent No. 2692035 Patent No. 2802719

  The present invention is an optical compensation layer in which a polymerizable liquid crystal material is aligned and then fixed by polymerization, and used as a polarizing plate with an optical compensation layer obtained by laminating this and a polarizing plate via an adhesive layer. In this case, an object of the present invention is to provide an optical compensation layer in which cracks are less likely to occur in the optical compensation layer, and to provide a polarizing plate with the optical compensation layer. Another object of the present invention is to provide an optical film using the optical compensation layer, the polarizing plate with the optical compensation layer, the optical compensation layer, the polarizing plate with the optical compensation layer, and an image display device using the optical film. I do.

  Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the above problem can be solved by an optical compensation layer-attached polarizing plate having the following optical compensation layer laminated thereon, and have completed the present invention. Was.

  That is, the present invention relates to an optical compensation layer forming material containing a polymerizable liquid crystal material and a polymerizable material having a soft segment. In such an optical compensation layer forming material, the polymerizable material having a soft segment is preferably polyethylene glycol diacrylate.

  The present invention also relates to an optical compensation layer, wherein the optical compensation layer forming material is fixed by polymerization after orientation.

  Further, the present invention provides a polarizing plate with an optical compensation layer in which an optical compensation layer formed by polymerizing and fixing an optical compensation layer-forming material containing a polymerizable liquid crystal material is laminated via an adhesive layer. A polarizing plate with an optical compensation layer, wherein the optical compensation layer forming material contains a polymerizable material having a soft segment.

  Further, the present invention provides a polarizing plate with an optical compensation layer in which an optical compensation layer formed by polymerizing and fixing an optical compensation layer-forming material containing a polymerizable liquid crystal material is laminated via an adhesive layer. Wherein the polarizing plate with an optical compensation layer is bent so that the radius of curvature is 10 mm with the optical compensation layer being on the outside, and the optical compensation layer is not cracked when held for 30 seconds. A polarizing plate. In such a polarizing plate with an optical compensation layer, the optical compensation layer forming material preferably contains a polymerizable material having a soft segment.

  In the polarizing plate with an optical compensation layer, polyethylene glycol diacrylate is suitable as the polymerizable material having a soft segment.

  The present invention also relates to an optical film, wherein at least one of the optical compensation layer and the polarizing plate with an optical compensation layer is used.

  Furthermore, the present invention relates to an image display device to which the optical compensation layer, the polarizing plate with the optical compensation layer or the optical film is applied.

  The polarizing plate with an optical compensation layer of the present invention, as a material for forming the optical compensation layer, in addition to the polymerizable liquid crystal material, imparts flexibility to the optical compensation layer by using a polymerizable material having a soft segment, and the polarizing plate Cracks occurring in the optical compensation layer of the laminated polarizing plate with an optical compensation layer are prevented. Such a polarizing plate with an optical compensation layer of the present invention does not crack in the optical compensation layer when the optical compensation layer is bent so that the radius of curvature is 10 mm with the optical compensation layer facing outward. As the polymerizable material having a soft segment, a material having a polymerizable functional group and copolymerizing with a polymerizable liquid crystal material is preferably used.

  In the polarizing plate with an optical compensation layer of the present invention, the optical compensation layer and the polarizing plate are laminated via an adhesive layer. The optical compensation layer is obtained by aligning an optical compensation layer forming material containing a polymerizable liquid crystal material and then fixing the material by polymerization.

  As the polymerizable liquid crystal material, it has various skeletons exhibiting nematic, cholesteric or smectic liquid crystal alignment, and has an acryloyl group, a methacryloyl group, an unsaturated double bond such as a vinyl group or an epoxy group at a terminal. A liquid crystalline compound having at least one polymerizable functional group is used.

  A mesogen group comprising a cyclic unit such as an aromatic unit is bonded to the polymerizable functional group. Examples of the cyclic unit to be a mesogen group include biphenyl, phenylbenzoate, phenylcyclohexane, azoxybenzene, azomethine, azobenzene, phenylpyrimidine, diphenylacetylene, diphenylbenzoate, bicyclohexane, and the like. And cyclohexylbenzenes, terphenyls and the like. In addition, the terminal of these cyclic units may have a substituent such as a cyano group, an alkyl group, an alkoxy group, and a halogen group.

  In addition, the mesogen group may be bonded via a spacer portion that imparts flexibility. Examples of the spacer portion include a polymethylene chain and a polyoxymethylene chain. The number of repeating structural units forming the spacer portion is appropriately determined depending on the chemical structure of the mesogenic portion, but the number of repeating units in the polymethylene chain is 0 to 20, preferably 2 to 12, and the number of repeating units in the polyoxymethylene chain is 0 to 0. 10, preferably 1-3.

  The nematic polymerizable liquid crystal material can be made into a cholesteric liquid crystal material by incorporating a low molecular weight chiral agent or by introducing a chiral component into the molecule. In order to improve the durability of the optical compensation layer, it is preferable to use a polymerizable liquid crystal material having two or more polymerizable functional groups and to crosslink the polymerizable material together with the polymerization.

  A polymerizable material having a soft segment is blended in the optical compensation layer forming material. Examples of the polymerizable functional group of the polymerizable material include those similar to the polymerizable liquid crystal material. At least one polymerizable functional group is introduced into the soft segment. Those having two or more polymerizable functional groups are preferable because they can be crosslinked with polymerization. Examples of the material for the soft segment include those having high flexibility such as polyethylene glycol, polypropylene glycol, polybutylene glycol, and polyisobutylene glycol.

  The degree of polymerization of polyethylene glycol is preferably 3 to 100, preferably 5 to 50, and more preferably 6 to 20, from the viewpoint of imparting flexibility. If the degree of polymerization is too small, the flexibility becomes insufficient, and if it is too large, the orientation of the liquid crystal may be adversely affected. It is preferable that polypropylene glycol and the like have the same degree of polymerization.

  Examples of the polymerizable material having a soft segment include polyethylene glycol diacrylate, polypropylene glycol diacrylate, and the like. The addition amount of the polymerizable material having a soft segment is 0.05 to 3 parts, preferably 0.1 to 2.5 parts, more preferably 0.3 to 2 parts with respect to 100 parts by weight of the polymerizable liquid crystal material. Good. If the amount is less than 0.05 part, the flexibility is insufficient, and if it exceeds 3 parts, the orientation may be poor.

  The optical compensation layer forming material containing a polymerizable liquid crystal material usually contains a polymerization initiator. The polymerization initiator is appropriately selected according to the polymerization method of the polymerizable liquid crystal material or the like. As a method for polymerizing a polymerizable liquid crystal material or the like, for example, ultraviolet polymerization can be mentioned. In this case, a photopolymerization initiator is used. Examples of the photopolymerization initiator include Irgacure 907, 184, 651, and 369 manufactured by Ciba Specialty Chemicals. The amount of the photopolymerization initiator added is such that the orientation is not disturbed in consideration of the type of the polymerizable liquid crystal material and the like. Usually, it is preferably about 0.5 to 30 parts by weight based on 100 parts by weight of the polymerizable liquid crystal material. Particularly, 3 parts by weight or more is preferable. Various additives may be added to the optical compensation layer forming material containing the polymerizable liquid crystal material.

  The optical compensation layer is formed by aligning an optical compensation layer forming material containing a polymerizable liquid crystal material and then fixing the material by polymerization. The orientation can be performed by applying an optical compensation layer forming material to an oriented substrate.

  As the alignment substrate, various types of conventionally known substrates can be used. For example, the alignment substrate was formed by forming a thin alignment film made of polyimide or polyvinyl alcohol on a transparent substrate and rubbing it. And a stretched film obtained by stretching a transparent substrate, or a polymer or polyimide having a cinnamate skeleton or an azobenzene skeleton, which is irradiated with polarized ultraviolet rays.

  The transparent substrate used for the alignment substrate is not particularly limited as long as it does not change at the temperature at which the polymerizable liquid crystal material is aligned. For example, various plastic films, glass plates, metals, etc. of a single layer or a laminate are used. it can. The plastic film is not particularly limited as long as it does not change at the temperature at which it is oriented, and examples thereof include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, polycarbonate polymers, and polymethyl. A film made of a transparent polymer such as an acrylic polymer such as methacrylate may be used. Styrene polymers such as polystyrene and acrylonitrile / styrene copolymer; polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure; olefin polymers such as ethylene / propylene copolymer; vinyl chloride polymers; nylon and aromatic polyamides And a film made of a transparent polymer such as an amide-based polymer. Furthermore, imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers Films made of transparent polymers such as polymers, epoxy polymers and blends of the above polymers are also included.

  The method of applying the optical compensation layer forming material to the oriented substrate may be a solution coating method using a solution of the optical compensation layer forming material in a solvent or a method of melting and melting the optical compensation layer forming material. Of these, the solution coating method is preferred.

  The solvent used for preparing the solution varies depending on the type of the optical compensation layer forming material including the polymerizable liquid crystal material and the polymerizable material having a soft segment, and is appropriately determined. For example, usually, halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, phenols such as phenol and parachlorophenol, benzene, toluene, xylene, methoxybenzene, and 1,2-dichlorobenzene Aromatic hydrocarbons such as methoxybenzene, etc., acetone, ethyl acetate, tert-butyl alcohol, glycerin, ethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, ethyl cellosolve, butyl cellosolve, 2-pyrrolidone , N-methyl-2-pyrrolidone, pyridine, triethylamine, tetrahydrofuran, dimethylformamide, dimethylacetate Amides, dimethyl sulfoxide, acetonitrile, butyronitrile, carbon disulfide, cyclohexanone or the like can be used. The concentration of the solution depends on the solubility of the optical compensation layer forming material such as a polymerizable liquid crystal material and a polymerizable material having a soft segment and the like, and can be determined as appropriate depending on the final thickness of the intended optical compensation layer. Usually, it is in the range of 3 to 50% by weight, preferably 7 to 30% by weight.

  As a method of applying the solution adjusted to a desired concentration using the above-described solvent, for example, a roll coating method, a gravure coating method, a spin coating method, a bar coating method, or the like can be employed. After coating, the solvent is removed. The conditions for removing the solvent are not particularly limited, as long as the solvent can be substantially removed and the alignment layer does not flow or even falls off. Usually, the solvent is removed by using drying at room temperature, drying in a drying furnace, heating on a hot plate, or the like.

  The alignment of the polymerizable liquid crystal material is performed by heat treatment at a temperature at which the material exhibits a liquid crystal state. The heat treatment temperature is appropriately adjusted depending on the polymerizable liquid crystal material. The heat treatment can be performed by the same method as the above-described drying method. The heat treatment time varies depending on the heat treatment temperature and the polymerizable liquid crystal material, and cannot be specified unconditionally. However, it is usually selected in the range of 10 seconds to 2 hours, preferably 20 seconds to 30 minutes.

  After aligning the polymerizable liquid crystal material, polymerization is performed to form an optical compensation layer. As the polymerization method, various means can be adopted according to the type of the polymerizable liquid crystal material and the like, and for example, a photopolymerization method by light irradiation can be adopted. The light irradiation is performed by, for example, ultraviolet irradiation. The ultraviolet irradiation condition is preferably in an inert gas atmosphere in order to sufficiently promote the reaction. A high-pressure mercury ultraviolet lamp is typically used. Other types of lamps such as metahalide UV lamps and incandescent tubes can also be used. It should be noted that the liquid crystal layer surface temperature at the time of ultraviolet irradiation is appropriately adjusted by a cold mirror, water cooling or other cooling treatment, or increasing the line speed so that the liquid crystal layer surface temperature falls within the liquid crystal temperature range.

  The thickness of the optical compensation layer is not particularly limited, but is preferably adjusted in the range of usually about 0.05 to 10 μm, and more preferably 0.1 to 5 μm. Note that the optical compensation layer can be formed as a single layer or further as a multilayer.

  In the polarizing plate with an optical compensation layer of the present invention, the optical compensation layer and the polarizing plate are laminated via an adhesive layer.

  The polarizer used for the polarizing plate is not particularly limited, and various types can be used. Examples of the polarizer include a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer-based partially saponified film, and a dichromatic dye such as iodine or a dichroic dye. And uniaxially stretched by adsorbing a reactive substance, and a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride. Among these, those obtained by stretching a polyvinyl alcohol-based film and adsorbing and orienting a dichroic material (iodine, dye) are preferably used. Although the thickness of the polarizer is not particularly limited, it is generally about 5 to 80 μm.

  A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine, and stretching the film to 3 to 7 times its original length. If necessary, it can be immersed in an aqueous solution of boric acid or potassium iodide. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, dirt on the surface of the polyvinyl alcohol-based film and an anti-blocking agent can be washed, and by swelling the polyvinyl alcohol-based film, the effect of preventing unevenness such as uneven dyeing can be obtained. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. Stretching can be performed in an aqueous solution of boric acid or potassium iodide or in a water bath.

  A polarizing plate having a protective film on one or both sides of a polarizer is usually used. The protective film preferably has excellent transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, and the like. Examples of the material of the protective film include, 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, polystyrene and acrylonitrile / styrene copolymer. Styrene-based polymers such as (AS resin) and polycarbonate-based polymers. In addition, polyethylene, polypropylene, polyolefin having a cyclo- or norbornene structure, polyolefin-based polymer such as ethylene-propylene copolymer, vinyl chloride-based polymer, amide-based polymer such as nylon or aromatic polyamide, imide-based polymer, and sulfone-based polymer , 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 Blends of polymers are examples of polymers forming the protective film. In addition, a film formed from a thermosetting or ultraviolet curable resin such as an acrylic, urethane, acrylic urethane, epoxy, or silicone resin may be used.

  Further, polymer films described in JP-A-2001-343529 (WO 01/37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and (B) a thermoplastic resin having a side chain And / or an unsubstituted phenyl and a resin composition containing a thermoplastic resin having a nitrile group. A specific example is a film of a resin composition containing an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film composed of a mixed extruded product of a resin composition or the like can be used.

  As the protective film, a cellulosic polymer such as triacetyl cellulose is preferable from the viewpoints of polarization characteristics and durability. Particularly, a triacetyl cellulose film is preferable. In the case where protective films are provided on both sides of the polarizer, a protective film made of the same polymer material may be used on both sides thereof, or a protective film made of a different polymer material may be used.

  Although the thickness of the protective film can be determined as appropriate, it is generally about 10 to 500 μm from the viewpoints of strength, workability such as handleability, and thin layer properties. In particular, 20 to 300 μm is preferable, and 30 to 200 μm is more preferable.

  Further, it is preferable that the protective film has as little coloring as possible. Therefore, Rth = [(nx + ny) / 2−nz] · d (where nx and ny are the main refractive indices 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 retardation value in the film thickness direction of -90 nm to +75 nm is preferably used. By using a film having a retardation value (Rth) in the thickness direction of -90 nm to +75 nm, coloring (optical coloring) of the polarizing plate caused by the protective film can be substantially eliminated. The thickness direction retardation value (Rth) is more preferably -80 nm to +60 nm, and particularly preferably -70 nm to +45 nm.

  Usually, the polarizer and the protective film are in close contact with each other via a water-based adhesive or the like. Examples of the water-based pressure-sensitive adhesive include a polyvinyl alcohol-based pressure-sensitive adhesive, a gelatin-based pressure-sensitive adhesive, a vinyl-based latex-based, a water-based polyurethane, and a water-based polyester.

  As the protective film, a hard coat layer or a film subjected to an antireflection treatment, a treatment for preventing sticking, or a treatment for diffusion or antiglare can be used.

  The hard coat treatment is performed for the purpose of preventing scratches on the polarizing plate surface and the like.For example, an acrylic or silicone-based appropriate ultraviolet-curable resin is used to form a cured film having excellent hardness and sliding properties on the protective film. It can be formed by a method of adding to the surface. The anti-reflection treatment is performed for the purpose of preventing the reflection of external light on the polarizing plate surface, and can be achieved by forming an anti-reflection film or the like according to the related art. In addition, the anti-sticking treatment is performed for the purpose of preventing adhesion to an adjacent layer.

  The anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing plate and hindering the visibility of light transmitted through the polarizing plate, and is, for example, a roughening method using a sand blast method or an embossing method. The protective film can be formed by providing a fine uneven structure on the surface of the protective film by an appropriate method such as a method of blending transparent fine particles or the like. As the fine particles to be contained in the formation of the surface fine uneven structure, for example, a conductive material composed of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide and the like having an average particle size of 0.5 to 50 μm. Transparent fine particles such as inorganic fine particles that may be used and organic fine particles made of a crosslinked or uncrosslinked polymer or the like are used. When forming the fine surface unevenness structure, the amount of the fine particles to be used is generally about 2 to 50 parts by weight, preferably 5 to 25 parts by weight, per 100 parts by weight of the transparent resin forming the fine surface unevenness structure. The anti-glare layer may also serve as a diffusion layer (such as a viewing angle expanding function) for diffusing light transmitted through the polarizing plate to increase the viewing angle or the like.

  The anti-reflection layer, anti-sticking layer, diffusion layer, anti-glare layer and the like can be provided on the protective film itself, or can be provided as an optical layer separately from the transparent protective layer.

  Examples of the pressure-sensitive adhesive used for laminating the optical compensation layer and the polarizing plate include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, and various types of pressure-sensitive adhesives such as silicone-based pressure-sensitive adhesives. Preferably, the weight average molecular weight of the base polymer is about 300,000 to 2.5 million.

  In addition, as a monomer used for the acrylic polymer which is a base polymer of the acrylic pressure-sensitive adhesive, various (meth) acrylates ｛(meth) acrylates refer to acrylates and / or methacrylates. The following (meta) has the same meaning. You can use｝. Specific examples of the (meth) acrylate include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like. Can be used alone or in combination. Further, a small amount of (meth) acrylic acid may be used instead of a part of the (meth) acrylic acid ester in order to impart polarity to the obtained acrylic polymer. Further, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, N-methylol (meth) acrylamide, or the like may be used in combination as a crosslinkable monomer. Further, if desired, other copolymerizable monomers such as vinyl acetate and styrene may be used together to the extent that the adhesive properties of the (meth) acrylate polymer are not impaired.

  Examples of the base polymer of the rubber-based pressure-sensitive adhesive include natural rubber, isoprene-based rubber, styrene-butadiene-based rubber, recycled rubber, polyisobutylene-based rubber, styrene-isoprene-styrene-based rubber, and styrene-butadiene-styrene-based rubber. And the like. Examples of the base polymer of the silicone-based pressure-sensitive adhesive include dimethylpolysiloxane and diphenylpolysiloxane.

  Further, the pressure-sensitive adhesive can contain a crosslinking agent. Examples of the crosslinking agent include a polyisocyanate compound, a polyamine compound, a melamine resin, a urea resin, and an epoxy resin. Further, the pressure-sensitive adhesive, if necessary, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, and the like, and each may be appropriately used without departing from the object of the present invention. it can.

  The method for forming the pressure-sensitive adhesive layer is not particularly limited, and examples include a method in which a pressure-sensitive adhesive (solution) is applied on a polarizing plate or an optical compensation layer and dried, and a method in which transfer is performed using a release sheet provided with a pressure-sensitive adhesive layer. . The thickness of the pressure-sensitive adhesive layer (dry film thickness) is not particularly limited, but is preferably about 2 to 40 μm. After laminating the optical compensation layer and the polarizing plate via the pressure-sensitive adhesive layer, the alignment base material can be peeled from the optical compensation layer.

  The polarizing plate with optical compensation of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including a wavelength plate such as 1/2 or 1/4), a viewing angle compensation film, and the like are formed. One or more optical layers that may be used may be used. In particular, a reflective polarizing plate or a transflective polarizing plate in which a reflecting plate or a transflective reflecting plate is further laminated on the polarizing plate of the present invention, an elliptically polarizing plate or a circularly polarized light in which a retardation plate is further laminated on 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, or a polarizing plate in which a brightness enhancement film is further laminated on a polarizing plate is preferable.

  The reflection type polarizing plate is provided with a reflection layer on a polarizing plate, and is used to form a liquid crystal display device of a type that reflects incident light from a viewing side (display side) and displays the reflected light. There is an advantage that the built-in light source can be omitted, and the liquid crystal display device can be easily made thinner. 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 provided on 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 formed by attaching a foil or a vapor-deposited film made of a reflective metal such as aluminum to one surface of a transparent protective film that has been matted as necessary. Further, there may be mentioned, for example, a transparent protective film in which fine particles are contained to form a fine surface unevenness structure, and a reflective layer having a fine unevenness structure is formed thereon. The reflective layer having the above-mentioned fine uneven structure has an advantage of diffusing incident light by irregular reflection, preventing directivity and glare, and suppressing unevenness in brightness and darkness. Further, the transparent protective film containing fine particles also has an advantage that the incident light and the reflected light thereof are diffused when transmitting the light, and thus the unevenness of brightness and darkness can be further suppressed. The reflection layer having a fine uneven structure reflecting the fine uneven structure on the surface of the transparent protective film can be formed by, for example, making the metal transparent by an appropriate method such as an evaporation method such as a vacuum evaporation method, an ion plating method, or a sputtering method, or a plating method. It can be carried out by a method of directly attaching to the surface of the protective layer.

  The reflection plate can be used as a reflection sheet or the like in which a reflection layer is provided on an appropriate film according to the transparent film instead of the method of directly applying the reflection plate to the transparent protective film. Since the reflective layer is usually made of a metal, the use form in which the reflective surface is covered with a transparent protective film, a polarizing plate, or the like is intended to prevent a decrease in the reflectance due to oxidation and, as a result, a long-lasting initial reflectance. It is more preferable to avoid separately providing a protective layer.

  The transflective polarizing plate can be obtained by forming a transflective 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. When a liquid crystal display device or the like is used in a relatively bright atmosphere, an image is displayed by reflecting incident light from the viewing side (display side). In a relatively dark atmosphere, a liquid crystal display device of a type that displays an image using a built-in light source such as a backlight built in the back side of a transflective polarizing plate can be formed. That is, the transflective polarizing plate can save energy for use of a light source such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device of a type that 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. When changing linearly polarized light to elliptically or circularly polarized light, changing elliptically or circularly polarized light to linearly polarized light, or changing the polarization direction of linearly polarized light, a phase difference plate or the like is used. 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 converts circularly polarized light into linearly polarized light. A half-wave plate (also called a λ / 2 plate) is usually used to change the polarization direction of linearly polarized light.

  The elliptically polarizing plate compensates (prevents) coloring (blue or yellow) caused by the birefringence of the liquid crystal layer of the Spartist Nematic (STN) type liquid crystal display device, and is effectively used in the case of black-and-white display without the coloring. Can be Further, the one in which the three-dimensional refractive index is controlled is preferable because coloring which occurs when the screen of the liquid crystal display device is viewed from an oblique direction can be compensated (prevented). The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflection type liquid crystal display device that displays an image in color, and also has an antireflection function. As specific examples of the above retardation plate, polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene and other polyolefins, polyarylate, birefringent film obtained by stretching a film made of a suitable polymer such as polyamide And an alignment film of a liquid crystal polymer, and an alignment layer of a liquid crystal polymer supported by a film. The retardation plate may have an appropriate retardation depending on the purpose of use, such as, for example, a color plate due to birefringence of various wave plates or a liquid crystal layer, or a target for compensation of a viewing angle or the like. A retardation plate may be laminated to control optical characteristics such as retardation.

  Further, the elliptically polarizing plate or the reflection type elliptically polarizing plate is obtained by laminating a polarizing plate or a reflection type polarizing plate and a retardation plate in an appropriate combination. Such an elliptically polarizing plate or the like may be formed by sequentially and separately laminating a (reflection type) polarizing plate and a retardation plate in the process of manufacturing a liquid crystal display device so as to form a combination. An optical film such as a polarizing plate has an advantage that the stability of quality and laminating workability are excellent and the production efficiency of a liquid crystal display device or the like can be improved.

  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 not in a direction perpendicular to the screen but in a slightly oblique direction. Such a viewing angle compensating retardation plate includes, for example, a retardation film, an alignment film such as a liquid crystal polymer, and a transparent substrate on which an alignment layer such as a liquid crystal polymer is supported. The ordinary retardation plate is a polymer film having birefringence uniaxially stretched in the plane direction, whereas the retardation plate used as the viewing angle compensation film is biaxially stretched in the plane direction. A birefringent polymer film such as a polymer film having birefringence or a birefringent polymer such as a birefringent polymer and a birefringent polymer in which the refractive index in the thickness direction is stretched uniaxially in the plane direction and also stretched in the thickness direction and controlled in the thickness direction. Used. Examples of the obliquely oriented film include a film obtained by bonding a heat shrinkable film to a polymer film and subjecting the polymer film to a stretching treatment and / or shrinkage treatment under the action of the shrinkage force caused by heating, and a film obtained by obliquely aligning a liquid crystal polymer. No. As the raw material polymer of the retardation plate, the same polymer as described in the above retardation plate is used to prevent coloring or the like due to a change in the viewing angle based on the phase difference due to the liquid crystal cell and to enlarge the viewing angle for good visibility. Any appropriate one for the purpose can be used.

  In addition, because of achieving a wide viewing angle with good visibility, the optically-compensated retardation, in which an optically anisotropic layer consisting of an alignment layer of liquid crystal polymer, particularly a tilted alignment layer of discotic liquid crystal polymer, is supported by a triacetyl cellulose film A plate can be preferably used.

  A polarizing plate obtained by laminating a polarizing plate and a brightness enhancement film is usually used by being provided on the back side of a liquid crystal cell. The brightness enhancement film reflects linearly polarized light of a predetermined polarization axis or circularly polarized light of a predetermined direction when natural light is incident due to reflection from a backlight or a back side of a liquid crystal display device, and has a property of transmitting other light. A polarizing plate obtained by laminating a brightness enhancement film and a polarizing plate, while transmitting light from a light source such as a backlight to obtain a transmission light in a predetermined polarization state, is reflected without transmitting light other than the predetermined polarization state. You. The light reflected on the surface of the brightness enhancement film is further inverted through a reflection layer or the like provided on the rear side thereof and re-incident on the brightness enhancement film, and a part or all of the light is transmitted as light of a predetermined polarization state to thereby obtain brightness. In addition to increasing the amount of light transmitted through the enhancement film, it is also possible to improve the luminance by supplying polarized light that is hardly absorbed by the polarizer to increase the amount of light that can be used for liquid crystal display image display and the like. In other words, when light is incident through the polarizer from the back side of the liquid crystal cell with a backlight or the like without using a brightness enhancement film, light having a polarization direction that does not match the polarization axis of the polarizer is almost completely polarized. Is absorbed by the polarizer and does not pass through the polarizer. That is, although it depends on the characteristics of the polarizer used, about 50% of the light is absorbed by the polarizer, and accordingly, the amount of light available for liquid crystal image display and the like decreases, and the image becomes darker. The brightness enhancement film is such that light having a polarization direction as absorbed by the polarizer is once reflected by the brightness enhancement film without being incident on the polarizer, and further inverted through a reflection layer or the like provided behind the same. The brightness enhancement film transmits only the polarized light whose polarization direction has been changed so that the polarization direction of the light reflected and inverted between the two can pass through the polarizer. Since light is supplied to the polarizer, light from a backlight or the like 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 above-mentioned reflection layer or the like. The light in the polarization state reflected by the brightness enhancement film goes to the reflection layer and the like, but the diffuser provided uniformly diffuses the light passing therethrough, and at the same time, eliminates the polarization state and becomes a non-polarization state. That is, the diffuser returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the light in the natural light state is repeatedly directed to the reflection layer and the like, reflected through the reflection layer and the like, again passed through the diffusion plate and re-incident on the brightness enhancement film. Thus, while maintaining the brightness of the display screen by providing a diffusion plate that returns polarized light to the original natural light state between the brightness enhancement film and the reflective layer, etc., at the same time, reducing unevenness in the brightness of the display screen, A uniform and bright screen can be provided. It is considered that by providing such a diffusion plate, the number of repetitions of the reflection of the first incident light is moderately increased, and a uniform bright display screen can be provided in combination with the diffusion function of the diffusion plate.

  The brightness enhancement film has a property of transmitting linearly polarized light having a predetermined polarization axis and reflecting other light, such as a multilayer thin film of a dielectric or a multilayer laminate of thin films having different refractive index anisotropies. As shown in the figure, such as a cholesteric liquid crystal polymer oriented film or a film in which the oriented liquid crystal layer is supported on a film substrate, it exhibits a property of reflecting either left-handed or right-handed circularly polarized light and transmitting other light. Any suitable one such as one can be used.

  Therefore, in the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis, the transmitted light is incident on the polarization plate as it is, with the polarization axis aligned, thereby efficiently transmitting the light while suppressing the absorption loss by the polarization plate. Can be done. On the other hand, in a brightness enhancement film of the type that emits circularly polarized light, such as a cholesteric liquid crystal layer, it can be directly incident on a polarizer, but from the viewpoint of suppressing absorption loss, the circularly polarized light is linearly polarized through a retardation plate. It is preferable that the light is incident on a polarizing plate. By using a quarter-wave plate as the retardation plate, circularly polarized light can be converted to linearly polarized light.

  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 superimposing 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.

  The cholesteric liquid crystal layer is also configured such that two or three or more cholesteric liquid crystal layers are superimposed on each other to reflect circularly polarized light in a wide wavelength range such as a visible light region. Based on this, it is possible to obtain circularly polarized light transmitted in a wide wavelength range.

  Further, the polarizing plate may be formed by laminating a polarizing plate and two or three or more optical layers as in the above-mentioned polarized light separating type polarizing plate. Therefore, a reflective elliptically polarizing plate or a transflective elliptically polarizing plate obtained by combining the above-mentioned reflective polarizing plate, semi-transmissive polarizing plate, and retardation plate may be used.

  An optical film in which the optical layer is laminated on a polarizing plate can also be formed by a method of sequentially laminating the optical film in a manufacturing process of a liquid crystal display device or the like. It has the advantage of being excellent in stability and assembly work and can improve the manufacturing process of a liquid crystal display device and the like. Appropriate bonding means such as an adhesive layer can be used for lamination. When bonding the polarizing plate and other optical films, their optical axes can be set at an appropriate angle depending on the intended retardation characteristics and the like.

  The above-described polarizing plate or the optical film in which at least one polarizing plate is laminated may be provided with an adhesive layer for bonding to another member such as a liquid crystal cell. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited, and for example, an acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyamide, a polyether, and a polymer having a fluorine-based or rubber-based polymer as a base polymer are appropriately selected. Can be used. In particular, an acrylic adhesive having excellent optical transparency, exhibiting appropriate wettability, cohesiveness and adhesive adhesive properties and having excellent weather resistance and heat resistance can be preferably used.

  In addition to the above, prevention of foaming and peeling phenomena due to moisture absorption, reduction of optical characteristics due to thermal expansion difference and the like, prevention of warpage of the liquid crystal cell, and, in view of the formability of a liquid crystal display device having high quality and excellent durability, etc. An adhesive layer having low moisture absorption and excellent heat resistance is preferred.

  The adhesive layer is, for example, a natural or synthetic resin, in particular, a tackifier resin, or a filler, a pigment, a colorant, an antioxidant, or the like made of glass fiber, glass beads, metal powder, other inorganic powder, and the like. May be added to the pressure-sensitive adhesive layer. In addition, an adhesive layer containing fine particles and exhibiting light diffusibility may be used.

  The attachment of the adhesive layer to one or both surfaces of the polarizing plate or the optical film can be performed by an appropriate method. As an example thereof, for example, an adhesive solution of about 10 to 40% by weight is prepared by dissolving or dispersing a base polymer or a composition thereof in a solvent composed of a single solvent or a mixture of appropriate solvents such as toluene and ethyl acetate, A method of directly attaching it on a polarizing plate or an optical film by an appropriate developing method such as a casting method or a coating method, or forming an adhesive layer on a separator according to the above and forming it on a polarizing plate or an optical film. There is a method of transferring to the top.

  The pressure-sensitive adhesive layer may be provided on one or both sides of a polarizing plate or an optical film as a superposed layer of different compositions or types. When provided on both surfaces, an adhesive layer having a different composition, type, thickness, etc. may be formed on the front and back of the polarizing plate or the optical film. The thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, and the like, and is generally 1 to 500 µm, preferably 5 to 200 µm, particularly preferably 10 to 100 µm.

  A separator is temporarily attached to the exposed surface of the adhesive layer for the purpose of preventing contamination and the like until the adhesive layer is put to practical use and covered. This can prevent the adhesive layer from coming into contact with the adhesive layer in a normal handling state. Except for the above thickness conditions, the separator may be, for example, a plastic film, a rubber sheet, paper, cloth, a nonwoven fabric, a net, a foamed sheet or a metal foil, a suitable thin sheet such as a laminate thereof, or a silicone-based material as necessary. Appropriate conventional ones, such as those coated with an appropriate release agent such as a long-chain alkyl-based, fluorine-based, or molybdenum sulfide, may be used.

  In the present invention, each layer such as a polarizer, a transparent protective film, an optical film, or the like, which forms the above-described polarizing plate, and a layer such as an adhesive layer include, for example, a salicylate compound, a benzophenol compound, a benzotriazole compound, and cyanoacrylate. It may be a compound having an ultraviolet absorbing ability by a method such as a method of treating with an ultraviolet absorbent such as a system compound and a nickel complex compound.

  The polarizing plate or the optical film of the present invention can be preferably used for forming various devices such as a liquid crystal display device. The formation of the liquid crystal display device can be performed according to a conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell and a polarizing plate or an optical film and, if necessary, an illumination system and incorporating a drive circuit. There is no particular limitation except that a polarizing plate or an optical film according to the present invention is used, and it can be in accordance with the conventional art. As for the liquid crystal cell, any type such as TN type, STN type and π type can be used.

  An appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing plate or an optical film is arranged on one or both sides of a liquid crystal cell, or a lighting system using a backlight or a reflector can be formed. In that case, the polarizing plate or the optical film according to the present invention can be installed on one side or both sides of the liquid crystal cell. When a polarizing plate or an optical film is provided on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, a suitable component such as a diffusion plate, an anti-glare layer, an antireflection film, a protection plate, a prism array, a lens array sheet, a light diffusion 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 luminous body (organic electroluminescent luminous body) is formed by sequentially laminating a transparent electrode, an organic luminescent layer, and a metal electrode on a transparent substrate. 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 or the like, and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a configuration 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 a hole injection layer, a light emitting layer, and an electron injection layer thereof is known. Has been.

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

  In an organic EL display device, at least one of the electrodes must be transparent in order to extract light emitted from the organic light emitting layer. Usually, a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. 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 a metal electrode such as Mg-Ag or Al-Li is 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. Therefore, the organic light emitting layer transmits light almost completely, similarly to the transparent electrode. As a result, when light is incident from the surface of the transparent substrate during non-light emission, light transmitted through the transparent electrode and the organic light-emitting layer and reflected by the metal electrode again exits to the surface side of the transparent substrate, and when viewed from the outside, The display surface of the organic EL display device looks like a mirror surface.

  In an organic EL display device including an organic electroluminescent luminous body having a transparent electrode on the front side of an organic luminescent layer that emits light by applying a voltage and a metal electrode on the back side of the organic luminescent layer, the surface of the transparent electrode A polarizing plate can be provided on the side, and 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 polarizing function. In particular, if the phase difference plate is composed of a 1/4 wavelength plate and the angle between the polarization directions of the polarizing plate and the phase difference plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded. .

  That is, as for the external light incident on the organic EL display device, only the linearly polarized light component is transmitted by the polarizing plate. This linearly polarized light is generally converted into elliptically polarized light by a phase difference plate, but is particularly circularly polarized light when the phase difference plate is a quarter-wave plate and the angle between the polarization directions of the polarization plate and the phase difference plate is π / 4. .

  This circularly polarized light transmits through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate again, and becomes linearly polarized light again by the phase difference plate. The linearly polarized light cannot pass through the polarizing plate because it is orthogonal to the polarizing direction of the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

  Hereinafter, examples and the like that specifically show the configuration and effects of the present invention will be described. All parts and percentages in each case are by weight. The direction in which the in-plane refractive index in the film plane is the maximum is the X axis, the direction perpendicular to the X axis is the Y axis, the refractive index in the thickness direction of the film is the Z axis, and refraction at 590 nm in each axial direction. When the ratio is nx, ny, nz, and the thickness d (nm) of the film, the in-plane retardation = (nx−ny) × d, and the retardation in the thickness direction = {(nx + ny) / 2−nz} × d. Is a value measured by an automatic birefringence meter (KOBRA manufactured by Oji Scientific Instruments).

Example 1
70 parts of a polymerizable rod-shaped nematic liquid crystal material represented by the following chemical formula 1, 30 parts of a polymerizable material having a chiral structure represented by the following chemical formula 2, and a polymerizable material (polyethylene glycol) having a soft segment represented by the following chemical formula 3 1 part of diacrylate) and 3 parts of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals) were dissolved in toluene to obtain a toluene solution adjusted to have a solid concentration of 30%.

  This toluene solution was coated on a biaxially stretched 50 μm-thick polyethylene terephthalate film as an alignment base material using a bar coater, treated at 70 ° C. for 5 minutes, and dried and aligned. This was fixed by performing photopolymerization using a high-pressure mercury lamp to obtain a cholesteric-oriented optical compensation layer having a thickness of 5 μm. The helix pitch was 0.08 μm. When the obtained optical compensation layer was transferred to a glass plate using an adhesive and the retardation value was determined, it was an optical compensation layer having an in-plane retardation of 1 nm and a thickness direction retardation of 200 nm. After bonding the optical compensation layer to the pressure-sensitive adhesive layer of an adhesive polarizing plate (SEG1425DU, manufactured by Nitto Denko Corporation), the alignment substrate was peeled off from the optical compensation layer to obtain a polarizing plate with an optical compensation layer. The thickness of the polarizing plate is 180 μm, and the thickness of the pressure-sensitive adhesive layer is 25 μm.

Example 2
A toluene solution was obtained in the same manner as in Example 1 except that 1 part of polypropylene glycol diacrylate represented by the following formula 4 was used as the polymerizable material having a soft segment.

  Using the toluene solution, an optical compensation layer was formed in the same manner as in Example 1, and a polarizing plate with an optical compensation layer was obtained in the same manner as in Example 1.

Comparative Example 1
A toluene solution was obtained in the same manner as in Example 1 except that the polymerizable material having a soft segment was not used in preparing the toluene solution. Further, using the toluene solution, an optical compensation layer was formed in the same manner as in Example 1, and a polarizing plate with an optical compensation layer was obtained.

(Evaluation)
The polarizing plate with an optical compensation layer obtained in each of Examples and Comparative Examples was cut into a 25 mm-wide strip. With the optical compensation layer facing outward, it was wound around a cylindrical glass tube having a radius of 25 mm to 10 mm at room temperature (23 ° C.), held for 30 seconds, removed, and visually checked for cracks in the optical compensation layer. Table 1 shows the results.

表１から、実施例では、光学補償層形成材に、ソフトセグメントを有する重合性材料を含ませることで、曲率半径が１０ｍｍとなるように屈曲させた場合にも光学補償層に割れが発生していない光学補償層付偏光板が得られていることが認められる。したがって、本発明の光学補償層付偏光板は、実質的に各工程におけるハンドリングで、光学補償層の割れを防止できることが分かる。

From Table 1, in Examples, the optical compensation layer forming material contains a polymerizable material having a soft segment, so that even when the optical compensation layer is bent to have a radius of curvature of 10 mm, cracks occur in the optical compensation layer. It can be seen that a polarizing plate with an optical compensation layer not obtained was obtained. Therefore, it can be seen that the polarizing plate with an optical compensation layer of the present invention can prevent cracking of the optical compensation layer by handling in each step substantially.

Claims (9)

  An optical compensation layer forming material comprising a polymerizable liquid crystal material and a polymerizable material having a soft segment.   The optical compensation layer forming material according to claim 1, wherein the polymerizable material having a soft segment is polyethylene glycol diacrylate.   An optical compensation layer, wherein the optical compensation layer forming material according to claim 1 or 2 is fixed by polymerization after orientation. After aligning the optical compensation layer forming material containing a polymerizable liquid crystal material, the optical compensation layer and the polarizing plate fixed by polymerization and the polarizing plate with an optical compensation layer is laminated via an adhesive layer,
A polarizing plate with an optical compensation layer, wherein the optical compensation layer forming material contains a polymerizable material having a soft segment. After aligning the optical compensation layer forming material containing a polymerizable liquid crystal material, the optical compensation layer and the polarizing plate fixed by polymerization and the polarizing plate with an optical compensation layer is laminated via an adhesive layer,
The polarizing plate with an optical compensation layer, wherein the polarizing plate with the optical compensation layer is bent so that the radius of curvature is 10 mm with the optical compensation layer being on the outside and held for 30 seconds, so that the optical compensation layer does not crack. .   The polarizing plate with an optical compensation layer according to claim 5, wherein the optical compensation layer forming material contains a polymerizable material having a soft segment.   7. The polarizing plate with an optical compensation layer according to claim 4, wherein the polymerizable material having a soft segment is polyethylene glycol diacrylate.   An optical film, wherein at least one of the optical compensation layer according to claim 3 and the polarizing plate with an optical compensation layer according to any one of claims 4 to 7 is used.   An image display device using the optical compensation layer according to claim 3, the polarizing plate with the optical compensation layer according to claim 4, or the optical film according to claim 8.