JP2010211196A - Polarizer, and liquid crystal panel and liquid crystal display device each including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizer capable of obtaining a video of high quality when using it for a liquid crystal display device, especially a polarizer for backside disposition arranged between a liquid crystal cell and a backlight, and to provide a liquid crystal panel and a liquid crystal display device each including the polarizer. <P>SOLUTION: The polarizer for backside disposition includes: a polarizing film constituted of a uniaxially stretched polyvinyl alcohol resin film having iodine or a dichroic dye adsorbed thereon and oriented; and a resin film laminated on at least one side of the polarizing film. When the surface of the resin film on the side opposite to the polarizing film is rubbed with steel wool so as to make ten reciprocations under the conditions of a load of 250 g/cm<SP>2</SP>, a stroke width of 5 cm, and a rate of 50 reciprocations/min, then the surface has ten scratches or less. The liquid crystal panel and the liquid crystal display device each including the polarizer are provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polarizing plate including a resin film laminated on one side or both sides of a polarizing film, and a liquid crystal panel and a liquid crystal display device using the polarizing plate.

  Applications of liquid crystal display devices are rapidly expanding as thin display devices such as liquid crystal televisions, liquid crystal monitors, and personal computers. In particular, the market for liquid crystal televisions is remarkably expanding, and the demand for cost reduction is very high.

  A normal liquid crystal display device includes a backlight composed of a cold cathode tube or an LED, a light diffusion plate, one or more light diffusion sheets, a back side polarizing plate, a liquid crystal cell, and a viewing side polarizing plate. A condensing sheet may be further disposed between the backlight and the back-side polarizing plate. In the use of large-screen liquid crystal televisions, the needs for wall-mounted televisions have become apparent due to thinning. In this case, it is necessary to reduce the number of members and the number of members used in response to the thinning of liquid crystal televisions. In response to such demands, one or more light diffusing sheets are omitted by reducing the number of parts by providing light diffusibility to the back side polarizing plate itself disposed between the liquid crystal cell and the backlight. The technique to do is known (for example, patent documents 1-6).

JP-A-11-183712 JP 2000-75133 A JP 2000-75134 A JP 2000-75135 A JP 2000-75136 A JP 2000-75137 A

  For example, Patent Document 5 described above has a light diffusion layer in close contact with one or both sides of a polarizing plate, and the light diffusion layer has a fine concavo-convex structure with a center line average roughness of 0.3 μm or more on the outer surface. A light diffusion polarizing plate having a surface hardness of pencil hardness H or less is disclosed. Further, it is described that by controlling the surface hardness of the light diffusing layer to be H or less, the optical member such as a light collecting sheet disposed on the polarizing plate can be prevented from being damaged.

  However, in the conventional light diffusing polarizing plate used as the back side polarizing plate, the scratch resistance of the surface of the polarizing plate itself is not taken into consideration, and in the liquid crystal display device, the light diffusing on the light diffusing polarizing plate is not considered. When optical members such as plates, light diffusing sheets, and light condensing sheets are stacked, the surface of the light diffusing polarizing plate is damaged due to contact with the optical members, and the image quality of the liquid crystal display device is adversely affected. was there.

  Accordingly, an object of the present invention is to provide a polarizing plate that can obtain a high-quality image when it is used as a liquid crystal display device, particularly a back-side polarizing plate disposed between a liquid crystal cell and a backlight. . Another object of the present invention is to provide a liquid crystal panel and a liquid crystal display device using the polarizing plate.

The present invention provides a liquid crystal display device comprising: a polarizing film comprising a uniaxially stretched polyvinyl alcohol resin film in which iodine or a dichroic dye is adsorbed and oriented; and a resin film laminated on at least one surface of the polarizing film. A polarizing plate used as a back side polarizing plate disposed between a liquid crystal cell and a backlight is provided. Here, the hardness (hereinafter also referred to as steel wool hardness) of the surface (outer surface) opposite to the side facing the polarizing film in the resin film is such that the surface is made of steel wool and the load is 250 g / cm ^2. When expressed as the number of scratches when 10 strokes are rubbed under the conditions of a stroke width of 5 cm and a speed of 50 cycles / min, the number is 10 or less. Moreover, it is preferable that the pencil hardness of the surface (outer surface) on the opposite side to the side which opposes the polarizing film in this resin film is H or less. The resin film is preferably a diffusion film having light diffusibility.

  The said resin film can be used as the film which the one surface has an uneven | corrugated shape. For example, one surface of the resin film is a smooth surface having a 10-point average roughness of less than 0.1 μm, and the other surface is an uneven surface having a 10-point average roughness of 0.1 μm or more.

  The polarizing plate of this invention may be equipped with the optical compensation film or protective film laminated | stacked on the surface on the opposite side to the surface where the resin film in a polarizing film is laminated | stacked.

  Further, according to the present invention, there is provided a liquid crystal panel comprising a liquid crystal cell and the polarizing plate of the present invention laminated on the liquid crystal cell, wherein the polarizing plate has a surface on which the resin film in the polarizing film is laminated, A liquid crystal panel is provided in which the opposite surface faces the liquid crystal cell.

  Furthermore, according to the present invention, there is provided a liquid crystal display device comprising a backlight, a light diffusing plate and the liquid crystal panel of the present invention in this order, wherein the liquid crystal panel has a resin film of a polarizing plate facing the light diffusing plate. Liquid crystal display device, and a liquid crystal display device comprising a backlight, a light diffusion plate, a light diffusion sheet, and the liquid crystal panel of the present invention in this order, wherein the liquid crystal panel is a resin film of a polarizing plate Is provided so as to face the light diffusion sheet.

  According to the polarizing plate and the liquid crystal panel of the present invention, since the resin film side surface of the polarizing plate is sufficiently strong against scratches, optical members such as a light diffusing plate, a light diffusing sheet, and a light collecting sheet are stacked on the polarizing plate. In this case, the polarizing plate can be effectively suppressed or prevented from being damaged. Therefore, according to the polarizing plate and the liquid crystal panel of the present invention, it is possible to provide a liquid crystal display device excellent in image quality without causing scratches or unevenness in the image of the liquid crystal display device to which the polarizing plate and the liquid crystal panel are applied. Moreover, according to the present invention, it is possible to reduce the thickness of the liquid crystal display device and the number of members. Such a liquid crystal display device of the present invention can be suitably applied to a liquid crystal display device for a large-screen liquid crystal television, particularly a liquid crystal display device for a liquid crystal television that can be wall-mounted.

<Polarizing plate>
The polarizing plate of this invention is arrange | positioned between the liquid crystal cell and backlight of a liquid crystal display device provided with the polarizing film which consists of a polyvinyl alcohol-type resin film, and the resin film laminated | stacked on the single side | surface or both surfaces of a polarizing film. The present invention relates to a back side polarizing plate. A resin film is normally laminated | stacked on a polarizing film through an adhesive bond layer. Hereinafter, the polarizing plate of the present invention will be described in more detail.

(Polarizing film)
Specifically, the polarizing film used in the polarizing plate of the present invention is obtained by adsorbing and orienting a dichroic dye on a uniaxially stretched polyvinyl alcohol resin film. As the polyvinyl alcohol resin constituting the polyvinyl alcohol resin film, a saponified polyvinyl acetate resin can be used. Polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymers. Etc. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

  The degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, for example, polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like can be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1000 to 10000, preferably about 1500 to 5000.

  What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of a polarizing film. The method for forming the polyvinyl alcohol-based resin is not particularly limited, and can be formed by a conventionally known appropriate method. Although the film thickness of the raw film which consists of polyvinyl alcohol-type resin is not specifically limited, For example, it is about 10-150 micrometers.

  A polarizing film is usually a process of dyeing an original film made of polyvinyl alcohol resin as described above with a dichroic dye and adsorbing the dichroic dye (dyeing process), and the dichroic dye is adsorbed. The polyvinyl alcohol-based resin film is produced through a step of treating with a boric acid aqueous solution (boric acid treatment step) and a step of washing with water after the treatment with the boric acid aqueous solution (water washing treatment step).

  Further, in the production of the polarizing film, the polyvinyl alcohol-based resin film is usually uniaxially stretched, but this uniaxial stretching may be performed before the dyeing treatment step or during the dyeing treatment step, It may be performed after the dyeing process. When uniaxial stretching is performed after the dyeing treatment step, this uniaxial stretching may be performed before the boric acid treatment step or during the boric acid treatment step. Of course, it is also possible to perform uniaxial stretching in these plural stages. Uniaxial stretching may be performed uniaxially between rolls having different peripheral speeds, or may be performed uniaxially using a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen with the solvent may be sufficient. The draw ratio is usually about 3 to 8 times.

  The dyeing of the polyvinyl alcohol-based resin film with the dichroic dye in the dyeing treatment step is performed, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing the dichroic dye. As the dichroic dye, for example, iodine, a dichroic dye or the like is used. Examples of dichroic dyes include C.I. I. Dichroic direct dyes composed of disazo compounds such as DIRECT RED 39, and dichroic direct dyes composed of trisazo, tetrakisazo compounds and the like are included. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.

  When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually 0.5 to 20 parts by weight per 100 parts by weight of water. . When iodine is used as the dichroic dye, the temperature of the aqueous solution used for dyeing is usually 20 to 40 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 20 to 1800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution, usually, 1 × 10 ^-4 to 10 parts by weight per 100 parts by weight of water, preferably 1 × 10 ^-3 to 1 parts by weight, particularly preferably 1 × 10 ^{- 3} to 1 × 10 ⁻² parts by weight. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. When using a dichroic dye as the dichroic dye, the temperature of the aqueous dye solution used for dyeing is usually 20 to 80 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 10 to 1800 seconds. is there.

  The boric acid treatment step is performed by immersing a polyvinyl alcohol-based resin film dyed with a dichroic dye in a boric acid-containing aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is usually 2 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye in the dyeing process described above, the boric acid-containing aqueous solution used in this boric acid treatment process preferably contains potassium iodide. In this case, the amount of potassium iodide in the boric acid-containing aqueous solution is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C.

  In the subsequent washing process, the polyvinyl alcohol-based resin film after the boric acid treatment described above is washed with water, for example, by immersing it in water. The water temperature in the water washing treatment is usually 5 to 40 ° C., and the immersion time is usually 1 to 120 seconds. After the water washing treatment, a drying treatment is usually performed to obtain a polarizing film. The drying process can be performed using, for example, a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually 30 to 100 ° C, preferably 50 to 80 ° C. The time for the drying treatment is usually 60 to 600 seconds, preferably 120 to 600 seconds.

  Thus, a polarizing film is obtained by subjecting the polyvinyl alcohol-based resin film to uniaxial stretching, dyeing with a dichroic dye, boric acid treatment and water washing treatment. The thickness of this polarizing film is usually in the range of 5 to 40 μm.

(Resin film)
The resin film preferably used for the polarizing plate of the present invention is a diffusion film having light diffusibility. Since a light diffusing function is imparted to the polarizing plate by using a diffusion film having light diffusibility, when this is used as a back side polarizing plate of a liquid crystal display device, it is disposed between the liquid crystal cell and the backlight. One or more light diffusion sheets can be omitted. Here, the resin film “has light diffusibility” means that incident light (typically light from a backlight) is incident from one side of the resin film and passed through the resin film. This means that transmitted light is also observed in a plurality of directions different from the linear transmission direction (straight direction of incident light) on the other surface side of the resin film.

  As the diffusion film having light diffusivity, for example, a resin film having one surface having a smooth surface and the other surface having an irregular uneven shape can be used. Here, “smooth surface” means that the ten-point average roughness Rz measured according to JIS B 0601-1994 is less than 0.1 μm, and “uneven surface” means JIS B 0601-. It means that the ten-point average roughness Rz measured according to 1994 is 0.1 μm or more. In order to obtain better light diffusibility, the ten-point average roughness Rz of the uneven surface is preferably 0.5 μm or more. Further, if the 10-point average roughness Rz is too large, the thickness of the entire film increases, which is not preferable from the viewpoint of productivity. Therefore, the 10-point average roughness Rz is preferably 50 μm or less, more preferably 20 μm or less. It is.

  When a resin film (diffusion film) whose one surface is an uneven surface is laminated on a polarizing film, the resin film may be laminated so that the uneven surface faces the polarizing film, or the smooth surface is on the polarizing film. You may laminate | stack so that it may oppose. Any lamination method can impart a light scattering function to the polarizing plate.

  The base material of the said diffusion film is not specifically limited, Various materials can be used. For example, synthetic polymers such as polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, norbornene resin, polyurethane, polyacrylate, polymethyl methacrylate; natural polymers such as cellulose diacetate and cellulose triacetate The transparent polymer material can be used. These polymer materials can contain additives such as ultraviolet absorbers, antioxidants, and plasticizers as necessary.

  As a method for producing a diffusion film using these transparent polymer materials as a base material, for example, a method for containing a diffusing agent in the base film; a method for providing a layer containing a diffusing agent on one side of the base film surface A method of roughening one side of the substrate film surface (giving surface irregularities), and the like. Each of these methods may be used alone, or two or more methods may be used in combination.

  When adopting a method of incorporating a diffusing agent in the base film, the diffusing agent is kneaded in advance into the transparent polymer material to be the base material, and then formed into a film by the casting method or the extrusion method. That's fine. In this case, for example, as a pair of rolls of the cooling roll unit, a diffusion film in which one surface is an uneven surface and the other surface is a smooth surface by using a roll having surface unevenness and a roll having a flat surface. Can be obtained.

  When adopting a method of applying a layer containing a diffusing agent on one side of the base film surface, first, the transparent polymer material was formed into a film by a casting method or an extrusion method, and then the diffusing agent was dispersed. A diffusion film can be manufactured by applying a resin liquid on a base film and drying or curing the resin liquid. Alternatively, from a multilayer structure in which a layer containing a diffusing agent is laminated on a base film by a co-extrusion method using a transparent polymer material to be a base film and a transparent polymer material kneaded in advance with a diffusing agent. A diffusion film can also be produced. In the case of these methods, the surface of the layer containing the diffusing agent is usually an uneven surface.

  Also, when adopting a method of roughening the surface of the base film, first, the transparent polymer material is formed into a sheet shape by a casting method or an extrusion method, and then, an embossing roll embossing method or sand blasting. The diffusion film can be produced by roughening the surface by the method.

  The diffusing agent is not particularly limited as long as it is colorless or white particles, and either organic particles or inorganic particles can be used. Examples of the organic particles include polyolefin resins such as polystyrene, polyethylene, and polypropylene; particles made of a polymer compound such as an acrylic resin, and may be a crosslinked polymer. A copolymer obtained by copolymerizing two or more monomers selected from ethylene, propylene, styrene, methyl methacrylate, benzoguanamine, formaldehyde, melamine, butadiene, and the like can also be used. Examples of the inorganic particles include particles made of silica, silicone, titanium oxide, and the like, and glass beads may be used.

  Examples of the resin liquid used in the method of coating the base film with the resin liquid in which the diffusing agent is dispersed include a solvent volatile or water volatile resin liquid, and a thermosetting or photocurable resin liquid. Can be used. Solvent volatile or water volatile resin liquids include polymers such as polyacrylate, polymethacrylate, polyvinyl chloride, polyvinyl acetate, cellulose, synthetic rubber, alcohols such as methanol, ethanol, propanol, and isopropanol; methyl Cellosolves such as cellosolve and ethyl cellosolve; aromatic solvents such as toluene and xylene; those dissolved or dispersed in organic solvents such as ethyl acetate and methylene chloride; or water can be used. When these solvent volatile type or water volatile type resin liquids are coated on the base film, the organic solvent or water is volatilized by drying to form a film. As the thermosetting resin liquid, a resin liquid obtained by mixing a liquid composed of a compound having an epoxy group and a compound condensed with an epoxy group such as an amine can be used. Photocurable resin liquids include resin liquids in which known radical photopolymerization initiators are added to compounds having acrylate groups, methacrylate groups, aryl groups, etc., or known photocationic polymerization to compounds having vinyl ether groups or epoxy groups. A resin liquid to which an initiator is added can be used. Additives such as ultraviolet absorbers and antioxidants can be added to these resin liquids as necessary.

  The haze value of the diffusion film is preferably 5% or more, and more preferably 15% or more and 90% or less in order to impart a good light diffusion function to the polarizing plate. More preferably, it is 45% or more and 90% or less. The haze of the diffusion film is measured according to JIS K 7136. Moreover, when a polarizing plate is arrange | positioned at a liquid crystal display device, a diffusion film with a high total light transmittance is so preferable that the brightness | luminance on a display screen becomes high enough. Specifically, the total light transmittance of the diffusion film is preferably 70% or more, more preferably 80% or more, and particularly preferably 85% or more. The total light transmittance of the diffusion film is measured according to JIS K 7361.

  The thickness of the diffusion film is not particularly limited, but is preferably about 20 μm or more and 200 μm or less, and more preferably 30 μm or more and 100 μm or less, from the viewpoint of reducing the thickness and weight of the polarizing plate.

  Moreover, in the polarizing plate of the present invention, as the resin film laminated on the polarizing film, a resin film having one surface that is a smooth surface and the other surface that has a regular uneven shape may be used. it can. When incident light is incident from one surface side of such a resin film and passed through the resin film, basically, the linear transmission direction (straight direction of incident light) on the other surface side of the resin film is Transmitted light is observed in one different direction. Examples of the regular concavo-convex shape include a lenticular shape, a prism shape, and a Fresnel shape. According to the polarizing plate using the resin film having such a regular surface uneven shape, the light emission direction can be adjusted and the luminance can be increased by condensing. Can be omitted.

  The resin film having a regular surface irregularity shape can be produced by a method such as a photopolymer process method, a profile extrusion method, a press molding method, an injection molding method, or a roll transfer method. As the substrate, the same transparent polymer material as that of the diffusion film can be used.

  Among the above, the resin film laminated on the polarizing film is preferably a diffusion film having light diffusibility.

Here, as for the said resin film laminated | stacked on a polarizing film, the surface (outer surface) on the opposite side to the side which opposes the polarizing film shows specific steel wool hardness. Specifically, using a # 0000 steel wool, load 250 g / cm ^2, stroke width 5 cm, under the conditions of speed of 50 reciprocations / min, the number of scratches when 10 rubs the outer surface of the resin film The number is 10 or less, preferably 3 or less, and more preferably 0. By using such a resin film showing steel wool hardness, the resin film surface comes to have sufficient scratch resistance, and when it is a liquid crystal display device, a light diffusion plate adjacent to the resin film of the polarizing plate, It is possible to prevent the resin film surface from being damaged by other optical members such as a light diffusion sheet and a light collecting sheet. Thereby, it is possible to obtain excellent image quality without causing scratches or unevenness in the image of the liquid crystal display device.

  In order to effectively prevent other optical members such as a light diffusing plate, a light diffusing sheet, and a light collecting sheet adjacent to the resin film of the polarizing plate in a liquid crystal display device from being damaged by the resin film. In the resin film, it is preferable that the pencil hardness of the surface (outer surface) opposite to the side facing the polarizing film is H or less. By setting the pencil hardness to H or less, it is possible to effectively prevent the resin film from damaging the surface of another optical member laminated thereon. In addition, the pencil hardness of the resin film surface is measured according to JIS K 5600-5-4.

  For the resin film showing steel wool hardness and / or pencil hardness as described above, in particular, a diffusion film, an appropriate method is selected from the above-described methods for producing the resin film. For example, the type of base material of the resin film, It can be obtained by adjusting the type of diffusing agent, the type of resin component (including a resin precursor such as a monomer component) contained in the resin liquid in which the diffusing agent is dispersed. Preferable specific examples include, for example, an ultraviolet curable hard coat resin liquid (ultraviolet curable type) in which a transparent resin film such as polyester or acrylic is used as a base film, and a diffusing agent is dispersed on the base film. A resin composition) is applied, and the resin liquid layer is cured by ultraviolet irradiation. Examples of the ultraviolet curable hard coat resin liquid include a compound having one polymerizable carbon-carbon double bond such as an acrylate group or a methacrylate group (for example, a monofunctional (meth) acrylate), and a polymerizable carbon-carbon double bond. An ultraviolet curable resin composition containing a crosslinkable compound having two or more (for example, polyfunctional (meth) acrylate) and a photopolymerization initiator can be suitably used.

  More specifically, in order for the resin film to exhibit the steel wool hardness and / or pencil hardness as described above, the cured product of the ultraviolet curable resin composition preferably has a higher hardness. As the resin composition, those having a polyfunctional monomer as a curing component are preferably used. The polymerizable functional group possessed by the polyfunctional monomer is preferably a group having a polymerizable carbon-carbon double bond, and examples thereof include acryloyl group, methacryloyl group, vinyl group and allyl group, and acryloyl group. A methacryloyl group is preferred.

  Specific examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate. , Polyol poly (meth) acrylates such as dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,3,5-cyclohexanetriol tri (meth) acrylate; bisphenol A diglycidyl ether di ( Epoxy (meth) acrylates such as meth) acrylate and di (meth) acrylate of hexanediol diglycidyl ether; polyisocyanate and hydroxyethyl ( And urethane (meth) acrylates obtained by reaction of the hydroxyl group-containing (meth) acrylate of data) acrylate.

  A monofunctional monomer can be added to the polyfunctional monomer as necessary to adjust the elastic modulus of the hard coat layer or improve adhesion, but the monofunctional monomer in the entire monomer can be added. The proportion is preferably 50% by weight or less, and more preferably 20% by weight or less. If the ratio of the monofunctional monomer is too large, the desired hardness cannot be obtained.

As a base film, the one where the hardness is low is preferable. The hardness here refers to the strength against indentation, and is represented by an index such as Vickers hardness, universal hardness, Martens hardness, and the like. By using a base film having a low hardness, the resin film is easily deformed with respect to an external force, so that an appropriate pencil hardness can be exhibited, and thus a desired effect can be obtained. The hardness of the base film is preferably 130 N / mm ² or less, more preferably 90 N / mm ² or less, using Martens hardness as an index. As such a base film, for example, polyester films such as polyethylene terephthalate, acrylic films such as polymethyl methacrylate and methyl methacrylate-styrene copolymers, and polyolefin films such as polyethylene and polypropylene are preferably used. The thickness is preferably about 20 μm to 200 μm. Even when using a base film having a low hardness, by using a polyfunctional monomer as a curing component as an ultraviolet curable resin composition, the obtained resin film can exhibit a sufficient steel wool hardness, As a result, a desired effect can be obtained.

  In selecting the combination of the base film constituting the resin film and the ultraviolet curable resin composition, it is preferable to first select the base film exhibiting the appropriate hardness as described above. Evaluation of pencil hardness and steel wool hardness is performed on a resin film obtained by coating and curing an arbitrary ultraviolet curable resin composition on the selected substrate film. As a result, if the steel wool hardness is less than the desired hardness, for example, an ultraviolet curable resin composition having a higher ratio of polyfunctional monomers compared to the above, or a higher number of functional groups per molecule. The steel wool hardness of the resin film can be increased by coating and curing the ultraviolet curable resin composition containing the increased polyfunctional monomer on the base film. In addition, when an ultraviolet curable resin composition having an acryloyl group or a methacryloyl group as a polymerizable functional group is used, UV curing can be performed while blocking oxygen, which is a suitable means for increasing the steel wool hardness of the resulting resin film. It is. If necessary, a resin film having a desired steel wool hardness can be obtained by combining these, or using an ultraviolet curable resin composition having a higher polyfunctional monomer ratio or a higher number of functional groups per molecule. Examples of the method for blocking oxygen include a method of curing in a nitrogen atmosphere, and a method of pressing a resin or metal against the coating surface of the ultraviolet curable resin composition and curing in that state.

In addition, the desired steel wool hardness obtained by selecting the combination of the base film and the UV curable resin composition in the above procedure (the surface of the resin film is steel wool, the load is 250 g / cm ² , the stroke width is 5 cm, A resin film showing 10 or less when expressed by the number of scratches when subjected to 10 reciprocating frictions at a speed of 50 reciprocations / minute usually shows a desired pencil hardness (pencil hardness H or less). When the desired pencil hardness range is not reached, it can be adjusted by reducing the use ratio of the polyfunctional monomer within a range that does not affect the steel wool hardness.

  An adhesive or pressure-sensitive adhesive layer for bonding the liquid crystal cell and the polarizing plate may be formed on the surface of the polarizing film opposite to the surface on which the resin film is bonded. In addition, a transparent film such as a protective film or an optical compensation film is laminated on the surface of the polarizing film opposite to the surface on which the resin film is bonded, and an adhesive or pressure-sensitive adhesive layer is formed on the transparent film. May be. Examples of the transparent film include cellulose resin films such as a triacetyl cellulose film (TAC film), olefin resin films, acrylic resin films, and polyester resin films such as polyethylene terephthalate. Furthermore, an optical functional film described later can be laminated on the transparent film, and an adhesive or pressure-sensitive adhesive layer can be formed on the optical functional film.

  The cellulose resin constituting the cellulose resin film means a partially esterified product or a completely esterified product of cellulose, and examples thereof include cellulose acetate ester, propionate ester, butyrate ester, and mixed esters thereof. be able to. More specifically, triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate and the like can be mentioned. When such a cellulose resin is formed into a film, a known method such as a solvent casting method or a melt extrusion method is appropriately used. Cellulosic resin films can be obtained commercially, for example, “Fujitac TD80” (Fuji Film Co., Ltd.), “Fujitac TD80UF” (Fuji Film Co., Ltd.), “Fujitac TD80UZ” (Fuji Film ( Co., Ltd.), “KC8UX2M” (manufactured by Konica Minolta Opto), “KC8UY” (manufactured by Konica Minolta Opto), and the like.

  Moreover, as an optical compensation film comprising a cellulose resin film, for example, a film containing a compound having a retardation adjusting function in the cellulose resin film; a compound having a retardation adjusting function is applied to the surface of the cellulose resin film. And a film obtained by uniaxially or biaxially stretching a cellulose resin film. As an optical compensation film made of a commercially available cellulose-based resin film, for example, “WV film Wide View Film“ WV BZ 438 ””, “WV film Wide View Film“ WV EA ”” manufactured by Fuji Film Co., Ltd., Konica Minolta Examples thereof include “KC4FR-1” and “KC4HR-1” manufactured by Opto Corporation.

  The thickness of the protective film or optical compensation film made of a cellulose resin film is not particularly limited, but is preferably in the range of 20 to 90 μm, and more preferably in the range of 30 to 90 μm. When the thickness is less than 20 μm, it is difficult to handle the film. On the other hand, when the thickness exceeds 90 μm, the workability is inferior, and it is disadvantageous in reducing the thickness and weight of the resulting polarizing plate.

  Examples of the optical compensation film made of the olefin resin film include a uniaxially stretched or biaxially stretched cycloolefin resin film. When the polarizing plate of the present invention is used for a liquid crystal panel for a large-sized liquid crystal television, particularly a liquid crystal panel having a vertical alignment (VA) mode liquid crystal cell, the above-mentioned optical compensation film is a stretched product of a cycloolefin resin film, It is also suitable from the viewpoint of optical characteristics and durability. Here, the cycloolefin resin film is a film made of a thermoplastic resin having a unit of a monomer made of a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene monomer. The cycloolefin-based film may be a hydrogenated product of a ring-opening polymer using a single cycloolefin or a ring-opening copolymer using two or more kinds of cycloolefins. It may also be an addition copolymer with an aromatic compound having a vinyl group. Further, those having a polar group introduced into the main chain or side chain are also effective.

  Commercially available thermoplastic cycloolefin-based resins include “Topas” sold by Ticona, Germany, “Arton” sold by JSR Corporation, and “Zeonor” sold by Nippon Zeon Corporation. ZEONOR ”and“ ZEONEX ”,“ APEL ”(both trade names) sold by Mitsui Chemicals, Inc., and the like, which can be suitably used. A cycloolefin resin film can be obtained by forming such a cycloolefin resin. As a film forming method, a known method such as a solvent casting method or a melt extrusion method is appropriately used. Also, for example, “Essina” and “SCA40” sold by Sekisui Chemical Co., Ltd., “Zeonor Film” sold by Optes Co., Ltd., “Arton Film” sold by JSR Co., Ltd. Cycloolefin-based resin films (such as trade names) are also commercially available, and these can also be suitably used.

  If the thickness of the optical compensation film made of a stretched cycloolefin-based resin film is too thick, the processability will be inferior, and the transparency will be reduced, and it will be disadvantageous in reducing the thickness and weight of the polarizing plate. It is preferable that it is about 20-80 micrometers.

  An adhesive is usually used for bonding the polarizing film and the resin film and bonding the protective film or the optical compensation film and the polarizing film which are laminated as necessary. When a protective film or optical compensation film is bonded to the polarizing film, the adhesive used for bonding the resin film and the adhesive used for bonding the protective film or optical compensation film are the same type of adhesive. It may be a different type of adhesive. Examples of the adhesive used for laminating these films include water-based adhesives, that is, adhesive components dissolved in water or dispersed in water. For example, a resin composition using a polyvinyl alcohol-based resin or a urethane resin as an adhesive component is a preferable adhesive.

  When a polyvinyl alcohol resin is used as the adhesive component, the polyvinyl alcohol resin is not only partially saponified polyvinyl alcohol and completely saponified polyvinyl alcohol, but also carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, and methylol group-modified polyvinyl. It may be a modified polyvinyl alcohol resin such as alcohol or amino group-modified polyvinyl alcohol. Usually, an adhesive having a polyvinyl alcohol resin as an adhesive component is prepared as an aqueous solution of a polyvinyl alcohol resin. The density | concentration of the polyvinyl alcohol-type resin in an adhesive agent is 1-10 weight part normally with respect to 100 weight part of water, Preferably it is 1-5 weight part.

  In order to improve the adhesiveness, it is preferable to add a curable component such as glyoxal or a water-soluble epoxy resin and a crosslinking agent to the adhesive having a polyvinyl alcohol resin as an adhesive component. As the water-soluble epoxy resin, for example, a polyamide polyamine epoxy resin obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a polycarboxylic acid such as adipic acid and epichlorohydrin. Can be suitably used. Commercially available products of such polyamide polyamine epoxy resins include “Smiles Resin 650” (manufactured by Sumika Chemtex Co., Ltd.), “Smiles Resin 675” (manufactured by Sumika Chemtex Co., Ltd.), and “WS-525” (Japan). PMC Co., Ltd.). The addition amount of these curable component and crosslinking agent (when added together, the total amount) is usually 1 to 100 parts by weight, preferably 1 to 50 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin. . When the addition amount of the curable component and the crosslinking agent is less than 1 part by weight with respect to 100 parts by weight of the polyvinyl alcohol-based resin, the effect of improving adhesiveness tends to be reduced, and the curable component, When the addition amount of the crosslinking agent exceeds 100 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin, the adhesive layer tends to become brittle.

  When a urethane resin is used as the adhesive component, examples of a suitable adhesive composition include a mixture of a polyester ionomer type urethane resin and a compound having a glycidyloxy group. Here, the polyester ionomer type urethane resin is a urethane resin having a polyester skeleton, and a small amount of an ionic component (hydrophilic component) is introduced into the skeleton. Such an ionomer-type urethane resin is suitable as a water-based adhesive because it is emulsified directly in water without using an emulsifier to form an emulsion. Polyester-based ionomer urethane resins are known per se. For example, JP-A-7-97504 describes an example of a polymer dispersant for dispersing a phenol-based resin in an aqueous medium. In JP-A-2005-70140 and JP-A-2005-208456, a mixture of a polyester ionomer type urethane resin and a compound having a glycidyloxy group is used as an adhesive, and a polarizing film made of a polyvinyl alcohol resin is used as a cycloolefin-based film. The form which bonds a resin film is shown.

  As a method of applying an adhesive to the polarizing film and / or the film (resin film, protective film or optical compensation film) bonded thereto, a generally known method may be used. For example, a casting method, a Meyer bar may be used. Examples thereof include a coating method, a gravure coating method, a comma coater method, a doctor blade method, a die coating method, a dip coating method, and a spraying method. The casting method is a method of spreading and spreading an adhesive on the surface of a film to be coated while moving it in a substantially vertical direction, a substantially horizontal direction, or an oblique direction between the two. After apply | coating an adhesive agent, a polarizing film and the film bonded by this are piled up, and it bonds by a nip roll etc. and bonds a film. Film bonding using nip rolls is, for example, a method in which an adhesive is applied and then pressurized with a roll or the like to spread uniformly, and after applying an adhesive, it is passed between the rolls and pressed. A method of spreading out can be employed. In the former case, it is possible to use metal or rubber as the material of the roll. In the latter case, the plurality of rolls may be made of the same material or different materials.

  The surface of the adhesive layer may be appropriately subjected to surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (flame) treatment, saponification treatment, etc., in order to improve adhesion. Examples of the saponification treatment include a method of immersing in an aqueous alkali solution such as sodium hydroxide or potassium hydroxide.

  After the pasting, the polarizing plate can be obtained by drying and curing the adhesive layer. This drying treatment is performed, for example, by blowing hot air, and the temperature is usually in the range of 40 to 100 ° C, preferably in the range of 60 to 100 ° C. The drying time is usually 20 to 1200 seconds.

  The thickness of the adhesive layer after drying is usually 0.001 to 5 μm, preferably 0.01 to 2 μm, and more preferably 0.01 to 1 μm. When the thickness of the adhesive layer is less than 0.001 μm, the adhesion may be insufficient, and when the thickness of the adhesive layer exceeds 5 μm, the appearance of the polarizing plate may be poor.

  Moreover, after the said drying, you may obtain sufficient adhesive strength by giving a curing | curing for at least half a day at the temperature more than room temperature, Preferably several days or more. The preferable curing temperature is in the range of 30-50 ° C, more preferably 35-45 ° C. When the curing temperature exceeds 50 ° C., so-called “roll tightening” is likely to occur in the roll winding state. The humidity during curing is not particularly limited, and the relative humidity may be in the range of 0 to 70% RH. The curing time is usually 1 to 10 days, preferably 2 to 7 days.

  Moreover, a photocurable adhesive can also be used as the adhesive. As a photocurable adhesive agent, mixtures, such as a photocurable epoxy resin and a photocationic polymerization initiator, are mentioned, for example. When using a photocurable adhesive, a photocurable adhesive is hardened by irradiating an active energy ray. The light source of the active energy ray is not particularly limited, but an active energy ray having a light emission distribution at a wavelength of 400 nm or less is preferable. Specifically, the low-pressure mercury lamp, the medium-pressure mercury lamp, the high-pressure mercury lamp, the ultrahigh-pressure mercury lamp, the chemical lamp, and the black light lamp A microwave excitation mercury lamp, a metal halide lamp and the like are preferable.

The light irradiation intensity to the photocurable adhesive is appropriately determined depending on the composition of the photocurable adhesive and is not particularly limited, but the irradiation intensity in the wavelength region effective for activating the polymerization initiator is 0.1 to 6000 mW. / Cm ² is preferable. When the irradiation intensity is 0.1 mW / cm ² or more, the reaction time does not become too long, and when the irradiation intensity is 6000 mW / cm ² or less, the heat radiated from the light source and the time of curing of the photocurable adhesive There is little risk of yellowing of the epoxy resin or deterioration of the polarizing film due to heat generation. The light irradiation time to the photocurable adhesive is controlled for each photocurable adhesive to be cured and is not particularly limited. However, the integrated light amount expressed as the product of the irradiation intensity and the irradiation time is 10. It is preferably set to be 10000 mJ / m ² . When the cumulative amount of light to the photo-curable adhesive is 10 mJ / m ² or more, a sufficient amount of active species derived from the polymerization initiator can be generated to allow the curing reaction to proceed more reliably, and 10,000 mJ / m. ^{By being 2} or less, the irradiation time does not become too long, and good productivity can be maintained.

  When curing a photocurable adhesive by irradiation with active energy rays, various functions of the polarizing plate such as the degree of polarization of the polarizing film, the transmittance and the hue, and the transparency of the resin film, the protective film and the optical compensation film are reduced. It is preferable to perform the curing under conditions that do not.

  In the polarizing plate of the present invention, the surface of the polarizing film opposite to the side on which the resin film is laminated (on the film when the protective film or the optical compensation film is laminated) has an adhesive layer. It is preferable. As the pressure-sensitive adhesive used for such a pressure-sensitive adhesive layer, a conventionally known appropriate pressure-sensitive adhesive can be used without particular limitation, and examples thereof include an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, and a silicone pressure-sensitive adhesive. Among these, an acrylic pressure-sensitive adhesive is preferably used from the viewpoints of transparency, adhesive strength, reliability, reworkability, and the like. The pressure-sensitive adhesive layer can be provided by a method in which such a pressure-sensitive adhesive is, for example, an organic solvent solution, which is applied on a base film (for example, a polarizing film) by a die coater or a gravure coater, and dried. It can also provide by the method of transcribe | transferring the sheet-like adhesive formed on the plastic film (it is called a separate film) to which the mold release process was given to a base film. Although there is no restriction | limiting in particular also about the thickness of an adhesive layer, Generally it is preferable to exist in the range of 2-40 micrometers.

  An optical functional film may be attached to the surface of the polarizing plate on which the pressure-sensitive adhesive layer is formed via the pressure-sensitive adhesive layer. As an optical functional film, for example, an optical compensation film in which a liquid crystal compound is coated on a substrate surface and oriented; a reflection type that transmits a certain kind of polarized light and reflects polarized light that shows the opposite property Polarizing film; Retardation film made of polycarbonate-based resin; Retardation film made of cyclic polyolefin-based resin; Film with anti-glare function having uneven shape on surface; Film with surface anti-reflection function; Reflecting film having reflection function on surface; And a transflective film having both a reflection function and a transmission function. Commercially available products corresponding to an optical compensation film coated with a liquid crystal compound on the surface of the base material are “WV film” (Fuji Film Co., Ltd.), “NH film” (Shin Nippon Oil Co., Ltd.) And “NR Film” (manufactured by Nippon Oil Corporation). For example, “DBEF” (manufactured by 3M, available from Sumitomo 3M Co., Ltd. in Japan) is a commercially available product corresponding to a reflective polarizing film that transmits certain types of polarized light and reflects polarized light that exhibits the opposite properties. Can be obtained), “APF” (manufactured by 3M, available from Sumitomo 3M Co., Ltd. in Japan), and the like. Moreover, as a commercial item corresponding to the phase difference film which consists of cyclic polyolefin resin, for example, "Arton film" (made by JSR Corporation), "Essina" (made by Sekisui Chemical Co., Ltd.), "Zeonor film" ( (Manufactured by Optes Co., Ltd.).

  The polarizing plate of this invention can be used suitably as a back side polarizing plate arrange | positioned between the liquid crystal cell with which a liquid crystal display device is equipped, and a backlight.

<Liquid crystal panel and liquid crystal display device>
The liquid crystal panel of the present invention comprises a liquid crystal cell and the polarizing plate of the present invention laminated on the liquid crystal cell, and the liquid crystal cell and the polarizing plate have a surface on which a resin film in the polarizing film is laminated, Is bonded via an adhesive layer so that the opposite surface faces the liquid crystal cell (that is, the resin film forms the outer surface of the liquid crystal panel). Such a liquid crystal panel of the present invention is applied to a liquid crystal display device such that the resin film is on the backlight side (so that the polarizing plate of the present invention is disposed between the liquid crystal cell and the backlight). . In the liquid crystal panel of the present invention, a polarizing plate is provided on the front side of the liquid crystal cell (the viewing side when applied to a liquid crystal display device and the side opposite to the side on which the polarizing plate of the present invention is laminated). The polarizing plate provided on the front side of the liquid crystal cell is not particularly limited, and any conventionally known appropriate polarizing plate can be used. For example, the polarizing plate etc. which the glare-proof process, the hard-coat process, and the antireflection process were given are mentioned. Moreover, the polarizing plate by which the polyethylene terephthalate film, the acrylic film, and the polypropylene film were laminated | stacked on the single side | surface of the polarizing film may be sufficient.

  The liquid crystal display device of the present invention includes a liquid crystal panel arranged so that the resin film of the polarizing plate is on the backlight side. Such a liquid crystal display device of the present invention is provided with a liquid crystal panel in which the polarizing plate of the present invention is bonded to the back side of the liquid crystal cell, so that the image has no scratches or unevenness and has excellent image quality and is compatible with thinning. However, it has sufficient mechanical strength, and further, because the resin film of the polarizing plate of the present invention is arranged on the back side of the liquid crystal panel, it can prevent adhesion between the liquid crystal panel and the backlight system, Visibility has been improved. Moreover, damage to other optical members adjacent to the resin film can be prevented.

  In the liquid crystal display device of the present invention, as the configuration other than the liquid crystal panel, an appropriate configuration of a conventionally known liquid crystal display device can be adopted. For example, a backlight, a light diffusion plate, and the liquid crystal panel of the present invention The structure provided in this order, and the structure provided with the backlight, the light diffusing plate, the light diffusing sheet, and the liquid crystal panel of the present invention in this order can be given. In the former case, the liquid crystal panel is arranged so that the resin film of the polarizing plate faces the light diffusion plate, and in the latter case, the liquid crystal panel is arranged so that the resin film of the polarizing plate faces the light diffusion sheet. . Further, another optical member such as a light collecting sheet may be disposed between the backlight and the liquid crystal panel as necessary.

  In the liquid crystal display device of the present invention, when a diffusion film having light diffusibility is used as the resin film, the light diffusibility is imparted to the polarizing plate itself of the present invention used as the back-side polarizing plate. In addition, a part or all of the light diffusion sheet provided on the light diffusion plate can be omitted, which makes it possible to reduce the thickness and weight of the liquid crystal display device. Further, when a resin film other than a diffusion film having light diffusibility (a resin film having a regular uneven shape) is used as the resin film, the light emission direction is adjusted and the brightness is increased by condensing. Therefore, the visibility can be improved and the light collecting sheet can be omitted.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified.

In the following examples, the steel wool hardness (the number of scratches when rubbed with steel wool) on the outer surface of the diffusion film is measured under the following conditions and visually observed.
Steel wool model number: # 0000
Shape of the part (frictional) that contacts the outer surface of the steel wool diffusion film: 1 cm square with 2 cm sides (area 4 cm ² ), steel wool fibers lined up parallel to the sides, and reciprocating in the fiber direction.
Load on steel wool: 250 g / cm ² (1000 g / 4 cm ² ),
Stroke width of steel wool: 5cm (reciprocation 10cm),
Speed during reciprocating friction: 50 reciprocations / min (500 cm / min).

  Further, the pencil hardness of the outer surface of the diffusion film is measured with a load of 500 g using an electric pencil scratch hardness tester (No.553-M, manufactured by Yasuda Seiki Seisakusho Co., Ltd.) in accordance with JIS K 5600-5-4. It was measured.

(Production Example 1: Production of polarizing film)
A polyvinyl alcohol film having a thickness of 75 μm made of polyvinyl alcohol having an average polymerization degree of about 2400 and a saponification degree of 99.9 mol% or more was immersed in pure water at 30 ° C., and the weight ratio of iodine / potassium iodide / water was 0. It was immersed in an aqueous solution of 0.02 / 2/100 at 30 ° C. Then, it was immersed at 56.5 ° C. in an aqueous solution having a potassium iodide / boric acid / water weight ratio of 12/5/100. Subsequently, after washing with pure water at 8 ° C., it was dried at 65 ° C. to obtain a polarizing film in which iodine was adsorbed and oriented on a polyvinyl alcohol film. Stretching was mainly performed in the iodine staining and boric acid treatment steps, and the total stretching ratio was 5.3 times.

(Production Example 2: Production of diffusion film A)
An ultraviolet curable resin composition in which the following components were dissolved in ethyl acetate at a solid concentration of 60% by weight was prepared.

Pentaerythritol triacrylate 60 parts Polyfunctional urethanized acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate) 40 parts Next, 100 parts by weight of the solid content of the ultraviolet curable resin composition is subjected to photopolymerization 5 parts by weight of initiator “Lucirin TPO” (manufactured by BASF, chemical name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide), acrylic organic fine particles (manufactured by Soken Chemical Co., Ltd., average particle size 8 μm) , Refractive index 1.55) 11.25 parts by weight were added to prepare a coating solution. This coating solution is coated on a commercially available polyethylene terephthalate film (thickness 38 μm) so that the cured resin layer has a thickness of 10 μm, dried, and then cured by UV irradiation to cure on the polyethylene terephthalate film. A diffusion film A on which a resin layer was formed was obtained.

  The pencil hardness of the outer surface of the obtained diffusion film A (the surface opposite to the side bonded to the polarizing film and the surface of the cured resin layer in which the diffusing agent was dispersed) was H. Further, the number of scratches when the outer surface of the obtained diffusion film A was rubbed with steel wool under the above conditions was one.

(Production Example 3: Production of diffusion film B)
In the same manner as described in Example 1 of JP-A-2000-75136, a diffusion film B having a fine concavo-convex structure on the surface using a triacetyl cellulose film as a base film was produced. This fine concavo-convex structure is formed by roughening a base film by sandblasting.

  The pencil hardness of the outer surface (fine uneven surface) of the obtained diffusion film B was B. Further, when the outer surface of the obtained diffusion film B was rubbed with steel wool under the above conditions, at least 50 or more scratches were confirmed.

<Example 1>
On one surface of the polarizing film obtained in Production Example 1 above, the diffusion film A obtained in Production Example 2 was applied, and on the other surface of the polarizing film, a triacetyl cellulose film (thickness 80 μm, Konica Minolta Opto Co., Ltd.). Were made using a photocurable adhesive, and the adhesive was cured by irradiation of ultraviolet rays to obtain a polarizing plate. An acrylic pressure-sensitive adhesive layer having a thickness of 25 μm was provided on the outer surface of the triacetyl cellulose film of the polarizing plate.

  The polarizing plate is placed on the back of the liquid crystal cell via the adhesive layer, and a commercially available polarizing plate is placed on the front of the liquid crystal cell to assemble a liquid crystal panel. A liquid crystal display device was manufactured in combination with a light. In this liquid crystal display device, the liquid crystal panel is configured such that the diffusion film A side faces the prism film. When assembling the liquid crystal display device, the liquid crystal panel was slid on the prism film and adjusted in order to accurately determine the position where the liquid crystal panel was superimposed. When the display image of the liquid crystal display device was visually observed, an image having no scratches or unevenness was obtained, and the visibility was good.

<Comparative Example 1>
Instead of the diffusion film A obtained in Production Example 2, a polarizing plate was obtained in the same manner as in Example 1 except that the diffusion film B obtained in Production Example 3 was used, and this was used in the same manner as in Example 1. Thus, a liquid crystal display device was produced. When the display image of the liquid crystal display device was visually observed, only an image showing scratches and unevenness was obtained, and the visibility was poor. After the observation, the liquid crystal panel was taken out from the liquid crystal display device, and the surface (the outer surface of the diffusion film B) was observed. As a result, scratches were observed on the surface.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims (8)

A polarizing film comprising a uniaxially stretched polyvinyl alcohol-based resin film in which iodine or a dichroic dye is adsorbed and oriented, and a resin film laminated on at least one surface of the polarizing film,
When the surface of the resin film opposite to the side facing the polarizing film is rubbed 10 times under the conditions of a load of 250 g / cm ² , a stroke width of 5 cm, and a speed of 50 reciprocations per minute, using steel wool. The number of scratches is 10 or less,
The polarizing plate which is a back side polarizing plate arrange | positioned between the liquid crystal cell with which a liquid crystal display device is provided, and a backlight.   The polarizing plate according to claim 1, wherein the pencil hardness of the surface of the resin film opposite to the side facing the polarizing film is H or less.   The polarizing plate according to claim 1, wherein the resin film is a diffusion film having light diffusibility.   One surface of the said resin film consists of a smooth surface whose 10-point average roughness is less than 0.1 micrometer, and the other surface consists of an uneven surface whose 10-point average roughness is 0.1 micrometer or more. The polarizing plate in any one of.   The polarizing plate in any one of Claims 1-4 provided with the optical compensation film or protective film laminated | stacked on the surface on the opposite side to the surface where the said resin film in the said polarizing film is laminated | stacked. A liquid crystal panel comprising a liquid crystal cell and the polarizing plate according to any one of claims 1 to 5 laminated on the liquid crystal cell,
The said polarizing plate is a liquid crystal panel arrange | positioned so that the surface on the opposite side to the surface where the said resin film is laminated | stacked in the said polarizing film may oppose the said liquid crystal cell. A liquid crystal display device comprising a backlight, a light diffusion plate and the liquid crystal panel according to claim 6 in this order,
The liquid crystal panel is a liquid crystal display device in which the resin film of the polarizing plate is disposed so as to face the light diffusion plate. A liquid crystal display device comprising a backlight, a light diffusion plate, a light diffusion sheet and the liquid crystal panel according to claim 6 in this order,
The liquid crystal panel is a liquid crystal display device in which the resin film of the polarizing plate is disposed so as to face the light diffusion sheet.