JP2012013851A - Set of polarizing plates, liquid crystal panel and liquid crystal display device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a set of polarizing plates which has an outer protective film made thin and difficult to break, and a liquid crystal panel and a liquid crystal display device which include the same.SOLUTION: The set of polarizing plates comprises a first polarizing plate 20 disposed on one surface side of a liquid crystal cell 40 and a second polarizing plate 30 disposed on the other surface side, and the first polarizing plate 20 is obtained by laminating a first polarizing film 21 and a first outer protective film 25 in this order, and the second polarizing plate 30 is obtained by laminating a second polarizing film 31 and a second outer protective film 35 in this order. At least one of the first outer protective film 25 and the second outer protective film 35 is made of a stretched acrylic resin. The acrylic resin preferably comprises an acrylic resin composition where 25 to 45 wt% rubber elastic particles having a number average particle size of 10 to 300 nm are blended in a transparent acrylic resin.

Description

  The present invention relates to a set of polarizing plates, a liquid crystal panel including the same, and a liquid crystal display device, and more particularly to a set of polarizing plates disposed on both sides of a liquid crystal cell, a liquid crystal panel including the same, and a liquid crystal display device.

  A liquid crystal display device has characteristics such as low power consumption, operation at a low voltage, and light weight and thinness. Therefore, the liquid crystal display device is used in various display devices by taking advantage of these characteristics. The liquid crystal display device is composed of many materials such as a liquid crystal cell, a polarizing plate, a retardation film, a condensing sheet, a diffusion film, a light guide plate, and a light reflecting sheet. Therefore, improvements aiming at productivity, weight reduction, brightness improvement, etc. are actively performed by reducing the number of constituent films or reducing the thickness of the film or sheet.

  On the other hand, a liquid crystal display device is required to have a product that can withstand severe durability conditions depending on applications. For example, a liquid crystal display device for a car navigation system may have a high temperature and humidity in a vehicle in which the liquid crystal display device is placed, and the temperature and humidity conditions are severe as compared with a monitor for a normal television or personal computer. For such applications, polarizing plates that are highly durable are also required.

  The polarizing plate usually has a structure in which a transparent protective film is laminated on one side or both sides of a polarizer (polarizing film) made of a polyvinyl alcohol resin to which a dichroic dye is adsorbed and oriented. The polarizer is manufactured by a method in which a polyvinyl alcohol-based resin film is subjected to longitudinal uniaxial stretching and dyeing with a dichroic dye, then treated with boric acid to cause a crosslinking reaction, and then washed with water and dried.

  As the dichroic dye, iodine or a dichroic organic dye is used. A polarizing plate is formed by laminating a protective film on one or both sides of the polarizer thus obtained, and is used by being incorporated in a liquid crystal display device.

  For the protective film, a cellulose acetate-based resin film typified by triacetyl cellulose is often used, and the thickness thereof is usually in the range of about 30 to 120 μm. In addition, an adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin is often used for laminating the protective film.

  However, a polarizing plate in which a protective film made of triacetyl cellulose is laminated on one or both sides of a polarizer to which a dichroic dye is adsorbed and oriented via an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin under wet heat conditions. When used for a long time, there are problems that the polarization performance is deteriorated and the protective film and the polarizer are easily peeled off.

  Therefore, a method has been proposed in which at least one of the protective films is made of a resin other than cellulose acetate.

  For example, in a polarizing plate in which protective films are laminated on both sides of a polarizer, it is known that at least one of the protective films is composed of a thermoplastic norbornene resin having the function of a retardation film at the same time (for example, a patent Reference 1).

  In addition, a protective film made of an amorphous polyolefin-based resin is laminated on one surface of a polarizer made of a polyvinyl alcohol-based resin film on which iodine or a dichroic organic dye is adsorbed and oriented, and on the other surface, a cellulose acetate-based film A polarizing plate in which a protective film made of a resin different from an amorphous polyolefin-based resin such as a resin is laminated is known (for example, see Patent Document 2).

  Furthermore, it is also known that a protective film made of a cycloolefin resin is laminated on a polarizer made of a polyvinyl alcohol resin via an adhesive containing a urethane resin and a polyvinyl alcohol resin (for example, And Patent Document 3).

  In addition, it is also known that a polarizer made of a polyvinyl alcohol resin is laminated with a cycloolefin resin film having specific retardation characteristics to form a polarizing plate (for example, see Patent Document 4).

  However, amorphous polyolefin resins (cycloolefin resins) such as norbornene resins are recently put into practical use and are more expensive than triacetyl cellulose. It was often used as a phase difference film.

  Therefore, it has also been proposed to use an inexpensive resin material for the protective film of the polarizing plate. For example, polyolefin resins and acrylic resins have been studied as resin materials. As the polyolefin-based resin, for example, it is known that a crystalline polyolefin-based resin, particularly a polypropylene-based resin is used as a protective film (see, for example, Patent Document 5).

  However, when a polypropylene resin is used as a protective film for a polarizing plate, the film of triacetyl cellulose or amorphous polyolefin resin is protected on the liquid crystal cell side, particularly in a configuration in which the polypropylene resin film is disposed on the liquid crystal cell side surface. There was a problem that the front contrast was liable to be reduced as compared with the film configuration.

  On the other hand, a protective film made of a (meth) acrylic resin containing a lactone ring is known as an acrylic resin (see, for example, Patent Document 6). By providing such a protective film, it is possible to provide a polarizing plate excellent in durability and display uniformity.

  Furthermore, a polarizing plate protective film obtained by uniaxially or biaxially stretching an acrylic resin within a stretch ratio of 50 to 200% is known (for example, see Patent Document 7). By using such a stretched acrylic resin, an optical film having excellent mechanical strength and heat shrinkability can be obtained.

JP-A-8-43812 JP 2002-174729 A JP 2004-334168 A JP 2007-65452 A JP 2009-75471 A JP 2009-122663 A JP 2008-216586 A

  The protective film made of the acrylic resin described above has a problem that it is inferior in flexibility and easily broken.

  An object of the present invention is to provide a polarizing plate set on both surfaces of a liquid crystal cell, in which an outer protective film is not easily broken and the entire thickness can be reduced. Further, another object of the present invention is to provide a liquid crystal panel and a liquid crystal display device using such a set of thin polarizing plates which are not easily broken.

  According to the set of polarizing plates of the present invention, the above problem is a liquid crystal comprising a first polarizing plate disposed on one surface side of a liquid crystal cell and a second polarizing plate disposed on the other surface side. A set of polarizing plates for display, wherein the first polarizing plate is formed by laminating a first polarizing film made of a polyvinyl alcohol-based resin and a first outer protective film made of a transparent resin in this order. The second polarizing plate is formed by laminating a second polarizing film made of polyvinyl alcohol resin and a second outer protective film made of a transparent resin, and the first outer protective film and the first polarizing film are laminated. At least one of the two outer protective films is solved by being made of a stretched acrylic resin.

  In this case, the acrylic resin is uniaxially stretched in the machine flow direction (MD) or the direction (TD) orthogonal to the machine flow direction, or orthogonal to the machine flow direction (MD) and the machine flow direction. Biaxial stretching is preferably performed simultaneously or sequentially in the direction (TD).

  The first polarizing film and the first outer protective film, and the second polarizing film and the second outer protective film are each composed of a resin composition containing an epoxy compound that is cured by active energy rays. It is preferable that they are bonded by an adhesive.

  The acrylic resin is preferably composed of an acrylic resin composition in which 25 to 45% by weight of rubber elastic particles having a number average particle diameter of 10 to 300 nm are blended in a transparent acrylic resin.

  Further, the first polarizing plate has a first inner protective film laminated on the surface of the first polarizing film opposite to the side on which the first outer protective film is laminated. The first inner protective film has an internal haze value of 0.5% or less and an external haze value of 5% or less, an in-plane retardation value at a wavelength of 590 nm of 10 nm or less, and a thickness at a wavelength of 590 nm. The absolute value of the direction retardation value is preferably 10 nm or less.

  The second polarizing plate has a second inner protective film laminated on a surface of the second polarizing film opposite to the side on which the second outer protective film is laminated. The second inner protective film has an internal haze value of 0.5% or less and an external haze value of 5% or less, an in-plane retardation value at a wavelength of 590 nm of 10 nm or less, and a thickness at a wavelength of 590 nm. The absolute value of the direction retardation value is preferably 10 nm or less.

  Moreover, according to the liquid crystal panel of this invention, the said subject consists of a liquid crystal cell and a pair of polarizing plate arrange | positioned on the both surfaces, and a pair of said polarizing plate is a polarizing plate in any one of said It is a set, and is solved by being characterized in that the first outer protective film and the second outer protective film are laminated on the side farthest from the liquid crystal cell.

  In addition, according to the liquid crystal display device of the present invention, the above object includes a backlight, a light diffusing plate, and the liquid crystal panel described above, and the backlight, the light diffusing plate, the first polarizing plate, and the liquid crystal It is solved by arranging the cell and the second polarizing plate in this order.

  According to the set of polarizing plates of the present invention, the strength of the outer protective film made of an acrylic resin is improved by the stretching treatment, so that it has a property that it is less likely to break than a conventional protective film. Furthermore, since the outer protective film is thinned by the stretching treatment, it is possible to reduce the thickness of the entire polarizing plate. Furthermore, since the acrylic resin is less likely to cause a phase difference due to the stretching process than other resins, a rainbow unevenness is hardly generated, and a polarizing plate having excellent optical characteristics can be obtained.

  In addition, according to the present invention, it is possible to provide a liquid crystal panel or a liquid crystal display device provided with a set of polarizing plates that are not easily broken and thin and hardly cause rainbow unevenness.

It is a cross-sectional schematic diagram of the set of the polarizing plate which concerns on 1st Embodiment. It is a cross-sectional schematic diagram of the liquid crystal panel and liquid crystal display device which used the set of the polarizing plate which concerns on 1st Embodiment. It is a cross-sectional schematic diagram of the set of the polarizing plate which concerns on other embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, this invention is not limited by the member, arrangement | positioning, etc. which are demonstrated below, These members etc. can be suitably changed in accordance with the meaning of this invention.

<First Embodiment>
A set of polarizing plates, a liquid crystal panel, and a liquid crystal display device according to the first embodiment of the present invention will be described below. FIG. 1: has shown the cross-sectional schematic diagram of the set of the polarizing plate of this invention. As shown in this figure, the set of polarizing plates of the present invention is composed of a first polarizing plate 20 and a second polarizing plate 30. As shown in FIG. 2 described later, these are used as components of the liquid crystal panel 2 and the liquid crystal display device 1. The liquid crystal panel 2 can be manufactured by laminating the first polarizing plate 20 and the second polarizing plate 30 on both surfaces of the liquid crystal cell 40. In the present embodiment, the first polarizing plate 20 and the second polarizing plate 30 are polarizing plates for forming the viewing side polarizing plate and the back side polarizing plate of the liquid crystal panel 2, respectively. Here, “back-side polarizing plate” means a polarizing plate located on the backlight 10 side when the liquid crystal panel 2 is mounted on the liquid crystal display device 1, and “viewing-side polarizing plate” means the liquid crystal panel 2. Means a polarizing plate located on the viewing side (opposite side of the backlight 10) when mounted on the liquid crystal display device 1. Hereinafter, the first polarizing plate 20 will be described in detail.

[First polarizing plate]
As shown in FIG. 1, the first polarizing plate 20 is formed by laminating a first inner protective film 23, a first polarizing film 21, and a first outer protective film 25 in this order.

  The first polarizing plate 20 is used by being bonded to the liquid crystal cell 40, and in order from the side close to the liquid crystal cell 40, the first inner protective film 23, the first polarizing film 21, and the first outer protective film 25. Is arranged to be positioned. A hard coat layer 26 may be provided on the outer side of the first outer protective film 25. Furthermore, the laminated film 24 composed of the first outer protective film 25 and the hard coat layer 26 may constitute the antiglare film 24.

Hereinafter, each component will be described in detail with a preferred example.
(First polarizing film)
The first polarizing film 21 is obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol-based resin film so as to obtain predetermined polarizing characteristics. As the dichroic dye, iodine or a dichroic organic dye is used. Specific examples of the first polarizing film 21 include an iodine polarizing film obtained by adsorbing and orienting iodine on a polyvinyl alcohol resin film, a dye polarizing film obtained by adsorbing and orienting a dichroic organic dye on a polyvinyl alcohol resin film, and the like. Is mentioned.

  The polyvinyl alcohol resin can be obtained by saponifying a polyvinyl acetate resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like can be used.

  The first polarizing plate 20 is usually a humidity adjusting step for adjusting the water content of the polyvinyl alcohol-based resin film, a step for uniaxially stretching the polyvinyl alcohol-based resin film, and a dichroic dye for dyeing the polyvinyl alcohol-based resin film. A step of adsorbing a chromatic dye, a step of treating a polyvinyl alcohol-based resin film adsorbed and oriented with a dichroic dye with an aqueous boric acid solution, a washing step of washing off the aqueous boric acid solution, and a dichroic dye subjected to these steps It is manufactured through a process of bonding a protective film to a uniaxially stretched polyvinyl alcohol resin film in which is adsorbed and oriented.

  Uniaxial stretching may be performed before dyeing, may be performed during dyeing, or may be performed during boric acid treatment after dyeing. You may uniaxially stretch in these several steps. For uniaxial stretching, rolls having different peripheral speeds may be uniaxially stretched or uniaxially stretched 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 4 to 8 times. The thickness of the 1st polarizing film 21 which consists of a polyvinyl alcohol-type film by which extending | stretching and dyeing | staining was made can be 1-50 micrometers, for example.

(First inner protective film)
The first inner protective film 23 has a function of protecting the surface of the first polarizing film 21. As the 1st inner side protective film 23, it can select suitably according to the characteristic requested | required of the applied liquid crystal cell 40 or the liquid crystal display device 1, and can be used. In particular, when the liquid crystal cell 40 using IPS mode or blue phase liquid crystal described later is used, the first inner protective film 23 is not stretched and is substantially positioned in the plane or in the thickness direction. A non-oriented protective film having no phase difference is preferred.

  Since the non-oriented film has no phase difference, it does not have a function of widening the viewing angle of the liquid crystal display device 1 like a biaxially stretched film, but does not need to be stretched like a biaxially stretched film. Therefore, the manufacturing cost is low. Therefore, compared with the case where a biaxially stretched film is used, the manufacturing cost of the liquid crystal display device 1 can be lowered.

  The first inner protective film 23 preferably has a Gurley method bending resistance measured in accordance with JIS L 1096 of 350 mgf or less, more preferably 200 mgf or less, and even more preferably 150 mgf or less. Even more preferred. Thus, since the rigidity of the 1st polarizing plate 20 obtained is reduced by using the 1st inner side protective film 23 with small bending resistance, the handling property at the time of bonding to the liquid crystal cell 40 is carried out. Can be improved.

  The resin material constituting the inner protective film 23 is not particularly limited. As such a resin material, for example, a known material such as an olefin resin, a cellulose resin, a vinyl resin, or a styrene resin can be appropriately selected and used. Among these, an olefin resin is particularly preferable from the viewpoint of the optical characteristics of the liquid crystal display device 1.

((Olefin resin))
Olefin resin is a general term for polyethylene resin, polypropylene resin, cycloolefin resin, and the like, and the set of polarizing plates of the present invention is applied to a liquid crystal panel for a large-sized liquid crystal television, particularly a liquid crystal panel 2 having an IPS mode liquid crystal cell 40 When used, the first inner protective film 23 is preferably a non-oriented polypropylene resin film from the viewpoint of optical properties and durability.

Here, the reason why a polypropylene resin is preferable as the first inner protective film 23 will be described. Since the polypropylene-based resin has a small photoelastic coefficient of around 2 × 10 ⁻¹³ cm ² / dyne, when used in the liquid crystal display device 1, light leakage in the display area is small and moisture permeability is low. Surprisingly, the adhesion of the polypropylene resin film to the polarizing film is good if not as much as that of the triacetyl cellulose film, and when using various known adhesives, the polypropylene resin film is sufficient. It was found to adhere to the first polarizing film 21 made of polyvinyl alcohol resin with strength. For these reasons, a polypropylene resin is preferably used as the first inner protective film 23 disposed on one surface of the first polarizing film 21.

The polypropylene resin can be produced by a method of homopolymerizing propylene using a known polymerization catalyst or a method of copolymerizing propylene and another copolymerizable comonomer. Examples of known polymerization catalysts include the following.
(1) Ti—Mg-based catalyst comprising a solid catalyst component containing magnesium, titanium and halogen as essential components,
(2) a catalyst system in which a solid catalyst component containing magnesium, titanium and halogen as essential components is combined with an organoaluminum compound and, if necessary, a third component such as an electron donating compound,
(3) Metallocene catalysts.

  Among these catalyst systems, in the production of a polypropylene resin used as the first inner protective film 23 in the present invention, an organic aluminum compound, an electron donating compound, and a solid catalyst component containing magnesium, titanium and halogen as essential components A combination of these is most commonly used. More specifically, the organoaluminum compound is preferably triethylaluminum, triisobutylaluminum, a mixture of triethylaluminum and diethylaluminum chloride, tetraethyldialumoxane, etc., and the electron donating compound is preferably cyclohexylethyldimethoxysilane. Tert-butylpropyldimethoxysilane, tert-butylethyldimethoxysilane, dicyclopentyldimethoxysilane, and the like.

  On the other hand, examples of the solid catalyst component containing magnesium, titanium and halogen as essential components include the catalysts described in JP-A-61-218606, JP-A-61-287904, JP-A-7-216017, and the like. Examples of the metallocene catalyst include the catalyst systems described in Japanese Patent No. 2587251, Japanese Patent No. 2627669, Japanese Patent No. 2668732, and the like.

  Polypropylene resins include, for example, solution polymerization using an inert solvent typified by a hydrocarbon compound such as hexane, heptane, octane, decane, cyclohexane, methylcyclohexane, benzene, toluene, and xylene, and a liquid monomer as a solvent. It can be produced by a bulk polymerization method or a gas phase polymerization method in which a gaseous monomer is polymerized as it is. Polymerization by these methods may be carried out batchwise or continuously.

  The stereoregularity of the polypropylene resin may be any of isotactic, syndiotactic, and atactic. In the present invention, a syndiotactic or isotactic polypropylene resin is preferably used from the viewpoint of heat resistance.

  The polypropylene resin used in the present invention can be composed of a propylene homopolymer, and contains a small amount of a comonomer mainly composed of propylene and copolymerizable therewith, for example, 20% by weight or less, preferably 10% by weight or less. Copolymerized with When a copolymer is used, the amount of comonomer is preferably 1% by weight or more.

  The comonomer copolymerized with propylene may be, for example, ethylene or an α-olefin having 4 to 20 carbon atoms. Specific examples of the α-olefin in this case include the following.

1-butene, 2-methyl-1-propene (above C ₄ ); 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene (above C ₅ ); 1-hexene, 2-ethyl- 1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene ₆ ); 1-heptene, 2-methyl-1-hexene, 2,3-dimethyl-1-pentene, 2-ethyl-1-pentene, 2-methyl-3-ethyl-1-butene (above C ₇ ); 1-octene, 5-methyl-1-heptene, 2-ethyl-1-hexene, 3,3-dimethyl-1-hexene, 2-methyl-3-ethyl-1-pentene, 2,3,4-trimethyl- 1-pentene, 2-propyl-1-pentene, , 3-diethyl-1-butene (or _C 8); 1-nonene _(C 9); 1-decene _(C 10); 1-undecene _(C 11); 1-dodecene _(C 12); 1-tridecene ( C ₁₃ ); 1-tetradecene (C ₁₄ ); 1-pentadecene (C ₁₅ ); 1-hexadecene (C ₁₆ ); 1-heptadecene (C ₁₇ ); 1-octadecene (C ₁₈ ); 1-nonadecene (C ₁₉₎ )Such.

  Preferred among the α-olefins are α-olefins having 4 to 12 carbon atoms, specifically 1-butene, 2-methyl-1-propene; 1-pentene, 2-methyl-1- Butene, 3-methyl-1-butene; 1-hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4- Methyl-1-pentene, 3,3-dimethyl-1-butene; 1-heptene, 2-methyl-1-hexene, 2,3-dimethyl-1-pentene, 2-ethyl-1-pentene, 2-methyl- 3-ethyl-1-butene; 1-octene, 5-methyl-1-heptene, 2-ethyl-1-hexene, 3,3-dimethyl-1-hexene, 2-methyl-3-ethyl-1-pentene, 2,3,4-trimethyl-1-pen And ten-, 2-propyl-1-pentene, 2,3-diethyl-1-butene; 1-nonene; 1-decene; 1-undecene; 1-dodecene, and the like. From the viewpoint of copolymerizability, 1-butene, 1-pentene, 1-hexene and 1-octene are preferable, and 1-butene and 1-hexene are more preferable.

The copolymer may be a random copolymer or a block copolymer.
Preferred copolymers include propylene / ethylene copolymers and propylene / 1-butene copolymers. In the propylene / ethylene copolymer and the propylene / 1-butene copolymer, the ethylene unit content and the 1-butene unit content are, for example, 616 of “Polymer Analysis Handbook” (published by Kinokuniya, 1995). Infrared (IR) spectrum measurement can be performed by the method described on the page.

  From the viewpoint of increasing the transparency and processability as a protective film to be bonded to the polarizing film, it is preferable to use propylene as a main component and a random copolymer with any unsaturated hydrocarbon. Of these, a copolymer with ethylene is preferred. When making it into a copolymer, it is advantageous that unsaturated hydrocarbons other than propylene have a copolymerization ratio of about 1 to 10% by weight, and a more preferable copolymerization ratio is 3 to 7% by weight. By setting the unit of unsaturated hydrocarbons other than propylene to 1% by weight or more, there is a tendency that an effect of improving processability and transparency appears. However, if the ratio exceeds 10% by weight, the melting point of the resin tends to decrease and the heat resistance tends to deteriorate, which is not preferable. In addition, when setting it as the copolymer of two or more types of comonomers, and a polypropylene, it is preferable that the total content of the unit derived from all the comonomers contained in the copolymer is the said range.

  The polypropylene resin used as the first inner protective film 23 of the present invention has a melt flow rate (MFR) measured at a temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K 7210 of 0.1 to 200 g / It is preferably in the range of 10 minutes, particularly 0.5 to 50 g / 10 minutes. By using a polypropylene resin having an MFR in this range, a uniform film can be obtained without imposing a large load on the extruder.

  The polypropylene resin may contain a known additive as long as the effects of the present invention are not impaired. Examples of the additive include an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a nucleating agent, an antifogging agent, and an antiblocking agent. Antioxidants include, for example, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, hindered amine light stabilizers, etc., and, for example, a phenolic antioxidant mechanism in one molecule A composite antioxidant having a unit having a phosphorus-based antioxidant mechanism can also be used. Examples of the UV absorber include UV absorbers such as 2-hydroxybenzophenone and hydroxyphenylbenzotriazole, and benzoate UV blockers. The antistatic agent may be polymer type, oligomer type or monomer type. Examples of the lubricant include higher fatty acid amides such as erucic acid amide and oleic acid amide, higher fatty acids such as stearic acid, and salts thereof. Examples of the nucleating agent include sorbitol nucleating agents, organophosphate nucleating agents, and polymer nucleating agents such as polyvinylcycloalkane. As the anti-blocking agent, fine particles having a spherical shape or a shape close thereto can be used regardless of inorganic type or organic type. A plurality of these additives may be used in combination.

((Raw film of polypropylene resin))
The polypropylene resin can be formed into an original film by any method. This raw film is transparent and has substantially no in-plane retardation. For example, a polypropylene system having substantially no in-plane retardation by extrusion molding from molten resin, solvent casting method in which a resin dissolved in an organic solvent is cast on a flat plate, and the solvent is removed to form a film. A resin raw film can be obtained.

  A method for producing a raw film by extrusion will be described in detail. The polypropylene resin is melted and kneaded by rotation of a screw in an extruder and extruded from a T die into a sheet. The temperature of the molten sheet to be extruded is about 180 to 300 ° C. If the temperature of the molten sheet at this time is lower than 180 ° C., the spreadability is not sufficient, the thickness of the resulting film becomes non-uniform, and there is a possibility that the film has phase difference unevenness. Further, when the temperature exceeds 300 ° C., the resin is easily deteriorated or decomposed, and bubbles may be generated in the sheet or carbides may be contained.

  The extruder may be a single screw extruder or a twin screw extruder. For example, in the case of a single screw extruder, L / D, which is the ratio of the screw length L to the diameter D, is about 24 to 36, the screw groove space volume in the resin supply unit, and the screw groove space volume in the resin metering unit The compression ratio, which is the ratio (the former / the latter), is about 1.5 to 4, and a screw such as a full flight type, a barrier type, and a type having a Maddock type kneading portion can be used. From the viewpoint of suppressing deterioration and decomposition of the polypropylene resin and uniformly melting and kneading, it is necessary to use a barrier type screw having an L / D of 28 to 36 and a compression ratio of 2.5 to 3.5. preferable. Moreover, in order to suppress deterioration and decomposition | disassembly of polypropylene resin as much as possible, it is preferable to make the inside of an extruder into nitrogen atmosphere or a vacuum. Furthermore, in order to remove the volatile gas generated by the deterioration or decomposition of the polypropylene resin, it is also preferable to provide an orifice of 1 mmφ to 5 mmφ at the tip of the extruder to increase the resin pressure at the tip of the extruder. Increasing the resin pressure at the tip of the extruder at the orifice means increasing the back pressure at the tip, thereby improving the stability of extrusion. The diameter of the orifice to be used is more preferably 2 mmφ or more and 4 mmφ or less.

The T-die used for extrusion preferably has no fine steps or scratches on the surface of the resin flow path, and its lip is plated or coated with a material having a low coefficient of friction with the molten polypropylene resin. Further, a sharp edge shape with a lip tip polished to 0.3 mmφ or less is preferable. Examples of the material having a small friction coefficient include tungsten carbide type and fluorine type special plating. By using such a T-die, it is possible to suppress the generation of eyes and simultaneously suppress the die line, so that a resin film having excellent appearance uniformity can be obtained. In the T-die, the manifold has a coat hanger shape and preferably satisfies the following condition (1) or (2), and more preferably satisfies the condition (3) or (4).
When the lip width of the T die is less than 1500 mm: length in the thickness direction of the T die> 180 mm (1)
When the lip width of the T die is 1500 mm or more: length in the thickness direction of the T die> 220 mm (2)
When the lip width of the T die is less than 1500 mm: Length in the height direction of the T die> 250 mm (3)
When the lip width of the T die is 1500 mm or more: Length in the height direction of the T die> 280 mm (4)
By using a T die that satisfies these conditions, the flow of the molten polypropylene resin inside the T die can be adjusted, and the lip portion can be extruded while suppressing thickness unevenness, so that the thickness is increased. An original film having excellent accuracy and a more uniform retardation can be obtained.

  From the viewpoint of suppressing the extrusion fluctuation of the polypropylene resin, it is preferable to attach a gear pump via an adapter between the extruder and the T die. In addition, it is preferable to attach a leaf disk filter to remove foreign substances in the polypropylene resin.

  The molten sheet extruded from the T-die is between a metal cooling roll (also referred to as a chill roll or a casting roll) and a touch roll including an elastic body that presses and rotates in the circumferential direction of the metal cooling roll. A desired film can be obtained by clamping and solidifying by cooling. In this case, the touch roll may be one in which an elastic body such as rubber is directly on the surface, or may be one in which the surface of the elastic body roll is covered with an outer cylinder made of a metal sleeve. When using a touch roll in which the surface of the elastic roll is covered with an outer cylinder made of a metal sleeve, the molten sheet of polypropylene resin is directly sandwiched between the metal cooling roll and the touch roll for cooling. On the other hand, in the case of using a touch roll whose surface is an elastic body, a biaxially stretched film of a thermoplastic resin can be interposed between the molten sheet of polypropylene resin and the touch roll for sandwiching.

  When the molten sheet of polypropylene resin is sandwiched between the cooling roll and the touch roll as described above and cooled and solidified, both the cooling roll and the touch roll have their surface temperatures lowered, and the molten sheet is rapidly cooled. It is necessary to let Specifically, the surface temperature of both rolls is adjusted to a range of 0 ° C. or higher and 30 ° C. or lower. When these surface temperatures exceed 30 ° C., it takes time to cool and solidify the molten sheet, so that the crystal component in the polypropylene resin grows, and the resulting film is inferior in transparency. The surface temperature of the roll is preferably less than 30 ° C, more preferably less than 25 ° C. On the other hand, when the surface temperature of the roll is less than 0 ° C., condensation occurs on the surface of the metallic cooling roll, and water droplets adhere to the surface, which tends to deteriorate the appearance of the film.

  Since the surface state of the metal cooling roll used is transferred to the surface of the polypropylene resin film, there is a possibility that the thickness accuracy of the resulting polypropylene resin film may be lowered if the surface is uneven. . Therefore, it is preferable that the surface of the metal cooling roll is in a mirror surface state as much as possible. Specifically, the roughness of the surface of the metal cooling roll is preferably 0.4 S or less, more preferably 0.05 S to 0.2 S, expressed as a standard sequence of the maximum height.

  The touch roll that forms the nip portion with the metal cooling roll has a surface hardness of 65 to 80 as a value measured by a spring type hardness test (A type) defined in JIS K 6301. It is more preferable, and it is more preferable that it is 70-80. By using a rubber roll having such a surface hardness, it becomes easy to maintain a uniform linear pressure applied to the molten sheet, and a bank of the molten sheet (resin pool) is provided between the metal cooling roll and the touch roll. ) Can be easily formed into a film.

  The pressure (linear pressure) when sandwiching the molten sheet is determined by the pressure for pressing the touch roll against the metal cooling roll. The linear pressure is preferably 50 N / cm or more and 300 N / cm or less, and more preferably 100 N / cm or more and 250 N / cm or less. By setting the linear pressure within the above range, it becomes easy to produce a polypropylene resin film while maintaining a constant linear pressure without forming a bank.

  When a biaxially stretched film of a thermoplastic resin is sandwiched between a metallic cooling roll and a touch roll together with a molten sheet of polypropylene resin, the thermoplastic resin constituting the biaxially stretched film is strong with the polypropylene resin. Any resin may be used as long as it is not heat-sealed, and specific examples include polyester, polyamide, polyvinyl chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and polyacrylonitrile. Among these, polyesters that have little dimensional change due to humidity, heat, and the like are most preferable. In this case, the thickness of the biaxially stretched film is usually about 5 to 50 μm, preferably 10 to 30 μm.

  In this method, the distance (air gap) from the lip of the T die to the pressure between the metal cooling roll and the touch roll is preferably 200 mm or less, and more preferably 160 mm or less. The molten sheet extruded from the T-die is stretched from the lip to the roll, and orientation tends to occur. By shortening the air gap as described above, a film having a smaller orientation can be obtained. The lower limit of the air gap is determined by the diameter of the metal cooling roll to be used, the diameter of the touch roll, and the tip shape of the lip to be used, and is usually 50 mm or more.

  The processing speed for producing a polypropylene resin raw film by this method is determined by the time required for cooling and solidifying the molten sheet. When the diameter of the metal cooling roll to be used is increased, the distance at which the molten sheet is in contact with the cooling roll becomes longer, so that production at a higher speed is possible. Specifically, when a 600 mmφ metal cooling roll is used, the processing speed is about 5 to 20 m / min at the maximum.

  The molten sheet sandwiched between the metal cooling roll and the touch roll is cooled and solidified by contact with the roll. And after slitting an edge part as needed, it is wound up by a winder and becomes a film. Under the present circumstances, in order to protect the surface until it uses a film, you may wind up in the state which bonded the surface protection film which consists of another thermoplastic resin to the single side | surface or both surfaces. When a molten sheet of polypropylene resin is sandwiched between a metal cooling roll and a touch roll together with a biaxially stretched film made of a thermoplastic resin, the biaxially stretched film is used as one surface protective film. You can also.

(First outer protective film)
The first outer protective film 25 is a resin film made of a transparent acrylic resin. The first outer protective film 25 has an internal haze value of 0.5% or less and an external haze value of 5% or less, an in-plane retardation value (R ₀ ) at a wavelength of 590 nm of 10 nm or less, and a wavelength The absolute value of the retardation value (R _th ) in the thickness direction at 590 nm is 10 nm or less. The acrylic resin of the first outer protective film 25 of the present embodiment is composed of an acrylic resin composition containing 25 to 45% by weight of rubber elastic body particles having a number average particle diameter of 10 to 300 nm. The blending ratio of the body particles is the weight ratio of the rubber elastic particles to the weight of the whole acrylic resin composition including the rubber elastic particles.

  The monomer composition of the acrylic resin is preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 90% by weight based on a total of 100% by weight of all monomers. This is a polymer mainly composed of alkyl methacrylate, wherein the alkyl methacrylate is 99% by weight or less. In addition, it may be a homopolymer of alkyl methacrylate, or a copolymer of 50% by weight or more of alkyl methacrylate and 50% by weight or less of a monomer other than alkyl methacrylate. As the alkyl methacrylate, those having 1 to 4 carbon atoms of the alkyl group are usually used, and among them, methyl methacrylate is preferably used.

  The monomer other than alkyl methacrylate may be a monofunctional monomer having one polymerizable carbon-carbon double bond in the molecule, or two or more polymerizable carbons in the molecule. -A polyfunctional monomer having a carbon double bond may be used, but a monofunctional monomer is preferably used here, and examples thereof include alkyl acrylates such as methyl acrylate and ethyl acrylate, Examples thereof include styrene monomers such as styrene and alkylstyrene, and unsaturated nitriles such as acrylonitrile and methacrylonitrile. When using alkyl acrylate as a copolymerization component, the carbon number is 1-8 normally.

  In the present invention, the acrylic resin preferably does not have a glutarimide derivative, a glutaric anhydride derivative, a lactone ring structure, or the like. A glutarimide derivative, a glutaric anhydride derivative, and an acrylic resin having a lactone ring structure may not provide sufficient mechanical strength and heat-and-moisture resistance as a protective film.

  The rubber elastic body particles contained in the first outer protective film 25 are particles containing a rubber elastic body, and may be particles composed only of the rubber elastic body, or a multilayer structure having a rubber elastic body layer. The particles may also be Examples of rubber elastic bodies include olefin-based elastic polymers, diene-based elastic polymers, styrene-diene-based elastic copolymers, and acrylic-based elastic polymers. Among these, acrylic elastic polymers are preferably used from the viewpoint of the surface hardness, light resistance, and transparency of the protective film.

  The acrylic elastic polymer may be a polymer mainly composed of alkyl acrylate, may be a homopolymer of alkyl acrylate, or may be a single polymer other than alkyl acrylate of 50% by weight or more and alkyl acrylate. A copolymer with 50% by weight or less of the monomer may be used. As the alkyl acrylate, those having 4 to 8 carbon atoms in the alkyl group are usually used. Examples of monomers other than alkyl acrylate include alkyl methacrylates such as methyl methacrylate and ethyl methacrylate, styrene monomers such as styrene and alkyl styrene, acrylonitrile and methacrylonitrile. Monofunctional monomers such as unsaturated nitriles, alkenyl esters of unsaturated carboxylic acids such as allyl (meth) acrylate and methallyl (meth) acrylate, dialkenyl esters of dibasic acids such as diallyl maleate, And polyfunctional monomers such as unsaturated carboxylic acid diesters of glycols such as alkylene glycol di (meth) acrylate.

  The rubber elastic particle containing the acrylic elastic polymer is preferably a multi-layered particle having an acrylic elastic polymer layer, and a polymer mainly composed of alkyl methacrylate outside the acrylic elastic polymer. It may be a two-layer structure having the above-mentioned layer, or a three-layer structure having a polymer layer mainly composed of alkyl methacrylate inside the acrylic elastic polymer. In addition, the example of the monomer composition of the polymer mainly composed of alkyl methacrylate constituting the layer formed on the outside or inside of the acrylic elastic polymer is the alkyl methacrylate mentioned above as an example of the acrylic resin. It is the same as that of the example of the monomer composition of the polymer which has mainly. Such acrylic rubber elastic particles having a multilayer structure can be produced, for example, by the method described in Japanese Patent Publication No. 55-27576.

  In the present invention, rubber elastic particles having a number average particle diameter of 10 to 300 nm of the rubber elastic body contained therein are used. Thereby, when laminating | stacking on the 1st polarizing film 21 using an adhesive agent, the 1st outer side protective film 25 which cannot peel easily from an adhesive bond layer can be obtained. The number average particle diameter of the rubber elastic body is preferably 50 nm or more, and preferably 250 nm or less.

  In the case of rubber elastic particles in which the outermost layer is a polymer mainly composed of methyl methacrylate and the acrylic elastic polymer is encapsulated therein, the rubber elastic particles are mixed with the base acrylic resin. Since the outermost layer of the resin is mixed with the base acrylic resin, the rubber elastic particles are excluded from the outermost layer when the acrylic elastic polymer is dyed with ruthenium oxide in the cross section and observed with an electron microscope. It is observed as particles in a wet state. Specifically, in the case of using rubber elastic particles having a two-layer structure in which the inner layer is an acrylic elastic polymer and the outer layer is a polymer mainly composed of methyl methacrylate, the inner layer is an acrylic elastic polymer. The portion is dyed and observed as particles having a single layer structure. Further, the rubber elastic particles having a three-layer structure in which the innermost layer is a polymer mainly composed of methyl methacrylate, the intermediate layer is an acrylic elastic polymer, and the outermost layer is a polymer mainly composed of methyl methacrylate. When is used, the center part of the innermost layer particle is not dyed, and only the acrylic elastic polymer part of the intermediate layer is dyed and observed as a two-layered particle. In this specification, the number average particle diameter of the rubber elastic particles is, as described above, when the rubber elastic particles are mixed with the base resin and the cross section is dyed with ruthenium oxide. It is the number average value of the diameter of the part to be done.

  The acrylic resin composition forming the first outer protective film 25 has a structure in which 25 to 45% by weight of rubber elastic body particles having a number average particle diameter of 10 to 300 nm are blended in a transparent acrylic resin. is there.

  The acrylic resin composition is produced, for example, by obtaining rubber elastic particles and then polymerizing a monomer as a raw material for the acrylic resin in the presence thereof to produce a base acrylic resin. Alternatively, the rubber elastic particles and the acrylic resin may be obtained and then mixed by melt kneading or the like.

  For the acrylic resin composition, if necessary, colorants such as pigments and dyes, fluorescent brighteners, dispersants, heat stabilizers, light stabilizers, infrared absorbers, ultraviolet absorbers, antistatic agents. Further, a compounding agent such as an antioxidant, a lubricant or a solvent may be contained.

  The ultraviolet absorber is added to improve durability by absorbing ultraviolet rays of 400 nm or less. As the ultraviolet absorber, known ones such as a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, and an acrylonitrile ultraviolet absorber can be used. Among them, 2,2'-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy-3 ' -Tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,4-di-tert-butyl-6- (5-chlorobenzotriazol-2-yl) phenol, 2,2'-dihydroxy- 4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone and the like are preferably used. Among these, 2,2′-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol) is particularly preferable. The concentration of the ultraviolet absorber may be selected in such a range that the transmittance of the first outer protective film 25 at a wavelength of 370 nm or less is preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less. it can. Examples of the method of containing the ultraviolet absorber include a method of previously blending the ultraviolet absorber into the acrylic resin; a method of supplying it directly at the time of melt extrusion molding, and any method may be employed.

  Infrared absorbers include nitroso compounds, metal complexes thereof, cyanine compounds, squarylium compounds, thiol nickel complex compounds, phthalocyanine compounds, naphthalocyanine compounds, triallylmethane compounds, imonium compounds, diimonium compounds, Infrared absorption of naphthoquinone compounds, anthraquinone compounds, amino compounds, aminium salt compounds, carbon black, indium tin oxide, antimony tin oxide, metal oxides belonging to Group 4A, 5A or 6A, carbides, borides, etc. An agent etc. can be mentioned. These infrared absorbers are preferably selected so as to be able to absorb the entire infrared ray (light having a wavelength in the range of about 800 nm to 1100 nm), and two or more types may be used in combination. The amount of the infrared absorber can be appropriately adjusted so that, for example, the light transmittance of the first outer protective film 25 at a wavelength of 800 nm or more is 10% or less.

  The acrylic resin composition forming the first outer protective film 25 preferably has a glass transition temperature Tg in the range of 80 to 120 ° C. Further, the acrylic resin composition has a high surface hardness when formed into a film, specifically, a pencil hardness (load of 500 g, conforming to JIS K5600-5-4) exceeding 2H. preferable.

  The acrylic resin composition preferably has a flexural modulus (JIS K7171) of 1500 MPa or less from the viewpoint of flexibility of the first outer protective film 25. The flexural modulus is more preferably 1300 MPa or less, and still more preferably 1200 MPa or less. This flexural modulus varies depending on the type and amount of acrylic resin and rubber elastic particles in the acrylic resin composition. For example, as the content of rubber elastic particles increases, the flexural modulus generally decreases. Become. In addition, the use of a copolymer of an alkyl methacrylate and an alkyl acrylate as an acrylic resin generally has a lower flexural modulus than using an alkyl methacrylate homopolymer. In addition, the elastic elastic polymer particles having the two-layer structure are generally used as the elastic rubber particles, rather than the acrylic elastic polymer particles having the two-layer structure. In general, the flexural modulus is smaller when the acrylic elastic polymer particles having a layer structure are used. Further, in the rubber elastic body particles, as the average particle diameter of the rubber elastic body is smaller or the amount of the rubber elastic body is larger, the bending elastic modulus is generally smaller. Therefore, it is preferable to adjust the kind and amount of the acrylic resin and the rubber elastic body particles within the predetermined range so that the flexural modulus is 1500 MPa or less.

  When the first outer protective film 25 has a multilayer structure, the layer that can be present in addition to the layer of the acrylic resin composition is not particularly limited in its composition, for example, an acrylic resin that does not contain rubber elastic particles. Alternatively, it may be a layer of the composition, or a layer made of an acrylic resin composition in which the content of the rubber elastic body particles and the average particle diameter of the rubber elastic body in the rubber elastic body particles are outside the above regulations. May be. Typically, it has a two-layer or three-layer structure, for example, a two-layer structure composed of a layer of the above-mentioned acrylic resin composition / an acrylic resin not containing rubber elastic particles or a layer of the composition. Alternatively, it may be a three-layer structure composed of the acrylic resin composition layer / the acrylic resin not containing the rubber elastic particles or the composition layer / the acrylic resin composition layer. The first outer protective film 25 having a multi-layer configuration may be a surface of the acrylic resin composition layer used as a bonding surface with the first polarizing film 21.

  Further, when the first outer protective film 25 has a multilayer structure, the content of each layer of the elastic rubber particles and the compounding agent may be different from each other. For example, a layer containing an ultraviolet absorber and / or an infrared absorber and a layer not containing an ultraviolet absorber and / or an infrared absorber may be laminated with this layer interposed therebetween. In addition, the content of the ultraviolet absorber in the acrylic resin composition layer is higher than the content of the ultraviolet absorber in the acrylic resin or the composition layer containing no rubber elastic particles. Specifically, the former is preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, and the latter is preferably 0 to 1% by weight, more preferably 0 to 0.5% by weight. Thus, ultraviolet rays can be efficiently blocked without deteriorating the color tone of the polarizing plate, and a decrease in the degree of polarization during long-term use can be prevented.

  The first outer protective film 25 of the present invention is characterized in that it is made of a stretched acrylic resin film. By performing the stretching treatment in this way, the film thickness is reduced and the strength of the first outer protective film 25 is also improved. Such a first outer protective film 25 can be obtained by first forming the acrylic resin composition and then stretching the obtained unstretched film (raw film).

  The acrylic resin is formed into an unstretched film by any method. This unstretched film is preferably transparent and substantially free of in-plane retardation. Examples of the film forming method include an extrusion method in which a molten resin is extruded to form a film, and a solvent cast method in which a solvent dissolved in an organic solvent is cast on a flat plate and then the solvent is removed to form a film. Etc. can be adopted.

  As a specific example of the extrusion molding method, for example, there is a method of forming a film in a state where an acrylic resin composition is sandwiched between two metal rolls. In this case, the metal roll is preferably a mirror roll. Thereby, the unstretched film excellent in surface smoothness can be obtained. In addition, when obtaining the thing of a multilayer structure as the protective films 12 and 13, what is necessary is just to film-form the said acrylic resin composition after multilayer extrusion with another acrylic resin composition. The thickness of the unstretched film thus obtained is preferably 30 to 200 μm, more preferably 50 to 100 μm.

  Subsequently, the obtained unstretched film is stretched. By this stretching treatment, the thin first outer protective film 25 having high mechanical strength can be obtained. Examples of the stretching treatment include uniaxial stretching and biaxial stretching. Examples of the stretching direction include a machine flow direction (MD) of an unstretched film, a direction orthogonal to the machine flow direction (TD), and a direction oblique to the machine flow direction (MD). Biaxial stretching may be simultaneous biaxial stretching in which stretching is performed simultaneously in two stretching directions, or sequential biaxial stretching in which stretching is performed in a predetermined direction and then stretching in another direction.

  Such a stretching process can be performed by, for example, stretching in the longitudinal direction (machine flow direction: MD) using two or more pairs of nip rolls with increased peripheral speed on the outlet side, or holding both ends of an unstretched film with a chuck. Or by spreading it in a direction (TD) perpendicular to the machine flow direction.

The draw ratio by the drawing treatment is preferably 50 to 300%, particularly 100 to 250%, more preferably 150 to 200%. When the draw ratio is less than 50%, the mechanical strength of the protective films 12 and 13 is not improved so much, which is not preferable. On the other hand, if the draw ratio exceeds 300%, the film thickness becomes too thin and, on the contrary, it becomes easy to break or the handling property is lowered, which is not preferable. In addition, the draw ratio here is calculated | required using the following numerical formula.
Formula: Stretch ratio (%) = 100 × {(Length after stretching) − (Length before stretching)} / (Length before stretching)

  Since the first outer protective film 25 obtained in this way has been subjected to stretching treatment, it has higher mechanical strength than an unstretched film and is not easily broken.

  Moreover, the protective films 12 and 13 are thin compared with an unstretched film. Specifically, the film thickness of the protective films 12 and 13 after stretching is 0.7 to 0.25 times the thickness of the unstretched film when the film thickness is 1.

  Next, the haze value of the first outer protective film 25 will be described. The haze value is the ratio of diffuse transmitted light to the total transmitted light when the film is irradiated with visible light. It is recognized that the smaller the haze value is, the better the film is. Moreover, an internal haze value shows the value which deducted the haze value (external haze value) resulting from the surface shape of a film from the haze value of a film.

  As for the haze value of the 1st outer side protective film 25, it is preferable that an internal haze value is 0.5% or less, and it is preferable that an external haze value is 5% or less. When the internal haze value exceeds 0.5% and the external haze value exceeds 5%, the light transmitted through the film is scattered, and the display characteristics may be deteriorated when bonded to the liquid crystal cell 40.

The retardation value of the first outer protective film 25 will be described. The refractive index of in-plane slow axis direction n _x of the _film, the refractive index n _y in-plane fast axis direction (direction orthogonal with the slow axis and the _plane), the refractive index in the thickness direction n _z, thickness Where d is the in-plane retardation value (R ₀ ) and the thickness direction retardation value (R _th ) are defined by the following equations (I) and (II), respectively.
_{R 0 = (n x -n y} ) × d (I)
R _th = [(n _x + _ny ) / 2−n _z ] × d (II)

The first outer protective film 25 preferably has an in-plane retardation value (R ₀ ) at a wavelength of 590 nm of 10 nm or less, and more preferably 5 nm or less. The absolute value of the thickness direction retardation value (R _th ) at a wavelength of 590 nm is preferably 30 nm or less. When the in-plane retardation value (R ₀ ) of the first outer protective film 25 is larger than 10 nm and the absolute value of the retardation value (R _th ) in the thickness direction is larger than 30 nm, the leakage light is colored in an oblique direction. A phenomenon occurs and display characteristics deteriorate.

  The angle formed between the MD (machine direction, the longitudinal direction of the film obtained in a long shape) of the first outer protective film 25 and the optical axis is preferably ± 5 ° or less, more preferably ± 3 °. It is as follows. When the above angle is larger than ± 5 °, light leakage at the time of black display becomes large, and the reduction in contrast ratio becomes remarkable.

Further, the transmittance parameter value calculated from the in-plane retardation value and the angle between the MD and the optical axis is preferably 0.03 or less, more preferably 0.007 or less, and still more preferably. Is 0.001 or less. When this value is larger than 0.03, the light leakage at the time of black display becomes remarkable, and the reduction of the contrast ratio becomes remarkable. The transmittance parameter here is defined by the following equation, where θ represents the angle formed by the MD of the first outer protective film 25 and the optical axis, and R ₀ is an in-plane retardation value at a wavelength of 590 nm. Represents.
(Transmittance ^{parameter) = sin 2 2θ × sin 2} (π × R 0/590)

  The first outer protective film 25 may be subjected to a hard coat treatment from the viewpoint of preventing scratches. Moreover, you may perform an anti-glare process from a viewpoint of the reflection on a liquid crystal display by external light.

(Hard coat layer)
A hard coat layer 26 may be provided on the outer side of the first outer protective film 25. The hard coat layer 26 is a layer having a function of increasing the surface hardness of the first outer protective film 25 and is “H” or more in a pencil hardness test (a test plate is a glass plate) shown in JIS K5600-5-4. It is preferable to show the hardness. The laminated film 24 composed of the first outer film 25 and the hard coat layer 26 provided with such a hard coat layer 26 preferably has a pencil hardness of 4H or higher. The material for forming the hard coat layer 26 (hard coat material) is preferably a material that is cured by heat or light. For example, organic silicone, melamine, epoxy, acrylic, urethane acrylate, or other organic materials are used. Hard coat materials; inorganic hard coat materials such as silicon dioxide; Among these, urethane acrylate-based and polyfunctional acrylate-based hard coat materials are preferable from the viewpoint of good adhesion and excellent productivity.

  The hard coat layer 26 is made of various fillers for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage, and improving heat resistance, antistatic properties, antiglare properties, and the like as desired. Can be contained. Alternatively, the docoat layer 26 can contain additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a leveling agent, and an antifoaming agent.

(Anti-glare film)
The laminated film 24 composed of the first outer protective film 25 and the hard coat layer 26 may be the antiglare film 24. The anti-glare film 24 is composed of a first outer protective film 25 and a hard coat layer 26 having a fine surface irregularity laminated on the surface thereof.

  The haze value of the antiglare film 24 is 0.1% or more and 45% or less, preferably 5% or more and 40% or less. When the haze value is larger than 45%, the reflection of external light can be reduced, but the black display screen is reduced. On the other hand, when the haze value is less than 0.1%, sufficient anti-glare performance cannot be obtained, and external light is reflected on the screen and cannot be practically used. Here, the haze value is measured by a method based on JIS K 7136.

  The hard coat layer 26 having the fine surface irregularities described above contains a method of forming a coating film containing organic fine particles or inorganic fine particles on the surface of the first outer protective film 25, or contains organic fine particles or inorganic fine particles. Or after forming the coating film which does not contain, it can manufacture by the method (for example, embossing method etc.) pressed against the roll which provided the uneven | corrugated shape etc., It is not limited to these. Examples of the method for forming the coating film include a method of applying a coating solution containing a binder component made of a curable resin composition and organic fine particles or inorganic fine particles to the surface of the first outer protective film 25. can do.

  Typical examples of inorganic fine particles include silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate, and the like. As the organic fine particles, resin particles such as crosslinked polyacrylic acid particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles, and polyimide particles can be used.

  The binder component for dispersing the inorganic fine particles or the organic fine particles is preferably selected from materials having high hardness (hard coat). As the binder component, a photocurable resin, a thermosetting resin, an electron beam curable resin, and the like can be used, and a photocurable resin is preferably used from the viewpoint of productivity, hardness, and the like. A commercially available resin can be used as the photocurable resin. For example, one or more polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, and “Irgacure 907”, “Irgacure 184” (above, manufactured by Ciba Specialty Chemicals), “ A mixture with a photopolymerization initiator such as “Lucillin (registered trademark) TPO” (manufactured by BASF) can be used as a photocurable resin. For example, when a photocurable resin is used, after dispersing inorganic fine particles or organic fine particles in the photocurable resin, the resin composition is applied on the first outer protective film 25 and irradiated with light. Thus, the hard coat layer 26 in which inorganic fine particles or organic fine particles are dispersed in a hard coat resin made of a binder resin can be formed.

  In detail, examples of the photocurable resin include a mixture of urethane acrylate, polyol (meth) acrylate, (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups, and a photopolymerization initiator. it can.

  The urethane acrylate is preferably prepared using (meth) acrylic acid and / or (meth) acrylic ester, polyol, and diisocyanate. For example, preparing urethane acrylate by preparing hydroxy (meth) acrylate having at least one hydroxyl group from (meth) acrylic acid and / or (meth) acrylic acid ester and polyol, and reacting it with diisocyanate. it can. These (meth) acrylic acid and / or (meth) acrylic acid ester, polyol, and diisocyanate may be used singly or in combination of two or more. Moreover, you may add various additives according to the objective.

  Examples of the (meth) acrylic acid ester include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and butyl (meth) acrylate; Examples include cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate.

  The above polyol is a compound having at least two hydroxyl groups, such as ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol. 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decane glycol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1, 5-pentanediol, hydroxypivalic acid neopentyl glycol ester, cyclohexane dimethylol, 1,4-cyclohexane diol, spiro glycol, tricyclodecane methylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene glycol Side addition bisphenol A, trimethylolethane, trimethylolpropane dimethylol propane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythritol, can be exemplified dipentaerythritol, tripentaerythritol, glucose ethers.

  As said diisocyanate, various aromatic, aliphatic, or alicyclic diisocyanates can be used, for example. Specific examples include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4-diphenyl diisocyanate. Xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, and hydrogenated products thereof.

  Specific examples of the polyol (meth) acrylate include pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6- Hexanediol (meth) acrylate is mentioned. These components may be used alone or in combination. Furthermore, you may add various additives as needed. The polyol (meth) acrylate preferably comprises pentaerythritol triacrylate and pentaerythritol tetraacrylate. These may be a copolymer or a mixture.

  Examples of the (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups include, for example, a (meth) acrylic polymer having a 2,3-dihydroxypropyl group, a 2-hydroxyethyl group, and a 2,3-dihydroxypropyl group. (Meth) acrylic polymer which has group is mentioned.

  As the photopolymerization initiator, 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, benzoinpropyl ether, benzyldimethyl ketal, List N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, and other thioxanthates. Can do.

  A solvent is added to the above mixture as necessary. Although it does not restrict | limit especially as a solvent, For example, ethyl acetate, butyl acetate, and these mixed solvents can be mentioned.

  Moreover, said mixture may contain a leveling agent, for example, can mention a fluorine type or a silicone type leveling agent. Examples of the silicone leveling agent include reactive silicone, polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane. Preferred are reactive silicone and siloxane leveling agents. By using a reactive silicone leveling agent, the surface of the hard coat layer 26 is provided with slipperiness, and excellent scratch resistance can be maintained for a long period of time. In addition, when a siloxane leveling agent is used, film formability can be improved.

Examples of the leveling agent for reactive silicone include those having a siloxane bond, an acrylate group, and a hydroxyl group. As a specific example,
(A) (dimethylsiloxane): (3-acryloyl-2-hydroxypropoxypropylsiloxane): (2-acryloyl-3-hydroxypropoxypropylsiloxane) = 0.8: 0.16: 0.04 (molar ratio) Copolymer,
(B) (dimethylsiloxane) :( hydroxypropylsiloxane) :( 6-isocyanatohexylisocyanuric acid) :( aliphatic polyester) = 6.3: 1.0: 2.2: 1.0 (molar ratio) Polymer,
(C) (Dimethylsiloxane): (Methyl polyethylene glycol propyl ether siloxane having an acrylate terminal): (Methyl polyethylene glycol propyl ether siloxane having a hydroxyl group at the terminal) = 0.88: 0.07: 0.05 (molar ratio) And the like.

  As described above, by using the acrylic binder component (binder resin) as exemplified, the adhesion with the first outer protective film 25 is improved, the mechanical strength is further improved, and the surface is more scratched. An antiglare film 24 that can be effectively prevented can be obtained.

  In the case of forming the hard coat layer 26 having the fine unevenness by the embossing method, the shape of the die was formed on the first outer protective film 25 using the mold having the fine unevenness. What is necessary is just to transfer to the hard-coat layer 26. The transfer to the mold-shaped hard coat layer 26 is preferably carried out by embossing, and as the embossing, a UV embossing method using an ultraviolet curable resin which is a kind of a photocurable resin is preferable. In addition, when forming fine surface uneven | corrugated shape by the embossing method, the hard-coat layer 26 may contain the inorganic or organic microparticle, and does not need to contain it.

  In the UV embossing method, an ultraviolet curable resin layer is formed on the surface of the first outer protective film 25, and the ultraviolet curable resin layer is cured while being pressed against the uneven surface of the mold. Transferred to the ultraviolet curable resin layer. Specifically, the first outer protective film 25 is coated with an ultraviolet curable resin on the first outer protective film 25 and the coated ultraviolet curable resin is in close contact with the uneven surface of the mold. The shape of the mold is obtained by irradiating ultraviolet rays from the side to cure the ultraviolet curable resin, and then peeling the first outer protective film 25 on which the cured ultraviolet curable resin layer is formed from the mold. Is transferred to an ultraviolet curable resin. The kind in particular of ultraviolet curable resin is not restrict | limited, For example, the above-mentioned thing can be used. Further, instead of the ultraviolet curable resin, a visible light curable resin that can be cured with visible light having a wavelength longer than that of ultraviolet light may be used by appropriately selecting a photoinitiator.

  The thickness of the hard coat layer 26 is not particularly limited, but is 2 μm or more and 30 μm or less, and more preferably 3 μm or more and 30 μm or less. When the thickness of the hard coat layer 26 is less than 2 μm, sufficient hardness cannot be obtained, and the surface tends to be easily damaged. As a result, the antiglare film 24 tends to curl and the productivity tends to decrease.

  As described above, the antiglare film 24 is preferably provided with haze by the hard coat layer 26, but with the formation of the hard coat layer 26, inorganic or organic fine particles are dispersed in the first outer protective film 25. You may give haze by making it. Further, the antiglare film 24 may have a configuration in which the hard coat layer 26 is not provided and inorganic or organic fine particles are dispersed in the first outer protective film 25. In these cases, the above-mentioned inorganic or organic fine particles can be used. Further, the thickness of the first outer protective film 25 in which inorganic or organic fine particles are dispersed is preferably about 20 to 200 μm, more preferably about 20 to 120 μm, as described above.

  The antiglare film 24 may be subjected to surface treatment such as antistatic treatment in addition to the above-described antiglare treatment (haze imparting treatment), and a coating layer made of a liquid crystalline compound or a high molecular weight compound thereof. It may be formed. However, the antistatic function may be imparted to other portions of the polarizing plate such as an adhesive layer in addition to the surface treatment of the first outer protective film 25.

  The first protective film 25 may be subjected to surface treatment such as anti-glare treatment in addition to anti-glare treatment (haze imparting treatment), and a coating layer made of a liquid crystalline compound or a high molecular weight compound thereof is formed. May be. However, you may provide an antistatic function to other parts of polarizing plates, such as an adhesive layer and an adhesive bond layer, instead of the 1st protective film 25 or with this.

(Bonding of polarizing film and protective film)
Next, the bonding method of the 1st polarizing film 21 and the 1st inner side protective film 23 and the 1st polarizing film 21 and the 1st outer side protective film 25 is demonstrated. An adhesive is preferably used for bonding the first polarizing film 21 and the inner protective film 23, and the first polarizing film 21 and the outer protective film 25. As the adhesive, an adhesive having an epoxy resin, urethane resin, cyanoacrylate resin, acrylamide resin, or the like as an adhesive component can be used. One of the adhesives preferably used in the present invention is a solventless adhesive. Solventless adhesives do not contain a significant amount of solvent, and are curable compounds (monomers or oligomers) that are reactively cured by heating or irradiation with active energy rays (for example, ultraviolet rays, visible light, electron beams, X-rays, etc.) ), And an adhesive layer is formed by curing of the curable compound, and typically includes a curable compound that is reactively cured by heating or irradiation of active energy rays, and a polymerization initiator. Among the solventless adhesives, those that are cured by cationic polymerization are preferable from the viewpoint of reactivity. Particularly, the solventless epoxy adhesive having an epoxy compound as a curable compound includes a polarizing film and an acrylic type. Since it is excellent in the adhesiveness with a resin film, and the adhesiveness with a protective film which consists of resin films other than a polarizing film and acrylic resin, it is more preferable.

  The epoxy compound, which is a curable compound contained in the solventless epoxy adhesive, is not particularly limited, but is preferably one that is cured by cationic polymerization, and particularly from the viewpoint of weather resistance, refractive index, and the like. It is more preferable to use an epoxy compound that does not contain an aromatic ring. Examples of such epoxy compounds that do not contain an aromatic ring in the molecule include hydrides of aromatic epoxy compounds, alicyclic epoxy compounds, and aliphatic epoxy compounds. In addition, the epoxy compound that is a curable compound usually has two or more epoxy groups in the molecule.

  First, the hydride of an aromatic epoxy compound will be described. The hydride of an aromatic epoxy compound is a nuclear water obtained by selectively subjecting an aromatic polyhydroxy compound, which is a raw material of an aromatic epoxy compound, to a hydrogen ring reaction under pressure in the presence of a catalyst. The additive polyhydroxy compound can be obtained by glycidyl etherification. Examples of aromatic epoxy compounds include bisphenol-type epoxy resins such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and diglycidyl ether of bisphenol S; phenol novolac epoxy resins, cresol novolac epoxy resins, hydroxybenzaldehyde Examples include novolak-type epoxy resins such as phenol novolac epoxy resins; glycidyl ethers of tetrahydroxyphenylmethane, glycidyl ethers of tetrahydroxybenzophenone, and polyfunctional epoxy resins such as epoxidized polyvinylphenol. Aromatic polyhydroxy compounds typified by these raw materials, bisphenols, are hydrogenated as described above, and epichlorohydrin is reacted with the hydroxyl groups to obtain hydrides of aromatic epoxy compounds. . Especially, it is preferable to use the glycidyl ether of hydrogenated bisphenol A as a hydride of an aromatic epoxy compound.

Next, the alicyclic epoxy compound will be described. An alicyclic epoxy compound means an epoxy compound having one or more epoxy groups bonded to an alicyclic ring, and “having one or more epoxy groups bonded to an alicyclic ring” is represented by the following formula: Means having the structure shown. In formula, m is an integer of 2-5.

Therefore, the alicyclic epoxy compound is a compound having at least one structure represented by the above formula and having a total of two or more epoxy groups in the molecule. More specifically, a compound in which a group in a form in which one or a plurality of hydrogen atoms in (CH ₂ ) _m in the above formula are removed is bonded to another chemical structure can be an alicyclic epoxy compound. One or more hydrogen atoms in (CH ₂ ) _m may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group. Among such alicyclic epoxy compounds, an epoxy compound having an epoxycyclopentane ring (m = 3 in the above formula) or an epoxycyclohexane ring (m = 4 in the above formula) has high adhesion strength. It is more preferably used because an excellent adhesive can be obtained. Although the structure of the alicyclic epoxy compound preferably used in the present invention is specifically illustrated below, it is not limited to these compounds.

  3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate, ethylenebis (3,4-epoxycyclohexanecarboxy Rate), bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, diethylene glycol bis (3,4-epoxycyclohexylmethyl ether), ethylene glycol bis (3 4-epoxycyclohexyl methyl ether), 2,3,14,15-diepoxy-7,11,18,21-tetraoxatrispiro- [5.2.2.5.2.2] henicosane (this compound is 3, 4 -Epoxycyclohexane spiro-2 ', 6'-dioxane spiro-3 ", 5" -dioxane spiro-3 "", 4 ""-a compound that can also be named epoxycyclohexane), 3- (3 4-epoxycyclohexyl) -8,9-epoxy-1,5-dioxaspiro [5.5] undecane, 4-vinylcyclohexene dioxide, bis-2,3-epoxycyclopentyl ether, dicyclopentadiene dioxide, and the like.

  Examples of the aliphatic epoxy compound include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof. More specifically, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, propylene Polyethers of polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide or propylene oxide) to aliphatic polyhydric alcohols such as glycol diglycidyl ether, ethylene glycol, propylene glycol, and glycerin Examples thereof include glycidyl ether.

  In this invention, an epoxy compound may be used individually by 1 type, or may use 2 or more types together.

  The epoxy equivalent of the epoxy compound contained in the solventless epoxy adhesive is usually in the range of 30 to 3,000 g / equivalent, preferably 50 to 1,500 g / equivalent. When the epoxy equivalent is less than 30 g / equivalent, the flexibility of the protective film after curing may be lowered, or the adhesive strength may be reduced. On the other hand, if the epoxy equivalent exceeds 3,000 g / equivalent, the compatibility with other components contained in the epoxy adhesive may be lowered.

  The solventless epoxy adhesive preferably contains a cationic polymerization initiator in order to cationically polymerize the epoxy compound. The cationic polymerization initiator generates a cationic species or a Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, electron beams, or heating, and initiates an epoxy group polymerization reaction. In the present invention, any type of cationic polymerization initiator may be used. However, it is preferable from the viewpoint of workability that the potential is imparted. In the following, a cationic polymerization initiator that generates a cationic species or a Lewis acid upon irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams and initiates a polymerization reaction of an epoxy group is a photocationic polymerization initiator. Also called.

  The use of a cationic photopolymerization initiator allows the adhesive component to be cured at room temperature, reducing the need to take into account the heat resistance of the polarizing film or distortion due to expansion. Can be formed. In addition, when a cationic photopolymerization initiator is used, it acts catalytically by light, so that it is excellent in storage stability and workability even when mixed with an epoxy adhesive.

  Although it does not specifically limit as a photocationic polymerization initiator, For example, aromatic diazonium salt, aromatic iodonium salt, onium salts, such as an aromatic sulfonium salt, an iron- allene complex, etc. can be mentioned. These cationic photopolymerization initiators may be used alone or in combination of two or more. Among these, aromatic sulfonium salts are particularly preferably used because they have ultraviolet absorption characteristics even in a wavelength region of 300 nm or more, and can provide a cured product having excellent curability and good mechanical strength and adhesive strength. It is done.

  These photocationic polymerization initiators can be easily obtained as commercial products, for example, “Kayarad (registered trademark) PCI-220” and “Kayarad (registered trademark) PCI-620” under trade names. (Manufactured by Nippon Kayaku Co., Ltd.), "UVI-6990" (manufactured by Union Carbide), "ADEKA (registered trademark) Optmer SP-150", "ADEKA (registered trademark) Optmer SP-170" (above, (Made by ADEKA Corporation), “CI-5102”, “CIT-1370”, “CIT-1682”, “CIP-1866S”, “CIP-2048S”, “CIP-2064S” (above, Nippon Soda Co., Ltd.) Manufactured), "DPI-101", "DPI-102", "DPI-103", "DPI-105", "MPI-103", "MPI-105" “BBI-101”, “BBI-102”, “BBI-103”, “BBI-105”, “TPS-101”, “TPS-102”, “TPS-103”, “TPS-105”, “MDS” -103 "," MDS-105 "," DTS-102 "," DTS-103 "(manufactured by Midori Chemical Co., Ltd.)," PI-2074 "(manufactured by Rhodia) and the like.

  The compounding quantity of a photocationic polymerization initiator is 0.5-20 weight part normally with respect to 100 weight part of epoxy compounds, Preferably it is 1 weight part or more, Preferably it is 15 weight part or less.

  The solventless epoxy adhesive may further contain a photosensitizer as necessary together with the photocationic polymerization initiator. By using a photosensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the cured product can be improved. Examples of the photosensitizer include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreductive dyes. When mix | blending a photosensitizer, the quantity is about 0.1-20 weight part with respect to 100 weight part of epoxy compounds.

  In addition, as a thermal cationic polymerization initiator that generates a cationic species or a Lewis acid by heating and initiates a polymerization reaction of an epoxy group, for example, benzylsulfonium salt, thiophenium salt, thiolanium salt, benzylammonium salt, pyridinium salt, hydrazinium Examples thereof include salts, carboxylic acid esters, sulfonic acid esters, and amine imides. These thermal cationic polymerization initiators can also be easily obtained as commercial products. For example, all of them are trade names such as “ADEKA (registered trademark) Opton CP77”, “ADEKA (registered trademark) Opton CP66” (above, (Manufactured by ADEKA Corporation), “CI-2439”, “CI-2624” (manufactured by Nippon Soda Co., Ltd.), “Sun Aid (registered trademark) SI-60L”, “Sun Aid (registered trademark) SI-80L” , “Sun-Aid (registered trademark) SI-100L” (manufactured by Sanshin Chemical Industry Co., Ltd.). These thermal cationic polymerization initiators may be used alone or in admixture of two or more. It is also preferable to use a photocationic polymerization initiator and a thermal cationic polymerization initiator in combination.

  The solventless epoxy adhesive may further contain a compound that promotes cationic polymerization, such as oxetanes and polyols.

  In the case of using a solventless epoxy adhesive, the first polarizing film 21 and the protective films 23 and 25 are bonded to the protective film 23 and 25 and / or the first polarizing film 21. It can be performed by applying to the surface and bonding them together. There is no particular limitation on the method of applying the solvent-free epoxy adhesive to the first polarizing film 21 and / or the protective films 23, 25. For example, doctor blade, wire bar, die coater, comma coater, gravure Various coating methods such as a coater can be used. Moreover, since each coating method has an optimum viscosity range, the viscosity may be adjusted using a small amount of solvent. The solvent used for this purpose is not particularly limited as long as it can dissolve the epoxy adhesive well without degrading the optical performance of the polarizing film. For example, hydrocarbons typified by toluene, typified by ethyl acetate, and the like. Organic solvents such as esters can be used.

  After the protective films 23 and 25 are bonded to the first polarizing film 21 through an adhesive layer made of an uncured epoxy adhesive, the adhesive is applied by irradiating active energy rays or heating. The agent layer is cured, and the protective films 23 and 25 are fixed on the first polarizing film 21. In the case of curing by irradiation with active energy rays, ultraviolet rays are preferably used. Specific examples of the ultraviolet light source include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a black light lamp, and a metal halide lamp. The irradiation intensity and irradiation amount of active energy rays such as ultraviolet rays are appropriately selected so as to sufficiently activate the cationic polymerization initiator and not adversely affect the cured adhesive layer, polarizing film, and protective film. In addition, when cured by heating, it can be heated by a generally known method, and the temperature and time at that time can sufficiently activate the cationic polymerization initiator, and the cured adhesive layer or It is appropriately selected so as not to adversely affect the polarizing film and the protective film.

  The thickness of the adhesive layer made of the epoxy adhesive after curing obtained as described above is usually 0.1 to 50 μm, preferably 1 μm or more. Moreover, it is more preferable that it exists in the range of 1-20 micrometers, and also 2-10 micrometers.

  The solventless epoxy adhesive is bonded to a protective film made of an acrylic resin film and a polarizing film, or bonded to a protective film made of a resin film other than an acrylic resin and a polarizing film, or these It can use preferably for both bonding.

  Moreover, as another preferable adhesive agent which can be used in the present invention, an aqueous adhesive agent, that is, an adhesive component dissolved in water, or a dispersion thereof in water can be exemplified. When a water-based adhesive is used, the thickness of the adhesive layer can be further reduced. Examples of the water-based adhesive include an adhesive component containing a water-soluble crosslinkable epoxy resin or a hydrophilic urethane-based resin.

  As a water-soluble crosslinkable epoxy resin, for example, a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine and a polyamide polyamine obtained by a reaction of a dicarboxylic acid such as adipic acid are reacted with epichlorohydrin. Mention may be made of the polyamide epoxy resin obtained. Examples of such commercially available polyamide epoxy resins include “Smiles (registered trademark) Resin 650” and “Smiles (registered trademark) Resin 675” (both are trade names) sold by Sumika Chemtex Co., Ltd. is there.

  When a water-soluble crosslinkable epoxy resin is used as the adhesive component, it is preferable to mix other water-soluble resins such as a polyvinyl alcohol-based resin in order to further improve coatability and adhesiveness. Polyvinyl alcohol resins are modified such as partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, as well as carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol. Polyvinyl alcohol resin may be used. Among these, a saponified product of a copolymer of vinyl acetate and unsaturated carboxylic acid or a salt thereof, that is, carboxyl group-modified polyvinyl alcohol is preferably used. Here, the “carboxyl group” is a concept including —COOH and a salt thereof.

  Examples of suitable commercially available carboxyl group-modified polyvinyl alcohol include, for example, “Kuraraypoval KL-506”, “Kuraraypoval KL-318”, “Kuraraypoval KL-118” sold by Kuraray Co., Ltd. “GOHSENAL (registered trademark) T-330” and “GOHSENAL (registered trademark) T-350” sold by Nippon Synthetic Chemical Industry Co., Ltd., and “DR-0415” sold by Denki Kagaku Kogyo Co., Ltd. ”,“ AF-17 ”,“ AT-17 ”,“ AP-17 ”and the like sold by Nippon Vinegar Poval Co., Ltd., respectively.

  An adhesive containing a water-soluble crosslinkable epoxy resin can be prepared as an adhesive solution by dissolving the above epoxy resin and other water-soluble resin such as a polyvinyl alcohol resin added as necessary in water. In this case, it is preferable that the water-soluble crosslinkable epoxy resin has a concentration in the range of about 0.2 to 2 parts by weight with respect to 100 parts by weight of water. Moreover, when mix | blending polyvinyl alcohol-type resin, it is preferable that the quantity shall be about 1-10 weight part with respect to 100 weight part of water, Furthermore, it is about 1-5 weight part.

  On the other hand, when a water-based adhesive containing a urethane resin is used, examples of suitable urethane resins include ionomer-type urethane resins, particularly polyester-based ionomer-type urethane resins. Here, the ionomer type is obtained by introducing a small amount of an ionic component (hydrophilic component) into the urethane resin constituting the skeleton. The polyester ionomer type urethane resin is a urethane resin having a polyester skeleton, into which a small amount of an ionic component (hydrophilic component) is introduced. 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. Examples of commercially available polyester ionomer-type urethane resins include “Hydran (registered trademark) AP-20” and “Hydran (registered trademark) APX-101H” sold by DIC Corporation, both of which are emulsions. It can be obtained in the form of

  When an ionomer-type urethane resin is used as an adhesive component, it is preferable to further blend an isocyanate-based crosslinking agent. The isocyanate-based crosslinking agent is a compound having at least two isocyanato groups (—NCO) in the molecule. Examples thereof include 2,4-tolylene diisocyanate, phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1, In addition to polyisocyanate monomers such as 6-hexamethylene diisocyanate and isophorone diisocyanate, adducts in which a plurality of these molecules are added to a polyhydric alcohol such as trimethylolpropane, and three molecules of diisocyanate are each of the isocyanate groups at one end. There are trifunctional isocyanurate forms in which isocyanurate rings are formed at the part, and polyisocyanate modified forms such as burettes formed by hydration and decarboxylation of the three diisocyanate molecules at the respective one-end isocyanato groups. . Examples of commercially available isocyanate crosslinking agents that can be suitably used include “Hydran (registered trademark) Assister C-1” sold by DIC Corporation.

  When an aqueous adhesive containing an ionomer type urethane resin is used, the concentration of the urethane resin is about 10 to 70% by weight, more preferably 20% by weight or more, and 50% by weight or less from the viewpoint of viscosity and adhesiveness. Thus, those dissolved or dispersed in water are preferred. When the isocyanate crosslinking agent is blended, the blending amount is appropriately selected so that the isocyanate crosslinking agent is about 5 to 100 parts by weight with respect to 100 parts by weight of the urethane resin.

  In the case of using the aqueous adhesive, the adhesive between the first polarizing film 21 and the protective films 23 and 25 is applied to the adhesive surface of the protective films 23 and 25 and / or the first polarizing film 21. And it can carry out by bonding both together. More specifically, a water-based adhesive is uniformly applied to the first polarizing film 21 and / or the protective films 23 and 25 by, for example, a coating method such as a doctor blade, a wire bar, a die coater, a comma coater, or a gravure coater. Examples of the method include a method in which the other film is stacked on the coated surface, bonded with a roll, and dried. Drying can be performed at a temperature of about 60 to 100 ° C., for example. In order to further improve the adhesiveness, it is preferable to cure for about 1 to 10 days after drying at a temperature slightly higher than room temperature, for example, a temperature of about 30 to 50 ° C.

  The water-based adhesive, like the solventless epoxy adhesive, is bonded to a protective film made of an acrylic resin film and a polarizing film, or a protective film made of a resin film other than an acrylic resin and polarized light. It can use preferably for pasting with a film, or pasting of both of these. Moreover, the same adhesive may be used for adhesion of the film laminated on both surfaces of the first polarizing film 21, or different adhesives may be used. In order to reduce the number of members, it is preferable to use the same adhesive.

  In the production of the polarizing plate, a corona discharge treatment is applied to the surface of the protective film made of an acrylic resin and the protective film made of a resin other than the acrylic resin on the side bonded to the first polarizing film 21. It is preferable to give it. By performing the corona discharge treatment, the adhesive force between these films and the first polarizing film 21 can be increased. The corona discharge treatment is a treatment for activating the resin film disposed between the electrodes by discharging by applying a high voltage between the electrodes. The effect of the corona discharge treatment varies depending on the type of electrode, electrode interval, voltage, humidity, type of resin film used, etc., for example, the electrode interval is set to 1 to 5 mm, and the moving speed is set to about 3 to 20 m / min. It is preferable to do this. After the corona discharge treatment, the first polarizing film 21 is bonded to the treated surface via the adhesive as described above.

(Other configurations)
The first polarizing plate 20 thus obtained can be formed as a polarizing plate with an adhesive layer by forming an adhesive layer on the surface of the first inner protective film 23. Such a pressure-sensitive adhesive layer can be suitably used, for example, for bonding with the liquid crystal cell 40 when the first polarizing plate 20 is applied to the liquid crystal display device 1. When applied to the liquid crystal display device 1, the first polarizing plate 20 is preferably used by being bonded to the front side (viewing side) of the liquid crystal cell 40.

  As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, those using a base polymer such as an acrylic ester, methacrylic ester, butyl rubber, or silicone can be used. Although not particularly limited, based on (meth) acrylate esters such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate And polymers based on copolymers using two or more of these (meth) acrylic esters are preferably used. The pressure-sensitive adhesive usually has a polar monomer copolymerized in these base polymers. Examples of the polar monomer include (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, and (meth) acrylic acid 2. Examples thereof include monomers having a carboxyl group, a hydroxyl group, an amino group, an epoxy group, and the like, such as -hydroxypropyl, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate. The pressure-sensitive adhesive usually contains one or more cross-linking agents in addition to the base polymer. Examples of the crosslinking agent include a divalent or polyvalent metal salt that forms a carboxylic acid metal salt with a carboxyl group, a polyisocyanate compound that forms an amide bond with a carboxyl group, and the like.

  The thickness of the pressure-sensitive adhesive layer can be about 3 to 50 μm. When the pressure-sensitive adhesive layer is applied to the polarizing plate, a surface treatment such as corona treatment may be applied to the surface of the protective film of the polarizing plate. Moreover, when forming an adhesive layer, it is normal to cover the surface of an adhesive layer with a peeling film.

[Second polarizing plate]
The second polarizing plate 30 is formed by laminating a second inner protective film 33, a second polarizing film 31 made of polyvinyl alcohol resin, and a second outer protective film 35 in this order.

(Second polarizing film)
Specifically, the second polarizing film 31 is obtained by adsorbing and orienting a dichroic dye on a uniaxially stretched polyvinyl alcohol-based resin film, and the same description as that of the first polarizing film 21 is used. be able to. The first polarizing film 21 and the second polarizing film 31 may be the same or different with respect to the outer shape (thickness, etc.), material, and manufacturing method.

(Second inner protective film)
The second inner protective film 33 has a function of protecting the surface of the second polarizing film 31. As the 2nd inner side protective film 33, the non-orientation film which does not have a phase difference substantially in a plane or thickness direction like the 1st inner side protective film 23 mentioned above is preferable. The details of the non-oriented film are the same as those described in the first inner protective film 23, and thus detailed description thereof is omitted here.

  As described above, since the non-oriented film does not need to be stretched, the production cost is lower than that of the biaxially stretched film. Therefore, compared to the case where at least one biaxially stretched film is used by using low-cost non-oriented films as the first and second inner protective films 23 and 33 as in the present embodiment. The manufacturing cost of the liquid crystal display device 1 can be further reduced.

(Second outer protective film)
The second outer protective film 35 is not particularly limited as long as it is a film made of a transparent resin, and those described for the first outer protective film 25 can be similarly used. The first outer protective film 25 of the first polarizing plate 20 and the second outer protective film 35 of the second polarizing plate 30 may be the same with respect to the outer shape (thickness, etc.), material, and manufacturing method. May be different.

(Bonding of polarizing film and protective film)
In the second polarizing plate 30, the bonding between the second polarizing film 31 and the second inner protective film 33 or the second outer protective film 35 is the same method as that described for the first polarizing plate 20. Can be.

[Liquid Crystal Panel / Liquid Crystal Display]
FIG. 2 is a schematic cross-sectional view showing a liquid crystal panel and a liquid crystal display device using the set of polarizing plates of FIG. The liquid crystal panel 2 shown in this figure includes a liquid crystal cell 40 and a pair of polarizing plates 20 and 30 disposed on both sides thereof. The pair of polarizing plates includes the first polarizing plate 20 and the second polarizing plate 30 described above. The first polarizing plate 20 is disposed on the front side (viewing side) of the liquid crystal cell 40 with the first inner protective film 23 inside, and the second polarizing plate 30 is provided with the second inner protective film 33. On the inner side, the liquid crystal cell 40 is disposed on the back side. The liquid crystal display device 1 includes a liquid crystal panel 2, a backlight 10, and a light diffusion plate 50. A light diffusing plate 50 and a backlight 10 are arranged in order from the side closer to the second polarizing plate 30 on the back side of the second polarizing plate 30 of the liquid crystal panel 2.

  The liquid crystal panel 2 and the liquid crystal display device 1 can be manufactured by a known method. As a manufacturing method of the liquid crystal panel 2, it can manufacture by cutting out the elongate polarizing plate wound by roll shape to a sheet | seat, and bonding to the liquid crystal cell 40. FIG.

  The liquid crystal cell 40 used in the present invention is not particularly limited, but is preferably a liquid crystal cell 40 in an IPS mode or a liquid crystal driving mode using a blue phase liquid crystal. In these modes, since there is little fluctuation in luminance when viewed from the front of the liquid crystal display device 1 and when viewed from an oblique direction, it is not necessary to widen the viewing angle using a biaxial retardation film. For this reason, as the first and second inner protective films 23 and 33 arranged on both the viewing side and the back side of the liquid crystal cell 40, a non-oriented film can be applied to reduce the manufacturing cost. This is because it can. In particular, in the case of the liquid crystal cell 40 using the liquid crystal of the blue phase, there is no dependence on the viewing angle in the dark state in principle, so that no alignment film is required. 2 is suitable.

(Backlight)
The backlight 10 is a device that illuminates the liquid crystal cell 40. Examples of the backlight 10 include an edge light type and a direct type. In the edge light type, the liquid crystal cell 40 is irradiated with light through a light guide plate from a light source such as a cold cathode tube arranged on a side surface. In the direct type, a light source is disposed on the back side of the liquid crystal cell 40 to irradiate the liquid crystal cell 40 with light. As the type of the backlight 10, a backlight according to the application of the liquid crystal display device 1 can be appropriately adopted.

(Light diffusion plate)
The light diffusing plate 50 is an optical member having a function of diffusing light from the backlight 10, for example, a material in which particles as a light diffusing agent are dispersed in a thermoplastic resin to impart light diffusibility, thermoplasticity The surface of the resin plate may be uneven to provide light diffusivity, or the surface of the thermoplastic resin plate may be provided with a resin composition coating layer in which particles are dispersed to provide light diffusibility. . The thickness can be about 0.1-5 mm. Further, between the light diffusion plate 50 and the liquid crystal panel 2, a prism sheet (also called a light condensing sheet, for example, “BEF” manufactured by 3M) or the like, a brightness enhancement sheet (for example, “DBEF manufactured by 3M, etc.) Etc.), a sheet exhibiting other optical functionality, such as a light diffusion sheet, can also be disposed. One or more sheets of other optical functionalities can be arranged as required. Further, as the light diffusing plate 50, for example, a light diffusion plate such as a laminated integrated product of a prism sheet having a cylindrical shape on the surface and a light diffusing plate (for example, one described in JP 2006-284597 A). It is also possible to use an optical sheet in which other functions are combined with each other.

  In the embodiment described above, the first polarizing plate 20 is disposed on the viewing side and the second polarizing plate 30 is disposed on the back side of the two planes of the liquid crystal cell 40. It is not limited to this, The structure by which the 2nd polarizing plate 30 is arrange | positioned at the visual recognition side and the 1st polarizing plate 20 is arrange | positioned at the back side may be sufficient.

  Further, in the above-described embodiment, both the first outer protective film 25 and the second outer protective film 35 are formed of a protective film made of a stretched acrylic resin. Only the outer protective film may be a protective film made of a stretched acrylic resin. In this case, the other outer protective film may be a resin film made of a material other than acrylic, or may be an unstretched acrylic resin film.

  Such a resin film may have an antiglare property and a hard coat property like the antiglare film 24 described above, or may be another functional film. Examples of other functions include antireflection, low reflection, antifouling, and antistatic. When such a resin film is arranged on the viewer side, a film having one or more functions among antiglare, hard coat, antireflection, low reflection, antifouling, antistatic functions and the like. Is preferably used. On the other hand, when a resin film is arrange | positioned at the back side, the film which has any 1 type or 2 types or more functions among functions, such as glare-proof and a hard coat, is preferable. Hereinafter, the resin film provided with antireflection, low reflection, antifouling, and antistatic functions will be described.

[Anti-reflective / low-reflective properties (anti-reflective / low-reflective film)]
The antireflection film is generally formed by stretching a low refractive index layer that is also an antifouling layer, and at least one layer having a higher refractive index than that of the low refractive index layer (that is, a high refractive index layer or a medium refractive index layer). It is provided on a resin film such as unstretched cellulose acetate.

  As a multilayer film in which transparent thin films of inorganic compounds (metal oxides, etc.) with different refractive indexes are laminated, colloid by chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, metal compound sol / gel method such as metal alkoxide And a method of forming a thin film by post-treatment (ultraviolet irradiation: JP-A-9-157855, plasma treatment: JP-A-2002-327310) after forming the metal oxide particle film.

  On the other hand, various antireflection films have been proposed as antireflection films having high productivity, in which a thin film in which inorganic particles are dispersed in a matrix is laminated. Moreover, the antireflection film which consists of an anti-glare antireflection layer which gave the shape of the fine unevenness | corrugation to the uppermost layer surface of such an antireflection film by application | coating is also mentioned.

[Granting antifouling properties]
For the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipperiness, a known silicone-based or fluorine-based antifouling agent, slipping agent, etc., may be appropriately added to a cellulose acetate-based resin film. You can also. When these additives are added, it is preferably added in the range of 0.01 to 20% by mass, more preferably in the range of 0.05 to 10% by mass of the total solid content of the low n layer. Particularly preferably 0.1 to 5% by mass.

  Preferable examples of the silicone compound include those having a substituent at the terminal and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, the amount is%. Examples of preferred silicone compounds are X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821 (above trade names), Chisso Corporation, FM-0725, FM-7725, DMS-U22, RMS-033, RMS-083, UMS-182 (above trade names) and the like. It is not limited to.

As the fluorine compound, a compound having a fluoroalkyl group is preferable. The fluoroalkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and a straight chain (for example, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ) ₄ H, etc.), even branched structures (eg, CH (CF ₃ ) ₂ , CH ₂ CF (CF ₃ ) ₂ , CH (CH ₃ ) CF ₂ CF ₃ , CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H, etc.), alicyclic structures (preferably 5-membered or 6-membered rings such as perfluorocyclohexyl group, perfluorocyclopentyl, etc. Group or an alkyl group substituted with these, and may have an ether bond (for example, CH ₂ OCH ₂ CF ₂ CF ₃ , CH ₂ CH ₂ OCH ₂ C ₄ F ₈ H, CH ₂ CH ₂ OC _{2 CH 2 C 8 F 17,} CH 2 CH 2 OCF 2 CF 2 OCF 2 CF 2 H , etc.). A plurality of the fluoroalkyl groups may be contained in the same molecule.

  The fluorine-based compound preferably further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, Ltd., R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink Co., Ltd., Megafac F-171. , F-172, F-179A, and defender MCF-300 (named above), but are not limited thereto.

[Addition of dustproof / antistatic layer]
For the purpose of imparting dustproof and antistatic properties, a known antistatic agent such as a cationic surfactant or a polyoxyalkylene compound, an antistatic agent, or the like can be appropriately added to a resin film such as cellulose acetate. . These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass, more preferably in the range of 0.05 to 10% by mass of the total solid content of the low n layer. Particularly preferably 0.1 to 5% by mass. Examples of preferred compounds include, but are not limited to, Dainippon Ink Co., Ltd., MegaFace F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

<Other embodiments>
In 1st Embodiment mentioned above, although the 1st polarizing plate 20 demonstrated the 1st inner side protective film 23 and the 2nd polarizing plate 30 demonstrated the example of the layer structure provided with the 2nd inner side protective film 33, According to the set of polarizing plates of the present invention, a layer configuration not including these inner protective films 23 and 33 may be employed. Hereinafter, this embodiment will be described.

  FIG. 3 is a schematic cross-sectional view illustrating a set of polarizing plates, a liquid crystal panel, and a liquid crystal display device according to another embodiment. As shown in this figure, the set of polarizing plates of the present embodiment is composed of a first polarizing plate 20 and a second polarizing plate 30, of which the first polarizing plate 20 includes the first polarizing film 21 and the first polarizing plate 21. From the outer protective film 25, the second polarizing plate 30 is composed of a second polarizing film 31 and a second outer protective film 35. That is, unlike the first embodiment, the first inner protective film 23 and the second inner protective film 33 are not provided in the present embodiment. Thus, by setting it as the structure which is not equipped with the inner side protection films 23 and 33, it becomes possible to simplify a layer structure and can aim at reduction of manufacturing cost.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 2 Liquid crystal panel, 10 Backlight, 20 1st polarizing plate, 21 1st polarizing film, 23 1st inner side protective film, 24 Anti-glare film, 25 1st outer side protective film, 26 Hard coat layer, 30 second polarizing plate, 31 second polarizing film, 33 second inner protective film, 35 second outer protective film, 40 liquid crystal cell, 50 light diffusion plate

Claims (8)

A set of polarizing plates for liquid crystal display comprising a first polarizing plate disposed on one surface side of the liquid crystal cell and a second polarizing plate disposed on the other surface side,
The first polarizing plate is formed by laminating a first polarizing film made of a polyvinyl alcohol-based resin and a first outer protective film made of a transparent resin in this order,
The second polarizing plate is formed by laminating a second polarizing film made of a polyvinyl alcohol-based resin and a second outer protective film made of a transparent resin,
At least one of the first outer protective film and the second outer protective film is made of a stretched acrylic resin.   The acrylic resin is uniaxially stretched in a machine flow direction (MD) or a direction (TD) orthogonal to the machine flow direction, or a direction (TD) orthogonal to the machine flow direction (MD) and the machine flow direction. The polarizing plate set according to claim 1, which is biaxially stretched simultaneously or sequentially.   The first polarizing film and the first outer protective film, and the second polarizing film and the second outer protective film are each composed of a resin composition containing an epoxy compound that is cured by active energy rays. The set of polarizing plates according to claim 1 or 2, which are bonded together.   4. The acrylic resin composition according to claim 1, wherein the acrylic resin comprises an acrylic resin composition in which 25 to 45 wt% of rubber elastic body particles having a number average particle diameter of 10 to 300 nm are blended in a transparent acrylic resin. A set of the polarizing plates described. In the first polarizing plate, a first inner protective film is laminated on a surface of the first polarizing film opposite to a side on which the first outer protective film is laminated,
The first inner protective film has an internal haze value of 0.5% or less and an external haze value of 5% or less, an in-plane retardation value at a wavelength of 590 nm of 10 nm or less, and a thickness direction at a wavelength of 590 nm. The set of the polarizing plate in any one of Claims 1-4 whose absolute value of phase difference value of is 10 nm or less. In the second polarizing plate, a second inner protective film is laminated on a surface of the second polarizing film opposite to the side on which the second outer protective film is laminated,
The second inner protective film has an internal haze value of 0.5% or less and an external haze value of 5% or less, an in-plane retardation value at a wavelength of 590 nm of 10 nm or less, and a thickness direction at a wavelength of 590 nm. The set of the polarizing plate in any one of Claims 1-5 whose absolute value of phase difference value of is 10 nm or less. It consists of a liquid crystal cell and a pair of polarizing plates arranged on both sides thereof,
The pair of polarizing plates is a set of polarizing plates according to any one of claims 1 to 6,
The liquid crystal panel, wherein the first outer protective film and the second outer protective film are laminated on a side farthest from the liquid crystal cell. A backlight, a light diffusing plate, and a liquid crystal panel according to claim 7,
The liquid crystal display device in which the backlight, the light diffusing plate, the first polarizing plate, the liquid crystal cell, and the second polarizing plate are arranged in this order.

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