TW201302465A - Polarizing plate - Google Patents

Abstract

Provided is a polarizing plate including a transparent protective film composed of a propylenic resin, a polarizing film composed of a polyvinyl alcoholic resin adsorbed and oriented by a dichroic coloring matter, and a biaxial phase retardation film, in which therse film laminated in that order, wherein the propylenic resin contains a UV-absorbing agent at least including a triazine type compound represented the following formula (I), wherein the content of the triazine type compound is less than1 % by weight in the propylenic resin, and the transmission rate of light having wavelength between 320 to 330nm is 1% or less.

Description

Polarizer

The present invention relates to a polarizing plate in which a transparent protective film made of a propylene-based resin film is laminated on at least one surface of a polarizing film of a polyvinyl alcohol-based resin.

The polarizing plate is one of important constituent members of a liquid crystal display device such as a liquid crystal television, a liquid crystal monitor, or a personal computer. In the polarizing plate, a transparent protective film is laminated on one surface or both surfaces of a polarizing film composed of a polyvinyl alcohol-based resin which is adsorbed by a dichroic dye, and is represented by, for example, cellulose triacetate. It is composed of a cellulose acetate-based transparent protective film. There is also a case where a retardation film made of a norbornene-based resin or the like is laminated on one surface of the polarizing film via an adhesive layer.

However, when a hydrophilic transparent protective film such as a cellulose triacetate film is used, the amount of moisture of the polarizing film composed of the polyvinyl alcohol-based resin is affected under high temperature and high humidity conditions, and the performance as a polarizing plate is somewhat changed. Therefore, a polarizing plate having a configuration in which a transparent protective film made of a hydrophobic resin such as a propylene-based resin is used instead of a transparent protective film made of a hydrophilic resin, and the influence of the environment is extremely suppressed (for example, JP2009-258588-A) is reviewed. Wait).

On the other hand, the polarizing plate is responsible for protecting the liquid crystal cells in the liquid crystal display device from the light, and is often provided with a UV absorber added to the transparent protective film laminated on the polarizing film to provide a function of blocking ultraviolet rays of 400 nm or less. However, when an ultraviolet absorber is added to the propylene-based resin film shown in JP2009-258588-A, the interface of the ultraviolet absorber at the interface with the adhesive layer The bleed accumulation has the possibility of lowering the bonding strength of the transparent protective film and the polarizing film.

An object of the present invention is to provide a propylene-based resin film which is provided with an ultraviolet ray blocking function by addition of an ultraviolet ray absorbing agent, and a polarizing film laminated on a polarizing film via an adhesive layer, and an ultraviolet absorbing agent from the propylene-based resin film The overflow is suppressed by the polarizing plate.

The invention includes the following.

[1] A polarizing plate in which a transparent protective film containing a propylene resin, a polarizing film in which a dichroic dye is adsorbed and a polyvinyl alcohol-based resin, and a biaxial retardation film are sequentially laminated. The resin contains at least the following formula (I): (wherein R ¹ represents an alkyl group having 1 to 12 carbon atoms, and R ² represents hydrogen or an alkyl group having 1 to 8 carbon atoms) (triazine) is a UV absorber of a compound, the aforementioned three The content of the compound is less than 1% by weight in the propylene-based resin, and the transmittance of light having a wavelength of from 320 to 330 nm is 1% or less.

[2] The polarizing plate according to [1], wherein the propylene-based resin contains a ratio of 0.5 to 0.8% by weight, and only contains the third formula (I) A UV absorber of a compound.

[3] The polarizing plate according to the above [1], wherein the propylene-based resin contains three of the formula (I) in a ratio of 0.3 to 0.9% by weight. The compound and the benzotriazole-based ultraviolet absorbing compound in a ratio of 0.1 to 0.7% by weight have a light transmittance of 1% or less at a wavelength between 310 and 350 nm.

According to the present invention, there is provided a polarizing plate which does not have a transparent protective film made of a propylene-based resin in a high-temperature environment or a high-temperature and high-humidity environment, has a good ultraviolet blocking performance, and has a small influence on a polarizing film in a use environment. . The liquid crystal display device to which such a polarizing plate of the present invention is applied has excellent durability and good display performance stability.

(polarizer)

In the polarizing plate of the present invention, a transparent protective film made of a propylene resin, a polarizing film in which a dichroic dye is adsorbed to a polyvinyl alcohol resin, and a biaxial retardation film are laminated in this order. On the outer side of the biaxial retardation film, an adhesive layer is usually further provided.

(transparent protective film made of propylene resin)

The transparent protective film used for the polarizing plate of the present invention is obtained by molding into a film form of a propylene-based resin containing 90% by weight or more of a constituent unit composed of propylene.

The propylene-based resin may be a single polymer of propylene or a copolymer of propylene and another monomer copolymerizable therewith. Moreover, these can be used in combination. Examples of the other monomer copolymerizable with propylene include ethylene and an α-olefin. The α-olefin is a carbon number of 4 or more, and more preferably an α-olefin having 4 to 12 carbon atoms. Specific examples of the α-olefin having 4 to 12 carbon atoms, for example, linear monoolefins such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene a branched monoolefin such as 3-methyl-1-butene, 3-methyl-1-pentene or 4-methyl-1-pentene; vinylcyclohexane or the like. The copolymer of propylene and other monomers copolymerizable therewith may be a random copolymer and may be a block copolymer.

When the propylene resin contains the above copolymer, specific examples of the copolymer are, for example, selected from the group consisting of propylene-ethylene irregular copolymer, propylene-1-butene irregular copolymer, and propylene-ethylene-1-butene irregular copolymerization. A binary to terpolymer of one or two or more kinds of monomers in which propylene and the above-mentioned ethylene and the α-olefin having 4 to 12 carbon atoms are grouped.

When the propylene resin contains the above copolymer, the constituent unit derived from propylene can be selected according to characteristics such as heat resistance. In the case where high heat resistance is required, it is preferable to contain a large amount of a constituent unit derived from propylene, and specifically, it is 96% by weight or more. In addition, the content ratio of the constituent unit derived from the other monomer in the copolymer can be performed by infrared rays (IR) according to the method described in the "Handbook of Polymer Analysis" (1995, issued by Kiyoshiya Shoten). Determined by the measurement of the spectrum.

Further, the stereoregularity of the propylene-based individual polymer and the propylene-based copolymer may be any of isotactic, syndiotactic, and atactic, and is rigid and transparent from being formed into a film. From the standpoint of good balance of properties, it is desirable to have a high propylene group Compound.

In the present invention, the propylene-based resin may be a polymer or a copolymer polymerized using a conventional polymerization catalyst, and examples of the catalyst for polymerization include the following.

(A) a Ti-Mg catalyst composed of a solid catalyst component containing magnesium, titanium and halogen as essential components; (B) a solid catalyst component containing magnesium, titanium and halogen as essential components, and an organoaluminum compound and A catalyst system in which a third component such as an electron-donating compound is required; (C) a metallocene catalyst or the like.

The solid catalyst component of the above (A) may, for example, be a catalyst system described in JPS 61-218606-A, JPS 61-287904-A, or JPH 07-216017-A. Further, as a preferred example of the organic aluminum compound of the catalyst system of the above (B), for example, a mixture of triethyl aluminum, triisobutyl aluminum, triethyl aluminum, and diethyl aluminum chloride may be mentioned. A preferred example of the electron-donating compound, such as tetraethyl dialumoxane, may, for example, be cyclohexylethyldimethoxydecane or butylbutyldimethoxydecane. 3 butyl ethyl dimethoxy decane, dicyclopentyl dimethoxy decane, and the like. In addition, examples of the metallocene catalyst of the above (C) include a catalyst system described in JP2587251-B, JP2627669-B, and JP2668732-B.

A propylene-based resin can be polymerized by, for example, a solution using an inert solvent represented by a hydrocarbon compound such as hexane, heptane, octane, decane, cyclohexane, methylcyclohexane, benzene, toluene or xylene. Method, using liquid monomer as a solution The bulk polymerization method of the agent is produced by a gas phase polymerization method in which a monomer of a gas is polymerized as it is. By the polymerization of these methods, it can be carried out in batches and can be carried out continuously.

The transparent protective film made of a propylene resin used in the present invention can be extruded into a film form by extrusion by a melt extrusion method. In this case, the propylene resin is at a temperature according to JIS K7210. The melt flow rate (MFR) measured at 230 ° C and a load of 21.18 N is preferably in the range of 1 to 30 g/10 min, more preferably in the range of 1 to 20 g/10 min, and a range of 1.5 to 15 g/10 min. More ideal inside. By using the MFR in the range of the propylene-based resin in the range, it is possible to reduce the burden on the extruder and to easily produce a film having a uniform thickness in the film formation by melt extrusion.

In the present invention, the transparent protective film made of a propylene-based resin bonded to the surface of one side of the polarizing film, as described above, contains at least three of the following formula (I) as the ultraviolet absorber. The compound has a light transmittance of 1% or less between wavelengths of 320 to 330 nm.

Above three When the content of the compound is 1% by weight or more in the propylene resin, the amount of the compound may be less than 1% by weight in the propylene resin because it may overflow under high temperature and high humidity. As the ultraviolet absorber, when only the three types shown in the above formula (I) are used In the case of a compound, the three in the propylene resin The amount of the compound is preferably in the range of 0.5 to 0.8% by weight. When the ultraviolet absorber is only the three shown in the above formula (I) In the case of a compound, when the amount is less than 0.5% by weight, the ability to block ultraviolet rays is insufficient, and it becomes difficult to make the transmittance of light between the wavelengths of 320 to 330 nm 1% or less. On the other hand, when the amount exceeds 0.8% by weight, it overflows under high temperature/high humidity conditions, and the transparency is impaired. For this reason, when the ultraviolet absorber is only the three shown in the above formula (I) In the case of a compound, the three A preferred compounding amount of the compound is from 0.5 to 0.8% by weight.

In the formula (I), R ¹ is an alkyl group having 1 to 12 carbon atoms, and when the number of carbon atoms is 3 or more, it may be a straight chain or a branched form. Examples of such an alkyl group may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a t-butyl group, a ternary butyl group or a n-pentyl group. Isoamyl, 3 pentyl, n-hexyl, n-heptyl, n-octyl, isooctyl, 3 octyl, 2-ethylhexyl, 3-ethylhexyl, n-decyl, iso Mercapto, n-decyl, n-undecyl, n-dodecyl and the like.

Further, in the formula (I), R ² is hydrogen or an alkyl group having 1 to 8 carbon atoms, and when the number of carbon atoms is 3 or more, it may be a straight chain or a branched form. Examples of such alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, ternary butyl, n-pentyl, isopentyl And a 3th pentyl group, a n-hexyl group, a n-heptyl group, a n-octyl group, an isooctyl group, a 3rd octyl group, a 2-ethylhexyl group, etc.

As the three shown in the above formula (I) Preferred examples of the compound are, for example, the following compounds.

2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-three [In the formula (I), R ¹ = octyl, a compound of R ² =H], 2,4,6-tris(4-decyloxy-2-hydroxy-3-methylphenyl)-1, 3,5-three [In the formula (I), R ¹ = mercapto group, R ² = 3-methyl compound], 2,4,6-tris(4-hexyloxy-2-hydroxy-3-methylphenyl) -1,3,5-three [In the formula (I), a compound wherein R ¹ = hexyl, R ² = 3-methyl], 2,4,6-tris[4-(3-ethylhexyloxy)-2-hydroxy-3- Methyl phenyl]-1,3,5-three [In the formula (I), R ¹ = 3-ethylhexyl, a compound of R ² = H] and the like.

In addition to the three shown in formula (I) In addition to the compound, other ultraviolet absorbing compounds may be used, and the transmittance of light having a wavelength between 320 and 330 nm may be 1% or less. As with three The preferred ultraviolet absorbing compound to be used in combination with the compound may, for example, be a benzotriazole compound. By using a benzotriazole-based ultraviolet absorbing compound in combination, the ability to block ultraviolet rays in a short-wavelength region of 300 nm or less can be imparted, and the effect of suppressing the overflow of the formulated ultraviolet absorber can be imparted. In this case, the preferred blending amount is three in the formula (I) with respect to the propylene-based resin. The compound is 0.3 to 0.9% by weight, and the benzotriazole-based ultraviolet absorbing compound is in the range of 0.1 to 0.7% by weight.

The benzotriazole-based ultraviolet absorbing compound is a compound having a benzotriazole skeleton, preferably a 2-(2-hydroxyphenyl)-2H-benzotriazole skeleton, and having an ultraviolet absorbing ability. Among the benzotriazole-based ultraviolet absorbing compounds, those having a large molecular weight are, for example, those having a molecular weight of 350 or more. Specifically, for example, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3, which has the structure of the following formula (II), may be mentioned. 3-tetramethylbutyl)phenol], 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H- having the structure of the following formula (III) Benzotriazole, 2-(3,5-di 3pentyl-2-hydroxyphenyl)-2H-benzotriazole having the structure of the following formula (IV), having the structure of the following formula (V) 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydroindenidomethyl)phenol (2-(2H-benzotriazol- 2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidyl methyl) phenol), 6-(2H-benzotriazol-2-yl)- having the structure of the following formula (VI) 4-tert-octyl-6'-t-butyl-4'-methyl-2,2'-methylene bisphenol.

Three shown in formula (I) In addition, a other ultraviolet absorbing compound may be added thereto, for example, a benzotriazole-based ultraviolet absorbing compound may be added to the propylene-based resin, and in order to produce a transparent protective film made of a propylene-based resin, for example, the following method may be employed. .

(1) A pellet composed of a resin composition containing 1 to 10 parts by weight of an ultraviolet absorber with respect to 100 parts by weight of the propylene resin (referred to as "ultraviolet absorbent masterbatch pellet" (master batch) In the case of pellet), the propylene resin particles are melt-mixed, the ultraviolet absorber is used as a method to form a film into a film, and (2) a propylene resin is prepared in advance to prepare a predetermined amount of ultraviolet absorber. The granules of the propylene-based resin composition are obtained by melt-kneading the granules to form a film, and (3) a method of forming a film by melt-kneading in a state where a predetermined amount of the ultraviolet absorbing agent is blended in the propylene-based resin.

Among these, from the viewpoint of the uniformity of the transparent protective film made of the propylene-based resin and the production cost, as in the above (1), the ultraviolet absorbing agent masterbatch particles are prepared in advance, and the ultraviolet ray is not formulated. The method of melt-kneading the propylene-based resin particles of the absorbent is most preferable.

The preparation of the ultraviolet absorber masterbatch particles can be carried out using a uniaxial or biaxial extruder, and from the viewpoint of increasing the shear rate to more uniformly disperse the ultraviolet absorber in the propylene resin, the use of biaxial extrusion The machine is ideal. At the time of extrusion, the temperature of the propylene-based resin in the die portion of the extruder is preferably in the range of 180 to 260 °C. When the temperature exceeds 260 ° C, the resin is deteriorated. In addition, when the temperature exceeds 210 ° C, it is desirable to add an antioxidant such as a phenol system or a phosphorus system from the viewpoint of suppressing deterioration of the resin. By using a phenolic antioxidant together with a phosphorus-based antioxidant, it is more preferable to further enhance the effect of suppressing deterioration of the resin. Formulated for anti-oxidation In the case of the amount of the agent, it is sufficient that the amount is about 1 part by weight based on 100 parts by weight of the propylene resin.

In the propylene-based resin, a conventional additive can be blended without departing from the effects of the present invention. As the additive, for example, an antioxidant and three compounds represented by the formula (I) A UV absorber, an antistatic agent, a slip agent, a nucleating agent, an antifogging agent, an anti-caking agent, and the like other than the compound and the benzotriazole-based ultraviolet absorbing compound. Examples of the antioxidant include a phenolic antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and a hindered amine-based light stabilizer. Further, for example, a phenolic antioxidant mechanism and a phosphorus-based antioxidant can be used in one molecule. A complex antioxidant of the unit of oxidation mechanism. As the three shown in formula (I) Examples of the ultraviolet absorber other than the benzotriazole-based ultraviolet absorbing compound include a 2-hydroxydiphenyl ketone derivative and a benzoate ultraviolet absorbing compound. The antistatic agent may be any of a polymer type, an oligomer type, and a monomer type. Examples of the slip agent include higher fatty acids such as erucamide and oleic acid amide, higher fatty acids such as decylamine and stearic acid, and salts thereof. As the anti-caking agent, a spherical shape or a fine particle close to the shape can be used, regardless of the inorganic or organic type.

Further, in the propylene-based resin, a nucleating agent can be added without departing from the effects of the present invention. When a nucleating agent is added, it may be any of an inorganic nucleating agent and an organic nucleating agent. Examples of the inorganic nucleating agent include talc, clay, and calcium carbonate. Further, examples of the organic nucleating agent include metal salts such as metal salts of carboxylic acids and metal salts of aromatic phosphoric acid, triterpenoids, sorbitol, high density polyethylene, and poly-3-methyl. Butylene-1, polycyclopentene, polyvinylcyclohexane, and the like. Among these, organic The nucleating agent is preferably a carboxylic acid metal salt or a trisamine or a high density polyethylene. Further, the amount of the nucleating agent added is preferably from 0.01 to 3% by weight, more preferably from 0.05 to 1.5% by weight, based on the propylene-based resin. Further, the above additives may be used in combination of plural kinds.

The propylene-based resin used in the present invention is preferably formed into a film shape by a melt extrusion method. In the melt extrusion method, a powdery or granular propylene resin raw material is supplied to an extruder heated to about 180 to 300 ° C, and melted and kneaded by a screw of an extruder, and a T-die is used. The slit of (T die) is melt-extruded into a sheet shape, and then a method of producing a film by contacting a cooling roll by various means and cooling.

The temperature of the extruded molten flake-form propylene-based resin is about 180 to 300 °C.

When the temperature of the molten flakes at this time is lower than 180 ° C, the ductility is insufficient, and the thickness of the obtained film becomes uneven, which may become a film having a non-uniform phase difference. Further, when the temperature exceeds 300 ° C, deterioration or decomposition of the resin is likely to occur, and bubbles or carbides are formed in the sheet.

The extruder can be a single-shaft extruder or a 2-axis extruder. For example, in the case of using a single-axis extruder, the ratio L/D of the screw length L and the diameter D is about 24 to 36, the space volume V ₁ of the screw groove of the resin supply portion, and the space volume of the screw groove of the resin metering portion. The ratio of V ₂ (V ₁ /V ₂ ) is about 1.5 to 4, and a kneading portion having a full flight type, a barrier type, and a Maddock type can be used. a screw of the form etc. From the viewpoint of suppressing deterioration, decomposition, and uniform melt kneading of the propylene resin, it is preferable to use a screw having an L/D of 28 to 36 and a compression ratio V ₁ /V ₂ of 2 to 3. Further, in order to suppress deterioration or decomposition of the propylene resin, nitrogen purge or the like is performed, and oxygen in the extruder is preferably removed. Furthermore, at the front end of the extruder, set a diameter of 1 to 5 mm The orifice is preferably used to increase the resin pressure at the front end portion of the extruder. Increasing the resin pressure at the tip end portion of the extruder by providing the orifice means increasing the back pressure of the tip end portion, thereby improving the uniformity of the melt kneading and improving the extrusion stability. The diameter of the orifice used is preferably 2 to 4 mm .

In the T-die used for extrusion, the flow path is a coat hanger, and the flow rate, pressure, etc. of the molten propylene resin in the width direction of the slit portion of the T-die are used as uniformly as possible. The balancer is ideal. Further, on the surface of the flow path of the resin, it is preferable that there is no fine step or damage, and the lip portion thereof may be plated with hard chrome, and may have fluorine-containing or polyoxygen oxynitrene immersed in a fluorine-based material or a polyfluorene-based material. Electroplating such as electroplating of a material such as electroplating with a molten propylene-based resin is preferable, and it is preferable to perform thermal spraying using a hard material such as tungsten carbide. Further, the lip portion is preferably a surface having a surface roughness of 0.1 S or less which has a polished surface roughness of less than 0.1 S, and is polished to a thickness of 0.3 mm at the front end of the lip. The following sharp edge shapes are preferred. By using a T-die having the lip as described above, generation of eyelids can be suppressed, and at the same time, a die line can be suppressed, and a resin film having excellent appearance uniformity can be easily obtained.

Further, from the viewpoint of suppressing the extrusion change of the propylene-based resin, a gear pump is installed between the extruder and the T-die via an adaptor, and the pressure is stably supplied. Resin is preferred for T-die. The pressure at this time is preferably within a range of 0.1 MPa. In order to achieve this change value, the gear pump is preferably a direct-acting type, and it is preferable to use a gear pump having a number of gears of two to three transfer resins for cutting off the phase type.

Further, in order to remove foreign matter contained in the propylene resin, it is preferable to provide a leaf disc filter. The number of the disc filters and the filtration area per sheet can be arbitrarily selected depending on the viscosity and the amount of extrusion (flow rate) of the molten propylene resin and the heat resistance of the resin. In the case of the propylene-based resin film used in the present invention, a filter having a foreign matter having a foreign matter content of 98% or more and a foreign matter size of 10 μm or less is used, and the amount of foreign matter in the film can be reduced, thereby improving the film thickness. Quality, so it is ideal. For the same reason, the filtration accuracy is preferably 5 μm or less, and more preferably 3 μm or less. Further, the installation position of the disk filter is preferably set in accordance with the order of the extruder, the gear pump, the disk filter, and the T-die, from the viewpoint of stably removing foreign matter.

The molten flaky propylene-based resin extruded from the T-die is then contacted with a metal cooling roller (also referred to as a chill roller or a casting roller), and is brought into close contact with the cooling roller to be cooled. At this time, the adhesion to the cooling roller affects the transparency. For the adhesion of the cooling roller, for example, a) is applied to the molten flaky propylene resin to be electrostatically sealed, and is cooled in contact with a mirror-shaped cooling roller; b) the molten flaky propylene resin is pressed. a method of cooling between a cooling roller having a mirror surface and a mirror-shaped elastically deformable metal roller (also referred to as a contact roller) or a metal strip, and cooling with a cooling roller; c) When the molten flaky propylene resin contacts the cooling roller, it is carried out by a conventional method such as a method in which air blown from an air chamber is adhered to the cooling roller and cooled.

a) The method is called a method of electrostatic pinning, and only at both end portions (referred to as ear portions) of the film of molten propylene resin extruded from a T-die, or in the foregoing film A front-end portion in the width direction of the object is provided with a power source of a core shape, a wire shape, or a strip shape, and a high-frequency power source is used to apply a high voltage to the molten propylene resin, and is electrostatically charged to contact the cooling roller to be cooled and solidified. In this manner, it is less likely to cause chattering of the film from the lip portion of the T-die to the portion where the molten propylene resin is in contact with the cooling roller (referred to as an air gap), or the length of the unstable air gap can be shortened. It is an ideal way because it is easy to ensure the uniformity of the film.

a) The cooling roller used in the mode has a tendency to transfer to the surface of the film due to the surface of the cooling roller, and the surface of the roller preferably has a surface roughness of 0.5 S or less. Further, the surface material is a conductive material such as hard chrome plating or thermal spraying such as tungsten carbide, and it is preferable to thermally spray the surface such as chrome oxide which is not energized.

b) The method is called contact roller forming, which is a film of molten propylene resin extruded from a T-die, which is sandwiched between a cooling roller and an elastically deformable metal roller or metal strip. The film is adhered to the cooling roller to cool the cured film to obtain a film having good transparency. The elastically deformable metal roller refers to a roller surface having a thickness of 5 mm or less. When the molten propylene resin is sandwiched between the cooling roller, the resin is not accumulated (also referred to as a bank). Metal roller, the metal band refers to a metal ring with a thickness of 1 mm or less (endless) Belt), which is supported by a rubber roller or a metal roller and is rotated, and a film of molten propylene resin is sandwiched between the cooling roller and the cooling roller. In the case of this type, it is preferable to use a crystalline resin which does not lose transparency by cooling conditions, etc., from the viewpoint of the speed of formation speed becoming high.

b) The cooling roller and the elastically deformable metal roller or metal strip used in the method are preferably transferred to the surface of the film as the individual surfaces are, so that the surface of the roller has a surface roughness of 0.3 S or less. Further, due to strong pinching, the film material of the molten propylene-based resin is excessively adhered to the surface of the cooling roller or the elastically deformable metal roller or the metal strip due to the situation, and the detachment roller is deteriorated. From the viewpoint of this case, as a sealing treatment for microcracks covering the surface of hard chrome plating, a polyfluorinated material, a fluorine-based material, or a thermal sprayed surface of chromium oxide, tungsten carbide, or the like, or a sealing treatment thereof is used. The surface is ideal.

c) The method is called "air cavity method". When the film material of the molten propylene resin extruded from the T die contacts the cooling roller, the film of the molten propylene resin is on the side opposite to the cooling roller. The film is blown from the air chamber, whereby the film of the molten propylene resin is brought into close contact with the cooling roller. For the air chamber, a commercially available person can be used without any particular limitation. The blown air, for example, the air for manufacturing the environmental space, is separated by a high efficiency particulate air filter by a blower or the like (HEPA filter; high efficiency particulate air filter; Inhalation, in the air chamber, it is preferable to be in a pressurized state of 50 to 300 Pa. When the pressure in the air chamber is within this range, the pressure applied to the film is moderate, and the cooling roller is contacted from the lip of the T-die to the molten sheet-like resin. In the distance (air gap), the vibration does not occur, and the film can be stably formed. Of course, the stability of the film thickness and the like are also improved. For this reason, it is more preferable that the pressure in the air chamber becomes 100 to 200 Pa.

The cooling roller of the c) mode is preferably, for example, a range in which the surface temperature is adjusted to 0 to 60 °C. When the surface temperature of the cooling roller exceeds 60° C., the cooling and solidification of the molten flake propylene resin takes time, and the crystal component in the propylene resin grows, and the transparency of the obtained film is deteriorated. On the other hand, when the surface temperature of the cooling roller is lower than 0 ° C, the surface of the cooling roller is condensed to adhere water droplets, and the appearance of the obtained film tends to deteriorate.

c) The cooling roller of the embodiment has a tendency to be transferred to the propylene-based resin film, but is less than the above-mentioned a) or b), and when the mirror-shaped cooling roller is used, the propylene-based resin is melted. The air contained between the film and the cooling roller does not escape from the place, and it is difficult to form it uniformly. Therefore, in the case of the c) mode, the cooling roller uses a surface roughness of 0.6 to 4 s. From the viewpoint of improving the uniformity of the surface of the film, it is preferably from 0.8 to 2S.

The temperature of the cooling roller of the a) to c) mode is preferably, for example, a range in which the surface temperature is adjusted to 0 to 60 °C. When the surface temperature of the cooling roller exceeds 60° C., the cooling and solidification of the molten flake propylene resin takes time, and the crystal component in the propylene resin grows, and the transparency of the obtained film is deteriorated. On the other hand, when the surface temperature of the cooling roller is lower than 0 ° C, the surface of the cooling roller is condensed, and water droplets adhere thereto, and the appearance of the obtained film tends to deteriorate.

The processing speed at the time of producing a transparent protective film made of a propylene-based resin is determined according to the time required for cooling and solidifying the molten flaky propylene-based resin. When the diameter of the cooling roller to be used is increased, the distance from which the molten flaky propylene-based resin contacts the cooling roller becomes long, and it can be manufactured at a higher speed. Specifically, using 600 mm In the case of producing a transparent propylene-based resin film having a haze value of 1.0 or less, the metal cooling roller has a processing speed of at most about 50 m/min.

The transparent protective film made of a propylene-based resin used in the polarizing plate of the present invention can be obtained by forming the propylene-based resin into a film. The transparent protective film made of the propylene-based resin is preferably transparent, and specifically, the total haze value measured according to JIS K7136 is preferably 10% or less, more preferably 7% or less.

The transparent protective film made of a propylene resin of the polarizing plate of the present invention has a thickness of 5 to 200 μm. More preferably, it is 10 μm or more and 150 μm or less.

The transparent protective film made of a propylene-based resin of the polarizing plate of the present invention can be subjected to surface treatment such as corona treatment or plasma treatment without deteriorating the effects of the present invention. Moreover, it is possible to apply a coating method such as an antireflection layer and a hard coat layer equal to the surface.

A case where a transparent protective film made of a propylene-based resin of the polarizing plate of the present invention is produced by a melt extrusion method, or a high-concentration mother particle of the above-mentioned additive is melt-kneaded for production, and the like, uniaxial or biaxial extrusion It is preferable to seal the hopper or the die near the outlet with nitrogen gas from the viewpoint of protecting the propylene resin from oxidative degradation. Further, before the melt-extruded or melt-kneaded materials are supplied to the extruder separately, they are stored in a nitrogen atmosphere having an oxygen concentration of 1% by volume or less, and the oxygen molecules contained in the material are The inert gas such as nitrogen gas is substituted for suppressing deterioration of the resin, and most of them are effective, and it is preferably used in the present invention.

(A biaxial retardation film composed of a decene-based resin)

In the polarizing plate of the present invention, a biaxial retardation film is bonded to the surface of the polarizing film on the opposite side to the transparent protective film made of a propylene resin. As such a biaxial retardation film, the phase difference between the in-plane phase difference and the thickness direction is preferably a retardation film composed of a decene-based resin within a specific range. The film made of the norbornene-based resin used in the polarizing plate of the present invention is, for example, a monomer having a cyclic olefin (cycloolefin) such as a norbornene or a polycyclic norbornene-based monomer. A film composed of a thermoplastic resin of a unit. The norbornene-based resin may be a cyclic olefin, a cyclic olefin, or an aromatic compound having a vinyl group, in addition to the ring-opening polymer of the cycloolefin and the hydrogenated product of a ring-opening copolymer of two or more kinds of cyclic olefins. Addition copolymers. Moreover, it is also effective to introduce a polar base.

In the case of using a copolymer of a cyclic olefin and a chain olefin or an aromatic compound having a vinyl group, examples of the chain olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene. , α-methyl styrene, aryl substituted styrene, and the like. In such a copolymer, the monomer unit composed of a cyclic olefin is 50 mol% or less (more desirably 15 to 50 mol%). Particularly in the case of a terpolymer of a cyclic olefin, a chain olefin, and an aromatic compound having a vinyl group, the monomer unit composed of a cyclic olefin can be a relatively small amount as described above. In such a terpolymer, a monomer unit composed of a chain olefin is usually 5 to 80 mol%, and a monomer sheet composed of an aromatic compound having a vinyl group The element is usually 5 to 80 mol%.

For the cycloolefin resin, a suitable commercially available product can be suitably used, for example, TOPAS (manufactured by Topas Advanced Polymers GmbH), ARTON (manufactured by JSR), ZEONOR (made by Japan ZEON Co., Ltd.), and ZEONEX (Japan ZEON) )), APEL (Mitsui Chemical Co., Ltd.), etc. When forming a film of such a cycloolefin-based resin into a film, a conventional method such as a solvent casting method or a melt extrusion method is suitably used. In addition, for example, ESCENA (made by Sekisui Chemical Co., Ltd.), SCA40 (made by Sekisui Chemical Co., Ltd.), ZEONOR film (made by Japan ZEON Co., Ltd.), and ARTON film (made by JSR) can be used. A commercially available product of a film of a cycloolefin-based resin of a film is used as a transparent protective film.

The film made of the decene-based resin can be optically compensated for liquid crystal at least in one direction, and contributes to the expansion of the viewing angle of the liquid crystal display device. The biaxial retardation film composed of the norbornene-based resin used in the present invention has a refractive index in the in-plane retardation phase axis direction of the stretched film of n _x and a direction perpendicular to the retarded phase axis in the in-plane (advance phase) The refractive index of the axial direction is n _y , and the refractive index in the thickness direction is n _z , and the thickness of the film is d. The in-plane phase difference R ₀ and the thickness direction phase difference R _th of the film are represented by the following equations, respectively. , the in-plane phase difference R ₀ is in the range of 40 to 300 nm, (preferably 40 to 120 nm), and the thickness direction phase difference R _th is 80 to 300 nm (preferably 100 to 250 nm) Within the scope.

R ₀ = (n _{x -} n _y ) × d R _th = [(n _x + n _y )/2 - n _z ] × d

In the case where the in-plane retardation value R _{0 is} less than 40 nm or exceeds 300 nm, the viewing angle compensation capability of the panel tends to decrease. Further, in the case where the thickness direction phase difference _{Rth is} less than 80 nm or exceeds 300 nm, the viewing angle compensation ability of the panel tends to be lowered. In addition, the in-plane phase difference value R ₀ and the thickness direction phase difference value R _th can be measured, for example, using KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.).

In order to obtain a biaxial retardation film composed of a decene-based resin having a refractive index characteristic as described above, in addition to appropriately adjusting the stretching ratio and the stretching speed, the preheating temperature, the stretching temperature, and the heating set temperature may be appropriately selected. Various temperatures such as cooling temperature and their modes are sufficient. Such elongation characteristics can be obtained by stretching under mild conditions, for example, a stretching ratio of 1.05 to 1.6 times is preferable, and 1.1 to 1.5 times is more preferable. In the case of the biaxial stretching, the stretching ratio in the maximum extending direction may be within the above range.

The biaxial retardation film composed of the norbornene-based resin to be stretched by the present invention is not particularly limited in thickness, and is preferably in the range of 20 to 80 μm, and more preferably in the range of 40 to 80 μm. ideal. When the thickness of the biaxial retardation film composed of the norbornene-based resin is less than 20 μm, the film usability is difficult, and it is difficult to display a predetermined phase difference. On the other hand, the decene is lowered. When the thickness of the resin film exceeds 80 μm, the workability is deteriorated, the transparency is lowered, and the weight of the obtained polarizing plate is increased.

(adhesive)

The polarizing plate of the present invention is attached to both sides of the polarizing film Each of the agents is a transparent protective film made of a polypropylene resin and a biaxial retardation film made of, for example, the norbornene-based resin. In the polarizing plate of the present invention, the same kind of adhesive may be used for both surfaces of the polarizing film, or different kinds of adhesives may be used. A preferred adhesive agent from the viewpoint of thinning of the adhesive layer is, for example, a water-based adhesive, that is, one in which the adhesive component is dissolved in water or dispersed in water. Further, as a preferable adhesive agent from the viewpoint of the strength of the adhesive, for example, a photocurable adhesive which is itself cured by light can be mentioned.

The photocurable adhesive agent may, for example, be a mixture of a photocurable epoxy resin and a photocationic polymerization initiator. The combination of the adhesive and the propylene-based resin film to which the specific ultraviolet absorber is added is most preferable at the point of the strength. The photocurable adhesive is cured by irradiating an active energy ray to the photocurable adhesive. The light source of the active energy ray is not particularly limited, but an active energy ray having a light-emitting distribution with a wavelength of 400 nm or less is preferable, specifically, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, a black light, Microwave-excited mercury lamps, metal halide lamps, etc. are preferred.

The method of bonding the transparent protective film or the biaxial retardation film to the polarizing film is generally a conventional one, and may be, for example, a Meyer bar coating method or a gravure coating method. A comma coat method, a doctor blade method, a die coat method, a dip coat method, a spray method, etc., on a polarizing film and/or a sticker A method of applying an adhesive to the adhesion surface of the film on the polarizing film and overlapping the two. In the above coating method, from the thickness accuracy of the coating film, From the viewpoint of coating thickness, equipment size, and the like, a gravure coating method or a die coating method is preferable, and a gravure coating method is more preferable from the same viewpoint. The gravure coating method refers to a coating method of a gravure roller selected in consideration of a coating amount, and a gravure roller that rotates in an opposite direction with respect to a flow direction of the applied film, and a cavity is provided around the gravure roller. Chamber A method of applying a liquid in a manner in which it is applied to a cavity. After the application of the adhesive, the polarizing film and the film to be bonded to the polarizing film are bonded by being sandwiched by a nip roll or the like.

Further, in order to improve adhesion, the electrode coating film, the transparent protective film, and/or the adhesive-coated surface of the biaxial retardation film may be subjected to plasma treatment, corona treatment, ultraviolet irradiation treatment, or flame treatment. Surface treatment such as saponification treatment. The saponification treatment may, for example, be a method of immersing in an aqueous alkaline solution such as sodium hydroxide or potassium hydroxide.

On both surfaces of the polarizing film, a transparent protective film and a biaxial retardation film are laminated via an adhesive layer, and then a water-based adhesive is used, and heat treatment is applied to dry the film. The heat treatment, for example, by blowing hot air, is usually in the range of 40 to 100 ° C, more preferably 60 to 100 ° C. Moreover, the drying time is usually from 20 to 1200 seconds.

On the other hand, in the case of using a photocurable adhesive, the thickness of the adhesive layer is usually from 0.5 to 5 μm, more preferably from 1 to 4 μm, still more preferably from 1.5 to 4 μm. When the thickness of the adhesive layer is less than 0.5 μm, if the thickness of the adhesive layer is insufficient, and the thickness of the adhesive layer exceeds 5 μm, the appearance of the polarizing plate may be poor.

(adhesive)

In the polarizing plate of the present invention, an adhesive layer can be usually provided on the surface of the biaxial retardation film. The adhesive layer can be suitably used for bonding to liquid crystal cells when the polarizing plate is applied to a liquid crystal display device. As the adhesive to be used for the adhesive layer, a conventionally known suitable adhesive can be used, and it is not particularly limited, and examples thereof include an acrylic adhesive, an amine ester adhesive, and a polyoxygen adhesive. Among them, from the viewpoints of transparency, adhesion, reliability, rework, and the like, it is preferred to use an acrylic adhesive. The adhesive layer can be provided by applying a solution containing an adhesive to a decene-based resin film by a die coater or a gravure coater, and drying the solution. Alternatively, it may be provided by transferring a pressure-sensitive adhesive layer formed on a plastic film (referred to as a separate film) subjected to release treatment to a decene-based resin film. The thickness of the adhesive layer is generally in the range of 2 to 40 μm.

(liquid crystal display device)

The polarizing plate of the present invention can be suitably applied to a liquid crystal display device. In the liquid crystal display device, the polarizing plate of the present invention is disposed on the back side of the liquid crystal panel via an adhesive layer. In this case, in the polarizing plate of the present invention, the propylene-based resin film containing the ultraviolet absorbing agent is disposed so as to be away from the liquid crystal cell, that is, to face the backlight. In such a liquid crystal display device, since the polarizing plate of the present invention is used, the durability is good and the stability of display performance is also good. In the liquid crystal display device, a portion other than the above-described features can be suitably configured as a conventional liquid crystal display device, and the liquid crystal display device can appropriately include a constituent member (light diffusing plate, backlight, etc.) which is usually provided other than the liquid crystal panel. . Furthermore, the "back side" of the liquid crystal panel refers to a liquid The "front side" of the liquid crystal panel refers to the identification side when the liquid crystal panel is mounted on the liquid crystal display device, on the backlight side when the liquid crystal display device is mounted on the liquid crystal display device.

(Example)

The invention is illustrated in more detail below by way of examples, but the invention is not limited to the examples. The measurement of the haze, the measurement of the light transmittance, and the evaluation of the durability of the polarizing plate (overflow) were carried out by the following methods.

[Measurement of haze]

The haze was measured in accordance with JIS K7136 using a haze meter HM150 manufactured by Murakami Color Research Laboratory Co., Ltd.

[Determination of light transmittance]

Using a UV/Vis spectrophotometer UV-2450 manufactured by Shimadzu Corporation, the penetration of each wavelength between 320 and 330 nm after measuring the transmittance of light per wavelength in the wavelength range of 220 to 700 nm The highest value is taken as the light transmittance between 320 and 330 nm. Similarly, the highest value among the transmittances of the respective wavelengths between the wavelengths of 310 to 350 nm is taken as the light transmittance between the wavelengths of 310 to 350 nm, and is classified according to the following criteria. The smaller the values, the more the light in each wavelength range is blocked, that is, the ultraviolet blocking performance is good.

○: light transmittance is 1% or less Δ: light transmittance exceeds 1% and is less than 2% ×: light transmittance is 2% or more

[Evaluation of durability of polarizing plate]

The polarizing plate was cut into 40 mm × 40 mm, adhered to the soda glass through an adhesive, and placed in an oven at 80 ° C in a dry state for 1500 hours. It is recognized whether or not a spillage is generated from the propylene resin film. Further, after being placed in an oven having a temperature of 60 ° C and a relative humidity of 90% for 1500 hours, it was confirmed whether or not a spillage occurred from the propylene resin film. A haze meter HM150 manufactured by Murakami Color Research Laboratory Co., Ltd. was used to measure the haze before and after the test, and it was judged based on the change rate.

○: The amount of change in haze indicated by % is 1 or less. Δ: The amount of change in haze indicated by % is less than 1 point and less than 2 points ×: The amount of change in haze indicated by % is 2 or more points.

<Example 1>

Formulated with 0.3% by weight of 2,4,6-tris(4-hexyloxy-2-hydroxy-3-methylbenzene) in a propylene-ethylene copolymer having an ethylene content of 0.4% and an MFR of 9 g/10 min. Base)-1,3,5-three (Molecular weight: 700, obtained from ADEKA (share), called "three 1") as three a compound, and 0.7% by weight of 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole (molecular weight: 447, from BASF Japan (share), called "benzotriazole 1") as a benzotriazole-based ultraviolet absorbing compound, heated to 50 mm at 275 ° C The extruder was melt-kneaded, and then extruded in a molten state from a 600 mm wide T-die, and cooled by a cooling roller adjusted to a temperature of 20 ° C to prepare a film having a thickness of 75 μm. The transparent protective film made of the propylene-based resin was measured to have a haze of 1.2%, a maximum light transmittance of 0.7% at a wavelength of 320 to 330 nm, and a light transmittance of a wavelength of 310 to 350 nm. The maximum value is 0.8%. Again, three 1. The chemical structures of benzotriazole 1 are shown below, respectively.

Then, one side of the transparent protective film made of the propylene-based resin produced above was subjected to corona treatment, and then a photocurable epoxy resin and a photocationic polymerization initiator were applied to the corona-treated surface to a thickness of 4 μm. Photocurable adhesive. On the other hand, a biaxial retardation film composed of a decene-based resin having a phase difference R ₀ of a thickness of 50 μm which is biaxially extended and having a thickness of 55 μm and a thickness retardation phase R _th of 124 nm is 124 nm. After the corona treatment was applied to one surface, the same photocurable adhesive having the thickness of 4 μm as described above was applied to the corona-treated surface. Then, the adhesive layer of the transparent protective film made of the propylene-based resin is bonded to the surface of one side of the polarizing film, and the second layer of the decene-based resin is bonded to the other surface. The adhesive layer of the axial retardation film, at 100 mm A pair of clamping rollers are pinched. Then, from the side of the transparent protective film made of the decene-based resin, ultraviolet rays are irradiated to cure the adhesive layers of both, and a polarizing plate is produced. The durability of the polarizing plate thus obtained was evaluated by the method described above, and the amount of change in haze at 1500 hours under dry conditions of 80 ° C was 0.0 points, and the temperature was 60 ° C and the relative humidity was 90% under conditions of 1500 hours. The degree of change is 0.3 points.

<Example 2>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.4% by weight and the amount of the benzotriazole 1 was changed to 0.6% by weight. The transparent protective film made of a propylene resin has a haze of 1.0%, a maximum light transmittance of 0.4% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.5%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.1. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.4 points.

<Example 3>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.5% by weight and the amount of the benzotriazole 1 was changed to 0.5% by weight. The transparent protective film made of a propylene resin has a haze of 0.8%, a maximum light transmittance of 0.2% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.3%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.1. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.7 points.

<Example 4>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the mixture was changed to 0.6% by weight and the amount of the benzotriazole 1 was changed to 0.4% by weight. The transparent protective film made of a propylene resin has a haze of 0.6%, a maximum light transmittance of 0.1% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.2%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under dry conditions of 80 ° C was 0.3. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.3 points.

<Example 5>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the mixture was changed to 0.7% by weight and the amount of the benzotriazole 1 was changed to 0.3% by weight. The transparent protective film made of a propylene resin has a haze of 0.7%, a maximum light transmittance of 0.1% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.1%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.2. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.3 points.

<Example 6>

In addition to three A transparent protective film made of a propylene resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.8% by weight and the amount of the benzotriazole 1 was changed to 0.2% by weight. The transparent protective film made of a propylene resin has a haze of 0.6%, a maximum light transmittance of 0.0% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.1%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under dry conditions of 80 ° C was 0.4. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.6 points.

<Example 7>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.9% by weight and the amount of the benzotriazole 1 was changed to 0.1% by weight. The transparent protective film made of a propylene resin has a haze of 0.6%, a maximum light transmittance of 0.0% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.1%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.1. The amount of change in haze at 1500 hours under the conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.9 points.

<Example 8>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.5% by weight, and the benzotriazole-based ultraviolet absorbing compound was not blended. The transparent protective film made of a propylene resin has a haze of 0.1%, a maximum light transmittance of 0.9% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 2.0%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.0 points. The amount of change in haze at 1500 hours under the conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.2 points.

<Example 9>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.6% by weight, and the benzotriazole-based ultraviolet absorbing compound was not blended. The transparent protective film made of a propylene resin has a haze of 0.1%, a maximum light transmittance of 0.1% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.4%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.1. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.4 points.

<Comparative Example 1>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the mixture was changed to 0.1% by weight and the amount of the benzotriazole 1 was changed to 0.9% by weight. The transparent protective film made of a propylene resin has a haze of 1.2%, a maximum light transmittance of 38.2% between 320 and 330 nm, and a maximum light transmittance of between 310 and 350 nm. The value is 42.2%.

A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.1. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.7 points. In the polarizing plate, the maximum light transmittance between the wavelengths of 320 and 330 nm is 38.2%, which cannot be used because the alignment of the light-aligning liquid crystal cells is disturbed.

<Comparative Example 2>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.2% by weight and the amount of the benzotriazole 1 was changed to 0.8% by weight. The transparent protective film made of a propylene resin has a haze of 1.0%, a maximum light transmittance of 1.4% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 1.4%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.0 points. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.3 points. In the polarizing plate, the maximum light transmittance between the wavelengths of 320 and 330 nm is 1.4%, which is unusable because the alignment of the light-aligning liquid crystal cells is disturbed.

<Comparative Example 3>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 0.35% by weight, and the benzotriazole-based ultraviolet absorbing compound was not blended. The transparent protective film made of a propylene resin has a haze of 0.1%, a maximum light transmittance of 5.1% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.7%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.2. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 0.4 points. In the polarizing plate, the maximum light transmittance between the wavelengths of 320 and 330 nm is 5.1%, which is unusable because the alignment of the light-aligning liquid crystal cells is disturbed.

<Comparative Example 4>

In addition to three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the amount of the compound was changed to 1.00% by weight and the benzotriazole-based ultraviolet absorbing compound was not blended. The transparent protective film made of a propylene resin has a haze of 0.1%, a maximum light transmittance of 0.0% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.1%. A polarizing plate was produced in the same manner as in Example 1 except that the propylene-based resin film obtained here was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.2 points, and the temperature was 60 ° C and relative humidity. The change in haze at 1500 hours under 90% conditions was 2.8 points. The polarizing plate was overflowed at 60 ° C for 90% for 1500 hours and could not be used.

<Comparative Example 5>

In addition to formulating 0.30% by weight of 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetra) as shown in the following chemical structure Methyl butyl phenol] (molecular weight: 664, obtained from ADEKA (share), called "benzotriazole 2"), as a benzotriazole-based ultraviolet absorber, not formulated with three A transparent protective film made of a propylene resin was produced in the same manner as in Example 1 except for the compound. The transparent protective film made of a propylene resin has a haze of 2.1%, a maximum light transmittance of 15.5% between 320 and 330 nm, and a maximum light transmittance of between 310 and 350 nm. The value is 15.5%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 1.1 points. The amount of change in haze at 1500 hours under conditions of a temperature of 60 ° C and a relative humidity of 90% was 1.1 points. In the polarizing plate, the maximum light transmittance between the wavelengths of 320 to 330 nm is 15.5%, which cannot be used because the alignment of the light-aligning liquid crystal cells is disturbed.

<Comparative Example 6>

A transparent protective film made of a propylene-based resin was produced in the same manner as in Comparative Example 5 except that the amount of the benzotriazole 2 was 1.00% by weight. The transparent protective film made of a propylene resin has a haze of 1.1%, a maximum light transmittance of 0.5% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 0.5%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 21.5 points. The amount of change in haze at 1500 hours under the conditions of a temperature of 60 ° C and a relative humidity of 90% was 13.5 points. The polarizing plate was not used because it was overflowed under vacuum conditions of 80 ° C for 1500 hours and 60 ° C for 90 minutes and 1500 hours.

<Comparative Example 7>

In addition to formulating 1.00% by weight of 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3, as shown by the following chemical structure, 5-three (Molecular weight: 509, obtained from CYTEC Industries, called "Three 2") as three A transparent protective film made of a propylene-based resin was produced in the same manner as in Example 1 except that the ultraviolet absorber was not blended with the benzotriazole-based ultraviolet absorbing compound. The transparent protective film made of a propylene resin has a haze of 1.0%, a maximum light transmittance of 1.2% at a wavelength of 320 to 330 nm, and a maximum light transmittance of a wavelength of 310 to 350 nm. The value is 1.2%. A polarizing plate was produced in the same manner as in Example 1 except that the transparent protective film made of a propylene-based resin obtained in the present invention was used. When the durability was evaluated, the amount of change in haze at 1500 hours under the drying condition of 80 ° C was 0.2. The amount of change in haze at 1500 hours under the conditions of a temperature of 60 ° C and a relative humidity of 90% was 8.0 points. The polarizing plate was overflowed at 60 ° C for 90% for 1500 hours and could not be used.

The compositions and evaluation results of Examples 1 to 9 and Comparative Examples 1 to 7 are shown in Table 1.

Claims (3)

A polarizing plate comprising a transparent protective film containing a propylene resin, a polarizing film in which a dichroic dye is adsorbed to a polyvinyl alcohol resin, and a biaxial retardation film sequentially laminated, wherein the propylene resin is contained Containing at least the following formula (I): (wherein R ¹ represents an alkyl group having 1 to 12 carbon atoms, and R ² represents hydrogen or an alkyl group having 1 to 8 carbon atoms) a UV absorber of a compound, the aforementioned three The content of the compound is less than 1% by weight in the propylene-based resin, and the transmittance of light having a wavelength of from 320 to 330 nm is 1% or less. The polarizing plate according to claim 1, wherein the propylene-based resin contains a ratio of 0.5 to 0.8% by weight, and only the three of the formula (I) A UV absorber of a compound. The polarizing plate according to claim 1, wherein the propylene resin contains a ratio of 0.3 to 0.9% by weight of the third formula (I) The compound and the benzotriazole-based ultraviolet absorbing compound in a ratio of 0.1 to 0.7% by weight have a light transmittance of 1% or less at a wavelength between 310 and 350 nm.