JP2010091602A - Polarizing plate and liquid crystal display device - Google Patents

Abstract

A polarizing plate using a polyethylene terephthalate film as a protective film, having excellent adhesion between the polarizing film and the polyethylene terephthalate film and excellent in productivity, and environment resistance, particularly moisture and heat resistance using the polarizing plate. An excellent liquid crystal display device is provided.
A polarizing film comprising a polyvinyl alcohol-based resin, and a stretched polyethylene terephthalate film laminated on one side of the polarizing film via a first adhesive layer, the first adhesive layer comprising: A liquid crystal display device comprising a polarizing plate comprising a cured product layer of a solventless active energy ray-curable composition containing an epoxy compound, and a liquid crystal panel using the polarizing plate.
[Selection figure] None

Description

  The present invention relates to a polarizing plate and a liquid crystal display device using the polarizing plate.

  In recent years, low-power consumption, low-voltage, light-weight and thin liquid crystal displays are rapidly spreading as information display devices such as mobile phones, personal digital assistants, computer monitors, and televisions. Furthermore, along with the development of liquid crystal technology, liquid crystal displays of various modes have been proposed, and problems that have been considered as problems of liquid crystal displays such as response speed, contrast, and viewing angle are being solved.

  On the other hand, in response to the strong market demand to make liquid crystal display devices thinner and lighter, liquid crystal panels, diffusion plates, backlight units, and drive ICs that make up liquid crystal display devices are being made thinner and smaller. . Under such circumstances, the polarizing plate, which is a member constituting the liquid crystal panel, is also required to be thinned in units of 10 μm. Therefore, a triacetyl cellulose film that is generally used as a protective film for a polarizing plate is replaced with a thinner one from a conventional film thickness of 80 μm to 120 μm.

  However, a polarizing plate using a triacetyl cellulose film as a protective film is often inferior in heat-and-moisture resistance and cold-heat shock resistance. Under such circumstances, the polarizing performance may be deteriorated or the polarizing film may be damaged.

  The reason why the polarizing plate is often inferior in heat-and-moisture resistance is that the triacetyl cellulose film, which is a constituent element, has high moisture permeability and water absorption, and that the polarizing film that is hydrophilic and the protective film are bonded. As the adhesive, a water-based adhesive is generally used. Thus, for example, Patent Document 1 discloses means for using a cyclic olefin resin film having a lower moisture permeability and water absorption rate in place of the triacetyl cellulose film. Further, for example, Patent Document 2 discloses means for reducing the moisture permeability and water absorption rate of a triacetyl cellulose film. Furthermore, for example, Patent Document 3 discloses a means for improving an adhesive.

  However, since the cyclic olefin resin is generally expensive, it is currently used for a retardation film having a higher added value and has not been used as a simple protective film. In addition, in order to reduce moisture permeability and water absorption of the triacetyl cellulose film itself, it is necessary to provide a surface treatment layer with limited means, and the versatility may be lacking. Furthermore, the means for improving the adhesive may still lack the heat-and-moisture resistance effect.

  Further, it has been studied to use a polyethylene terephthalate film having a relatively low moisture permeability and low water absorption as a protective film in place of the triacetyl cellulose film. However, the polyethylene terephthalate film has a problem in adhesion to the polarizing film as compared with the triacetyl cellulose film.

  Furthermore, with the widespread use of liquid crystal display devices, there is an increasing demand for cost reduction by the market. In response to such a request, the number of members is reduced by integrating the functions of the members constituting the liquid crystal display device, and as a result, costs are reduced and productivity is improved. For example, Patent Document 4 discloses an optical film that can integrate a diffusion plate, a light collector, a prism sheet, and the like. However, in the polarizing plate, the cost and productivity are limited by the raw material used, and it may be difficult to reduce the cost.

On the other hand, there is also a proposal to use a solvent-free adhesive for laminating a polarizing film and a protective film. For example, Patent Document 5 discloses an adhesive composed of an epoxy resin containing no aromatic ring as a main component. Thus, it is disclosed that a protective film is bonded to a polarizing film made of a polyvinyl alcohol resin.
JP-A-7-77608 JP 2007-102179 A JP-A-2005-208456 JP 2002-277613 A JP 2004-245925 A

  Then, the objective of this invention is providing the polarizing plate which is excellent in the adhesiveness of a polarizing film and a polyethylene terephthalate film, and excellent in productivity in the polarizing plate which uses a polyethylene terephthalate film as a protective film. Another object of the present invention is to provide a liquid crystal display device using the above polarizing plate, which is excellent in environmental resistance, particularly moisture and heat resistance.

  According to the present invention, a first adhesive layer comprising: a polarizing film comprising a polyvinyl alcohol-based resin; and a stretched polyethylene terephthalate film laminated on one side of the polarizing film via a first adhesive layer. Provides a polarizing plate comprising a cured product layer of a solventless active energy ray-curable composition containing an epoxy compound. The active energy ray-curable composition preferably further contains an oxetane compound.

  The polarizing plate of the present invention may include a protective film or an optical compensation film laminated via a second adhesive layer on the surface opposite to the surface on which the stretched polyethylene terephthalate film is laminated in the polarizing film. it can. The second adhesive layer is preferably composed of a cured layer of the same composition as the active energy curable composition that bonds the stretched polyethylene terephthalate film to the polarizing film.

  As described above, when the protective film or the optical compensation film is laminated, the polarizing plate of the present invention is laminated on the surface opposite to the surface on which the polarizing film in the protective film or the optical compensation film is laminated. An adhesive layer can be provided.

  Moreover, according to this invention, a polarizing plate provided with the said adhesive layer is provided with a liquid crystal display device provided with the liquid crystal panel bonded by the liquid crystal cell through the adhesive layer.

  The polarizing plate of the present invention uses a solvent-free active energy ray-curable composition containing an epoxy compound as an adhesive for the adhesiveness between a stretched polyethylene terephthalate film and a polarizing film, and a layer obtained by curing it (adhesive) Layer) is remarkably improved. Further, since the adhesive is solvent-free, the conventionally required drying step of the adhesive becomes unnecessary, and the productivity is greatly improved.

<Polarizing plate>
The polarizing plate of this invention is equipped with the polarizing film which consists of polyvinyl alcohol-type resin, and the extending | stretching polyethylene terephthalate film laminated | stacked through the 1st adhesive bond layer on the single side | surface of this polarizing film. Further, the polarizing plate of the present invention includes a protective film or an optical compensation film laminated via a second adhesive layer on the surface of the polarizing film opposite to the surface on which the stretched polyethylene terephthalate film is laminated. It may be. Hereinafter, the polarizing plate of the present invention will be specifically described.

(Polarizing film)
The polarizing film used in the present invention is usually a step of uniaxially stretching a polyvinyl alcohol resin film by a known method, a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol resin film with a dichroic dye, The polyvinyl alcohol resin film on which the dichroic dye is adsorbed is manufactured through a step of treating with a boric acid aqueous solution and a step of washing with water after the treatment with the boric acid aqueous solution.

  As the polyvinyl alcohol resin, a saponified polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers with other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

  The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. This polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal and polyvinyl acetal modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, and preferably about 1,500 to 5,000.

  What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of a polarizing film. The method for forming a polyvinyl alcohol-based resin is not particularly limited, and can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film is not particularly limited, but is, for example, about 10 μm to 150 μm.

  Uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing the dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Moreover, you may uniaxially stretch in these several steps.

  In uniaxial stretching, it may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a hot roll. The uniaxial stretching may be dry stretching in which stretching is performed in the atmosphere, or may be wet stretching in which stretching is performed in a state where a solvent is used and the polyvinyl alcohol-based resin film is swollen. The draw ratio is usually about 3 to 8 times.

  As a method of dyeing the polyvinyl alcohol resin film with the dichroic dye, for example, a method of immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye is employed. Specifically, iodine or a dichroic dye is used as the dichroic dye. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.

  When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually about 0.01 to 1 part by weight per 100 parts by weight of water. The content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ° C. Moreover, the immersion time (dyeing time) in this aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution is usually about 1 × 10 ⁻⁴ to 10 parts by weight and preferably about 1 × 10 ⁻³ to 1 part by weight per 100 parts by weight of water. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The temperature of the aqueous dichroic dye solution used for dyeing is usually about 20 to 80 ° C. Moreover, the immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

  The boric acid treatment after dyeing with a dichroic dye can usually be performed by immersing the dyed polyvinyl alcohol resin film in a boric acid-containing aqueous solution.

  The amount of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by weight and preferably 5 to 12 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight and preferably about 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C or higher, preferably 50 to 85 ° C, and more preferably 60 to 80 ° C.

  The polyvinyl alcohol resin film after the boric acid treatment is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually about 5 to 40 ° C. Further, the immersion time is usually about 1 to 120 seconds.

  After washing with water, a drying process is performed to obtain a polarizing film. The drying treatment can be performed using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100 ° C, and preferably 50 to 80 ° C. The time for the drying treatment is usually about 60 to 600 seconds, and preferably 120 to 600 seconds.

  By the drying treatment, the moisture content of the polarizing film is reduced to a practical level. The water content is usually 5 to 20% by weight, preferably 8 to 15% by weight. When the moisture content is less than 5% by weight, the flexibility of the polarizing film is lost, and the polarizing film may be damaged or broken after drying. Moreover, when a moisture content exceeds 20 weight%, the thermal stability of a polarizing film may be inferior.

  The thickness of the polarizing film thus obtained can usually be about 5 to 40 μm.

(Stretched polyethylene terephthalate film)
The stretched polyethylene terephthalate film used in the present invention is formed by melt-extrusion of one or more polyethylene terephthalate resins, one or more uniaxially stretched films formed by transverse stretching, or longitudinally stretched after film formation, One or more biaxially stretched films formed by transverse stretching.

  The polyethylene terephthalate resin means a resin in which 80 mol% or more of repeating units are composed of ethylene terephthalate, and may contain other dicarboxylic acid components and diol components. Examples of other dicarboxylic acid components include, but are not limited to, isophthalic acid, p-β-oxyethoxybenzoic acid, 4,4′-dicarboxydiphenyl, 4,4′-dicarboxybenzophenone, bis (4-Carboxyphenyl) ethane, adipic acid, sebacic acid, 1,4-dicarboxycyclohexane and the like.

  Other diol components are not particularly limited, but propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, ethylene oxide adduct of bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol Etc.

  These other dicarboxylic acid components and other diol components can be used in combination of two or more if necessary. Moreover, oxycarboxylic acids, such as p-oxybenzoic acid, can also be used together. Further, as other copolymerization component, a dicarboxylic acid component containing a small amount of an amide bond, a urethane bond, an ether bond, a carbonate bond, or the like, or a diol component may be used.

  Polyethylene terephthalate resin can be produced by direct polycondensation of terephthalic acid and ethylene glycol (and other dicarboxylic acids or other diols as required), dialkyl esters of terephthalic acid and ethylene glycol (and if necessary) A transesterification reaction with a dialkyl ester of another dicarboxylic acid or other diol), and a polycondensation, and an ethylene glycol ester of terephthalic acid (and other dicarboxylic acids as required) A method of polycondensation of other diol esters) is employed.

  For each polymerization reaction, a polymerization catalyst composed of an antimony, titanium, germanium, or aluminum compound, or a polymerization catalyst composed of the above composite compound can be used.

  The polymerization reaction conditions may be appropriately selected according to the monomer, catalyst, reaction apparatus, and desired resin physical properties to be used, and are not particularly limited. For example, the reaction temperature is usually about 150 ° C. to The temperature is about 300 ° C, preferably about 200 ° C to about 300 ° C, more preferably about 260 ° C to about 300 ° C. The pressure is usually from atmospheric pressure to about 2.7 Pa, and it is preferable that the pressure is on the reduced pressure side in the latter half of the reaction.

  The polymerization reaction proceeds by devolatilization of the elimination reaction product such as diol, alkyl compound or water by stirring under such high temperature and high vacuum conditions.

  In addition, the polymerization apparatus may be completed with a single reaction vessel, or may be a combination of a plurality of reaction vessels. In this case, usually, the reactant is polymerized while being transferred between the reaction vessels according to the degree of polymerization. Further, a method in which a horizontal reaction apparatus is provided in the latter half of the polymerization and devolatilized while heating and kneading can be employed.

  After the polymerization is completed, the resin is extracted from a reaction vessel or a horizontal reactor in a molten state, and then cooled and crushed by a cooling drum, a cooling belt, or the like, or introduced into an extruder to form a string. It is obtained in the form of pellets which are cut after being extruded.

  Furthermore, solid phase polymerization can be performed as necessary to improve the molecular weight or reduce the low molecular weight components. Examples of the low molecular weight component that can be contained in the polyethylene terephthalate resin include a cyclic trimer component, and the content of such a cyclic trimer component in the resin is preferably 5000 ppm or less, and 3000 ppm or less. Is more preferable. If the cyclic trimer component exceeds 5000 ppm, the optical properties of the film may be adversely affected.

  The molecular weight of the polyethylene terephthalate resin is usually 0.45 to 1.0 dL when the resin is dissolved in a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio) and expressed in terms of intrinsic viscosity measured at 30 ° C. / G, preferably 0.50 to 1.0 dL / g, more preferably 0.52 to 0.80 dL / g. When the intrinsic viscosity is less than 0.45 dL / g, the productivity at the time of film production may be lowered, or the mechanical strength of the film may be lowered. Moreover, the thing whose intrinsic viscosity exceeds 1.0 dL / g may be inferior to the melt-extrusion stability of the polymer in film manufacture.

  Moreover, the polyethylene terephthalate resin can contain an additive as necessary. Examples of the additive include a lubricant, an antiblocking agent, a heat stabilizer, an antioxidant, an antistatic agent, a light resistance agent, and an impact resistance improving agent. The addition amount is preferably kept in a range that does not adversely affect the optical properties.

  Polyethylene terephthalate-based resins are usually used in the form of pellets granulated by an extruder for blending such additives and for film formation described later. The size and shape of the pellet are not particularly limited, but are usually cylindrical, spherical, or flat spherical with a height and diameter of 5 mm or less.

  The polyethylene terephthalate-based resin thus obtained can be made into a transparent and homogeneous polyethylene terephthalate film having high mechanical strength by forming into a film and stretching. The manufacturing method is not particularly limited, but for example, the method described below is adopted.

  First, dried pellets made of polyethylene terephthalate resin are supplied to a melt extrusion apparatus and heated to a melting point or higher to melt. Next, the melted resin is extruded from a die and rapidly cooled and solidified on the rotary cooling drum so that the temperature is equal to or lower than the glass transition temperature to obtain a substantially amorphous unstretched film. The melting temperature is determined according to the melting point of the polyethylene terephthalate resin to be used and the extruder, and is not particularly limited, but is usually 250 to 350 ° C.

  In order to improve the flatness of the film, it is preferable to improve the adhesion between the film and the rotary cooling drum, and an electrostatic application adhesion method or a liquid application adhesion method is preferably employed. In the electrostatic application adhesion method, a linear electrode is usually stretched in the direction perpendicular to the film flow on the upper surface side of the film, and a static voltage is applied to the film by applying a DC voltage of about 5 to 10 kV to the electrode. This is a method for improving the adhesion between the rotary cooling drum and the film. In addition, the liquid application adhesion method improves the adhesion between the rotating cooling drum and the film by uniformly applying the liquid to the entire surface of the rotating cooling drum or a part of it (for example, only the portion that contacts both ends of the film). It is a method to make it. You may use both together as needed.

  The polyethylene terephthalate resin to be used may be mixed with two or more kinds of resins having different resin structures and compositions as necessary. For example, it is possible to use a mixture of pellets containing a particulate filler, an ultraviolet absorber, or an antistatic agent as an antiblocking agent, and non-compounded pellets.

  Moreover, you may make the lamination | stacking number of the film to extrude into 2 or more layers as needed. For example, a pellet containing a granular filler as an antiblocking agent and a non-compounded pellet are prepared and supplied to the same die from different extruders, consisting of two types and three layers of “filler blend / no blend / filler blend”. For example, extruding a film.

  The unstretched film is usually first stretched in the extrusion direction at a temperature equal to or higher than the glass transition temperature. The stretching temperature is usually 70 to 150 ° C, preferably 80 to 130 ° C, and more preferably 90 to 120 ° C. Moreover, the draw ratio is 1.1 to 6 times normally, and 2 to 5.5 times is preferable. This is because when the draw ratio is less than 1.1 times, the mechanical strength of the stretched polyethylene terephthalate film tends to be insufficient. Moreover, when it exceeds 6 times, the intensity | strength of a horizontal direction may be insufficient for practical use. This stretching can be completed once or divided into a plurality of times as necessary. Usually, even when stretching is performed a plurality of times, the total stretching ratio is preferably within the above range.

  The longitudinally stretched film thus obtained can then be heat treated. Then, if necessary, relaxation treatment can be performed. This heat treatment temperature is usually 150 to 250 ° C, preferably 180 to 245 ° C, more preferably 200 to 230 ° C. The heat treatment time is usually 1 to 600 seconds, preferably 1 to 300 seconds, and more preferably 1 to 60 seconds.

  The temperature of the relaxation treatment is usually 90 to 200 ° C, preferably 120 to 180 ° C. Further, the relaxation amount is usually 0.1 to 20%, preferably 2 to 5%. More preferably, the temperature and amount of relaxation treatment are set such that the heat shrinkage rate at 150 ° C. of the polyethylene terephthalate film after the relaxation treatment is 2% or less.

  When obtaining a uniaxially stretched film and a biaxially stretched film, the film is usually stretched transversely by a tenter after the longitudinal stretching process or after a heat treatment or a relaxation process as necessary. This stretching temperature is usually 70 to 150 ° C, preferably 80 to 130 ° C, and more preferably 90 to 120 ° C. Moreover, a draw ratio is 1.1-6 times normally, and it is preferable that it is 2-5.5 times. When the draw ratio in the transverse drawing is less than 1.1 times, film strength improvement due to orientation may be insufficient. Moreover, the draw ratio exceeding 6 times is not realistic in manufacturing technology.

  Thereafter, heat treatment and relaxation treatment as necessary can be performed. The heat treatment temperature is usually 150 to 250 ° C, preferably 180 to 245 ° C, and more preferably 200 to 230 ° C. The heat treatment time is usually 1 to 600 seconds, preferably 1 to 300 seconds, and more preferably 1 to 60 seconds.

  The temperature of the relaxation treatment is usually 100 to 230 ° C, preferably 110 to 210 ° C, more preferably 120 to 180 ° C. Moreover, the relaxation amount is usually 0.1 to 20%, preferably 1 to 10%, more preferably 2 to 5%. The temperature and amount of relaxation treatment are preferably set such that the amount of relaxation and the temperature during relaxation treatment are such that the heat shrinkage rate at 150 ° C. of the polyethylene terephthalate film after relaxation treatment is 2% or less.

  In both the uniaxial stretching and biaxial stretching treatments, if the stretching treatment temperature exceeds 250 ° C., the optical performance may deteriorate due to thermal degradation of the resin or excessive crystallization. On the other hand, when the stretching treatment temperature is less than 70 ° C., excessive stress may be applied to stretching, or the film may solidify and stretching itself may be impossible.

  In the uniaxial stretching and biaxial stretching treatments, after transverse stretching, heat treatment can be performed again or stretching treatment can be performed in order to relieve distortion of the orientation main axis as represented by bowing. . The maximum value of the strain with respect to the stretching direction of the main axis of orientation due to bowing is usually within 45 °, but is preferably relaxed within 30 °, more preferably within 15 °. When the maximum value of the distortion of the orientation main axis exceeds 45 °, when the polarizing plate is formed in a later process and is made into a single sheet, non-uniform optical characteristics may occur between the single sheets.

  In addition, a extending | stretching direction here means the direction with a large draw ratio in longitudinal stretch or horizontal stretch. In the biaxial stretching of a polyethylene terephthalate film, the transverse stretching ratio is usually slightly larger than the longitudinal stretching ratio. In this case, the stretching direction refers to a direction perpendicular to the longitudinal direction of the film. Moreover, in uniaxial stretching, since it is normally stretched in the transverse direction as described above, in this case, the stretching direction is the direction perpendicular to the longitudinal direction.

  In addition, the orientation main axis here refers to a molecular orientation direction at an arbitrary point on the stretched polyethylene terephthalate film. Moreover, the distortion with respect to the extending | stretching direction of an orientation main axis means the angle difference of an orientation main axis | shaft and an extending direction. Further, the maximum value is the maximum value in the direction perpendicular to the long direction.

  The orientation main axis can be measured using, for example, a retardation film / optical material inspection apparatus RETS (manufactured by Otsuka Electronics Co., Ltd.) or a molecular orientation meter MOA (manufactured by Oji Scientific Instruments Co., Ltd.).

  When the stretched polyethylene terephthalate film used in the present invention is used on the viewing side of the polarizing plate, it is preferable that antiglare property (haze) is imparted. The method for imparting anti-glare properties is not particularly limited, but, for example, according to the method for mixing inorganic fine particles or organic fine particles into the raw material resin to form a film, the method for producing the multilayer film, A method of forming a stretched film from an unstretched film having a layer mixed with inorganic fine particles or organic fine particles on one side, or a coating liquid obtained by mixing inorganic fine particles or organic fine particles with a curable binder resin on one side of a stretched polyethylene terephthalate film For example, a method of providing an antiglare layer by curing the binder resin is employed.

  The inorganic fine particles for imparting antiglare properties are not particularly limited. For example, silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate , And calcium phosphate. Further, the organic fine particles are not particularly limited. For example, crosslinked polyacrylic acid particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles, and polyimide are used. Particles and the like.

  It is preferable that the haze value of the stretched polyethylene terephthalate film provided with the antiglare property thus obtained is in the range of 6 to 45%. If the haze value of the stretched polyethylene terephthalate film imparted with antiglare properties is less than 6%, a sufficient antiglare effect may not appear. On the other hand, if it exceeds 45%, the screen of the liquid crystal display device using this film may be whitened, resulting in a decrease in image quality.

  On the stretched polyethylene terephthalate film imparted with the antiglare property, functional layers such as a conductive layer, a hard coat layer, and a low reflection layer can be further laminated. Moreover, the resin composition which has either of these functions can also be selected as a resin composition which comprises the said glare-proof layer.

  On the other hand, when the stretched polyethylene terephthalate film is used on the backlight side of the polarizing plate, the antiglare property may not be given. In this case, the haze value is usually less than 6%. However, even if the antiglare property is not imparted, the functional layer can be laminated.

  The haze value can be measured using a haze / transmittance meter HM-150 (manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K 7136. In measuring the haze value, in order to prevent warping of the film, for example, a measurement sample in which the film surface is bonded to a glass substrate using an optically transparent adhesive so that the antiglare property-imparting surface becomes the surface. Is preferably used.

  In the stretched polyethylene terephthalate film used in the present invention, a functional layer other than the antiglare layer can be laminated on one side or both sides as long as the effects of the present invention are not hindered. Examples of the laminated functional layer include a conductive layer, a hard coat layer, a smoothing layer, an easy-sliding layer, an anti-blocking layer, and an easy-adhesion layer. Especially, since this stretched polyethylene terephthalate film is laminated | stacked through a polarizing film and an adhesive bond layer, it is preferable that the easily bonding layer is laminated | stacked.

  The component constituting the easy-adhesion layer is not particularly limited. For example, a polyester resin, a urethane resin, or an acrylic resin having a polar group in the skeleton and a relatively low molecular weight and a low glass transition temperature. Examples thereof include resins. Moreover, a crosslinking agent, an organic or inorganic filler, a surfactant, a lubricant and the like can be contained as necessary.

  The method of forming the functional layer into a stretched polyethylene terephthalate film is not particularly limited, but for example, a method of forming a film after all stretching steps have been completed, a step of stretching a polyethylene terephthalate resin, For example, a method of forming between the longitudinal stretching and the lateral stretching process, a method of forming immediately before or after bonding to the polarizing film, and the like are employed. Among these, from the viewpoint of productivity, a method in which a polyethylene terephthalate-based resin is formed after being longitudinally stretched and then stretched laterally is preferably employed.

  The stretched polyethylene terephthalate film thus obtained can be easily obtained as a commercial product. For example, “Diafoil”, “Hostafan”, “Fusion” (above, manufactured by Mitsubishi Plastics, Inc.) ), "Teijin Tetron Film", "Melinex", "Mylar", "Teflex" (Teijin DuPont Films Ltd.), "Toyobo Ester Film", "Toyobo Espet Film", "Cosmo Shine" “Chrisper” (manufactured by Toyobo Co., Ltd.), “Lumirror” (manufactured by Toray Film Processing Co., Ltd.), “Embron”, “Embret” (manufactured by Unitika Ltd.), “Skyroll” (SKC) Co., Ltd.), "Cofil" (manufactured by Kogo Co., Ltd.), "Zuitsu Polyester Film" (Co. Through, Ltd.), and "Taiko polyester film" (manufactured by Futamura Chemical Co., Ltd.), and the like. Among these, from the viewpoints of productivity and inexpensiveness, a biaxially stretched product is preferably used in the present invention.

(First adhesive layer)
The 1st adhesive bond layer with which the polarizing plate of this invention is provided is a layer which bears adhesion | attachment with a polarizing film and a stretched polyethylene terephthalate film, and the hardened | cured material layer of the solventless active energy ray-curable composition containing an epoxy compound It consists of By using a solvent-free active energy ray-curable composition containing an epoxy compound, it becomes possible to improve the adhesion between the polarizing film and the stretched polyethylene terephthalate film, and the process of drying the adhesive is unnecessary. Therefore, productivity can be improved.

  The epoxy compound contained in the active energy ray-curable composition is not particularly limited. For example, a glycidyl etherified product of an aromatic compound and a chain compound having a hydroxyl group; a compound having an amino group; And epoxidized compounds of chain compounds having a C—C double bond. By using these epoxy compounds, it becomes possible to improve the adhesion between the polarizing film and the stretched polyethylene terephthalate film.

  The glycidyl etherified product of an aromatic compound and a chain compound having a hydroxyl group is obtained by addition condensation of a compound such as epichlorohydrin to the hydroxyl group under alkaline conditions. Examples thereof include bisphenol type epoxy resins, polyaromatic ring type epoxy resins and alkylene glycol type epoxy resins.

  Examples of the bisphenol type epoxy resin include glycidyl etherified products of bisphenol A and oligomers thereof, glycidyl etherified products of bisphenol F and oligomers thereof, and 3,3 ′, 5,5′-methyl-4,4′-biphenol. Glycidyl etherified products and oligomers thereof.

  Examples of the polyaromatic epoxy resin include glycidyl etherified products of phenol novolac resins, glycidyl etherified products of cresol novolac resins, glycidyl etherified products of phenol aralkyl resins, glycidyl etherified products of naphthol aralkyl resins, and phenol dicyclopentadiene. Examples thereof include glycidyl etherified products of resins. Furthermore, a glycidyl etherified product of trihydroxyphenylmethane and an oligomer thereof, and a glycidyl etherified product of trisphenol PA and an oligomer thereof are also included.

  The glycidyl aminated product of a compound having an amino group is obtained by addition condensation of a compound such as epichlorohydrin to the amino group under basic conditions. The compound having an amino group may have a hydroxyl group at the same time. For example, glycidyl amination product of 1,3-phenylenediamine and oligomer thereof, glycidyl amination product and oligomer of 1,4-phenylenediamine, glycidyl amination and glycidyl etherification product of 3-aminophenol and oligomer thereof And glycidyl amination and glycidyl etherification products of 4-aminophenol and oligomers thereof.

  An epoxidized product of a chain compound having a CC double bond is an epoxidation of a CC compound of a chain compound having a CC double bond under basic conditions using a peroxide. It is obtained by making it.

  The chain compound having a C—C double bond is not particularly limited, and examples thereof include butadiene, isoprene, pentadiene, and hexadiene. Terpenes having a double bond are also used. For example, linacole etc. are mentioned as an acyclic monoterpene. Examples of the peroxide include hydrogen peroxide, peracetic acid, and t-butyl hydroperoxide.

  A compound having a structure obtained by dimerizing an epoxidized product of a chain compound having a C—C double bond obtained as described above via an appropriate functional group may also be used. The bond structure composed of the functional group is not particularly limited, and examples thereof include an ester bond, an ether bond, and a bond by an alkyl group. The dimerized structure of the epoxidized product may have a plurality of these bonds.

  In addition, these epoxy compounds and oligomers thereof may be used alone or in combination of two or more.

  Such epoxy compounds and oligomers thereof can be easily obtained from commercial products. For example, “Epicoat” (manufactured by Japan Epoxy Resin Co., Ltd.), “Epicron” (DIC stock) “Epototo” (manufactured by Toto Kasei Co., Ltd.), “Adeka Resin” (manufactured by ADEKA), “Epolide”, “Epofriend”, “EHPE” (above, Daicel Chemical Industries, Ltd.), and “ Tepic "(manufactured by Nissan Chemical Industries, Ltd.).

  The epoxy equivalent of the epoxy compound used in the present invention is usually 30 to 2000 g / eq, preferably 50 to 1500 g / eq, and more preferably 70 to 1000 g / eq. When the epoxy equivalent is less than 30 g / eq, the flexibility of the first adhesive layer may be lowered or the adhesive strength may be lowered. On the other hand, if it exceeds 2000 g / eq, the curing rate may decrease, or the rigidity and strength required for the cured adhesive layer may be insufficient. This epoxy equivalent is a value measured according to JIS K 7236 (ISO 3001).

The active energy ray-curable composition that forms the first adhesive layer preferably further contains an oxetane compound. By adding the oxetane compound, the curing rate of the active energy ray-curable composition can be improved. The oxetane compound is not particularly limited. Also, the production method is not particularly limited. For example, a method in which a hydroxyl group on one side of a 1,3-diol derivative compound is halogenated or tosylated, and then a cyclization reaction is carried out by elimination reaction under basic conditions. A method in which a cyclization reaction is carried out by de-CO ₂ reaction through a cyclic carbonate obtained by the reaction of a 1,3-diol derivative compound and an alkyl carbonate; by a photodimerization reaction between a compound having a carbonyl group and a vinyl compound; A method of performing a cyclization reaction; and a method of inserting a methylene group into an epoxy ring using an ylide compound are employed. Above all, through the cyclic carbonate obtained by the reaction of trimethylolpropane or its derivatives with alkyl carbonate, a method for performing cyclization reaction by its de-CO ₂ reaction is preferably employed. Further, a method in which 2,2-bis (chloromethyl) propan-1-ol is subjected to a dehydration reaction under basic conditions is also preferably employed.

  Oxetane compounds thus obtained, for example 3-ethyl-3-hydroxymethyloxetane obtained from trimethylolpropane and alkyl carbonate, and 3-ethyl-3 obtained from 2,2-bis (chloromethyl) propan-1-ol. -Chloromethyloxetane can also be used as a precursor for preparing derivative compounds thereof.

  Specific examples of oxetane compounds that can be used in the present invention include 1,4-bis {[(3-ethyloxetane-3-yl) methoxy] methyl} benzene, 3-ethyl-3- (2- Ethylhexyloxymethyl) oxetane, bis (3-ethyl-3-oxetanylmethyl) ether, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3- (cyclohexyloxymethyl) oxetane, phenol novolac oxetane, and 1,3-bis [(3-ethyloxetane-3-yl) methoxy] benzene and the like.

  Such oxetane compounds may be used alone or in admixture of two or more when blended with an epoxy compound.

  Such oxetane compounds can be easily obtained as commercial products. For example, “Aron Oxetane” (manufactured by Toagosei Co., Ltd.) and “ETERRNACOLL” (manufactured by Ube Industries, Ltd.) are available under the trade names. Etc.

  The oxetane equivalent of the oxetane compound used in the present invention is usually 30 to 2000 g / eq, preferably 50 to 1500 g / eq, and more preferably 70 to 1000 g / eq. When the oxetane equivalent is less than 30 g / eq, the flexibility of the first adhesive layer may be reduced or the adhesive strength may be reduced. On the other hand, if it exceeds 2000 g / eq, the curing rate may decrease, or the rigidity and strength required for the cured adhesive layer may be insufficient. The oxetane equivalent is a value for calculating a theoretical value from the molecular structure.

  The compounding ratio of the epoxy compound and the oxetane compound used in the present invention is preferably 0 to 900 parts by weight of the oxetane compound with respect to 100 parts by weight of the epoxy compound. Moreover, 25-400 weight part is more preferable, and 40-250 weight part is further more preferable. When 25 parts by weight or more of the oxetane compound is blended with 100 parts by weight of the epoxy compound, the effect of improving the curing rate is easily obtained. On the other hand, when 900 parts by weight or more of the oxetane compound is blended with 100 parts by weight of the epoxy compound, the strength and heat resistance of the cured adhesive layer may be inferior.

  The epoxy compound and the oxetane compound are not diluted with an organic solvent or the like. In addition, even in a small amount of components such as a photopolymerization initiator and a sensitizer constituting the active energy ray-curable composition which is an adhesive composition described later, the organic solvent is removed rather than the one dissolved in the organic solvent. It is preferred to use a dried powder or liquid of the compound alone.

  The viscosity at 25 ° C. of the active energy ray-curable composition before curing is not particularly limited as long as it is a viscosity that can be applied to the film by an appropriate method, but is preferably in the range of 10 to 30000 mPa · s, 50 A range of ˜6000 mPa · s is more preferable. If the viscosity of the active energy ray-curable composition is less than 10 mPa · s, the apparatus that can be applied is limited, and even if it can be applied, a uniform coating without unevenness may not be obtained. Moreover, when it exceeds 30000 mPa · s, since it is difficult to flow, the apparatus which can be similarly applied is limited, and a uniform coating film without unevenness may not be obtained. The viscosity of the active energy ray-curable composition is a value measured at 60 rpm after adjusting the temperature of the composition to 25 ° C. using a B-type viscometer.

  The total chlorine content contained in the active energy ray-curable composition containing the epoxy compound or epoxy compound and oxetane compound used in the present invention is preferably in the range of 0.1 ppm to 15000 ppm, and in the range of 0.5 ppm to 2000 ppm. More preferably, the range of 1.0 to 1000 ppm is even more preferable. If the total amount of chlorine contained in the active energy ray-curable composition is less than 0.1 ppm, the curing rate of the composition may be extremely slow. On the other hand, if it exceeds 15000 ppm, the coating device may corrode or the metal parts of the liquid crystal panel may corrode due to the influence of chlorine. This total chlorine amount is a value measured in accordance with JIS K 7243-3 (ISO 21627-3).

  The hue of the active energy ray-curable composition containing the epoxy compound or the epoxy compound and the oxetane compound used in the present invention is preferably 5 or less in terms of Gardner chromaticity of the active energy ray-curable composition before curing. More preferred is 1 or less. When the hue exceeds 5, the hue of the polarizing plate may be affected by the coloring of the adhesive layer.

  The active energy ray-curable composition containing an epoxy compound or an epoxy compound and an oxetane compound used in the present invention is solidified (cured) by irradiation with active energy rays, and has an adhesive force between films holding the cured product layer. It is a curable composition that gives.

  Examples of the active energy ray used include X-rays having a wavelength of 1 pm to 10 nm, ultraviolet rays having a wavelength of 10 to 400 nm, and visible rays having a wavelength of 400 to 800 nm. Among these, ultraviolet rays are preferably used in terms of ease of use, ease of adjustment of the active energy ray-curable composition and its stability, and its curing performance.

  Although the light source to be used is not particularly limited, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, having a light emission distribution at a wavelength of 400 nm or less, And metal halide lamps.

The irradiation intensity is determined by the active energy ray-curable composition and the irradiation time, and is not particularly limited. For example, the irradiation intensity in the wavelength region effective for activating the initiator is 0.1. It is preferable that it is -1000mW / cm < ² >. When the light irradiation intensity to the active energy ray-curable composition is less than 0.1 mW / cm ² , the curing reaction time becomes long, that is, it does not cure unless a long irradiation time is applied, which is disadvantageous for improving productivity. There is a case. Moreover, when it exceeds 1000 mW / cm ² , yellowing of the active energy ray-curable composition or deterioration of the polarizing film is caused by heat radiated from the lamp and heat generation during polymerization of the active energy ray-curable composition. There is.

The irradiation time is determined by the active energy ray-curable composition and the irradiation intensity and is not particularly limited. For example, the integrated light amount expressed as the product of the irradiation intensity and the irradiation time is 10 to 5 It is preferably set to be 000 mJ / cm ² . When the integrated light amount to the active energy ray-curable composition is less than 10 mJ / cm ² , the generation of active species derived from the initiator is not sufficient, and the resulting adhesive layer may be insufficiently cured. On the other hand, if it exceeds 5,000 mJ / cm ² , the irradiation time becomes very long, which may be disadvantageous for improving productivity.

  The active energy ray-curable composition containing an epoxy compound or an epoxy compound and an oxetane compound used in the present invention preferably contains a cationic polymerization initiator in order to be cured by active energy rays. 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, and electron beams, and initiates an epoxy group polymerization reaction.

  This cationic polymerization initiator is preferably provided with latency. By providing the potential, the pot life of the active energy ray-curable composition used in the present invention is prolonged, and the workability is also improved.

  The compound that generates a cation species or a Lewis acid upon irradiation with active energy rays is not particularly limited, and examples thereof include onium salts such as aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, and iron. -An allene complex etc. can be mentioned.

  Examples of the aromatic diazonium salt include benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and benzenediazonium hexafluoroborate.

  Examples of the aromatic iodonium salt include diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and di (4-nonylphenyl) iodonium hexafluorophosphate.

  Examples of the aromatic sulfonium salt include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, diphenyl [4- (phenylthio) phenyl] sulfonium hexafluoroantimonate, 4,4′-bis [diphenylsulfonio] diphenyl sulfide bishexafluorophosphate, 4,4′-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenyl sulfide bishexafluoroantimonate, 4,4′-bis [Di (β-hydroxyethoxy) phenylsulfonio] diphenyl sulfide bishexafluorophosphate, 7- [di (p-toluyl) sulfoni ] -2-Isopropylthioxanthone hexafluoroantimonate, 7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate, 4-phenylcarbonyl-4'-diphenylsulfonio-diphenyl sulfide hexa Fluorophosphate, 4- (p-tert-butylphenylcarbonyl) -4'-diphenylsulfonio-diphenyl sulfide hexafluoroantimonate, and 4- (p-tert-butylphenylcarbonyl) -4'-di (p-toluyl) ) Sulfonio-diphenyl sulfide tetrakis (pentafluorophenyl) borate and the like.

  Examples of iron-allene complexes include xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, and xylene-cyclopentadienyl iron (II)- And tris (trifluoromethylsulfonyl) methanide.

  These cationic polymerization initiators may be used alone or in combination of two or more. Among them, aromatic sulfonium salts are particularly preferably used because they have ultraviolet absorption characteristics even in a wavelength region of 300 nm or more, and therefore can provide a cured layer having excellent curability and good mechanical strength and adhesive strength. .

  The compounding quantity of a cationic polymerization initiator is 0.5-20 weight part normally with respect to a total of 100 weight part of an epoxy compound or an epoxy compound, and an oxetane compound, and 1-15 weight part is preferable. If the amount is less than 0.5 parts by weight, curing may be insufficient, and the mechanical strength and adhesive strength of the cured product layer may be reduced. On the other hand, when the amount exceeds 20 parts by weight, the ionic substance in the cured product layer is increased, so that the hygroscopic property of the cured product layer is increased, and the durability performance of the obtained polarizing plate may be lowered.

  These cationic polymerization initiators can be easily obtained from commercial products, for example, “Kayarad” (manufactured by Nippon Kayaku Co., Ltd.), “Syracure” (manufactured by Union Carbide), Photoacid generator “CPI” (manufactured by San Apro Co., Ltd.), photoacid generators “TAZ”, “BBI”, “DTS” (manufactured by Midori Chemical Co., Ltd.), “Adekaoptomer” (manufactured by ADEKA Corporation) And “RHODORSIL” (manufactured by Rhodia).

  The active energy ray-curable composition containing an epoxy compound or an epoxy compound and an oxetane compound used in the present invention can be used in combination with a photosensitizer as necessary. By using a photosensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the cured product layer can be improved.

  The photosensitizer is not particularly limited, and examples thereof include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreductive dyes. .

  Examples of the carbonyl compound include benzoin derivatives such as benzoin methyl ether, benzoin isopropyl ether, and α, α-dimethoxy-α-phenylacetophenone; anthracene compounds such as 9,10-dibutoxyanthracene; benzophenone, 2,4 Benzophenone derivatives such as -dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, and 4,4'-bis (diethylamino) benzophenone; of 2-chloroanthraquinone and 2-methylanthraquinone Anthraquinone derivatives such as; acridone derivatives such as N-methylacridone and N-butylacridone; acetophenone derivatives such as α, α-diethoxyacetophenone; And fluorenone derivatives.

  Examples of the organic sulfur compound include thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone. Other examples include benzyl compounds and uranyl compounds.

  The photosensitizers may be used alone or in combination. The photosensitizer is preferably contained in the range of 0.1 to 20 parts by weight when the active energy ray-curable composition is 100 parts by weight.

  Various additives can be blended with the active energy ray-curable composition used in the present invention as long as the effects of the present invention are not impaired. Examples of various additives include ion trapping agents, antioxidants, chain transfer agents, sensitizers, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, and antifoaming agents. It is done.

  Examples of the ion trapping agent include inorganic compounds such as powdered bismuth-based, antimony-based, magnesium-based, aluminum-based, calcium-based, titanium-based, and mixed systems thereof. Examples of the antioxidant include hindered phenol antioxidants.

  Although the method of forming the layer (adhesive layer before hardening) which consists of the active energy ray curable composition shown above on a polarizing film or a stretched polyethylene terephthalate film is not specifically limited, For example, a polarizing film Alternatively, a method of coating the composition on a stretched polyethylene terephthalate film, a method of spraying the composition, a method of pasting the composition formed in advance into a film, or the like is employed. Among them, the method of applying the composition or the method of pasting the film-like composition is preferable because of relatively high uniformity of the coating film, and the method of applying the composition is more highly productive. preferable.

  Although it does not specifically limit as a coating method, For example, various coating systems, such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater, are employ | adopted.

  The thickness of the applied adhesive layer before curing is usually 0.1 to 20 μm, preferably 0.2 to 10 μm, and more preferably 0.5 to 5 μm. If the thickness is less than 0.1 μm, the adhesion between the polarizing film and the stretched polyethylene terephthalate film due to the cured adhesive layer may be insufficient. Further, if the thickness exceeds 20 μm, the curing of the adhesive layer may not proceed sufficiently, or even if cured, the flexibility of the film may deteriorate due to the thickness, or the effect of thinning may not be obtained. .

(Protective film, optical compensation film)
The polarizing plate of the present invention may include a protective film or an optical compensation film laminated via a second adhesive layer on the surface of the polarizing film opposite to the surface on which the stretched polyethylene terephthalate film is laminated. Good.

  The protective film or the optical compensation film can be appropriately used in accordance with the purpose as long as it has an optical property as an optical film, and is not particularly limited, but examples of the protective film include triacetyl cellulose (TAC). And other transparent films such as a cellulose resin film, an olefin resin film, an acrylic resin film, a polycarbonate resin film, and a polyester resin film.

  Also, as the optical compensation film, those obtained by stretching the film mentioned as the protective film to give refractive index anisotropy, those containing an optical anisotropy imparting additive, and optical anisotropy on the surface Examples include those in which a layer is formed.

  Further, as described later, these protective films or optical compensation films can be laminated with an optical functional film or coated with an optical functional layer.

  The cellulose resin film is a film made of a part of cellulose or a completely esterified product, and examples thereof include films made of cellulose acetate ester, propionate ester, butyrate ester, and mixed esters thereof. Among these, a triacetyl cellulose film, a diacetyl cellulose film, a cellulose acetate propionate film, a cellulose acetate butyrate film, and the like are preferably used.

  Such cellulosic resin films can be easily obtained as commercial products. For example, “Fujitac TD” (manufactured by Fuji Film Co., Ltd.) and “Konica Minolta TAC Film KC” ( Konica Minolta Opto Co., Ltd.).

  The olefin resin film is a film made of a resin obtained by polymerizing a chain olefin monomer such as ethylene and propylene and a cyclic olefin monomer such as norbornene and other cyclopentadiene derivatives using a polymerization catalyst. is there.

  Examples of the olefin resin made of a chain olefin monomer include polyethylene or polypropylene resin. Among these, a polypropylene resin made of a homopolymer of propylene is preferable. Also preferred is a polypropylene resin in which a comonomer mainly composed of propylene and copolymerizable with it is usually copolymerized at a ratio of 1 to 20% by weight, preferably 3 to 10% by weight.

  When a polypropylene resin made of a propylene copolymer is used, ethylene, 1-butene, and 1-hexene are preferable as the comonomer copolymerizable with propylene. Among these, those obtained by copolymerizing ethylene at a ratio of 3 to 10% by weight are preferable because of relatively excellent transparency and stretchability. By making the copolymerization ratio of ethylene 1% by weight or more, an effect of improving transparency and stretch processability appears. On the other hand, when the ratio exceeds 20% by weight, the melting point of the resin is lowered, and the heat resistance required for the protective film and the optical compensation film may be impaired.

  Such polypropylene-based resins can be easily obtained from commercial products. For example, “Prime Polypro” (manufactured by Prime Polymer Co., Ltd.), “Novatech”, “Wintech” (above) , Manufactured by Nippon Polypro Co., Ltd.), “Sumitomo Noblen” (manufactured by Sumitomo Chemical Co., Ltd.), “Sun Aroma” (manufactured by Sun Aroma Co., Ltd.)

  An olefin resin obtained by polymerizing a cyclic olefin is generally referred to as a cyclic (poly) olefin resin, an alicyclic (poly) olefin resin, or a norbornene resin. Here, it is called a cyclic olefin resin.

  Examples of the cyclic olefin-based resin include a resin obtained by performing ring-opening metathesis polymerization from cyclopentadiene and olefins using norbornene obtained by Diels-Alder reaction or a derivative thereof as a monomer, followed by hydrogenation; dicyclopentadiene and Resins obtained by ring-opening metathesis polymerization from olefins or methacrylic acid esters using tetracyclododecene or its derivatives obtained by Diels-Alder reaction as monomers, followed by hydrogenation; norbornene, tetracyclododecene, etc. Similarly, a ring-opening metathesis copolymerization with other cyclic olefin monomers and a resin obtained by subsequent hydrogenation; and norbornene, tetracyclododecene, Derivatives of al, and resins obtained by copolymerizing by addition polymerization of aromatic compounds and the like having a vinyl group.

  Such a cyclic olefin-based resin can be easily obtained as a commercial product. For example, under the trade name, “Topas” (Topas Advanced Polymers GmbH), “Arton” (manufactured by JSR Corporation), “Zeonor”, “Zeonex” (manufactured by Nippon Zeon Co., Ltd.), “Appel” (manufactured by Mitsui Chemicals, Inc.), and the like.

  Preferable specific examples of the acrylic resin film include a film made of methyl methacrylate resin. The methyl methacrylate resin is a polymer containing 50% by weight or more of methyl methacrylate units. The content of methyl methacrylate units is preferably 70% by weight or more, and may be 100% by weight. The polymer having a methyl methacrylate unit of 100% by weight is a methyl methacrylate homopolymer obtained by polymerizing methyl methacrylate alone.

  This methyl methacrylate-based resin is usually a monofunctional monomer mainly composed of methyl methacrylate and a polyfunctional monomer used as necessary, as a radical polymerization initiator and as required. It can be obtained by polymerization in the presence of a chain transfer agent.

  The monofunctional monomer that can be copolymerized with methyl methacrylate is not particularly limited. For example, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, methacrylic acid 2 -Methacrylic acid esters other than methyl methacrylate such as ethylhexyl and 2-hydroxyethyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-acrylate Acrylic esters such as ethylhexyl and 2-hydroxyethyl acrylate; methyl 2- (hydroxymethyl) acrylate, methyl 3- (hydroxyethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate And hydroxyacrylic esters such as 2- (hydroxymethyl) butyl acrylate; unsaturated acids such as methacrylic acid and acrylic acid; halogenated styrenes such as chlorostyrene and bromostyrene; vinyltoluene and α-methylstyrene Substituted styrenes; unsaturated nitriles such as acrylonitrile and methacrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; and unsaturated imides such as phenylmaleimide and cyclohexylmaleimide it can. Such monomers may be used alone or in combination of two or more.

  The polyfunctional monomer that can be copolymerized with methyl methacrylate is not particularly limited. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Ethylene glycol such as tetraethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, and tetradecaethylene glycol (meth) acrylate, or both terminal hydroxyl groups of oligomers thereof esterified with acrylic acid or methacrylic acid ; Hydroxyl or methacrylic acid esterified at both terminal hydroxyl groups of propylene glycol or its oligomer; Neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate Lilate and hydroxyl group of dihydric alcohol such as butanediol di (meth) acrylate esterified with acrylic acid or methacrylic acid; Bisphenol A, alkylene oxide adduct of bisphenol A, or both terminal hydroxyl groups of these halogen-substituted products Esterified with acrylic acid or methacrylic acid; polyhydric alcohols such as trimethylolpropane and pentaerythritol esterified with acrylic acid or methacrylic acid, and the epoxy group of glycidyl acrylate or glycidyl methacrylate opened at the terminal hydroxyl groups Cyclic addition: Dibasic acids such as succinic acid, adipic acid, terephthalic acid, phthalic acid, halogen-substituted products thereof, and alkylene oxide adducts thereof. Those with an epoxy group of bets or glycidyl methacrylate by ring-opening addition; aryl (meth) acrylate; and diaryl compounds such as divinylbenzene, and the like. Among these, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate are preferably used.

  The methyl methacrylate resin used in the present invention may be a modified methyl methacrylate resin modified by performing a reaction between functional groups of the resin. As the reaction, for example, demethanol condensation reaction in a polymer chain between a methyl ester group of methyl acrylate and a hydroxyl group of 2- (hydroxymethyl) methyl acrylate, and a carboxyl group of acrylic acid and 2- (hydroxymethyl) ) Intrapolymer dehydration condensation reaction with hydroxyl group of methyl acrylate.

  Commercially available methyl methacrylate resins can be easily obtained. For example, “Sumipex” (manufactured by Sumitomo Chemical Co., Ltd.), “Acrypet” (manufactured by Mitsubishi Rayon Co., Ltd.), “Delpet” (manufactured by Asahi Kasei Co., Ltd.), “Parapet” (manufactured by Kuraray Co., Ltd.), “Acryviewer” (manufactured by Nippon Shokubai Co., Ltd.), and the like.

  The polycarbonate resin constituting the polycarbonate resin film is usually obtained by reacting a dihydric phenol and a carbonate precursor such as phosgene or diphenyl carbonate by an interfacial polycondensation method or a melt transesterification method. An aromatic polycarbonate resin using bisphenol A as a dihydric phenol is common. In addition, a polymer obtained by polymerizing a carbonate prepolymer by a solid phase transesterification method, a polymer obtained by subjecting a cyclic carbonate compound to ring-opening polymerization, or the like can also be used.

  The dihydric phenol is not particularly limited as long as it does not impair the performance as an optical transparent resin. For example, in addition to bisphenol A (2,2-bis (4-hydroxyphenyl) propane) , Hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis {(4-hydroxy-3,5-dimethyl) phenyl} methane, 1,1-bis (4-hydroxyphenyl) Ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 2 , 2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4 Hydroxy-3,5-dimethyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dibromo) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2- Bis (4-hydroxyphenyl) -3-methylbutane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxy) Phenyl) -4-methylpentane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4-hydroxy-3-methyl) phenyl} fluorene, 9,9-bis {(4-hydroxy) −3,5-dimethyl) phenyl} fluorene, 9,9-bis {(4-hydroxy-3,5-dibromo) phenyl} fluorene, α, α′-bis ( -Hydroxyphenyl) -o-diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -p-diisopropylbenzene, 4,4 ' -Dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether and the like can be mentioned, and these can be used alone or in admixture of two or more.

  Moreover, a monohydric phenol compound may be used in combination to adjust the molecular weight to an appropriate range or to seal the hydroxyl terminal of the polymer chain. The monohydric phenol is not particularly limited as long as it is a compound that functions as a terminal blocking agent. For example, phenol, 4-tert-butylphenol, and 1-phenyl-1- (4-hydroxyphenyl) Examples include propane.

  Further, if necessary, a compound having UV absorbability such as 2- (2-hydroxy-3-t-butyl-5- (2-carboxyethyl)) phenylbenzotriazole may be used as the end-capping agent. .

  Polycarbonate resins can be easily obtained as commercial products. For example, “Lexan” (manufactured by SABIC Innovative Plastics), “Macrolon”, “Apec” (above, Bayer MaterialScience) "Iupilon", "Novax" (Mitsubishi Engineering Plastics Co., Ltd.), "Panlite" (manufactured by Teijin Chemicals Ltd.), "Caliber" (Dow Chemical Co., Ltd.), "SD Polyca" ( Sumitomo Dow Co., Ltd.) and “Toughlon” (Idemitsu Kosan Co., Ltd.).

  As a method for molding the olefin resin, cyclic olefin resin, methyl methacrylate resin, polycarbonate resin, and the like thus obtained into a protective film, a method corresponding to the resin may be appropriately selected, and the method is particularly limited. It is not something. For example, a resin dissolved in a solvent is cast onto a metallic band or drum, and the solvent is cast by removing the solvent by drying, and the resin is heated and kneaded above its melting temperature and extruded from a die, A melt extrusion method for obtaining a film by cooling is employed. Of these, the melt extrusion method is preferably employed from the viewpoint of productivity.

  Moreover, the film which consists of the said resin which can be used as a protective film can obtain a commercial item easily, for example, if it is a polypropylene-type resin film, a brand name will be "FILMAX CPP film" (FILMAX company), respectively. ), "Santox" (manufactured by Santox Co., Ltd.), "Tosero" (manufactured by Tosero Co., Ltd.), "Toyobo Pyrene Film" (manufactured by Toyobo Co., Ltd.), "Trephan" (manufactured by Toray Film Co., Ltd.) ), “Nihon Polyace” (manufactured by Nippon Polyace Corporation), “Dazai FC” (manufactured by Futamura Chemical Co., Ltd.), and the like.

  Further, for example, in the case of a cyclic olefin-based resin film, “ZEONOR FILM” (manufactured by Optes Co., Ltd.), “ARTON FILM” (manufactured by JSR Corporation), and the like are listed under the trade names.

  Also, for example, for methyl methacrylate resin films, “Sumipex” (manufactured by Sumitomo Chemical Co., Ltd.), “Acrylite”, “Acryprene” (above, Mitsubishi Rayon Co., Ltd.), “Delagrass” ( Asahi Kasei Co., Ltd.), “Paragrass”, “Comograss” (manufactured by Kuraray Co., Ltd.), “Acryviewer” (manufactured by Nippon Shokubai Co., Ltd.), and the like.

  In addition, for example, for polycarbonate resin films, “Lexan OQ Film” (manufactured by SABIC Innovative Plastics), “Macro Hall”, “Bihole” (above, Bayer MaterialScience), “Iupilon Sheet” "(Mitsubishi Engineering Plastics Co., Ltd.)" and "Panlite Sheet" (Teijin Chemicals Co., Ltd.).

  In addition, as the polyester-based resin film used as a protective film provided via the second adhesive layer on the side opposite to the side on which the stretched polyethylene terephthalate film is laminated in the polarizing film, the stretched polyethylene terephthalate film is configured. The same kind of polyester resin (polyethylene terephthalate resin) can be used. In this case, an unstretched polyester resin film is used, and for example, the film obtained by the melt extrusion can be used as it is.

  Unstretched polyester resin films that can be used as protective films can be easily obtained as commercial products. For example, “Novaclear” (manufactured by Mitsubishi Chemical Corporation) and “Teijin A” under the trade names, respectively. -PET sheet "(manufactured by Teijin Chemicals Ltd.) and the like.

  In addition, the optical compensation film made of a cellulose resin film is not particularly limited as long as it has a refractive index characteristic suitable for the purpose. For example, the cellulose resin film mentioned above is uniaxial or biaxial. A film obtained by stretching, or a film in which a compound having a retardation adjusting function is contained in a cellulose resin film, a film in which a compound having a retardation adjusting function is applied to the surface of a cellulose resin film, and those films Further, a film obtained by further uniaxially or biaxially stretching can be mentioned.

  The optical compensation film made of a cellulose resin film can be easily obtained as a commercial product. For example, “Fujitac WV” (manufactured by Fuji Film Co., Ltd.) and “Konica Minolta TAC Film KC8UCR” are available under the trade names. (Made by Konica Minolta Opto Co., Ltd.).

  Moreover, in order to use the olefin resin film, the acrylic resin film, the polycarbonate resin film, the polyester resin film, and the like exemplified as the protective film as an optical compensation film, the unstretched film is usually stretched, This is done by giving the film refractive index anisotropy. The stretching method is selected according to the required refractive index anisotropy and is not particularly limited. Usually, however, the longitudinal uniaxial stretching, the transverse uniaxial stretching, and the longitudinal and transverse sequential biaxial stretching are performed. Is adopted.

Usually, was longitudinally uniaxially stretched film has a refractive index anisotropy of _{n x> n y = n z} . Here, n _x is the refractive index in the stretching direction of the film, n _y is a refractive index in the width direction of the film, n _z is the normal direction refractive index of the film.

Also, usually, is transverse uniaxially stretched film has a refractive index anisotropy of _{n x> n y ≒ n z} . Also, typically, it has been sequentially biaxially-oriented film has a refractive index anisotropy of _{n x> n y> n z} .

Moreover, in order to provide a desired refractive index characteristic, a heat-shrinkable film is bonded to a target film, and the film is contracted instead of or along with the stretching process. Usually, this operation is performed in order to obtain an optical compensation film having a refractive index anisotropy is n _x> n _z> n _y or _{n z> n x ≧ n y} .

  As the optical compensation film, a commercially available product can be easily obtained. For example, as an optical compensation film comprising a cyclic polyolefin resin, “ZEONOR FILM” (manufactured by Optes Co., Ltd.), “ARTON” “Film” (manufactured by JSR Corporation), “Essina retardation film” (manufactured by Sekisui Chemical Co., Ltd.), “Pure Ace ER” (manufactured by Teijin Chemicals Ltd.), and the like. Examples of the optical compensation film made of a polycarbonate-based resin include “Pure Ace WR” (manufactured by Teijin Chemicals Ltd.).

  Furthermore, an optical functional film can be laminated or an optical functional layer can be coated on the protective film or the optical compensation film laminated on the polarizing film via the second adhesive layer. Examples of the optical functional film and the functional layer include an antiglare layer, a conductive layer, a hard coat layer, and a low reflection layer.

(Second adhesive layer)
The second adhesive layer is a layer responsible for adhesion between the polarizing film and the above-described protective film or optical compensation film. Similar to the first adhesive layer, the second adhesive layer may be composed of a cured layer of a solventless active energy ray-curable composition containing an epoxy compound. Moreover, when the same composition as the active energy ray-curable composition for forming the first adhesive layer is used as the active energy ray-curable composition for forming the second adhesive layer, one kind of adhesive is used. As a result, the process becomes simple and the drying of the adhesive is not necessary, so there is no need for drying equipment after pasting the protective film or optical compensation film. Since the stretched polyethylene terephthalate film and the protective film or the optical compensation film disposed on both sides of the polarizing film can be bonded simultaneously by irradiation, there is an advantage that productivity is improved.

  In addition, as an adhesive forming the second adhesive layer, for example, a water-based adhesive used when bonding a polarizing film and a protective film made of a TAC film may be used. Examples of the adhesive component that can be a water-based adhesive include water-soluble crosslinkable epoxy resins and urethane resins.

  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. The polyamide epoxy resin obtained is mentioned.

  Such a polyamide epoxy resin is commercially available. For example, “Smileys Resin 650” and “Smileys Resin 675” (sold by Sumika Chemtex Co., Ltd.) are listed as trade names. It is done.

  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.

  Such a polyvinyl alcohol-based resin can be obtained as a commercial product. For example, for an anionic group-containing polyvinyl alcohol, “KL-318” (manufactured by Kuraray Co., Ltd.) can be given as a trade name.

  When an adhesive containing a water-soluble crosslinkable epoxy resin is used, an adhesive solution is prepared by dissolving the crosslinkable epoxy resin and other water-soluble resins such as a polyvinyl alcohol resin added as necessary in water. Configure. In this case, the water-soluble crosslinkable epoxy resin is usually used at a concentration in the range of 0.2 to 2 parts by weight per 100 parts by weight of water.

  Moreover, when mix | blending polyvinyl alcohol-type resin, the quantity is the density | concentration of the range of 1-10 weight part per 100 weight part of water, and 1-5 weight part is preferable.

  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 and becomes an emulsion.

  Such an ionomer type urethane resin can be easily obtained as a commercial product of an emulsion, and examples thereof include “Hydran AP-20” and “Hydran APX-101H” (manufactured by DIC Corporation).

  When an ionomer type urethane resin is used as an adhesive component, it is preferable to further add a crosslinking agent such as an isocyanate. 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, Examples thereof include monomers such as 6-hexamethylene diisocyanate and isophorone diisocyanate, oligomers thereof, and adducts obtained by reacting these compounds with polyols.

  Such an isocyanate-based crosslinking agent can be easily obtained as a commercial product, and examples thereof include “Hydran Assist C-1” (manufactured by DIC Corporation).

  When an aqueous adhesive containing an ionomer type urethane resin is used, the concentration of the urethane resin dispersed in water is usually 10 to 70% by weight and preferably 20 to 50% by weight from the viewpoints of viscosity and adhesiveness. .

  When mix | blending an isocyanate type crosslinking agent, the compounding quantity is 5-100 weight part of isocyanate type crosslinking agents with respect to 100 weight part of urethane resins normally.

  The polarizing plate of the present invention can be obtained by applying the water-based adhesive as described above to the adhesive surface of the protective film, the optical compensation film, or the polarizing film and bonding them together. Prior to bonding, it is also effective to increase the wettability by subjecting the surface of the protective film or the optical compensation film to easy adhesion treatment such as corona discharge treatment.

  In the case of adhesion using such an aqueous adhesive, a drying treatment is usually performed at a temperature of about 30 to 100 ° C. after lamination. Thereafter, it is preferable to perform curing for about 1 to 10 days at a temperature of about 20 to 50 ° C. in order to further increase the adhesive force.

(Adhesive layer)
The polarizing plate of the present invention can have an adhesive layer on the outer side of the protective film or the optical compensation film (the surface opposite to the surface on which the polarizing film in the protective film or the optical compensation film is laminated). Such an adhesive layer can be used for bonding with a liquid crystal cell, for example.

  The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is not particularly limited as long as it satisfies various properties (transparency, durability, reworkability, etc.) used in the optical film. For example, (meth) acrylic acid ester The glass transition temperature (Tg) is 0 ° C., which is obtained by radical polymerization of an acrylic monomer composition containing a main component and a small amount of a (meth) acrylic monomer having a functional group in the presence of a polymerization initiator. An acrylic pressure-sensitive adhesive containing the following acrylic resin and a crosslinking agent is used.

Here, the (meth) acrylic acid ester as the main component of the acrylic resin has the following formula:
CH ₂ = C (R ₁ ) COOR ₂
In the formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group, and a hydrogen atom or an aralkyl group of the alkyl group represented by R _2. The hydrogen atom may be substituted with an alkoxy group having 1 to 10 carbon atoms.

  In addition, the (meth) acrylic monomer having a functional group has a polar functional group such as a hydroxyl group, a carboxyl group, an amino group, and an epoxy group and one olefinic double bond (usually a (meth) acryloyl group) in the molecule. It is a monomer to contain.

As a specific example of the main component of the acrylic resin (meth) acrylic acid esters, for example, R ₁ is H, butyl acrylate and R ₂ are n- butyl group, R ₁ is H And ₂ -ethylhexyl acrylate in which R ₂ is a 2-ethylhexyl group. Specific examples of the (meth) acrylic monomer having a functional group include, for example, 2-hydroxyethyl (meth) acrylate having a hydroxyl group; acrylic acid having a carboxyl group. Furthermore, in the production of this acrylic resin, a small amount of monomers having a plurality of (meth) acryloyl groups in the molecule can be copolymerized, and examples thereof include 1,4-butanediol di (meth) acrylate. It is done.

  In the production of the acrylic resin, only one type of the (meth) acrylic acid ester and the (meth) acrylic monomer having a functional group may be used, or a plurality of types may be used in combination. In addition, a combination of a plurality of acrylic resins that are copolymers of (meth) acrylic acid esters and (meth) acrylic monomers having functional groups, or other acrylic resins in addition to the acrylic resins that are the copolymers. For example, an acrylic resin composition obtained by blending, for example, an acrylic resin composed of a single or copolymer of a (meth) acrylic monomer having no functional group, can be used as the resin component of the pressure-sensitive adhesive.

  The crosslinking agent blended in the acrylic pressure-sensitive adhesive can be an isocyanate compound, an epoxy compound, a metal chelate compound, an aziridine compound, or the like. Isocyanate compounds should be used in the form of adducts, dimers, trimers, etc., in which the compounds have at least two isocyanato groups (—NCO) in the molecule, as well as those reacted with polyols. Can do. Specific examples of the crosslinking agent include a trimethylolpropane adduct of hexamethylene diisocyanate and a trimethylolpropane adduct of tolylene diisocyanate as diisocyanate compounds, each used as a solution dissolved in an organic solvent such as ethyl acetate. There are many cases. These crosslinking agents may be used alone or in combination of two or more.

  The weight average molecular weight of the acrylic resin contained in the acrylic pressure-sensitive adhesive is usually about 600,000 to 2,000,000 in terms of standard polystyrene using gel permeation chromatography (GPC), and 800,000 to 1,800,000. Is preferred. If the weight average molecular weight is less than 600,000, the tackiness and durability may be lowered. Moreover, when the weight average molecular weight exceeds 2 million, the pressure-sensitive adhesive layer becomes harder than necessary, and it becomes difficult to peel off after adhesion, or undesired stress birefringence is applied to the protective film or optical compensation film to be bonded. There is a case to give.

  The acrylic resin is dissolved in an organic solvent such as ethyl acetate, and a crosslinking agent is added to obtain an acrylic pressure-sensitive adhesive solution. Further, if necessary, one or more of silane coupling agents, weathering stabilizers, tackifiers, plasticizers, softeners, pigments, and inorganic fillers, and further light diffusing fine particles such as organic beads are included. be able to.

  The acrylic pressure-sensitive adhesive solution thus obtained is usually coated on a release film, heated at 60 to 120 ° C. for about 0.5 to 10 minutes, and the organic solvent is distilled off to form a pressure-sensitive adhesive layer. . Next, after the protective film or optical compensation film is bonded to the pressure-sensitive adhesive layer, it is aged for about 5 to 20 days in an atmosphere of a temperature of 23 ° C. and a humidity of 65%, for example, and the crosslinking agent (C) is sufficiently reacted. Let

  Moreover, after forming an adhesive layer on a peeling film, a peeling film is further bonded and the adhesive layer single sheet which cannot be supported by base materials, such as a protective film, can also be obtained. Also in this case, after the release film is bonded, for example, in an atmosphere of a temperature of 23 ° C. and a humidity of 65%, the film is aged for about 5 to 20 days to sufficiently react the crosslinking agent. In the production of a protective film or an optical compensation film, such a pressure-sensitive adhesive sheet is used by peeling the release film on one side and bonding it to the protective film or the optical compensation film at a necessary time.

  The raw materials for the acrylic pressure-sensitive adhesive as described above can be easily obtained as commercial products, for example, various acrylic monomers (manufactured by Nippon Shokubai Co., Ltd., manufactured by Toagosei Co., Ltd.), polymerization initiator 2 , 2'-azobisisobutyronitrile, etc. (manufactured by Otsuka Kagaku Co., Ltd., Nihon Finechem Co., Ltd.), hexamethylene diisocyanate as a crosslinking agent, and trimethylolpropane adducts thereof, tolylene diisocyanate, and trimethylolpropane thereof Examples thereof include adduct bodies (Mitsui Chemicals Polyurethane Co., Ltd., Sumika Bayer Urethane Co., Ltd.).

  There are also commercially available pressure-sensitive adhesive sheets, such as “non-carrier pressure-sensitive adhesive film / sheet” (manufactured by Lintec Corporation, manufactured by Nitto Denko Corporation).

  The polarizing plate formed as described above, that is, stretched polyethylene terephthalate film / first adhesive layer / polarizing film / second adhesive layer / [protective film or optical compensation film] / adhesive layer / release film A polarizing plate having a layer structure can be peeled from a pressure-sensitive adhesive layer and bonded to a liquid crystal cell to form a liquid crystal panel. This liquid crystal panel can be applied to a liquid crystal display device.

  The polarizing plate of the present invention can be used, for example, as a polarizing plate disposed on the viewing side in a liquid crystal display device. The viewing side refers to the side opposite to the backlight side of the liquid crystal display device based on the liquid crystal cell. The polarizing plate disposed on the back side (backlight side) of the liquid crystal display device may be the polarizing plate of the present invention or a conventionally known polarizing plate.

  The operation mode of the liquid crystal cell to which the polarizing plate is bonded is not particularly limited because it can be adapted by appropriately selecting the optical compensation film bonded to the polarizing plate, but the polarizing plate of the present invention. From the viewpoints of the thin wall, high productivity, etc., which are features of the above, transmissive VA mode or IPS mode liquid crystal cells are preferable, and among them, a relatively large liquid crystal cell for television is more preferable. Moreover, when the anti-glare property is provided to the stretched polyethylene terephthalate film which the polarizing plate of this invention has, it is preferable that the polarizing plate of this invention is used as a polarizing plate by the side of visual recognition.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not prescribed | regulated by these examples. In these examples, “%” and “part” representing the content and the amount used are based on weight unless otherwise specified.

[Production Example 1] Production of polarizing film A polyvinyl alcohol film having an average polymerization degree of about 2,400 and a saponification degree of 99.9 mol% or more and a thickness of 75 µm was immersed in pure water at 30 ° C, and then iodine / potassium iodide. It was immersed at 30 ° C. in an aqueous solution having a weight ratio of / water of 0.02 / 2/100. Then, it was immersed at 56.5 ° C. in an aqueous solution having a potassium iodide / boric acid / water weight ratio of 12/5/100. Subsequently, after washing with pure water at 8 ° C., it was dried at 65 ° C. to obtain a polarizing film in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching was mainly performed in the iodine staining and boric acid treatment steps, and the total stretching ratio was 5.3 times.

[Production Example 2] Production of polyethylene terephthalate film having antiglare layer The following components are dissolved in ethyl acetate at a solid content of 60%, and an ultraviolet curable resin composition showing a refractive index of 1.53 after curing. Prepared.

Pentaerythritol triacrylate 60 parts Polyfunctional urethanized acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate) 40 parts

  Next, with respect to 100 parts of the solid content of the ultraviolet curable resin composition, 2.0 parts of porous silica particles “Silysia” (trade name, manufactured by Fuji Silysia Chemical Co., Ltd.) and a photopolymerization initiator are used. 5 parts of “Lucirin TPO” (manufactured by BASF, chemical name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide) was added to prepare a coating solution.

This coating solution was applied onto a biaxially stretched polyethylene terephthalate film (thickness 38 μm) to form an ultraviolet curable resin composition layer, and dried in a dryer set at 80 ° C. for 3 minutes. The UV curable resin composition layer is irradiated with light from a high-pressure mercury lamp having an intensity of 20 mW / cm ² from the side of the UV curable resin composition layer of the dried film so as to be 300 mJ / cm ^{2 in} terms of the amount of h-line conversion. Was cured to obtain a polyethylene terephthalate film having a haze value of 10%, comprising a laminate of an antiglare layer (cured resin) having irregularities on the surface and a biaxially stretched polyethylene terephthalate film. The haze value was measured using a haze / transmittance meter HM-150 (Murakami Color Research Laboratory Co., Ltd.).

[Production Example 3] Production of active energy ray-curable adhesive composition The following components were mixed to produce liquid adhesive compositions A and B.

(Adhesive composition A)
Bisphenol A type epoxy resin 80 parts Bisphenol F type epoxy resin 20 parts Diphenyl [4- (phenylthio) phenyl] sulfonium hexafluoroantimonate (cationic polymerization initiator) 4.0 parts Benzoin methyl ether (photosensitizer) 1.0 Part

  The epoxy equivalent in the state which mixed the said 2 types of epoxy resin was 186 g / eq, and the total chlorine amount was 1520 ppm. The viscosity of the adhesive composition A measured at 60 rpm with a B-type viscometer at 25 ° C. was 7600 mPa · s. The total chlorine content of the adhesive composition A was measured by a titration method using a silver nitrate solution in accordance with JIS K 7243-3 (ISO 21627-3) (the same applies to the following adhesive compositions).

(Adhesive composition B)
Bisphenol A type epoxy resin 60 parts Bis (3-ethyl-3-oxetanylmethyl) ether 40 parts Diphenyl [4- (phenylthio) phenyl] sulfonium hexafluoroantimonate (cationic polymerization initiator) 4.0 parts Benzoin methyl ether (light Sensitizer) 1.0 part

  The epoxy equivalent of the epoxy resin was 189 g / eq, and the oxetane equivalent of the oxetane compound was 107 g / eq. Moreover, the total chlorine amount of the adhesive composition B was 560 ppm, and the viscosity measured at 60 rpm with a B-type viscometer at 25 ° C. was 670 mPa · s.

[Production Example 4] Production of aqueous adhesive The following components were mixed to produce an aqueous adhesive.

Pure water 100 parts Carboxyl group-modified polyvinyl alcohol [Kuraraypoval KL318 (manufactured by Kuraray Co., Ltd.) 3.0 parts Water-soluble polyamide epoxy resin (aqueous solution with a solid concentration of 30%) [Smiles Resin 650 (sold by Sumika Chemtex Co., Ltd.) )] 1.5 parts

<Example 1>
The biaxially stretched polyethylene terephthalate film (thickness: 43 μm) having the antiglare layer obtained in Production Example 2 is subjected to corona treatment on the bonding surface (surface opposite to the antiglare layer side), and then produced. The adhesive composition A obtained in Example 3 was applied to a thickness of 2 μm by a coating apparatus equipped with a chamber doctor. The aqueous adhesive obtained in Production Example 4 was applied to a saponified triacetyl cellulose film (thickness 80 μm) with a thickness of 2 μm using the same apparatus.

Immediately after applying the adhesive composition to each film, a biaxially stretched polyethylene terephthalate film was applied to one side of the polarizing film obtained in Production Example 1, and a saponified triacetyl cellulose film was applied to the other side. Each was bonded by a bonding roll through the coated surface of the adhesive composition. Then, after irradiating the metal halide lamp from the biaxially stretched polyethylene terephthalate film side so that the integrated light quantity at a wavelength of 320 to 400 nm is 600 mJ / cm ² , a film bonded to a hot air circulation dryer set at 70 ° C. The adhesive on both sides was cured.

  The polarizing plate thus obtained was then wound into a roll by a winding device. The polarizing film, the biaxially stretched polyethylene terephthalate film, and the saponified triacetyl cellulose film had good adhesion, and after the wound polarizing plate was cured for 1 day, Even if it was inserted into the film interface, it could not be peeled off.

<Example 2>
A polarizing plate was obtained in the same manner as in Example 1 except that the adhesive composition B was used instead of the adhesive composition A.

  The adhesion between the polarizing film of this polarizing plate, the biaxially stretched polyethylene terephthalate film and the saponified triacetyl cellulose film was better than that of Example 1, and a sample was immediately taken from the wound polarizing plate, and the cutter Even if a knife was inserted into each film interface, it could not be peeled off.

<Example 3>
The biaxially stretched polyethylene terephthalate film (thickness: 43 μm) having the antiglare layer obtained in Production Example 2 is subjected to corona treatment on the bonding surface (surface opposite to the antiglare layer side), and then produced. The adhesive composition B obtained in Example 3 was applied to a thickness of 2 μm by a coating apparatus equipped with a chamber doctor.

  Moreover, after giving the corona treatment to the bonding surface the triacetylcellulose film (80 micrometers in thickness) which has not performed the saponification process, the adhesive composition B was similarly coated by the thickness of 2 micrometers.

Immediately after coating the adhesive composition on each film, a biaxially stretched polyethylene terephthalate film on one side of the polarizing film obtained in Production Example 1 and a triacetylcellulose film on the other side, respectively. It bonded by the bonding roll through the coating surface of the thing. Thereafter, the metal halide lamp was irradiated from the biaxially stretched polyethylene terephthalate film side so that the integrated light quantity at a wavelength of 320 to 400 nm was 600 mJ / cm ² , thereby curing the adhesive on both sides.

  The polarizing plate thus obtained was then wound into a roll by a winding device. Adhesion between the polarizing film of this polarizing plate, the biaxially stretched polyethylene terephthalate film, and the triacetyl cellulose film that has not been saponified is good, and a sample is immediately taken from the wound polarizing plate and a cutter knife is used. Even if it was inserted into each film interface, it could not be peeled off.

<Comparative Example 1>
The biaxially stretched polyethylene terephthalate film (thickness: 43 μm) having the antiglare layer obtained in Production Example 2 is subjected to corona treatment on the bonding surface (surface opposite to the antiglare layer side), and then produced. The aqueous adhesive obtained in Example 4 was applied to a thickness of 2 μm by a coating apparatus equipped with a chamber doctor.

  Further, a water-based adhesive was applied to the saponified triacetyl cellulose film (thickness: 80 μm) in the same manner as described above.

  Immediately after applying the adhesive to each film, a biaxially stretched polyethylene terephthalate film on one side of the polarizing film obtained in Production Example 1 and a saponified triacetyl cellulose film on the other side, It bonded by the bonding roll through the coating surface of the adhesive agent. Next, the adhesive film was cured by passing the bonded film through a hot-air circulating dryer set to 70 ° C.

  The polarizing plate thus obtained was then wound into a roll by a winding device. Between the polarizing film of this polarizing plate and the biaxially stretched polyethylene terephthalate film, there is no sufficient adhesive force, and after the wound polarizing plate is cured for 1 day, the cutter knife is used with the polarizing film and the biaxially stretched polyethylene terephthalate film. When it was inserted into the interface, it peeled off easily.

<Example 4>
After the biaxially stretched polyethylene terephthalate film (thickness 38 μm) is subjected to corona treatment on the bonding surface, the adhesive composition B obtained in Production Example 3 is thickened by a coating apparatus equipped with a chamber doctor. The coating was applied to a thickness of 2 μm.

  Further, an optical compensation film (thickness 68 μm, in-plane retardation: 63 nm, thickness direction retardation: 225 nm) obtained by stretching a cyclic olefin-based resin film by the above method was prepared, and a corona was applied to the bonding surface. After the treatment, the adhesive composition B was similarly applied to a thickness of 2 μm.

Immediately after the adhesive composition was applied to each film, the biaxially stretched polyethylene terephthalate film on one side of the polarizing film obtained in Production Example 1, the optical compensation film on the other side, and the adhesive composition. It bonded by the bonding roll through the coating surface. Thereafter, the adhesive on both sides was cured by irradiating the high pressure mercury lamp from the optical compensation film side so that the integrated light quantity at a wavelength of 280 to 320 nm was 200 mJ / cm ² .

  The polarizing plate thus obtained was then wound into a roll by a winding device. Adhesion between the polarizing film of this polarizing plate, the biaxially stretched polyethylene terephthalate film, and the optical compensation film is good, and a sample is immediately taken from the wound polarizing plate and peeled off even if a cutter knife is inserted into each film interface. I couldn't make it.

<Reference Example 1>
Similar results can be obtained even when a polarizing plate is produced in the same manner as in Example 1 except that the amount of the epoxy compound in the adhesive composition A is changed as follows.

Bisphenol A type epoxy resin 60 parts Bisphenol F type epoxy resin 40 parts

<Reference Example 2>
The same result is obtained even when a polarizing plate is produced in the same manner as in Examples 2 to 4 except that the oxetane compound of the adhesive composition B is changed to the one shown below.

3-ethyl-3-hydroxymethyloxetane 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane 1,4-bis {[(3-ethyloxetane-3-yl) methoxy] methyl} benzene 3-ethyl- 3- (phenoxymethyl) oxetane 3-ethyl-3- (cyclohexyloxymethyl) oxetane phenol novolac oxetane 1,3-bis [(3-ethyloxetane-3-yl) methoxy] benzene

<Example 5>
The pressure-sensitive adhesive sheet is bonded to the triacetylcellulose film side of the polarizing plate obtained in Example 3 that has not been saponified, and the absorption axis is cut in the long side direction to the screen size of a liquid crystal television described later. A polarizing plate sheet A was obtained. In addition, a pressure-sensitive adhesive sheet is similarly bonded to the optical compensation film side of the polarizing plate obtained in Example 4, and the polarizing plate is cut to the screen size of a liquid crystal television to be described later by aligning the absorption axis in the short side direction. B was obtained.

  The polarizing plate on both sides was peeled off from the liquid crystal panel of a commercially available liquid crystal television equipped with a liquid crystal panel having a vertical alignment mode liquid crystal cell, and the liquid crystal cell was taken out. The polarizing plate sheet A was bonded to the front surface (viewing side) of the liquid crystal cell, and the polarizing plate sheet B was bonded to the back surface (backlight side) through an adhesive sheet to prepare a liquid crystal panel.

  Next, this liquid crystal panel was assembled in a configuration of backlight / light diffusion plate / diffusion sheet / liquid crystal panel to produce a liquid crystal display device. When this liquid crystal display device was operated, defects such as color unevenness were not observed.

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

Claims (6)

A polarizing film comprising a polyvinyl alcohol resin;
A stretched polyethylene terephthalate film laminated on one side of the polarizing film via a first adhesive layer,
Said 1st adhesive bond layer is a polarizing plate which consists of a hardened | cured material layer of a solventless active energy ray-curable composition containing an epoxy compound.   The polarizing plate according to claim 1, wherein the active energy ray-curable composition further contains an oxetane compound.   The protective film or optical compensation film laminated | stacked through the 2nd adhesive bond layer on the surface on the opposite side to the surface where the said extending | stretching polyethylene terephthalate film in the said polarizing film is laminated | stacked is Claim 1 or 2. Polarizing plate.   The polarizing plate according to claim 3, wherein the second adhesive layer is formed of a cured product layer having the same composition as the active energy curable composition.   5. The polarizing plate according to claim 3, further comprising a pressure-sensitive adhesive layer laminated on a surface opposite to the surface on which the polarizing film is laminated in the protective film or the optical compensation film.   A liquid crystal display device comprising a liquid crystal panel, wherein the polarizing plate according to claim 5 is bonded to a liquid crystal cell via the adhesive layer.