TW200842453A - Twisted nematic system liquid crystal display - Google Patents

Abstract

A twisted nematic liquid crystal display in which a view angle can be enlarged using an optical film. The twisted nematic liquid crystal display has such a structure that a liquid crystal cell is held between first and second polarizing plates on the opposite sides from the viewing side, each plate consisting of a polarization film and two sheets of polarizing plate protection film sandwiching the polarization film, wherein the twist angle of liquid crystal in the liquid crystal cell is 115 ± 22 DEG and the Ro and Rt of the polarizing plate protection films on the liquid crystal cell side of the first and second polarizing plates are expressed by the following expressions; 15 ≤ Ro ≤ 70, 70 ≤ Rt ≤ 200, where Ro=(nx-ny)xd, Rt=((nx+ny)/2-nz)xd (In the expressions, nx represents refractive index in the lagging phase axial direction in the plane of the polarizing plate protection film, ny represents refractive index in the direction intersecting the lagging phase axial direction perpendicularly, nz represents refractive index in the thickness direction, and d represents the thickness (nm) of the polarizing plate protection film. Wavelength is 590 nm.)

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical compensation film of a twisted nematic (hereinafter, abbreviated as TN mode) liquid crystal display device, and more particularly to a viewing angle of a TN mode liquid crystal display device. Enlarge the membrane. [Prior Art] Since the TN mode liquid crystal display device has a narrow viewing angle in the structure, an optical compensation film for expanding the viewing angle (hereinafter referred to as a viewing angle expansion film) is generally used. In the viewing angle expansion film system, an optical compensation film obtained by stretching is proposed, but the viewing angle is not enlarged in this method (Non-Patent Document 1). In the TN mode liquid crystal display device, it has been empirically known to adjust the transmission axis of the polarizing plate and the friction axis of the liquid crystal cell for aligning the liquid crystal, in the achievable viewing angle, and There are differences in the ease of adjustment of the viewing angle. The 〇-mode liquid crystal cell used to make the transmission axis of the polarizing plate parallel to the friction axis of the liquid crystal is used as an e-mode liquid crystal cell which is used to make the transmission axis of the polarizing plate perpendicular to the friction axis of the liquid crystal. The degree of the angle of view achieved is slightly worse, but it is generally used from the viewpoint of ease of adjustment. In the market, the liquid crystal unit of the 〇-mode and the disk-shaped liquid crystal coated on the cellulose ester film are widely used (Non-Patent Document 2). This disc-shaped liquid crystal coating type of viewing angle expansion film 'has a faintness of yellow tones from -4-200842453 when viewed in the lateral direction, and thus has been sought to be improved, such as the viewing angle of the disc-shaped liquid crystal coating type described above. In the case where the film is enlarged by the viewing angle at which the optical axis does not exist, the change in the hue during display is increased, and when the viewing angle is viewed from the lateral direction, it is confirmed that the display screen changes to a band (yellow-green spot). Further, the disk-shaped liquid crystal coating type viewing angle expansion film is aligned and fixed by ultraviolet irradiation of the alignment. The hardness of the three positions per molecule is extremely high due to ultraviolet curing, thereby causing heat to the backlight. Waiting for the so-called border spot to become a serious problem. With regard to the problem of yellow coloring, the TN mode has become a problem because the cell gap of the liquid crystal cell is narrowed and the viewing angle in the vertical direction cannot be sufficiently expanded. Therefore, the disk-shaped liquid crystal coating type of the viewing angle enlargement film makes the disk-shaped liquid crystal always have a very high degree of production at a very high degree of arranging. On the market, the use of a disk-shaped liquid crystal and an angular expansion film have been demanded. Non-Patent Document 1: H. Long, Japan Display 92, ρ· Non-Patent Document 2: Fuji Photo Film Research Report, Νο4 6, [Explanation] The problem to be solved by the invention ο Enlarged film, in the display device in white When changing, especially the yellow-green color is used to make the liquid crystal process. However, the above cross-linking has poor durability, and the image display can be gradually reduced in shape at high speed, and it also appears, because it requires technology and is extremely versatile. Field of View 247 (1992) 51 (2001) -5- 200842453 The present invention is directed to a liquid crystal display device which does not have a disk-shaped liquid crystal layer but which is enlarged by a viewing angle expansion film composed only of a stretched film. The viewing angle is versatile. Solution to Problem The above object of the present invention has been achieved by the following constitution. 1 . A twisted nematic liquid crystal display device comprising two polarizing films and a polarizing film protective film sandwiching the film on both sides of the liquid crystal cell, and having the first and second sides from the viewing side A twisted nematic liquid crystal display device having a structure in which a polarizing plate is sandwiched, wherein a twist angle of a liquid crystal in a liquid crystal cell is 1 15 ± 22°, and a polarization of a liquid crystal cell side of the first polarizing plate and the second polarizing plate R 〇 and R t of the sheet protective film are expressed by the following formula. 1 5 ^ Ro ^ 70 70 $ Rt $ 200 夕, F = (nx-ny) χ d

Rt = ((nx + ny)/2-nz)xd (wherein, nx represents the refractive index of the slow axis direction in the plane of the protective film of the polarizing plate, and ny represents the direction perpendicular to the slow axis in the plane) The refractive index, nz represents the refractive index in the thickness direction, and d represents the thickness (nm) of the protective film of the polarizing plate. The wavelength is 590 nm. The magnetic liquid crystal cell according to the above 1, wherein the liquid crystal cell, Department 3 5 0 S AnxdS 5 5 0. Δ η : The birefringence of the liquid crystal in the liquid crystal cell: the liquid crystal cell gap (nm). The twisted nematic liquid crystal display device according to the above 1 or 2, wherein the liquid crystal display device has a first polarizing plate The angle between the transmission axis and the friction axis of the liquid crystal cell substrate on the side close to the first polarizing plate is 3.5 ± 3. The twisted nematic liquid crystal display device according to any one of the above 1 to 3, wherein the liquid crystal display device is normally white. The effect of the invention is according to the present invention, and the stretched film can be used. It is easy to expand the viewing angle of the TN mode liquid crystal display. [Embodiment] The present invention has found that the twist angle of the liquid crystal of the liquid crystal cell in the TN mode is compared with the normal twist angle 90. Slightly moving, not only the 〇-mode, but the e-mode, which is considered to be difficult to enlarge the viewing angle in the TN mode, can expand the viewing angle by using an extended optical compensation film. In the present invention, as in the case of the disk-shaped liquid crystal coating type of the viewing angle expansion film, the film having the optical axis instead of the optical axis does not have a viewing angle expansion film, which suppresses the yellow-green color when the observation direction is changed. The change is made, and the change in the color tone when the direction of observation is changed can be suppressed. 200842453 When the optical axis is present, when the object (layer or film) is observed from the optical axis direction, the phase difference is zero from the observation direction. Therefore, as long as the object is measured by the omnidirectional phase difference, the optical axis can be confirmed in principle, and the optical axis of the present invention is confirmed by using an ellipsometer. Specifically, the in-plane slow phase axis and the phase advance axis are set to ±80 as the tilt axis. The range is measured by phase difference, and it is judged whether or not there is a delay to become the direction of zero. In the present invention, the direction in which the retardation becomes zero in this range is defined as long as it has an optical axis, and if it is not, the optical axis does not exist. Also, the definitions of uniaxial and biaxial are the same as the general definition, and are defined by the number of optical axes. The best mode for carrying out the invention is described in detail below, and the invention is not limited by the scope of the invention. &lt;Liquid Crystal Cell and Twist Angle&gt; The liquid crystal cell of the present invention has two liquid crystal cell substrates, and generally, a glass substrate is used, and a liquid crystal is sandwiched between the unit substrates. In the glass substrate, in order to arrange the liquid crystals in a certain direction, an alignment treatment called rubbing treatment is performed, and the liquid crystal system is correctly aligned along the rubbing direction, that is, the rubbing axis, usually by aligning the two The friction axis of the glass substrate is set to 90. The twist angle is set to 90. . The twist angle of the liquid crystal of the present invention will typically be set at 90. The friction axis of the alignment film on the two glass substrates facing each other is 90. Deliberately moved to 115 ± 22. . In such a way, it is slightly moved, and it becomes a situation in which the expansion of the viewing angle caused by the stretch film of -8-200842453 is caused. Further, in the present invention, the frictional axis of the alignment film near the viewing side is set to 0° as a reference. Further, in general, the transmission axis of the first polarizing plate is at an angle 〇° (in the case of e-mode) or an angle of 90° with respect to the friction axis of the liquid crystal cell substrate on the side close to the first polarizing plate (〇-mode Case), and in the present invention, it is 3.5 ± 3. (in the case of e-mode) or 93.5 ± 3° (in the case of o-mode), especially in the case of 3 · 5 ± 3 ^ (in the case of e - mode). The movement of the torsion angle by 90° and the transmission axis of the polarizing plate and the friction axis are either clockwise or counterclockwise. The important thing is to move in absolute 値. In the liquid crystal display device of the present invention, as in the case of a normal liquid crystal display device, the two polarizing plates are orthogonal polarizers, that is, the transmission axis is 90. The state is opposite. In the rubbing treatment of the present invention, the usual rubbing treatment can be employed as it is. <<Liquid Crystal Cell Gap>> The liquid crystal cell gap in the present invention means the average 値 of the thickness of the liquid crystal layer injected between two glass substrates. The present invention is particularly effective when the gap of the liquid crystal cell is within a certain range, preferably 3 5 0 S Δηχ (1 $ 5 5 0 (nm). 400 S Anxdg 500 (nm) is particularly good. Δη : birefringence of liquid crystal in liquid crystal cell -9- 200842453 d : liquid crystal cell gap (nm) The liquid crystal cell gap is measured using a cell gap measuring device RETS-1 200 (manufactured by Otsuka Electronics Co., Ltd.). Polarizing Plate The polarizing plate of the present invention is formed by sandwiching both surfaces of a polarizing film with a polarizing plate protective film, and can be produced by a general method. Usually, the polarizing plate protective film is alkali saponified and immersed in iodine. The surface of at least one of the polarizing films produced by stretching in the solution is formed by laminating a completely saponified polyvinyl alcohol aqueous solution, and it is preferable to use the method for the polarizing plate of the present invention. The polarizing film of the present invention is not particularly limited in terms of materials, and various materials can be used, and examples thereof include a polyvinyl alcohol film, a partially formaldehydeized polyethylene glycol film, and an ethylene vinyl acetate copolymer partially saponified film. The hydrophilic polymer film 'adsorbs a dichroic substance such as iodine or a dichroic dye as a uniaxially stretched 'polyvinyl alcohol dehydrated material or a polyalkylene oriented film such as a polyvinyl chloride dehydrochlorinated product. Among these, in particular, a polyvinyl alcohol-based film is stretched, and a dichroic material (iodine or dye) is adsorbed and used as an alignment. The thickness of the polarizing film is not particularly limited, but is generally 1 〇 to 8 〇 μηη. A polarizing film which is obtained by iodine dyeing as a uniaxially stretched polyphenylene alcohol film can be exemplified by, for example, immersing polyvinyl alcohol in an aqueous solution of iodine for dyeing, extending to the original length of 3 to 7. It may be prepared by immersing in an aqueous solution such as boric acid or potassium iodide as necessary. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water for washing before dyeing. The polyvinyl alcohol-based film may be washed with water. The dirt or the barrier preventing agent on the surface of the polyvinyl alcohol film is washed, and the polyvinyl alcohol film is swollen to prevent unevenness in staining or the like. The extension system can also be carried out after dyeing with iodine. It may be extended on one side of the dyeing layer, and may be dyed with iodine after stretching. It may also be extended in an aqueous solution of boric acid or iodine: potassium or the like in a water bath. The polarizing film and the polarizing plate are determined by the stretching operation. The transmission axis is the same as the direction of the extension. "Polarizing Plate Protective Film" The polarizing plate protective film on the liquid crystal cell side of the present invention has R 〇 and Rt in the following ranges: 1 5 ^ Ro ^ 70 70 ^ Rt ^ 200夕f, Ro = (nx-ny)xd

Rt = ((nx + ny)/2-nz)xd (wherein nx denotes the direction of the retardation axis in the plane of the protective film of the polarizing plate -11 - 200842453, respectively, and ny denotes the in-plane and retarded axis The refractive index in the vertical direction, nz indicates the refractive index in the thickness direction 'd indicates the thickness (nm) of the protective film of the polarizing plate °)

For the Ro and Rt systems, an automatic complex refractometer KOBRA-21 ADH (manufactured by Oji Scientific Instruments Co., Ltd.) can be used to measure the complex refractive index of the polarizing plate protective film at 5 90 nm in an environment of 23 ° C and 55% RH. Seek. The film thickness of the polarizing plate protective film on the liquid crystal cell side of the present invention is preferably from 1 〇 to 65 μm, and more preferably from 10 to 45 μm. In the case where two polarizing plates of the liquid crystal cell of the present invention are sandwiched, it is preferable that Ro and Rt of the two polarizing plate protective films on the liquid crystal cell side are in contact with the liquid crystal cell in order to satisfy the following relationship. (Δnxd)x〇.35S Total (Ro + Rt)S (Anxd)x〇.85 The following relationship is preferred. In this relationship, the viewing angles of the upper and lower sides can also be fully expanded. (Anxd) x 〇 50S Total (Ro + Rt) $ (Anxd) x 〇. 70 The wavelength dispersion of the polarizing plate protective film of the present invention is preferably in the following relationship. 0.80^ R〇(480)/R〇(630)^ 0.97 0.85^ Rt(480)/Rt(630)^ 0.98 •12- 200842453 In addition, R〇(480) means R〇 measured at a wavelength of 480 nm. , Ro (63 0) indicates R 测定 measured at a wavelength of 63 nm. Same as Rt(480) and Rt(63 0). In the polarizing plate protective film other than the liquid crystal cell side of the present invention, the polarizing plate protective film of the present invention may be used, or other polarizing plate protective film may be used. A commercially available cellulose ester film (for example, KONICA MINOLTA TACK: manufactured by Konica Minolta Optical Co., Ltd., FIHITACK: manufactured by Fujifilm Co., Ltd.) or the like is suitably used. The polarizing plate protective film other than the liquid crystal cell side of the present invention is preferably an optically isotropic polarizer protective film having a Ro of 0 to 20 nm and an Rt of -50 to 50 nm. Further, it is also preferable that the polarizing plate protective film has a hard coat layer or an antiglare layer having a thickness of 8 to 20 μm. [Configuration of Polarizing Plate Protective Film] The polarizing plate protective film of the present invention basically has a polymer film containing an additive such as a plasticizer, an ultraviolet absorber, particles, and a retardation controlling agent. The polarizing plate protective film to which the present invention relates is used as a function of an optical compensation film. In other words, it is preferable that the polarizing plate protective film sandwiching the polarizing film is used as a polarizing plate protective film on the liquid crystal cell side which functions as an optical compensation film. -13- 200842453 [Polymer constituting the protective film of the polarizing plate] The polymer film is not particularly limited as long as it has the above properties, and examples thereof include a cellulose diacetate film, a cellulose triacetate film, and cellulose. a cellulose ester film such as a cellulose acetate butyrate film or a cellulose acetate propionate film, a polyester film, a polycarbonate film, a polyarylate film, a polyfluorene (also containing a polyether fluorene) film, Polyester film such as polyethylene terephthalate or polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film , a syndiotactic polystyrene film, a polycarbonate film, a cycloolefin polymer film (ARTON (manufactured by JSR), ZEONEX, ZEONOR (above, manufactured by ZEON Co., Ltd.), polymethylpentene film, poly An ether ketone film, a polyether ketoximine film, a polyamide film, a fluororesin film, a nylon film, a polymethacrylic film, an acrylic film, or the like. Among them, a cellulose ester film, a cycloolefin polymer film, a polycarbonate film, and a polyfluorene (polyether fluorene) film are preferable, and in the present invention, particularly a cellulose ester film or ring The olefin polymer film is suitably used from the viewpoints of production, cost, transparency, and the like. In particular, it is preferred to use a cellulose ester film from the viewpoint of adhesion. These membranes may be either a membrane produced by melt casting or a membrane produced by solution casting. [Cellulose Ester Film] The cellulose ester suitably used in the present invention is preferably a substituent having the following composition. The substitution degree of the ethyl thiol group is defined as the degree of substitution of the X, propyl fluorenyl group or the butyl fluorenyl group. -14- 200842453 When γ is determined, the mixed fatty acid ester of cellulose having a range of X and Y in the following ranges is used in combination. Formula (I) 2.0 ^ Χ + Υ^ 2.7 Formula (II) 0.10^ 1.2 In addition, 2.4 $ X + YS 2.6, 1·4$ XS 2·3, (total thiol substitution = Χ + Υ) is preferred.

Among them, especially cellulose acetate propionate of 2.4SX + YS2.6, 1.7SXS2.3, 0.1SY ^ 〇 · 9, cellulose acetate butyrate (total thiol substitution = Χ + Υ) is preferred. The portion not substituted by the thiol group usually exists in the form of a hydroxyl group. These cellulose esters can be synthesized by a known method. The cellulose molecule is composed of a plurality of glucose monomers, and has three hydroxyl groups in the glucose monomer. Here, the number of hydroxy groups in which the hydroxy group is induced is referred to as the degree of substitution (% by mole). For example, an ethylene group (actually 2.6 to 3.0) is bonded to all three hydroxyl groups of the cellulose triacetate-based glucose monomer. In the case of the cellulose ester used in the present invention, it is combined with cellulose acetate propionate, cellulose acetate butyrate or ethyl acetate such as cellulose acetate propionate as described above. A mixed fatty acid ester of cellulose of acrylonitrile or butyl sulfonate is particularly suitable for use. Further, in order to adjust to a desired degree of substitution, a cellulose ester having a different degree of substitution may be mixed. In this case, the total substitution degree of -15 to 200842453 may be calculated in accordance with the mixing ratio. The cellulose acetate propionate having a propyl group as a substituent is excellent in anti-H production. It is useful as a film for a liquid crystal image display device. The method for determining the degree of substitution of the thiol group can be determined in accordance with the provisions of ASTM-D817-96. The number average molecular weight of the cellulose ester is 40,000 to 200,000, and the mechanical strength of the &amp; $ type is strong, and it is preferably a moderate coating viscosity in the case of solution casting, and more preferably 500. 0~1 5 0 0 0 0. Further, it is preferable that the weight average molecular weight (Mw) / number average molecular weight (?η) is in the range of 1.4 to 4 · 5. <Method for Producing Cellulose Ester Film> The polarizing plate protective film of the present invention is produced by dissolving a coating material by dissolving an additive such as a cellulose ester and the above-mentioned plasticizer in a solvent, and casting the coating material into a strip shape or The process on the drum-shaped metal support, the process of drying the cast paint as a net, the process of peeling off the metal support, the process of extending the process, the process of further drying, further heat-treating the obtained film, and cooling It is carried out by the usual method of winding the process. Further, a method of dissolving in a solvent and melting by heat may be employed. The polarizing plate protective film of the present invention preferably contains 70 to 95% by mass of the cellulose ester in the solid. A polarizing plate protective film composed of a plurality of layers by a co-casting method can also be suitably used. The polarizing plate protective film may have a layer containing a plasticizer, which may be a core layer, a surface layer, or both, even in the case of a multilayer structure. In particular, the polarizing plate protective film of the present invention has a length of about 100 to 500 m, and is usually provided in the form of a roll. Further, the width of the polarizing plate protective film of the present invention is preferably 1 m or more, more preferably 1.4 m or more, and particularly preferably 1.4 to 4 m. [Cycloolefin polymer film] The polymer forming the polarizing plate protective film of the present invention is preferably a cycloolefin polymer film other than the cellulose ester. Specifically, ZEONEX, ZEONOR, JON, JSR Co., Ltd., and APEL, manufactured by Mitsui Chemicals Co., Ltd., are suitable for use. The molecular weight of the cycloolefin polymer used in the present invention is suitably selected according to the purpose of use, and is determined by gel chromatography of a cyclohexane solution (the toluene solution is not dissolved in the polymer resin). The weight average molecular weight in terms of isoprene or polystyrene is usually from 5,000 to 500,000, preferably from 8,000 to 200,000, preferably from 10,000 to 100,000, and the mechanical strength of the formed body and the formability are highly high. Balance is appropriate. <Method for Producing Cycloolefin Polymer Film> The method for producing the cycloolefin polymer film is not particularly limited, and any of the heat fusion production method and the solution casting method can be used. The heating and melting method can be classified into a compacting method, a press method, a press method, an injection method, a blow molding method, an extension method, etc., and among these methods, In order to obtain an excellent film such as mechanical strength and surface precision, the extrusion production method, the expansion production method, and the blow molding method are preferred, and the extrusion production method is optimal. The cycloolefin polymer film can be obtained by the same method as the cellulose ester film described above, and can be obtained by extending the film in at least a uniaxial direction. Further, the substantial uniaxial stretching may be carried out, for example, after extending in a range in which the alignment of the molecules is not affected, and may be biaxially extended to extend in the direction of the axis of the molecular alignment. It is preferable to use the aforementioned tenter device or the like in terms of extension. [Ultraviolet absorber] The polarizer protective film on the liquid crystal cell side used in the present invention may be an ultraviolet absorber. In this case, the ultraviolet absorber is not particularly limited, and examples thereof include an oxybenzophenone-based compound, a benzotriazole-based compound, a salicylate-based compound, a benzophenone-based compound, and a cyanoacrylate-based compound. A triazine-based compound, a nickel-salted salt-based compound, an inorganic powder or the like. It may also be a polymeric UV absorber. [Particles] Examples of the inorganic compound used in the present invention include cerium oxide, titanium oxide, aluminum oxide, oxidized pin, calcium carbonate, -18-200842453 calcium carbonate, talc, clay, and calcined kaolin. , calcined calcium citrate, hydrated calcium citrate, aluminum citrate, magnesium citrate and calcium phosphate. It is preferable that the particles have a turbidity lower in the case of containing bismuth, and in particular, sulphur dioxide is preferred. The average particle diameter of the primary particles of the particles is preferably 5 to 50 nm, more preferably 7 to 20 nm. These are preferably those having a secondary agglomerate mainly containing a particle diameter of 0.05 to 0·3 μη. The content of the particles in the cellulose ester film is preferably 5 to 1% by mass based on 〇·〇, particularly preferably 0.1 to 0.5% by mass. In the case of a cellulose ester film composed of a plurality of layers produced by a co-casting method, it is preferred that the surface contains such an added amount of particles. The particles of cerium oxide are commercially available, for example, under the trade names of AEROSIL R972, R972V, R974, R812, 200, 200V, 300, R202 &gt; 0X50, ΤΤ600, ΝΑΧ50 (manufactured by Japan AEROSIL Co., Ltd.), and can be used. The zirconia particles are commercially available, for example, under the trade names of AEROSIL R976 and R811 (manufactured by Japan AEROSIL Co., Ltd.), and can be used. Examples of the polymer include a fluorinated resin, a fluororesin, and an acrylic resin. A silicone resin is preferred, especially a mesh structure having a three-dimensional structure. It is commercially available, for example, under the trade names TOSPEARL 1 03, the same 105, the same 108, the same 120, the same 145, the same 3120, and the same 240 (above Toshiba SILICON). Co., Ltd.), and can be used. -19- 200842453 [Oxidation preventive agent, thermal deterioration preventive agent] The oxidation preventive agent and the thermal deterioration preventive agent can be used as generally known. In particular, a lactone-based, sulfur-based, phenol-based, double-bonded, hindered amine-based, or phosphorus-based compound can be suitably used. The lactone-based compound is preferably supplied, for example, by Chiba Specialty Chemicals Co., Ltd., and is commercially available under the trade name of HP_136. The above phenolic compound is preferably a structure having a 2,6-dialkylphenol, for example, from Chiba Special Chemicals Co., Ltd., to ''Irganox 1 076', &quot;Irganox 1 0 1 0&quot The product name of the above-mentioned phosphorus compound is, for example, "Sumilizer GP" supplied by Sumitomo Chemical Co., Ltd., ADK STAB PEP-24G supplied by ADEKA Co., Ltd., ADKSTABPEP - 3 6丨, and "ADK STAB 30 10", "'IRGAFOSP-EPQ" from Chiba Special Chemicals Co., Ltd., and "商品3丫_ P 1 〇1 &quot; The above-mentioned hindered amine-based compound is supplied, for example, by Chiba Special Chemicals Co., Ltd., and is supplied by nTinuvin 144" and "Tinuvin 770," and ADEKA Co., Ltd. as "ADK STAB LA-52". The above-mentioned sulfur-based compound is, for example, Sumitomo Chemical Co., Ltd., and is commercially available under the trade names of 'Sumilizer TPL-R' and 'Sumilizer TP-D1'. The above double bond-binding compound is supplied by Sumitomo Chemical Industries Co., Ltd., and is preferably sold under the trade names of ‘’Sumilizer GM' and 'Sumilizer GS' -20- 200842453. The amount of the oxidation inhibitor or the like which is suitably added is determined, and is generally added in the range of 0.05 to 20% by mass based on the resin of the main raw material of the film. [Plasticizer] In the case where the polarizing plate protective film to be used in the present invention is a cellulose ester film, it is preferable to contain a plasticizer such as the following, from the viewpoints of flexibility, moisture permeability, and dimensional stability. The plasticizer to be used is not particularly limited, and it is preferable to have a functional group which can interact with hydrogen by a cellulose derivative or the like without causing fogging or volatilization or volatilization of the film. As the plasticizer which can be used in the present invention, a phosphate-based plasticizer or a non-phosphate-based plasticizer is suitably used. [Delaying Control Agent] The polarizing plate protective film of the present invention is formed by adding a retardation controlling agent to the film to form an alignment film to form a liquid crystal layer, and to protect the film from the polarizing plate and the liquid crystal layer, in order to improve the crystal quality of the liquid crystal display. The late delay composite can impart optical compensation energy. In order to adjust the compound to be added to the retardation, an aromatic compound having two or more aromatic rings may be used as a retardation controlling agent as described in the European Patent Publication No. 91 1,6 5 6 A2. For example, a rod-like compound can be mentioned. -21 - 200842453 [Bar Compound] The polarizing plate protective film of the present invention is preferably a rod-like compound having a maximum absorption wavelength (λ max) of a UV absorption spectrum of a solution of a short wavelength of 25 nm. In view of the function of the delayed control agent, the rod-like compound is preferably one having at least one aromatic ring, and more preferably having at least two aromatic rings. The rod-like compound is preferably a molecular structure having a straight line. The molecular structure of a straight line means that the molecular structure of the rod-like compound in a thermodynamically most stable structure is a straight line. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation software (for example, WinMOPAC2000, manufactured by Fujitsu Co., Ltd.) is used for molecular orbital calculation, and the molecular structure in which the heat of formation of the compound is minimized can be obtained. The molecular structure is a straight line, which means that the thermodynamically most stable structure obtained by the above calculation means that the molecular structure angle is 140 degrees or more. The rod-like compound is preferably one which exhibits liquid crystallinity. The rod-like compound is preferably one which exhibits liquid crystallinity by heating (having a thermotropic liquid crystal property). The liquid crystal phase is preferably a nematic phase or a smectic phase. Further, it is also possible to use two or more kinds of aromatic compounds. In the aromatic ring of the aromatic compound, an aromatic heterocyclic ring is added in addition to the aromatic hydrocarbon ring. The aromatic heterocyclic ring is particularly preferred, and the aromatic miscellaneous is generally an unsaturated heterocyclic ring. Among them, especially the 1,3,5-three Xiaohuan ring is particularly preferred. -22- 200842453 &lt;Liquid crystal display device&gt; The liquid crystal cell TN mode of the liquid crystal display device of the present invention is formed. The liquid crystal display device of the present invention is not particularly limited except for the liquid polarizing plate of the present invention. Further, the light source is not particularly limited, and for example, from the viewpoint of effective use of light, an embodiment of the present invention is applied to, for example, a plane diaphragm that emits polarized light, and FIG. Fig. 2 1 3 is the first polarizing plate to which the present invention is connected, and 15 is the second polarizing plate to which the present invention is attached. Each of the polarizing plates has a structure in which the polarizing film 2 is sandwiched by two polarizing plate protective films (the polarizing film 2 is sandwiched between the polarizing plate protective film 1 and the second polarizing plate protective film 3 and is sandwiched by 10). The third polarizing plate protective film 9 and the fourth polarizing plate are sandwiched and held. The second polarizing plate protective film 3 and the third polarizing plate protective film S Rt are present in the range of 15 S Ro S 70 and 7 〇 € Rt S 200. 1 4 is a liquid crystal cell gap in which the liquid crystal cell 66 has a liquid crystal cell gap in a space sandwiched by the glass cell substrates 4, 8. The glass unit substrates 4, 8 are provided to apply the liquid crystal layers 5, 7 to the alignment layer for rubbing treatment. In addition, the direction of the rubbing treatment of the twisted pair of the liquid crystal, that is, the angle of the friction axis is the same, the friction axis (determined as the reference 0.) and the friction axis of the alignment film 7, the type, the crystal unit, the light source can also be energized and active. For the best explanation. Ming is connected to the electric film 2,10: by the first, the polarizing film! The film U is &gt; Ro, by two. The angle between the alignment angle of the liquid crystal layer and the alignment film 5 is -23-200842453, 115 士 220 〇 the transmission axis of the first polarizing plate 13 (equal to the transmission axis of the polarizing film 2) and the friction axis of the liquid crystal alignment layer 5 are 3.5±3. The transmission axis of the second polarizing plate 15 (equal to the transmission axis of the polarizing film 10) and the friction axis of the liquid crystal alignment layer 7 are 3.5 ± 3°. Further, the first polarizing plate and the second polarizing plate are disposed so as to be orthogonal polarizers (transmission axes are at an angle of 90° to each other). EXAMPLES Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited thereto. Example 1 &lt;Production of ΤΝ mode liquid crystal cell&gt; The liquid crystal cell was set to have a cell gap (d) of 4·5 μm, and a liquid crystal material having a positive azimuth of a permittivity was dropped and injected between the substrates to be sealed, and the liquid crystal was sealed. The layer Δηχ (1 is set to 45 0 ηπι (Δη is the birefringence of the liquid crystal material). The display area is 10.4. The torsion angle of the liquid crystal cell (the angle between the opposing friction axes) is adjusted as shown in Table 1. &lt;Preparation of cellulose ester film&gt; An optical film composed of a cellulose acetate propionate resin obtained by a solution casting method is produced by the method of the present invention. -24- 200842453 (Modulation of paint) First, the cellulose acetate propionate coating was prepared in the following manner: Cellulose acetate propionate 100 parts by mass (acetonitrile substitution degree 1.95, propylene substitution degree 0.7) Triphenyl phosphate 10 parts by mass 2 parts by mass of phthalic acid monoethylene glycol ester TINUVIN 3 26 (manufactured by Chiba Specialty Chemicals Co., Ltd.) 1 part by mass of AEROSIL 200V (manufactured by AEROSIL Co., Ltd.) 0.1 part by mass of dichloromethane 300 parts by mass of ethanol 40 parts by mass The above materials, in order After the temperature in the vessel was raised from 20 ° C to 80 ° C in a sealed container, the temperature was maintained at 80 ° C for 3 hours, and the cellulose acetate propionate was completely dissolved. Thereafter, The stirring was stopped, and the liquid temperature was lowered to 43 ° C. The coating was filtered using a filter paper (Augmentation filter paper Νο·244, manufactured by Ankye Paper Co., Ltd.) to prepare a coating C1. The FINEMET NF manufactured by Nippon Seisakusho Co., Ltd. The coating liquid was filtered and uniformly cast into a stainless steel belt support at a temperature of 22 ° C and a width of 2 m using a belt casting apparatus. The solvent was evaporated until the residual solvent amount of the stainless steel belt support was 105%, and the peeling tension was 162 N. /m is stripped from the support of the non-mineral steel strip. The web of the stripped cellulose ester is evaporated at 35 ° C to make the slit -25 - 200842453 1.6 m wide, after which the tenter is used It is extended by 1.1 times in the width direction and dried at a drying temperature of 135 ° C. At this time, the amount of residual solvent at the start of stretching by the tenter is 10%. After stretching by a tenter at 130 ° C Relax the width tension and keep the width unwrapped, 1 The drying zone at 20 ° C and 130 ° C was conveyed by a plurality of rolls while drying was completed, and a slit having a slit width of 1.4 m and a width of 10 mm at both ends of the film of 7 μηι was applied, with an initial tension of 220 N/m, and finally Tension 110 N/m was wound around a core of 6 inches in inner diameter to obtain a cellulose ester film sample 1. The elongation ratio in the MD direction calculated from the rotation speed of the stainless steel belt support and the operation speed of the tenter was 1.1 times. The residual solvent amount of the film sample 1 was less than 0.1% each and the film thickness was 40 μm. Ro and Rt are shown in Table 1. In addition, a cellulose ester film sample having other polarizing plate protective films of various R〇 and Rt described in Table 1 was produced by changing and adjusting the production conditions such as the elongation conditions of the cellulose ester film sample 1. (Measurement of R〇 and Rt) The average refractive index of the film was measured using an Abbe refractometer (4T). Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments Co., Ltd.), a film sample was placed in an environment of 23 ° C and 55% RH for 24 hours, and a film having a wavelength of 5 90 nm was used in the same environment. Delayed measurement. The average refractive index described above and the film thickness measured using a commercially available micrometer are input, and the in-plane retardation (Ro) and the delay in the thickness direction -26-200842453 elongation (Rt) are obtained by the following formula.

Ro = (nx-ny)χ d

Rt = ((nx + ny)/2-nz)xd (here, the refractive index of the slow axis direction in the plane of the cellulose ester film is represented by nx, respectively, in the plane perpendicular to the slow axis The refractive index is expressed in ny, the refractive index in the thickness direction of the film is represented by nz, and d is the thickness (nm) of the film. 《) "Preparation of polarizing plate" A long-rolling polyvinyl alcohol film having a thickness of 120 μm is immersed in the mass of iodine-containing 1 100 parts by mass of an aqueous solution containing 4 parts by mass of boric acid, and a polarizing film were produced by extending 5 times in 5 CTC in the transport direction. Next, the cellulose ester film sample 1 subjected to alkali saponification treatment was used as a polarizing plate protective film on one surface of the polarizing film under the following conditions, and a completely saponified polyvinyl alcohol 5% aqueous solution was used as an adhesive for adhesion. On the other surface of the polarizing film, KC4UX manufactured by Konica Minolta Optical Co., Ltd., which was subjected to alkali saponification treatment, was bonded and dried to prepare a polarizing plate 1. (Alkaline saponification) Saponification process 2M-NaOH 5 0 °C 90 sec water washing process water 3 0 ° C 45 sec Neutralization process 10% by mass HC 1 3 0 ° C 45 seconds -27- 200842453 Washing process water 3 0 ° The C 4 5 second saponification treatment, water washing, neutralization, and water washing were carried out in the order of 8 Torr.进行 Dry. (Production of Liquid Crystal Display Device) The polarizing plate 1 and the cellulose ester film sample 1 produced above were bonded to the glass faces on both sides of the liquid crystal cell produced as described above at a predetermined twist angle to prepare a liquid crystal display device. 1 -1. The first polarizing plate and the second polarizing plate are bonded to the liquid crystal cell so as to be a crossed polarizer. In addition, the predetermined torsion angle is adjusted from the viewing side to the clockwise direction. The angle between the transmission axis of the first polarizing plate and the friction axis of the liquid crystal cell substrate on the side close to the first polarizing plate was adjusted to 3.5 °. In addition, the polarizing plate protective film on the liquid crystal cell side of the first polarizing plate and the second polarizing plate in Table 1 is defined as a second polarizing plate protective film and a third polarizing plate protective film. The other liquid crystal display devices 1-2 to 1-26 were also produced in the same manner, and the viewing angles for the right and left up and down were evaluated as follows. (Measurement of the viewing angle) In the viewing angle of the present invention, the viewing angle is measured in eight stages from black display (L1) to white display (L8) using a measuring machine (EZ_c〇'ntrast 160D, manufactured by ELDIM Co., Ltd.) (contrast is 1 〇 above and the black side of the step has no reversal range). -28 - 200842453

Device 2nd polarizing plate protective film 3rd polarizing plate protective film torsional viewing angle (°) Remarks No. Ro (nm) Rt (nm) Ro (nm) Rt (nm) Angle (0) Up, down, left and right 1-1 25 115 25 115 99 42 45 75 The invention 1-2 15 80 15 80 99 40 47 68 The invention 1-3 35 80 35 80 99 39 42 72 The invention 1-4 15 130 15 130 99 35 40 70 The invention 1-5 70 190 70 190 99 43 39 76 The invention 1-6 35 130 35 130 99 37 39 77 The invention 1-7 25 115 25 115 93 38 40 70 The invention 1-8 25 115 25 115 95 39 41 71 The invention 1- 9 25 115 25 115 102 39 40 71 The present invention 1-10 25 115 25 115 105 38 40 70 The present invention 1-11 25 115 25 115 135 36 48 69 The present invention M2 30 125 30 125 110 44 40 76 The present invention M3 30 125 30 125 135 45 38 76 The present invention 1-14 70 150 30 125 110 44 34 78 The present invention 1-15 70 150 30 125 135 44 36 78 The present invention 1-16 25 115 25 115 90 30 32 63 Comparative Example 1 17 25 115 25 115 91 31 32 64 Comparative Example 1-18 25 115 25 115 140 34 28 70 Comparative Example 1-18 10 70 25 115 99 31 48 50 Comparative Example 1-19 25 115 10 70 99 31 39 55 Comparative Example 1-20 15 65 25 115 99 33 40 5 0 Comparative Example 1-21 25 115 15 65 99 32 39 51 Comparative Example 1-22 80 150 25 115 99 30 28 78 Comparative Example 1-23 25 115 80 150 99 30 29 78 Comparative Example 1-24 70 210 25 115 99 31 31 74 Comparative Example 1-25 25 115 70 210 99 32 31 74 Comparison For example, as clearly shown in Table 1, the viewing angle can be easily enlarged in the TN mode liquid crystal display device according to the present invention. -29- 200842453 Embodiment 2 With the configuration of the liquid crystal display device 1 of the first embodiment, the liquid crystal display device 2β1 is produced in the same manner as described in Table 2 except that the unit An xd is adjusted by d. ~2_5, and angle measurement. The liquid crystal is subjected to the field of view [Table 2] Apparatus Δη X d Viewing angle (°) Remarks No. (nm) Up and down left and right 2-1 450 40 43 75 The present invention 2-2 350 45 45 75 The present invention 2-3 550 40 40 71 The present invention 2-4 300 37 37 60 2-5 600 32 40 55 The present invention is as apparent from Table 2, and shows that the viewing angle characteristics are more excellent when Anxci is in the range of 350 to. 5 5 0 (nm) Example 3 The liquid crystal display device 1-1 of the first embodiment was fabricated. The angle between the transmission axis of the polarizing plate and the friction axis of the liquid crystal cell near the first polarizing plate was as shown in Table 3. The varying liquid crystal display device 3 -1 evaluates the viewing angle. And make the first : yuan substrate ~3 - 7, -30- 200842453

Angle of view of the device and the transmission axis (°) Remarks No. (°) Up and down left and right 3-1 0 40 43 75 The present invention 3-2 1 44 48 69 The present invention 3-3 3 44 48 76 The present invention 3-4 6.5 44 49 69 The present invention 3-5 7 48 49 74 The present invention 3-6 90 3 8 38 68 The present invention 3-7 93.5 3 9 39 69 The present invention is as shown in Table 3, showing the transmission of the first polarizing plate When the angle between the axis and the friction axis of the liquid crystal cell substrate on the side close to the first polarizing plate is within the preferable range of the present invention, the viewing angle characteristics are more excellent. [Embodiment 4] The liquid crystal display device 4-1 manufactured by the configuration of the liquid crystal display device 1-1 of the first embodiment, and the third polarizing plate protective film of the first polarizing plate and the third polarizing plate of the second polarizing plate are protected. The film was evaluated using the liquid crystal display device 4-2 of WV FILM SA (manufactured by Fujifilm Co., Ltd.) which does not have a film of an optical axis. The results are shown in Table 4. (Yellow-green spot) Yellow-green spot, the liquid crystal display device produced was displayed in white, and the color tone 60 was measured by the following method. The change is evaluated. Hue 6 0. For the measurement of the change, the Konica Minolta Sensing Unit-31 - 200842453 Co., Ltd. Spectrophotometer CS2000 and the self-made turret are used. For the polarizing plate protective film of the present invention, the polarizing plate is attached to the market. The panel sold is displayed in white, and a 3-color light source (LIGHTVIEWER 7000PRO manufactured by HAKUB A Co., Ltd.) is used for the self-made liquid crystal unit, and the color of the light source is used as a reference to measure the change in hue 60 °. ▲ As the maximum color change, when the absolute 値 of the change amount of the respective coordinate axes of the X - y coordinates is Δ X and Δ y, respectively, the evaluation is based on the following criteria 〇〇· Αχ &lt;0 · 02 and Δ y &lt; 〇. 〇1 △ : 0.02S Δχ&lt;0.2 and satisfy 0S Δυ&lt;〇.2, or 0€ Δχ&lt;0·2 and 0.01^ Δ y&lt;0.2 χ : △ x 2 0.2 or Δ y 2 〇·2 (border Trouble) After each of the created liquid crystal display devices was turned on for 1 000 hours, the presence or absence of light leakage (frame failure) around the black display screen was visually confirmed by %. 〇: The surrounding light leakage is not recognized at all △: The surrounding light leakage is recognized - X: The surrounding light leakage is significant -32· 200842453 [Table 4] Device 2nd polarizing plate protective film 3rd polarizing plate protective film torsion angle optical axis yellow Green border fault preparation No. Ro(nm) Rt(nm) Ro(nm) Rt(nm) (.) Spot 4-1 25 115 25 115 99 The present invention 4-2 20 115 20 115 99 4ffP j\ w Δ Δ The present invention uses one of the liquid crystal display devices 4 to 1 of the present invention having a film of an optical axis, and exhibits excellent characteristics in terms of yellow-green spots and frame failure. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a representative example of an embodiment of the present invention. Fig. 2 is a view showing the relationship between the torsion angle, the friction axis and the transmission axis of the liquid crystal of the polarizing plate of the present invention. [Description of main component symbols] 1 : First polarizing plate protective film 2 : First polarizing film (having a transmission axis of 3.5 ± 3) 3 : Second polarizing plate protective film 4 : Viewing side glass unit substrate 5 : Viewing side liquid crystal alignment Layer (with friction axis reference 0°) 6 : Liquid crystal layer (d : liquid crystal cell gap) 7: Backlight liquid crystal alignment layer (with friction axis 115±221 8 : backlight side glass unit substrate 9 : third polarizer protection) Film 1〇: 2nd polarizing film (having a transmission axis of 93.5±3°) -33- 200842453 1 1 : 4th polarizing plate protective film 1 3 : 1st polarizing plate 14 : TN mode liquid crystal cell 1 5 : 2nd polarizing plate 16: Transmission axis of the first polarizing plate (3.5 ± 3°) 1 7 : Friction axis of the viewing liquid crystal alignment layer (reference 0°) 18: Friction axis of the backlight side liquid crystal alignment layer (11 5 ± 22). 19: Transmission axis of the second polarizer (93.5 x 3°) -34-

Claims (1)

200842453 X. Patent Application No. 1 A twisted nematic liquid crystal display device having two sides of a liquid crystal cell formed by a polarizing film and two polarizing plate protective films sandwiching the film, from the viewing side A twisted nematic liquid crystal display device having a structure in which the first and second polarizing plates are sandwiched, wherein the liquid crystal has a twist angle of 1 15 ± 22 in the liquid crystal cell. And R 〇 and Rt of the polarizing plate protective film on the liquid crystal cell side of the first polarizing plate and the second polarizing plate are expressed by the following formula: 1 5 ^ Ro ^ 70 70 $ Rt $ 200 f, f = (nx -ny) χ d Rt = ((nx + ny)/2-nz) xd where nx represents the refractive index of the retardation axis in the plane of the protective film of the polarizing plate, and ny represents the in-plane and retarded axis The refractive index in the vertical direction, nz represents the refractive index in the thickness direction, and d represents the thickness (nm) of the protective film of the polarizing plate, and the wavelength is 5 90 nm. 2. The twisted nematic liquid crystal display device according to claim 1, wherein the liquid crystal cell satisfies 350$ Δηχ (1$550, Δη: birefringence of liquid crystal in the liquid crystal cell d: liquid crystal cell gap (nm The twisted nematic liquid crystal display device according to the first or second aspect of the invention, wherein the liquid crystal display device has a transmission axis of the first polarizing plate and a liquid crystal cell substrate adjacent to the first polarizing plate side. The twisted nematic liquid crystal display device according to any one of claims 1 to 3, wherein the liquid crystal display device is normally whitened, and the angle of the rubbing shaft is -35-200842453. -36-