TWI377401B - Liquid crystal display device and polarizing plate set useful for the same - Google Patents

Description

1377401 - IX. DESCRIPTION OF THE INVENTION: - Technical Field of the Invention The present invention relates to an In-Plane Switching (IPS), which can be used as a wide viewing angle liquid crystal display device. The invention also relates to a polarizing plate kit for use in the liquid crystal display device. [Prior Art] In recent years, due to the advantages of low power consumption, low voltage operation, light weight, and thin type, liquid crystal display (LCD) is used as a mobile phone, personal digital assistant (pi)^ pers〇nal Digital assistants, personal computers and televisions have seen a rapid increase in the use of information display devices. With the advancement of LCD technology, various different modes of LCD have been proposed to solve the problem of reaction speed and contrast, narrow viewing angle, etc. ★ Moreover, by sandwiching the phase difference plate between the polarizing plate and the glass substrate, the viewing angle can be further improved. In the liquid crystal display device, the liquid crystal display device constituting the IPS mode includes: a liquid crystal cell having a pair of liquid crystals sandwiching the transparent substrate; and a pair of the liquid crystal cells sandwiching the cell a polarizing plate in which the liquid crystal is aligned in the same direction as the substrate surface, and then a parallel toothed comb electrode is disposed on the inside of the substrate (the liquid crystal layer side) of at least one of the pair of transparent substrates, and is applied between the electrodes. The change in voltage causes the direction of the long axis of the liquid crystal to change in a plane parallel to the substrate, and controls the light passing through the front side polarizing plate to perform display. In order to compensate for the birefringence of the liquid crystal display device of the IPS mode and to improve the viewing angle, for example, SID 00 DIGESTp 1〇94_1〇97 (Non-patent Document No. 317754 6 1377401 '1) is known, and the thickness difference plate is effective. . Thickness alignment - One of the manufacturing methods of the phase difference plate is in Japanese Patent Laid-Open No. 7_23〇〇〇7

Japanese Patent Publication No. 1 (Patent Document 1) discloses a method of inducing heat shrinkage in a predetermined form in a heat-resistant resin film formed of uniaxially stretched polycarbonate or the like. Between one of the two polarizing plates disposed in the retardation plate in the thickness direction sandwiching the liquid crystal cell and the liquid crystal cell substrate, the transmission axis of the adjacent polarizing plate is parallel to the slow axis of the phase difference plate The method of configuration is effective in compensating for the birefringence of the liquid crystal cell to expand the viewing angle. In the liquid crystal display device of the (10) mode, the unit cell substrate is arranged to have a negative simple phase difference between the polarizing plates of one of the embodiments. The plate (optical compensation sheet) can improve the viewing angle characteristics. Further, in Japanese Laid-Open Patent Publication No. 2002-258041 (Patent Document 3), it is described that a side of a slow-axis direction is laminated on one side or both sides of a polarizing plate provided with a transparent protective layer on both sides of an absorbing polarizer. 4 Refractive index in the thickness direction... almost equal phase difference plate (optical compensation thin film) ^ In the embodiment of the above Patent Document 3, the biaxial stretching of the polycarbonate having a positive solid solution is obtained, although (1) and (1) A phase difference plate which is almost equal to each other, but which is almost equal to the phase difference plate, is preferably manufactured by uniaxially extending a molecule having a negative intrinsic and refractive index. There have been proposals for materials having a phase difference plate having a negative intrinsic birefringence, for example, in Japanese (4) open 2 (10) 3_m64Q (patent document ^ = = acyclic _ monomer, ring thin smoke monomer It is a phase difference plate with an aromatic vinyl diterpene and a polymer. In addition, it is stipulated in Japanese Patent Laid-Open No. 317754 7 1377401, No. 214325 (Patent Document 5): A ruthenium and a phenyl horse (tetra)imine unit are formed, and a negative (tetra) birefringent copolymer is used as an optical compensation plate or a phase difference plate. Even if the composition described in the above Patent Document 2 or Patent Document 3 is used, it is produced. In the case of the expansion of the angle of view, there is a limit to the increase in the color shift due to the viewpoint, and it is expected to be further improved. The present inventors have proposed the Japanese Patent Laid-Open Publication No. Hei. In Japanese Patent Application No. 2__26444, a phase difference plate having a negative uniaxiality is used in such a manner as to be parallel to the transmission axis of the adjacent polarizing plate and the long axis direction of the liquid crystal molecules adjacent to the unit cell substrate side. Slow configuration of the phase difference plate It is expected that the viewing angle characteristics can be improved. Thus, the phase difference plate having a negative uniaxiality is comparable to the phase difference plate aligned in the thickness direction: it is easy to produce, and the type of the polymer can be selected. Further, in Japanese Patent Application No. 2-12(10) No. 7, it is proposed that the viewing angle characteristics can be further improved by using two phase difference plates having a negative uniaxiality. [Patent Document 1] Japanese Patent Laid-Open No. Hei 7-23_7 (Patent Document No. 1) [Patent Document 2] Japanese Patent Laid-Open No. Hei No. 1Q_54982 (Patent No. 1 and No. 3) [Patent Literature 3] Japanese Patent Special Opening __25 Riding Bulletin (Part 1 of the patent scope) [Patent Document 4] Japanese Patent Laid-Open No. 2〇〇3_2〇764〇 (Application No. 1) 8 317754 8 1377401 • A longitudinal section pattern diagram and (B) are perspective views for explaining the axial relationship. The liquid crystal display device is configured mainly by the liquid crystal cell 50 of the IPS mode. The liquid crystal cell of the IPS mode is also as described above. Is a pair of transparent layers that sandwich one of the liquid crystal layers 53 51, 52' liquid crystal is arranged in parallel with the substrate surface and arranged almost in the same direction. Then, a comb-shaped electrode (not shown) parallel to the inner side (liquid crystal layer side) of at least one of the pair of transparent substrates 51 and 52 is disposed, because The change in the voltage applied between the electrodes causes the direction of the long axis of the liquid crystal to change in the plane parallel to the substrate. The first polarizing plate 1 is disposed on the outer side of one of the substrates 51, and the other polarizing plate 1 is disposed on the other substrate 5 The second polarizing plate 2 is disposed on the outer side. The absorption axis 15 of the first polarizing plate 1 and the absorption axis 25 of the second polarizing plate 20 are normally normal black (normally) in a substantially vertical relationship. Ly black) 'But if the absorption axes of the two are arranged to be substantially parallel, they can also be normal ly white. Further, with respect to the long-axis direction 55 of the liquid crystal molecules in the liquid crystal cell 50 when no voltage is applied, the absorption axis of either of the polarizing plates is substantially perpendicular' and the absorption axis of the other polarizing plate is substantially parallel. In Fig. 1(B), the major axis direction 55 of the liquid crystal molecules is indicated by a blank solid arrow and a blank dotted arrow perpendicular thereto, which means that it is disposed in either direction. In the present invention, the phase difference plate 30 is disposed between the first polarizing plate 1A and the liquid crystal cell 5?. The composite polarizing plate 4 is formed in a state in which the phase difference plate 30 is bonded to the first polarizing plate. In the bonding of the first polarizing plate 1 〇 and the phase difference plate 30, a general adhesive or a pressure-sensitive adhesive (adhesive) can be used. ^ 317754 4 1377401 The first polarizing plate 10 and the second polarizing plate 2 respectively penetrate the linear polarized light vibrating in one direction perpendicular to the plane of the film, and can also absorb the linear polarized light vibrating in the other direction. The first polarizing plate 10 is provided with transparent protective layers 12 and 13 on both sides of the polarizer u. The second polarizing plate 20 is also formed by mounting transparent protective layers 22, 23 on both sides of the polarizer 21. ▲ Specifically, the polarizer 1 can be an iodine-based polarizing film in which a iodine is adsorbed and a polyethylene-based alcohol film, and a dye-based polarizing film in which a dichroic organic dye is adsorbed and aligned in a polyethylene-based alcohol film. The transparent protective layers 12, 13, 22 23 are composed of a general molecular material, for example, triacyl cellulose (tac: tnacetyl celiulose) having a surface treated by saponification (tac) A cellulose-based film such as cellulose (DAc: cellulose) or cellulose propionate. Such a polymer protective film generally has no planar phase difference (nx% ny) and has a thickness, and the refractive index nz of the direction is slightly smaller than the in-plane main refractive index (1) and the negative uniaxial property of the mountain, and the optical axis appears in the approximate method. Line direction. That is, the transparent security: 12, 13, 22, and 23 become the state of the so-called C-board. In the polymer, the thickness direction phase difference Rth of the thin crucible is usually about 1 to 5 〇〇, but in particular, the transparent protective layer 12 on the side where the phase difference plate 30 is disposed = the thickness direction phase difference is set. When the liquid crystal display device of the PS mode is applied in the range of 5 Å to 12 〇 nm, it is extremely advantageous to suppress the color shift due to the viewing angle. The phase difference plate 30 is disposed between the first polarizing plate 10 and the liquid crystal cell 50 so as to exist between the polarizer 11 constituting the first polarizing plate 至 and the phase difference plate 30 317754 14 1377401. The thickness direction phase difference -Rth of the birefringent layer is in the range of -4 〇 nm to +4 〇 nm, and the sum of the plane phase differences is set in the range of 10 至 nm to 20 〇 nm. When the birefringent layer has only the phase difference plate 3G, the unit cell side transparent protective layer 12 of the first polarizing plate 1 is omitted, and the phase difference plate 30 is directly attached to the polarizer u. The difference plate 30 satisfies the above-described phase difference value. However, it is generally advantageous to arrange the cell-side transparent protective layer 12 on the first polarizing plate 10, and therefore, the sum of the phase difference between the phase difference plate 30 and the adjacent transparent protective layer 12 in the thickness direction, and the phase difference of the plane are called. The sum of R and R respectively satisfies the above values. The sum of Rth is preferably in the range of _2 〇 nm to +2 〇 11111, and on the other hand, the sum is preferably set to be 130 nm or more and i80 nm or less. When the sum of Rth • exceeds ± 40 nm, the color shift becomes large due to the viewing angle, and * and, if the sum exceeds the above range, the brightness and the color shift are deteriorated due to the viewing angle, which is less desirable. . The φ structure of the preferred film for the viewing angle compensation of the liquid crystal cell 50 of the IPS mode is such that the cell side transparent protective layer 12 of the first polarizing plate 1 is formed with Rth of approximately 50 to 11 〇 nm. The phase difference plate 30 disposed with the transparent protective layer exhibits a negative uniaxiality and is composed of r. The structure is 13 〇 to 15 〇 nm, and the Nz coefficient is -0.3 to + 〇. 3, the slow axis 35 A of the phase difference plate 3 以 is substantially equal to the absorption axis 15 of the adjacent first polarizing plate 1 〇 It is arranged vertically and is substantially parallel to the long-axis direction 55 of the liquid crystal molecules in the state where no voltage is applied. In the transparent protective layer 22 on the liquid crystal cell side of the second polarizing plate 2, the material is used to form an unaligned film (Rth and tantalum) or a thin layer of the Davis film (Rth = 20 to 40 nm). ) is better. Such a configuration is advantageous in terms of optical characteristics in terms of cost 317754 丄 2)/. The refractive index η of the undoped thin amine on the scallop, and the refractive index η of the η:;7 direction (4) in the plane (4) below 1 ,, W ^ upper benefits such as the thickness direction phase difference to the transparent protection The film system can be produced by using a resin in Example 1. In the case of a cellulose-based film, the thickness difference in the thickness direction can be made small by making the thickness thin. The transparent protective layer of the light plate has a plane phase difference R from the above-described equation (1) due to the phase difference _ ^. It can be in the range of (10) (10) to (4) (10). In particular, it is preferable that it is 120 nm or more and τ is 18 〇ηπ or less. The number of turns represented by the above formula (3) is preferably in the range of from 0.5 to +0.5, and more preferably in the range of from -0.3 to +0.3. The phase difference plate 30 is disposed such that the slow axis 35 is substantially perpendicular to the absorption axis 15 of the polarizing plate 1'. However, it is preferable to use an optical compensation surface of # in the liquid crystal cell of the (10) mode. The first! In Fig. 8 shows an arrangement state in which the absorption axis 15 of the polarizing plate 1 is substantially perpendicular to the slow axis 35 of the phase difference plate 30. Further, the relationship between the phase difference plate 30 and the liquid crystal cell 5 is such that the former slow car is substantially parallel or substantially the long axis direction 55 in a state where no voltage is applied to the liquid crystal molecules on the adjacent transparent substrate surface. The vertical relationship, but preferably the two are generally arranged in parallel. In addition, the term "substantially parallel" or "substantially perpendicular" as used in this specification means that the configuration (parallel or vertical) recorded therein is centered, and the allowable range is ±1〇. about. A preferred embodiment of the phase difference plate 30 is a film having a negative intrinsic birefringence 317754 16 1377401, which is an I-axis extending film, or a compound layer exhibiting a negative uniaxiality and a liquid crystal circle (mdlscotlc). The film. This is a substantially uniaxial phase difference plate. Among them, because of the easy to be good, the polymer with negative birefringence is thinned by a single axis: 2: shows: has a negative uniaxiality, and its optical axis will be in-plane phase difference plate 30 The state indicated by the refractive index expansion. The first system adopts the state of the slow axis 35 in the ellipsoid of the refractive index in the lateral direction, the first axis = Γ = the vertical axis in the plane (fast axis: ization...) adopts the transverse plate property 'the optical axis is in the in-plane direction The phase difference is not shown in Fig. 2. The refractive index structure is in the relationship of the heart, and the ny direction (fast axis direction) in which the refractive index is the smallest is the optical axis. When a polymer having a negative intrinsic birefringence is uniaxially stretched to form a phase difference plate, the polymer to be used may be exemplified by a styrene-based polymer t-dimer or a methyl acrylate-based polymer. , acrylonitrile, methacrylonitrile-based polymer, ethylene-based Cai polymer, ethylene-based biting polymer, vinyl-based salivary polymer, phenyl acrylamide t-polymer, ethylene Biphenyl polymer, ethylene lanthanide polymer, deer, ruthenium polymer, stupid oxy-norbornyl thin polymer, biphenyl carbonyl f-oxygen borneol polymer, naphthyl Rare base polymer, ® weiweisyl norbornene polymer, stupidyloxytetracyclo 4· 〇 · 1 · 1 ]-3-dilute polymer, Phenyl yloxy 1,4-1 ι diene polymer, naphthyl methoxy oxytetralin [4· 4. 0. 1 ·1 ]-3-dodecene polymer, mercaptocarbonyloxy Four 317754 17 1377401 Ring [4. 4· 0·1 . 1 twelve rare polymer, α-ene alkene / n_ stupyl-maleimide-based polymer, etc., but is not limited thereto. Among them, since the tetracyclo[4·4·0·decadiene has the structure of the following formula, it is also called dimethyl octahydronaphthalene. Θ3 Moreover, the above polymer can be mixed with other polymers or made into a copolymer with other monomers, or a high glass transition temperature, can be added to the extent that the negative intrinsic birefringence is not impaired. Or low photoelastic and other functions. The polymer used for the above-mentioned retardation film is preferably a glass transition temperature of 12 m and a copolymer of H, preferably in consideration of the use environment. The glass transition temperature of the copolymer (10) is particularly preferred. Moreover, the photoelastic coefficient of the polymer is preferably 1 〇 X 10 mm kg. Photoelasticity refers to the phenomenon of "birefringence" when an external force is applied to an isotropic substance to cause internal attraction. If the stress acting on the substance is set to σ per unit area and the birefringence is set to Δη, the stress port is proportional to the birefringence T, which can be expressed as Δ n=C σ, which is light Elastic coefficient. Drag + + ^ ^ ^ to set the stress σ acting on the substance on the horizontal axis, and the birefringence Δ η when the stress is set on the vertical axis 'theoretical, both fh become a straight line' and The slope of the line is the photoelastic coefficient. The non-cyclic smog monomer of the fabric compound, and the ring-shaped smog compound 317754 4 1377401 : = smoke monomer And a ternary copolymer of at least one type selected from the group consisting of a bismuth-based fluorene monomer having an aromatic hydrocarbon ring. The following is a description of each monomer component constituting the terpolymer. The non-urban olefin system is selected from the group consisting of ethylene and hydrocarbon compounds. The examples of α-olefin compounds in which qs 0Λ α ^ and 1 〃 and the number of slaves are 3 to 2 可 can be listed as follows: Rare, pentacene, diazo, dioctyl, diterpene, sinene, tetradecene, hexadecene, 1- a linear alpha-olefin having 3 to 20 carbon atoms of octaene or octadecene, or a carbon such as methyl ketone, 3-methyl-p-pentene or 3-methyl-butadiene a branched α-olefin of 4 to 20 or the like. Among them, a propylene or a dibutyl hydride having a carbon number of 2 or a straight chain hydrocarbon having a carbon number of 3 or 4 is used. It is preferable that the obtained copolymer is formed into a film shape, and it is preferable that the ethylene is particularly the same. The above-mentioned ethylene and α-cationic hydrocarbons are used singly or in combination of two or more. A cyclic olefin single system having a polymerizable carbon-carbon double bond in a carbocyclic ring, which is incorporated in the main chain of the copolymer, such as a cyclobutane ring or a ruthenium. a monomer having a pentane ring, a cyclohexane ring, or an alicyclic ring of the two or more bonded rings. Specific examples thereof include, for example, norbornene as in a bicyclic ring [2. 1]hept-2-ene, or 6-alkylbicyclo[2· 2.丨]hept-2-ene, 5,6-dialkylbicyclo[2.2.1]hept-2-ene, 1-alkyl Bicyclo[2. 2.1]hept-2-ene, 7-alkylbicyclo[2·2·1]hept-2-ene introduced into A a norbornene derivative having an alkyl group having 1 to 4 carbon atoms such as an ethyl group or a butyl group, and a tetracyclic ring [4·4·Ο."·5"7, also known as dimethyl octahydronaphthalene. ],, dodecene, and 8-alkylcyclotetracycline 317754 19 1377401 [4·4·0. I2 5. l71°]-3-dodecene, 8,9-dialkyltetracycline [4. 4·0. l2·5. 171°Bu 3~-dodecene dinonyl octahydronaphthalene 8 and/or 9-position dinonyl octahydronaphthalene derivative with a carbon number of 3 or more, especially A derivative of norbornene having one or a plurality of halogens introduced into one molecule, and a derivative of dimethyl human hydrogen naphthalene of four molecules introduced at the 8-position and/or the 9-position. These cyclic olefins may be used singly or in combination of two or more.

♦

Styrene and its derivatives are also included in the aromatic vinyl monomer. The styrene derivative refers to a compound in which stupid ethylene is bonded to other groups, and examples thereof include, for example, o-nonyl stupid ethylene, m-decyl styrene, p-nonyl stupid ethylene, 2,4-methyl styrene, ortho Ethyl styrene, alkylstyrene of p-ethylstyrene; or such as hydroxystyrene, tert-butoxystyrene, ethylene benzoic acid, 2 dilute benzyl acetate, o-chlorostyrene, A hydroxy group, alkoxy group, a carboxyl group, a decyloxy group, a dentate or the like introduced into a benzene nucleus of a styrene of a styrene, such as a substituted stupid ethylene or a vinyl biphenyl, a 4-hydroxy-4, _vinyl biphenyl The vinylbiphenyl compound 'especially' is, for example, a B-baked naphthalene or a 2-naphthyl naphthalene naphthalene compound. As described in the content of these monomers, when the aromatic vinyl monomer is very: >, the Japanese Guard, it is less desirable because it has a positive intrinsic birefringence, and conversely, when the amount is large, The photoelastic coefficient becomes larger and less desirable. Further, when the amount of the cyclic olefin monomer is small, the glass transition temperature becomes low and is less desirable, and conversely, when the amount is too large, the copolymer becomes weak and is still unsatisfactory. Wherein, the aromatic vinyl monomer is agglomerated at a ratio of about 5 to 50 mol% of the acyclic thinner monomer and the cyclic olefin monomer at a ratio of about 5 to 95 m 2 20 317754 1377401 appropriate. The ternary copolymer having such a copolymerization ratio is particularly advantageous in terms of heat resistance of the phase difference plate. More specifically, for example, a non-cyclic olefin monomer is formed of ethylene, an aromatic vinyl monomer is made of stupid ethylene, and a tetracyclic ring [4 . 4 . 〇 . 1 2. 5. 1 7, 1 is used. _ 3-Dodecene constitutes a terpolymer of a cyclic olefin monomer by setting styrene to 15 to 25 mol%, tetracyclo[4.4.0.125.17, hydrazine. The -3-dodecene is preferably 25 to 35 mol%, and is preferably a resin having a negative birefringence and a glass transition temperature which is relatively low in photoelasticity. Other preferred polymers which have a negative intrinsic birefringence, such as a glass transition temperature and a low photoelasticity, include: an α-olefin unit and an N-phenyl maleimide unit. Copolymer. The copolymer is specifically a unit having the following formulas (I) and (II).

The alkyl group of the formula (I) to 6; the hydrogen atom in the formula (11), and the R2 and R3 groups are each independently, and represent hydrogen or carbon number, Rs, Re, Rt, Re, 'K4, R5, R6, R7. , R8, R9 and each are independently, 4 atomic atoms, several groups or a carbon number of 1 to 8. 317754 21 1377401 Winter formula (1) represents a unit of an α-olefin in which R1, R2 and r3 are each independently represented as a hydrogen atom or a carbon number! To 6 alkyl groups. When it is silk, the base may be linear; if it is 3 or more, it may be isopropyl, isobutyl, t-butyl or tert-butyl. Among the α-olefins which can impart a branch to the unit of the formula (I), it is preferred to use a carbon number of 4 or more, ruthenium and R3 as a base. Formula (II) represents a fluorenyl-phenylmaleimide unit in which R4, Rs, Re, and Rg are independently represented by each other, and represent a hydrogen halogen, a carboxyl group C00H, or a carbon number! To 8 base. When any of these is dentin, examples of the halogen include fluorine, gas, bromine, iodine and the like. When any of 匕 to 匕 is an alkyl group, the carbon number is 丨 to 8, which may be linear; carbon number, 3 or more oxime, may be isopropyl, isobutyl second butyl, third Butyl * and other knife-shaped. In the case of the group 1, the &, Re, and the aspect on the benzene ring, at least one of them is preferably a group other than a hydrogen atom, in particular, an alkyl group at the R4 of the 2_ position, ie, or at the 6-position. It is better. In the formula (II), Re which is present on the carbon atom of the maleimide and each independently may be hydrogen, a halogen, a carboxyl group (-(3)(10)) or an alkyl group having a carbon number of from 8 to 8. For the dentate and the alkyl group at this time, the same description as above is also given. It is preferred that the Rg and L which are present on the carbon atom of the maleimide are usually hydrogen. Further, it is also effective as a halogen or a carboxyl group of a polar group. Examples of the compound which imparts the α-olefin unit of the formula (I) include isobutylene, 2-methyl-1-butene, 2-methyl-1-pentene, 2-mercapto-fluorene-hexene, 2-mercapto-1-heptene, 2~methyl-1-octene, 2-ethyl-1-pentene, 2-mercapto 22 317754 \§) 1377401 '-2-butene, 2-曱Alkyl-2-pentene, 2-mercapto-2-hexene, ethylene, propylene, 1-butene, 2-butene, p-hexene, and the like. These may be used alone or in combination of two or more kinds in the polymerization. Examples of the compound which imparts the N-maleimine unit of the formula (II) include, for example, N-phenylmaleimide, N-(2-mercaptophenyl)maleimide, N- (2~ethylphenyl)maleimide, n-(2-isopropylphenyl)maleimide, N-(3-methylphenyl)maleimide, N-( 3-ethylphenyl)maleimide, N-(4-mercaptophenyl)maleimide, N-(4-ethylphenyl)maleimide, N-(2 , 6-dimethylphenyl)maleimide, N-(2,6-diethylphenyl)maleimide, N-(2,6-diisopropylphenyl)male Yttrium, N-(2'4,6-tridecylphenyl)maleimide, n-(2-, 3- or 4-carboxyphenyl)-maleimide, N-( 2, 4-Dimethyl stupyl) maleic imine and the like. These may be used alone or in combination of two or more kinds in the polymerization. As described above, a compound which imparts an α-hydrocarbon unit of the formula (I) and a compound of a maleimide unit which imparts a formula (I) can be produced by a conventional method to produce a negative The α-olefin/Ν_phenylmaleimide copolymer used for the uniaxial optical axis in the in-plane direction. At this time, it is also possible to copolymerize with other small amounts of ethylene monomer as long as it does not impair negative uniaxiality, heat resistance and photoelasticity. Other vinyl monomers include, for example, styrene, α-mercaptostyrene, and vinyl benzene. ^ As described in the respective alpha olefin/Ν-phenyl maleimide copolymers, when the amount of phenyl maleimide is too small, it will show positive Refraction, because the glass transition temperature is also lowered, it is not good, 23 317754 8 1377401 • Conversely, if the amount of N-phenyl maleimide is too large, the photoelastic coefficient will become large and the copolymer will become weak, so it remains not ideal. Therefore, the copolymerization is preferably carried out at a ratio of about 5 to 95% of the Liaoyihe unit and about 5 to 10% of the unit. Further, in order to prevent a decrease in the glass transition temperature, an alkylmaleimide may be used as a monomer insofar as it does not interfere with the optical properties of the polymer. The polymer as described above is thinned, and the phase difference plate can be obtained by stretching in an appropriate manner. In order to obtain a phase difference with a small difference in phase difference, it is extremely important to impart an optical (4) film extension. Although the thin film is different? The method of knowing 'for example: smelting and extruding method, solvent washing tungsten method, expansion method, etc., but as long as the thickness of the thin crucible is small, the phase difference is:: optically isotropic film, then - The method can be applied. In the film thus obtained, a uniform phase difference can be imparted by conventional means. Extension method Biaxial thermal extension method. The uniaxiality of the optical becomes important !# !: The early axis > method can be cited as the free end longitudinal uniaxial extension. & extension The use of the poor plate system to show negative uniaxiality, can be applied to pay. In the in-plane direction, the viewing angle characteristic of the liquid crystal display device of the 彳 mode is in the in-plane direction and the phase of the negative uniaxial phase is extended. Two directions = extension::: extension of the extended film (phase difference plate) 'polarized plate The direction of extension becomes the absorption axis, and the straight direction of the 24 317754 (§) 1377401 becomes the transmission axis. Therefore, when the phase difference plate and the polarizing plate thus obtained are attached to the wheel to the wheel, a composite polarizing plate in which the slow axis of the phase difference plate is perpendicular to the absorption axis of the polarizing plate can be obtained. Thus, the number of manufacturing steps is reduced, and the target composite polarizer can be efficiently manufactured. Next, a description will be given of a phase difference plate in which a layer which exhibits a negative uniaxial liquid crystalline discotic liquid crystal compound has a negative uniaxial property and whose optical axis is in the plane. The liquid crystalline discotic liquid crystal compound refers to a compound which exhibits liquid crystal properties and exhibits a disk shape in a molecular form, and is coated on a transparent plastic film in a molten state or in a solution dissolved in a suitable solvent. In a predetermined direction in which the disk surface and the film surface are parallel, the disk is erected on the film surface so that the disk is aligned in a predetermined direction, and the solvent is directly solidified or the solvent is removed while maintaining the alignment. The layer of the liquid crystal discotic liquid crystal compound obtained by this method exhibits a negative uniaxiality and becomes an in-plane state of the optical axis (fast axis). By this method, a phase difference plate having a refractive index ellipsoidal structure as shown in Fig. 2 can also be produced. In the case of aligning the liquid Ba-shaped discotic liquid crystal compound, a general method such as use of an alignment film, friction, addition of an optically active dopant (chiral d〇pant), or irradiation of light can be employed. Further, the liquid crystalline compound can be cured by aligning the liquid crystalline discotic liquid crystal compound to "fixed alignment". As described above, since the disk exhibiting the uniaxial stretching of the polymer having a negative intrinsic birefringence and the negative uniaxial liquid crystalline discotic liquid crystal compound are aligned so as to stand upright on the substrate film, Although it is possible to produce a phase difference plate having a Nz coefficient of about 〇 as shown in the previous formula (3), when extending, for example: using a fixed end longitudinal uniaxial extension or a transverse uniaxial extension of the tenter to hold 317754 (§ 1377401 is also axial, thereby forming nz >nx>ny' at this time to obtain a phase difference plate (Nz=-G.UG) having a negative Nz coefficient. That is, the Nz coefficient is at _〇5

The uniaxial phase difference plate which is negative to the circumference of 〇 can be produced, for example, by uniaxially stretching a polymer having a negative birefringence. A polymer having a negative intrinsic=refracting property: a non-cyclic olefin monomer selected from the group consisting of a woman and a carbon number 3 to (10), and a cyclic hydrocarbon compound selected from the group consisting of a cyclic chiral compound... The aromatic private monomer series selected from the vinyl compound having an aromatic hydrocarbon ring is 5 to 10% by mole of the aromatic vinyl monomer, and the sum of the non-cyclic olefin monomer and the cyclic olefin monomer. The copolymer which is polymerized at a ratio of from 5 Å to π mol % is preferable in terms of heat resistance of the phase difference plate. On the other hand, by the method described in the above Patent Document 1, • A polymer having positive intrinsic birefringence is processed to form nx > n2 > ny, in which case a thickness-aligned phase difference plate having a Νζ coefficient of 〇 to +〇9 can be obtained. The phase difference plate used in the method is such that the Νζ coefficient becomes 〇 to +0·5. That is, the thickness difference plate whose Νζ coefficient is 〇 to +0. 5 is oriented according to the above-mentioned patent document 1 The method described is to uniaxially polymer a polymer having positive intrinsic birefringence After being extended, it can be made by shrinking in a predetermined pattern. The polarizing plate set according to the present invention is combined with the first polarizing plate 10 and the phase difference plate disposed on one side thereof as shown in the figure. The polarizing plate 40 and the second polarizing plate 2'' are formed in a state of being bonded to the front and back surfaces of the liquid crystal cell. The respective optical characteristics are in accordance with the above description. In the IPS mode liquid crystal cell The composite polarizing plate 4 is disposed on one side, so that the side of the phase 317754 26 1377401 difference plate 30 faces the liquid crystal cell, and the second polarizing plate 20 is disposed on the other side of the liquid crystal cell, so that the thickness direction phase difference Rth When the transparent protective layer 22 in the range of _1〇ηιη to +4〇11〇] faces the liquid crystal cell, an IPS mode liquid crystal display device having improved viewing angle characteristics can be obtained. [Embodiment] The following display embodiment is more The present invention is specifically described, but the scope of the present invention is not limited to the examples. Lu Comparative Example 1: Prepared in the iodine adsorption alignment on the double-sided side of the polyvinyl alcohol polarizer with triethylenesulfonate Linear polarizing plate made of transparent protective film "SRW842A" [manufactured by Sumitomo Chemical Co., Ltd.] In the linear polarizing plate, the Rth of the transparent layer is 55 nm, the R 〇 is 1 nm, and the slow protective layer is slow and the shaft is separated from the polyvinyl alcohol. - The absorption axis of the iodine-based polarizer is arranged in parallel. The liquid crystal cell in the lps mode [the "linear layer cell" manufactured by Hitachi, Ltd." is disposed only on the both sides of the "linear layer polarizer" SRW842A, a liquid crystal display device having a configuration in which a phase difference plate is not disposed. In this case, in the front side (viewing side), it is perpendicular to the long axis direction (orthogonal direction) of the liquid crystal molecules when no voltage is applied. The absorption axis of the linear polarizing plate is disposed, and the front side linear polarizing plate and the back side linear polarizing plate are disposed so as to be perpendicular to the absorption axis, respectively. Here, the layer constitution of the liquid crystal display device and the relationship of the axes are as shown in Fig. 3. The symbol meaning of the elements in Fig. 3 is the same as that of Fig. j. Fig. 3 is only the point where the phase difference plate 30 is not disposed, and the long axis direction 55 of the liquid crystal molecules is fixed at the direction of the blank solid arrow direction and the first! The picture is different. The backlight is turned on by the back surface of the liquid crystal display device, and when the color shift and brightness of the 317754 27 1377401 are visually observed by the naked eye, the luminance changes due to the viewing angle are large, and the viewing angle dependence is high. Example 1 (a) Preparation of composite polarizing plate A transparent protective film made of diethyl fluorinated cellulose was attached to both sides of a polarizer of polyvinyl alcohol in an iodine adsorption alignment (the Rth of one piece was 65 nm). , RQ is inm) linear polarizer. On the other side of the protective film, a free-length longitudinal uniaxially stretched film of polystyrene having a negative intrinsic birefringence is used. With a polyvinyl alcohol-based adhesive, the enthalpy is 14 〇 nm and the Nz coefficient is 0.0. The phase difference plate is attached, and the absorption axis of the linear polarizing plate is perpendicular to the slow axis of the phase difference plate to form a composite polarizing plate. • (b) Production and evaluation of the liquid crystal display device • The ft is the same as the IPS mode liquid crystal cell “w_3000” in front of the first example (the viewing side), and the above (4) is made by the acrylic pressure-sensitive adhesive. The composite polarizing plate is laminated in the order of the cell substrate side, the phase difference plate, and the linearly polarized light plate. On the back surface (backlight side), only the moth-based linear polarizing plate is used by the acrylic acid-sensitive crimping agent. Laminated. The linear polarizing plate used on the back side is a single-sided paste of a polarizer that is adsorbed to a polyethylene glycol, and has a protective film formed of a norbornene-based resin. [optes] 〇n〇r,,, as 4nm], on the other side, a protective film made of triethyl fluorenyl cellulose is bonded to the protective film side made of the norbornene-based resin. It is bonded to the unit cell substrate by an acrylic-based pressure-sensitive adhesive. At this time, the slow axis of the phase difference plate is parallel to the long-axis direction (alignment direction) of the liquid crystal molecules when no electric dust is applied. The 317754 28 1377401 is arranged in a manner. Further, the front side linear polarizing plate and the back side linear polarizing plate are disposed perpendicularly to the absorption axis. The layer structure and the axis relationship of the liquid crystal display device produced here are as follows. 4 is the same as Fig. 1 in Fig. 4, and Fig. 4 is different from the jth diagram only in the point where the long axis direction 55 of the liquid crystal molecules is fixed in the direction of the blank solid arrow. The back of the display device lights up the backlight to the naked eye When the color shift and the shell degree of the viewing angle were changed, it was confirmed that the color shift and the luminance change were small as compared with Comparative Example 1. • Example 2 except that the phase difference plate was changed to R, which was 13 〇 nm, and the Nz coefficient was The evaluation was carried out in the same manner as in Example 1 except that the longitudinally uniaxially extending polystyrene film was used, and as a result, it was confirmed that the color shift and the brightness change due to the viewing angle were small. The polarizing plate on the back side was changed to Sumitomo Chemical Co., Ltd., SRW042A" (34 nm on one side of the transparent protective layer), and was evaluated in the same manner as in Example 1. As a result, it was confirmed that the color shift and the degree of change due to the angle of view were small. Example 4 Sumitomo Chemical Co., Ltd. was coated with a transparent protective film made of triethyl cellulose on the double side of a polarizer of polyvinyl alcohol (one piece of Rth was ll 〇 nm, h was 7 nm). A linear polarizing plate "SR2〇42A, one side of the protective film side" is a free-end longitudinal uniaxially stretched film of polystyrene having a negative intrinsic birefringence by a polyvinyl alcohol-based adhesive. R (j is a phase difference plate of 29 317754 1377401 16 〇 nm, which fits the '', and the absorption axis of the linear polarizing plate is perpendicular to the k-axis of the phase difference plate to form a composite polarizing plate. In addition to being disposed in front of the liquid crystal cell The composite polarizing plate on the side was changed to the same as that of the manufacturer, and evaluated in the same manner as in Example 1. As a result, it was confirmed that the color shift and the change in luminance due to the viewing angle were small.

The molar ratio of ethylene to stupid ethylene to tetracyclo [4.4.0. I2 5. Γ'ι °]-3-dodecene is 5 〇: 2〇: 3〇 copolymer (by pressure molding) Referred to as ESD), it is a film having a thickness of i00//m. The film was uniaxially stretched in an automatic curve to exhibit a negative birefringence to form a phase difference plate having a plane phase difference of 140 nm and an Nz coefficient of 〇.〇. A composite polarizing plate was produced in the same manner as in Example 除了 except that the uniaxially stretched polystyrene film was replaced by the retardation film, and a liquid crystal display device was produced. With respect to the liquid crystal display device, when evaluated in the same manner as in Example 1, the same results as in Example 1 were obtained, and it was confirmed that the positive and oblique luminance changes and the color shift were small. Comparative Example 2 The phase difference plate "SEZ270135" manufactured by Sumitomo Chemical Co., Ltd. was made of polycarbene and had a thickness of 135 nm, an Rth of -41 nm, and an Nz coefficient of 0.2. In the same manner as in the linear polarizing plate SRW842A (the Rth of one surface of the transparent protective layer is 55 nm, which is 1 nm), the phase difference of the above-mentioned thickness is adjusted by an acrylic pressure-sensitive adhesive. The plate "SEZ2701 35" is attached to the 'axis so that the absorption axis of the linear polarizing plate is perpendicular to the slow axis of the phase difference plate to form a composite polarizing plate. The 30 317 754 1377401 composite polarizing plate was placed on the front surface of the liquid crystal cell (viewing side). 'On the liquid crystal cell, the same linear polarizing plate "SRW842A" as that used in Comparative Example 1 was disposed (the transparent protective layer was single-sided). A liquid crystal display device was produced in the same manner as in Example 1 except that Rth was 55 nm. When the liquid crystal display device was evaluated in the same manner as in Example 1, the change in luminance due to the viewing angle was small, but the color shift was extremely remarkable as compared with Comparative Example 1. In the above Comparative Example 1, Examples 1 to 5, and Comparative Example 2

The results obtained under the conditions are summarized in Table 1. [Table 1 ]

Comparative Example Comparative Example 1 1 2 3 4 5 2 Front side polarizing plate cell side protective layer Rth 55 nm 65 nm 65 nm 65 nm 1 l Onm 65 nm 55 nm Cell side protective layer R 〇 lnm lnm lnm lnm 7 nm lnm lnm phase difference plate Material Μ No PS PS PS ESD PC Rth — -70nm -65nm -70nm -80nm -70nm -41nm R〇 - 140nm 130nm 140nm 160nm 140nm 135nm Nz coefficient - 0. 0 0. 0 0.0 0.0 0.0 0. 2 Cell side The sum of the protective layer and the phase difference plate Rth 55 nm - 5 nm Onm - 5 nm 30 nm - 5 nm 14 nm R 〇 l 141 nm 131 nm 141 nm 167 nm 141 nm 136 nm Back side polarizing plate cell side protective layer Rth 55 nm 4 nm 4 nm 34 nm 4 nm 4 nm 55 nm Light leakage * 2 X ◎ ◎ 〇〇 ◎ Δ color shift *3 Δ ◎ ◎ ◎ ◎ ◎ X 31 317754 (3⁄4 1377401 material PS: ESD: polystyrene ethylene and styrene and diene molar ratio four rings [4. 4. 0. I2'5. Γ〗 °]-3-10: 20: 30 terpolymer PC · Polycarbonate * 2 light leakage ◎: good. 〇·· Although the oblique direction is slightly leaky, it is generally good. ^ : There is light leakage in the oblique direction. X : There is a large light leakage in the oblique direction. * 3 Polarized light ◎: Good △, oblique color shifting. X · Oblique color is too large. • Comparative Example 3 (a) Preparation of composite polarizing plate: Preparation for iodine adsorption alignment on the double-sided bonding of polyvinyl alcohol polarizer a transparent protective film made of acetyl cellulose (one piece of Rth is 52 nm, R is inm), and on the other side of the protective film, a thickness-aligned phase difference plate made of polycarbonate. By using an acrylic pressure-sensitive adhesive, R is 135 nm, Rth is -27 nm, and the Nz coefficient is 〇. 35, which is laminated, 'the absorption axis of the linear polarizing plate is perpendicular to the slow axis of the phase difference plate' to form a composite. (b) Production and evaluation of liquid crystal display device IPS mode liquid crystal cell ["w〇〇〇5000" manufactured by Hitachi, Ltd.) [front side (visual side), with acrylic pressure-sensitive adhesive The above-mentioned 317754 8 1377401 • (a) The composite polarizing plate produced is laminated in the order of the cell substrate side, the phase difference plate, and the linear deflecting plate, and the acrylic back pressure resisting agent is still only used on the back surface (back side) a straight line before the phase difference plate is attached in the above (a) Polarizing plate (Rth is 52 nm, R. For the inm2 transparent protective film attached to the double-sided) :: layer. On the front side, the slow axis of the phase difference plate is arranged in parallel with the long axis direction (orthogonal direction) when no liquid is applied to the liquid crystal unit cell, and the front side is disposed so as to be perpendicular to the absorption axis. Straight line polarized plate and moon side linear polarizer. The layer 1 and the axial relationship of the liquid crystal display device produced here are as shown in Fig. 4. The backlight of the liquid crystal display device was turned on, and the contrast change and the color shift produced by the viewing angle were measured by the liquid crystal viewing angle/chromaticity specific measuring device "EZ Contrast" manufactured by ELDIM.

Figure 5 shows the comparison curve at this time. In the comparison curve, let 'the right is ^. , the direction of the positive half of the table is changed to half (the table is not "by 0 1315 ° every 45."), and the "20", 70 on the horizontal axis means the azimuth from the normal Tilt angle (elevation angle). For example, the right end of the circle means the azimuth is 〇. (The right side of the figure) The 0 angle is the contrast of the direction of 80. In the comparison of the curve of 2〇〇, CR 200′′, as it goes to the inside, the comparisons become the contrast curves of _, 刚, _, etc., respectively. The graphs showing the comparison curves shown below are also of the same meaning, and the detailed description is omitted when the graph of the equal contrast curve appears. Shi Jin. The contrast of the month shows white (applied voltage to the liquid crystal cell). 1. The ratio of light 317754 (§) 1377401 degrees when it is not black (no voltage applied to the liquid crystal cell). - Figure 6 is a plot of X, y chromaticity from the measured viewing angle in this example. The closed curve on the outer side represents the monochromatic light trajectory of the stimulus value of the monochromatic light. The maximum point of the X in the right end is 78 〇 nm, and the maximum point of the upper y is about 52 〇 nm, and then in the lower left y The minimum point is the wavelength equivalent to 38〇1^. • In the vicinity of (x=0·33, y=〇.33), it corresponds to white, and the outer right side of the closed curve is equivalent to red, the upper side is green, and the lower left side is blue. The closed curve on the inner side is the actual measurement data, and the elevation angle U疋 is at 60, and the black color (no voltage applied to the liquid crystal cell) is used to make the azimuth angle sequentially zero. To 360. The chromaticity of the rotation indicates that the smaller the area of the closed curve, the smaller the color shift due to the angle of view. The X and y chromaticity diagrams appearing below have the same meaning. Therefore, if x, y chromaticity diagrams appear below, detailed descriptions are omitted. From the fifth and sixth figures, the liquid crystal display device of Comparative Example 3 is particularly large in color shift due to the viewing angle. _Example 6 (a) Preparation of composite polarizing plate A transparent protective film made of triethylenesulfonyl cellulose was attached to both sides of a polarizer of polyvinyl alcohol adsorption iodine (1 piece of Rth was 65) A linear polarizer that catches and smashes into lnro. On the other side of the protective film side, a free-end longitudinal uniaxially stretched film of polystyrene having a negative intrinsic birefringence is used, and a polyvinyl alcohol-based adhesive is used to provide a phase difference plate having a crucible of 14 〇 nm and an Nz coefficient of The composite polarizing plate is formed by laminating the absorption axis of the linear polarizing plate perpendicular to the slow axis of the phase difference plate. 317754 34 1377401 (b) Production and evaluation of liquid crystal display device The above-mentioned (a) was used by an acrylic pressure-sensitive adhesive before using the same I ps mode liquid crystal cell 5000" as in Comparative Example 3 (viewing side) The composite polarizing plate of the clothing layer is laminated in the order of the unit cell substrate side, the phase difference plate, and the linear polarizing plate, and only the iodine-based linear polarizing plate is laminated on the back surface (backlight side) by an acrylic pressure-sensitive adhesive. The linear polarizing plate used on the back side is a non-aligned protective film made of norbornene-based resin on the single side of the iodine-adsorbing polarizer that is oriented to polyvinyl alcohol. [The zeonor manufactured by Optes. ", Rth is 4 nm], and the protective film made of triethyl fluorenyl cellulose is bonded to the other side, and the protective film side made of the icyborne resin is attached to the unit cell. In the front side, the retardation plate is disposed such that the slow axis is parallel to the long-axis direction (alignment direction) of the liquid crystal molecules when no voltage is applied to the liquid crystal cell. Further, perpendicular to each absorption axis Way to configure the front The linear polarizing plate and the back side linear polarizing plate. The layer structure and the axial relationship of the liquid crystal display device produced here are as shown in Fig. 4. The contrast change and the color shift of the viewing angle are the same as in Comparative Example 3. "EZ contrast," manufactured by ELDIM. The iso-contrast curves and the x and y chromaticity diagrams are shown in Figures 7 and 8, respectively. In the liquid crystal display device produced in this example, compared with Comparative Example 3, the iso-contrast curve was expanded to the wide viewing angle side, and the color shift due to the viewing angle was small. (Example 7) The evaluation was carried out in the same manner as in Example 6 except that the polarizing plate on the back side was changed to "SRW042A" manufactured by Sumitomo Chemical Co., Ltd. (the Rth of one side of the transparent protective layer was 34 nm). The iso-contrast curve and the x, y chromaticity diagram are divided into 317754 35 1377401 crystal display. Do not show it in Figures 9, 10. The contrast angle of the liquid produced in this example and the color shift due to the viewing angle are also the tilt angles (elevation angles) obtained by comparing 200 with respect to Comparative Example 3 and Examples 6 and 7, and < Read and read azimuth and display the results in Table 2. The azimuth angle 45 is known to the embodiment as compared with the comparative example. -225. Direction, and 135. , _315. The direction of the direction is generally a diffuser. ° [Table 2] ___M It 200 Oblique angle obtained Azimuth angle 0〇 45. 90. 135° 180° 〇9^ ° ----- - Right upper right upper left upper left L· lower left _ 270° lower 315° lower right Comparative example 3 79. 44. 78. 41. >80° 66. >80° 68. Example 6 > 80° 50. 75. 47. >80° > 80β > 80° > 80° Example 7 > 80° 47. 76. 41. >80° 73. >80° 77. And the main conditions in Examples 6 and 7

The results obtained in Comparative Example 3 above are summarized in Table 3. 36 317754 (§) 1377401 [Table 3] Comparative Example__Example 3 6 7 Front side polarizer plate cell side protective layer Rth 52nm 65nm 65nm Cell side protective layer R〇lnm lnm lnm Phase difference plate material*1 PC PS PS Rth -27nm -70nm -70nm R〇135nra 140nm 140nm Nz coefficient 0·3 0.0 0. 0 The sum of the cell side protective layer and the phase difference plate Rth 25nm -5nm -5nm R〇 sum 136nm 141 nm 141nm back Side polarizer cell side protective layer Rth 52nm 4nm 34nm contrast *2 ◎ ◎ ◎ color shift *3 X ◎ ◎ *1 material PS: polystyrene PC: polycarbonate * 2 contrast ◎: good. *3 color deviation ◎: good. X : The color of the diagonal is too large. Comparative Example 4 (a) Preparation of composite polarizing plate The iodine adsorption alignment was applied to the double side of the polarizer of polyvinyl alcohol with 37 317 754 1377401. • The back side illuminates the backlight, and the contrast change and color shift due to the viewing angle are The ''EZ Contrastld: ^, manufactured by ELDIM Co., Ltd.), which is the same as Comparative Example 4, was used. The iso-contrast curves and the X and y chromaticity diagrams due to the viewing angle are shown in Figures 14 and 15 respectively. Although the color shift shown in Fig. 15 is a good result', Fig. 14 shows that the contrast change due to the angle of view is not sufficient. Example 8 In the same manner as in Comparative Example 4, the IPS mode liquid crystal cell 1 〇〇〇 _ 7000 "front surface (visual side) was used, and only the linear polarizing plate was laminated by the acrylic pressure-sensitive adhesive, and on the back surface ( On the backlight side, the composite polarizing plate produced in (a) of Comparative Example 4 was laminated in the order of the unit cell substrate side, the retardation plate, and the linear polarizing plate by an acrylic pressure-sensitive adhesive. The linear polarizing plate is bonded to a single side of a polarizing device that is adsorbed to a polyvinyl alcohol, and has a protective film made of norbornene-based resin, which is an unaligned protective film [〇 tes tes tes tes tes tes tes tes tes tes tes tes tes tes tes tes tes tes tes tes tes Rth is 4 nm], and the protective film made of triethylsulfonyl cellulose is bonded to the other surface, and the protective film side made of the falling ice-borne resin is bonded to the unit cell. The retardation plate on the back side is disposed such that the slow axis is parallel to the long axis direction (alignment direction) of the liquid crystal molecules when no voltage is applied. Further, the front side linear polarizer and the back side linear polarizer are The absorption axis is configured vertically. The layer configuration and the axial relationship of the liquid crystal display device produced in this manner are also as shown in Fig. 11. The backlight is lit by the back surface of the liquid crystal display device, which is the same as the liquid crystal viewing angle manufactured by ELDIM Co., Ltd. The chromaticity-specific J疋 device EZ Contrast'' measures the contrast change and color shift caused by the viewing angle. The equal-contrast curve and the X, y chromaticity diagram due to the viewing angle are not shown in the 16th, the 317754 40 1377401 Figure 17. Compared with Comparative Example 4, the contrast ratio of 2〇〇 is expanded, and the color shift is also small. Example 9 (a) Preparation of composite polarizing plate Preparation of polarized light in polyvinyl alcohol by iodine adsorption alignment A double-sided polarizing plate φ "SR2042A" manufactured by Sumitomo Chemical Co., Ltd., which is made of a transparent protective film made of diethyl fluorene-based cellulose (one piece of Rth is 96 nm and L is 7 nm) is attached to both sides of the apparatus. The protective film side of one side is a fixed-end transverse uniaxially stretched film of polystyrene having a negative intrinsic birefringence, and is 14 〇nm, Rth _92 nm, and a Νζ coefficient by an acrylic pressure-sensitive adhesive. Fit the phase difference plate of _〇2 to make the linear polarization The absorption axis of the plate is perpendicular to the slow axis of the phase difference plate to form a composite polarizing plate. ^ (b) Production and evaluation of the liquid crystal display device In addition to changing the composite polarizing plate on the back side to the one manufactured by the above (a), The evaluation was performed in the same manner as in Example 8. The iso-contrast curves and the χ and y chromaticity diagrams are shown in Figures 18 and 19, respectively. In this example, the contrast change and the color shift due to the viewing angle are also good. Example 1 0 (a) Preparation of composite polarizing plate A transparent protective film made of diethyl fluorinated cellulose was attached to both sides of a polarizer of polyvinyl alcohol in an iodine adsorption alignment (Rth of the Moon) a linear polarizing plate of 1 nm). On the other side of the protective film side, a thickness-aligned phase difference plate made of k polysulfate has an h-type of 80 nm, an Rth of _36 nm, and an Nz coefficient by an acrylic pressure-sensitive adhesive. For the 3173 phase 317754 positive 1377401 difference plate is attached, so that the absorption axis of the linear polarizing plate is perpendicular to the slow axis of the phase difference plate, and a composite polarizing plate is prepared. (b) Production and Evaluation of Liquid Crystal Display Device The evaluation was carried out in the same manner as in Example 8 except that the composite polarizing plate on the back side was changed to the one produced in the above (a). The iso-contrast curves and the X and y chromaticity diagrams generated by the angle of view are shown in Figures 2 and 21, respectively. Compared to Comparative Example 5, the contrast curve of Comparative 200 was expanded.

For the above Comparative Examples 4 and 5 and Examples 8 to 丨〇, the inclination angle (elevation angle) obtained by comparing 200 by the equivalence curve was every 45. The azimuth is read and the results are shown in Table 4. Compared with the comparative example, the example shows that the azimuth angle is 45° and -99[. ± & n directions, and 135. The perspective is generally a diffuser. [Table 4] -315β direction Azimuth angle _r Right 45 Comparative Example 78 47. Lan ^ 匕 200 g to get the tilt angle of the upper right ‘ yu 180. 225. 270° 31~? Up Top Left Left Left Down • - x tJ_ bottom right 80. 54. 75. 57. >80° 55. 79 48 55 Comparative Example > 80 47. 80° 48 > 80 8 > 80° 47. 78. 80. >80° > 80° > 80. Example 9 > 80° 47. 79. >80. >80° > 80° > 80. Example 10 > 80° 79. 78. 76° > 80° 79. >80. 57. 67. >80 317754 42 1377401 • The results obtained in Comparative Examples 4 and 5 and the main conditions in Examples 8 to 10 are summarized in Table 5. [Table 5] Comparative Example 4 4 8 9 10 Rth cell side protective layer of the front side polarizing plate cell side protective layer R 〇 51 nm lnm 5 lnm lnm 4 nm Onra 4 nm Onm 4 nm Onm Back side polarizing plate cell side Protective layer Rth 65nm 5 lnm 65nm 96nm 5 lnm Cell side protective layer R〇lnm lnm lnm 7nm lnm Phase difference plate material 11 PS PC PS PS PC Rth -70nm -36nm -70nm -92nm -36nm R〇140nm 180nm 140nm 140nm 180nm Nz coefficient 0. 0 cell side protective layer and phase difference plate 0. 3 0.0 ~0. 2 0. 3 Rth sum -5nm 15nm -5nm 4nm 15nm R 〇 sum 141nm 18 lnm 141nm 147nm 181nm contrast 12 △ Δ ◎ ◎ ◎ color shift 13 X ◎ ◎ ◎ ◎ 43 317754 1 1 material PS: polystyrene PC: polycarbonate * 2 contrast ◎: good. "/7401 △: Light leakage in the oblique direction. Color shift ◎: Good. X · The color of the oblique direction is too large. [Simplified description of the drawing] Fig. 1 shows an example of the liquid crystal display device of the present invention, (A) A schematic diagram showing a longitudinal section of the layer structure, and (B) is a schematic diagram for explaining the axial relationship. Fig. 2 is a negative uniaxial phase difference satisfying the relationship of nz = nx > ny = refractive index ellipse In the oblique view of the volume, (Α) is the state in which the vehicle with the refractive index ellipsoid is placed in the secret direction, and (B) is placed in the horizontal direction with the axis perpendicular to the in-plane axis (Express). In the liquid crystal display device produced in Comparative Example 1, (A) is a schematic cross-sectional view showing a schematic configuration of a layer, and (8) is a perspective view for explaining an axial relationship. Fig. 4 is an embodiment] to 5, Comparative Example 2 In the liquid crystal display device produced in Comparative Example 3 and Examples 6 and 7, (A) is a schematic longitudinal cross-sectional schematic view showing a schematic display layer structure, and (B) is a perspective view showing an axial relationship. Fig. 5 is a view showing A schematic diagram of an iso-contrast curve of the liquid crystal display device produced in Comparative Example 3. Figure 6 is for Comparative Example 3. In the liquid crystal display device, when the color is not black, the y and y chromaticity diagrams are changed at an elevation angle of 60. The seventh graph shows the equal contrast curve of the liquid crystal display device produced in Example 6. Fig. 8 is a diagram showing the y chromaticity diagram when the azimuth angle is changed at an elevation angle of 60 ° for the liquid crystal display device produced in the embodiment 6, in the case of black 317754 44 1377401. A schematic diagram of the stem contrast curve of the liquid crystal display enamel prepared in Example 7. The display of the liquid crystal display in Example 7 is shown in Figure 7.

When black is shown, 'at the elevation angle of 60. The χ, I y chromaticity diagram when the azimuth angle is changed. Fig. 11 is a perspective view showing a liquid crystal display device of Comparative Examples 4 and 5 and Examples 8 to 1 (A) showing a longitudinal section of a schematic display layer structure (B). Fig. 12 is a schematic view showing the acoustic contrast curve of the liquid crystal display and the clothing set produced in Comparative Example 4. Fig. 13 is a diagram showing the m-x, y chromaticity diagram when the azimuth angle is changed at an elevation angle of 60 ° for the liquid 曰 9 颙 not produced in Comparative Example 4. Fig. 14 is a view showing a comparison curve of the liquid crystal display produced in Comparative Example 5. Fig. 15 is a χ, y chromaticity diagram when the liquid crystal produced in Comparative Example 5 is not used, and when black is displayed, the azimuth angle is changed at an elevation angle of 60 °. Fig. 16 is a view showing an isometric comparison curve of the liquid crystal display device produced in Example 8. Fig. 17 is a diagram showing the χ and ^ y degrees when the azimuth angle is changed at an elevation angle of 60 ° for the liquid crystal chip produced in the eighth embodiment. Fig. 18 is a view showing an isochronous curve of the liquid crystal display which was produced in Example 9. Figure 19 is a view of the liquid crystal 翱__ ... which is made in the embodiment 9

317754 45 1377401 When the black is shown, it is at an elevation angle of 60. The χ, γ chromaticity diagram when the azimuth angle is changed. Fig. 20 is a view showing an isochronous curve of the liquid crystal display device produced in Example 10. Fig. 21 is a view showing the liquid crystal display device produced in Example 1 at an elevation angle of 6 显示 when black is displayed. χ, y chromaticity diagram when the azimuth angle is changed 〇 [Main component symbol description] 10 12 20 30 40 51 53 13 52 First polarizing plate 1 b, 22, 23 transparent protective layer 15 Second polarizing plate 25 phase difference Plate 35 composite polarizing plate 50 liquid crystal cell substrate (transparent substrate) liquid crystal layer 55

21 polarizer absorption axis of the first polarizing plate absorption axis of the second polarizing plate slow axis of the phase difference plate IPS mode liquid crystal cell long axis direction of liquid crystal molecules

317754 46

Claims (1)

1377401 乂 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十 十The liquid crystal is sealed with a liquid crystal cell parallel to the substrate and facing substantially the same direction; and a first polarizing plate and a second polarizing plate disposed to sandwich the liquid crystal cell; the liquid crystal display device is applied The change in the voltage of the liquid crystal cell causes the direction of the long axis of the liquid crystal to change in parallel with the surface of the substrate, and is characterized in that: the first polarizer and the liquid crystal cell are disposed between When the refractive index in the in-plane slow axis direction is set to nx, the refractive index in the direction perpendicular to the slow axis is set to ny, and then the refractive index 6 in the thickness direction is again ' (Nx-nz)/(nx_ny) is a phase difference plate having a Nz coefficient in the range of -0.5 to 0, and the phase difference is formed by the polarizer constituting the first polarizing plate to the phase difference plate. Thickness direction of the birefringent layer of the plate The sum of the difference Rth is in the range of -4 〇 nm to +40 nm, and the sum of the plane phase differences Rfl is in the range of 1 〇〇 nm to 20 Onm; and the second polarizing plate is on both sides of the polarizer The transparent protective layer is disposed in the thickness direction of the transparent protective layer on the liquid crystal cell side of the polarizer, and the phase difference Rth is in the range of -1 Onm to +40 nm. 2. The liquid crystal display device of claim 1, wherein the transparent protective layer on the liquid crystal cell side of the first polarizing plate is composed of a thermoplastic cyclic polyolefin resin film. The difference Rth is in the range of -10 nm to HOnm. 317754 (Revised) 47 1377401 1 Patent Application No. 094146920, the entire disclosure of which is incorporated herein by reference. The slow axis is larger than the absorption axis of the first polarizing plate. 4. The liquid crystal display device according to claim 1 or 2, wherein the 'phase difference plate is such that the slow axis and the liquid crystal molecules located on the adjacent transparent substrate surface are not applied with a long axis direction. Configured in a substantially parallel manner. 5. A polarizing plate set for a liquid crystal display device, comprising a composite polarizing plate and a second polarizing plate, wherein the composite polarizing plate is composed of a first polarizing plate and a phase difference plate disposed on one side thereof 'When the refractive index in the in-plane slow axis (S10W axis) direction is nx, the refractive index in the direction perpendicular to the slow axis is ny, and then the refractive index in the thickness direction is (1), The Nz coefficient shown by (nx-nz)/(nx-ny) of the phase difference plate is in the range of -0.5 to 0, and is formed by the polarizer constituting the first polarizing plate to the phase difference plate. The sum of the thickness direction phase differences Rth of the birefringent layer including the phase difference plate is in the range of -40 nm to +40 nm, and the sum of the plane phase differences R 该 is in the range of 10 〇〇 nm to 2 〇〇 nm; The first polarizing plate is provided with a transparent protective layer on both sides of the polarizer, and at least one of the transparent protective layers has a thickness direction phase difference Rth in the range of -10 nm to +40 nm. 317754 (amendment) 48 1377401 1000—800 —BOO —400 —200 —0 Patent Application No. 094146920 Revision of the Replacement Page on June 20, 2011 Figure 6 317754 (Revised) 3 1377401 W COLOR LOCUS {1931 System) 1000 —800 —600 —400 — 200 —0 Patent Application No. 094146920 Issued June 2, 2011 Revision Replacement Page V Figure 8 317754 (Revised Edition > 4 1377401 —600 —0 1000 -800 4ϋΟ •200 Patent Application No. 094146920 Issued June 20, 2011 Revision Replacement Page W COLOR LOCUS (1931 System) 317754 (. Revised Edition) 5 1377401 90 900.0 800.0 800.0 400.0200.0 p.O Patent Application No. 094146920 Correction Replacement Page, June 20, 2011 xy COLOR LOCUS (1931 System) Figure 13 317754 (Revised) 7 1377401 900.0 —800.0 —6〇αο^-400,0 τ-2〇αο —αο Patent Application No. 094146920 Issued June 20, 2011 Revision Replacement Page ^ COLOR LOCUS (1331 System) 317754 (revised edition) 1377401 COLOR LOCUS ί1931 System) Patent Application No. 094146920, June 20, 2011 Revision Correction Page 317754 (Revised) 9 1377401 90 900.0 800.06〇αο 40Q.0 200.00.0 Patent Application No. '094146920 101 June 20曰 Correction Replacement Page ><y COLOR LOCUS 11331 System} 317754 (revised edition) 10 1377401 90 900.0 800.0 600.0 400.0 200.0αο Patent Application No. 094146920 Issued June 20, 2011 Correction Replacement Page xy COLOR LOCUS [1931 System) 317754 (revised edition)