JP4850499B2 - Optical compensation film, polarizing plate, and liquid crystal display device - Google Patents

Description

  The present invention relates to an optical compensation film which can form a liquid crystal display device having excellent display quality in a wide viewing angle range and which controls the phase difference between the front and perspective directions and its wavelength dispersion.

The liquid crystal display device includes a liquid crystal cell and a polarizing plate. The polarizing plate comprises a protective film and a polarizing film, and is obtained by dyeing a polarizing film made of a polyvinyl alcohol film with iodine, stretching, and laminating both surfaces with a protective film. In the transmissive liquid crystal display device, the polarizing plate is attached to both sides of the liquid crystal cell, and one or more optical compensation films may be disposed. In the reflection type liquid crystal display device, a reflection plate, a liquid crystal cell, one or more optical compensation films, and a polarizing plate are arranged in this order.
The liquid crystal cell includes a liquid crystal molecule, two substrates for encapsulating the liquid crystal molecule, and an electrode layer for applying a voltage to the liquid crystal molecule. The liquid crystal cell performs ON / OFF display depending on the alignment state of the liquid crystalline molecules, and can be applied to both transmission and reflection types. TN (Twisted Nematic), IPS (In-Plane Switching), OCB (Optically) Display modes such as Compensatory Bend), VA (Vertically Aligned), ECB (Electrically Controlled Birefringence), and FFS (Fringe Field Switching) have been proposed.

  The optical compensation film is used in various liquid crystal display devices in order to eliminate image coloring and to widen the viewing angle. As the optical compensation film, a stretched birefringent polymer film has been conventionally used. Further, it has been proposed to use an optical compensation film having an optical compensation layer formed of low-molecular or high-molecular liquid crystalline molecules on a transparent support, instead of the optical compensation film made of a stretched birefringent film. Since the liquid crystalline molecules have various alignment forms, the use of the liquid crystalline molecules can realize optical properties that cannot be obtained with a conventional stretched birefringent polymer film. Furthermore, the structure which doubles as a protective film and an optical compensation film by adding birefringence to the protective film of a polarizing plate is also proposed.

  The optical property of the optical compensation film is determined according to the optical property of the liquid crystal cell, specifically, the difference in the display mode as described above. When liquid crystalline molecules are used, optical compensation films having various optical properties corresponding to various display modes of the liquid crystal cell can be produced. Optical compensation films using liquid crystal molecules have already been proposed for various display modes. For example, an optical compensation film for a parallel alignment liquid crystal cell also serves to improve the viewing angle characteristics of the optical compensation of liquid crystal molecules aligned in parallel to the substrate surface and the orthogonal transmittance of a polarizing plate during black display in the absence of voltage. Patent Document 1).

Japanese Patent No. 3342417

  This invention makes it a subject to achieve the following objectives. That is, the present invention relates to an optical compensation film excellent in the phase dispersion between the first optical anisotropic layer and the second optical anisotropic layer, the wavelength dispersion of the front and oblique retardations of the liquid crystal layer of the liquid crystal cell, and the use thereof. It is an object of the present invention to provide a liquid crystal display device that displays a good image with little color change by using the polarizing plate.

Means for solving the problems are as follows. That is,
<1> It consists of at least a first optical anisotropic layer and a second optical anisotropic layer, and the first optical anisotropic layer satisfies at least one of the following mathematical formulas (1) to (3). The optical compensation film is characterized.
1 ≦ Re ₁ 450 (0 °) / Re ₁ 650 (0 °) ≦ 1.25 (1)
1 ≦ Re ₁ 450 (40 °) / Re ₁ 650 (40 °) ≦ 1.25 (2)
1 ≦ Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °) ≦ 1.25 (3)
However, in the above formulas (1) to (3), it was tilted by θ ° with respect to the normal direction with the slow axis of the first optically anisotropic layer as the rotation axis, measured with light of wavelength λ (nm). If the value of the Re retardation value in the state is defined as _{Re 1 λ (θ) (Re} 1 λ (θ) and Re ₁ λ (-θ) are _{different, Re 1 λ (θ)>} Re 1 λ (- The size is determined so that θ).
<2> The optical compensation film according to <1>, wherein the first optically anisotropic layer is made of at least one of a discotic liquid crystal compound and a rod-like liquid crystal compound.
<3> The optical compensation film according to any one of <1> to <2>, wherein the second optically anisotropic layer satisfies at least one of the following formulas (4) to (6).
0.3 ≦ Re ₂ 450 (0 °) / Re ₂ 650 (0 °) ≦ 1.1 (4)
0.3 ≦ Re ₂ 450 (40 °) / Re ₂ 650 (40 °) ≦ 1.1 (5)
0.3 ≦ Re ₂ 450 (−40 °) / Re ₂ 650 (−40 °) ≦ 1.1 (6)
However, in the above formulas (4) to (6), it was tilted by θ ° with respect to the normal direction with the slow axis of the second optical anisotropic layer as the rotation axis, measured with light of wavelength λ (nm). If the value of the Re retardation value in the state is defined as _{Re 2 λ (θ) (Re} 2 λ (θ) and Re ₂ λ (-θ) are _{different, Re 2 λ (θ)>} Re 2 λ (- The size is determined so that θ).
<4> The first optical anisotropic layer and the second optical anisotropic layer according to any one of <1> to <3>, wherein at least one of the following mathematical formulas (7) to (9) is satisfied: This is an optical compensation film.
Re ₁ 450 (0 °) / Re ₁ 650 (0 °)> Re ₂ 450 (0 °) / Re ₂ 650 (0 °) (7)
Re ₁ 450 (40 °) / Re ₁ 650 (40 °)> Re ₂ 450 (40 °) / Re ₂ 650 (40 °) (8)
Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °)> Re ₂ 450 (−40 °) / Re ₂ 650 (−40 °) (9)
<5> The optical compensation film according to any one of <1> to <4>, wherein the second optically anisotropic layer is made of a cellulose acylate film.

  <6> A polarizing plate comprising a polarizing film and the optical film according to any one of <1> to <5> on at least one side of the polarizing film.

<7> A liquid crystal display device comprising the liquid crystal cell and the polarizing plate according to <6>.
<8> The liquid crystal display device according to <7>, wherein the liquid crystal layer of the liquid crystal cell has optical characteristics satisfying at least one of the following formulas (10) to (12).
1 ≦ Re ₁ c450 (0 °) / Re ₁ c650 (0 °) ≦ 1.25 Formula (10)
1 ≦ Re ₁ c450 (40 °) / Re ₁ c650 (40 °) ≦ 1.25 Formula (11)
1 ≦ Re ₁ c450 (−40 °) / Re ₁ c650 (−40 °) ≦ 1.25
Formula (12)
However, the Re retardation value in a state in which the fast axis of the liquid crystal cell measured with light of wavelength λ (nm) is tilted by θ ° with respect to the normal direction with the axis of rotation as the rotation axis is defined as Re ₁ cλ (θ) ( When the values of Re ₁ cλ (θ) and Re ₁ cλ (−θ) are different, the magnitude is determined so that Re ₁ cλ (θ)> Re ₁ cλ (−θ).
<9> Any one of <7> to <8>, wherein the first optical anisotropic layer and the liquid crystal layer of the liquid crystal cell have optical characteristics satisfying at least one of the following formulas (13) to (15): It is a liquid crystal display device as described in above.
0.9 <{(Re ₁ c450 (0 °) / Re ₁ c650 (0 °)) / (Re ₁ 450 (0 °) / Re ₁ 650 (0 °))} <1.1 Formula (13)
0.9 <{(Re ₁ c450 (40 °) / Re ₁ c650 (40 °)) / (Re ₁ 450 (40 °) / Re ₁ 650 (40 °))} <1.1 Formula (14)
0.9 <{(Re ₁ c450 (−40 °) / Re ₁ c650 (−40 °)) / (Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °))} <1.1 (15)
<10> The liquid crystal display device according to any one of <7> to <9>, wherein the liquid crystal cell is any one of OCB, TN, ECB, IPS, and FFS.

  According to the present invention, an optical compensation film excellent in the phase difference between the first optical anisotropic layer and the second optical anisotropic layer, the wavelength dispersion of the front and oblique retardations of the liquid crystal layer of the liquid crystal cell, and the same are used. By using the polarizing plate and the polarizing plate, it is possible to provide a liquid crystal display device that displays a good image with little color change.

(Optical compensation film)
The optical compensation film of the present invention is an optical compensation film having at least a first optical anisotropic layer and a second optical anisotropic layer.
In the optical compensation film, the average orientation of the inclined liquid crystalline molecules in the vicinity of the interface of the substrate in the liquid crystal display device changes depending on the angle to be observed, that is, the transmittance and brightness change due to the change in viewing angle. There is a function of improving the viewing angle dependency problem by compensating for the residual phase difference of the liquid crystal layer in the vicinity of the substrate interface. By disposing the optical compensation film of the present invention at the substrate interface of the liquid crystal display device, the viewing angle dependency is improved, a complete black display is obtained, and the front contrast ratio is improved.
The viewing angle dependency of the optical compensation film of the present invention is improved by the mutual optical characteristics of the first optical anisotropic layer and the second optical anisotropic layer.

<First optical anisotropic layer>
The first optical anisotropic layer may be designed to compensate for the optical characteristics of the liquid crystal compound in the liquid crystal cell in black display of a liquid crystal display device, and may be directly formed on the surface of the second optical anisotropic layer. Alternatively, an alignment film may be formed on the second optically anisotropic layer and formed on the alignment film.

-Optical characteristics of the first optical anisotropic layer-
The first optically anisotropic layer is generated in a normally black mode TN type liquid crystal display device because the refractive index anisotropy of the liquid crystal layer has wavelength dispersion characteristics (wavelength dependence). There is a function to improve the problem that the black display is colored.
In order to have the function, it is preferable that the first optically anisotropic layer satisfies at least one of the following mathematical formulas (1) to (3).
1 ≦ Re ₁ 450 (0 °) / Re ₁ 650 (0 °) ≦ 1.25 (1)
1 ≦ Re ₁ 450 (40 °) / Re ₁ 650 (40 °) ≦ 1.25 (2)
1 ≦ Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °) ≦ 1.25 (3)
However, in the above formulas (1) to (3), a state in which the slow axis of the first optical anisotropic layer measured with light of wavelength λ (nm) is inclined by θ ° with respect to the normal direction with the slow axis as the rotation axis Is defined as Re ₁ λ (θ) (when Re ₁ λ (θ) and Re ₁ λ (−θ) are different from each other), Re ₁ λ (θ)> Re ₁ λ (−θ ) Decide the size so that.

As represented by the formula (1), the wavelength dispersion of the front retardation of the first optical anisotropic layer is 1 ≦ Re ₁ 450 (0 °) / Re ₁ 650 (0 °) ≦ 1.25. , Re ₁ 450 (0 °) / Re ₁ 650 (0 °) ≦ 1.2, more preferably Re ₁ 450 (0 °) / Re ₁ 650 (0 °) ≦ 1.18. preferable.
When the wavelength dispersion Re ₁ 450 (0 °) / Re ₁ 650 (0 °) is less than 1 or exceeds 1.25, the front color and contrast may be deteriorated.
As represented by the formula (2), the wavelength dispersion of retardation when tilted at 40 ° around the slow axis is 1 ≦ Re ₁ 450 (40 °) / Re ₁ 650 (40 °) ≦ 1. .25 is preferable, and 1 ≦ Re ₁ 450 (40 °) / Re ₁ 650 (40 °) ≦ 1.18 is more preferable.
When the wavelength dispersion Re ₁ 450 (40 °) / Re ₁ 650 (40 °) is less than 1 or exceeds 1.25, the oblique color and viewing angle may be deteriorated.
As expressed by the mathematical formula (3), the retardation wavelength dispersion when tilted at −40 ° about the slow axis is 1 ≦ Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °). ) ≦ 1.25, preferably 1 ≦ Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °) ≦ 1.18.
When the wavelength dispersion Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °) is less than 1 or exceeds 1.25, the oblique color and viewing angle may be deteriorated.
The first optically anisotropic layer preferably satisfies at least two of the formulas (1), (2) and (3), and more preferably satisfies all. Moreover, it is particularly preferable to set appropriately depending on the wavelength dispersion of the retardation of the liquid crystal in the liquid crystal cell.
By satisfying all the formulas (1) to (3), the front and oblique viewing angles, the color tone, and the effect of improving the contrast are remarkably obtained.
The first optical anisotropic layer is preferably designed so as to compensate for the optical characteristics of the liquid crystal compound in the liquid crystal cell in the black display of the liquid crystal display device. The alignment state of the liquid crystal compound in the liquid crystal cell is described in IDW'00, FMC7-2, P411 to 414.

  The material for the first optically anisotropic layer of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the first optically anisotropic layer is preferably formed of a liquid crystal compound, and is preferably formed of a discotic liquid crystal compound and a rod-like material. More preferably, it is formed from at least one of liquid crystal compounds. The first optically anisotropic layer may be directly formed on the surface of the second optically anisotropic layer, and an alignment film is formed on the second optically anisotropic layer and formed on the alignment film. Also good.

-Liquid crystalline compounds-
The liquid crystal compound preferably exhibits a liquid crystal phase exhibiting good monodomain properties. By making the monodomain property favorable, it is possible to effectively prevent the obtained structure from becoming a polydomain and causing an alignment defect at the boundary between domains to scatter light. Furthermore, it is preferable to exhibit good monodomain properties because the retardation plate has a higher light transmittance.

  Examples of the liquid crystal phase expressed by the liquid crystal compound used in the present invention include a columnar phase and a discotic nematic phase (ND phase). Among these liquid crystal phases, a discotic nematic phase (ND phase) that exhibits a good monodomain property and is capable of hybrid alignment is most preferable.

  The liquid crystal compound used in the present invention is better as the anisotropic wavelength dispersion is smaller. Specifically, Re (450) / Re (650) is preferably 1.25 or less, and more preferably 1.20 or less, where Re (λ) is a phase difference expressed by the liquid crystal compound. 1.15 or less is particularly preferable. This value is preferably optimized as appropriate by the wavelength dispersion of the phase difference of the liquid crystal in the cell.

  In the hybrid alignment, the angle between the physical symmetry axis of the liquid crystal compound of the present invention and the surface of the support, that is, the tilt angle, is the depth of the optically anisotropic layer (that is, perpendicular to the (transparent) support). ) Direction and increases or decreases with increasing distance from the plane of the polarizing film. The angle preferably decreases with increasing distance. Further, the change in the inclination angle can be continuous increase, continuous decrease, intermittent increase, intermittent decrease, change including continuous increase and continuous decrease, or intermittent change including increase and decrease. . The intermittent change includes a region where the inclination angle does not change in the middle of the thickness direction. Even if a region where the angle does not change is included, it may be increased or decreased as a whole. However, it is preferred that the tilt angle changes continuously.

In general, the average direction of the physical symmetry axis of the discotic liquid crystalline compound can be adjusted by selecting the discotic liquid crystalline compound, the material of the alignment film, or the rubbing treatment method. Further, the physical symmetry axis direction of the surface side (air side) discotic liquid crystalline compound can be adjusted by selecting the discotic liquid crystalline compound or the kind of additive used together with the discotic liquid crystalline compound. it can.
Examples of the additive used together with the discotic liquid crystalline compound include a plasticizer, a surfactant, a polymerizable monomer, a polymer, and a low molecular compound. The degree of change in the orientation direction of the major axis can be adjusted by selecting the liquid crystalline compound and the additive as described above.

  The plasticizer and polymerizable monomer used together with the liquid crystalline compound of the present invention are compatible with the liquid crystalline compound of the present invention and can change the tilt angle of the discotic liquid crystalline compound or inhibit the alignment. What is not used is adopted.

Specifically, the surfactant is preferably a fluorine compound. Surfactants are described in JP-A No. 2001-330725.
As the polymer and the low-molecular compound, a compound that changes the tilt angle of the discotic liquid crystal compound is preferable. Specifically, cellulose ester is preferable as the polymer. The cellulose ester is described in paragraph [0178] of JP-A No. 2000-155216. The addition amount of the polymer is preferably 0.1 to 10% by mass, and preferably 0.1 to 8% by mass with respect to the discotic liquid crystal compound so as not to inhibit the orientation of the discotic liquid crystal compound. Is more preferable.

  The liquid crystalline compound used in the present invention preferably exhibits a liquid crystal phase in the range of 20 to 300 ° C, more preferably 40 to 280 ° C, and particularly preferably 60 to 250 ° C. Here, the expression of the liquid crystal phase at 20 to 300 ° C. means that the liquid crystal temperature range extends over 20 ° C. (specifically, for example, 10 to 22 ° C.) or the temperature range of 300 ° C. (specifically, for example, 298 to 310). (° C.). The same applies to 40 to 280 ° C and 60 to 250 ° C.

The first optically anisotropic layer can be formed by applying a discotic liquid crystal compound and, if necessary, a coating liquid containing a polymerizable initiator and an optional component described later on the alignment film.
As a solvent used for the preparation of the coating solution, an organic solvent is preferable. Examples of the organic solvent include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, Preferred examples include chloroform (dichloromethane, tetrachloroethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane) and the like. Of these, alkyl halides and ketones are preferred. These organic solvents may be used individually by 1 type, and may use 2 or more types together.

  The coating solution can be applied by a known method (eg, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

  The aligned discotic liquid crystal compound can be fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. Among these, a photopolymerization reaction is preferable. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatics. Group acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketone (US patents) No. 3549367), acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (described in U.S. Pat. No. 4,221,970).

The amount of the photopolymerization initiator used is preferably in the range of 0.01 to 20% by mass, more preferably in the range of 0.5 to 5% by mass, based on the solid content of the coating solution. It is preferable to use ultraviolet rays for light irradiation for polymerization of liquid crystalline molecules. The irradiation energy is preferably 20~50J / cm ^2, more preferably ^{20~5,000mJ / cm 2, 100~800mJ / cm} 2 is particularly preferred. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. A protective layer may be provided on the first optically anisotropic layer.

-Discotic liquid crystal compounds-
The discotic liquid crystal compound may be a high-molecular liquid crystal or a low-molecular liquid crystal, and further includes those in which the low-molecular liquid crystal is cross-linked and no longer exhibits liquid crystallinity.

  Examples of the discotic liquid crystal compound include C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physics Lett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and the cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. , 1794 (1985), J. Am. Zhang et al., J. Am. Chem. Soc. 116, 2655 (1994), azacrown type and phenylacetylene type macrocycles are included.

The discotic liquid crystal compound is a compound having liquid crystallinity in which a linear alkyl group, an alkoxy group or a substituted benzoyloxy group is radially substituted as a side chain of the mother nucleus with respect to the mother nucleus at the center of the molecule. Is also included. The molecule or the assembly of molecules is preferably a compound having rotational symmetry and imparting a certain orientation.
When the first optical anisotropic layer is formed from the discotic liquid crystal compound, the compound finally contained in the first optical anisotropic layer no longer needs to exhibit liquid crystallinity. For example, a low molecular discotic liquid crystal compound has a group that reacts with heat or light, and the group reacts with heat or light to polymerize or crosslink, thereby increasing the molecular weight. In the case where a conductive layer is formed, the compound contained in the first optically anisotropic layer may no longer have liquid crystallinity. Preferred examples of the discotic liquid crystal compound are described in JP-A-8-50206. The polymerization of discotic liquid crystal compounds is described in JP-A-8-27284.

  In order to fix the discotic liquid crystal compound by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystal compound. However, when the polymerizable group is directly connected to the disc-shaped core, it becomes difficult to maintain the orientation state in the polymerization reaction. Therefore, a linking group is introduced between the discotic core and the polymerizable group. Therefore, the discotic liquid crystal compound having a polymerizable group is preferably a compound represented by the following formula (DI).

General formula (DI)

In the general formula (DI), Y ¹¹ , Y ¹² and Y ¹³ each independently represent a methine or a nitrogen atom.

When Y ¹¹ , Y ¹² and Y ¹³ are methine, the hydrogen atom of methine may be substituted with a substituent. Here, methine refers to an atomic group obtained by removing three hydrogen atoms from methane.
Even though the carbon atom of the methine has a substituent, an alkyl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an alkylthio group, an arylthio group, Preferred examples include halogen atoms and cyano groups. Among these substituents, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, a halogen atom and a cyano group are preferable, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and 2 carbon atoms. A -12 alkoxycarbonyl group, a C2-C12 acyloxy group, a halogen atom, and a cyano group are more preferable.
Y ¹¹ , Y ¹² and Y ¹³ are all preferably methine, and methine is more preferably unsubstituted.

In the general formula (DI), L ¹ , L ² and L ³ each independently represent a single bond or a divalent linking group. When L ¹ , L ² and L ³ are divalent linking groups, each independently represents —O—, —S—, —C (═O) —, —NR ⁷ —, —CH═CH—, —C. It is preferably a bivalent linking group selected from the group consisting of ≡C—, a divalent cyclic group, and combinations thereof. R ⁷ is an alkyl group having 1 to ⁷ carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group, or a hydrogen atom. A hydrogen atom is preferable, and a hydrogen atom is particularly preferable.

The divalent cyclic group in L ¹ , L ² and L ³ is a divalent linking group having at least one cyclic structure (hereinafter sometimes referred to as a cyclic group). The cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and particularly preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. Further, the ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Preferred examples of the aromatic ring include a benzene ring and a naphthalene ring. A preferable example of the aliphatic ring is a cyclohexane ring. Preferred examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring. The cyclic group is more preferably an aromatic ring or a heterocyclic ring. The divalent cyclic group in the present invention is more preferably a divalent linking group consisting of only a cyclic structure (including a substituent) (hereinafter the same).

Of the divalent cyclic groups represented by L ¹ , L ² and L ³ , the cyclic group having a benzene ring is preferably a 1,4-phenylene group. As the cyclic group having a naphthalene ring, a naphthalene-1,5-diyl group and a naphthalene-2,6-diyl group are preferable. The cyclic group having a cyclohexane ring is preferably a 1,4-cyclohexylene group. The cyclic group having a pyridine ring is preferably a pyridine-2,5-diyl group. The cyclic group having a pyrimidine ring is preferably a pyrimidine-2,5-diyl group.

The divalent cyclic group represented by L ¹ , L ² and L ³ may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, and 1 to 1 carbon atoms. 16 halogen-substituted alkyl groups, alkoxy groups having 1 to 16 carbon atoms, acyl groups having 2 to 16 carbon atoms, alkylthio groups having 1 to 16 carbon atoms, acyloxy groups having 2 to 16 carbon atoms, carbon atoms Examples include a C 2-16 alkoxycarbonyl group, a carbamoyl group, a carbamoyl group substituted with a C 2-16 alkyl group, and a C 2-16 acylamino group.

L ¹ , L ² and L ³ include a single bond, * —O—CO—, * —CO—O—, * —CH═CH—, * —C≡C—, * —divalent cyclic group. -, * -O-CO-divalent cyclic group-, * -CO-O-divalent cyclic group-, * -CH = CH-divalent cyclic group-, * -C≡C-divalent Cyclic group-, * -Divalent cyclic group-O-CO-, * -Divalent cyclic group-CO-O-, * -Divalent cyclic group-CH = CH- and * -Divalent cyclic group -C≡C- is preferred. In particular, a single bond, * —CH═CH—, * —C≡C—, * —divalent cyclic group —O—CO—, * —CH═CH—divalent cyclic group—, and * —C≡C. -A divalent cyclic group is preferable, and a single bond is more preferable. Here, * represents the position bonded to the 6-membered ring side including Y ¹¹ , Y ¹² and Y ¹³ in the general formula (DI).

H ¹ , H ² and H ³ each independently represent the following general formula (DI-A) or the following general formula (DI-B).

General formula (DI-A)

In the general formula (DI-A), YA ¹ and YA ² each independently represents a methine group or a nitrogen atom. It is preferable that at least one of YA ¹ and YA ² is a nitrogen atom, and it is more preferable that both are nitrogen atoms. XA represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom. * Represents a position bonded to the L ^{1 to} L ³ side in the general formula (DI), and ** represents a position bonded to the R ^{1 to} R ³ side in the general formula (DI). Here, imino means that represented by —NH—.

General formula (DI-B)

In the general formula (DI-B), YB ¹ and YB ² each independently represent a methine or a nitrogen atom. It is preferable that at least one of YB ¹ and YB ² is a nitrogen atom, and it is more preferable that both are nitrogen atoms. XB represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom. * Represents a position bonded to the L ^{1 to} L ³ side in the general formula (DI), and ** represents a position bonded to the R ^{1 to} R ³ side in the general formula (DI).

Said R < ¹ >, R < ² > and R < ³ > represent the following general formula (DI-R) each independently.

General formula (DI-R)
^{* - (- L 21 -Q 2} ) n1-L 22 -L 23 -Q 1

In formula (DI-R), * indicates the position at which the group bonds to ^H 1 to H ³ side in formula (DI).

L ²¹ represents a single bond or a divalent linking group. When L ²¹ is a divalent linking group, from the group consisting of —O—, —S—, —C (═O) —, —NR ⁷ —, —CH═CH—, C≡C—, and combinations thereof. A divalent linking group selected is preferable. R ⁷ is an alkyl group having 1 to ⁷ carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group, or a hydrogen atom. A hydrogen atom is preferable, and a hydrogen atom is particularly preferable.

Specific examples of L ²¹ include a single bond, ***-O-CO-, ***-CO-O-, ***-CH = CH-, and ***-C≡C. -(Here, *** represents the * side in the general formula (DI-R)) is preferable, and a single bond is more preferable.

Q ² represents a divalent group (cyclic group) having at least one kind of cyclic structure. As such a cyclic group, a cyclic group having a 5-membered ring, a 6-membered ring, or a 7-membered ring is preferable, a cyclic group having a 5-membered ring or a 6-membered ring is more preferable, and a cyclic group having a 6-membered ring is Particularly preferred. The cyclic structure contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. Further, the ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Preferred examples of the aromatic ring include a benzene ring and a naphthalene ring. A preferable example of the aliphatic ring is a cyclohexane ring. Preferred examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.

Of Q ^2, the cyclic group having a benzene ring is preferably a 1,4-phenylene group. As the cyclic group having a naphthalene ring, a naphthalene-1,5-diyl group and a naphthalene-2,6-diyl group are preferable. The cyclic group having a cyclohexane ring is preferably a 1,4-cyclohexylene group. The cyclic group having a pyridine ring is preferably a pyridine-2,5-diyl group. The cyclic group having a pyrimidine ring is preferably a pyrimidine-2,5-diyl group. Among these, a 1,4-phenylene group and a 1,4-cyclohexylene group are particularly preferable.

Q ² may have a substituent, and examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), a cyano group, a nitro group, and a carbon atom number of 1 to 16. Alkyl group, alkenyl group having 2 to 16 carbon atoms, alkynyl group having 2 to 16 carbon atoms, alkyl group substituted with halogen having 1 to 16 carbon atoms, alkoxy group having 1 to 16 carbon atoms, carbon atom An acyl group having 2 to 16 carbon atoms, an alkylthio group having 1 to 16 carbon atoms, an acyloxy group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, and an alkyl having 2 to 16 carbon atoms Preferred examples include substituted carbamoyl groups and acylamino groups having 2 to 16 carbon atoms. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are particularly preferable.

  N1 represents an integer of 0 to 4. As n1, the integer of 1-3 is preferable and 1 or 2 is more preferable.

L ²² is **-O-, **-O-CO-, **-CO-O-, **-O-CO-O-, **-S-, **-N (R). _{-, ** - CH 2 -,} ** - CH = CH- and ** - C≡C- (where ** denotes the position at which the group bonds to Q2 side.) represents either.
Among these, as the ^{L 22} is, ** - O -, ** - O-CO -, ** - CO-O -, ** - O-CO-O -, ** - CH 2 -, * **-CH = CH-, **-C≡C- are preferred, **-O-, **-O-CO-, **-O-CO-O-, **-CH ₂ -are more preferred. .

The L ²³ is a group consisting of —O—, —S—, —C (═O) —, —NH—, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. It represents a divalent linking group selected from the above. Here, the hydrogen atoms of —NH—, —CH ₂ —, and —CH═CH— may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy having 1 to 6 carbon atoms. Group, an acyl group having 2 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and 2 carbon atoms A carbamoyl group substituted with -6 alkyl and an acylamino group having 2 to 6 carbon atoms are preferred, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred.

L ²³ is preferably selected from the group consisting of —O—, —C (═O) —, —CH ₂ —, —CH═CH—, C≡C—, and combinations thereof. The L ²³ preferably contains 1 to 20 carbon atoms, more preferably 2 to 14 carbon atoms. Furthermore, the ^{L 23} is, -CH ₂ - preferably contains 1 to 16 a, -CH ₂ - and more preferably a containing 2-12.

Q ¹ represents a polymerizable group or a hydrogen atom. When the liquid crystalline compound used in the present invention is used for an optical compensation film or the like that preferably has a phase difference that does not change due to heat, such as an optical compensation film, Q ¹ is preferably a polymerizable group. The polymerization reaction is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. That is, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

Furthermore, the polymerizable group is particularly preferably a functional group capable of addition polymerization reaction. Such a polymerizable group is preferably a polymerizable ethylenically unsaturated group or a ring-opening polymerizable group.
Examples of the polymerizable ethylenically unsaturated group include the following formulas (M-1) to (M-6).

In the formulas (M-3) and (M-4), R represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.
Among the formulas (M-1) to (M-6), (M-1) or (M-2) is preferable, and (M-1) is more preferable.
The ring-opening polymerizable group is preferably a cyclic ether group, more preferably an epoxy group or oxetanyl group, and particularly preferably an epoxy group.
The liquid crystalline compound used in the present invention is preferably a liquid crystalline compound represented by the following general formula (DII).

Formula (DII)

In the general formula (DII), Y ³¹ , Y ³² and Y ³³ each independently represent a methylene or nitrogen atom and are synonymous with Y ¹¹ , Y ¹² and Y ^{13 in} the general formula (DI), and are preferable. The range is also synonymous.
In the general formula (DII), R ³¹ , R ³² and R ³³ each independently represent the following general formula (DII-R).

General formula (DII-R)

In the general formula (DII-R), A ³¹ and A ³² each independently represent a methylene or nitrogen atom, preferably at least one is a nitrogen atom, and more preferably both are nitrogen atoms. X ³ represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.
Q ³¹ represents a divalent linking group having a 6-membered cyclic structure (hereinafter sometimes referred to as a 6-membered cyclic group). The 6-membered ring may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. The ring contained in the 6-membered cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Preferred examples of the aromatic ring include a benzene ring and a naphthalene ring. A preferable example of the aliphatic ring is a cyclohexane ring. Preferred examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.

Of Q ^31, the 6-membered cyclic group having a benzene ring is preferably a 1,4-phenylene group or a 1,3-phenylene group. As the cyclic structure having a naphthalene ring, a naphthalene-1,5-diyl group and a naphthalene-2,6-diyl group are preferable. The cyclic structure having a cyclohexane ring is preferably a 1,4-cyclohexylene group. The cyclic structure having a pyridine ring is preferably a pyridine-2,5-diyl group. The cyclic structure having a pyrimidine ring is preferably a pyrimidine-2,5-diyl group. Among these, 1,4-phenylene group, 1,4-cyclohexylene group, and 1,3-phenylene group are more preferable.

The cyclic structure of Q ³¹ may have a substituent, and examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a cyano group, a nitro group, and one carbon atom. Alkyl group having 1 to 16 carbon atoms, alkenyl group having 2 to 16 carbon atoms, alkynyl group having 2 to 16 carbon atoms, alkyl group substituted with a halogen atom having 1 to 16 carbon atoms, alkoxy having 1 to 16 carbon atoms Group, an acyl group having 2 to 16 carbon atoms, an alkylthio group having 1 to 16 carbon atoms, an acyloxy group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, and 2 carbon atoms Preferable examples include ˜16 alkyl-substituted carbamoyl groups and acylamino groups having 2 to 16 carbon atoms. Among these, the substituent of the 6-membered cyclic group is preferably a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, or an alkyl group substituted with a halogen atom having 1 to 6 carbon atoms. More preferable are an atom, an alkyl group having 1 to 4 carbon atoms, and an alkyl group substituted with a halogen atom having 1 to 4 carbon atoms, particularly a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group. preferable.
N3 represents an integer of 1 to 3, and preferably 1 or 2.
The L ³¹ is * -O-, * -O-CO-, * -CO-O-, * -O-CO-O-, * -S-, * -N (R)-, * -CH _2. -, * -CH = CH- and * -C≡C- (where * represents a position bonded to the Q31 side), specifically, in the general formula (DI-R) It has the same meaning as L ^22, and the preferred range is also the same.
L ³² is selected from the group consisting of —O—, —S—, —C (═O) —, —NH—, —CH ₂ —, —CH═CH— and C≡C—, and combinations thereof. It represents a divalent linking group selected, specifically, the general formula has the same meanings as (DI-R) in L ^23, and the preferred range is also the same.
Q ³² in the general formula (DII-R) represents a polymerizable group or a hydrogen atom.
Specific examples of the liquid crystal compound represented by the general formula (DI) are shown below, but the present invention is not limited thereto.

-Rod-shaped liquid crystal compound-
The rod-shaped compound preferably has a linear molecular structure. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation is performed using molecular orbital calculation software (for example, WinMOPAC2000, manufactured by Fujitsu Limited), and a molecular structure that minimizes the heat of formation of a compound can be obtained. The molecular structure being linear means that the angle of the molecular structure is 140 degrees or more in the thermodynamically most stable structure obtained by calculation as described above.

The rod-like compound preferably exhibits liquid crystallinity. More preferably, the rod-like compound exhibits liquid crystallinity upon heating (has thermotropic liquid crystallinity). The liquid crystal phase is preferably a nematic phase or a smectic phase.
The compound is described in JP-A No. 2004-4550, but is not limited thereto. Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.

  The rod-like compound can be synthesized with reference to methods described in literature. As said literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989); Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. 40, 420 (1975), Tetrahedron, 48, 16, 3437 (1992).

-Thickness of the first optically anisotropic layer-
There is no restriction | limiting in particular as thickness of the said 1st optically anisotropic layer, According to the objective, it can select suitably, For example, it is preferable that it is 0.1-20 micrometers, and it is 0.3-10 micrometers. Is more preferable, and 0.5 to 5 μm is particularly preferable.

<Second optically anisotropic layer>
The second optically anisotropic layer, together with the first optically anisotropic layer of the present invention, in a normally black mode TN type liquid crystal display device, the refractive index anisotropy of the liquid crystal layer has a wavelength dispersion characteristic (wavelength characteristic). The second optically anisotropic layer has the following formula (4) to (4) to have the function of improving the problem that the black display or the like is colored due to It is preferable to satisfy at least one of (6).
0.3 ≦ Re ₂ 450 (0 °) / Re ₂ 650 (0 °) ≦ 1.1 (4)
0.3 ≦ Re ₂ 450 (40 °) / Re ₂ 650 (40 °) ≦ 1.1 (5)
0.3 ≦ Re ₂ 450 (−40 °) / Re ₂ 650 (−40 °) ≦ 1.1 (6)
However, in the above formulas (4) to (6), a state in which the slow axis of the second optical anisotropic layer measured with light of wavelength λ (nm) is inclined by θ ° with respect to the normal direction with the slow axis as the rotation axis Is defined as Re ₂ λ (θ) (when Re ₂ λ (θ) and Re ₂ λ (−θ) are different from each other), Re ₂ λ (θ)> Re ₂ λ (−θ ) Decide the size so that.
The second optically anisotropic layer preferably satisfies at least two of (4), (5) and (6), and more preferably satisfies all.

The front retardation of the second optically anisotropic layer is preferably 30 ≦ Re ₂ 550 (0 °) ≦ 60, and more preferably 30 ≦ Re ₂ 550 (0 °) ≦ 55.
The thickness direction retardation of the second optically anisotropic layer is preferably 100 ≦ Rth ₂ 550 (0 °) ≦ 300, and more preferably 120 ≦ 100 ≦ Rth ₂ 550 (0 °) ≦ 250. .
It is preferable that the front retardation and the thickness direction retardation of the second optically anisotropic layer are appropriately optimized depending on Δn of the liquid crystal of the cell and the cell gap d. As at least one of Δn and cell gap d of the cell liquid crystal increases, the front retardation of the second optical anisotropic layer is preferably small and the thickness direction retardation is preferably large.

There is no restriction | limiting in particular as a material of a said 2nd optically anisotropic layer, According to the objective, it can select suitably, For example, a polymer film is preferable. Specific examples of the polymer film include norbornene polymers, polycarbonate polymers, polyarylate polymers, polyester polymers, aromatic polymers such as polysulfone, triacetyl cellulose, and cellulose acylate films. The thing which can be formed into a film by a solution casting method and an extrusion method is mentioned. Among these, a cellulose acylate film is preferable.
The cellulose acylate film will be specifically described below.

-Wavelength dispersion control of cellulose acylate film-
The cellulose acylate film is known to have different wavelength dependency of Re or Rth depending on the degree of substitution (proportional to the acylate ratio). As the degree of substitution increases, Re (Rth) tends to decrease on the short wavelength side and Re (Rth) increases on the long wavelength side. In the present invention, the substitution degree of cellulose acylate is varied in the range of 2.00 to 3.00 in the thickness direction of the film by 0.05 or more. The fluctuation range is preferably 0.07 or more, more preferably 0.08 or more, further preferably 0.09 or more, and particularly preferably 0.10 or more.

  In general, the cellulose acylate film is preferably produced by a solution casting method, and more preferably the residual solvent is stretched between 2 and 100% by mass. These specific examples will be described in detail later. The present inventor has analyzed the stretched film and found that the stretch orientation degree of the cellulose acylate molecules is different in the thickness direction. Specifically, as compared with the inside of the film, the stretching orientation degree increases toward the outside. This is presumed that the residual solvent stays inside the film, and orientation relaxation occurs even if the inside of the film is stretched, and as a result, the degree of stretch orientation on the outside increases.

  When a layer having a high degree of substitution (acylation rate) is provided on the outside of the cellulose acylate film and a layer having a low degree of substitution (acylation rate) is provided on the inside, and stretching is performed in a state having a residual solvent, it is expressed by stretching. The Re value is greatly influenced by the layer with a high degree of substitution (acylation rate) that is the outer layer of the film, and the Rth value is influenced by the entire film due to the plane orientation due to the decrease in the thickness of the entire film as the drying proceeds. Receive. Therefore, films having different wavelength dependences of the Re value and the Rth value can be produced. The outer substitution degree is 2.71 to 3.00 (acetation ratio in the case of cellulose acetate is 59.0 to 62.5%), and the inner substitution degree is 2.56 to 2.87 (in the case of cellulose acetate). The acetate ratio is preferably 57.0 to 61.0%), the outside is preferably 2.75 to 2.92 (59.5 to 61.5%), and the inside is 2.64 to 2.83 (58.58%). 0 to 60.5%) is preferable. When the thickness is 1, the outer ratio is preferably 0.01 to 0.5, and more preferably 0.05 to 0.4. The absolute values of Re and Rth and the wavelength dependence can be appropriately controlled by the additives described later.

In this specification, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at wavelength λ.
Re (λ) is measured in KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) by making light having a wavelength of λ nm incident in the normal direction of the film.
Rth (λ) is the wavelength of λnm from the direction inclined by + 40 ° with respect to the normal direction of the film, with Re (λ) and the in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotation axis). Retardation value measured by making light incident, and retardation measured by making light of wavelength λ nm incident from a direction inclined by -40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis) KOBRA 21ADH calculates based on retardation values measured in a total of three directions.
Here, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. If the average refractive index is not known, it can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). The KOBRA 21ADH can calculate nx, ny, and nz by inputting the assumed average refractive index and the film thickness.

  The ratio Re / Rth (450) of Re and Rth at a wavelength of 450 nm in the visible light region of the cellulose acylate film is 0.4 to 0.95 times Re / Rth (550) at a wavelength of 550 nm; 4 to 0.9 times are preferable, 0.6 to 0.8 times are more preferable, and Re / Rth (650) at a wavelength of 650 nm is 1.05 to 1.93 times Re / Rth (550). 1.1 to 1.9 times is preferable, and 1.2 to 1.7 times is more preferable. In addition, it is preferable that Re / Rth in each of the wavelength 450 nm, the wavelength 550 nm, and the wavelength 650 nm is in the range of 0.1 to 0.8.

  Since the retardation (Rth) in the thickness direction of the entire cellulose acylate film has a function for canceling the retardation of the liquid crystal layer in the thickness direction during black display, the preferred range varies depending on the mode of each liquid crystal layer. For example, the optical characteristics of an OCB mode liquid crystal cell (for example, an OCB mode liquid crystal cell having a liquid crystal layer having a product Δn · d of thickness d (μm) and refractive index anisotropy Δn of 0.2 to 1.5 μm). When used for compensation, it is preferably 70 to 400 nm, more preferably 100 to 400 nm, and particularly preferably 160 to 300 nm. The Re retardation is generally 20 to 110 nm, preferably 20 to 70 nm, and more preferably 35 to 70 nm.

-Cellulose acylate-
There is no restriction | limiting in particular as raw material cotton used as the material of the said cellulose acylate, According to the objective, it can select suitably, For example, a well-known raw material can be used (for example, refer to the invention association open technique 2001-1745). ). Cellulose acylate can also be synthesized by a known method (for example, see Mita et al., Wood Chemistry pages 180-190 (Kyoritsu Shuppan, 1968)). The viscosity average polymerization degree of cellulose acylate is preferably 200 to 700, more preferably 250 to 500, and particularly preferably 250 to 350. The cellulose ester used in the present invention preferably has a narrow molecular weight distribution of Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. The specific value of Mw / Mn is preferably 1.5 to 5.0, more preferably 2.0 to 4.5, and particularly preferably 3.0 to 4.0. preferable.

  The acyl group of the cellulose acylate is not particularly limited, but an acetyl group or a propionyl group is preferably used, and an acetyl group is particularly preferable. The degree of substitution of all acyl groups is preferably 2.7 to 3.0, more preferably 2.8 to 2.95. In this specification, the substitution degree of an acyl group is a value calculated according to ASTM D817. The acyl group is most preferably an acetyl group, and when cellulose acetate having an acyl group as the acetyl group is used, the degree of acetylation is preferably 57.0 to 62.5%, and 58.0 to 61.5. % Is more preferable. When the acetylation degree is within this range, Re does not become larger than a desired value due to the conveying tension during casting, there is little in-plane variation, and there is little change in the retardation value due to temperature and humidity. In addition, the substitution degree of the acyl group at the 6-position is preferably 0.9 or more from the viewpoint of suppressing variations in Re and Rth.

-Co-casting method-
The co-casting method is suitable for producing cellulose acylate films having different acylation rates in the thickness direction of the present invention.
In the co-casting method, it is preferable to cast a plurality of cellulose acylate liquids of two or more layers on the obtained cellulose acylate solution on a smooth band or drum as a metal support.

  Of the co-casting methods, when a multilayer casting film or a multilayer film is manufactured by using a liquid casting method, a feed block type casting die is often used. This is a casting apparatus in which joining means for joining two or more kinds of dopes is joined to the upstream side of the casting die. A typical structure of the feedblock type casting die is provided with a flow path through which a dope serving as a core layer is passed in the center, and a dope forming a surface layer on the front side and a surface layer on the back side is passed on both sides thereof, and The latter two solution streams are joined to both sides of the former solution stream. As an example of a method for producing a multilayer film using the above feed block type casting die, a relatively high viscosity dope is used for the resin layer as the core layer, and a relatively low viscosity dope is used for the front and back surface layers. Japanese Patent Publication No. 62-43846 discloses a method of performing dry peeling after forming a multilayer cast film.

  On the other hand, when casting a plurality of cellulose acylate solutions, a film is formed while laminating a solution containing cellulose acylate from a plurality of casting openings provided at intervals in the traveling direction of the metal support. For example, the methods described in JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be applied. Alternatively, a film may be formed by casting a cellulose acylate solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245 It can be carried out by the methods described in JP-A Nos. 61-104813, 61-158413, and 6-134933. Further, a cellulose acylate film in which a flow of a high-viscosity cellulose acylate solution described in JP-A-56-162617 is wrapped with a low-viscosity cellulose acylate solution and the high- and low-viscosity cellulose acylate solutions are simultaneously extruded. A casting method may be used. Furthermore, it is also preferable that the outer solution described in JP-A-61-94724 and JP-A-61-94725 contains a larger amount of an alcohol component which is a poorer solvent than the inner solution. is there.

Alternatively, by using two casting ports, the film cast on the metal support by the first casting port is peeled off, and the second casting is performed on the side that is in contact with the metal support surface, thereby forming the film. For example, it is a method described in Japanese Patent Publication No. 44-20235. The cellulose acylate solutions to be cast may be the same solution or different cellulose acylate solutions, and are not particularly limited. In order to give a function to a plurality of cellulose acylate layers, a cellulose acylate solution corresponding to the function may be extruded from each casting port.
Furthermore, the cellulose acylate solution of the present invention may be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorbing layer, a polarizing layer, etc.). .

  In the conventional single-layer liquid, it is necessary to extrude a cellulose acylate solution having a high concentration and a high viscosity in order to obtain a necessary film thickness. In many cases, the problem occurs, such as a failure or flatness. As a solution to this, by casting a plurality of cellulose acylate solutions from a casting port, a highly viscous solution can be extruded onto a metal support at the same time. Not only can it be produced, but also a concentrated cellulose acylate solution can be used to reduce the drying load and increase the film production speed.

  In the case of the co-casting method, a cellulose acylate film having a laminated structure is prepared by co-casting cellulose acylate solutions having different additive concentrations such as a plasticizer, an ultraviolet absorber, and a matting agent described later in addition to the acylation ratio. Can also be produced. For example, a cellulose acylate film having a structure of skin layer / core layer / skin layer can be produced. For example, the matting agent can be contained in the skin layer in a large amount or only in the skin layer. The plasticizer and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer. It is also possible to change the type of plasticizer and ultraviolet absorber between the core layer and the skin layer. For example, the skin layer contains at least one of a low-volatile plasticizer and an ultraviolet absorber, and the core layer is plastic. It is also possible to add an excellent plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. Moreover, it is also a preferable aspect that a release agent is contained only in the skin layer on the metal support side. It is also preferable to add more alcohol, which is a poor solvent, to the skin layer than the core layer in order to cool the metal support by the cooling drum method to gel the solution. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer. In addition, the viscosity of the solution containing cellulose acylate during casting may be different between the skin layer and the core layer, and the viscosity of the skin layer is preferably smaller than the viscosity of the core layer. It may be smaller than the viscosity.

  Further, the casting method according to the present invention will be described in detail. A method of uniformly extruding the prepared dope from a pressure die onto a metal support, and a film thickness of the dope once cast on the metal support with a blade There are a method using a doctor blade for adjusting the pressure, a method using a reverse roll coater for adjusting with a reverse rotating roll, etc., but a method using a pressure die is preferred. The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods mentioned here, various methods for casting a cellulose triacetate solution known in the art (for example, JP-A-61-94724, JP-A-61-148013, JP-A-4). -85011, JP-A-4-286611, JP-A-5-185443, JP-A-5-185445, JP-A-6-278149, JP-A-8-207210, etc. The above method can be preferably used, and the same effects as described in the respective publications can be obtained by setting each condition in consideration of the difference in the boiling point of the solvent used.

  In addition, as an invention related to the co-casting method, in order to increase the casting speed, Japanese Patent Application Laid-Open No. 53-134869 discloses that the cellulose acetate solution is 10-90 to the total film thickness from the first casting port. % Of the film thickness is cast, and the remainder is cast from the second casting port at a distance of 30 to 60% from the first casting port to peeling. Japanese Patent Application Laid-Open No. 61-018943 discloses a dope (A) composed of METIC and methanol and another poor solvent in order to speed up casting stably, and a dope in which the ratio of the poor solvent is higher than A. In (B), an invention is described in which dope A is co-cast and formed into a film so as to be 5 μm or more in an undried state. Furthermore, it is also disclosed that it is desirable to join A and B in the middle of the slit with a composite slit die. This invention has the same effect even if the methylochrome is non-chlorine, and can be applied to the present invention.

  Furthermore, for the purpose of obtaining a magnetic recording layer with good flatness, Japanese Patent Application Laid-Open No. 4-124645 discloses a stripe co-casting in which the sectional name of the slit from one manifold to the merge portion is a comb-like shape. An invention using a die is described.

  Moreover, in order to reduce the solvent contained in the film immediately after production with excellent transparency, dimensional stability, and heat and humidity resistance, JP-A-8-207210 discloses a cellulose acetate having a substitution degree ≦ 2.7. An invention is described in which a core portion and a surface layer having a thickness of 0.5 to 15 μm made of cellulose acetate having a substitution degree ≧ 2.8 are described on at least one surface of the core portion.

  Further, in JP-A-10-058514, in order to prevent the film from being peeled off with good smoothness, the surface layer dope is coated on the base layer dope (excluding both ends) and simultaneously extruded from the die. An invention for extending is described. JP-A-5-040321 discloses an invention relating to a light-sensitive material obtained by co-casting magnetic dope and non-magnetic dope.

  Furthermore, in order to obtain a multilayer resin film with high thickness accuracy, Japanese Patent Application Laid-Open No. 2000-317960 discloses that a low viscosity liquid and a high viscosity liquid with a viscosity 2-10 times higher than that are fed from each flow path. An invention is described in which a multi-layer cast film is formed by discharging from a casting die lip in 5-25 seconds from the time of merging after merging with an apparatus and forming a liquid parallel flow in contact with the interface.

  Japanese Patent Application Laid-Open No. 2002-221620 discloses that the slope of streaky unevenness having a pitch of 3 to 15 mm is less than 0.04 degrees by co-casting the outer layer of the polarizing plate with a low concentration. It is described that.

  Furthermore, in Japanese Patent Application Laid-Open No. 2003-080541, a dope shear viscosity A and an intermediate layer are formed to form a front surface or a back surface layer when casting a plurality of dopes from a die in order to suppress generation of burrs. An invention is described in which the ratio A / B to the shear viscosity B of the dope is A / B ≦ 0.9.

  Further, JP-A-2003-014933 discloses an invention of a retardation film having little additive bleed-out, no delamination phenomenon between layers, excellent slipperiness and excellent transparency.

  Furthermore, in Japanese Patent Application Laid-Open No. 2003-014933, it is preferable to add fine particles to the surface layer in order to impart film slipperiness, and it is not necessary to add fine particles to the core layer, but they may be added. It is disclosed. However, since the transparency of the film deteriorates when the amount of fine particles added to the core layer is large, the amount added is preferably 1/10 or less of the amount added of the surface layer. It is shown not to include. (Substantially not contained, the amount of fine particles added is 0 to 0.01% by mass per solid content) It is also disclosed that the effect of slipperiness can be obtained if blended on at least one side of both surface layers. In particular, the primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 16 to 5 nm, and particularly preferably 12 to 5 nm, from the viewpoint of keeping the haze low. The apparent specific gravity of the fine particles is preferably 70 g / liter or more, more preferably 90 to 200 g / liter, and particularly preferably 100 to 200 g / liter. It is described that the higher the apparent specific gravity is, the higher the concentration of the dispersion liquid can be made, and the haze and aggregates are improved. Here, the silicon dioxide fine particles having an average primary particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more are, for example, 1,000 to 1,200 obtained by mixing vaporized silicon tetrachloride and hydrogen. It can be obtained by burning in air at ℃. Moreover, it is disclosed that it is marketed with the brand name of Aerosil 200V, Aerosil R972V (above, Nippon Aerosil Co., Ltd. product), for example.

-Stretching-
The cellulose acylate film of the present invention exhibits a function by stretching. The cellulose acylate film of the present invention is preferably stretched in the width direction when applied to a polarizing plate. For example, it is described in JP-A-62-115035, JP-A-4-152125, JP-A-4-284221, JP-A-4-298310, JP-A-11-48271, and the like. Yes. The film is stretched at room temperature or under heating conditions. The heating temperature is preferably not higher than the glass transition temperature of the film. The film may be stretched uniaxially or biaxially. The film can be stretched by a treatment during drying, and is particularly effective when the solvent remains. For example, the film is stretched by adjusting the speed of the film transport roller so that the film winding speed is higher than the film peeling speed. The film can also be stretched by conveying the film while holding it with a tenter and gradually increasing the width of the tenter. After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine). The stretch ratio of the film (ratio of increase due to stretching relative to the original length) is preferably 0.5 to 300%, more preferably 1 to 200%, and particularly preferably 1 to 100%. . The cellulose acylate film of the present invention is preferably produced by sequentially or continuously performing a film forming step by a solvent cast method and a step of stretching the formed film, and the draw ratio is 1.2 to 1.8. It is preferable that it is double. In addition, the stretching may be performed in one stage or in multiple stages. When performing in multiple stages, the product of each draw ratio may be within this range.

  The stretching speed is preferably 5 to 1,000% / min, and more preferably 10 to 500% / min. The stretching temperature is preferably 30 to 160 ° C, more preferably 70 to 150 ° C, and particularly preferably 85 to 150 ° C. The stretching is preferably performed by a heat roll or / and a radiant heat source (such as an IR heater) or warm air. Moreover, you may provide a thermostat in order to improve the uniformity of temperature. When performing uniaxial stretching by roll stretching, it is preferable that L / W which is ratio of the distance (L) between rolls and the film width (W) of this phase difference plate is 2.0-5.0.

-Preheating process-
It is preferable to provide a preheating step before the stretching. You may heat-process after extending | stretching. The heat treatment temperature is preferably 20 ° C. to 10 ° C. higher than the glass transition temperature of the cellulose acylate film, and the heat treatment time is more preferably 1 second to 3 minutes. The heating method may be zone heating or partial heating using an infrared heater. You may slit the both ends of a film in the middle or the end of a process. These slit scraps are preferably recovered and reused as raw materials. Further, regarding the tenter, in JP-A-11-0777718, when the web is dried while the width is maintained by the tenter, the drying gas blowing method, blowing angle, wind speed distribution, wind speed, air volume, temperature difference, air volume difference, upper and lower blowing air volume By appropriately controlling the ratio and the use of a high specific heat drying gas, it is possible to ensure quality prevention such as flatness when increasing the speed by the solution casting method or widening the web width.

  Japanese Patent Laid-Open No. 11-077782 describes an invention in which a stretched thermoplastic resin film is heat treated by providing a temperature gradient in the width direction of the film in the thermal relaxation step after the stretching step in order to prevent unevenness. Yes.

  Furthermore, in order to prevent the occurrence of unevenness, Japanese Patent Application Laid-Open No. 4-204503 describes an invention in which the film is stretched with a solvent content of 2 to 10% based on the solid content.

  Further, in order to suppress curling due to the regulation of the clip biting width, Japanese Patent Application Laid-Open No. 2002-248680 discloses stretching with a tenter clip biting width D ≦ (33 / (log stretch rate × log volatile content)). Describes an invention that suppresses curling and facilitates film conveyance after the stretching step.

  Furthermore, in order to achieve both high-speed soft film conveyance and stretching, Japanese Patent Application Laid-Open No. 2002-337224 describes an invention in which tenter conveyance is switched between a first half pin and a second half clip.

  Japanese Patent Laid-Open No. 2002-187960 discloses that a cellulose ester dope solution is cast on a casting support for the purpose of easily improving the viewing angle characteristics and improving the viewing angle. The web (film) peeled from the support for stretching is stretched 1.0 to 4.0 times in at least one direction while the amount of residual solvent in the web is 100% by mass or less, particularly 10 to 100% by mass. An optically biaxial invention obtained by doing so is described. As a more preferred embodiment, it is described that the film is stretched 1.0 to 4.0 times in at least one direction while the amount of residual solvent in the web is in the range of 100% by mass or less, particularly 10 to 100% by mass. . In addition, as another stretching method, a circumferential speed difference is applied to a plurality of rolls, and a longitudinal stretching is performed using the difference between the circumferential speeds of the rolls, and both ends of the web are fixed with clips or pins. Examples include a method of extending the interval in the traveling direction and stretching in the vertical direction, a method of expanding in the horizontal direction and extending in the horizontal direction, a method of expanding the vertical and horizontal directions simultaneously and stretching in both the vertical and horizontal directions, a method using a combination of these, and the like. It has been. Furthermore, in the case of the so-called tenter method, it is shown that it is preferable to drive the clip portion by the linear drive method because smooth stretching can be performed and the risk of breakage and the like can be reduced.

  Furthermore, in order to produce a retardation film having little additive bleed-out, no delamination phenomenon between layers, good slipperiness and excellent transparency, it is described in JP-A-2003-014933. And a dope A containing a resin, an additive and an organic solvent, and a dope B containing no additive or an additive containing a resin, an additive and an organic solvent which are less than the dope A. The co-cast on the support so that the dope A is the core layer and the dope B is the surface layer, the organic solvent is evaporated until it can be peeled, and then the web is peeled off from the support and further stretched. The invention describes that the residual solvent in the resin film is stretched 1.1 to 1.3 times in at least one axial direction in the range of 3 to 50% by mass. Furthermore, as a preferred embodiment, the web is peeled from the support, and further, the dope containing a resin and an organic solvent is stretched 1.1 to 3.0 times in a uniaxial direction at a stretching temperature of 140 to 200 ° C. A dope B containing A, resin, fine particles and an organic solvent is prepared, and the dope A is co-cast on the support so that the dope A becomes a core layer and the dope B becomes a surface layer, and the organic solvent is made peelable. After evaporating the web, the web is peeled from the support and further stretched 1.1 to 3.0 times in the uniaxial direction in the range of 3 to 50% by mass of the residual solvent in the resin film during stretching. Further, the film is stretched 1.1 to 3.0 times in at least one axial direction at a stretching temperature in the range of 140 to 200 ° C., dope A containing a resin, an organic solvent and an additive, and no additive or additive. Resin, additive and presence of less than dope A A dope B containing a solvent, a dope C containing a resin, fine particles, and an organic solvent are prepared so that the dope A becomes a core layer, the dope B becomes a surface layer, and the dope C becomes a surface layer opposite to the dope B. The organic solvent is evaporated until it can be peeled off, the web is peeled off from the support, and the amount of residual solvent in the resin film during stretching is 3 to 50% by mass. Stretching at least uniaxially in a range of 1.1 to 3.0 times, stretching at a stretching temperature of 140 to 200 ° C. at least uniaxially in a direction of 1.1 to 3.0 times, The additive amount is 1-30% by mass with respect to the resin, the additive amount in the dope B is 0-5% by mass with respect to the resin, and the additive is a plasticizer, an ultraviolet absorber, or a retardation control agent. The organic solvent in dope A and dope B is methyl. It is preferred to use in that it contains more than 50 wt% of the total organic solvent chloride or methyl acetate.

  Furthermore, in Japanese Patent Application Laid-Open No. 2003-014933, as a stretching method, a web stretching machine called a tenter that stretches in the lateral direction by fixing the both ends of the web with clips and pins and widening the gap between the clips and pins in the lateral direction. It is described that can be preferably used. It is also disclosed that stretching or shrinking in the longitudinal direction can be performed by widening or shrinking the interval in the transport direction of the clip or pin in the transport direction (vertical direction) using a simultaneous biaxial stretching machine. . In addition, driving the clip portion by the linear drive method is preferable because it can be smoothly stretched and the risk of breakage can be reduced, and as a method of stretching in the longitudinal direction, a difference in peripheral speed is applied to a plurality of rolls. It is shown that a method of stretching in the longitudinal direction using a difference in peripheral speed between the rolls can be used. In addition, these extending | stretching methods can also be used combining, and extending | stretching processes may be divided into 2 steps or more like (longitudinal stretching, lateral stretching, longitudinal stretching) or (longitudinal stretching, longitudinal stretching). It is described that it is good.

  Furthermore, in order to prevent foaming of the tenter-dried web, improve detachability, and prevent dust generation, Japanese Patent Application Laid-Open No. 2003-004374 discloses that the hot air from the dryer is applied to both edges of the web. The invention is described in which the width of the dryer is formed shorter than the width of the web so as not to hit.

  Further, in order to prevent foaming of the tenter-dried web, improve releasability, and prevent dust generation, Japanese Patent Application Laid-Open No. 2003-019775 discloses that both ends of the web are prevented from hitting the holding portion of the tenter. An invention is described in which a wind shield is provided on the inside of the part.

  Furthermore, in order to stably carry and dry, JP 2003-053749 A discloses that the thickness after drying of both ends of the film supported by the pin tenter is X μm, and the average thickness after drying of the product part of the film. Is Tμm, when the relationship between X and T is Equation (1) T ≦ 60, 40 ≦ X ≦ 200, and Equation (2) when 60 <T ≦ 120, 40+ (T−60) × 0.2 The invention that satisfies the relationship of 52+ (T−120) × 0.2 ≦ X ≦ 400 when ≦ X ≦ 300 or Formula (3) 120 <T is described.

  In order to prevent wrinkles from occurring in the multistage tenter, JP-A-2-182654 discloses a tenter device in which a heating chamber and a cooling chamber are provided in a dryer of the multistage tenter, and left and right clip chains are provided. A separate cooling invention is described.

  Furthermore, in order to prevent web breakage, wrinkles, and conveyance failure, Japanese Patent Application Laid-Open No. 9-077315 describes an invention in which the inner pin density is increased and the outer pin density is decreased in the pin tenter pin. Yes.

  In addition, in order to prevent foaming of the web itself and adhesion of the web to the holding means in the tenter, Japanese Patent Application Laid-Open No. 9-085846 discloses that both side edge holding pins of the web are blown-type cooled in the tenter drying apparatus. An invention is described in which a pin is cooled to below the foaming temperature of the web and the pin immediately before the web is entrapped is cooled to a gelation temperature of the dope in the duct type cooler + 15 ° C. or lower.

  Further, in order to prevent pin tenter losing and improve foreign matter, Japanese Patent Application Laid-Open No. 2003-103542 discloses a web surface that cools the insertion structure and contacts the insertion structure in the pin tenter. An invention relating to a solution casting method in which the temperature does not exceed the gelling temperature of the web is described.

  In order to prevent deterioration in quality such as flatness when the speed is increased by the solution casting method or the width of the web is widened by a tenter, JP-A-11-0777718 discloses a web in the tenter. Is dried, the wind speed is 0.5-20 (40) m / s, the transverse temperature distribution is 10% or less, the web up-down air volume ratio is 0.2-1 and the dry gas ratio is 30-250 J /. The invention of Kmol is described. Furthermore, preferable drying conditions are disclosed depending on the amount of residual solvent in drying in the tenter. Specifically, after the web is peeled off from the support, the angle of the air blown from the air outlet is in the range of 30 to 150 ° with respect to the film plane until the amount of residual solvent in the web reaches 4% by mass. And when the wind speed distribution on the film surface located in the direction in which the drying gas is blown out is based on the upper limit value of the wind speed, the difference between the upper limit value and the lower limit value is within 20% of the upper limit value. When the blowout, drying the web, and the amount of residual solvent in the web is 130 to 70% by mass, the wind speed of the dry gas blown out from the blowout dryer is 0.5 to 20 m / sec. In addition, when the residual solvent amount is less than 70% by mass and 4% by mass or more, the dry gas is blown with a dry gas blown at a wind speed of 0.5 to 40 m / sec to dry the web in the width direction. Temperature When the cloth is based on the upper limit value of the gas temperature, the difference between the upper limit value and the lower limit value is within 10% of the upper limit value, and the amount of residual solvent in the web is 4 to 200% by mass. It is described that the air volume ratio q of the dry gas blown out from the blow-out port of the blow-type dryer located above and below the web satisfies 0.2 ≦ q ≦ 1. Further, as a preferred embodiment, at least one kind of gas is used for the drying gas, the average specific heat is 31.0 to 250 J / K · mol, and the organic compound that is liquid at room temperature contained in the drying gas during drying is used. It is disclosed that the concentration is dried with a drying gas having a saturated vapor pressure of 50% or less.

  Further, in order to prevent the flatness and coating from deteriorating due to the generation of contaminants, Japanese Patent Application Laid-Open No. 11-0777719 discloses an invention in which a tenter clip incorporates a heating portion in a TAC manufacturing apparatus. Are listed. As a more preferable aspect, a device for removing foreign matter generated at the contact portion between the clip and the web between the time when the tenter clip releases the web and the time when the web is carried again, a jetting gas or liquid, and Remove the foreign matter using a brush, the residual amount when the clip or pin contacts the web is 12 to 50% by mass, the surface temperature of the contact portion between the clip or pin and the web is 60 ° to 200 ° (More preferably, 80 to 120 °) and the like are disclosed.

  In order to improve flatness, improve quality deterioration due to tearing in the tenter, and increase productivity, Japanese Patent Application Laid-Open No. 11-090943 discloses an arbitrary transport length Lt (m) of the tenter. The ratio Lr = Ltt / Lt of the total length Ltt (m) in the conveying direction of the portion where the clip of the tenter having the same length as Lt holds the web is 1.0 ≦ Lr ≦ 1.99 The invention is described. Furthermore, as a preferable aspect, it is disclosed that the portion for holding the web is arranged without a gap when viewed from the web width direction.

  In addition, when introducing a web into a tenter, in order to improve flatness deterioration and instability due to web sagging, Japanese Patent Application Laid-Open No. 11-090944 discloses a plastic film manufacturing apparatus in front of a tenter entrance. Describes an invention having a sag suppressing device in the web width direction. Further, as a more preferable aspect, the sag suppressing device is a rotating roller that rotates in the direction range of 2 to 60 ° in the width direction, has an air intake device on the top of the web, and can blow air from under the web. Having a blower is also disclosed.

  In order to prevent deterioration of quality and sagging that hinders productivity, Japanese Patent Application Laid-Open No. 11-090945 discloses that a web peeled from a support has an angle with respect to the horizontal in the TAC manufacturing method. The invention to be introduced into the tenter is described.

  In order to make a film having stable physical properties, Japanese Patent Application Laid-Open No. 2000-289903 discloses a transport device that transports while applying tension in the width direction of the web when the peeled and solvent content is 50 to 12% by mass. A web width detecting means, a web holding means, and an invention that has two or more variable bending points, calculates the web width from a detection signal in web width detection, and changes the position of the bending point. Has been.

  Furthermore, in order to improve the clipping property, prevent web breakage for a long period of time, and obtain a film with excellent quality, Japanese Patent Application Laid-Open No. 2003-033933 discloses the right and left sides of the web on the left and right sides near the entrance of the tenter. A web side edge curl prevention guide plate is disposed at least below the upper and lower side edges, and the web facing surface of the guide plate is arranged in the web conveying direction and the web. It is described that it comprises a contact metal part. As a more preferred embodiment, the web contact resin portion of the web facing surface of the guide plate is disposed on the upstream side in the web conveyance direction, and the web contact metal portion is disposed on the downstream side, the web contact resin portion of the guide plate and The level difference (including the inclination) between the web contact metal parts is within 500 μm, and the width of the guide plate web contact resin part and the web contact metal part contacting the web is 2 respectively. The distance between the web contact resin part of the guide plate and the web contact metal part of the web contact direction in contact with the web is 5 to 120 mm, respectively, and the web contact resin part of the guide plate is metal. The guide board is made by surface resin processing or resin coating, the web contact resin part of the guide plate is made of a single resin, the left and right side edges of the web The distance between the web facing surfaces of the guide plates arranged above and below is 3 to 30 mm, and the distance between the web facing surfaces of the upper and lower guide plates at the left and right side edges of the web. In the width direction of the web and inward, it is enlarged at a rate of 2 mm or more per 100 mm width, and the upper and lower guide plates have a length of 10 to 300 mm at the left and right side edges of the web, respectively. And the upper and lower guide plates are arranged so as to be displaced back and forth along the web conveying direction, and the distance of the deviation between the upper and lower guide plates is −200 to +200 mm, the upper guide The web facing surface of the plate is made of resin or metal only, the web contact resin portion of the guide plate is made of Teflon (registered trademark), and the web contact metal portion is made of stainless steel. It is disclosed that it is made of stainless steel, the surface roughness of at least one of the web facing surface of the guide plate or the web contact resin portion and the web contact metal portion provided on the guide plate is 3 μm or less. Has been. Further, it is also described that the installation position of the upper and lower guide plates for preventing web side edge curl generation is preferably between the peeling side end portion of the support and the tenter introduction portion, and more preferably installed near the tenter entrance. Has been.

  Further, in order to prevent the cutting and unevenness of the web that occurs during drying in the tenter, Japanese Patent Application Laid-Open No. 11-048271 discloses a width stretching device at the time when the solvent content of the web is 50 to 12% by mass after peeling. The invention is described in which the film is stretched and dried at the time when the web has a solvent content of 10% by mass or less, and a pressure device applies a pressure of 0.2 to 10 KPa from both sides of the web. As a more preferred embodiment, when applying pressure using a nip roll as a method of finishing applying tension when the solvent content is 4% by mass or more or applying pressure from both sides of the web (film), the number of nip roll pairs is from 1. It is also disclosed that about 8 sets are preferable, and the temperature when pressurizing is preferably 100 to 200 ° C.

In addition, JP 2002-036266, which is an invention for obtaining a high-quality thin tack having a thickness of 20 to 85 μm, has, as a preferred mode, a tension that acts on the web along the conveying direction before and after the tenter. The difference is 8 N / mm ² or less, a preheating step for preheating the web after the peeling step, a stretching step for stretching the web using a tenter after the preheating step, and a web after the stretching step. And a relaxation step for relaxing the film by a smaller amount than the stretching amount in the stretching step, and the temperature T1 in the preheating step and the stretching step is set to (glass transition temperature Tg-60) ° C. or more and relaxation. The temperature T2 in the process is set to (T1-10) ° C. or less, and the web stretch ratio in the stretching process is 0 to 3 in a ratio to the web width immediately before entering the stretching process. % In the web stretch ratio in the relaxation step, to -10 to 10%, etc. is disclosed.

  Further, JP 2002-225054 A, which aims to have a dry film thickness of 10 to 60 μm and a low durability that is lightweight and moisture-permeable, has a residual solvent amount of 10 mass after peeling. %, The both ends of the web are gripped with clips, and drying shrinkage suppression by holding the width and at least one of stretching in the width direction are performed, and expressed by the formula S = {(Nx + Ny) / 2} −Nz. Forming a film having a degree of plane orientation (S) of 0.0008 to 0.0020 (where Nx is the refractive index in the direction of the largest refractive index in the plane of the film, and Ny is a surface with respect to Nx) The refractive index in a direction perpendicular to the inside, Nz is the refractive index in the film thickness direction), the time from casting to peeling is set to 30 to 90 seconds, and the web after peeling is at least in the width direction and the longitudinal direction. Stretching to either, etc. disclosed It has been.

  Japanese Patent Application Laid-Open No. 2002-341144 describes a solution casting method having a stretching process in which the mass concentration of a retardation increasing agent has a higher optical distribution as it approaches the center in the film width direction in order to suppress optical unevenness. Has been.

  Furthermore, in Japanese Patent Application Laid-Open No. 2003-071863, which is an invention for obtaining a film that does not cause fogging, the stretching ratio in the width direction is preferably 0 to 100%, and when used as a polarizing plate protective film, It is described that 5 to 20% is more preferable, and 8 to 15% is particularly preferable. On the other hand, when used as a retardation film, 10 to 40% is more preferable, and 20 to 30% is more preferable. Ro can be controlled by a stretching ratio, and a film having a higher stretching ratio is completed. It is disclosed that it is preferable because of its excellent flatness. Further, when the tenter is used, the residual solvent amount of the film is preferably 20 to 100% by mass at the start of the tenter, and drying is performed while the tenter is applied until the residual solvent amount of the film becomes 10% by mass or less. It is shown that 5 mass% or less is more preferable. Moreover, 30-150 degreeC is preferable, as for the drying temperature in the case of performing a tenter, 50-120 degreeC is more preferable, and 70-100 degreeC is especially preferable. It is also disclosed that the lower the drying temperature, the less the transpiration of the UV absorber, the plasticizer, etc., and the process contamination can be reduced, while the higher the drying temperature, the better the flatness of the film.

  Japanese Patent Application Laid-Open No. 2002-248639, which is an invention that reduces vertical and horizontal dimension fluctuations during storage under high temperature and high humidity conditions, continuously casts a cellulose ester solution on a support. In the method of producing a film to be peeled and dried, the invention is described in which the drying shrinkage satisfies the formula: 0 ≦ dry shrinkage (%) ≦ 0.1 × residual solvent amount (%) when peeling. Has been. Furthermore, as a preferred embodiment, when the residual solvent amount of the cellulose ester film after peeling is in the range of 40 to 100% by mass, the residual solvent amount is at least 30% by mass while holding both ends of the cellulose ester film by tenter conveyance. The amount of residual solvent at the tenter conveyance entrance of the cellulose ester film after peeling is 40 to 100% by mass, the amount of residual solvent at the exit is 4 to 20% by mass, and the cellulose ester film is removed by tenter conveyance. It is disclosed that the tension to be conveyed increases from the entrance to the exit of the tenter conveyance, the tension to convey the cellulose ester film by the tenter conveyance and the tension in the width direction of the cellulose ester film are substantially equal. Yes.

  In order to obtain a film having a thin film thickness and excellent optical isotropy and flatness, Japanese Patent Application Laid-Open No. 2000-239403 discloses a residual solvent ratio X at the time of peeling and a residual solvent at the time of introduction into a tenter. It is disclosed that film formation is performed with the relationship of the rate Y being in the range of 0.3X ≦ Y ≦ 0.9X.

  Japanese Patent Application Laid-Open No. 2002-286933 includes a method of stretching a film to be formed by casting, a method of stretching under heating conditions and a method of stretching under solvent-containing conditions, and stretching under heating conditions. In some cases, it is preferable to stretch at a temperature below the glass transition point of the resin. On the other hand, when the cast film is stretched under solvent-impregnated conditions, the once dried film is contacted with the solvent again. It is disclosed that it can be impregnated with a solvent and stretched.

-Retardation raising agent-
By adding the retardation increasing agent to a material such as a film, the retardation value at each wavelength can be adjusted.
In the present specification, “retardation increasing agent” means a cellulose acylate film produced in exactly the same manner except that the Re retardation value measured at a wavelength of 550 nm of a cellulose acylate film containing an additive does not contain the additive. It means an “additive” that is 20 nm or more higher than the Re retardation value (unstretched state) measured at a wavelength of 550 nm. The increase in the retardation value is preferably 30 nm or more, more preferably 40 nm or more, and particularly preferably 60 nm or more.

The retardation increasing agent is preferably a compound having at least two aromatic rings. The retardation increasing agent is preferably used in the range of 0.01 to 20 parts by mass, more preferably in the range of 0.1 to 10 parts by mass, with respect to 100 parts by mass of the polymer. More preferably, it is used in the range of ˜5 parts by mass, and most preferably in the range of 0.5-2 parts by mass. Two or more types of retardation increasing agents may be used in combination.
The retardation increasing agent preferably has maximum absorption in a wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

In the present specification, the “aromatic ring” includes an aromatic hetero ring in addition to an aromatic hydrocarbon ring.
The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).
The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.
As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable. In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.

The number of aromatic rings contained in the retardation increasing agent is preferably 2 to 20, more preferably 2 to 12, still more preferably 2 to 8, and particularly preferably 2 to 6. preferable.
The bonding relationship between two aromatic rings can be classified into (a) when forming a condensed ring, (b) when directly connecting with a single bond, and (c) when connecting via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

  Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiantole Ring is included. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.

  The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded by two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.

The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-

The aromatic ring and the linking group may have a substituent.
Examples of the substituent include halogen atom (F, Cl, Br, I), hydroxyl, carboxyl, cyano, amino, nitro, sulfo, carbamoyl, sulfamoyl, ureido, alkyl group, alkenyl group, alkynyl group, aliphatic acyl Group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group, aliphatic substituted carbamoyl group, fatty acid An aromatic substituted sulfamoyl group, an aliphatic substituted ureido group and a non-aromatic heterocyclic group are included.

The alkyl group preferably has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is more preferable. The alkyl group may further have a substituent (eg, hydroxy, carboxy, alkoxy group, alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl and 2-diethylaminoethyl.
The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is more preferable. The alkenyl group may further have a substituent. Examples of alkenyl groups include vinyl, allyl and 1-hexenyl.
The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is more preferable. The alkynyl group may further have a substituent. Examples of alkynyl groups include ethynyl, 1-butynyl and 1-hexynyl.

The aliphatic acyl group preferably has 1 to 10 carbon atoms. Examples of the aliphatic acyl group include acetyl, propanoyl and butanoyl.
The aliphatic acyloxy group preferably has 1 to 10 carbon atoms. Examples of the aliphatic acyloxy group include acetoxy.
The alkoxy group preferably has 1 to 8 carbon atoms. The alkoxy group may further have a substituent (eg, an alkoxy group). Examples of alkoxy groups (including substituted alkoxy groups) include methoxy, ethoxy, butoxy and methoxyethoxy.
The alkoxycarbonyl group preferably has 2 to 10 carbon atoms. Examples of the alkoxycarbonyl group include methoxycarbonyl and ethoxycarbonyl.
The alkoxycarbonylamino group preferably has 2 to 10 carbon atoms. Examples of the alkoxycarbonylamino group include methoxycarbonylamino and ethoxycarbonylamino.

The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include methylthio, ethylthio and octylthio.
The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include methanesulfonyl and ethanesulfonyl.
The aliphatic amide group preferably has 1 to 10 carbon atoms. Examples of the aliphatic amide group include acetamide.
The aliphatic sulfonamide group preferably has 1 to 8 carbon atoms. Examples of the aliphatic sulfonamido group include methanesulfonamido, butanesulfonamido and n-octanesulfonamido.
The aliphatic substituted amino group preferably has 1 to 10 carbon atoms. Examples of the aliphatic substituted amino group include dimethylamino, diethylamino and 2-carboxyethylamino.
The aliphatic substituted carbamoyl group preferably has 2 to 10 carbon atoms. Examples of the aliphatic substituted carbamoyl group include methylcarbamoyl and diethylcarbamoyl.
The aliphatic substituted sulfamoyl group preferably has 1 to 8 carbon atoms. Examples of the aliphatic substituted sulfamoyl group include methylsulfamoyl and diethylsulfamoyl.
The aliphatic substituted ureido group preferably has 2 to 10 carbon atoms. Examples of the aliphatic substituted ureido group include methylureido.
Examples of the non-aromatic heterocyclic group include piperidino and morpholino.
The molecular weight of the retardation increasing agent is preferably 300 to 800.

  As the retardation increasing agent, a rod-shaped compound having a linear molecular structure can be preferably used in addition to a compound using a 1,3,5-triazine ring. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation can be performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited) to determine the molecular structure that minimizes the heat of formation of the compound. The molecular structure being linear means that in the thermodynamically most stable structure obtained by calculation as described above, the angle of the main chain constituting the molecular structure is 140 degrees or more.

As the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (1) is preferable.
Formula (1): Ar ¹ -L ¹ -Ar ²
However, in the said General formula (1), Ar < ¹ > and Ar < ² > are aromatic groups each independently.

In the present invention, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group.
The aryl group and the substituted aryl group are more preferable than the aromatic heterocyclic group and the substituted aromatic heterocyclic group. The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable. As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is more preferable. .

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom (F, Cl, Br, I), hydroxyl, carboxyl, cyano, amino, alkylamino group (eg, methylamino, ethyl). Amino, butylamino, dimethylamino), nitro, sulfo, carbamoyl, alkylcarbamoyl groups (eg, N-methylcarbamoyl, N-ethylcarbamoyl, N, N-dimethylcarbamoyl), sulfamoyl, alkylsulfamoyl groups (eg, N -Methylsulfamoyl, N-ethylsulfamoyl, N, N-dimethylsulfamoyl), ureido, alkylureido groups (eg, N-methylureido, N, N-dimethylureido, N, N, N-trimethyl) Ureido), alkyl groups (eg, methyl, ethyl, propyl, butyl, pentyl) Heptyl, octyl, isopropyl, s-butyl, t-amyl, cyclohexyl, cyclopentyl), alkenyl groups (eg, vinyl, allyl, hexenyl), alkynyl groups (eg, ethynyl, butynyl), acyl groups (eg, formyl, acetyl, Butyryl, hexanoyl, lauryl), acyloxy groups (eg, acetoxy, butyryloxy, hexanoyloxy, lauryloxy), alkoxy groups (eg, methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy), aryloxy groups (Eg, phenoxy), alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, heptyloxycarbonyl), aryloxycar Nyl group (eg, phenoxycarbonyl), alkoxycarbonylamino group (eg, butoxycarbonylamino, hexyloxycarbonylamino), alkylthio group (eg, methylthio, ethylthio, propylthio, butylthio, pentylthio, heptylthio, octylthio), arylthio group (eg, , Phenylthio), alkylsulfonyl groups (eg, methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, pentylsulfonyl, heptylsulfonyl, octylsulfonyl), amide groups (eg, acetamide, butylamide group, hexylamide, laurylamide) and non- Aromatic heterocyclic groups (eg, morpholyl, pyrazinyl) are included.

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom, cyano, carboxyl, hydroxyl, amino, alkyl-substituted amino group, acyl group, acyloxy group, amide group, alkoxycarbonyl group, alkoxy group, Alkylthio groups and alkyl groups are preferred. The alkyl part and alkyl group of the alkylamino group, alkoxycarbonyl group, alkoxy group and alkylthio group may further have a substituent. Examples of alkyl moieties and substituents of alkyl groups include halogen atoms, hydroxyl, carboxyl, cyano, amino, alkylamino groups, nitro, sulfo, carbamoyl, alkylcarbamoyl groups, sulfamoyl, alkylsulfamoyl groups, ureido, alkylureido Group, alkenyl group, alkynyl group, acyl group, acyloxy group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, alkylsulfonyl group, amide group and non-aromatic An aromatic heterocyclic group is included. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, hydroxyl, amino, alkylamino group, acyl group, acyloxy group, acylamino group, alkoxycarbonyl group and alkoxy group are preferable.

In the general formula (1), L ¹ is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a combination thereof.
The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is more preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group.
The number of carbon atoms in the alkylene group is preferably 1-20, more preferably 1-15, particularly preferably 1-10, still more preferably 1-8, and most preferably 1-6.

The alkenylene group and alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure.
The alkenylene group and the alkynylene group have 2 to 10 carbon atoms, preferably 2 to 8, more preferably 2 to 6, particularly preferably 2 to 4, and most preferably 2 (vinylene or ethynylene).
The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and particularly preferably 6 to 12.

In the molecular structure of the general formula (1), it is preferable that an angle formed by Ar ¹ and Ar ² with respect to L ¹ is 140 degrees or more.
As the rod-like compound, a compound represented by the following formula (2) is more preferable.
Formula ^{(2): Ar 1 -L 2} -X-L 3 -Ar 2
In the general formula (2), Ar ¹ and Ar ² are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Ar ¹ and Ar ^{2 in} the general formula (1).

In the general formula (2), L ² and L ³ are each independently a divalent linking group selected from an alkylene group, —O—, —CO—, and a group consisting of a combination thereof.
The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure.
The number of carbon atoms of the alkylene group is preferably 1 to 10, more preferably 1 to 8, particularly preferably 1 to 6, still more preferably 1 to 4, and 1 or 2 (methylene or ethylene). Is most preferred.
L ² and L ³ are particularly preferably —O—CO— or CO—O—.

In the general formula (2), X is 1,4-cyclohexylene, vinylene or ethynylene.
Specific examples of the compound represented by the general formula (2) are shown below.

  Specific examples (1) to (34), (41), and (42) have two asymmetric carbon atoms at the 1-position and the 4-position of the cyclohexane ring. However, since the specific examples (1), (4) to (34), (41), and (42) have a symmetrical meso type molecular structure, there are no optical isomers (optical activity), and geometric isomers (trans Type and cis type). The trans type (1-trans) and cis type (1-cis) of specific example (1) are shown below.

As described above, the rod-like compound preferably has a linear molecular structure. Therefore, the trans type is preferable to the cis type.
Specific examples (2) and (3) have optical isomers (a total of four isomers) in addition to geometric isomers. As for geometric isomers, the trans type is similarly preferable to the cis type. The optical isomer is not particularly superior or inferior, and may be D, L or a racemate.
In specific examples (43) to (45), the central vinylene bond includes a trans type and a cis type. For the same reason as described above, the trans type is preferable to the cis type.
Other preferred compounds are shown below.

The rod-like compound can be synthesized with reference to methods described in literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989); Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. 40, 420 (1975), Tetrahedron, 48, 16, 3437 (1992).
The retardation increasing agent may be used in combination of two or more rod-like compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution.
The addition amount of the retardation increasing agent is preferably 0.1 to 30% by mass and more preferably 0.5 to 20% by mass based on the amount of the polymer.

  The said aromatic compound is used in 0.01-20 mass parts with respect to 100 mass parts of cellulose acylates. The aromatic compound is preferably used in the range of 0.05 to 15 parts by mass and more preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the cellulose acylate. Two or more kinds of compounds may be used in combination.

  The cellulose acylate film is preferably subjected to a surface treatment. The surface treatment includes corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, alkali saponification treatment and ultraviolet irradiation treatment. The surface treatment is described on pages 30 to 32 of the Japan Society for Invention and Innovation Technical Bulletin No. 2001-1745.

  The alkali saponification treatment is carried out by immersing the cellulose acylate film in a saponification solution or applying the saponification solution to the cellulose acylate film. A method by coating is preferred. Application methods include dip coating, curtain coating, extrusion coating, bar coating, and E-type application. The alkali is preferably a hydroxide of an alkali metal (eg, potassium or sodium). That is, the alkali treatment liquid is preferably an alkali metal hydroxide solution. It is preferable that the density | concentration of the hydroxide ion in a solution is 0.1-3.0 mol / L. A solvent, a surfactant, and a wetting agent (eg, diol, glycerin) having good wettability with respect to the film are added to the alkali treatment liquid, and the wettability of the alkali treatment liquid with respect to the second optical anisotropic layer and the treatment liquid Stability can be improved. The solvent having good wettability with respect to the film is preferably alcohol (eg, isopropyl alcohol, n-butanol, methanol, ethanol). Additives for the alkali treatment liquid are described in JP-A No. 2002-82226 and WO 02/46809 pamphlet.

  An undercoat layer (described in JP-A-7-333433) may be provided instead of or in addition to the surface treatment. A plurality of undercoat layers may be provided. For example, a polymer layer containing both a hydrophobic group and a hydrophilic group is provided as a first undercoat layer, and a hydrophilic polymer layer that adheres well to the alignment film is provided thereon as a second undercoat layer (Japanese Patent Laid-Open No. Hei. 11-248940).

-Alignment film-
The alignment film is an organic compound (eg, ω-tricosane) formed by rubbing treatment of an organic compound (preferably a polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). Acid, dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.

  The alignment film is preferably formed by a rubbing treatment of a polymer. In principle, the polymer used for the alignment film has a molecular structure having a function of aligning liquid crystal molecules. The polymer used for the alignment film preferably has a function of fixing the alignment of the liquid crystalline molecules in addition to the function of aligning the liquid crystalline molecules. For example, a side chain having a crosslinkable functional group (eg, a double bond) is bonded to the main chain of the polymer, or a crosslinkable functional group having a function of orienting liquid crystal molecules is introduced into the polymer side chain. It is preferable. The polymer used for the alignment film is preferably crosslinkable per se or can be crosslinked by the use of a crosslinking agent. Crosslinkable polymers are described in paragraph [0022] of JP-A-8-338913. Examples of crosslinkable polymers include polymethacrylate, polystyrene, polyolefin, polyvinyl alcohol, modified polyvinyl alcohol, poly (N-methylolacrylamide), polyester, polyimide, polyvinyl acetate, carboxymethylcellulose, polycarbonate, and copolymers thereof. included. Silane coupling agents can also be used as the polymer. Water-soluble polymers (eg, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, modified polyvinyl alcohol) are preferred, gelatin, polyvinyl alcohol and modified polyvinyl alcohol are more preferred, and polyvinyl alcohol and modified polyvinyl alcohol are particularly preferred. . It is particularly preferable to use two or more types of polyvinyl alcohol or modified polyvinyl alcohol having different degrees of polymerization.

  The saponification degree of the polyvinyl alcohol is preferably 70 to 100%, more preferably 80 to 100%. The polymerization degree of polyvinyl alcohol is preferably 100 to 5,000. A side chain having a function of aligning liquid crystal molecules generally has a hydrophobic group as a functional group. The specific type of functional group is determined according to the type of liquid crystal molecule and the required alignment state. The modifying group of the modified polyvinyl alcohol can be introduced by copolymerization modification, chain transfer modification or block polymerization modification. Examples of modifying groups are hydrophilic groups (eg, carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, amino, ammonio, amide, thiol), hydrocarbon groups having 10 to 100 carbon atoms, and fluorine atom-substituted hydrocarbons. Groups, alkylthio groups, polymerizable groups (eg, unsaturated polymerizable groups, epoxy groups, azirinidyl groups), and alkoxysilyl groups (trialkoxysilyl, dialkoxysilyl, monoalkoxysilyl). Modified polyvinyl alcohol is described in JP-A Nos. 2000-155216 and 2002-62426.

  When the side chain having the crosslinkable functional group is bonded to the main chain of the alignment film polymer or the crosslinkable functional group is introduced into the side chain having the function of aligning the liquid crystalline molecules, A polyfunctional monomer contained in the optically anisotropic layer can be copolymerized. As a result, not only between the polyfunctional monomer and the polyfunctional monomer, but also between the alignment film polymer and the alignment film polymer and between the polyfunctional monomer and the alignment film polymer is firmly bonded by a covalent bond. Therefore, the strength of the optical compensation film can be remarkably improved by introducing the crosslinkable functional group into the alignment film polymer. The crosslinkable functional group of the alignment film polymer is described in paragraphs [0080] to [0100] of JP-A No. 2000-155216.

  Apart from the crosslinkable functional group, the alignment film polymer can also be crosslinked using a crosslinking agent. Crosslinking agents include aldehydes, N-methylol compounds, dioxane derivatives, compounds that act by activating carboxyl groups, active vinyl compounds, active halogen compounds, isoxazole and dialdehyde starch. Two or more kinds of crosslinking agents may be used in combination. The crosslinking agent is described in JP-A No. 2002-62426. Aldehydes having high reaction activity, particularly glutaraldehyde are preferred. 0.1-20 mass% is preferable with respect to a polymer, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable. The amount of the unreacted crosslinking agent remaining in the alignment film is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less. By reducing the residual amount of the cross-linking agent, sufficient durability without reticulation can be obtained even when the liquid crystal display device is used for a long time or when the liquid crystal display device is left in a high-temperature and high-humidity atmosphere for a long time. can get.

  The alignment film can be formed by applying a coating liquid containing the polymer and a crosslinking agent onto the second optically anisotropic layer, followed by drying by heating (crosslinking) and rubbing treatment. The crosslinking reaction is performed after coating on the second optically anisotropic layer. When a water-soluble polymer such as polyvinyl alcohol is used as the alignment film forming material, the coating solution is preferably a mixed solvent of an organic solvent (eg, methanol) having a defoaming action and water. In the case of a mixed solvent of water and methanol, methanol is preferably contained in an amount of 1% by mass or more, more preferably 9% by mass or more based on the entire solvent. By adding the organic solvent, generation of bubbles is suppressed, and defects on the surfaces of the alignment film and the first optical anisotropic layer are remarkably reduced.

  The alignment film is preferably applied by spin coating, dip coating, curtain coating, extrusion coating, rod coating or roll coating. A rod coating method is particularly preferable. The film thickness after drying is preferably 0.1 to 10 μm. Heat drying can be performed at 20-110 degreeC. In order to form sufficient crosslinking, 60 to 100 ° C is preferable, and 80 to 100 ° C is more preferable. The drying time can be 1 minute to 36 hours, preferably 1 to 30 minutes. The pH is preferably set to an optimum value for the crosslinking agent to be used. When glutaraldehyde is used, the pH is preferably 4.5 to 5.5.

The alignment film can be obtained by rubbing the surface. The rubbing treatment is the same as the treatment method widely adopted as the liquid crystal alignment treatment process of LCD. That is, the orientation is obtained by rubbing the surface of the orientation film in a certain direction using paper, gauze, felt, rubber, nylon, or polyester fiber. In general, rubbing is performed several times using a cloth in which fibers having a uniform length and thickness are flocked on average.

(Polarizer)
The polarizing plate of the present invention comprises a laminate in which the second optical anisotropic layer of the present invention and the first optical anisotropic layer of the present invention are bonded to at least one side of the polarizing film, and at least the optical film of the present invention. The compensation film has optical properties.

-Polarizing film-
The polarizing film includes an orientation type polarizing film or a coating type polarizing film (manufactured by Optiva Inc.). The oriented polarizing film is composed of a binder and iodine or a dichroic dye. Iodine and dichroic dyes exhibit polarization performance by being oriented in the binder. It is preferable that the iodine and the dichroic dye are aligned along the binder molecule, or the dichroic dye is aligned in one direction by self-assembly such as liquid crystal. A commercially available oriented polarizing film is produced by immersing a stretched polymer in a solution of iodine or dichroic dye in a bath and allowing the iodine or dichroic dye to penetrate into the binder. . In addition, commercially available polarizing films have iodine or dichroic dye distributed about 4 μm from the polymer surface (about 8 μm on both sides), and a thickness of at least 10 μm is necessary to obtain sufficient polarization performance. is there. The degree of penetration can be controlled by the solution concentration of iodine or dichroic dye, the bath temperature and the immersion time. The thickness of the polarizing film is preferably not more than a commercially available polarizing plate (about 30 μm), more preferably 25 μm or less, and particularly preferably 20 μm or less. When the thickness is 20 μm or less, the light leakage phenomenon is not observed in the 17-inch liquid crystal display device.

  The binder of the polarizing film may be cross-linked. As the binder for the polarizing film, a polymer that can be crosslinked by itself may be used. Applying light, heat, or pH change to a polymer having a functional group, or a polymer obtained by introducing a functional group into the polymer, reacting the functional group to crosslink between the polymers to form a polarizing film it can. Moreover, you may introduce | transduce a crosslinked structure into a polymer with a crosslinking agent. It can be formed by cross-linking between binders by introducing a bonding group derived from the cross-linking agent between binders using a cross-linking agent which is a compound having high reaction activity. In general, crosslinking can be performed by applying a coating solution containing a crosslinkable polymer or a mixture of a polymer and a crosslinking agent on a transparent support and then heating. Since it is only necessary to ensure durability at the stage of the final product, the cross-linking treatment may be performed at any stage until the final polarizing plate is obtained.

  As the binder of the polarizing film, a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used. Examples of polymers include polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, polystyrene, polyvinyl alcohol, modified polyvinyl alcohol, poly (N-methylol acrylamide), polyvinyl toluene, chlorosulfonated polyethylene, nitrocellulose, chlorinated polyolefin ( Eg, polyvinyl chloride), polyester, polyimide, polyvinyl acetate, polyethylene, carboxymethylcellulose, polypropylene, polycarbonate and copolymers thereof (eg, acrylic acid / methacrylic acid copolymer, styrene / maleimide copolymer, styrene / vinyl) Toluene copolymer, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer). A silane coupling agent may be used as the polymer. Water-soluble polymers (eg, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol and modified polyvinyl alcohol) are preferred, gelatin, polyvinyl alcohol and modified polyvinyl alcohol are more preferred, and polyvinyl alcohol and modified polyvinyl alcohol are particularly preferred. .

The saponification degree of the polyvinyl alcohol and the modified polyvinyl alcohol is preferably 70 to 100%, more preferably 80 to 100%, and particularly preferably 95 to 100%. The polymerization degree of polyvinyl alcohol is preferably 100 to 5,000. Modified polyvinyl alcohol is obtained by introducing a modifying group into polyvinyl alcohol by copolymerization modification, chain transfer modification or block polymerization modification. Examples of the modifying group to be introduced in _{copolymerization, -COONa, -Si (OX) 3} (X is a hydrogen atom or an alkyl _{group), - N (CH3) 3} · Cl, -C 9 H 19, -COO, - SO _{3 Na,} including _-C 12 _{H 25.} Examples of the modifying group to be introduced in the chain transfer include -COONa, _-SH, a _-SC 12 _{H 25.} The degree of polymerization of the modified polyvinyl alcohol is preferably 100 to 3,000. The modified polyvinyl alcohol is described in JP-A-8-338913, JP-A-9-152509, and JP-A-9-316127. Unmodified polyvinyl alcohol and alkylthio-modified polyvinyl alcohol having a saponification degree of 85 to 95% are particularly preferable. Two or more kinds of polyvinyl alcohol and modified polyvinyl alcohol may be used in combination.

  The crosslinking agent is described in U.S. Reissue Pat. No. 23297. Boron compounds (eg, boric acid, borax) can also be used as a crosslinking agent. When a large amount of the crosslinking agent for the binder is added, the heat and humidity resistance of the polarizing film can be improved. However, when 50 mass% or more of a crosslinking agent is added to the binder, the orientation of iodine or the dichroic dye is lowered. 0.1-20 mass% is preferable with respect to a binder, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable. The binder contains some crosslinking agent that has not reacted even after the crosslinking reaction has been completed. However, the amount of the remaining crosslinking agent is preferably 1.0% by mass or less in the binder, and more preferably 0.5% by mass or less. When the crosslinking agent is contained in the binder in an amount exceeding 1.0% by mass, there may be a problem in durability. That is, when a polarizing film having a large amount of residual crosslinking agent is incorporated in a liquid crystal display device and used for a long time or left in a high-temperature and high-humidity atmosphere for a long time, the degree of polarization may decrease.

  The dichroic dye includes an azo dye, a stilbene dye, a pyrazolone dye, a triphenylmethane dye, a quinoline dye, an oxazine dye, a thiazine dye, or an anthraquinone dye. The dichroic dye is preferably water-soluble. The dichroic dye preferably has a hydrophilic substituent (eg, sulfo, amino, hydroxyl). Examples of dichroic dyes include C.I. I. Direct Yellow 12, C.I. I. Direct Orange 39, C.I. I. Direct Orange 72, C.I. I. Direct Red 39, C.I. I. Direct Red 79, C.I. I. Direct Red 81, C.I. I. Direct Red 83, C.I. I. Direct Red 89, C.I. I. Direct Violet 48, C.I. I. Direct Blue 67, C.I. I. Direct Blue 90, C.I. I. Direct Green 59, C.I. I. Acid Red 37 is included. Regarding the dichroic dye, JP-A-1-161202, JP-A-1-172906, JP-A-1-172907, JP-A-1-183602, JP-A-1-248105, JP-A-1-265205, There is description in each gazette of 7-261024.

  The dichroic dye is used as a free acid or salt (eg, alkali metal salt, ammonium salt or amine salt). By blending two or more kinds of dichroic dyes, polarizing films having various hues can be produced. A polarizing film using a compound (pigment) that exhibits a black color when the polarization axes are orthogonal to each other, or a polarizing film that is blended with various dichroic molecules to exhibit a black color, has excellent single-plate transmittance and polarization rate. .

  The polarizing film extends the binder in the longitudinal direction (MD direction) of the polarizing film (stretching method). Alternatively, after rubbing, staining with iodine or a dichroic dye (rubbing method). In the stretching method, the stretching ratio is preferably 2.5 to 30.0 times, and more preferably 3.0 to 10.0 times. Stretching can be performed by dry stretching in air. Moreover, you may implement wet extending | stretching in the state immersed in water. The stretch ratio of dry stretching is preferably 2.5 to 5.0 times, and the stretch ratio of wet stretching is more preferably 3.0 to 10.0 times. The stretching step may be performed in several steps. By dividing into several times, it is possible to stretch more uniformly even at high magnification. Before stretching, a slight stretching may be performed horizontally or vertically (a degree that prevents shrinkage in the width direction).

The polarizing film is preferably stretched at an angle of 10 to 80 ° with respect to the longitudinal direction from the viewpoint of yield. In that case, stretching can be carried out by performing tenter stretching in biaxial stretching in different steps. The biaxial stretching is the same as the stretching method performed in normal film formation. In biaxial stretching, stretching is performed at different speeds on the left and right, so that the thickness of the binder film before stretching needs to be different on the left and right. In casting film formation, the flow rate of the binder solution can be differentiated between the left and right sides by tapering the die. The tilt angle is preferably stretched so as to match the angle formed between the transmission axis of the two polarizing plates bonded to both sides of the liquid crystal cell constituting the liquid crystal display device and the vertical or horizontal direction of the liquid crystal cell. A normal inclination angle is 45 °. However, recently, transmissive, reflective, and transflective liquid crystal display devices have been developed that are not necessarily 45 °, and it is preferable that the stretching direction can be arbitrarily adjusted in accordance with the design of the liquid crystal display device.
As described above, a binder film that is obliquely stretched by 10 to 80 ° with respect to the MD direction of the polarizing film is produced.

  In the rubbing method, a rubbing treatment method widely adopted as a liquid crystal alignment treatment process of a liquid crystal display device can be applied. That is, orientation is obtained by rubbing the surface of the film in a certain direction using paper, gauze, felt, rubber, nylon, or polyester fiber. Generally, it is carried out by rubbing several times using a cloth in which fibers having a uniform length and thickness are planted on average. It is preferable to carry out using a rubbing roll in which the roundness, cylindricity, and deflection (eccentricity) of the roll itself are all 30 μm or less. The film wrap angle on the rubbing roll is preferably 0.1 to 90 °. However, as described in JP-A-8-160430, a stable rubbing treatment can be obtained by winding 360 ° or more. When rubbing a long film, the film is preferably transported at a speed of 1 to 100 m / min in a constant tension state by a transport device. The rubbing roll is preferably rotatable in the horizontal direction with respect to the film traveling direction for setting an arbitrary rubbing angle. It is preferable to select an appropriate rubbing angle in the range of 0 to 60 °. When used in a liquid crystal display device, 40 to 50 ° is preferable, and 45 ° is more preferable.

  It is preferable to arrange protective films on both surfaces of the polarizing film, and it is preferable to use a part of the roll-shaped optical compensation film as the protective film on one surface. For example, protective film / polarizing film / second optical anisotropic layer / first optical anisotropic layer, or protective film / polarizing film / second optical anisotropic layer / alignment film / first optical anisotropic layer The laminated body laminated | stacked in order is preferable. The polarizing film and the surface side of the first optical anisotropic layer may be bonded together. An adhesive can be used for bonding. Polyvinyl alcohol resins (including modified polyvinyl alcohols with acetoacetyl groups, sulfonic acid groups, carboxyl groups, and oxyalkylene groups) and boron compound aqueous solutions can be used as adhesives. A polyvinyl alcohol resin is preferred. The thickness of the adhesive layer is preferably in the range of 0.01 to 10 μm after drying, and more preferably in the range of 0.05 to 5 μm. For example, a light diffusion film or an antiglare film may be bonded to the surface of the polarizing plate.

(Liquid crystal display device)
The liquid crystal display device of the present invention has a liquid crystal cell and the polarizing plate of the present invention.
The polarizing plate of the present invention obtained by laminating the optical compensation film and the polarizing film is particularly advantageously used for a transmissive liquid crystal display device.
In the liquid crystal display device of the present invention, the liquid crystal layer of the liquid crystal cell preferably satisfies at least one of the following formulas (10) to (12).
1 ≦ Re ₁ c450 (0 °) / Re ₁ c650 (0 °) ≦ 1.25 (10)
1 ≦ Re ₁ c450 (40 °) / Re ₁ c650 (40 °) ≦ 1.25 (11)
1 ≦ Re ₁ c450 (−40 °) / Re ₁ c650 (−40 °) ≦ 1.25 (12)
However, the Re retardation value in a state in which the fast axis of the liquid crystal cell measured with light of wavelength λ (nm) is tilted by θ ° with respect to the normal direction with the axis of rotation as the rotation axis is defined as Re ₁ cλ (θ) ( When the values of Re ₁ cλ (θ) and Re ₁ cλ (−θ) are different, the magnitude is determined so that Re ₁ cλ (θ)> Re ₁ cλ (−θ).
Moreover, it is preferable that the first optical anisotropic layer and the liquid crystal layer of the liquid crystal cell have optical characteristics satisfying at least one of the following mathematical formulas (13) to (15).
0.9 <{(Re ₁ c450 (0 °) / Re ₁ c650 (0 °)) / (Re ₁ 450 (0 °) / Re ₁ 650 (0 °))} <1.1 Formula ( 13)
0.9 <{(Re ₁ c450 (40 °) / Re ₁ c650 (40 °)) / (Re ₁ 450 (40 °) / Re ₁ 650 (40 °))} <1.1 Formula ( 14)
0.9 <{(Re ₁ c450 (−40 °) / Re ₁ c650 (−40 °)) / (Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °))} <1.1. ..Formula (15)
The liquid crystal display device of the present invention will be described below with reference to the drawings. However, the liquid crystal display device of the present invention is not limited to this configuration.

<Transmission type liquid crystal display device>
The transmissive liquid crystal display device includes a liquid crystal cell and two polarizing plates disposed on both sides thereof.
The polarizing plate includes a polarizing film and two transparent protective films disposed on both sides thereof. The liquid crystal cell carries a liquid crystal between two electrode substrates.
One optical compensation film of the present invention is disposed between the liquid crystal cell and one polarizing plate, or two optical compensation films are disposed between the liquid crystal cell and both polarizing plates.
The polarizing plate of the present invention may be used as at least one of the two polarizing plates arranged on both sides of the liquid crystal cell. In this case, the polarizing plate of the present invention is arranged so that the optical compensation film is on the liquid crystal cell side.
The liquid crystal cell is preferably one of OCB, ECB, IPS, FFS, and TN.
The OCB mode liquid crystal cell is a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between an upper portion and a lower portion of the liquid crystal cell. Liquid crystal display devices using bend alignment mode liquid crystal cells are disclosed in US Pat. Nos. 4,583,825 and 5,410,422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. For this reason, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

  In the IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied. In the IPS mode, black is displayed when no electric field is applied, and the transmission axes of the pair of upper and lower polarizing plates are orthogonal. A method of reducing leakage light at the time of black display in an oblique direction and improving a viewing angle using an optical compensation film is disclosed in JP-A-10-54982, JP-A-11-202323, and JP-A-9-292522. No. 11-133408, No. 11-305217, No. 10-307291, and the like.

In the TN mode liquid crystal cell, when no voltage is applied, the rod-like liquid crystal molecules are substantially horizontally aligned and twisted to 60 to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.
The Δn × d value of the OCB mode, ECB mode, and TN mode liquid crystal cells is preferably 50 to 1,000 nm, and more preferably 300 to 1,000 nm. A reflective or transmissive liquid crystal cell is preferred. It is preferable to express the color with RGB pixels, and the cell gap of the RGB pixels may be different for each pixel. Further, the voltage applied to each pixel may be different.
Among these, the liquid crystal cell is preferably a bend alignment liquid crystal cell.

-Bend alignment liquid crystal cell-
The bend alignment liquid crystal cell is a liquid crystal cell in which a bend alignment including a twist is formed at the center of the liquid crystal cell when a voltage is applied.
FIG. 1 is a cross-sectional view schematically showing the alignment of the liquid crystal compound in the bend alignment liquid crystal cell. As shown in FIG. 1, the bend alignment liquid crystal cell has a structure in which a liquid crystal compound 11 is sealed between an upper substrate 14a and a lower substrate 14b. The liquid crystal compound 11 used in the bend alignment liquid crystal cell generally has a positive dielectric anisotropy, and rod-like liquid crystal molecules 11a to 11j are preferable. The upper substrate 14a and the lower substrate 14b of the liquid crystal cell have alignment films 12a and 12b and electrode layers 13a and 13b, respectively. The alignment film has a function of aligning the rod-like liquid crystal molecules 11a to 11j. RD is the rubbing direction of the alignment film. The electrode layer has a function of applying a voltage to the rod-like liquid crystal molecules 11a to 11j.

  When the applied voltage of the bend alignment liquid crystal cell is low, the rod-like liquid crystal molecules 11a to 11e on the upper substrate 14a side and the rod-like liquid crystal molecules 11f to 11j on the lower substrate 14b side of the liquid crystal cell are shown in FIG. Is oriented in the opposite direction (vertically symmetrical). Further, the rod-like liquid crystal molecules 11a, 11b, 11i, and 11j in the vicinity of the substrates 14a and 14b are aligned in a substantially horizontal direction, and the rod-like liquid crystal molecules 11d to 11g in the center of the liquid crystal cell are aligned in a substantially vertical direction.

  As shown in on in FIG. 1, when the applied voltage is high, the rod-like liquid crystal molecules 11a and 11j in the vicinity of the substrates 14a and 14b remain substantially horizontally aligned. Further, the rod-like liquid crystal molecules 11e and 11f in the central part of the liquid crystal cell remain aligned substantially vertically. The alignment changes with increasing voltage in the rod-like liquid crystalline molecules 11b, 11c, 11d, 11g, 11h, and 11i located between the substrate and the central portion of the liquid crystal cell, which are perpendicular to the off state. Orient. However, the rod-like liquid crystalline molecules 11a to 11e on the upper substrate 14a side of the liquid crystal cell and the rod-like liquid crystalline molecules 11f to 11j on the lower substrate 14b side are oriented in opposite directions (vertically symmetrical). It is the same as the state.

-Polarizing plate-
FIG. 2 is a schematic diagram showing a polarizing plate. The polarizing plate shown in FIG. 2 includes a laminated body of at least a first optical anisotropic layer 31, a second optical anisotropic layer 33, and a polarizing film. The first optically anisotropic layer 31 is preferably made of discotic liquid crystal compounds 31a to 31e, and the second optically anisotropic layer 33 is preferably made of a cellulose acylate film. The polarizing plate shown in FIG. 2 has an alignment film 32 between the first optical anisotropic layer 31 and the second optical anisotropic layer 33. The discotic liquid crystal compounds 31a to 31e of the first optically anisotropic layer 31 are planar molecules. The discotic liquid crystal compounds 31a to 31e have only one plane, that is, a disk plane in the molecule. The disk surface is inclined with respect to the surface of the second optical anisotropic layer 33. The angle (tilt angle) between the disc surface and the second optically anisotropic layer surface increases as the distance from the discotic liquid crystal compound compound and the alignment film increases. The average inclination angle is preferably in the range of 15 to 50 °. As shown in FIG. 2, when the tilt angle is changed, the viewing angle widening function of the polarizing plate is remarkably improved. Further, the polarizing plate with the tilt angle changed has a function of preventing the reversal of the display image, the gradation change, or the occurrence of coloring. The average of the direction PL obtained by orthogonally projecting the disc surface normal line NL of the discotic liquid crystal compounds 31 a to 31 e onto the second optical anisotropic layer 33 is in an antiparallel relationship with the rubbing direction RD of the alignment film 32.

  The preferred functions of the present invention include an average direction of orthogonal projection of the normal of the disc surface of the discotic liquid crystal compound onto the second optical anisotropic layer, and an in-plane slow axis SA of the second optical anisotropic layer 33. The angle is substantially 45 °. Therefore, in the manufacturing process of the polarizing plate, the angle θ between the rubbing direction RD of the alignment film 32 and the in-plane slow axis SA of the second optical anisotropic layer may be adjusted to be substantially 45 °. Further, in the present invention, the second optical anisotropic is performed so that the in-plane slow axis SA of the second optical anisotropic layer and the in-plane transmission axis TA of the polarizing film 34 are substantially parallel or substantially perpendicular. A conductive layer and a polarizing film are disposed. In the polarizing plate shown in FIG. 2, one second optically anisotropic layer is arranged in parallel. In principle, the in-plane slow axis SA of the second optical anisotropic layer 33 corresponds to the extending direction of the second optical anisotropic layer. The in-plane transmission axis TA of the polarizing film 34 corresponds in principle to a direction perpendicular to the extending direction of the polarizing film.

-Light diffusion film-
The light diffusing or antiglare film is suitably used for the liquid crystal display device and exhibits a light diffusing function. FIG. 3 is a schematic cross-sectional view showing a typical form of a light diffusion film.
The light diffusing film 1 shown in FIG. 3 includes a transparent base film 2 and a light diffusing layer including, for example, a first light transmitting fine particle 41 and a second light transmitting fine particle 42 in the light transmitting resin 40. 3 is laminated. Here, two types of light-transmitting fine particles having different particle size distribution peaks (differing in refractive index) will be described, but two particle size distribution peaks of the same type (with the same refractive index) are used. The translucent fine particle which it has may be used, and one kind of translucent fine particle may be used.

  The first translucent fine particles 41 are composed of a translucent resin, for example, silica fine particles (average particle diameter 1.0 μm, refractive index 1.51), and the second translucent fine particles 42 are translucent. For example, styrene beads (average particle diameter 3.5 μm, refractive index 1.61). The light diffusing function is obtained by the difference in refractive index between the translucent fine particles 41 and 42 and the translucent resin 40. The difference in refractive index is preferably 0.02 to 0.15. If the difference in refractive index is less than 0.02, the light diffusion effect may not be obtained. When the refractive index difference is larger than 0.15, the light diffusibility is too high, and the whole film may be whitened. The refractive index difference is preferably 0.03 to 0.13, and more preferably 0.04 to 0.10.

  When the polarizing film is used in a liquid crystal display device, it is preferable to provide an antireflection layer on the viewing side surface. The antireflection layer may also be used as a protective layer on the viewing side of the polarizing film. From the viewpoint of suppressing a change in tint depending on the viewing angle of the liquid crystal display device, the internal haze of the antireflection layer is preferably 50% or more. The antireflection layer is described in JP-A Nos. 2001-33783, 2001-343646, and 2002-328228.

[Bent alignment type liquid crystal display]
FIG. 4 is a schematic cross-sectional view showing a bend alignment type liquid crystal display device according to the present invention. The liquid crystal display device shown in FIG. 4 includes a bend alignment liquid crystal cell 10, a pair of polarizing plates 31 </ b> A to 34 </ b> A and 31 </ b> B to 34 </ b> B and a backlight BL arranged on both sides of the liquid crystal cell. The bend alignment liquid crystal cell 10 corresponds to the liquid crystal cell shown in FIG. The upper and lower rubbing directions RD2 and RD3 of the bend alignment liquid crystal cell 10 are the same direction (parallel). The polarizing plate is formed by laminating a first optical anisotropic layer 31A (31B), a second optical anisotropic layer 33A (33B), and a polarizing film 34A (34B) in this order from the bend alignment liquid crystal cell 10 side. The rubbing directions RD1, RD4 of the discotic liquid crystal compounds of the first optically anisotropic layers 31A, 31B are in an antiparallel relationship with the rubbing directions RD2, RD3 of the liquid crystal cells facing each other. As described above, the rubbing directions RD1 and RD4 of the discotic liquid crystal compound are antiparallel to the average direction obtained by orthogonally projecting the normal line of the disc surface to the second optical anisotropic layer. The in-plane slow axes SA1 and SA2 of the second optical anisotropic layers 33A and 33B and the in-plane transmission axes TA1 and TA2 of the polarizing films 34A and 34B are substantially in the same plane as the rubbing directions RD1 and RD4 of the discotic liquid crystal compound. The angle is 45 °. The two polarizing films 34A and 34B are arranged so that the in-plane transmission axes TA1 and TA2 are orthogonal to each other (crossed Nicols).

Hereinafter, another example of the liquid crystal display device of the present invention will be described with reference to the drawings.
[ECB mode type liquid crystal display]
FIG. 5 is a schematic cross-sectional view showing an ECB mode type liquid crystal display device of the present invention. The ECB mode type liquid crystal display device shown in FIG. 5 includes a liquid crystal cell including a liquid crystal layer including a liquid crystal compound 51 and substrates 52A and 52B sandwiching the liquid crystal layer. The upper substrate 52A and the lower substrate 52B each have an alignment film (not shown) and an electrode layer (not shown). Polarizing films 56A and 56B are respectively disposed with the liquid crystal cell interposed therebetween. Between the polarizing films 56A and 56B and the liquid crystal cell, the first optical anisotropic layers 53A and 53B and the second optical anisotropic layers 54A and 54B are disposed, respectively. In addition to the first and second optical anisotropic layers, third optical anisotropic layers 55A and 55B may be further provided. The first and second optical anisotropic layers and the polarizing film are preferably integrated and used as an elliptically polarizing plate.
In addition, the first and second optically anisotropic layers may be incorporated into the liquid crystal display device as an integrated member, or may be incorporated as individual members. In addition, the first and second optically anisotropic layers are disposed between the liquid crystal cell and the polarizing film on the backlight side, even if disposed between the liquid crystal cell and the polarizing film on the display surface side. Also good.

  The transmission axes TA3 and TA4 of the polarizing films 56A and 56B are arranged so as to be orthogonal to each other and parallel to the slow axes SA3 and SA4 of the second optical anisotropic layers 54A and 54B, respectively.

The liquid crystal cell includes an upper substrate 52A and a lower substrate 52B and a liquid crystal layer sandwiched between them. An alignment film (not shown) is formed on the surface of the substrates 52 </ b> A and 52 </ b> B that contacts the liquid crystal compound 51 (hereinafter sometimes referred to as “inner surface”). The alignment film has a function of aligning the liquid crystal compound 51 by performing a rubbing treatment or the like. The rubbing direction RD6 of the upper substrate 52A and the rubbing direction RD7 of the lower substrate 52B are set in parallel, and the liquid crystal compound 51 is in a parallel orientation without a twist structure. In addition, on the inner surfaces of the substrates 52A and 52B, a transparent electrode (not shown) capable of applying a voltage to the liquid crystal layer made of the liquid crystal compound 51 is formed. The transparent electrode has a function of applying a voltage to the liquid crystalline compound 51. The transparent electrode is usually made of transparent indium tin oxide (ITO).
The liquid crystal material to be used is not particularly limited, but a liquid crystal material having a positive dielectric anisotropy is preferably used.

  In the present invention, the product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn is preferably 0.1 to 1.5 μm, and more preferably 0.12 to 0.9 μm. It is more preferable to set it to 0.15 to 0.5 μm. In these ranges, since the white display luminance is high and the black display luminance is low, a bright and high-contrast display device can be obtained. These optimum values are values in the transmission mode, and in the reflection mode, the optical path in the liquid crystal cell is doubled. Therefore, the value of the optimum Δn · d is about ½ of the above value.

  The liquid crystal display device having the above-described configuration exhibits a white display when no voltage is applied, and a normally white display where the transmittance is reduced and black is displayed when a high voltage is applied. Black display is obtained when the Re value of the optical compensation film matches the retardation value of the liquid crystal layer in the voltage application state.

  In a non-driving state in which a driving voltage is not applied to the respective transparent electrodes (not shown) of the substrates 52A and 52B, the liquid crystalline compound 51 in the liquid crystal layer is aligned substantially parallel to the surfaces of the substrates 52A and 52B. The resulting light changes its polarization state due to the birefringence effect of the liquid crystalline compound 51 and passes through the polarizing films 56A and 52B. At this time, the value of Δn · d of the liquid crystal layer is set within the above range so that the transmitted light is maximized. On the other hand, in a driving state in which a driving voltage is applied to a transparent electrode (not shown), the liquid crystalline compound 51 tends to be aligned perpendicular to the surfaces of the substrates 52A and 52B depending on the magnitude of the applied voltage. However, although it is substantially perpendicular to the substrate surface near the center between the substrates, it is oriented in a parallel direction near the substrate interface, and is continuously inclined toward the center. In such a state, it is difficult to obtain a complete black display. In addition, the average orientation of the tilted liquid crystal compound in the vicinity of the substrate interface changes depending on the angle to be observed, and the viewing angle dependency in which the transmittance and brightness change depending on the viewing angle occurs. Therefore, by first disposing an optical compensation film that compensates for the residual retardation of the liquid crystal layer in the vicinity of the substrate interface, a complete black display can be obtained and the front contrast ratio is improved.

[IPS mode type liquid crystal display]
FIG. 6 is a schematic cross-sectional view showing the IPS mode liquid crystal display device of the present invention. The IPS mode liquid crystal display device shown in FIG. 6 has a liquid crystal cell including a liquid crystal layer containing a liquid crystal compound 61 and substrates 62A and 62B sandwiching the liquid crystal layer. The upper substrate 62A and the lower substrate 62B each have an alignment film (not shown) and an electrode layer (not shown). Polarizing films 64A and 64B are disposed with the liquid crystal cell interposed therebetween. Between the polarizing films 64A and 64B and the liquid crystal cell, first optical anisotropic layers 63A and 63B and a second optical anisotropic layer (not shown) are arranged, respectively. The first and second optically anisotropic layers and the polarizing film are preferably integrated and used as an elliptically polarizing plate.
In addition, the first and second optically anisotropic layers may be incorporated into the liquid crystal display device as an integrated member, or may be incorporated as individual members. In addition, the first and second optically anisotropic layers are disposed between the liquid crystal cell and the polarizing film on the backlight side, even if disposed between the liquid crystal cell and the polarizing film on the display surface side. Also good.

  The transmission axes TA5 and TA6 of the polarizing films 64A and 64B are arranged so as to be orthogonal to each other and parallel to the slow axes SA7 and SA8 of the first optical anisotropic layers 63A and 63B, respectively.

  In the liquid crystal display device of FIG. 6, the liquid crystal cell includes an upper substrate 62A and a lower substrate 62B, and a liquid crystal layer sandwiched therebetween. An alignment film (not shown) is formed on the surfaces of the substrates 62A and 62B that are in contact with the liquid crystal layer, and the liquid crystalline compound 61 is aligned substantially parallel to the surfaces of the substrates 62A and 62B, and on the alignment film. The orientation direction of the liquid crystal molecules in the no-voltage application state or the low application state is controlled by the applied rubbing directions RD9 and RD10. An electrode (not shown) capable of applying a voltage to the liquid crystal molecules is formed on the inner surface of the substrate 62A or 62B.

  FIG. 7 is a cross-sectional view schematically showing the orientation of the liquid crystal compound in the IPS mode liquid crystal cell. Usually, a plurality of pixels are provided by matrix electrodes, but a part of one pixel is shown. A linear electrode 74 is formed inside a pair of transparent substrates 71A and 71B, and an alignment control film (not shown) is formed thereon. The rod-like liquid crystal compound 73 sandwiched between the substrates 71A and 71B is oriented so as to have a slight angle with respect to the longitudinal direction of the linear electrode 74 when no electric field is applied. In this case, the dielectric anisotropy of the liquid crystal is assumed to be positive. When the electric field 77 is applied, the liquid crystal compound 73 changes its direction in the electric field direction. The light transmittance can be changed by disposing the polarizing plates 71A and 71B at a predetermined angle. The angle formed by the electric field direction 77 with respect to the surface of the lower substrate 71B is preferably 20 degrees or less, and more preferably 10 degrees or less. That is, it is desirable that they are substantially parallel. Hereinafter, in the present invention, those below 20 degrees are generically expressed as a parallel electric field. Even if the linear electrode 74 is formed separately on the upper and lower substrates or formed only on one substrate, the effect does not change.

  As a liquid crystal material used for the IPS mode type liquid crystal display device, a nematic liquid crystal having a positive dielectric anisotropy Δε is preferable. The thickness (gap) of the liquid crystal layer was more than 2.8 μm and less than 4.5 μm. As described above, when the retardation (Δn · d) is more than 0.25 μm and less than 0.32 μm, a transmittance characteristic having almost no wavelength dependence within the visible light range can be obtained more easily. By the combination of the alignment film and the polarizing plate described later, the maximum transmittance can be obtained when the liquid crystalline molecules are rotated 45 degrees from the rubbing direction to the electric field direction. The thickness (gap) of the liquid crystal layer is controlled by polymer beads. Of course, the same gap can be obtained with glass bead fiber or resin columnar spacers. The liquid crystal material is not particularly limited as long as it is a nematic liquid crystal. As the value of the dielectric anisotropy Δε is larger, the driving voltage can be reduced, and as the refractive index anisotropy Δn is smaller, the thickness (gap) of the liquid crystal layer can be increased, and the liquid crystal sealing time is shortened. In addition, gap variation can be reduced.

[FFS mode type liquid crystal display]
The optical compensation film of the present invention can also be used in an FFS type liquid crystal display device having an FFS mode liquid crystal cell.
FIG. 8 is a cross-sectional view schematically showing the orientation of the liquid crystal compound in the FFS mode liquid crystal cell. Except for having the insulating layer 75 and the electrode 16 between the lower substrate 72B and the linear electrode 74, the configuration is the same as that of the IPS mode liquid crystal cell shown in FIG.
In the FFS mode liquid crystal display device, an insulating layer 75 is interposed between a rectangular electrode 16 and a slit-shaped linear electrode 74 corresponding to a structure in which a plurality of rod-shaped patterns are formed so as to be separated from each other. Compared with the IPS mode, the horizontal electric field is configured with a few angstroms (angstrom) interval, so the intensity of the horizontal electric field is high, and the horizontal electric field causes the upper part of the electrode to be There is an advantage that even liquid crystal molecules can be aligned.

[TN mode liquid crystal display]
The optical compensation film of the present invention can also be used for a TN liquid crystal display device having a TN mode liquid crystal cell. TN mode liquid crystal cells and TN type liquid crystal display devices have been well known for a long time. The optical compensation film used in the TN type liquid crystal display device is described in JP-A-3-9325, JP-A-6-148429, JP-A-8-50206, and JP-A-9-26572. is there. Moreover, it is described in Mori et al. (Jpn. J. Appl. Phys. Vol. 36 (1997) p143 and Jpn. J. Appl. Phys. Vol. 36 (1997) p1068).

Examples of the present invention will be described below, but the present invention is not limited to these examples.
Example 1
-Production of second optically anisotropic layer A-
-Preparation of cellulose acetate solution-
Each composition described in Table 1 was put into a mixing tank and stirred while heating to dissolve each composition to prepare a cellulose acetate solution.

  The obtained cellulose acetate solution (dope) was cast using a casting machine having a band having a width of 2 m and a length of 65 m. After the film surface temperature on the band reached 40 ° C., it was dried for 1 minute, peeled off, and then stretched 28% in the width direction using a tenter with a drying air of 140 ° C. Then, it dried for 20 minutes with 135 degreeC drying air, and produced the 2nd optically anisotropic layer A whose residual solvent amount is 0.3 mass%. The width of the second optical anisotropic layer A was 1,340 mm and the thickness was 88 μm.

-Measurement of optical characteristics of second optically anisotropic layer A-
About the produced 2nd optically anisotropic layer A, retardation Re was measured at each wavelength using KOBRA-ADH (made by Oji Scientific Instruments).
Re ₂ 450 (0) / Re ₂ 650 (0),
Re ₂ 450 (40) / Re ₂ 650 (40),
Re ₂ 450 (−40) / Re ₂ 650 (−40) is shown in Table 2.

-Saponification treatment of second optically anisotropic layer A-
One surface of the prepared second optically anisotropic layer A was coated with 25 ml / m ^{2 of} an isopropyl alcohol solution of 1.5 mol / L potassium hydroxide, allowed to stand at 25 ° C. for 5 seconds, and then washed with running water for 10 seconds. The surface of the film was dried by blowing air at 25 ° C. In this way, only one surface of the second optical anisotropic layer A was saponified.

-Preparation of alignment film coating solution-
An alignment film coating solution comprising the composition described below was prepared.
------------------------------------
-Modified polyvinyl alcohol having the following structural formula: 10 parts by mass-Water: 371 parts by mass-Methanol: 119 parts by mass-Glutaraldehyde (crosslinking agent): 0.5 parts by mass------------ ---------------------

-Formation of alignment film-
On the surface of the second optically anisotropic layer A subjected to the saponification treatment, the obtained alignment film coating solution was applied at 24 ml / m ² with a # 14 wire bar coater. The film was dried with warm air of 60 ° C. for 60 seconds and further with warm air of 90 ° C. for 150 seconds. Next, the formed film was rubbed in the direction of 45 ° with the stretching direction of the second optical anisotropic layer A (substantially coincident with the slow axis).

-Production of first optically anisotropic layer A and optical compensation film A-
--- Preparation of coating liquid-
Each composition was dissolved in the following methyl ethyl ketone to prepare a coating solution.
--------------------------------------
-400 parts by mass of methyl ethyl ketone-100 parts by mass of the discotic liquid crystal compound represented by the following structural formula (D-89)-0.4 parts by mass of the air interface alignment controller V- (1) shown below-Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Co., Ltd.) 3 parts by mass / sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass --------------------- ----------------

The said coating liquid was apply | coated with the wire bar of # 3.0 on the obtained alignment film. This was affixed to a metal frame and heated in a constant temperature bath at 95 ° C. for 2 minutes to align the discotic liquid crystal compound. Next, using a 120 W / cm ² high pressure mercury lamp at 80 ° C., ultraviolet rays were irradiated for 1 minute to polymerize the discotic liquid crystal compound. Then, it stood to cool to room temperature. Thus, the 1st optical anisotropic layer A was produced and the optical compensation film A was produced.

-Measurement of optical properties of first optical anisotropic layer A-
An alignment film is formed on glass by the same method as the alignment film forming method and the first optical anisotropic layer A manufacturing method, and the first optical anisotropic layer A is formed on the alignment film. Retardation Re was measured at each wavelength using KOBRA-ADH (manufactured by Oji Scientific Instruments).
Re ₁ 450 (0) / Re ₁ 650 (0),
Re ₁ 450 (40) / Re ₁ 650 (40),
Re ₁ 450 (−40) / Re ₁ 650 (−40) is shown in Table 2.

-Production of elliptically polarizing plate A-
A polarizing film was prepared by adsorbing iodine to a stretched polyvinyl alcohol film.
Next, the second optical anisotropic layer A side of the produced optical compensation film A was attached to one side of the polarizing film using a polyvinyl alcohol-based adhesive. The slow axis of the second optical anisotropic layer A and the transmission axis of the polarizing film were arranged in parallel. A commercially available cellulose triacetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) was saponified in the same manner as described above, and the other side of the polarizing film (the optical compensation film A was not attached) using a polyvinyl alcohol-based adhesive. Affixed to the side). Thus, the elliptically polarizing plate A was produced.

Example 1A
-Production of bend alignment liquid crystal cell A-
A polyimide film was provided as an alignment film on a glass substrate with an ITO electrode, and the alignment film was rubbed. The obtained two glass substrates were faced to each other so that the rubbing directions were parallel to each other, and the cell gap was set to 4.1 μm. A bend-aligned liquid crystal cell A was produced by injecting a liquid crystal compound (ZLI1132, manufactured by Merck & Co., Inc.) having Δn of 0.1396 into the cell gap.
For the bend alignment liquid crystal cell A, the retardation Re was measured using KOBRA-ADH (manufactured by Oji Scientific Instruments).
Re _l c450 (0) / Re _l c650 (0),
Re _l c450 (40) / Re _l c650 (40),
Re _l c450 (−40) / Re _l c650 (−40) is shown in Table 3.

-Production and evaluation of liquid crystal display device A-
The bend alignment liquid crystal cell A and the obtained two elliptically polarizing plates A were combined to produce a liquid crystal display device A as shown in FIG. The produced liquid crystal display device A was placed on the backlight, and a voltage was applied to the bend alignment liquid crystal cell A with a 55 Hz rectangular wave. While adjusting the voltage, a luminance meter (BM-5 manufactured by TOPCON) was used to determine the voltage with the smallest black luminance (front luminance). The voltage in the front direction of the panel (front V) and the color shift ΔC (u ′, v ′) between the azimuth angle 0 degree polar angle 60 degrees (u ′) and the azimuth angle 180 degrees polar angle 60 degrees (v ′). Asked. The results are shown in Table 3.
Furthermore, about the liquid crystal display device A of this invention, it measured using the brightness | luminance and the tint measuring apparatus about the grade of the tint change, and determined with the following reference | standard. The results are shown in Table 3.
A: Very good with no change in color.
Δ: Some color change slightly occurred.
X: The color change appeared remarkably.

(Example 2)
-Production of second optically anisotropic layer B-
100 parts by mass of cellulose acetate having an acetylation degree of 60.7 to 61.1%, 2.35 parts by mass of the following retardation increasing agent, 2.75 parts by mass of triphenyl phosphate and 2.20 parts by mass of biphenyl diphenyl phosphate, It melt | dissolved in 232.75 mass parts of methylene chloride, 42.57 mass parts of methanol, and 8.50 mass parts of n-butanol.

  The obtained dope was cast using a casting machine having a band having a width of 2 m and a length of 65 m. After the film surface temperature on the band reached 40 ° C., it was dried for 1 minute, peeled off, and then stretched 26% in the width direction with a drying air at 140 ° C. using a tenter. Then, it dried for 20 minutes with 135 degreeC drying air, and produced the 2nd optically anisotropic layer B whose residual solvent amount is 0.3 mass%. The width of the second optical anisotropic layer B was 1,340 mm and the thickness was 88 μm.

About the produced 2nd optically anisotropic layer B, retardation Re was measured at each wavelength using KOBRA-ADH (made by Oji Scientific Instruments).
Re ₂ 450 (0) / Re ₂ 650 (0),
Re ₂ 450 (40) / Re ₂ 650 (40),
Re ₂ 450 (−40) / Re ₂ 650 (−40) is shown in Table 2.

-Production of first optical anisotropic layer B and optical compensation film B-
On the obtained second optical anisotropic layer B, the first optical anisotropic layer B was produced in the same manner as in Example 1, and the optical compensation film B was produced.

-Production of elliptically polarizing plate B-
In the same manner as in Example 1, an elliptically polarizing plate B including the obtained optical compensation film B was produced.

(Example 2A)
-Production of bend alignment liquid crystal cell B-
The obtained elliptically polarizing plate B was attached to the bend alignment liquid crystal cell B in the same manner as in Example 1A to produce a liquid crystal display device B, and the retardation Re of the bend alignment liquid crystal cell B was evaluated in the same manner as in Example 1A. The results are shown in Table 3.

-Production and evaluation of liquid crystal display device B-
A liquid crystal display device B was produced in the same manner as in Example 1A and evaluated in the same manner as in Example 1A. The results are shown in Table 3.

(Example 3)
-Production of second optical anisotropic layer C-
In Example 1, in place of the second optically anisotropic layer A, the second optically anisotropic layer C, JP 2000 - a transparent protective film used in Example 1 described in 284124 JP used.
About the produced 2nd optically anisotropic layer C, retardation Re was measured at each wavelength using KOBRA-ADH (made by Oji Scientific Instruments).
Re ₂ 450 (0) / Re ₂ 650 (0),
Re ₂ 450 (40) / Re ₂ 650 (40),
Re ₂ 450 (−40) / Re ₂ 650 (−40) is shown in Table 2.

-Production of first optical anisotropic layer C and optical compensation film C-
In Example 1, except that the wire bar was changed to # 3.4, the first optical anisotropic layer C was produced in the same manner as in Example 1, and the optical compensation film C was produced.

-Production of elliptically polarizing plate C-
In the same manner as in Example 1, an elliptically polarizing plate C including the obtained optical compensation film C was produced.

(Example 3A)
-Production of ECB liquid crystal cell C-
The ECB liquid crystal cell C has a cell gap of 3.5 μm, a liquid crystal material having a positive dielectric constant anisotropic layer is sealed between the substrates by dropping, and Δn · d of the liquid crystal layer 7 is 300 nm. The liquid crystal material has a positive dielectric anisotropy, a refractive index anisotropy, Δn = 0.0854 (589 nm, 20 ° C.), and a liquid crystal of about Δε = + 8.5 (MLC-9100 manufactured by Merck). ECB liquid crystal cell C was produced.
For the obtained ECB liquid crystal cell C, the retardation Re was measured at each wavelength using KOBRA-ADH (manufactured by Oji Scientific Instruments).
Re ₁ c450 (0) / Re ₁ c650 (0),
Re ₁ c450 (40) / Re ₁ c650 (40),
Re ₁ c450 (−40) / Re ₁ c650 (−40) is shown in Table 3.

-Production and evaluation of liquid crystal display device C-
A liquid crystal display device C was produced in the same manner as in Example 1A and evaluated in the same manner as in Example 1A. The results are shown in Table 3.

Example 4
-Production and evaluation of second optically anisotropic layer D-
The second optically anisotropic layer D was prepared in the same manner as in Example 1, and the retardation Re was evaluated in the same manner as in Example 1. The results are shown in Table 2.

-Production of first optical anisotropic layer D and optical compensation film D-
In Example 1, the first optical anisotropic layer D of Example 4 was produced in the same manner as in Example 1 except that the rubbing direction of the first optical anisotropic layer A was parallel to the longitudinal direction of the roll. Then, an optical compensation film D was prepared, and the retardation Re of the first optical anisotropic layer D was evaluated. The results are shown in Table 2.

-Production of elliptical polarizing plate D-
Example 1 including the optical compensation film D obtained in the same manner as in Example 1 except that the slow axis in the second optically anisotropic layer and the transmission axis of the polarizer were bonded to each other at right angles. The elliptically polarizing plate D of Example 4 was produced.

(Example 4A)
-Production of TN alignment liquid crystal cell D-
The TN alignment liquid crystal cell D has a cell gap (d) of 5 μm, a liquid crystal material having a positive dielectric constant anisotropic layer is sealed between the substrates by drop injection, and Δnd is 420 nm (Δn is the refractive index of the liquid crystal material) anisotropy). The twist angle of the liquid crystal cell liquid crystal layer was 90 °, and the absorption axis of the elliptically polarizing plate D obtained in Example 4 coincided with the upper and lower substrate rubbing directions of the liquid crystal cell above and below the cell as shown in FIG. Thus, the elliptically polarizing plate D was bonded through an adhesive to prepare a TN-aligned liquid crystal cell D.
About the produced TN alignment liquid crystal cell D, retardation Re was measured at each wavelength using KOBRA-ADH (made by Oji Scientific Instruments).
Re ₁ c450 (0) / Re ₁ c650 (0),
Re ₁ c450 (40) / Re ₁ c650 (40),
Re ₁ c450 (−40) / Re ₁ c650 (−40) is shown in Table 2.

-Production and evaluation of liquid crystal display device D-
A liquid crystal display device D was produced in the same manner as in Example 1A and evaluated in the same manner as in Example 1A. The results are shown in Table 3.

( Reference Example 5)
-Production of second optical anisotropic layer E-
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.

-Cellulose acetate solution composition-
----------------------------------
Cellulose acetate with an acetylation degree of 60.9% (polymerization degree 300, Mn / Mw = 1.5) 100 parts by mass Triphenyl phosphate (plasticizer) 7.8 parts by mass Biphenyldiphenyl phosphate (plasticizer) 9 parts by mass-Methylene chloride (first solvent) 300 parts by mass-Methanol (second solvent) 54 parts by mass-1-butanol (third solvent) 11 parts by mass ------------- ---------------------

  In another mixing tank, 16 parts by mass of the following retardation increasing agent A, 8 parts by mass of the following retardation increasing agent B, 0.28 parts by mass of silicon dioxide fine particles (average particle size: 0.1 μm), 80 parts by mass of methylene chloride And 20 parts by mass of methanol were added and stirred while heating to prepare a retardation increasing agent solution (and a fine particle dispersion). The dope was prepared by mixing 45 parts by mass of the retardation increasing agent solution with 474 parts by mass of the cellulose acetate solution and stirring sufficiently.

The obtained dope was cast using a casting machine having a band having a width of 2 m and a length of 65 m. A film having a residual solvent amount of 15% by mass was stretched laterally at a stretch ratio of 20% using a tenter under the conditions of 130 ° C., held at 50 ° C. for 30 seconds with the stretched width, and then the clip was removed. A cellulose acetate film was prepared. The amount of residual solvent at the end of stretching was 5% by mass, and was further dried to produce a second optical anisotropic layer E made of a film having a residual solvent amount of less than 0.1% by mass. In addition, Tg of the used cellulose acylate is 140 degreeC. The resulting cellulose acetate film had a thickness of 88 μm.
About the produced 2nd optically anisotropic layer E, retardation Re was measured at each wavelength using KOBRA-ADH (made by Oji Scientific Instruments).
Re ₂ 450 (0) / Re ₂ 650 (0),
Re ₂ 450 (40) / Re ₂ 650 (40),
Re ₂ 450 (−40) / Re ₂ 650 (−40) is shown in Table 2.

-Production of first optical anisotropic layer E and optical compensation film E-
An alignment film was formed on one surface of the produced second optically anisotropic layer E in the same manner as in Example 1. Next, a coating liquid containing a rod-like liquid crystal compound having the following composition is prepared, and the optical compensation is carried at 20 m / min by rotating the wire bar # 5.0 in the same direction as the film carrying direction at 391 revolutions. The coating solution was continuously applied to the alignment film surface of the film.
The solvent is dried in a process of continuously heating from room temperature to 90 ° C., and then, in the 90 ° C. drying zone, the film surface wind speed of the optically anisotropic layer is 2.5 m / sec for about 90 seconds. The rod-like liquid crystalline compound was aligned by heating. Next, the film is conveyed to a drying zone at 80 ° C., and the surface temperature of the film is about 80 ° C., and an ultraviolet ray irradiation device (ultraviolet lamp: output 160 W / cm ² , emission length 1.6 m) is used to emit ultraviolet rays having an illuminance of 600 mW. Was irradiated for 4 seconds to advance the cross-linking reaction, and the rod-like liquid crystal compound was fixed to the alignment. Then, it was allowed to cool to room temperature and wound into a cylindrical shape to form a roll. Thus, the 1st optical anisotropic layer E was produced and the optical compensation film E was produced.

-Preparation of coating liquid containing rod-shaped liquid crystal compound-
The following compositions were dissolved in the following methyl ethyl ketone to prepare a coating solution containing a rod-like liquid crystal compound.
――――――――――――――――――――――――――――――――――――
-100 parts by mass of the following rod-like liquid crystalline compound-Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 3 parts by mass-Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass-Fluorine series described below 0.2 parts by mass of polymer 2 parts by mass of the following pyridinium salt 198 parts by mass of methyl ethyl ketone ――――――――――――――――――――――――――――――― ―――――

Rod-shaped liquid crystal compound

Fluoropolymer

Pyridinium salt

A part of the produced roll-shaped first optical anisotropic layer E was cut out and used as a sample. Only the optically anisotropic layer containing the rod-like liquid crystalline compound was peeled from the sample, and the optical properties were measured. It was confirmed that an optically anisotropic layer in which rod-like liquid crystal molecules were aligned substantially perpendicular to the film surface was formed.
About the produced 1st optical anisotropic layer E, retardation Re was measured at each wavelength using KOBRA-ADH (made by Oji Scientific Instruments).
Re ₁ 450 (40) / Re ₁ 650 (40),
Re ₁ 450 (−40) / Re ₁ 650 (−40) is shown in Table 2.
Moreover, Re ₁ 450 (0) and Re ₁ 650 (0) were both 0 nm.

-Production of elliptical polarizing plate E-
In the same manner as in Example 1, an elliptically polarizing plate E including the obtained optical compensation film E was produced.

( Reference Example 5A)
-Fabrication and evaluation of IPS mode liquid crystal cell E-
On one glass substrate, electrodes were arranged so that the distance between adjacent electrodes was 20 μm, and a polyimide film was provided as an alignment film thereon, and a rubbing treatment was performed. A polyimide film was provided on one surface of a separately prepared glass substrate, and a rubbing treatment was performed to obtain an alignment film. On the top and bottom of the cell, the elliptically polarizing plate E was bonded via an adhesive so that the absorption axis of the elliptically polarizing plate E produced in Reference Example 5 coincided with the upper and lower substrate rubbing directions of the liquid crystal cell. The two glass substrates were laminated and bonded so that the alignment films were opposed to each other, the cell gap (d) was 3.9 μm, and the rubbing directions of the two glass substrates were parallel. Next, a nematic liquid crystal composition having a refractive index anisotropy (Δn) of 0.0769 and a dielectric anisotropy (Δε) of 4.5 was sealed to produce a horizontally aligned IPS mode liquid crystal cell E. . The value of Δn · d of the liquid crystal layer was 300 nm. In the same manner as in Example 1, the retardation Re of the IPS mode liquid crystal cell E was evaluated. The results are shown in Table 3.

-Production and evaluation of liquid crystal display device E-
A liquid crystal display device E was produced in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 3.

(Comparative Example 1)
-Production and evaluation of second optically anisotropic layer F-
The second optically anisotropic layer F was produced in the same manner as in Example 1, and the retardation Re was evaluated in the same manner as in Example 1.
Re ₂ 450 (0) / Re ₂ 650 (0),
Re ₂ 450 (40) / Re ₂ 650 (40),
Re ₂ 450 (−40) / Re ₂ 650 (−40) is shown in Table 2.

-Production of first optical anisotropic layer F and optical compensation film F-
--- Preparation of coating liquid-
The following composition was dissolved in the following methyl ethyl ketone to prepare a coating solution.
-----------------------------------
204 parts by mass of methyl ethyl ketone 91 parts by mass of a discotic liquid crystal compound represented by the above structural formula (D-89) 9 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) Butyrate (CAB531-1, manufactured by Eastman Chemical Co.) 1 part by mass / photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 3 parts by mass / sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 mass Part ----------------------------------

-Production of first optical anisotropic layer F and optical compensation film F-
The coating solution obtained on the alignment film was applied with a wire bar # 3.4. This was affixed to a metal frame and applied for 2 minutes in a thermostatic bath at 130 ° C. to align the discotic liquid crystal compound. Next, using a 120 W / cm ² high-pressure mercury lamp at 110 ° C., the discotic liquid crystal compound was polymerized by irradiation with ultraviolet rays for 1 minute. Then, it stood to cool to room temperature. Thus, the 1st optical anisotropic layer F was produced and the optical compensation film F was produced.

An alignment film is produced on the glass in the same manner as in Example 1, the first optical anisotropic layer F is formed on the alignment film, and retardation Re using KOBRA-ADH (manufactured by Oji Scientific Instruments). Was measured.
Re ₁ 450 (0) / Re ₁ 650 (0),
Re ₁ 450 (40) / Re ₁ 650 (40),
Re ₁ 450 (−40) / Re ₁ 650 (−40) is shown in Table 2.

-Production of elliptical polarizing plate F-
An elliptically polarizing plate F including the optical compensation film F obtained by the same method as in Example 1 was produced.

(Comparative Example 1A)
-Production of bend alignment liquid crystal cell F-
The elliptically polarizing plate F obtained in Comparative Example 1 was attached to the bend-aligned liquid crystal cell F in the same manner as in Example 1A to produce a liquid crystal display device F, which was evaluated in the same manner as in Example 1A. The results are shown in Table 3.

(Comparative Example 2)
-Production and evaluation of second optically anisotropic layer G-
The second optically anisotropic layer G of Comparative Example 2 was produced in the same manner as in Example 2, and the retardation Re was evaluated in the same manner as in Example 2.
Re ₂ 450 (0) / Re ₂ 650 (0),
Re ₂ 450 (40) / Re ₂ 650 (40),
Re ₂ 450 (−40) / Re ₂ 650 (−40) is shown in Table 2.

-Production of first optical anisotropic layer G and optical compensation film G-
In the same manner as in Comparative Example 1, the first optical anisotropic layer G and the optical compensation film G of Comparative Example 2 were produced, and the retardation Re was evaluated in the same manner as in Comparative Example 1.
Re ₁ 450 (0) / Re ₁ 650 (0),
Re ₁ 450 (40) / Re ₁ 650 (40),
Re ₁ 450 (−40) / Re ₁ 650 (−40) is shown in Table 2.

-Production of elliptically polarizing plate G-
An elliptically polarizing plate G including the optical compensation film F of the second optical anisotropic layer G of Comparative Example 2 and the first optical anisotropic layer F of Comparative Example 1 was produced.

(Comparative Example 2A)
-Production and evaluation of liquid crystal display device G-
In the same manner as in Example 1, the elliptically polarizing plate G of Comparative Example 2 was attached to the bend-aligned liquid crystal cell A to produce a liquid crystal display device G, which was evaluated in the same manner as in Example 1. The results are shown in Table 3.

In Table 2, represented by the numbers 1-2 in the upper column and (a)-(c) in the lower column,
1 (a) represents Re ₁ 450 (0) / Re ₁ 650 (0) described in Formula (1),
1 (b) represents Re ₁ 450 (40) / Re ₁ 650 (40) described in Equation (2),
1 (c) represents Re ₁ 450 (−40) and Re ₁ 650 (−40) described in Formula (3),
2 (a) represents Re ₂ 450 (0) / Re ₂ 650 (0) described in Formula (4),
2 (b) represents Re ₂ 450 (40) / Re ₂ 650 (40) described in Equation (5),
2 (c) represents Re ₂ 450 (−40) / Re ₂ 650 (−40) described in Formula (6).

In Table 3, represented by numbers 3 to 4 in the upper column and (a) to (c) in the lower column,
3 (a) represents Re ₁ c450 (0) / Re ₁ c650 (0) described in Formula (10),
3 (b) represents Re ₁ c450 (40) / Re ₁ c650 (40) described in Equation (11),
3 (c) represents Re ₁ c450 (−40) / Re ₁ c650 (−40) described in Formula (12),
4 (a) represents {(Re ₁ c450 (0 °) / Re ₁ c650 (0 °)) / (Re ₁ 450 (0 °) / Re ₁ 650 (0 °))} described in Equation (13)} That is, 3 (a) / 1 (a) is represented,
4 (b) is represented by the equation (14) {(Re ₁ c450 (40 °) / Re ₁ c650 (40 °)) / (Re ₁ 450 (40 °) / Re ₁ 650 (40 °))} That is, 3 (b) / 1 (b) is represented,
4 (c) represents {(Re ₁ c450 (−40 °) / Re ₁ c650 (−40 °)) / (Re ₁ 450 (−40 °) / Re ₁ 650 (−40) described in Equation (15). °))}, ie, 3 (c) / 1 (c).

From the results of Tables 2 and 3, the liquid crystal display device of Example 1A~ Example 4 A, the liquid crystal display device of Comparative Example 1A and Comparative Example 2A, the retardation Re of the first optically anisotropic layer 1 The values of (a) to (c) and the values of 2 (a) to (c) of the retardation Re of the second optical anisotropic layer are included in a preferable range derived from the mathematical formula, As a result, it was found that a good liquid crystal display with little color change can be obtained.
The liquid crystal display device of Example 1A~ Example 4 A, to the liquid crystal display device of Comparative Example 1A and Comparative Example 2A, the value of 3 of the retardation Re of the liquid crystal layer of the liquid crystal cell (a) ~ (c) And the values of 4 (a) to (c) of the retardation Re of the liquid crystal layer of the liquid crystal cell are included in a preferable range derived from the formula, and as a result, the front V and the color shift are extremely good. It was confirmed that the viewing angle dependency and the wavelength dependency were improved.

  The optical compensation film, polarizing plate and liquid crystal display device of the present invention can be suitably used for optical devices such as mobile phones, personal computer monitors and televisions.

FIG. 1 is a cross-sectional view schematically showing the alignment of the liquid crystal compound in the bend alignment liquid crystal cell. FIG. 2 is a schematic view showing the polarizing plate of the present invention. FIG. 3 is a schematic cross-sectional view showing a typical form of a light diffusion film. FIG. 4 is a schematic cross-sectional view showing a bend alignment type liquid crystal display device of the present invention. FIG. 5 is a schematic cross-sectional view showing an ECB mode type liquid crystal display device of the present invention. FIG. 6 is a schematic cross-sectional view showing the IPS mode liquid crystal display device of the present invention. FIG. 7 is a cross-sectional view schematically showing the orientation of the liquid crystal compound in the IPS mode liquid crystal cell. FIG. 8 is a cross-sectional view schematically showing the orientation of the liquid crystal compound in the FFS mode liquid crystal cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light diffusion film 2 Transparent base film 3 Light diffusion layer 10 Bend alignment liquid crystal cell 11, 51, 73 Liquid crystalline compound 11a-11j Rod-like liquid crystalline molecule 12a, 12b Alignment film 13a, 13b Electrode layer 14a, 52A, 72A Upper board 14b, 52B, 72B Lower substrate 31, 31A, 31B, 53A, 53B First optical anisotropic layer 31a-31e Discotic liquid crystal compound 32 Alignment film 33, 33A, 33B, 54A, 54B Second optical anisotropic layer 34, 34A, 34B, 56A, 56B Polarizing film 40 Translucent resin 41 First translucent fine particles 42 Second translucent fine particles 55A, 55B Third optically anisotropic layer 71A Upper polarizing plate 71B Lower side Polarizing plate 74 Linear electrode 75 Insulating layer 76 Electrode 77 Electric field direction NL Normal of disc surface of discotic compound PL Normal of disc surface Orthogonal projection direction RD to second optically anisotropic layer plane, RD1～RD10 rubbing direction SA, SA1~SA8 plane slow axis TA, TA1~TA6 plane transmission axis BL backlight

Claims (6)

It comprises at least a first optically anisotropic layer and a second optically anisotropic layer, and the first optically anisotropic layer comprises a discotic liquid crystal compound , and the following formulas (1) to (3) An optical compensation film satisfying at least one of the above, wherein the discotic liquid crystal compound is represented by the following general formula (DII).
1 ≦ Re ₁ 450 (0 °) / Re ₁ 650 (0 °) ≦ 1.25 (1)
1 ≦ Re ₁ 450 (40 °) / Re ₁ 650 (40 °) ≦ 1.25 (2)
1 ≦ Re ₁ 450 (−40 °) / Re ₁ 650 (−40 °) ≦ 1.25 (3)
However, in the above formulas (1) to (3), it was tilted by θ ° with respect to the normal direction with the slow axis of the first optically anisotropic layer as the rotation axis, measured with light of wavelength λ (nm). If the value of the Re retardation value in the state is defined as _{Re 1 λ (θ) (Re} 1 λ (θ) and Re ₁ λ (-θ) are _{different, Re 1 λ (θ)>} Re 1 λ (- The size is determined so that θ).
However, the general formula ^{(DII), Y 31, Y} 32 and ^{Y 33} are both represent methylol down ^{unsubstituted,} R ^{31, R 32} and ^{R 33} are the same, the following general formula (DiI- R).
In the general formula ^{(DII-R), A 31} and ^{A 32} are both represent a nitrogen atom, ^{X 3} represents SansoHara ^{child, Q 31} is, 1,4 having a fluorine atom as a substituent - represents either a phenylene group and a 1,3-phenylene group, n3 represents ^1, L 31 is, * - O -, * - O-CO-, * -O-CO-O-, and * —CH ₂ — ( wherein, * represents a position bonded to the Q ³¹ side), and L ³² represents —O— , —C (═O) — , —CH ₂ —, —CH. ═CH— and —C≡C—, and a divalent linking group selected from the group consisting of these, and Q ³² represents either a polymerizable group or a hydrogen atom. The optical compensation film according to claim 1, wherein the second optically anisotropic layer is made of a cellulose acylate film. A polarizing plate having a polarizing film and the optical compensation film according to claim 1 on at least one side of the polarizing film. A liquid crystal display device comprising a liquid crystal cell and the polarizing plate according to claim 3. The liquid crystal display device according to claim 4, wherein the liquid crystal layer of the liquid crystal cell has optical characteristics satisfying at least one of the following formulas (10) to (12).
1 ≦ Re ₁ c450 (0 °) / Re ₁ c650 (0 °) ≦ 1.25 (10)
1 ≦ Re ₁ c450 (40 °) / Re ₁ c650 (40 °) ≦ 1.25 (11)
1 ≦ Re ₁ c450 (−40 °) / Re ₁ c650 (−40 °) ≦ 1.25 (12)
However, the Re retardation value in a state in which the fast axis of the liquid crystal cell measured with light of wavelength λ (nm) is tilted by θ ° with respect to the normal direction with the rotation axis as the rotation axis is Re ₁ It is defined as cλ (θ) (Re ₁ cλ (θ) and Re ₁ If the value of cλ (−θ) is different, Re ₁ cλ (θ)> Re ₁ The magnitude is determined so as to be cλ (−θ)). The liquid crystal display device according to claim 4, wherein the liquid crystal cell is one of OCB, TN, ECB, IPS, and FFS.