JP2007219507A - Optical compensation film and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical compensation film for facilitating retardation control of an optical anisotropic layer by characteristics of a liquid crystal compound by regulating relationship of an alignment layer and the liquid crystal compound, and to provide a liquid crystal display device for improving contrast and reducing color shift depending on a visual angle direction by optically compensating a liquid crystal cell. <P>SOLUTION: The optical compensation film includes the alignment layer and the optical anisotropic layer containing the liquid crystal compound, and a difference between a dispersion force component γs<SP>d</SP><SB>(LC)</SB>in surface free energy of the liquid crystal compound and a dispersion force component γs<SP>d</SP><SB>(AL)</SB>in surface free energy of the alignment layer satisfies the following inequality: γs<SP>d</SP><SB>(LC)</SB>-γs<SP>d</SP><SB>(AL)</SB>≥-4.0 erg/cm2. In the liquid crystal compound, form or the like being a disk-like liquid crystal compound is preferable. The liquid crystal display device includes at least one optical compensation film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical compensation film that can easily control the retardation of an optically anisotropic layer, and a liquid crystal display device using the same.

  In the liquid crystal display device, polarizing plates are attached to both sides of the liquid crystal cell, and one or more optical compensation films are further disposed. This optical compensation film is an indispensable member for a liquid crystal display device, and it is essential to strictly control the retardation of the optical compensation film.

  Regarding the control of retardation, for example, Patent Document 1 proposes an optical compensation film having an optically anisotropic layer in which retardation is easily adjusted by controlling the orientation of a liquid crystalline compound. . Non-Patent Document 1 describes that the orientation of the rod-like liquid crystal compound on the alignment film depends on the magnitude relationship of the surface tension between the alignment film and the liquid crystal compound. Non-Patent Document 2 describes that the pretilt angle at the time of alignment of the rod-like liquid crystalline compound varies depending on the carbon chain length of the alignment film.

However, regarding the orientation of the discotic liquid crystalline compound described in Patent Document 1, the Non-Patent Documents 1 and 2 do not mention anything.
On the other hand, for a discotic liquid crystalline compound, a technique for controlling the orientation by the I / O value of the alignment film has been proposed (see Patent Document 2), but the relationship between the alignment film and the liquid crystalline compound and the liquid crystalline compound are proposed. There is no disclosure about the characteristics of.
Therefore, the relationship between the alignment film and the liquid crystalline compound is specified, or the technology that can easily control the retardation of the optical anisotropic layer in the optical compensation film according to the characteristics of the liquid crystalline compound, and the optical compensation film are used. Thus, there is a strong demand for the development of a technique capable of optically compensating the liquid crystal cell and reducing the color shift depending on the viewing angle direction and improving the contrast.

JP-A-8-50206 JP-A-7-333431 JA Applied Physics (1976) 47, 1270 Synthetic Metals (2001) 117, 267 pages

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention provides an optical compensation film and a liquid crystal cell which can regulate the relationship between the alignment film and the liquid crystalline compound, and can easily control the retardation of the optically anisotropic layer according to the characteristics of the liquid crystalline compound. It is an object of the present invention to provide a liquid crystal display device that can compensate for this and improve the contrast and reduce the color shift depending on the viewing angle direction.

Means for solving the above-mentioned problems are as follows. That is,
<1> An alignment film and an optically anisotropic layer containing a liquid crystalline compound, the dispersion force component γs ^d _(LC) in the surface free energy of the liquid crystalline compound and the dispersion force in the surface free energy of the alignment film The optical compensation film is characterized in that the difference from the component γs ^d _(AL) satisfies the following formula: γs ^d _(LC) −γs ^d _(AL) ≧ −4.0 erg / cm ² .
<2> The optical compensation film according to <1>, wherein the liquid crystal compound is a discotic liquid crystal compound.
<3> The optical compensation film according to any one of <1> and <2>, wherein the liquid crystalline compound includes at least one compound represented by the following general formula (DI).
However, Y < ₁₁ >, Y < ₁₂ >, and Y < ₁₃ > represent either a methine and a nitrogen atom each independently in general formula (DI). L ₁ , L ₂ , and L ₃ each independently represent a single bond or a divalent linking group. H ₁ , H ₂ , and H ₃ each independently represent any of the following general formula (DI-A) and the following general formula (DI-B). R ₁ , R ₂ , and R ₃ each independently represent the following general formula (DI-R).
In the general formula (DI-A), respectively the YA ₁ and YA ₂ independently represents any of methine and nitrogen atoms. XA represents an oxygen atom, a sulfur atom, methylene, or imino. * Represents a position where L _{1 to} L ₃ are bonded, and ** represents a position where R _{1 to} R ₃ are bonded.
However, the general formula (DI-B), YB ₁ and YB ₂ represent either each independently methine or nitrogen atom. XB represents an oxygen atom, a sulfur atom, methylene, or imino. * Represents a position where L _{1 to} L ₃ are bonded, and ** represents a position where R _{1 to} R ₃ are bonded.
[General formula (DI-R)]
*-(-L ₂₁ -M) n ₁ -L ₂₂ -L ₂₃ -Q ₁
However, * represents the position couple | bonded with the 5-membered ring in general formula (DI) in the said general formula (DI-R). L ₂₁ represents a single bond or a divalent linking group, and L ₂₂ represents —O—, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH. —, —SO ₂ —, —CH ₂ —, —CH═CH—, and —C≡C— are represented, and L ₂₃ represents —O—, —S—, —C (═O) —, — It represents a divalent linking group selected from the group consisting of SO ₂ —, —NH—, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. M represents a divalent linking group having at least one cyclic structure. Q ₁ each independently represents either a polymerizable group or a hydrogen atom. n ₁ represents an integer of 0-4.
<4> The optical compensation film according to any one of <1> to <3>, wherein the liquid crystal compound has an average inclination angle of 45 ° or less.
<5> The optical compensation film according to any one of <1> to <4>, wherein the alignment film contains a vinyl alcohol compound.
<6> A liquid crystal display device comprising at least one optical compensation film according to any one of <1> to <5>.

The optical compensation film of the present invention includes an alignment film and an optically anisotropic layer containing a liquid crystalline compound, and a dispersion force component in the surface free energy of the liquid crystalline compound and a dispersion force in the surface free energy of the alignment film. The retardation of the optically anisotropic layer in the optical compensation film can be easily controlled by setting the difference from the component to −4.0 erg / cm ² or more, or by using a discotic liquid crystalline compound as the liquid crystalline compound.

  By including at least one optical compensation film of the present invention, the liquid crystal display device of the present invention optically compensates the liquid crystal cell, and can improve contrast and reduce the color shift depending on the viewing angle direction.

  According to the present invention, the conventional problems can be solved, the relationship between the alignment film and the liquid crystalline compound can be defined, and the retardation control of the optically anisotropic layer can be facilitated by the characteristics of the liquid crystalline compound. An optical compensation film and a liquid crystal display device capable of optically compensating a liquid crystal cell and reducing a color shift depending on an improvement in contrast and a viewing angle direction can be provided.

  More specifically, the phase difference of the optically anisotropic layer can be controlled by paying attention to the surface free energy of the alignment film and the liquid crystal compound and adjusting the relationship between them, that is, the surface free energy difference. . Furthermore, since the liquid crystalline compound can be a discotic liquid crystalline compound, an optical compensation film can be provided that has the retardation wavelength dispersion characteristic adapted to the liquid crystal cell in the black display state, so that the black display and black state on the front surface can be provided. Can be compensated for at almost all wavelengths. And by using the said optical compensation film, the liquid crystal display device of this invention reduces the light leakage of the front and the diagonal direction at the time of black display, and the black floating of a front and a viewing angle contrast are improved remarkably. In addition, the liquid crystal display device can suppress light leakage in the front and oblique directions during black display in almost all visible light wavelength regions. Can be greatly improved.

(Optical compensation film)
The optical compensation film of the present invention includes an alignment film and an optically anisotropic layer containing a liquid crystalline compound.
The optical compensation film has, for example, at least two layers of a cellulose acylate film and an optically anisotropic layer having optical anisotropy in the plane, and between the cellulose acylate film and the optically anisotropic layer. It is preferable to have an alignment film that controls the alignment of the liquid crystalline compound in the optically anisotropic layer. Moreover, as long as the optical characteristic mentioned later is satisfy | filled, the said cellulose acylate film and an optically anisotropic layer may have 2 or more layers, respectively. In the present specification, the “cellulose acylate film” includes a cellulose acetate film.

Table with dispersion force component gamma] s ^d of the dispersion force component γs ^d _(AL) in the surface free energy of the _(LC) and the alignment layer (AL), the following formula (A) in the surface free energy of the liquid crystal compound (LC) The difference Δγs ^d to be made is −4.0 erg / cm ² or more.
[Formula (A)]
Δγs ^d = γs ^d _(LC) −γs ^d _(AL)
The Derutaganmaesu ^d is a -4.0erg / cm ² or more, preferably -1.0erg / cm ² or more, 0.0erg / cm ² or more 3.0erg / cm ² or less being more preferred.

Here, the surface free energy according to the present invention, D.K.Owens:. J.Appl.Polym.Sci, 13,1741 pure _{H 2} was measured by reference to (1969) O and methylene iodide CH _From the respective contact angles θ _H2O and θ _CH2I2 with ₂ I ₂ , the following simultaneous equations (1) and (2) are obtained. When the contact angle θ _glycerin is obtained using glycerin instead of pure water, it is obtained by the following simultaneous equations (2) and (3).
(Simultaneous equations)
_{(1): 1 + cosθ H2O} = 2√γs d (√γ H2O d / γ H2O v) + 2√γs h (√γ H2O h / γ H2O v)
_{(2): 1 + cosθ CH2I2} = 2√γs d (√γ CH2I2 d / γ CH2I2 v) + 2√γs h (√γ CH2I2 h / γ CH2I2 v)
^{_{γ H2O d = 21.8, γ H2O}} h = 51.0, γ H2O v = 72.8, γ CH2I2 d = 49.5, γ CH2I2 h = 1.3, γ CH2I2 v = 50.8
(3): 1 + cosθ _glycerin = 2√γs ^d (√γ _glycerin ^d / ^γ _glycerin ^v) + 2√γs ^h (√γ _glycerin ^h / ^γ _glycerin ^v)
γ- _glycerin ^d = 37.4, γ- _glycerin ^h = 26.0, γ- _glycerin ^v = 63.4
However, in the simultaneous equations, the dispersion force component of the gamma] s ^d is the surface free energy, the hydrogen bond component of the gamma] s ^h is the surface free energy, correspond respectively, the value represented by their sum γs v ⁽⁼ γs d ⁺ γs ^h ) is defined as surface free energy.
The contact angle was measured using a DropMaster 500 manufactured by Kyowa Interface Science Co., Ltd., after conditioning the sample for 24 hours at 25 ° C. and 60%, and then adding 10 μl of pure water and methylene iodide to the surface of the sample. It is carried out 30 seconds after dropping.

<Optically anisotropic layer>
The position where the optically anisotropic layer is formed is not particularly limited, but it is preferable to form an alignment film on the cellulose acylate film and form the alignment film on the alignment film. Also, the optical compensation film of the present invention is produced by transferring an optically anisotropic layer containing a liquid crystalline compound formed on another substrate onto a cellulose acylate film using an adhesive, an adhesive, or the like. It is also possible to do. In addition, there is no restriction | limiting in particular as said cellulose acylate film, According to the objective, it can select suitably.

The liquid crystalline compound used for forming the optically anisotropic layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a rod-like liquid crystalline compound and a discotic liquid crystalline compound (hereinafter referred to as “discotic”). And may be referred to as a “liquid crystalline compound”).
The rod-like liquid crystal compound and the discotic liquid crystal compound may be a polymer liquid crystal or a low molecular liquid crystal. In addition, the compound finally contained in the optically anisotropic layer may not exhibit liquid crystallinity. For such an embodiment, for example, a low molecular liquid crystalline compound is used for the production of the optically anisotropic layer. In such a case, in the process of forming the optically anisotropic layer, the low-molecular liquid crystalline compound is cross-linked and no longer exhibits liquid crystallinity.

-Rod-like liquid crystalline compound-
The rod-like liquid crystalline compound is not particularly limited, and examples thereof include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, and cyano-substituted compounds. Preferable examples include phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, alkenylcyclohexylbenzonitriles and the like.
The rod-like liquid crystalline compound may contain a metal complex. Further, the rod-like liquid crystalline compound may be a liquid crystal polymer that is bonded to a polymer and contains the rod-like liquid crystalline compound in a repeating unit.
As for the rod-like liquid crystal compound, for example, the quarterly chemical review volume 22 Liquid Crystal Chemistry (1994) Chapter 4, Chapter 7 and Chapter 11 of the Chemical Society of Japan, Liquid Crystal Device Handbook, JSPS 142th Committee It is described in Chapter 3 of the volume.

The birefringence of the rod-like liquid crystalline compound used in the present invention is preferably in the range of 0.001 to 0.7, for example.
The rod-like liquid crystalline compound preferably has a polymerizable group in order to fix the alignment state. As the polymerizable group, for example, an unsaturated polymerizable group or an epoxy group is preferable, an unsaturated polymerizable group is more preferable, and an ethylenically unsaturated polymerizable group is particularly preferable.

-Discotic liquid crystalline compounds-
The discotic liquid crystalline compound is not particularly limited. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985) and Physics lett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984), cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. 1794 (1985) and J. Am. Zhang et al. Am. Chem. Soc. 116, page 2655 (1994), such as azacrown and phenylacetylene macrocycles.

  The discotic liquid crystalline compound has a liquid crystallinity having a structure 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. The compounds shown are also included. Further, the discotic liquid crystalline compound is preferably a compound in which a molecule or an assembly of molecules has rotational symmetry and can impart a certain orientation.

As described above, when an optically anisotropic layer is formed from a liquid crystalline compound, the liquid crystalline compound finally contained in the optically anisotropic layer may not exhibit liquid crystallinity. For example, a low molecular weight discotic liquid crystalline compound has a group that reacts with heat or light, and the group reacts with heat or light to polymerize or crosslink to increase the molecular weight. When a layer is formed, the compound contained in the optically anisotropic layer may have lost liquid crystallinity.
Preferable examples of the discotic liquid crystalline compound include those described in JP-A-8-50206. The polymerization of discotic liquid crystalline compounds is described in, for example, JP-A-8-27284.

In order to fix the discotic liquid crystalline compound by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystalline compound. However, if the polymerizable group is directly coupled to the discotic core, it becomes difficult to maintain the orientation state in the polymerization reaction, so that a linking group is introduced between the discotic core and the polymerizable group. Is preferred.
The discotic liquid crystalline compound having such a polymerizable group is preferably a discotic liquid crystalline compound (A) represented by the following structural formula (A) and a compound represented by the following general formula (DI), A compound represented by the formula (DI) is particularly preferred.

In the general formula (DI), Y ₁₁ , Y ₁₂ , and Y ₁₃ each independently represent either methine or a nitrogen atom.
When Y ₁₁ , Y ₁₂ and Y ₁₃ are methine, they may have a substituent.
Examples of the substituent include 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, a halogen atom, and a cyano group. . Among these, 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. -12 alkoxycarbonyl group, C2-C12 acyloxy group, halogen atom, and cyano group are more preferable.

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) —, —NH—, —SO ₂ —, — It is preferably a divalent linking group selected from the group consisting of CH═CH—, —C≡C—, and combinations thereof. When these groups are groups containing a hydrogen atom, the hydrogen atom may be replaced with a substituent.
Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted with halogen, 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 an alkyl group. A carbamoyl group having 2 to 6 carbon atoms and an acylamino group having 2 to 6 carbon atoms are preferable, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferable.

The divalent linking group represented by L ₁ , L ₂ , and L ₃ may be a divalent cyclic group having at least one cyclic structure.
The divalent cyclic group is preferably a 5-membered ring, 6-membered ring, or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and particularly preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring, a monocyclic ring, or more preferably a monocyclic ring.
The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring and a naphthalene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring. The cyclic group is preferably an aromatic ring or a heterocyclic ring.

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

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 1 to 16 carbon atoms, an alkynyl group having 1 to 16 carbon atoms, and the number of carbon atoms. 1-16 halogen-substituted alkyl groups, alkoxy groups having 1-16 carbon atoms, acyl groups having 2-16 carbon atoms, alkylthio groups having 1-16 carbon atoms, acyloxy groups having 2-16 carbon atoms, carbon Examples thereof include an alkoxycarbonyl group having 2 to 16 atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 16 carbon atoms, and an acylamino group having 2 to 16 carbon atoms.

Examples of L ₁ , L ₂ , and L ₃ include a single bond, * —O—CO—, * —CO—O—, * —CH═CH—, * —C≡C—, * —M—, * -O-CO-M-, * -CO-OM-, * -CH = CH-M-, * -C≡C-M-, * -M-O-CO-, * -M-CO- O-, * -M-CH = CH-, * -M-C≡C- are preferred. In particular, a single bond, * —CH═CH—, * —C≡C—, * —CH═CH—M—, * —C≡C—M— is preferable, and a single bond is particularly preferable. In addition, said * represents the position couple | bonded with the 6-membered ring containing Y < ₁₁ >, Y < ₁₂ > and Y < ₁₃ > in the said general formula (I), and said M represents a bivalent cyclic group.

In the general formula (DI), H ₁ , H ₂ , and H ₃ each independently represent any of the following general formula (DI-A) and the following general formula (DI-B).
In the general formula (DI-A), respectively the YA ₁ and YA ₂ independently represents any of methine and nitrogen atoms. XA represents an oxygen atom, a sulfur atom, methylene, or imino. * Represents a position where L _{1 to} L ₃ are bonded, and ** represents a position where R _{1 to} R ₃ are bonded.
However, the general formula (DI-B), YB ₁ and YB ₂ represent either each independently methine or nitrogen atom. XB represents an oxygen atom, a sulfur atom, methylene, or imino. * Represents a position where L _{1 to} L ₃ are bonded, and ** represents a position where R _{1 to} R ₃ are bonded.

In the general formula (DI), R ₁ , R ₂ , and R ₃ each independently represents the following general formula (DI-R).
[General formula (DI-R)]
*-(-L ₂₁ -M) n ₁ -L ₂₂ -L ₂₃ -Q ₁
However, * represents the position couple | bonded with the 5-membered ring in the said general formula (DI) in the said general formula (DI-R).
In the general formula (DI-R), L ₂₁ represents either a single bond or a divalent linking group. When L ₂₁ is a divalent linking group, —O—, —S—, —C (═O) —, —NH—, —SO ₂ —, —CH═CH—, —C≡C—, And a divalent linking group selected from the group consisting of these and combinations thereof. When these groups contain a hydrogen atom, the hydrogen atom may be replaced with a substituent.
Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted with halogen, 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 an alkyl group. A carbamoyl group having 2 to 6 carbon atoms and an acylamino group having 2 to 6 carbon atoms are preferable, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferable.

L ₂₁ is preferably a single bond, —O—CO—, —CO—O—, —CH═CH—, —C≡C—, and more preferably a single bond.

The divalent linking group represented by L ₂₁ may be a divalent cyclic group having at least one cyclic structure.
The divalent cyclic group is preferably a 5-membered ring, 6-membered ring, or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and particularly preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring, a monocyclic ring, or more preferably a monocyclic ring.
The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.

Among the divalent cyclic group represented by _{L 21,} as the cyclic group having the benzene ring, for example, 1,4-phenylene, 1,3-phenylene is preferred. Examples of the cyclic group having a naphthalene ring include naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-2,5-diyl, naphthalene-2,6- Diylnaphthalene-2,7-diyl is preferred. As the cyclic group having a cyclohexane ring, for example, 1,4-cyclohexylene is preferable. As the cyclic group having a pyridine ring, for example, pyridine-2,5-diyl is preferable. As the cyclic group having a pyrimidine ring, for example, pyrimidine-2,5-diyl is preferable. As the divalent cyclic group, 1,4-phenylene, 1,3-phenylene, and naphthalene-2,6-diyl are particularly preferable.

The divalent cyclic group represented by L ₂₁ may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), cyano group, nitro group, alkyl group having 1 to 16 carbon atoms, and alkenyl group having 1 to 16 carbon atoms. , An alkynyl group having 1 to 16 carbon atoms, a halogen-substituted alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, and an alkyl group having 1 to 16 carbon atoms Examples include an alkylthio group, an acyloxy group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 16 carbon atoms, and an acylamino group having 2 to 16 carbon atoms. It is done. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and a halogen-substituted alkyl group having 1 to 6 carbon atoms are preferable, and a halogen atom, an alkyl group having 1 to 4 carbon atoms, and the number of carbon atoms A halogen-substituted alkyl group having 1 to 4 halogen atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are particularly preferable.

N < ₁ > represents the integer of 0-4 in the said general formula (DI-R). N ₁ is preferably an integer of ₁ to 3, and any one of 1 and 2 is particularly preferable.

In the general formula (DI-R), L ₂₂ represents —O—, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, It represents any of —CH ₂ —, —CH═CH—, and —C≡C—, —O—, —O—CO—, —CO—O—, —O—CO—O—, —CH _2. —, —CH═CH—, —C≡C— are preferred, and —O—, —O—CO—, —O—CO—O—, —CH ₂ — are more preferred. When these groups are groups containing a hydrogen atom, the hydrogen atom may be replaced with a substituent.
Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted with halogen, 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 an alkyl group. A carbamoyl group having 2 to 6 carbon atoms and an acylamino group having 2 to 6 carbon atoms are preferable, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferable.

In the general formula (DI-R), L ₂₃ represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH—, — It represents a divalent linking group selected from the group consisting of C≡C— and combinations thereof. Here, the hydrogen atoms of —NH—, —CH ₂ —, and —CH═CH— may be replaced with other substituents.
Examples of the other substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, a halogen-substituted alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , 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 to 2 carbon atoms 6 alkyl-substituted carbamoyl groups, and acylamino groups having 2 to 6 carbon atoms. Among these, a halogen atom and an alkyl group having 1 to 6 carbon atoms are particularly preferable. By being substituted by these substituents, when preparing a liquid crystalline composition from the liquid crystalline compound of the present invention, solubility in a solvent to be used can be improved.

L ₂₃ is preferably composed of a combination of —O—, —C (═O) —, —CH ₂ —, —CH═CH—, and —C≡C—. The L ₂₃ preferably contains 1 to 20 carbon atoms, and particularly preferably 2 to 14 carbon atoms. Furthermore, L ₂₃ preferably contains 1 to 16 —CH ₂ —, and particularly preferably 2 to 12 —CH ₂ —.

In the general formula (DI), Q ₁ each independently represents either a polymerizable group or a hydrogen atom. Q ₁ is preferably a polymerizable group from the viewpoint of preventing the phase difference from being changed by heat in the liquid crystal compound of the present invention. Here, the polymerization reaction is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. Therefore, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Such a polymerizable group is not particularly limited, but examples of the polymerizable group capable of addition polymerization reaction include the following groups.

The polymerizable group is particularly preferably a functional group capable of a condensation polymerization reaction, and as such a polymerizable group, for example, either a polymerizable ethylenically unsaturated group or a ring-opening polymerizable group is preferable.
Examples of the polymerizable ethylenically unsaturated group include groups represented by 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. R is preferably a hydrogen atom or a methyl group.
Among the groups represented by the above formulas (M-1) to (M-6), any one of the groups represented by the formula (M-1) and the formula (M-2) is preferable. ) Is particularly preferred.

  As the ring-opening polymerizable group, for example, a cyclic ether group is preferable, among which an epoxy group or an oxetanyl group is more preferable, and an epoxy group is particularly preferable.

As the discotic liquid crystalline compound, a compound represented by the following general formula (DII) is also particularly preferable.
However, Y < ₃₁ >, Y < ₃₂ >, and Y < ₃₃ > represent the same meaning as Y < ₁₁ >, Y < ₁₂ >, and Y < ₁₃ > in the said general formula (DI) in the said general formula (DII).

In the general formula (DII), R ₃₁ , R ₃₂ , and R ₃₃ are each independently represented by the following general formula (DII-R).
In the general formula _{(DII-R), A 31} and _{A 32} each independently represents any of methine and nitrogen atoms. Examples A ₃₁ and A ₃₂ Preferably, at least one is a nitrogen atom, and particularly preferably both are nitrogen atoms. X ₃ represents any of an oxygen atom, a sulfur atom, methylene, and imino, and is particularly preferably an oxygen atom. M represents a divalent cyclic group.

In the general formula (DII-R), the divalent cyclic group represented by M is preferably a divalent linking group having a 6-membered cyclic structure. The ring contained in the divalent cyclic group may be a condensed ring, a monocyclic ring, or more preferably a monocyclic ring.
The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.

  Among the divalent cyclic groups represented by M, as the cyclic group having a benzene ring, for example, 1,4-phenylene and 1,3-phenylene are preferable. Examples of the cyclic group having a naphthalene ring include naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-2,5-diyl, naphthalene-2,6- Diylnaphthalene-2,7-diyl is preferred. As the cyclic group having a cyclohexane ring, for example, 1,4-cyclohexylene is preferable. As the cyclic group having a pyridine ring, for example, pyridine-2,5-diyl is preferable. As the cyclic group having a pyrimidine ring, for example, pyrimidine-2,5-diyl is preferable. As the divalent cyclic group, 1,4-phenylene, 1,3-phenylene and naphthalene-2,6-diyl are particularly preferable.

  The divalent cyclic group represented by M may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, nitro group, alkyl group having 1 to 16 carbon atoms, alkenyl group having 1 to 16 carbon atoms, Alkynyl group having 1 to 16 carbon atoms, halogen-substituted alkyl group having 1 to 16 carbon atoms, alkoxy group having 1 to 16 carbon atoms, acyl group having 2 to 16 carbon atoms, alkylthio having 1 to 16 carbon atoms Group, an acyloxy group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 16 carbon atoms, and an acylamino group having 2 to 16 carbon atoms. . Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and a halogen-substituted alkyl group having 1 to 6 carbon atoms are preferable, and a halogen atom, an alkyl group having 1 to 4 carbon atoms, and the number of carbon atoms 1-4 halogen-substituted alkyl groups are more preferable, and halogen atoms, alkyl groups having 1 to 3 carbon atoms, and trifluoromethyl groups are particularly preferable.

In the general formula (DII-R), n ₃ represents an integer of 1 to 3, and either 1 or 2 is preferable.
In the general formula (DII-R), L ₃₁ , L ₃₂ and Q ₃ represent the same meaning as L ₂₂ , L ₂₃ and Q _{1 in the} general formula (DI-R), respectively.

Although there is no restriction | limiting in particular as a compound represented by either the said general formula (DI) and general formula (DII), For example, the compound shown below is mentioned.

  The liquid crystal compound of the present invention preferably exhibits a liquid crystal phase exhibiting good monodomain properties. When the monodomain property is poor, the resulting structure may be a polydomain, an orientation defect may occur at the boundary between domains, and light may be scattered. If good monodomain properties are exhibited, the retardation plate tends to have a high light transmittance.

As the liquid crystal phase in which the liquid crystalline compound expressed, for example, columnar phase, discotic nematic phase (N _D phase) and the like. Of these liquid crystal phases, a discotic nematic phase having a good monodomain property (N _D phase) are particularly preferred.

  The liquid crystalline compound preferably exhibits a liquid crystal phase in a range of 20 to 300 ° C, more preferably in a range of 40 to 280 ° C, and particularly preferably in a range of 60 to 250 ° C. Here, the expression of the liquid crystal phase in the range of 20 ° C. to 300 ° C. means that the liquid crystal temperature range is around 20 ° C. (specifically, for example, 10 ° C. to 22 ° C.) or about 300 ° C. (specifically. For example, 298 degreeC-310 degreeC) is also included. The same applies to the case where the liquid crystal phase is expressed in the range of 40 ° C. to 280 ° C. and the case where the liquid crystal phase is expressed in the range of 60 ° C. to 250 ° C.

In the present invention, in the optically anisotropic layer, the molecules of the rod-like liquid crystalline compound or the discotic liquid crystalline compound are fixed in an aligned state. The molecular symmetry axis of these liquid crystalline compounds and the orientation average direction at the interface on the cellulose acylate film side have an intersecting angle with the slow axis in the plane of the cellulose acylate film of approximately 0 degrees or approximately 45 degrees. .
Here, “substantially” means an angle in a range of ± 5 °, and the angle is preferably −3 to + 3 ° in the former case and 42 to 48 ° in the latter case, and is −2 to + 2 ° and 43 to 45 ° respectively. 47 ° is more preferable. The average direction of the molecular symmetry axis of the liquid crystalline compound in the optically anisotropic layer is −2 to + 2 ° and 43 ° to 47 with respect to the longitudinal direction of the support (that is, the fast axis direction of the support), respectively. It is preferable to be °.
In the present specification, “0 °”, “45 °”, “parallel” or “orthogonal” means that the angle is within a range of strictly less than ± 5 °. The error from the exact angle is preferably less than 4 °, more preferably less than 3 °. Regarding the angle, “+” means the clockwise direction, and “−” means the counterclockwise direction. “Slow axis” means the direction in which the refractive index is maximum. “Visible light region” means 380 nm to 780 nm. Further, the measurement wavelength of the refractive index is a value at λ = 550 nm in the visible light region unless otherwise specified.

  In the present specification, the “molecular symmetry axis” means a symmetry axis when the molecule has a rotational symmetry axis, but does not require that the molecule is rotationally symmetric in a strict sense. In general, the molecular symmetry axis of the discotic liquid crystalline compound coincides with the axis perpendicular to the disc surface passing through the center of the disc surface, and the rod-like liquid crystalline compound coincides with the long axis of the molecule.

The orientation average direction of the molecular symmetry axis in the liquid crystalline compound can be generally adjusted by selecting the material of the liquid crystalline compound or the alignment film or by selecting the rubbing treatment method.
In the present invention, for example, when an alignment film for forming an optically anisotropic layer is produced by rubbing, the liquid crystallinity is obtained by rubbing in a direction parallel to or 45 ° to the slow axis of the cellulose acylate film. An optically anisotropic layer in which the orientation average direction of the molecular symmetry axis of the compound at least at the cellulose acylate film interface is parallel (0 °) or 45 ° with respect to the slow axis of the cellulose acylate film is formed. it can.
The optical compensation film of the present invention can be continuously produced by using, for example, a long cellulose acylate film having a slow axis parallel to the longitudinal direction. More specifically, 1) an alignment film is formed by continuously applying a coating liquid for forming an alignment film on the surface of a long cellulose acylate film, and 2) the surface of the alignment film is continuously elongated. 3) A coating liquid for forming an optically anisotropic layer containing a liquid crystalline compound is continuously applied onto the prepared alignment film by rubbing in a direction parallel to the direction or 45 °, and molecules of the liquid crystalline compound Is oriented and fixed in that state, whereby an optically anisotropic layer can be produced, and a long optical compensation film can be produced continuously. The optical compensation film produced in the long shape is cut into a desired shape before being incorporated into the liquid crystal display device.

Further, with respect to the orientation average direction of the molecular symmetry axis on the surface side (air side) of the liquid crystalline compound, the orientation average direction of the molecular symmetry axis of the liquid crystalline compound on the air interface side is relative to the slow axis of the cellulose acylate film. Are preferably about 0 ° and about 45 °, more preferably −3 to + 3 ° in the former case, more preferably 42 to 48 ° in the latter case, −2 to + 2 ° and 43 to 47 °, respectively. Is particularly preferred. The orientation average direction of the molecular symmetry axis of the liquid crystal compound is selected according to the drive mode of the target liquid crystal display device. In general, the former is preferably 0 ° in the TN mode and 45 ° is preferred in the OCB mode, but the liquid crystal driving mode is not particularly limited in the present invention.
In general, the orientation average direction of the molecular symmetry axis in the liquid crystal compound on the air interface side can be adjusted by selecting the liquid crystal compound or the type of additive used together with the liquid crystal compound.
Examples of the additive used together with the liquid crystal compound include a plasticizer, a surfactant, a polymerizable monomer, and a polymerizable polymer. The degree to which the orientation direction of the molecular symmetry axis is changed can be adjusted by selecting the liquid crystalline compound and the additive as described above. In particular, the surfactant is preferably compatible with the above-described surface tension control of the coating solution.

The plasticizer, the surfactant, and the polymerizable monomer used together with the liquid crystal compound have compatibility with the discotic liquid crystal compound and can change the tilt angle of the discotic liquid crystal compound. It is preferable not to inhibit the orientation.
As such a polymerizable monomer, for example, a compound having at least one of a vinyl group, a vinyloxy group, an acryloyl group, and a methacryloyl group is preferable.
The addition amount of the compound is usually 1 to 50% by mass and preferably 5 to 30% by mass with respect to the liquid crystal compound. In addition, when a monomer having 4 or more polymerizable reactive functional groups is mixed and used, the adhesion between the alignment film and the optically anisotropic layer can be improved.

When a discotic liquid crystalline compound is used as the liquid crystalline compound, it is preferable to use a polymer that has a certain degree of compatibility with the discotic liquid crystalline compound and can change the tilt angle of the discotic liquid crystalline compound. .
Examples of such polymers include cellulose esters. Examples of the cellulose ester include cellulose acetate, cellulose acetate propionate, hydroxypropyl cellulose, and cellulose acetate butyrate.
The amount of the polymer added is preferably in the range of 0.1 to 10% by mass with respect to the discotic liquid crystalline compound so as not to inhibit the orientation of the discotic liquid crystalline compound. More preferably in the range of mass%, particularly preferably in the range of 0.1-5 mass%.
The discotic nematic liquid crystal phase-solid phase transition temperature of the discotic liquid crystalline compound is preferably 70 to 300 ° C, more preferably 70 to 170 ° C.

In the present invention, the optically anisotropic layer has at least in-plane optical anisotropy. The in-plane retardation (Re) of the optically anisotropic layer is preferably 3 to 300 nm, more preferably 5 to 200 nm, and particularly preferably 10 to 100 nm.
The retardation (Rth) in the thickness direction of the optically anisotropic layer is preferably 20 to 400 nm, and more preferably 50 to 200 nm.
The thickness of the optically anisotropic layer is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and particularly preferably 1 to 10 μm.

Here, the in-plane retardation (Re) can be measured in KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) by making light having a wavelength λ nm incident in the normal direction of the film. The retardation in the thickness direction (Rth) is as follows: 1) In-plane retardation (Re), 2) In-plane slow axis determined by KOBRA 21ADH is the tilt axis (rotation axis). A retardation value measured by making light of wavelength λ nm incident from a direction tilted by + 40 ° with respect to the direction, and 3) with respect to the film normal direction, with the in-plane slow axis as the tilt axis (rotation axis) Based on the retardation value measured by making light of wavelength λ nm incident from a direction inclined by 40 °, the assumed value of the retardation value and average refractive index measured in three directions, and the input film thickness value Calculated by KOBRA 21ADH.
Here, as the assumed value of the average refractive index, values in polymer handbooks (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. About the thing whose value of the said average refractive index is not known, it can measure with an Abbe refractometer.
The average refractive index values of the main optical films are cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), polystyrene (1. 59). The KOBRA 21ADH calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

FIG. 1 shows a simplified schematic diagram of an example of a cross section of the optically anisotropic layer of the present invention.
The optical anisotropic layer 23 is provided on the alignment film 22 formed on the support 21. The average tilt angle (hereinafter also referred to as “tilt angle” or “pretilt angle”) of the discotic liquid crystal compounds 23a, 23b, and 23c constituting the optical anisotropic layer 23 is the bottom surface of the optical anisotropic layer. As the distance in the depth (thickness) direction increases, the layer as a whole increases in order. In FIG. 1, N represents the normal line of the transparent support. Since the discotic liquid crystalline compound is a flat molecule, the molecule has only one plane, that is, a disc surface.

  The average inclination angle is preferably 45 ° or less, and more preferably 30 to 45 °. The minimum value of the tilt angle when determining the average tilt angle is preferably in the range of 0 to 85 °, and particularly preferably in the range of 5 to 40 °. Moreover, it is preferable that the maximum value of the said inclination angle exists in the range of 5-90 degrees, and it is especially preferable that it exists in 30-85 degrees. Furthermore, the difference between the minimum value and the maximum value of the average inclination angle is preferably in the range of 5 to 70 °, and more preferably in the range of 10 to 60 °.

In an optically anisotropic layer in which a discotic liquid crystalline compound or a rod-shaped liquid crystalline compound is aligned, a tilt angle on one surface of the optically anisotropic layer (a physical target axis in the discotic liquid crystalline compound or the rod-shaped liquid crystalline compound) Is the tilt angle.) It is difficult to directly and accurately measure θ1 and the tilt angle θ2 of the other surface. Therefore, in this specification, θ1 and θ2 are calculated by the following method. Although this method does not accurately represent the actual orientation state of the present invention, it is effective as a means for expressing the relative relationship between some optical properties of the optical film.
In this method, the following two points are assumed and the tilt angle at the two interfaces of the optically anisotropic layer is assumed for easy calculation.
1. The optically anisotropic layer is assumed to be a multilayer body composed of layers containing a discotic compound or a rod-like compound. Further, the minimum unit layer (the tilt angle of the discotic liquid crystalline compound or the rod-shaped liquid crystalline compound is assumed to be uniform in the layer) is assumed to be optically uniaxial.
2. It is assumed that the tilt angle of each layer changes monotonically with a linear function along the thickness direction of the optically anisotropic layer.
The specific calculation method is as follows.
(1) In a plane in which the tilt angle of each layer changes monotonically with a linear function along the thickness direction of the optically anisotropic layer, the incident angle of the measurement light to the optically anisotropic layer is changed, and three or more The retardation value is measured at the measurement angle. In order to simplify the measurement and calculation, it is preferable to measure the retardation value at three measurement angles of −40 °, 0 °, and + 40 °, with the normal direction to the optically anisotropic layer being 0 °. . Such measurement is performed by, for example, KOBRA-21ADH, KOBRA-WR (manufactured by Oji Scientific Instruments), transmission type ellipsometer AEP-100 (manufactured by Shimadzu Corporation), M150, M520 (JASCO Corporation) )), ABR10A (manufactured by UNIOPT Co., Ltd.) and the like.
(2) The refractive index of ordinary light in each layer is no, the refractive index of extraordinary light is ne (no and ne are the same values in all layers), and the thickness of the entire multilayer body is d. Further, based on the assumption that the tilt direction in each layer and the uniaxial optical axis direction of the layer coincide with each other, the calculation of the angular dependence of the retardation value of the optically anisotropic layer agrees with the measured value. Fitting is performed using the tilt angle θ1 on one surface of the anisotropic layer and the tilt angle θ2 on the other surface as variables, and θ1 and θ2 are calculated.
Here, known values such as literature values and catalog values can be used for no and ne. If the value is unknown, it can also be measured using an Abbe refractometer. The thickness of the optically anisotropic layer can be measured by an optical interference film thickness meter, a cross-sectional photograph of a scanning electron microscope, or the like.

  For example, in FIG. 1, the inclination angle (θa in the illustrated example) of the discotic structural unit on the support 21 side substantially corresponds to the minimum value, and the discotic structural unit on the side farthest from the support 21. The inclination angle (θc in the illustrated example) substantially corresponds to the maximum value, and the inclination angle (θb in the illustrated example) of the discotic structure unit between the two corresponds to the average inclination angle. Here, the inclination angle of the discotic structural unit is the inclination of the discotic structure disk surface with respect to the transparent support. In FIG. 1, the inclination angle of the discotic disk surface normal to the transparent support normal is equal.

<Alignment film>
The alignment film of the present invention is provided, for example, on a transparent support made of the cellulose acylate film. The alignment film has a function of defining an alignment direction of a liquid crystal compound such as the discotic liquid crystal compound.
The alignment film is a polymer layer that has been subjected to an alignment treatment such as a rubbing treatment, and the polymer constituting the polymer layer is not particularly limited. For example, polyvinyl alcohol is preferable.
Examples of the polyvinyl alcohol include those in which at least one hydroxyl group is substituted with a group having vinyl, oxiranyl, or aziridinyl. These are generally the polymer chain (carbon atom) of the polyvinyl alcohol, an ether bond (—O—), a urethane bond (—OCONH—), an acetal bond ((—O—) ₂ CH—) as a linking group, Alternatively, it is preferably bonded indirectly via an ester bond (—OCO—), and more specifically, the group having vinyl, oxiranyl, or aziridinyl is bonded to polyvinyl alcohol together with the bonding group. It is preferable.

Although there is no restriction | limiting in particular as said polyvinyl alcohol, For example, the polymer represented by following formula (I) is mentioned.

However, in the formula (I), L ¹¹ represents an ether bond, a urethane bond, an acetal bond, and any one of an ester bond, R ¹¹ represents any of an alkylene group and an alkylene group, L ¹² is R It represents a linking group connecting the ¹¹ and ^{Q 11, Q 11} represents any of vinyl, oxiranyl, and aziridinyl. Under the condition of x1 + y1 + z1 = 100, x1 is 10 to 99.9 mol%, y1 is 0.01 to 80 mol%, and z1 is 0 to 70 mol%. k and h each represents an integer of 0 or 1.

In the general formula (I), as R ¹¹ , for example, an alkylene group having 1 to 24 carbon atoms and at least one non-adjacent CH ₂ group is —O—, —CO—, —NH—, —NR ⁷ —. (R ⁷ represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 15 carbon atoms), —S—, —SO ₂ —, a carbon atom substituted with arylene having 6 to 15 carbon atoms An alkylene group of 3 to 24, alkyl, aryl, alkoxy, aryloxy, alkylthio, arylthio, halogen, alkylcarbonyl, arylcarbonyl, alkylsulfonyl, arylsulfonyl, hydroxyl, mercapto, amino, alkylcarbonyloxy, arylcarbonyloxy, alkylsulfonyl Oxy, arylsulfonyloxy, alkylcarbonylthio, aryl And an alkylene group substituted with sulfocarbonylthio, alkylsulfonylthio, arylsulfonylthio, alkylcarbonylamino, arylcarbonylamino, alkylsulfonylamino, arylsulfonylamino, carboxy, and sulfo.

Examples of R ¹¹ include —R ² —, —R ³ — (O—R ⁴ ) _t —OR ⁵ —, —R ³ —CO—R ⁶ —, —R ³ —NH—R ⁶ —, —R ^{3. -NR 7 -R 6 -, - R} 3 -S-R 6 -, - R 3 -SO 2 -R 6 -, and ^{-R 3 -A 2 -R 6 - (} R 2, R 3, R 4, R ⁵ and R ⁶ each represent an alkylene group having 1 to 24 carbon atoms, R ⁷ represents any of an alkyl group having 1 to 12 carbon atoms and an aryl group having 6 to 15 carbon atoms, and A ² represents an arylene group having 6 to 24 carbon atoms, and t represents an integer of 0 to 4).
Further, R ¹¹ represents —R ² — and —R ³ — (O—CH ₂ CH ₂ ) _t — (wherein R ² and R ³ each represent an alkylene group having 1 to 12 carbon atoms, and t Represents an integer of 0 to 2). Among these, an alkylene group having 1 to 12 carbon atoms is preferable.

  The alkylene group may have a substituent. Examples of the substituent include an alkyl group having 1 to 24 carbon atoms, an aryl group having 6 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, and an aryloxy group having 6 to 24 carbon atoms, An alkylthio group having 1 to 24 carbon atoms, an arylthio group having 6 to 24 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom), an alkylcarbonyl group having 2 to 24 carbon atoms, and 7 to 24 carbon atoms. Arylcarbonyl group, alkylsulfonyl group having 1 to 24 carbon atoms, arylsulfonyl group having 6 to 24 carbon atoms, hydroxyl group, mercapto group, amino group, alkylcarbonyloxy group having 2 to 24 carbon atoms, carbon atom An arylcarbonyloxy group having 7 to 24 carbon atoms, an alkylsulfonyloxy having 1 to 24 carbon atoms, an arylsulfo having 6 to 24 carbon atoms Ruoxy group, alkylcarbonylthio group having 2 to 24 carbon atoms, arylcarbonylthio group having 7 to 24 carbon atoms, alkylsulfonylthio group having 1 to 24 carbon atoms, arylsulfonylthio group having 6 to 24 carbon atoms Alkylcarbonylamino group having 2 to 24 carbon atoms, arylcarbonylamino group having 7 to 24 carbon atoms, alkylsulfonylamino group having 1 to 24 carbon atoms, arylsulfonylamino group having 6 to 24 carbon atoms, carboxy Group and sulfo group.

Preferred examples of the substituent for the alkylene group include alkyl groups having 1 to 24 carbon atoms (particularly 1 to 12 carbon atoms), aryl groups having 6 to 24 carbon atoms (particularly 6 to 14 carbon atoms), and carbon atoms. Examples thereof include alkoxyalkyl groups having 2 to 24 carbon atoms (particularly 2 to 12 carbon atoms).
Examples of the alkyl group include methyl, ethyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, i-propyl, and i-propyl. Examples include butyl, sec-butyl, t-amyl, 2-ethylhexyl and the like.
Examples of the alkyl group substituted with 1 to 4 alkoxy groups include 2-methoxyethyl, 2- (2-methoxyethoxy) ethyl, 2- [2- (2-methoxyethoxy) ethoxy] ethyl, 2 -N-butoxyethyl, 2-ethoxyethyl, 2- (2-ethoxyethoxy) ethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-n-propyloxypropyl, 2-methylbutyloxymethyl and the like can be mentioned.
Examples of the aryl group include phenyl, 2-tolyl, 3-tolyl, 4-tolyl, 2-anisyl, 3-anisyl, 4-anisyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 1-naphthyl, 2-naphthyl and the like can be mentioned. The aryl group may be a heterocyclic group, and examples of the heterocyclic group include pyridyl, pyrimidyl, thiazolyl and oxazolyl.

In the formula (I), L ¹² is, for example, —O—, —S—, —CO—, —O—CO—, —CO—O—, —O—CO—O—, —CO—O. -CO-, -NRCO-, -CONR-, -NR-, -NRCONR-, -NRCO-O-, -OCONR- (wherein R represents a hydrogen atom or a lower alkyl group) are preferred.
In the formula (I),-(L ¹² ) _h
The -Q ^12, eg, vinyl, vinyloxy, acryloyl, methacryloyl, crotonoyl, acryloyloxy, methacryloyloxy, crotonoyloxy oxy, vinyl phenoxy, vinyl benzoyloxy, styryl, 1,2-epoxy ethyl, 1,2-epoxy-propyl 2,3-epoxypropyl, 1,2-iminoethyl, 1,2-iminopropyl, 2,3-iminopropyl, and the like are preferable.
Furthermore, the-(L ¹² ) _h
The -Q ^12, vinyl, vinyloxy, acryloyl, methacryloyl, acryloyloxy, methacryloyloxy, crotonoyloxy oxy, vinyl benzoyloxy, 1,2-epoxy ethyl, 1,2-epoxypropyl, 2,3-epoxypropyl, 1 , 2-iminoethyl, 1,2-iminopropyl and 2,3-iminopropyl are also preferred. Among these, acryloyl, methacryloyl, acryloyloxy, and methacryloyloxy are particularly preferable.

1-24 pieces are preferable and, as for the carbon atom number of the said alkyl group and an alkoxy group, 1-12 pieces are especially preferable.
Examples of the alkyl group include unsubstituted alkyl groups (for example, methyl, ethyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n- Dodecyl, i-propyl, i-butyl, sec-butyl, t-amyl, 2-ethylhexyl and the like; alkyl groups substituted with 1-4 alkoxy (for example, 2-methoxyethyl, 2- (2-methoxyethoxy) ) Ethyl, 2- [2- (2-methoxyethoxy) ethoxy] ethyl, 2-n-butoxyethyl, 2-ethoxyethyl, 2- (2-ethoxyethoxy) ethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-n-propyloxypropyl, 3-benzyloxypropyl, 2-methylbutyloxymethyl and the like); an aralkyl group (for example, 2- Phenylethyl and 2- (4-n-butyloxyphenyl) ethyl); vinylalkyl groups (eg, vinylmethyl, 2-vinylethyl, 5-vinylpentyl, 6-vinylhexyl, 7-vinylheptyl, 8-vinyloctyl, etc.) A vinyloxyalkyl group (for example, 2-vinyloxyethyl, 5-vinyloxypentyl, 6-vinyloxyhexyl, 7-vinyloxyheptyl, 8-vinyloxyoctyl, etc.); an oxiranylalkyl group (for example, 3, 4-epoxybutyl, 4,5-epoxypentyl, 5,6-epoxyhexyl, 6,7-epoxyheptyl, 7,8-epoxyoctyl, 6,7-epoxyoctyl, etc.); acryloyloxyalkyl group (for example, 2 -Acryloyloxyethyl, 3-acryloyloxypropyl, 4- Acryloyloxybutyl, 5-acryloyloxypentyl, 6-acryloyloxyhexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl, etc.); methacryloyloxyalkyl groups (for example, 2-methacryloyloxyethyl, 3-methacryloyloxypropyl, 4-methacryloyloxybutyl, 5-methacryloyloxypentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl, 8-methacryloyloxyoctyl and the like; crotonoyloxyalkyl groups (for example, 2-crotonoyloxyethyl, 3-croto Noyloxypropyl, 4-crotonoyloxybutyl, 5-crotonoyloxypentyl, 6-crotonoyloxyhexyl, 7-crotonoyloxyheptyl and 8 -Crotonoyloxyoctyl etc.).

In the formula (I), as x1 + y1 + z1, x1 is preferably 50 to 99.9 mol% under the condition of x1 + y1 + z1 = 100. y1 is preferably from 0.01 to 50 mol%, more preferably from 0.01 to 20 mol%, still more preferably from 0.01 to 10 mol%, particularly preferably from 0.01 to 5 mol%. z1 is preferably 0.01 to 50 mol%.
Here, by increasing the ratio of x1, it becomes easy to increase the value of the hydrogen bond component γs ^h _(AL) of the surface free energy in the alignment film, thereby easily decreasing the value of γs ^d _(AL). it can. Therefore, Δγs ^d can be adjusted by the ratio of x1.

-Retardation raising agent-
In the optical compensation film of the present invention, it is preferable to use a retardation increasing agent in order to develop a retardation value.
Here, in this specification, “retardation increasing agent” means that the in-plane retardation (Re) 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 in-plane retardation (Re) value (unstretched state) measured at a wavelength of 550 nm of a cellulose acylate film produced in exactly the same manner.
The increase in the in-plane retardation (Re) 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 amount of the retardation increasing agent used is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and further 0.2 to 5 parts by mass with respect to 100 parts by mass of the polymer. 0.5 to 2 parts by mass is preferable. In addition, the said retardation raising agent may be used individually by 1 type, and may use 2 or more types together.
The retardation increasing agent preferably has maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

In the optical compensation film of the present invention, the difference between the dispersion force component in the surface free energy of the liquid crystalline compound and the dispersion force component in the surface free energy of the alignment film is set to −4.0 erg / cm ² or more. By using a discotic liquid crystalline compound, it is possible to easily control the retardation of the optically anisotropic layer in the optical compensation film, so that it can be suitably used for a polarizing plate in a liquid crystal display device. It can use suitably for an apparatus.

(Liquid crystal display device)
<Polarizing plate>
In the present invention, a polarizing plate comprising a polarizing film and a pair of protective films sandwiching the polarizing film can be used. For example, a polarizing plate obtained by dyeing a polarizing film made of a polyvinyl alcohol film or the like with iodine, stretching, and laminating both surfaces with a protective film can be used. The polarizing plate is disposed outside the liquid crystal cell. It is preferable that a pair of polarizing plates each including a polarizing film and a pair of protective films sandwiching the polarizing film are disposed with the liquid crystal cell interposed therebetween.
At least one of the pair of protective films sandwiching the polarizing film is the optical compensation film of the present invention. That is, the liquid crystal display device of the present invention includes at least one optical compensation film of the present invention.

  Here, in this specification, unless otherwise specified, the “polarizing plate” is cut into a size to be incorporated into a long polarizing plate and a liquid crystal device (in this specification, “cutting” includes “ It includes “punching” and “cutting out.”) It is used to include both polarizing plates. Further, in this specification, “polarizing film” and “polarizing plate” are distinguished from each other, and “polarizing plate” is a laminate having a protective film for protecting the polarizing film on at least one surface of the “polarizing film”. means.

-Adhesive-
The adhesive between the polarizing film and the protective film is not particularly limited. For example, a modified polyvinyl alcohol such as an acetoacetyl group, a sulfonic acid group, a carboxyl group, or an oxyalkylene group (hereinafter simply referred to as “PVA”). PVA-based resin, boron compound aqueous solution, and the like, which may contain a PVA-based resin, among which PVA-based resin is preferable.
The thickness of the layer made of the adhesive is preferably 0.01 to 10 μm, particularly preferably 0.05 to 5 μm after drying.

-Manufacturing method of polarizing film and protective film-
The polarizing plate that can be used in the present invention includes at least a drying step for reducing the volatile content by contracting the film for polarizing film after stretching, and after bonding a protective film on at least one side after drying, It is preferable to include a post-heating step for heating.
In the aspect in which the protective film also serves as a support for the optically anisotropic layer functioning as a transparent film, heating is performed after bonding the protective film on one side and the support having the optically anisotropic layer on the opposite side. Is preferred.
As a specific attaching method, a method of attaching a protective film to the polarizing film using an adhesive while holding both ends during the film drying process, and then cutting both ends, and a polarizing film from the both ends holding part after drying Examples include a method of releasing a protective film, cutting both ends of the film, and then attaching a protective film.
The cutting method is not particularly limited, and a known method can be appropriately selected and used. Examples of the cutting method include a method of cutting with a cutter such as a blade, a method of using a laser, and the like. In order to dry the agent and improve the polarization performance, heating is preferable.
Although the heating conditions vary depending on the type of the adhesive, for example, when the adhesive is aqueous, it is preferably 30 ° C. or higher, more preferably 40 to 100 ° C., and particularly preferably 50 to 90 ° C. It is more preferable in terms of performance and production efficiency that these processes are manufactured in a consistent line.

-Performance of polarizing plate-
As the optical properties and durability (storability in short term and long term) of a polarizing plate comprising a protective film, a polarizer, and a support related to the present invention, a commercially available super high contrast product (for example, Sanlitz Co., Ltd.) It is preferable to have a performance equivalent to or better than that of HLC2-5618, manufactured by HLC.
Specifically, the visible light transmittance is 42.5% or more, and the degree of polarization {(Tp−Tc) / (Tp + Tc)} 1/2 ≧ 0.9995 (where Tp is parallel transmittance and Tc is orthogonal transmission) The change rate of the light transmittance before and after being left in an atmosphere of 60 ° C. and a humidity of 90% RH for 500 hours and 80 ° C. in a dry atmosphere is 3 based on the absolute value. % Or less, more preferably 1% or less. The rate of change in the degree of polarization is preferably 1% or less, more preferably 0.1% or less, based on the absolute value.

<Specific example>
An example of the liquid crystal display device of the present invention is shown in FIG. The liquid crystal display device includes a liquid crystal layer 7 in which the liquid crystal bends with respect to the substrate surface when a voltage is applied, that is, black display, and a liquid crystal cell including substrates 6 and 8 sandwiching the liquid crystal layer 7.
The substrates 6 and 8 have a liquid crystal surface subjected to alignment treatment, and the direction of the arrow RD is the rubbing direction. The arrow RD is indicated by a broken-line arrow in the case of the back surface.
Polarizing films 1 and 101 are disposed so as to sandwich the liquid crystal cell. The polarizing films 1 and 101 are arranged such that their transmission axes 2 and 102 are orthogonal to each other and at an angle of 45 degrees with the RD direction of the liquid crystal layer 7 of the liquid crystal cell.
Cellulose acylate films 3a and 103a and optically anisotropic layers 5 and 9 are arranged between the polarizing films 1 and 101 and the liquid crystal cell, respectively. In the cellulose acylate films 3a and 103a, the slow axes 4a and 104a are arranged in parallel to the directions of the transmission axes 2 and 102 of the polarizing films 1 and 101 adjacent to each other. The optically anisotropic layers 5 and 9 have optical anisotropy expressed by the orientation of the liquid crystalline compound.

An alignment film (not shown) is formed on the surface of the substrates 6 and 8 that contacts the liquid crystal molecules 7 (hereinafter also referred to as “inner surface”). The orientation of the liquid crystal molecules 7 is controlled in a parallel direction with a pretilt angle. Further, on the inner surfaces of the substrates 6 and 8, a transparent electrode (not shown) capable of applying a voltage to the liquid crystal layer made of the liquid crystal molecules 7 is formed.
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, more preferably 0.2 to 1.5 μm. Is more preferably 0.2 to 1.2 μm, and particularly preferably 0.6 to 0.9 μm. In these ranges, since the white display luminance when white voltage is applied is high, a bright and high-contrast display device can be obtained.
The liquid crystal material to be used is not particularly limited. For example, in an embodiment in which an electric field is applied between the substrates 6 and 8, the dielectric anisotropy is positive so that the liquid crystal molecules 7 respond in parallel to the electric field direction. It is preferable to use a liquid crystal material.

  For example, when the liquid crystal cell is an optically compensated birefringence (OCB) mode liquid crystal cell, a nematic liquid crystal material having a positive dielectric anisotropy between the substrates 6 and 8, Δn = 0.08, and Δε = 5. Etc. can be used. Although there is no restriction | limiting in particular about the thickness d of a liquid-crystal layer, When using the said nematic liquid-crystal material, it can set to about 6 micrometers, for example. The brightness at the time of white display changes depending on the magnitude of the product Δn · d of the thickness d and the refractive index anisotropy Δn when white voltage is applied, so that sufficient brightness can be obtained when white voltage is applied. Is preferably set so that Δn · d of the liquid crystal layer in the non-application state is in the range of 0.6 to 1.5 μm.

In addition, in an OCB mode liquid crystal display device, the addition of a chiral material generally used in a TN mode liquid crystal display device is rarely used to degrade dynamic response characteristics, but to reduce alignment defects. May be added. In addition, the multi-domain structure is advantageous for adjusting the alignment of the liquid crystal molecules in the boundary region between the domains.
Here, the “multi-domain structure” refers to a structure in which one pixel of a liquid crystal display device is divided into a plurality of regions.
For example, in the OCB mode, the multi-domain structure is preferable because the viewing angle characteristics of luminance and color tone are improved. Specifically, each pixel is composed of two or more (preferably 4 or 8) regions in which the initial alignment state of the liquid crystal molecules is different from each other, and the luminance and color tone bias depending on the viewing angle are averaged. Can be reduced. Further, the same effect can be obtained even if each pixel is composed of two or more different regions where the alignment direction of liquid crystal molecules continuously changes in a voltage application state.

The cellulose acylate films 3a and 103a have a ratio Re / Rth (450 nm) of in-plane retardation (Re) at a wavelength of 450 nm and retardation in a thickness direction (Rth) of Re / Rth (550 nm) at a wavelength of 550 nm. 0.4 to 0.95 times, Re / Rth (650 nm) at a wavelength of 650 nm satisfies a relationship of 1.05 to 1.9 times Re / Rth (550 nm), and Rth is 70 to 400 nm. It is preferable. The cellulose acylate films 3a and 103a may function as a support for the optically anisotropic layers 5 and 9, or may function as a protective film for the polarizing film 1 and the polarizing film 101. It may have both functions. That is, the polarizing film 1, the cellulose acylate film 3a, and the optically anisotropic layer 5, or the polarizing film 101, the cellulose acylate film 103a, and the optically anisotropic layer 9 are liquid crystal displays as an integrated laminate. It may be incorporated inside the apparatus or may be incorporated as individual members. Further, a configuration in which a protective film for a polarizing film is separately disposed between the cellulose acylate film 3a and the polarizing film 1 or between the cellulose acylate film 103a and the polarizing film 101 may be used. The protective film is preferably not disposed.
The slow axis 4a of the cellulose acylate film 3a and the slow axis 104a of the cellulose acylate film 103a are preferably substantially parallel or perpendicular to each other. When the slow axes 4a and 104a of the cellulose acylate films 3a and 103a are orthogonal to each other, the birefringence of the respective cellulose acylate films cancels each other, so that the optical characteristics of light vertically incident on the liquid crystal display device can be obtained. Deterioration can be reduced. Further, in the aspect in which the slow axes 4a and 104a are parallel to each other, when there is a residual phase difference in the liquid crystal layer, the phase difference can be compensated by birefringence of the protective film.

  Regarding the transmission axes 2 and 102 of the polarizing films 1 and 101, the slow axis directions 4a and 104a of the cellulose acylate films 3a and 103a, and the alignment direction of the liquid crystal molecules 7, the materials used for each member, the display mode, The optimum range is adjusted according to the laminated structure of the members. That is, the transmission axis 2 of the polarizing film 1 and the transmission axis 102 of the polarizing film 101 are arranged so as to be substantially orthogonal to each other. However, the liquid crystal display device of the present invention is not limited to this configuration.

The optically anisotropic layers 5 and 9 are disposed between the cellulose acylate films 3a and 103a and the liquid crystal cell.
The optically anisotropic layers 5 and 9 are layers formed from a composition containing a liquid crystal compound, for example, a rod-like liquid crystal compound or a discotic liquid crystal compound. In the optically anisotropic layer, the molecules of the liquid crystalline compound are fixed in a predetermined alignment state. In the plane of the cellulose acylate films 3a and 103a, the orientation average directions 5a and 9a of the molecular symmetry axis of the liquid crystalline compound in the optically anisotropic layers 5 and 9 at least at the interface on the cellulose acylate film 3a and 103a side The slow axes 4a and 104a intersect at approximately 45 degrees. When arranged in such a relationship, the optically anisotropic layer 5 or 9 does not cause light leakage by causing retardation to incident light from the normal direction. Similarly, at the interface on the liquid crystal cell side, the orientation average direction of the molecular symmetry axes of the optically anisotropic layers 5 and 9 is about 45 for the slow axes 4a and 104a in the planes of the cellulose acylate films 3a and 103a. Preferably.

  Further, the orientation average direction 5a on the polarizing film side (cellulose acylate film interface side) of the molecular symmetry axis in the liquid crystalline compound of the optically anisotropic layer 5 is substantially the same as the transmission axis 2 of the polarizing film 1 located closer. It is preferable to arrange at 45 degrees. Similarly, the orientation average direction 9a on the polarizing film side (cellulose acylate film interface side) of the molecular symmetry axis of the liquid crystalline compound of the optically anisotropic layer 9 is substantially the same as the transmission axis 102 of the polarizing film 101 located closer. It is preferable to arrange at 45 degrees. When arranged in such a relationship, optical switching can be performed according to the sum of the retardation generated in the optically anisotropic layer 5 or 9 and the retardation generated in the liquid crystal layer.

Next, the principle of image display of the liquid crystal display device of FIG. 2 will be described.
In a driving state in which a driving voltage corresponding to black is applied to the transparent electrodes (not shown) of the liquid crystal cell substrates 6 and 8, the liquid crystal molecules 7 in the liquid crystal layer are bend-aligned, and the in-plane retardation at that time is obtained. Is canceled by the in-plane retardation of the optically anisotropic layers 5 and 9, and as a result, the polarization state of the incident light hardly changes. Since the transmission axes 2 and 102 of the polarizing films 1 and 101 are orthogonal to each other, the light incident from the lower side (for example, the back electrode) is polarized by the polarizing film 101 and passes through the liquid crystal cells 5 to 8 while maintaining the polarization state. Passes and is blocked by the polarizing film 1. That is, the liquid crystal display device of FIG. 1 realizes an ideal black display in the driving state. On the other hand, in a driving state in which a driving voltage corresponding to white is applied to a transparent electrode (not shown), the liquid crystal molecules 7 in the liquid crystal layer have a bend alignment different from the bend alignment corresponding to black. It changes when the retardation is black. As a result, the in-plane retardation of the optically anisotropic layers 5 and 9 does not cancel, and the polarization state changes by passing through the liquid crystal cells 5 to 8, and passes through the polarizing film 1. That is, a white display is obtained.

  In the present invention, attention is also paid to Re / Rth which is a ratio of Re and Rth of the cellulose acylate film. This is because the value of Re / Rth determines the axes of two intrinsic polarizations in the propagation of light traveling obliquely through a biaxial birefringent medium. The two axes of intrinsic polarization in the propagation of light traveling obliquely through a biaxial birefringent medium are the major axis and the minor axis of the cross section formed when the refractive index ellipsoid is cut in the normal direction of the light traveling direction. Corresponds to the direction.

In the prior art, the Re / Rth values are almost the same, that is, the slow axis angles are almost the same regardless of the R, G, and B wavelengths. On the other hand, in the present invention, by defining the Re / Rth relationship separately for each of the R, G, and B wavelengths, both the slow axis and the retardation, which are factors that mainly determine the change in the polarization state, can be obtained. Optimization is performed for each wavelength of R, G, and B. When the oblique light passing through the cellulose acylate film passes through the optically anisotropic layer in which the alignment of the liquid crystal compound is fixed and further passes through the bend-aligned liquid crystal layer, the retardation and the upper and lower wavelengths at any wavelength. The Re / Rth value of the cellulose acylate film is adjusted according to the wavelength so that two factors that the apparent transmission axis of the polarizing film is deviated from the front can be compensated simultaneously.
Specifically, by increasing the Re / Rth of the cellulose acylate film as the wavelength increases, there is no difference in the polarization state in R, G, and B caused by the wavelength dispersion of the optically anisotropic layer and the liquid crystal cell layer. It becomes possible to do. As a result, complete compensation is possible and reduction in contrast is reduced. If the parameters of the film are determined with R, G, and B representing the entire visible light region, almost complete compensation can be achieved in the entire visible light region.

  Further, in the present invention, an OCB mode liquid crystal is formed by arranging an optically anisotropic layer having specific wavelength dispersion characteristics and a cellulose acylate film (optical compensation film of the present invention) having specific optical characteristics in combination. At the same time, the black light leakage and color misregistration on the front and left and right sides of the display device are improved.

  In addition, the liquid crystal display device of the present invention is not limited to the configuration shown in FIG. 2 and may include other members. For example, a color filter may be disposed between the liquid crystal cell and the polarizing film. Moreover, when using as a transmissive | pervious type | mold, the backlight which uses a cold cathode, a hot cathode fluorescent tube, a light emitting diode, a field emission element, or an electroluminescent element as a light source can be arrange | positioned on a back surface.

  The liquid crystal display device of the present invention includes an image direct view type, an image projection type, and a light modulation type. The present invention is particularly effective when applied to an active matrix liquid crystal display device using a three-terminal or two-terminal semiconductor element such as a thin film transistor (TFT) or a metal-insulator-metal (MIM). Furthermore, a mode applied to a passive matrix liquid crystal display device represented by a Super-Twisted Nematic (STN) type called time-division driving is also effective.

Examples of the present invention will be described below, but the present invention is not limited to the following examples.
Example 1
-Production of cellulose acetate film-
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.
[Composition of cellulose acetate solution]
Cellulose acetate with an acetylation degree of 60.9%: 100 parts by weight Triphenyl phosphate: 7.8 parts by weight Biphenyl diphenyl phosphate: 3.9 parts by weight Methylene chloride: 300 parts by weight Methanol・ 45 parts by mass

  In another mixing tank, 4 parts by mass of cellulose acetate (linter) having an acetylation degree of 60.9%, 25 parts by mass of a retardation increasing agent represented by the following structural formula, silica fine particles (average particle size: 20 nm) 0.5 Part by weight, 80 parts by weight of methylene chloride, and 20 parts by weight of methanol were added and stirred while heating to prepare a retardation increasing agent solution.

  1470 parts by mass of the retardation increasing agent solution was mixed with 470 parts by mass of the cellulose acetate solution, and the dope was prepared by sufficiently stirring. The mass ratio of the retardation increasing agent to cellulose acetate was 3.5%. After peeling the film having a residual solvent amount of 35% by mass from the band, the film was stretched at a stretching ratio of 30% using a film tenter at a temperature of 150 ° C., then the clip was removed and the film was dried at 130 ° C. for 45 seconds. A cellulose acetate film 1 was produced. The produced cellulose acetate film 1 had a residual solvent amount of 0.2% by mass and a film thickness of 88 μm.

  Similarly, 47.6 parts by mass of the retardation increasing agent solution was mixed with 470 parts by mass of the cellulose acetate solution, and the dope was prepared by sufficiently stirring. The mass ratio of the retardation increasing agent to cellulose acetate was 9%. After peeling the film with a residual solvent amount of 35% by mass from the band, the film was stretched at a temperature of 125 ° C. using a film tenter at a stretch ratio of 42%, then the clip was removed and the film was dried at 120 ° C. for 45 seconds. Cellulose acetate film 2 was produced. The produced cellulose acetate film 2 had a residual solvent amount of 0.2% by mass and a film thickness of 87 μm.

-Saponification treatment of cellulose acetate film-
One side of the produced cellulose acetate films 1 and 2 was coated with 25 ml / m ^{2 of} 1.5 N potassium isopropyl alcohol solution, allowed to stand at 25 ° C. for 5 seconds, then washed with running water for 10 seconds, 25 The surface of the film was dried by blowing air at 0 ° C. In this way, only one surface of the cellulose acetate film was saponified.

-Formation of alignment film-
On one surface of the saponified cellulose acetate films 1 and 2, an alignment film coating solution having the following composition was applied at 24 ml / m ² with a # 14 wire bar coater. The alignment film H-1 was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 90 ° C. for 150 seconds.
[Composition of alignment film coating solution]
Modified polyvinyl alcohol represented by the following structural formula (B): 10 parts by weight Water: 371 parts by weight Methanol: 119 parts by weight Glutaraldehyde (crosslinking agent): 0.5 parts by weight

However, in the structural formula (B), x = 86.33, y = 1.67, and z = 12.

-Measurement of surface free energy of alignment film-
Using the formed alignment film, the surface free energy was calculated using the following surface free energy measurement method. The results are shown in Table 1.
<< Surface Free Energy Measurement Method >>
D. K. Owens: Contact angles θ _H2O and θ of pure water H ₂ O and methylene iodide CH ₂ I ₂ measured with reference to J. Appl. Polym. Sci., 13, 1741 (1969) _{It calculated | required} by the following simultaneous equations (1) and (2) from _CH2I2 . Further, when the contact angle θ _glycerin was determined using glycerin instead of pure water, it was determined by the following simultaneous equations (2) and (3).
(Simultaneous equations)
_{(1): 1 + cosθ H2O} = 2√γs d (√γ H2O d / γ H2O v) + 2√γs h (√γ H2O h / γ H2O v)
_{(2): 1 + cosθ CH2I2} = 2√γs d (√γ CH2I2 d / γ CH2I2 v) + 2√γs h (√γ CH2I2 h / γ CH2I2 v)
^{_{γ H2O d = 21.8, γ H2O}} h = 51.0, γ H2O v = 72.8, γ CH2I2 d = 49.5, γ CH2I2 h = 1.3, γ CH2I2 v = 50.8

(3): 1 + cosθ _glycerin = 2√γs ^d (√γ _glycerin ^d / ^γ _glycerin ^v) + 2√γs ^h (√γ _glycerin ^h / ^γ _glycerin ^v)
γ- _glycerin ^d = 37.4, γ- _glycerin ^h = 26.0, γ- _glycerin ^v = 63.4
However, in the simultaneous equations, the dispersion force component of the gamma] s ^d is the surface free energy, the hydrogen bond component of the gamma] s ^h is the surface free energy, correspond respectively, the value represented by their sum γs v ⁽⁼ γs d ⁺ γs ^h ) is defined as surface free energy.
The contact angle was measured using a DropMaster 500 manufactured by Kyowa Interface Science Co., Ltd., after conditioning the sample for 24 hours at 25 ° C. and 60%, and then adding 10 μl of pure water and methylene iodide respectively under this condition. It was carried out 30 seconds after dropping on the sample surface.

-Rubbing treatment-
The cellulose acetate film on which the alignment film is formed is conveyed at a speed of 20 m / min, a rubbing roll (300 mm diameter) is set so as to be rubbed at 45 ° with respect to the longitudinal direction, and rotated at 650 rpm for alignment. The membrane installation surface was rubbed. The contact length with the rubbing roll was set to be 18 mm.

-Formation of optically anisotropic layer-
On the alignment film, a coating liquid for optically anisotropic layer having the following composition is conveyed at 20 m / min by rotating a wire bar of # 3.0 in 391 rotations in the same direction as the film conveying direction. It applied continuously to the alignment film surface.
[Composition of coating liquid for optically anisotropic layer]
Discotic liquid crystalline compound represented by the following structural formula (A): 91.00 parts by mass Ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) ... 9.00 Mass parts Cellulose acetate butyrate (CAB531-1, manufactured by Eastman Chemical Co., Ltd.) ... 1.00 mass parts Photopolymerization initiator (Irgacure 907, Ciba Geigy Corporation) ... 3.00 mass parts Sensitizer ( Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) ... 1.00 mass part Fluoro aliphatic group-containing copolymer (Megafac F780, manufactured by Dainippon Ink Co., Ltd.) ... 0.22 mass parts Methyl ethyl ketone ..226.34 parts by mass

  In the step of continuously heating from room temperature to 100 ° C., the solvent is dried, and then in the drying zone at 120 ° C., the film surface wind speed of the discotic liquid crystal compound layer is about 120 m so as to be 2.5 m / sec. The discotic liquid crystalline compound was aligned by heating for 2 seconds. Next, the film is transported to a drying zone at 80 ° C., and an ultraviolet ray with an illuminance of 600 mW is applied by an ultraviolet irradiation device (ultraviolet lamp: output 160 W / cm, emission length 1.6 m) with the film surface temperature being about 100 ° C. Irradiation was carried out for 4 seconds to advance the crosslinking reaction, and the discotic liquid crystalline compound was fixed to the orientation. Then, it was allowed to cool to room temperature and wound into a cylindrical shape to form a roll. Thus, the optical compensation film of Example 1 was produced.

-Measurement of optical properties-
A part of the produced optical compensation film was cut out and used as a sample to measure optical characteristics. Retardation of optically anisotropic layer measured by making light at a wavelength of 550 nm incident in the normal direction of the film with KOBRA 21ADH (manufactured by Oji Scientific Instruments) in an environment of 25 ° C. and 55% RH (Re ) The value was 30.0 nm. In addition, the angle (tilt angle) between the disc surface of the discotic liquid crystal compound in the optically anisotropic layer and the support surface changes continuously in the depth direction of the layer, and the average tilt angle obtained by the above-described method is It was 24.5 °.

-Measurement of surface free energy of liquid crystalline compounds-
Prepare a sample solution with the following composition, drop it onto a glass plate, and control the spin coat rotation speed so that the film thickness during drying is about 2 μm. When it was gradually heated to a temperature of + 5 ° C. at a temperature rising rate of 10 ° C./min, it was cured by UV irradiation (500 mJ / cm ² ) to prepare Sample L-1. From this, the surface free energy was calculated using the surface free energy measuring method described above. The results are shown in Table 2.
[Composition of measurement liquid]
Discotic liquid crystalline compound represented by the structural formula (A) ... 91.00 parts by mass Ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) ... 9.00 Part by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) ... 3.00 parts by mass Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) ... 1.00 parts by mass Methyl ethyl ketone ... Further, the dispersion force component in the surface free energy of the alignment film is γs ^d _(AL) and the dispersion force component γs ^d _(LC) in the surface free energy of the liquid crystalline compound is expressed by the following formula (A). The difference Δγs ^d between them was obtained. The results are shown in Table 3.
[Formula (A)]
Δγs ^d = γs ^d _(LC) −γs ^d _(AL)

-Evaluation of orientation-
It observed visually and with the microscope and evaluated by the following references | standards. The results are shown in Table 3.
○: The surface shape is uniform and the light is uniformly quenched at the extinction position.
X: The surface shape is non-uniform (such as stripes) and the light is not uniformly quenched even at the extinction position.

(Example 2)
In Example 1, in the modified polyvinyl alcohol represented by the structural formula (B) of the alignment film coating solution, a commercially available product (Poval PVA-103 (Kuraray Co., Ltd.)) with x = 98 and y = 2 was used. Then, the optical compensation film of Example 2 was produced in the same manner as in Example 1 except that the alignment film H-2 was formed, and the surface free energy of the alignment film H-2 was obtained in the same manner as in Example 1. Were evaluated for the average tilt angle, Δγs ^d , and orientation of the optical compensation film. The results are shown in Table 1 for the surface free energy of the alignment film H-2, and in Table 3 for the other cases.

(Example 3)
In Example 2, the optical compensation film of Example 3 was produced in the same manner as in Example 2 except that the optically anisotropic layer was produced using the coating liquid for optically anisotropic layer having the following composition. Sample L-2 was prepared from the liquid crystalline compound by the same method as in No. 1, and the surface free energy was evaluated, and the average tilt angle, Δγs ^d , and orientation of the optical compensation film were evaluated. The results are shown in Table 2 for the surface free energy of the liquid crystalline compound, and in Table 3 for the average tilt angle, Δγs ^d , and orientation.
[Composition of coating liquid for optically anisotropic layer]
Discotic liquid crystalline compound of Exemplified Compound D-337 ... 100.00 parts by mass Cellulose acetate butyrate (CAB531-1, manufactured by Eastman Chemical Co.) ... 1.00 parts by mass Photopolymerization initiator (Irgacure 907) 3.00 parts by mass Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) ... 1.00 parts by mass Fluoro aliphatic group-containing copolymer (Megafac F780 Dainippon) Ink Co., Ltd.) ... 0.22 parts by mass Methyl ethyl ketone ... 226.34 parts by mass

Example 4
In Example 3, the modified polyvinyl alcohol represented by the structural formula (B) of the alignment film coating solution was used except that the alignment film H-5 was formed with x = 96, y = 2, and z = 2. In the same manner as in Example 3, an optical compensation film of Example 4 was produced, and by the same method as in Example 3, the surface free energy for the alignment film H-5, the average tilt angle, Δγs ^d , and orientation for the optical compensation film Sex was evaluated respectively. Table 1 shows the results for the surface free energy of the alignment film H-5, and Table 3 shows the results for the other cases.

(Example 5)
In Example 3, the optical compensation film of Example 5 was produced in the same manner as in Example 3 except that the alignment film was changed to H-1 and the liquid crystal compound was changed to Exemplified Compound D-89. Sample L-3 was prepared from a liquid crystalline compound by the same method as in Example 3, and the surface free energy was evaluated, and the average tilt angle, Δγs ^d , and orientation of the optical compensation film were evaluated. The surface free energy of the liquid crystal compound is shown in Table 2, and the other results are shown in Table 3, respectively.

(Example 6)
In Example 3, the optical compensation film of Example 6 was produced in the same manner as in Example 3 except that the liquid crystalline compound was changed to Exemplified Compound D-112. Sample L-4 was prepared from the active compound, and the surface free energy was evaluated, and the average tilt angle, Δγs ^d , and orientation of the optical compensation film were evaluated. The surface free energy of the liquid crystal compound is shown in Table 2, and the other results are shown in Table 3, respectively.

(Example 7)
In Example 3, in the modified polyvinyl alcohol represented by the structural formula (B) of the alignment film coating solution, a commercially available product (Poval PVA-203 (manufactured by Kuraray Co., Ltd.)) with x = 88 and y = 12 was used. Then, an optical compensation film of Example 7 was produced in the same manner as in Example 3 except that the alignment film H-3 was formed and the liquid crystalline compound was changed to the exemplified compound D-351. In the same manner, the surface free energy of the alignment film H-3, the surface free energy of the sample L-5 prepared from the liquid crystalline compound, the average tilt angle, Δγs ^d , and the orientation of the optical compensation film Each was evaluated. The surface free energy of the alignment film H-3 is shown in Table 1, the surface free energy of the liquid crystal compound is shown in Table 2, and the other results are shown in Table 3.

(Example 8)
In Example 7, the optical compensation film of Example 8 was produced in the same manner as in Example 7 except that the liquid crystalline compound was changed to Exemplified Compound D-92. Sample L-6 was prepared from the active compound, and the surface free energy was evaluated, and the average tilt angle, Δγs ^d , and orientation of the optical compensation film were evaluated. The surface free energy of the liquid crystal compound is shown in Table 2, and the other results are shown in Table 3, respectively.

Example 9
In Example 3, the optical compensation film of Example 9 was produced in the same manner as in Example 3 except that the liquid crystalline compound was changed to Exemplified Compound D-346, and the liquid crystal was obtained in the same manner as in Example 3. Sample L-7 was prepared from the active compound, and the surface free energy was evaluated, and the average tilt angle, Δγs ^d , and orientation of the optical compensation film were evaluated. The surface free energy of the liquid crystal compound is shown in Table 2, and the other results are shown in Table 3, respectively.

(Example 10)
In Example 9, except that the alignment film was changed to H-5, the optical compensation film of Example 10 was produced in the same manner as in Example 9, and the optical compensation film was obtained in the same manner as in Example 9. The average tilt angle, Δγs ^d , and orientation were evaluated. The results are shown in Table 3.

(Comparative Example 1)
In Example 3, except that the alignment film was changed to H-1, the optical compensation film of Comparative Example 1 was produced in the same manner as in Example 3, and the optical compensation film was obtained in the same manner as in Example 3. The average tilt angle, Δγs ^d , and orientation were evaluated. The results are shown in Table 3.

(Comparative Example 2)
In Example 3, except that the alignment film was changed to H-3, an optical compensation film of Comparative Example 2 was produced in the same manner as in Example 3, and the optical compensation film was obtained in the same manner as in Example 3. The average tilt angle, Δγs ^d , and orientation were evaluated. The results are shown in Table 3.

(Comparative Example 3)
In Example 3, in the modified polyvinyl alcohol represented by the structural formula (B) of the alignment film coating solution, a commercially available product (Poval PVA-403 (manufactured by Kuraray Co., Ltd.)) with x = 78 and y = 22 was used. Then, an optical compensation film of Comparative Example 3 was prepared by the same method as in Example 3 except that the alignment film H-4 was formed. Energy was evaluated for the average tilt angle, Δγs ^d , and orientation for the optical compensation film, respectively. The results are shown in Table 1 for the surface free energy of the alignment film H-4, and in Table 3 for the other cases.

(Comparative Example 4)
In Example 6, the optical compensation film of Comparative Example 4 was produced in the same manner as in Example 6 except that the alignment film was changed to H-1, and the optical compensation film was obtained in the same manner as in Example 6. The average tilt angle, Δγs ^d , and orientation were evaluated. The results are shown in Table 3.

(Comparative Example 5)
In Example 6, an optical compensation film of Comparative Example 5 was produced in the same manner as in Example 6 except that the alignment film was changed to H-3, and the optical compensation film was obtained in the same manner as in Example 6. The average tilt angle, Δγs ^d , and orientation were evaluated. The results are shown in Table 3.

(Comparative Example 6)
In Example 6, an optical compensation film of Comparative Example 6 was produced in the same manner as in Example 6 except that the alignment film was changed to H-4, and the optical compensation film was obtained in the same manner as in Example 6. The average tilt angle, Δγs ^d , and orientation were evaluated. The results are shown in Table 3.

From the results of Table 1, it is easy to increase the value of the hydrogen bond component γs ^h _(AL) of the surface free energy in the alignment film by increasing the ratio of the vinyl alcohol units in the polyvinyl alcohol, thereby γs ^d _(AL). It was found that the value of can be easily reduced. Therefore, it was found that Δγs ^d can be adjusted by the ratio of the vinyl alcohol units.

From the results of Table 3, it was found that the optical compensation films of Examples 1 to 10 having Δγs ^d of −4.0 erg / cm ² or more had good orientation.

(Example 11)
-Production of polarizing plate-
A polarizing film was prepared by adsorbing iodine to the stretched polyvinyl alcohol film, and the optical compensation film of Example 1 was attached to one side of the polarizing film using a polyvinyl alcohol-based adhesive. The transmission axis of the polarizing film and the slow axis of the phase difference plate were arranged in parallel.
A commercially available cellulose acetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) was subjected to saponification treatment and attached to the opposite side of the polarizing film using a polyvinyl alcohol-based adhesive to produce a polarizing plate.

-Mounting evaluation in liquid crystal display devices-
-Preparation of bend alignment liquid crystal cell-
A polyimide film was provided as an alignment film on a glass substrate with an Indium Tin Oxide (ITO) electrode, and the alignment film was rubbed. The obtained two glass substrates were opposed to each other so that the rubbing directions were parallel to each other, and the cell gap was set to 4.0 μm. A bend-aligned liquid crystal cell was prepared by injecting a liquid crystal compound (ZLI1132, manufactured by Merck & Co., Inc.) having a Δn of 0.1396 into the cell gap.
Two produced polarizing plates were bonded so as to sandwich the produced bend alignment cell. The optically anisotropic layer of the polarizing plate faced the cell substrate, and the rubbing direction of the liquid crystal cell and the rubbing direction of the optically anisotropic layer facing it were antiparallel.
A rectangular wave voltage of 55 Hz was applied to the liquid crystal cell. A normally white mode of 2V white display and 5V black display was set. The voltage with the lowest transmittance at the front, that is, the black voltage was determined.

-Evaluation of color shift-
With respect to the liquid crystal cell on which the polarizing plate using the optical compensation film of Example 1 was attached, the conoscope “ConoScope ^™ ” (manufactured by autotronic-MELCHERS (Germany)) had an azimuth angle of 0 degrees and a polar angle of 60 degrees The color shift with an azimuth angle of 180 degrees and a polar angle of 60 degrees was measured. The results are shown in Table 4.

(Example 12)
In Example 11, color misregistration was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 2. The results are shown in Table 4.

(Example 13)
In Example 11, a color shift was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 3. The results are shown in Table 4.

(Example 14)
In Example 11, color misregistration was evaluated in a liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 4. The results are shown in Table 4.

(Example 15)
In Example 11, color misregistration was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 5. The results are shown in Table 4.

(Example 16)
In Example 11, color misregistration was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 6. The results are shown in Table 4.

(Example 17)
In Example 11, a color shift was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 7. The results are shown in Table 4.

(Example 18)
In Example 11, color misregistration was evaluated in a liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 8. The results are shown in Table 4.

Example 19
In Example 11, color misregistration was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 9. The results are shown in Table 4.

(Example 20)
In Example 11, a color shift was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Example 10. The results are shown in Table 4.

(Comparative Example 7)
In Example 11, a color shift was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Comparative Example 1. The results are shown in Table 4.

(Comparative Example 8)
In Example 11, color misregistration was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Comparative Example 2. The results are shown in Table 4.

(Comparative Example 9)
In Example 11, a color shift was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Comparative Example 3. The results are shown in Table 4.

(Comparative Example 10)
In Example 11, color misregistration was evaluated in a liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Comparative Example 4. The results are shown in Table 4.

(Comparative Example 11)
In Example 11, a color shift was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Comparative Example 5. The results are shown in Table 4.

(Comparative Example 12)
In Example 11, a color shift was evaluated in the liquid crystal display device in the same manner as in Example 11 except that a polarizing plate was produced using the optical compensation film of Comparative Example 6. The results are shown in Table 4.

In Table 4, in Comparative Examples 7 to 12, streaks of the optical compensation film occurred frequently, and color misregistration could not be measured.

  From the results of Table 4, it was found that in Examples 11 to 20 provided with polarizing plates prepared using the optical compensation film of the present invention in the liquid crystal display device, the color shift was small. In particular, in Examples 13 to 20 in which the compound represented by the above general formula (DI) was used as the liquid crystalline compound, it was found that color misregistration was further improved and it was preferable.

In the optical compensation film of the present invention, the difference between the dispersion force component in the surface free energy of the liquid crystalline compound and the dispersion force component in the surface free energy of the alignment film is set to −4.0 erg / cm ² or more. By using a discotic liquid crystalline compound, it is possible to easily control the retardation of the optically anisotropic layer in the optical compensation film, so that it can be suitably used for a polarizing plate in a liquid crystal display device. It can use suitably for an apparatus.
The liquid crystal display device of the present invention optically compensates the liquid crystal cell, can improve the contrast and reduce the color shift depending on the viewing angle direction, and can be suitably used for mobile phones, monitors for personal computers, televisions, liquid crystal projectors, etc. Can do.

FIG. 1 is a schematic diagram illustrating an example of an optically anisotropic layer. FIG. 2 is a schematic diagram illustrating an example of a liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Polarizing plate 2,102 ... Transmission axis 3a, 103a ... Cellulose acylate film 4a, 104a ... Slow axis 5, 9 ... Optical anisotropic layer

Claims (6)

And an alignment film, and a optically anisotropic layer containing a liquid crystal compound, the dispersion force component gamma] s in the surface free energy of the dispersion force component gamma] s d _^(LC) and the alignment layer on the surface free energy of the liquid crystal compound ^d _The optical compensation film, wherein the difference from _(AL) satisfies the following formula: γs ^d _(LC) −γs ^d _(AL) ≧ −4.0 erg / cm ² .   The optical compensation film according to claim 1, wherein the liquid crystalline compound is a discotic liquid crystalline compound. The optical compensation film according to claim 1, wherein the liquid crystalline compound contains at least one compound represented by the following general formula (DI).
However, Y < ₁₁ >, Y < ₁₂ >, and Y < ₁₃ > represent either a methine and a nitrogen atom each independently in general formula (DI). L ₁ , L ₂ , and L ₃ each independently represent a single bond or a divalent linking group. H ₁ , H ₂ , and H ₃ each independently represent any of the following general formula (DI-A) and the following general formula (DI-B). R ₁ , R ₂ , and R ₃ each independently represent the following general formula (DI-R).
In the general formula (DI-A), respectively the YA ₁ and YA ₂ independently represents any of methine and nitrogen atoms. XA represents an oxygen atom, a sulfur atom, methylene, or imino. * Represents a position where L _{1 to} L ₃ are bonded, and ** represents a position where R _{1 to} R ₃ are bonded.
However, the general formula (DI-B), YB ₁ and YB ₂ represent either each independently methine or nitrogen atom. XB represents an oxygen atom, a sulfur atom, methylene, or imino. * Represents a position where L _{1 to} L ₃ are bonded, and ** represents a position where R _{1 to} R ₃ are bonded.
[General formula (DI-R)]
*-(-L ₂₁ -M) n ₁ -L ₂₂ -L ₂₃ -Q ₁
However, * represents the position couple | bonded with the 5-membered ring in general formula (DI) in the said general formula (DI-R). L ₂₁ represents a single bond or a divalent linking group, and L ₂₂ represents —O—, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH. —, —SO ₂ —, —CH ₂ —, —CH═CH—, and —C≡C— are represented, and L ₂₃ represents —O—, —S—, —C (═O) —, — It represents a divalent linking group selected from the group consisting of SO ₂ —, —NH—, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. M represents a divalent linking group having at least one cyclic structure. Q ₁ each independently represents either a polymerizable group or a hydrogen atom. n ₁ represents an integer of 0-4.   The optical compensation film according to claim 1, wherein the liquid crystal compound has an average inclination angle of 45 ° or less.   The optical compensation film according to claim 1, wherein the alignment film contains a vinyl alcohol compound.   A liquid crystal display device comprising at least one optical compensation film according to claim 1.