JP2010217708A - Optical anisotropic film, method of producing the same, substrate for liquid crystal cell, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical anisotropic film useful for optical compensation of a liquid crystal display device. <P>SOLUTION: A biaxial optical anisotropic film having a twisted spiral structure is formed by emitting polarization to a composition containing at least one polymerizable liquid crystal compound and at least one optically active compound which may be racemized by light. The optically active compound is expressed by general formula (3), for example (L<SP>4</SP>expresses a 3C or higher divalent linking group, Q expresses a polymerizable group, and L<SP>5</SP>expresses a bivalent linking group). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optically anisotropic film, a method for producing the same, a liquid crystal cell substrate having the optically anisotropic film, and a liquid crystal display device.

  Various liquid crystal display devices have been proposed as liquid crystal display devices. Above all, the VA (Vertically Aligned) mode has wide contrast viewing angle characteristics in all directions as a wide viewing angle mode, and has already been widely used in television as a TV application. Has appeared. In the VA mode liquid crystal display device, optical anisotropic films having various characteristics are used for optical compensation in order to reduce light leakage and color shift that occur in an oblique direction during black display.

For example, as an optical compensation sheet that contributes to an improvement in color viewing angle characteristics of a VA mode liquid crystal display device, a retardation plate that satisfies predetermined optical characteristics is proposed, and a modified polycarbonate is used as the material thereof (Patent Document 1). reference).
Further, it has been proposed to use a deformed twisted spiral structure biaxial film and a uniform twisted spiral structure biaxial film for optical compensation of a liquid crystal display device (see Patent Documents 2 and 3). The biaxial film having a deformed twisted helical structure described in Patent Document 2 has an in-plane retardation, but needs to be irradiated with UV under nitrogen and has a large load in the process stage. In addition, regarding the biaxial film having a uniform twisted spiral structure described in Patent Document 3, since the polarized light irradiation is performed after the non-polarized light irradiation, the matrix is cured at the stage of the first non-polarized light irradiation, and thereafter With polarized light irradiation, in-plane retardation is poor.

JP 2004-37837 A Special table 2008-505369 Special table 2008-505370 gazette

  An object of the present invention is to provide a novel optical anisotropic film useful for optical compensation of a liquid crystal display device and a method capable of easily producing an optical anisotropic film useful for optical compensation of a liquid crystal display device. And Another object of the present invention is to provide a liquid crystal cell and a liquid crystal display device using the optically anisotropic film.

Means for solving the above problems are as follows.
[1] Biaxial optical anisotropy of a deformed twisted helical structure formed by irradiating a composition containing at least one polymerizable liquid crystal compound and at least one optically active compound racemized by light with polarized light Sex membrane.
[2] The optically anisotropic film according to [1], wherein an in-plane slow axis exists in a direction parallel to the irradiated polarized light.

[3] The optically anisotropic film according to [1] or [2], which is substantially transparent to light having a reflection wavelength of less than 400 nm and a wavelength of 380 to 780 nm.
[4] The optically anisotropic film according to any one of [1] to [3], wherein the composition contains an achiral liquid crystal compound.
[5] The optically anisotropic film according to any one of [1] to [4], wherein the optically active compound is a compound having a binaphthyl skeleton or a bis (tetrahydronaphthyl) skeleton:
[6] The optically different compound according to any one of [1] to [4], wherein the optically active compound is a compound represented by the following general formula (1) or general formula (2): Isotropic membrane:

(In the general formulas (1) and (2), R ¹ represents a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted group. And represents a substituted alkoxy group, L ¹ represents a divalent linking group, and the general formulas (1) and (2) have axial asymmetry of either (R) or (S).
[7] The optically anisotropic film according to any one of [1] to [6], wherein the optically active compound has a polymerizable group.
[8] A liquid crystal cell substrate comprising a substrate and the optically anisotropic film according to any one of [1] to [7] on the substrate.
[9] A liquid crystal display device comprising the optically anisotropic film according to any one of [1] to [7].

[10] The liquid crystal display device according to [9], which is a VA mode liquid crystal display device.
[11] The liquid crystal display device according to [9] or [10], wherein the optically anisotropic film is provided in a liquid crystal cell.
[12] The liquid crystal display device according to [11], wherein the optically anisotropic film is disposed in each region corresponding to each pixel in the liquid crystal cell.
[13] An optically active compound represented by the general formula (3).

(L ⁴ represents a divalent linking group having 3 or more carbon atoms, Q represents a polymerizable group, and L ⁵ represents a divalent linking group.)
[14] A method for producing a deformed twisted helical structure biaxial optically anisotropic film,
Applying a composition comprising at least one polymerizable liquid crystal compound and at least one optically active compound racemized by light; and thereafter
Irradiating the composition with polarized light,
The manufacturing method which does not include the process of irradiating non-polarized light before the said polarized light irradiation.
[15] A composition for producing a deformed twisted helical structure biaxial optically anisotropic film, comprising at least one polymerizable liquid crystal compound and at least one optically active compound racemized by light A composition comprising.

It is the schematic for demonstrating an example of the manufacturing method of the liquid crystal cell which has the optically anisotropic film | membrane of this invention inside. It is a schematic sectional drawing which shows an example of the liquid crystal cell which has the board | substrate for liquid crystal cells of this invention. It is a schematic sectional drawing which shows an example of the liquid crystal display device of this invention.

Hereinafter, the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
Further, in this specification, a “group” such as an alkyl group may have a substituent or may not have a substituent unless otherwise specified. Therefore, for example, in the case of “an alkyl group having a carbon number of A to B”, the alkyl group may or may not have a substituent. Moreover, when it has a substituent, it means what is the range of carbon number AB including carbon number in this substituent.

In this specification, Re (λ) and Rth (λ) each represent in-plane retardation (nm) and retardation in the thickness direction (nm) at wavelength λ. In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments). When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (if there is no slow axis, any in-plane film The light of wavelength λ nm is incident from each of the inclined directions in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction (with the direction of the rotation axis as the rotation axis). KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value. In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative. In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (11) and (12).

注記：上記のＲｅ（θ）は法線方向から角度θ傾斜した方向におけるレターデーション値を表し、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘ及びｎｙに直交する方向の屈折率を表す。ｄは膜厚を表す。

Note: Re (θ) represents the retardation value in the direction inclined by the angle θ from the normal direction, nx represents the refractive index in the slow axis direction in the plane, and ny is the direction orthogonal to nx in the plane. Nz represents the refractive index in the direction orthogonal to nx and ny. d represents a film thickness.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) and the tilt axis (rotating axis). In each of the 10 degree steps, light of wavelength λ nm is incident from the inclined direction and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or WR is calculated. In the above measurement, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59).
The KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness.

  Also, the sign of Rth is when the phase difference measured by injecting light having a wavelength of 550 nm from the direction inclined + 20 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis) exceeds Re Is positive and negative is below Re. However, in a sample with | Rth / Re | of 9 or more, it was tilted by + 40 ° with respect to the film normal direction with the in-plane fast axis as the tilt axis (rotation axis) using a polarizing microscope with a free rotation base. In the state, the case where the slow axis of the sample which can be determined using the polarizing plate inspection plate is parallel to the film plane is positive, and the case where the slow axis is in the thickness direction of the film is negative.

In the present specification, λ refers to 611 ± 5 nm, 545 ± 5 nm, and 435 ± 5 nm for R, G, and B, respectively, and refers to 545 ± 5 nm or 590 ± 5 nm unless otherwise specified.
In the present specification, “substantially” for the angle means that the error from the exact angle is within a range of less than ± 5 °. Further, the error from the exact angle is preferably less than 4 °, more preferably less than 3 °. With regard to retardation, “substantially” means that the retardation is within ± 5%. Further, Re is not 0 means that Re is 5 nm or more. Further, the refractive index measurement wavelength indicates a wavelength of 550 nm unless otherwise specified. In this specification, “visible light” refers to light having a wavelength of 400 nm to 700 nm.

1. TECHNICAL FIELD The present invention relates to an optically anisotropic film having a deformed twisted helical structure. The optically anisotropic film having a deformed twisted helical structure means an optically anisotropic film containing an optically anisotropic material having a deformed twisted helical structure. Here, the optically anisotropic material may be a material formed from a polymerizable material that can usually form a cholesteric structure. In the present invention, such a polymerizable material is at least one of a polymerizable liquid crystal compound and light. A composition containing at least one optically active compound that is racemized by the above method is used. More specifically, the present invention provides a liquid crystal composition containing at least one optically active compound that is racemized by light after cholesteric alignment (referred to a state in which the liquid crystal composition is aligned in a cholesteric alignment) and then irradiation with polarized light. The present invention relates to an optically anisotropic film having a deformed twisted helical structure. The optically anisotropic film of the present invention exhibits retardation generated due to deformation of the helical structure, that is, optical biaxiality, and is useful for optical compensation of liquid crystal display devices, particularly VA mode liquid crystal display devices. It is.
Hereinafter, materials and manufacturing methods that can be used for manufacturing the optically anisotropic film of the present invention will be described.

1. -1 Optically Active Compound Racemized by Light The optically active compound racemized by light is not particularly limited as long as it is a compound racemized by light. Preferable examples include optically active compounds represented by the following general formula (1) or (2).
By using an optically active compound racemized by light together with a liquid crystalline compound and using it as a chiral agent, the orientation of the liquid crystalline compound can be controlled, and the helical pitch of the liquid crystalline compound can be changed by light irradiation. . In particular, the optically active compound represented by the general formula (1) or (2) is a compound that can greatly change the twisting power (HTP: helical twisting power) of the helical structure of the coexisting liquid crystal compound.

The optically active compound represented by the following general formula (1) or (2) has axial asymmetry of either (R) or (S). The bicyclic moiety is racemized into a mixture of (R) and (S) isomers by light irradiation.

R ¹ in the general formulas (1) and (2) is a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted group. Represents a substituted alkoxy group, L ¹ represents a divalent linking group, and general formulas (1) and (2) have axial asymmetry of either (R) or (S). Among these, R ¹ is preferably a substituted or unsubstituted alkynyl group or a substituted or unsubstituted alkenyl group.

Substituted or unsubstituted alkynyl group R ¹ represents, it is preferable that the total number of carbon atoms is 2 to 30 are preferred, especially 2 to 20. As the substituent of the substituted alkynyl group, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, and a cyano group are preferable, and in particular, an aryl group, An acyloxy group is preferred. Examples of the substituted or unsubstituted aryl group include an ethynyl group, a phenylethynyl group, and a 4-acetyloxyphenylethynyl group.

The substituted or unsubstituted alkenyl group represented by R ¹ is preferably —C (R ² ) ═CH ₂ , —CH═C (R ³ ) H, —CH═C (R ⁴ ) ₂ —, particularly is preferably _{^{-C (R 2) = CH 2}} . R ² and R ³ represent an aryl group, and R ⁴ represents an alkoxycarbonyl group, an aryloxycarbonyl group, or a cyano group.

The substituted or unsubstituted aryl group represented by R ² may be a heterocyclic ring, preferably having a total carbon atom number of 4 to 40, particularly preferably 4 to 30. The substituent is preferably a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, or a cyano group, and particularly an electron such as an alkyl group, an alkenyl group, or an alkoxy group. Donating groups are preferred. As the heterocyclic ring, a pyridine ring, a pyrimidine ring, a furan ring, and a benzofuran ring are preferable, and a pyridine ring and a pyrimidine ring are particularly preferable. Examples of the substituted or unsubstituted aryl group include β-naphthyl group, 4-methylphenyl group, 4-vinylphenyl group, 4-butyloxyphenyl group, and 4-benzoyloxyphenyl group.

The substituted or unsubstituted aryl group represented by R ³ may be a heterocyclic ring, and preferably has 6 to 40 total carbon atoms, particularly preferably 6 to 30. As the substituent of the substituted aryl group, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, and a cyano group are preferable, and in particular, an acyl group and an alkoxycarbonyl group Group, an aryloxycarbonyl group, an acyloxy group, an electron-withdrawing group such as a cyano group is preferable. As the heterocyclic ring, for example, a pyridine ring, a pyrimidine ring, a furan ring, and a benzofuran ring are preferable, and a pyridine ring and a pyrimidine ring are particularly preferable. Examples of the substituted or unsubstituted aryl group include a phenyl group, a 4-butoxycarbonylphenyl group, a 4-naphthyloxycarbonylphenyl group, and a 6-methoxycarbonylnaphthalen-2-yl group.

R ⁵ represents a substituted or unsubstituted alkoxycarbonyl group, preferably having 2 to 30 total carbon atoms, particularly preferably 2 to 20 carbon atoms. As the substituent of the substituted aryl group, a halogen atom, an aryl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an aryloxycarbonyl group, an acyloxy group, and a cyano group are preferable, particularly a halogen atom, an aryl group, an alkoxy group, An acyloxy group is preferred. Examples of the substituted or unsubstituted alkoxycarbonyl group include a methoxycarbonyl group, a decyloxycarbonyl group, a trifluoroethoxycarbonyl group, a methoxyethoxycarbonyl group, and an acetyloxyethoxycarbonyl group.

The substituted or unsubstituted aryloxycarbonyl group represented by R ⁵ may be a heterocyclic ring, preferably an aryloxycarbonyl group having 5 to 40 total carbon atoms, and particularly preferably an aryloxycarbonyl group having 5 to 30 carbon atoms. As the substituent, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an arylcarbonyl group, an acyloxy group, and a cyano group are preferable, and a halogen atom, an alkyl group, an alkoxy group, and an acyloxy group are particularly preferable. , An arylcarbonyl group and a cyano group are preferred. Examples of the substituted or unsubstituted aryloxycarbonyl group include a phenoxycarbonyl group, a biphenylcarbonyl group, a β-naphthyloxycarbonyl group, a 4-phenoxycarbonyl group, and a methoxyphenoxycarbonyl group.

The substituted or unsubstituted aryl group represented by R ¹ preferably has 6 to 40 total carbon atoms, and particularly preferably 6 to 30 carbon atoms. As the substituent of the substituted aryl group, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, and a cyano group are preferable, particularly an alkyl group, Electron donating groups such as alkenyl groups and alkoxy groups are preferred. Examples of the substituted or unsubstituted aryl group include β-naphthyl group, 4-methylphenyl group, 4-vinylphenyl group, 4-butyloxyphenyl group, and 4-benzoyloxyphenyl group.

The substituted or unsubstituted alkyl group represented by R ¹ preferably has 2 to 15 total carbon atoms, and particularly preferably 2 to 10 carbon atoms. As the substituent of the substituted alkyl, a halogen, an aryl group, an alkoxy group, an acyl group, and a cyano group are preferable, and a halogen and a cyano group are particularly preferable. Examples of the substituted or unsubstituted alkyl group represented by R ¹ include a 3-chloropropyl group, a 4-cyanobutyl group, and a 4-fluorobutyl group.

The substituted or unsubstituted alkoxy group represented by R ¹ preferably has 2 to 15 total carbon atoms, and particularly preferably 2 to 10 carbon atoms. As the substituent of the substituted alkoxy, a halogen, an aryl group, an alkoxy group, an acyl group, and a cyano group are preferable, and a halogen and a cyano group are particularly preferable. Examples of the substituted or unsubstituted alkoxy group represented by R ¹ include a 3-chloropropoxy group, a 4-cyanobutoxy group, and a 2-bromoethoxy group.

In addition, the substituted or unsubstituted alkynyl group represented by R ¹ and / or the substituted or unsubstituted aryl group represented by R ² may be substituted with any of the following groups.

In the above formula, W represents a hydrogen atom or a methyl group, and k represents 0 or 1.

In the above formula, L ′ represents a single bond or a divalent linking group. L ′ is a single bond; a divalent linking group selected from the group consisting of —O—, —CO—, —S—, —NH—, an alkylene group, an alkenylene group, an alkynylene group, an arylene group, and combinations thereof. Is preferred. The total number of carbon atoms of L ′ is preferably 1-15, more preferably 1-10, and even more preferably 2-6.

L ¹ is a divalent radical, preferably, have a substituent is 2 -O- alkylene group or ^-O-L also, and more preferably ^-O-L 2 -O- .

L ² is a divalent group which may have a substituent, preferably has 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms. More preferably, it is 1-10. Examples of such a divalent group include an alkylene group and a divalent group represented by the following structural formula.

In the structural formula, R ⁵ to R ⁸ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, or an acylamino group, and R ⁹ represents an alkyl group or an aryl group, and R ¹⁰ and R ¹¹ each independently represents an alkyl group, an aryl group, or an alkenyl group. L ^{′ ′} represents a divalent group other than a phenylene group. The alkylene group and R ⁵ to R ¹¹ may further have a substituent having the following structural formula as another substituent.

Among L ² , the following are particularly preferable.

Specific examples of the optically active compound represented by the general formula (1) or (2) include compounds described in the tables of paragraphs [0041] to [0043] described in JP-A No. 2002-179669. Can do.
In addition, the compound represented by the general formula (1) or (2) is preferably an optically active compound represented by the following general formula (3).

L ⁴ represents a divalent linking group having 3 or more carbon atoms, Q represents a polymerizable group, and L ⁵ represents a divalent linking group.

The divalent linking group having 3 or more carbon atoms represented by L ⁴ includes —O—, —CO—, —S—, —NH—, an alkylene group, an alkenylene group, an alkynylene group, an arylene group, and combinations thereof. And divalent linking groups selected from the group. A particularly preferred group is a divalent linking group in which —O—, an alkylene group, and —O— are bonded in this order. The divalent linking group L ⁴ represents halogen, cyano group, an alkoxy group and may have a substituent group (group bonded to the main chain). L total carbon number of ⁴ is preferably 3 to 30, more preferably from 3 to 20, more preferably 3 to 10.

  As the polymerizable group represented by Q, an acryloyl group, a methacryloyl group or a styryl group is preferable, and an acryloyl group and a methacryloyl group are particularly preferable.

The linking group represented by L ⁵ has the same meaning as L ¹ , and the preferred range is also the same as L ¹ .

Specific examples of the optically active compound (optically active compound represented by the general formula (1) or (2)) that can be used in the photoracemating chiral agent are shown below, but the present invention is limited to the following specific examples. It is not done.

1. -2 Liquid Crystal Compound A composition containing a liquid crystal compound is used for producing the optically anisotropic film of the present invention. In general, liquid crystal compounds can be classified into a rod type and a disk type from the shape. In addition, there are low and high molecular types, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In this embodiment, any liquid crystal compound can be used, but a rod-like liquid crystal compound is preferably used.
The liquid crystal compound used in the present invention may be a liquid crystal compound capable of cholesteric alignment in the presence of the optically active compound. The liquid crystal compound itself does not need to be an optically active substance, and an achiral liquid crystal compound is used. can do. In the present invention, it is preferable to use an achiral liquid crystal compound from the viewpoint of easy control of expression of optical characteristics in the process of producing an optically anisotropic film. From the same viewpoint, in the present invention, it is preferable to use a liquid crystal compound that does not contain a functional group such as a photoisomerization group or a photodimerization group.

  Examples of rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolans, and alkenylcyclohexylbenzonitriles are preferably used. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used. The polymer liquid crystalline compound is a polymer compound obtained by polymerizing a rod-like liquid crystalline compound having a low molecular polymerizable group. The rod-like liquid crystalline compound having a low molecular polymerizable group which is particularly preferably used is a rod-like liquid crystalline compound represented by the following general formula (I).

Formula (I): Q ¹ -L ¹ -A ¹ -L ³ -ML ⁴ -A ² -L ² -Q ²
However, in said general formula (I), Q < ¹ > and Q < ² > are each independently a reactive group, L < ¹ >, L < ² >, L < ³ > and L < ⁴ > are each independently a single bond or a bivalent coupling group. However, at least one of L ³ and L ⁴ is preferably —O— or O—CO—O—. A ¹ and A ² each independently represent a spacer group having 2 to 20 carbon atoms. M represents a mesogenic group.

Hereinafter, the rod-like liquid crystal compound having a polymerizable group represented by the general formula (I) will be described in more detail. In the formula, Q ¹ and Q ² are each independently a polymerizable group. The polymerizable group is preferably a polymerizable group capable of addition polymerization reaction or condensation polymerization reaction. For example, when having a polymerizable group in the partial structure of the general formula (1) (specifically, in Z), it may be a polymerizable group capable of undergoing a polymerization reaction with the polymerizable group. Examples of polymerizable groups are shown below.

Examples of the divalent linking group represented by L ¹ , L ² , L ³ , and L ⁴ include —O—, —S—, —CO—, —NR ² —, —CO—O—, —O—. ^{CO-O -, - CO-} NR 2 -, - NR 2 -CO -, - O-CO -, - O-CO-NR 2 -, - NR 2 -CO-O-, and ^NR 2 -CO-NR ^A divalent linking group selected from the group consisting of ^2- is preferable. R ² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. In this case, at least one of L ³ and L ⁴ is preferably —O— or O—CO—O— (carbonate group). In the formula (I), Q ¹ -L ¹ and Q ² -L ² -are CH ₂ ═CH—CO—O—, CH ₂ ═C (CH ₃ ) —CO—O—, and CH ₂ ═C ( Cl) -CO-O-CO- O- are _{preferable, CH 2 = CH-CO-} O- is most preferable.

A ¹ and A ² represent spacer groups having 2 to 20 carbon atoms. An aliphatic group having 2 to 12 carbon atoms is preferable, and an alkylene group is particularly preferable. The spacer group is preferably chain-like and may contain oxygen atoms or sulfur atoms that are not adjacent to each other. The spacer group may have a substituent and may be substituted with a halogen atom (fluorine, chlorine, bromine), a cyano group, a methyl group, or an ethyl group.

Examples of the mesogenic group represented by M include all known mesogenic groups. In particular, a group represented by the following general formula (II) is preferable.
Formula ^{(II): - (- W} 1 -L 5) n -W 2 -
However, in said general formula (II), W < ¹ > and W < ² > respectively independently represent a bivalent cycloaliphatic group, a bivalent aromatic group, or a bivalent heterocyclic group, and L < ⁵ > is a single bond. Alternatively, a linking group is represented, and specific examples of the linking group include specific examples of groups represented by L ^{1 to} L ⁴ in the formula (I), —CH ₂ —O—, and O—CH ₂ —. It is done. n represents 1, 2 or 3.

Examples of W ¹ and W ² include 1,4-cyclohexanediyl, 1,4-phenylene, pyrimidine-2,5-diyl, pyridine-2,5diyl, 1,3,4-thiadiazole-2,5-diyl. 1,3,4-oxadiazole-2,5-diyl, naphthalene-2,6-diyl, naphthalene-1,5-diyl, thiophene-2,5-diyl, pyridazine-3,6-diyl, etc. Is mentioned. In the case of 1,4-cyclohexanediyl, there are trans isomers and cis isomers, but either isomer may be used, and a mixture in any proportion may be used. More preferably, it is a trans form. W ¹ and W ² may each have a substituent. Examples of the substituent include a halogen atom (for example, fluorine, chlorine, bromine, iodine, etc.), a cyano group, an alkyl group having 1 to 10 carbon atoms (for example, a methyl group, ethyl group, propyl group, etc.), and 1 to 10 carbon atoms. Alkoxy groups (for example, methoxy group, ethoxy group, etc.), C1-C10 acyl groups (for example, formyl group, acetyl group, etc.), C1-C10 alkoxycarbonyl groups (for example, methoxycarbonyl group, ethoxycarbonyl, etc.) Group), an acyloxy group having 1 to 10 carbon atoms (for example, acetyloxy group, propionyloxy group, etc.), nitro group, trifluoromethyl group, difluoromethyl group, and the like.

  Preferred examples of the basic skeleton of the mesogenic group represented by the general formula (II) are shown below. These may be substituted with the above substituents.

  Although the example of a compound represented by the said general formula (I) is shown below, it is not limited to these. The compound represented by the general formula (I) can be synthesized by the method described in JP-T-11-513019.

1. -3 Preparation of liquid crystal composition In the liquid crystal composition used for forming the optically anisotropic film of the present invention, the content of the optically active compound satisfying the above characteristics is the total mass of the composition (coating liquid and other solvents). In the aspect to include, it is preferable that it is 5-40 mass% in the total mass of the solid content except a solvent), and it is more preferable that it is 10-30 mass%. When using 2 or more types, it is preferable that a sum total is the said range. Moreover, in the aspect containing a liquid crystal compound, it is preferable that a liquid crystal compound is 60-95 mass% in the total mass of a composition, and it is more preferable that it is 70-90 mass%.

  Moreover, in the aspect in which the said composition contains an achiral liquid crystal compound with the said optically active compound, it is preferable that the ratio with respect to the said achiral liquid crystal compound of the said optically active compound is 10-30 mass%, 12-20 More preferably, it is mass%. When the ratio of the optically active compound to the achiral liquid crystalline compound is less than 10% by mass, the reflection wavelength becomes visible, and the optically anisotropic film may be colored. When the ratio of the optically active compound to the achiral liquid crystalline compound exceeds 30% by mass, the cholesteric alignment state may not be achieved.

1. 3-1 Additive The composition may contain an additive.
Alignment agent:
The composition may contain an aligning agent for improving the orientation of the liquid crystal compound. For example, by containing at least one compound represented by the general formulas (1) to (3) described in [0068] to [0072] of JP-A-2007-121986, the general formula (I) A compound having a partial structure represented by the formula can be substantially horizontally aligned, and a stable cholesteric alignment can be obtained by using it together with an optically active compound.

  The amount of the compound represented by any one of the general formulas (11) to (13) is preferably 0.01% by mass to 20% by mass with respect to the total mass of the liquid crystal composition, and 0.01% by mass to 10 mass% is more preferable, and 0.02 mass% to 1 mass% is particularly preferable. In addition, the compounds represented by the general formulas (11) to (13) may be used alone or in combination of two or more.

Polymerization initiator:
The liquid crystal composition used in the present invention is preferably curable, and for that purpose, at least one of the optically active compound and a component such as a liquid crystal compound added if desired has a polymerizable group. If you do. In order to perform the polymerization reaction quickly and obtain a cured film having sufficient hardness, the liquid crystal composition preferably contains a polymerization initiator. A polymerization initiator is selected according to the polymerization reaction to advance. The available polymerization reaction may be either a thermal polymerization reaction using a thermal polymerization initiator or a photopolymerization reaction using a photopolymerization initiator, but a photopolymerization reaction is more preferable. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatics. Group acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketone (US patents) No. 3549367), acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (described in U.S. Pat. No. 4,221,970).

The amount of the photopolymerization initiator used is preferably 0.01% by mass to 20% by mass, and more preferably 0.5% by mass to 5% by mass as a solid content in the liquid crystal composition.
The liquid crystal composition used for producing the optically anisotropic film of the present invention preferably does not contain a dichroic polymerization initiator.

1. -3-2 Solvent The composition used to form the optically anisotropic film of the present invention is preferably prepared as a coating solution. As a solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of the organic solvent include amides (eg, N, N-dimethylformamide); sulfoxides (eg, dimethyl sulfoxide); heterocyclic compounds (eg, pyridine); hydrocarbons (eg, benzene, hexane); alkyl halides (eg, chloroform, dichloromethane); Esters (eg, methyl acetate, butyl acetate); ketones (eg, acetone, methyl ethyl ketone); ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane); 1,4-butanediol diacetate, and the like. Among these, alkyl halides and ketones are particularly preferable. Two or more organic solvents may be used in combination.

2. Manufacturing method of optically anisotropic film The optically anisotropic film of the present invention is a glass substrate or the like that supports a composition containing at least one photopolymerizable liquid crystal compound and at least one optically active compound racemized by light. It can be formed by irradiating polarized light after being applied to the body surface and cholesteric oriented.
The composition can be applied to the support surface by various conventionally known methods. As will be described later, when the optically anisotropic film of the present invention is arranged in a liquid crystal cell and is formed for each region corresponding to each pixel, the surface of the support corresponding to each pixel is utilized using an inkjet method. It is preferable to apply to.

  When the coating film is dried after the composition is applied to the surface, for example, the molecules of the coexisting achiral liquid crystal compound are cholesterically aligned by the twisting force of the optically active compound as the solvent evaporates. If desired, heat aging may be performed for 1 to 5 minutes in the liquid crystal phase temperature range.

Next, the composition in the cholesteric alignment state is irradiated with polarized light to distort the twisted helical structure of the cholesteric alignment.
The optically anisotropic film of the present invention has an in-plane slow axis in the direction in which the polarized light to be irradiated and the vibration plane are parallel.

Irradiation energy of the polarized light irradiation is preferably ^{20mJ / cm 2 ~10J / cm 2} , further preferably 100 to 800 mJ / cm ^2. The illuminance is preferably 20 to 1000 mW / cm ^2, more preferably 50 to 500 mW / cm ^2, further preferably 100 to 350 mW / cm ^2. The irradiation wavelength preferably has a peak at 300 to 450 nm, and more preferably has a peak at 350 to 400 nm.

When heated after irradiation with polarized light, the orientation is matured and a larger in-plane retardation can be obtained.
The heating temperature is preferably 50 ° C to 250 ° C, more preferably 50 ° C to 200 ° C, and still more preferably 70 ° C to 170 ° C.

In the method of the present invention, the step of irradiating non-polarized light is not included before the step of irradiating polarized light. Thereby, an in-plane phase difference can be fully expressed. In addition, after irradiating polarized light, it is preferable to further irradiate with light for improving heat resistance. The light irradiation for improving the heat resistance after the polarized light irradiation may be polarized light irradiation or non-polarized light irradiation. Light irradiation energy for curing is preferably ^{20mJ / cm 2 ~10J / cm 2} , further preferably 100 to 800 mJ / cm ^2. The illuminance is preferably 20 to 1000 mW / cm ^2, more preferably 50 to 500 mW / cm ^2, further preferably 100 to 350 mW / cm ^2. In the case of irradiation with polarized light, the irradiation wavelength preferably has a peak at 300 nm to 450 nm, and more preferably has a peak at 350 nm to 400 nm. In the case of non-polarized light irradiation, it preferably has a peak at 200 nm to 450 nm, and more preferably has a peak at 250 nm to 400 nm.

  The thickness of the optically anisotropic film of the present invention is preferably 0.1 μm to 20 μm, and more preferably 0.5 μm to 10 μm.

3. Optical Characteristics of Optical Anisotropic Film Since the optical anisotropic film of the present invention exhibits in-plane retardation Re, it can satisfy, for example, characteristics required for a biaxial film.
Since the optically anisotropic film of the present invention has biaxiality, it is particularly suitable for optical compensation of a VA mode liquid crystal display device. Biaxial films are generally understood to have different nx, ny and nz. As an example, a material exhibiting optical characteristics satisfying nx>ny> nz can be mentioned. The optically anisotropic film of the present invention has a Re (550) of about 20 to 300 nm and an Nz value (where Nz = Rth (550) / Re (550) +0.5) is 1.1 to 7. It can function as a biaxial film exhibiting properties of about zero. That is, the optically anisotropic film of the present invention can be used for optical compensation of a liquid crystal display device as an alternative to a conventionally used biaxial film, and particularly used for optical compensation of a VA mode liquid crystal display device. Suitable for When the optically anisotropic film of the present invention is used as a biaxial film (for example, for optical compensation of a VA mode liquid crystal display device), Nz is preferably 1.5 to 8.0. More preferably, it is 0.0 to 7.0.
The in-plane retardation Re (550) at a wavelength of 550 nm is preferably 20 nm to 300 nm, more preferably 20 nm to 200 nm, and still more preferably 20 nm to 100 nm. The Re of the biaxial optically anisotropic film necessary for VA compensation is about 50 nm. If the Re and Nz factors deviate from the appropriate values, the viewing angle dependency may be reduced.

  One embodiment of the optically anisotropic film of the present invention is an optically anisotropic film characterized by being substantially transparent to light having a reflection wavelength of less than 400 nm and a wavelength of 380 to 780 nm. The transparency of the optically anisotropic film is determined by the refractive index of the liquid crystal material used and the pitch of the helix. The pitch of the helix is proportional to the amount of chiral agent added, and if it is added in a large amount, the pitch also increases. Since the reflection wavelength is the product of the refractive index of the liquid crystal material and the pitch of the helix, the value of the reflection wavelength can be determined by adjusting the addition amount of the chiral agent according to the refractive index of the liquid crystal material.

4). 3. Use of optically anisotropic film -1 In-cell optically anisotropic film The optically anisotropic film of the present invention can exhibit desired optical characteristics using polarized light without the need for an alignment film. This is advantageous, and particularly, it is advantageous to form in a region corresponding to each pixel in the liquid crystal cell.
In the aspect formed in the liquid crystal cell, it is preferable that the optical characteristics of the optical anisotropic film are adjusted to optical characteristics that are optimal for viewing angle compensation when R light, G light, and B light are incident. . That is, the optical anisotropic film formed in the region corresponding to the R layer of the color filter layer is optimally adjusted for viewing angle compensation when R light is incident, and corresponds to the G layer. The optical characteristics of the optical anisotropic film formed in the region are optimally adjusted for the viewing angle compensation when G light is incident, and the optical characteristics of the optical anisotropic film formed in the region corresponding to the B layer Is preferably adjusted optimally for viewing angle compensation when B light is incident. The optical characteristics of the optically anisotropic film can be adjusted to a preferable range depending on, for example, the type of the optically active compound and the liquid crystal compound, the type of the alignment control agent or the addition amount thereof, the film thickness, and the polarization irradiation conditions. it can.
Further, the optical anisotropic film itself may function as a color filter. In that case, R color, G color and B color pigments are added to the composition for forming an optically anisotropic film.

  As an example of a method of forming the optically anisotropic film of the present invention on the surface of the liquid crystal cell substrate for each region corresponding to each pixel, a method using an ink jet method can be given. More specifically, a fluid containing the optically active compound is applied in an area separated by a black matrix by an ink jet method, and then desired optical properties are expressed by polarized light irradiation, and then heat aging as required. Can be produced.

Hereinafter, an example of a method for producing a liquid crystal cell having the optically anisotropic film of the present invention inside will be described in detail with reference to FIG.
On a transparent substrate 11 made of glass or the like, for example, a negative black matrix resist material is used, and a black matrix 12 (partition) of a dot pattern is formed using a photolithography method, and a plurality of fine regions separated by the partition 12 a is formed (FIG. 1A). In the formation of the black matrix 12, there is no particular limitation on the black matrix forming material and the forming process, and there is no problem if a black matrix pattern can be formed even by a method other than a method using a photolithography method using a resist material. . The pattern of the black matrix 12 is not limited to the dot pattern, and the arrangement of the color filters to be formed is not particularly limited, and may be any of dot arrangement, stripe arrangement, mosaic arrangement, delta arrangement, and the like.

The black matrix 12 is preferably subjected to plasma treatment with a gas containing F atoms (CF ₄ or the like) after pattern formation, and the surface thereof is subjected to ink repellent treatment. In addition to the plasma treatment, the black matrix 12 may be made to contain an ink repellant in the black matrix material, or the black matrix may be formed from a material that exhibits ink repellency with respect to the glass substrate 11. May be.

  Next, a fluid 13 ′ containing the optically active compound is ejected to a fine area a separated by a black matrix 12 that has been subjected to ink repellent treatment if desired using an ink jet apparatus, and the fluid is introduced into the fine area a. A layer made of (FIG. 1B) is formed. After the discharge of the solution is completed, the film is cholesterically oriented by heat aging and is irradiated with polarized light, thereby distorting the twisted helical structure and developing in-plane anisotropy to form the optical anisotropic film 13 (FIG. 1 (c)). Heating may be performed as desired before irradiation with polarized light, during irradiation with polarized light, or after irradiation with polarized light. In that case, a heating device may be used.

  On the first optically anisotropic film 13 formed in this way, a second ink discharge is performed with the color filter ink liquid 14 '(FIG. 1 (d)), this is dried, and desired The second color filter layer 14 is formed by exposure or the like ((e)).

  There are no particular restrictions on the ejection conditions of the ink or the like when forming the optically anisotropic film 13 and the color filter layer 14, but the viscosity of the fluid for forming the optically anisotropic film or the ink for forming the color filter layer is high. It is preferable from the viewpoint of ejection stability that the ink is ejected at a reduced ink viscosity at room temperature or under heating (for example, 20 ° C. to 70 ° C.). It is preferable to keep the temperature of the ink or the like as constant as possible because fluctuations in the viscosity of the ink or the like greatly affect the droplet size and droplet ejection speed as they are and cause image quality degradation.

  The inkjet head (hereinafter also simply referred to as a head) is not particularly limited, and various known ones can be used. Continuous type and dot on demand type can be used. Among the dot-on-demand types, the thermal head is preferably a type having an operation valve as described in JP-A-9-323420 for discharging. In the piezo head, for example, heads described in European Patent A277,703, European Patent A278,590 and the like can be used. The head preferably has a temperature control function so that the temperature of the composition can be controlled. It is preferable to set the injection temperature so that the viscosity at the time of injection is 5 to 25 mPa · s, and to control the composition temperature so that the fluctuation range of the viscosity is within ± 5%. Moreover, as a drive frequency, it is preferable to operate | move at 1-500 kHz.

The formation order of the optical anisotropic film 13 and the color filter layer 14 may be switched, that is, the optical anisotropic film 13 may be laminated on the color filter layer 14. . Such an embodiment can be produced by switching the order of the step of forming the optical anisotropic film 13 and the step of forming the color filter layer 14 in the above manufacturing method example.
Further, the optically active compound may be mixed with the color filter forming ink.

  The optical anisotropy film 13 may be formed using fluids such as the same kind of solution, and has an optimal optical anisotropy according to the hue of the color filter layer 14 formed thereon. It may be formed using fluids containing different materials and / or different amounts in order to develop. In the case of using different solutions depending on the hue of the color filter layer at the time of forming the optical anisotropic film 13, the respective solutions may be discharged and then dried at the same time. A drying process may be performed. Further, when forming the color filter layer 14, for example, after all ink liquids for forming the R layer, the G layer, and the B layer are ejected, drying may be performed at the same time. A drying process may be performed. Further, the color of the color filter is not necessarily limited to the three colors of red, green, and blue, and may be a multi-primary color filter.

  In this manner, after forming the optical anisotropic film and the color filter layer for each region separated by the black matrix 12 corresponding to each pixel of the first substrate, the first substrate, The substrate is pasted together. Before the bonding, a transparent electrode layer and / or an alignment layer may be formed on the color filter layer 14. For example, as described in Japanese Patent Application Laid-Open No. 11-248921 and Japanese Patent No. 3255107, a base is formed by overlapping colored resin compositions forming a color filter, a transparent electrode is formed thereon, and further necessary Accordingly, it is preferable from the viewpoint of cost reduction that the spacers are formed by overlapping the protrusions for split orientation.

  A liquid crystal cell can be manufactured by injecting a liquid crystal material into a space between the opposing surfaces of the first substrate and the second substrate to form a liquid crystal layer. The first substrate is preferably arranged with the surface on which the optically anisotropic film and the color filter layer are formed on the inside, that is, the opposing surface. Thereafter, a polarizing plate, an optical compensation film, and the like can be attached to the outer surfaces of both substrates, respectively, to produce a liquid crystal display device.

  In the example of the manufacturing method, when the liquid for forming the optical anisotropic film and the ink liquid for forming the color filter layer are arranged at predetermined positions, a black matrix as a partition is formed, and then an inkjet method is used. Therefore, the optically anisotropic film and the color filter layer can be accurately formed in a predetermined region on the first substrate. Therefore, it can be manufactured with a small number of steps without complicating the structure.

  In the above method, the example in which the optically anisotropic film and the color filter layer are formed in each fine region by using ink ejection by the ink jet method has been described. However, for example, a printing method other than the ink jet method is used. May be formed.

4). -2 Liquid crystal cell This invention relates also to the board | substrate for liquid crystal cells which has a board | substrate and the optically anisotropic film of this invention on it. One aspect of the substrate for a liquid crystal cell of the present invention includes a substrate, the optically anisotropic film of the present invention for compensating the viewing angle of the liquid crystal cell, and a color filter layer, and the optically anisotropic film comprises: The liquid crystal cell substrate has optical characteristics that are optimal for compensating the viewing angle of the liquid crystal cell depending on the hue of the color filter layer disposed below or above the color filter layer (for example, for each color of R, G, and B). The substrate material is not particularly limited as long as it is transparent, and for example, a metallic support, a metal-bonded support, glass, ceramic, a synthetic resin film, or the like can be used. Birefringence is preferably small, and glass, low birefringence polymer, and the like are preferable. In addition, on the surface of the substrate, an alignment film having an alignment regulating ability with respect to the liquid crystal material and a transparent electrode layer may be formed.

  The substrate for a liquid crystal cell of the present invention is further provided on the surface opposite to the side on which the optically anisotropic film is formed (the surface on the side disposed outside the liquid crystal cell when incorporated in a liquid crystal display device). You may have a 2nd optically anisotropic film. The second optical anisotropic film contributes to optical compensation of the liquid crystal cell together with the optical anisotropic film of the present invention disposed in the liquid crystal cell. The preferable range of the optical characteristics of the second optical anisotropic film varies depending on the mode of the liquid crystal display device used. For example, when a liquid crystal cell substrate for VA mode is used, the optically anisotropic film of the present invention may be disposed on the inner surface of the substrate, and the second optically anisotropic film may be disposed on the outer surface of the substrate. .

FIG. 2 shows a schematic cross-sectional view of an example of a liquid crystal cell having the liquid crystal cell substrate of the present invention.
The liquid crystal cell substrate shown in FIG. 2A has a pattern-like shape in which a black matrix 22 is formed as a partition on a transparent substrate 21 and is discharged by an inkjet method into a fine region separated by the partition. A color filter layer 23 and an optical anisotropic film 27 are formed. Furthermore, a transparent electrode layer 25 and an alignment layer 26 are provided thereon. Although FIG. 2 shows an embodiment in which the R, G, B color filter layers 23 are formed, a color filter layer composed of R, G, B, W (white) layers may be formed. The optically anisotropic film 27 is divided into R, G, and B regions, and has optimum retardation characteristics for the hues of the R, G, and B filter layers 23, respectively.

  Further, as shown in FIG. 2B, a second optical anisotropic film 24 that contributes to optical compensation together with the optical anisotropic film 27 may be disposed on the outer surface of the liquid crystal cell substrate. The second optical anisotropic film 24 may be arranged on the same color filter side substrate side as the optical anisotropic film 27 in the cell, or may be arranged on the counter substrate side although not shown. In general, a driving electrode such as a TFT array is often arranged on the counter substrate side, and may be arranged at any position on the counter substrate. However, in the case of an active drive type having a TFT, optical anisotropy is provided. From the heat resistance of the conductive film, it is preferably higher than the silicon layer.

4). -3 Liquid crystal display device TECHNICAL FIELD This invention relates to the liquid crystal display device which has the optically anisotropic film of this invention. The optically anisotropic film may be disposed outside the liquid crystal cell and between the liquid crystal cell and the polarizer, or may be disposed in the liquid crystal cell as described above. Moreover, you may further have the 2nd optical anisotropic film which contributes to optical compensation with the optical anisotropic film of this invention.
FIG. 3 is a schematic sectional view of an example of the liquid crystal display device of the present invention.
3 (a) and 3 (b) use the substrates of FIGS. 2 (a) and 2 (b) as upper substrates, respectively, and a glass substrate 21 having a transparent electrode layer 25 with TFT 32 and an alignment layer 26 thereon. Is a liquid crystal display device having a liquid crystal cell 37 with a liquid crystal 31 interposed therebetween. On both sides of the liquid crystal cell 37, a polarizing plate 36 made of a polarizing layer 33 sandwiched between protective layers 34 and 35 made of a cellulose acetate (TAC) film or the like is disposed. The protective layer 35 on the liquid crystal cell side may be a polymer film such as a TAC film that satisfies optical characteristics as an optical compensation sheet, or may be made of the same polymer film as the protective layer 34. Although not shown in the drawing, in the aspect of the reflective liquid crystal display device, only one polarizing plate is required on the observation side, and a reflective film is provided on the back surface of the liquid crystal cell or on the inner surface of the lower substrate of the liquid crystal cell. Of course, a front light can be provided on the liquid crystal cell observation side. Further, a transflective type in which a transmissive portion and a reflective portion are provided in one pixel of the display device is also possible. The display mode of the present liquid crystal display device is not particularly limited, and can be used for all transmissive, transflective, and reflective liquid crystal display devices. In particular, the present invention is effective for the VA mode where color viewing angle characteristics are desired to be improved.

  An example of the liquid crystal display device of the present invention is a VA mode liquid crystal display device. As a VA mode liquid crystal display device, a system using a negative C-plate and an A-plate for optical compensation and a system using a biaxial film for optical compensation are known. The optically anisotropic film of the present invention can be used as a biaxial film.

In the above, the example of the VA mode liquid crystal display device has been described. However, the optically anisotropic film of the present invention can also be used for optical compensation of liquid crystal display devices of other modes. TN mode liquid crystal cell retardation plates (optical compensation sheets) are described in JP-A-6-214116, US Pat. Nos. 5,583,679, 5,646,703, and German Patent 3,911,620A1. A retardation plate (optical compensation sheet) for liquid crystal cells in IPS mode or FLC mode is described in JP-A-10-54982. Further, a retardation plate (optical compensation sheet) for an OCB mode or HAN mode liquid crystal cell is described in US Pat. No. 5,805,253 and International Publication WO96 / 37804. Furthermore, a retardation plate (optical compensation sheet) for a liquid crystal cell in STN mode is described in JP-A-9-26572. A VA mode liquid crystal cell retardation plate (optical compensation sheet) is described in Japanese Patent No. 2866372. It can be used as an alternative to these optical compensation sheets.
Furthermore, there is an effect of using the optically anisotropic film of the present invention in combination with a polarizing plate for the purpose of preventing reflection of an electroluminescence device or a field emission display device.

The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.
Example 1
Exemplary compound (3-3) was synthesized according to the following scheme.

The compound (1-A) is obtained from (S) -2,2′-methylenedioxy-6,6′-dibromobinaphthol as a raw material with reference to the description in JP-A No. 2002-179669. Synthesized by a coupling reaction. Subsequent hydrolysis gave (1-B).
—Synthesis Example of Exemplary Compound (3-3) —
150.0 mg (280.6 mmol) of compound (1-B) and 96.9 mg (701.5 mmol) of potassium carbonate were dissolved in 10 ml of DMAc, and 250.0 mg of 4-sulfonic acid methyl-butyl acrylate was added dropwise to the solution. Stir at 0 ° C. for 3 hours. The reaction mixture was subjected to liquid separation with ethyl acetate and water, the ethyl acetate layer was distilled off, and the residue was purified by column chromatography to obtain 180 mg of a transparent oil. The yield was 41%.
¹ H-NMR (CDCl ₃ ): δ (ppm from tetramethylsilane) 7.96 (2H, d), 7.91 (2H, s), 7.56 (2H, d), 7.52-7.44 ( 8H, m), 7.15 (4H, s), 6.90 (4H, d), 6.42 (2H, dd), 6.12 (2H, dd), 5.83 (2H, dd), 5.70 (2H, s)

(Example 2) Preparation of liquid crystal cell substrate Preparation of coating liquid LC-1 for optically anisotropic film:
After preparing the following composition, it filtered with the polypropylene filter with the hole diameter of 0.2 micrometer, and used as coating liquid LC-1 for optical anisotropic films.
In addition, LC-1-1 is Tetrahedron Lett. It was synthesized according to the method described in Journal, Vol. 43, page 6793 (2002).
Composition of coating liquid LC-1 for optically anisotropic film:
Polymerizable liquid crystal Illustrative compound I-2 17.4% by mass
-Chiral agent Exemplified compound 3-3 2.6% by mass
1.4-butanediol diacetate 79.28% by mass
-0.02 mass% of horizontal alignment agent (LC-1-1) represented by the following structural formula
・ Irg-907 (Ciba Specialty Chemicals) 0.5% by mass
・ DETX (Nippon Kayaku Co., Ltd.) 0.2% by mass

Color filter composition:
Each RGB pixel composition having the composition shown in Table 1 was prepared.

The composition of the composition in Table 1 is as follows.
[R pigment dispersion-1 composition]
・ C. I. Pigment Red 254 8.0 mass%
5- [3-oxo-2- [4- [3,5-bis (3-diethylaminopropylaminocarbonyl) phenyl] aminocarbonyl] phenylazo] -butyroylaminobenzimidazolone 0.8% by mass
-Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio (weight average molecular weight 37,000) 8.0 mass%
Propylene glycol monomethyl ether acetate 83.2% by mass

[R pigment dispersion-2 composition]
・ C. I. Pigment Red 177 18.0 mass%
-Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio (weight average molecular weight 37,000) 12.0% by mass
・ Propylene glycol monomethyl ether acetate 70.0 mass%

[G pigment dispersion composition]
・ C. I. Pigment Green 36 18.0% by mass
-Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio (weight average molecular weight 37,000) 12.0% by mass
・ Cyclohexanone 35.0% by mass
・ Propylene glycol monomethyl ether acetate 35.0% by mass

[Binder 1 composition]
-Random copolymer of benzyl methacrylate / methacrylic acid = 78/22 molar ratio (weight average molecular weight 40,000) 27.0% by mass
Propylene glycol monomethyl ether acetate 73.0% by mass

[Binder 2 composition]
・ Benzyl methacrylate / methacrylic acid / methyl methacrylate = 38/25 /
Random copolymer of 37 molar ratio (weight average molecular weight 30,000) 27.0% by mass
Propylene glycol monomethyl ether acetate 73.0% by mass

[Binder 3 composition]
・ Benzyl methacrylate / methacrylic acid / methyl methacrylate = 36/22 /
Random copolymer of 42 molar ratio (weight average molecular weight 30,000) 27.0% by mass
Propylene glycol monomethyl ether acetate 73.0% by mass

[DPHA composition]
・ KAYARAD DPHA (Nippon Kayaku Co., Ltd.) 76.0% by mass
Propylene glycol monomethyl ether acetate 24.0% by mass

Preparation of R layer forming solution PP-R1:
The R layer forming liquid PP-R1 is first weighed in the amounts of R pigment dispersion 1, R pigment dispersion 2, and propylene glycol monomethyl ether acetate shown in Table 1 and mixed at a temperature of 24 ° C. (± 2 ° C.). And then stirred for 10 minutes at 150 rpm, then the amounts of methyl ethyl ketone, binder 2, DPHA solution, 2-trichloromethyl-5- (p-styrylmethyl) -1,3,4-oxadiazole, 2 , 4-Bis (trichloromethyl) -6- [4- (N, N-diethoxycarbonylmethyl) -3-bromophenyl] -s-triazine and phenothiazine were weighed and this was measured at a temperature of 24 ° C. (± 2 ° C.). Add in order and stir at 150 rpm for 10 minutes, then weigh out the amount of ED152 listed in the table above, mix at a temperature of 24 ° C. (± 2 ° C.) and stir at 150 rpm for 20 minutes And, further, weighed amounts of Megafac F-176PF according to Table 1, and stirred 30rpm30 minutes was added at a temperature 24 ℃ (± 2 ℃), was obtained by filtering with a nylon mesh # 200.

Preparation of G layer forming solution PP-G1:
The G-layer forming solution PP-G1 is first weighed in the amounts of G pigment dispersion, CF yellow EX3393, and propylene glycol monomethyl ether acetate listed in Table 1, mixed at a temperature of 24 ° C. (± 2 ° C.), and 150 rpm for 10 minutes. Stirring and then the amounts of methyl ethyl ketone, cyclohexanone, binder 1, DPHA solution, 2-trichloromethyl-5- (p-styrylmethyl) -1,3,4-oxadiazole, 2,4- Bis (trichloromethyl) -6- [4- (N, N-diethoxycarbonylmethyl) -3-bromophenyl] -s-triazine and phenothiazine are weighed out and added in this order at a temperature of 24 ° C. (± 2 ° C.). And stirred at 150 rpm for 30 minutes, and weighed out the megafac F-176PF in the amount shown in Table 1, and the temperature was 24 ° C. (± 2 ) Was added with stirring 30rpm5 minutes, and filtering the mixture through a nylon mesh # 200.

Preparation of B layer forming solution PP-B1:
B-layer forming solution PP-B1 is first weighed in the amounts of CF Blue EX3357, CF Blue EX3383 and propylene glycol monomethyl ether acetate listed in Table 1, mixed at a temperature of 24 ° C. (± 2 ° C.), and stirred at 150 rpm for 10 minutes. Then, the amounts of methyl ethyl ketone, binder 3, DPHA solution, 2-trichloromethyl-5- (p-styrylmethyl) -1,3,4-oxadiazole, and phenothiazine in the amounts shown in Table 1 are weighed and the temperature is 25. At a temperature of 40 ° C. (± 2 ° C.) and stirred at 150 rpm for 30 minutes. Further, the amount of Megafac F-176PF shown in Table 1 was weighed and the temperature was 24 It was obtained by adding at 0 ° C. (± 2 ° C.), stirring at 30 rpm for 5 minutes, and filtering through nylon mesh # 200.

Fabrication of a substrate having an optically anisotropic film:
A substrate having a black matrix formed on an alkali-free glass substrate was prepared.
As the R optical anisotropic film R-1, an optical anisotropic film coating liquid LC-1 obtained above is surrounded by a black matrix (light-shielding partition) using a piezo head. The droplets were deposited on the recesses to be formed and dried by heating at 140 ° C. for 2 minutes. Further, after aging for 2 minutes at a temperature of 65 ° C., this layer was immediately irradiated with polarized UV (illuminance: 200 mW / cm ² , irradiation amount: 200 mJ / cm ² ), and then heated and aged at 130 ° C. to a thickness of 2.9 μm. An optically anisotropic film R-1 was formed.
Similarly, the optically anisotropic films G-1 and B-1 for the G layer and the B layer were formed in fine regions where the G layer and the B layer were to be formed, respectively. By using the coating liquid LC-1 for optically anisotropic film and changing the droplet ejection amount, the thicknesses of the optically anisotropic films G-1 and B-1 were 2.8 μm and 2.6 μm, respectively.
In this embodiment, the conveying speed and the driving frequency are controlled in the portions corresponding to the R, G, and B pixels, and the coating liquid for each optical anisotropic film is formed in the concave portions corresponding to the desired R, G, and B. Struck.

Production of color filter layer:
PP-R1, PP-G1, and PP-B1, which are liquids for forming the R, G, and B layers obtained above, are determined in advance by using a piezo-type head in a recess surrounded by a light-shielding partition. The droplets were ejected at the positions, and R layer, G layer and B layer were formed respectively.
In this embodiment, the conveyance speed and the driving frequency are controlled for the portions corresponding to the R, G, and B pixels, respectively, and the R, G, and B are respectively set in the concave portions corresponding to the desired R, G, and B. And B-layer forming liquids PP-R1, PP-G1 and PP-B1 were ejected.
Thereafter, drying was performed at a temperature of 100 ° C., and heat treatment was further performed at a temperature of 200 ° C. for 1 hour to form a color filter pixel on the optically anisotropic film.

Phase difference measurement:
In-plane retardation Re (λ) at an arbitrary wavelength λ and ± 40 with a slow axis as a rotation axis by a parallel Nicol method using a fiber spectrometer (KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments)) The retardation when the sample was tilted was measured, Rth (λ) was calculated, and the Nz value was also obtained. With respect to R, G, and B, retardation was measured at wavelengths λ of 611 nm, 545 nm, and 435 nm, respectively.
The retardation of the optically anisotropic film was calibrated with the transmittance data of the substrate without the optically anisotropic film measured in advance, so that only the retardation of the optically anisotropic film was obtained. Table 2 shows the measurement results of the phase difference.

  From the results in Table 2, it can be understood that the formed optically anisotropic films R-1, G-1, and B-1 are biaxial.

Heat resistance test:
The Re (550) retention before and after performing the heat treatment at 230 ° C. for 3 hours was determined for the formed optically anisotropic film. Re (550) retention is the ratio of Re (550) after heat treatment to Re (550) before heat treatment. The results of Re (550) retention are shown in Table 3.

Formation of transparent electrode:
A transparent electrode film (having a thickness of 2000 mm) was formed on the produced color filter by sputtering of ITO.

Formation of alignment layer and liquid crystal cell formation:
Further, a polyimide alignment film was provided thereon. Next, glass beads having a particle diameter of 5 μm were sprayed. Further, an epoxy resin sealant containing spacer particles is printed at a position corresponding to the outer frame of the black matrix provided around the pixel group of the color filter, and the color filter substrate and the counter substrate are pressed at a pressure of 10 kg / cm. Pasted together. Next, the bonded glass substrate was heat-treated at a temperature of 150 ° C. for 90 minutes to cure the sealing agent to obtain a laminate of two glass substrates. This glass substrate laminate was degassed under vacuum, then returned to atmospheric pressure, and liquid crystal was injected into the gap between the two glass substrates to obtain a liquid crystal cell. A polarizing plate HLC2-2518 manufactured by Sanlitz Co., Ltd. was attached to both surfaces of the liquid crystal cell.

Fabrication of VA-LCD:
As a cold-cathode tube backlight for a color liquid crystal display device, a phosphor obtained by mixing BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn and LaPO ₄ : Ce, Tb at a mass ratio of 50:50 is green (G), Y ₂ O ₃ : Eu was red (R) and BaMgAl ₁₀ O ₁₇ : Eu was blue (B), and a white three-wavelength fluorescent lamp having an arbitrary color tone was produced. A liquid crystal cell provided with the above polarizing plate was placed on the backlight, and a VA-LCD of Example 1 was produced.

(Evaluation of VA-LCD of Example 2)
The black color of the liquid crystal display device of Example 2 produced was black at an azimuth angle of 45 degrees and a polar angle of 60 degrees, and the colors of azimuth angle 45 degrees polar angle 60 degrees and azimuth angle 180 degrees and polar angle 60 degrees. A shift was observed.
As a result of observing the produced liquid crystal display device of Example 2, it was confirmed that neutral black display was realized in both the front direction and the viewing angle direction.

Example 3
The optically anisotropic film coating liquid (a) prepared under the same conditions as in Example 2 and the chiral agent (3-3) contained in this coating liquid were converted into the following optically active compound (1-b) having no polymerizable group. The coating solution (b) was applied onto a slide glass with a polyimide alignment film by spin coating and dried by heating at 140 ° C. for 2 minutes. Furthermore, after aging for 2 minutes at a temperature 65 ° C., immediately after irradiation with polarized UV (illuminance 30 mW / cm ^2, irradiation amount 600 mJ / cm ²⁾ for this layer, 130 ° C. heated ripening, the optically anisotropic film Formed. For each, the normal direction (Re) of the film surface at a wavelength of 545 nm and the retardation value when tilted by 40 ° from the normal direction (Re (40)) were measured and compared, and the results shown in Table 4 were obtained. Became.

  From the results shown in Table 4, the example using the chiral agent having a polymerizable group (3-3) has a larger in-plane anisotropy than the example using the chiral agent having no polymerizable group. It can be seen that an optically anisotropic film can be produced.

Comparative Example 1
After preparing the following composition, it is filtered through a polypropylene filter having a pore size of 0.2 μm to prepare a coating solution for an optically anisotropic layer, and is applied onto a slide glass with a polyimide alignment film by spin coating. And dried for 2 minutes. Furthermore, after aging for 2 minutes at a temperature of 65 ° C., this layer was immediately irradiated with polarized UV in the presence of oxygen (illuminance 200 mW / cm ² , irradiation amount 200 mJ / cm ² ), and then heated and aged at 130 ° C. The curing of was insufficient. Although an attempt was made to form an optically anisotropic film with an illuminance of 270 mW / cm ² and an irradiation dose of 9000 mJ / cm ² , the film was not cured, but when this dichroic polymerization initiator was used, the film was sufficient in an oxygen atmosphere. Could not be hardened.

───────────────────────────────────――
Coating composition for optically anisotropic layer (%)
───────────────────────────────────――
Bar-shaped liquid crystal (Paliocolor LC242, manufactured by BASF Japan) 28.37
Chiral agent (Palicolor LC756, manufactured by BASF Japan) 3.30
Photopolymerization initiator (LC-2-1) 1.32
Additive (LC-1-2) 0.01
Methyl ethyl ketone 67.00
─────────────────────────────────────

LC-2-1:
It was synthesized by the method described in EP1388538A1.

Comparative Example 2
(Preparation of coating liquid LC-3 for optical anisotropic layer)
After preparing the following composition, it is filtered through a polypropylene filter having a pore size of 0.2 μm to prepare a coating solution for an optically anisotropic layer, and is applied by spin coating on a slide glass with a polyimide alignment film at 140 ° C. Heat-dried for 2 minutes. Furthermore, after aging for 2 minutes at a temperature of 65 ° C., this layer was immediately irradiated with polarized UV in the presence of oxygen (illuminance 200 mW / cm ² , irradiation amount 200 mJ / cm ² ), and then heated and aged at 130 ° C. The curing of was insufficient. Although an attempt was made to form an optically anisotropic film with an illuminance of 270 mW / cm ² and an irradiation dose of 9000 mJ / cm ² , the film was not cured, but when this dichroic polymerization initiator was used, the film was sufficient in an oxygen atmosphere. Could not be hardened.

──────────────────────────────────――
Coating composition for optically anisotropic layer (%)
──────────────────────────────────――
Rod-shaped liquid crystal (LC-3-1) 6.67
Rod-shaped liquid crystal (LC-3-2) 2.60
Chiral agent (LC-3-3) 21.07
Chiral agent (LC-3-4) 1.67
Chain transfer agent (LC-3-5) 0.67
Photopolymerization initiator (LC-3-6) 0.67
Methyl ethyl ketone 66.65
──────────────────────────────────――

LC-3-1:
Angew. Makromol. Chem. It was synthesized according to the method described in Journal, Vol. 183, p. 45 (1990).
LC-3-2:
It was synthesized by condensing 4- (6-acryloyloxyhexyloxy) benzoic acid synthesized by the method described in EP1174411B1 and 4-propylcyclohexylphenol (manufactured by Kanto Chemical).
LC-3-3:
4- (6-acryloyloxyhexyloxy) benzoic acid synthesized by the method described in EP 1174411B1 and 4-hydroxy-4 ′-(2-methylbutyl) biphenyl synthesized by the method described in WO / 2001040154A1 are condensed. And synthesized.
LC-3-4:
It was synthesized by the method described in EP1389199A1.
LC-3-5:
Hydroxypropyl acrylate (manufactured by Aldrich) was mesylated, reacted with 4-propylcyclohexylphenol (manufactured by Kanto Chemical), and then hydrogen sulfide was added for synthesis.
LC-3-6:
After 4-propylcyclohexylphenol (manufactured by Kanto Chemical Co., Ltd.) was triflated, a biphenyl compound was obtained by Suzuki coupling reaction with phenylboronic acid. Furthermore, after acylating the 4′-position of biphenyl with isobutyric chloride and aluminum chloride, the carbon at the α-position of the carbonyl was brominated with bromine and then converted into a hydroxyl group with an alkali.

Comparative Example 3
The following coating solution was prepared, applied onto a slide glass with a polyimide alignment film by spin coating, and dried by heating at 140 ° C. for 2 minutes. Furthermore, after aging for 2 minutes at a temperature of 65 ° C., this layer was immediately irradiated with polarized UV in the presence of oxygen (illuminance 200 mW / cm ² , irradiation amount 200 mJ / cm ² ), and then heated and aged at 130 ° C. The curing of was insufficient. Illuminance 270 mW / cm ^2, not cured but tried to formation of the optically anisotropic film by raising the dose 9000 mJ / cm ^2, sufficient film in an oxygen atmosphere in the case of using the dichroic polymerization initiator Could not be hardened.

Polymerizable liquid crystal Illustrative compound I-2 17.4% by mass
-Chiral agent R811 (Merck) 2.6% by mass
1.4-butanediol diacetate 79.28% by mass
-Horizontal alignment agent (LC-1-1) 0.02 mass%
-Photopolymerization initiator (LC-3-6) 0.7% by mass

11 Transparent substrate 12 Black matrix
13 Optical Anisotropy Film 14 Color Filter Layer 21 Transfer Substrate 22 Black Matrix (Partition Wall)
23 Color filter layer 24 Solid optical anisotropic film 25 Transparent electrode layer 26 Alignment layer 27 Patterning optical anisotropic film 31 Liquid crystal 32 TFT
33 Polarizing layer 34 Cellulose acetate film (polarizing plate protective film)
35 Cellulose acetate film or optical compensation sheet 36 Polarizing plate 37 Liquid crystal cell

Claims (15)

A biaxial optically anisotropic film having a deformed twisted helical structure formed by irradiating a composition containing at least one polymerizable liquid crystal compound and at least one optically active compound racemized by light with polarized light. The optically anisotropic film according to claim 1, wherein an in-plane slow axis exists in a direction parallel to the polarized light to be irradiated. The optically anisotropic film according to claim 1 or 2, which is substantially transparent to light having a reflection wavelength of less than 400 nm and a wavelength of 380 to 780 nm. The optically anisotropic film according to claim 1, wherein the composition contains an achiral liquid crystal compound. The optically anisotropic compound according to any one of claims 1 to 4, wherein the optically active compound is a compound having a binaphthyl skeleton or a bis (tetrahydronaphthyl) skeleton. The optically anisotropic compound according to any one of claims 1 to 4, wherein the optically active compound is a compound represented by the following general formula (1) or general formula (2):

(In the general formulas (1) and (2), R ¹ represents a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted group. And represents a substituted alkoxy group, L ¹ represents a divalent linking group, and the general formulas (1) and (2) have axial asymmetry of either (R) or (S). The optically anisotropic film according to any one of claims 1 to 6, wherein the optically active compound has a polymerizable group. The board | substrate for liquid crystal cells which has a board | substrate and the optically anisotropic film of any one of Claims 1-7 on this board | substrate. A liquid crystal display device comprising the optically anisotropic film according to claim 1. The liquid crystal display device according to claim 9, which is a VA mode liquid crystal display device. The liquid crystal display device according to claim 9, wherein the optically anisotropic film is provided in a liquid crystal cell. The liquid crystal display device according to claim 11, wherein the optically anisotropic film is disposed in each region corresponding to each pixel in the liquid crystal cell. An optically active compound represented by the general formula (3).

(L ⁴ represents a divalent linking group having 3 or more carbon atoms, Q represents a polymerizable group, and L ⁵ represents a divalent linking group.) A method for producing a biaxial optically anisotropic film having a deformed twisted helical structure,
Applying a composition comprising at least one polymerizable liquid crystal compound and at least one optically active compound racemized by light; and thereafter
Irradiating the composition with polarized light,
The manufacturing method which does not include the process of irradiating non-polarized light before the said polarized light irradiation. A composition for producing a deformed twisted spiral biaxial optically anisotropic film, comprising at least one polymerizable liquid crystal compound and at least one optically active compound racemized by light .

Images