JP5537009B2 - Liquid crystal composition, optically anisotropic film, and retardation plate - Google Patents

Description

  The present invention relates to a liquid crystal composition useful for producing a retardation plate and the like, and an optically anisotropic film and a retardation plate produced using the liquid crystal composition.

Various types of retardation plates using an optical anisotropic film formed using a liquid crystal composition have been proposed as retardation plates used for optical compensation of liquid crystal display devices. In addition, various 1,3,5-substituted discotic liquid crystal compounds have been proposed as liquid crystal compounds used for the production of optically anisotropic films (Patent Documents 1 to 6).
By the way, for the production of the retardation plate, it is necessary to align the molecules of the liquid crystal compound without defects. However, when a 1,3,5-substituted benzene type discotic liquid crystal compound is used, a streak shape is formed in the film. Therefore, improvement of the orientation defect is desired.
JP 2005-122155 A JP 2006-76992 A JP 2006-265283 A JP 2006-316013 A JP 2006-327975 A JP 2007-2220 A

The present invention relates to a liquid crystal composition containing a 1,3,5-substituted benzene type discotic liquid crystal compound, which is optical without causing streak-like orientation defects (or while suppressing the occurrence of streak-like orientation defects). It is an object to provide a liquid crystal composition capable of forming an anisotropic film.
It is another object of the present invention to provide an optically anisotropic film and a retardation plate that are produced using the liquid crystal composition free from (or have few) streak-like alignment defects.

  As a result of intensive studies by the present inventor, when aligning molecules of a 1,3,5-substituted benzene type discotic liquid crystal compound on the surface of the alignment film, a compound capable of reducing the tilt angle at the alignment film interface of the molecule The inventors have found that when alignment is performed in the presence, streaky alignment defects generated in the formed optically anisotropic film can be reduced. As a result of further intensive studies based on this knowledge, the molecules of a 1,3,5-substituted benzene type discotic liquid crystal compound are aligned in the presence of a compound having a disc-like structure other than the 1,3,5-substituted benzene skeleton. As a result, the tilt angle of the alignment film interface was reduced, and as a result, it was found that streak-like alignment defects were less likely to occur in the formed optically anisotropic film, and the present invention was completed.

式中、Ｌ¹はそれぞれ独立に、−Ｏ−、−Ｓ−、−ＮＨ−を表し；Ｒ¹は下記式（Ｒ−ＩＡ）：
式（Ｒ−ＩＡ）
＊−Ｃｙ¹−（Ｌ^1A−Ｃｙ²）_p−Ｌ^2A−（Ｌ^3A）_r−Ｑ^1A
［式（Ｒ−ＩＡ）中、＊はＬ¹に結合する位置を表し；Ｃｙ¹及びＣｙ²はそれぞれ、少なくとも１種類の環状構造を有する二価の連結基を表し；Ｌ^1Aは単結合又は二価の連結基を表し；Ｌ^2Aは単結合又は二価の連結基を表し；Ｌ^3Aは、アルキレン基、置換アルキレン基、アルケニレン基、置換アルケニレン基、アルキニレン基、又は置換アルキニレン基を表し；Ｑ^1Aは重合性基又は水素原子を表し；ｐは０〜２の整数を表し；ｒは０又は１を表す］を表す。 That is, the means for solving the problems are as follows.
[1] Contains at least one 1,3,5-substituted benzene type discotic liquid crystal compound and at least one compound having a discotic structure (excluding 1,3,5-substituted benzene skeleton) as a partial structure. A liquid crystal composition characterized by that.
[2] The liquid crystal composition according to [1], wherein the compound having the discotic structure as a partial structure is a compound represented by the following general formula (TI):

In the formula, each L ¹ independently represents -O-, -S-, -NH-; R ¹ represents the following formula (R-IA):
Formula (R-IA)
^{* -Cy 1 - (L 1A -Cy} 2) p -L 2A - (L 3A) r -Q 1A
[In formula (R-IA), * represents a position bonded to L ¹ ; Cy ¹ and Cy ² each represent a divalent linking group having at least one cyclic structure; L ^1A represents a single bond or L ^2A represents a single bond or a divalent linking group; L ^3A represents an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, or a substituted alkynylene group; Q ^1A represents a polymerizable group or a hydrogen atom; p represents an integer of 0 to 2; and r represents 0 or 1.

一般式（ＤＩ）中、Ｙ¹¹、Ｙ¹²及びＹ¹³は、それぞれ独立にメチン又は窒素原子を表し、Ｒ¹¹、Ｒ¹²及びＲ¹³は、それぞれ独立に下記一般式（ＤＩ−Ａ）、下記一般式（ＤＩ−Ｂ）又は下記一般式（ＤＩ−Ｃ）；

（一般式（ＤＩ−Ａ）中、Ａ¹¹、Ａ¹²、Ａ¹³、Ａ¹⁴、Ａ¹⁵及びＡ¹⁶は、それぞれ独立にメチン又は窒素原子を表し、Ｘ¹は、酸素原子、硫黄原子、メチレン又はイミノを表し、Ｌ¹¹は−Ｏ−、−Ｏ−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−Ｏ−、−Ｓ−、−ＮＨ−、−ＳＯ₂−、−ＣＨ₂−、−ＣＨ＝ＣＨ−又は−Ｃ≡Ｃ−を表し、Ｌ¹²は、−Ｏ−、−Ｓ−、−Ｃ（＝Ｏ）−、−ＳＯ₂−、−ＮＨ−、−ＣＨ₂−、−ＣＨ＝ＣＨ−及び−Ｃ≡Ｃ−ならびにこれらの組み合わせからなる群より選ばれる二価の連結基を表し、上述の基が水素原子を含む基であるときは、該水素原子は置換基で置き換わってもよい。Ｑ¹¹はそれぞれ独立に、重合性基又は水素原子を表す。）

（一般式（ＤＩ−Ｂ）中、Ａ²¹、Ａ²²、Ａ²³、Ａ²⁴、Ａ²⁵及びＡ²⁶は、それぞれ独立にメチン又は窒素原子を表し、Ｘ²は、酸素原子、硫黄原子、メチレン又はイミノを表し、Ｌ²¹は−Ｏ−、−Ｏ−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−Ｏ−、−Ｓ−、−ＮＨ−、−ＳＯ₂−、−ＣＨ₂−、−ＣＨ＝ＣＨ−又は−Ｃ≡Ｃ−を表し、Ｌ²²は、−Ｏ−、−Ｓ−、−Ｃ（＝Ｏ）−、−ＳＯ₂−、−ＮＨ−、−ＣＨ₂−、−ＣＨ＝ＣＨ−及び−Ｃ≡Ｃ−ならびにこれらの組み合わせからなる群より選ばれる二価の連結基を表し、上述の基が水素原子を含む基であるときは、該水素原子は置換基で置き換わってもよい。Ｑ²¹はそれぞれ独立に、重合性基又は水素原子を表す。）

（一般式（ＤＩ−Ｃ）中、Ａ³¹、Ａ³²、Ａ³³、Ａ³⁴、Ａ³⁵及びＡ³⁶は、それぞれ独立にメチン又は窒素原子を表し、Ｘ³は、酸素原子、硫黄原子、メチレン又はイミノを表し、Ｌ³¹は−Ｏ−、−Ｏ−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−Ｏ−、−Ｓ−、−ＮＨ−、−ＳＯ₂−、−ＣＨ₂−、−ＣＨ＝ＣＨ−又は−Ｃ≡Ｃ−を表し、Ｌ³²は、−Ｏ−、−Ｓ−、−Ｃ（＝Ｏ）−、−ＳＯ₂−、−ＮＨ−、−ＣＨ₂−、−ＣＨ＝ＣＨ−及び−Ｃ≡Ｃ−ならびにこれらの組み合わせからなる群より選ばれる二価の連結基を表し、上述の基が水素原子を含む基であるときは、該水素原子は置換基で置き換わってもよい。Ｑ³¹はそれぞれ独立に、重合性基又は水素原子を表す）を表す。 [3] The liquid crystal composition according to [1] or [2], wherein the 1,3,5-substituted benzene type discotic liquid crystal compound is a compound represented by the following general formula (DI):

In the general formula (DI), Y ¹¹ , Y ¹² and Y ¹³ each independently represent a methine or nitrogen atom, and R ¹¹ , R ¹² and R ¹³ are each independently the following general formula (DI-A), General formula (DI-B) or the following general formula (DI-C);

(In the general formula (DI-A), A ¹¹ , A ¹² , A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ each independently represents a methine or nitrogen atom, and X ¹ represents an oxygen atom, a sulfur atom, or methylene. Or L ¹¹ represents —O—, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C—, and L ¹² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH. Represents a divalent linking group selected from the group consisting of ═CH— and —C≡C— and combinations thereof, and when the above group is a group containing a hydrogen atom, the hydrogen atom is replaced by a substituent. Q ¹¹ represents each independently a polymerizable group or a hydrogen atom.)

(In the general formula (DI-B), A ²¹ , A ²² , A ²³ , A ²⁴ , A ²⁵ and A ²⁶ each independently represents a methine or nitrogen atom, and X ² represents an oxygen atom, a sulfur atom, or methylene. Or L ²¹ represents —O—, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C—, and L ²² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH. Represents a divalent linking group selected from the group consisting of ═CH— and —C≡C— and combinations thereof, and when the above group is a group containing a hydrogen atom, the hydrogen atom is replaced by a substituent. Q ²¹ each independently represents a polymerizable group or a hydrogen atom.)

(In the general formula (DI-C), A ³¹ , A ³² , A ³³ , A ³⁴ , A ³⁵ and A ³⁶ each independently represents a methine or nitrogen atom, and X ³ represents an oxygen atom, a sulfur atom, or methylene. Or L ³¹ represents —O—, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C—, and L ³² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH. Represents a divalent linking group selected from the group consisting of ═CH— and —C≡C— and combinations thereof, and when the above group is a group containing a hydrogen atom, the hydrogen atom is replaced by a substituent. Q ³¹ represents each independently a polymerizable group or a hydrogen atom.

[4] An optically anisotropic film formed from the liquid crystal composition according to any one of [1] to [3].
[5] A retardation plate comprising a support and an optically anisotropic layer formed of the liquid crystal composition according to any one of [1] to [3] on the support.
[6] The retardation plate of [5], comprising an alignment film between the support and the optically anisotropic layer, wherein the alignment film contains a partially saponified polyvinyl alcohol derivative.
[7] An optically anisotropic film comprising an alignment step of aligning molecules of a 1,3,5-substituted benzene type discotic liquid crystal compound on the surface of the alignment film, and fixing an alignment state obtained in the alignment step A manufacturing method comprising:
A method for producing an optically anisotropic film, wherein in the alignment step, molecules of a 1,3,5-substituted benzene type discotic liquid crystal compound are aligned at a tilt angle of 1 to 12 ° at an alignment film interface.

According to the present invention, it is possible to suppress streak-like alignment defects that occur when a 1,3,5-substituted benzene type discotic liquid crystal compound is used.
That is, according to the present invention, a liquid crystal composition containing a 1,3,5-substituted benzene-type discotic liquid crystal compound without causing streak-like alignment defects (or suppressing occurrence of streak-like alignment defects). However, a liquid crystal composition capable of forming an optically anisotropic film can be provided.
In addition, according to the present invention, it is possible to provide an optically anisotropic film and a phase difference plate that are produced using the liquid crystal composition that does not have (or has few) streak-like alignment defects.

Hereinafter, the present invention will be described in detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
[Liquid crystal composition]
The liquid crystal composition of the present invention comprises at least one of 1,3,5-substituted benzene type discotic liquid crystal compounds and at least a compound having a discotic structure (excluding a 1,3,5-substituted benzene skeleton) as a partial structure. It is characterized by containing 1 type.
The optically anisotropic film formed from the liquid crystal composition of the present invention has no (or few) streak-like alignment defects. The details of the action mechanism of the present invention are not clear, but the molecules of the 1,3,5-substituted benzene type discotic liquid crystal compound are aligned on the alignment film surface in the presence of a compound having a disk-like structure as a partial structure. It is considered that the tilt angle of the molecules at the alignment film interface is reduced, and as a result, the number of streak-shaped alignment defects generated in the formed optically anisotropic film is reduced.
(Tilt angle on the alignment film side)
In the present invention, the tilt angle refers to the average direction of the normal of the disc surface of a molecule of a 1,3,5-substituted benzene type discotic liquid crystal compound (director of the discotic liquid crystal phase), the normal of the alignment film surface, This is the angle formed by
As a result of detailed investigation of the cause of the generation of streak-like alignment defects generated when a 1,3,5-substituted benzene type discotic liquid crystal compound is used, the streak-like defects are caused by a high tilt angle on the alignment film side. It has been found that it occurs. Specifically, when the tilt angle is 13 ° or more, alignment defects increase. Therefore, in the present invention, the tilt angle of the alignment film interface of the molecules of the 1,3,5-substituted benzene type discotic liquid crystal compound is set to 1-12. It is preferable to use a compound having a disk-like structure as a partial structure that can be reduced to ° (more preferably 3 to 10 °).

(Tilt angle measurement method on the alignment film side)
The tilt angle in the liquid crystal state of the 1,3,5-substituted benzene type discotic liquid crystal compound can be measured using a known method other than the liquid crystal preparation method. For example, the crystal rotation method described on page 239 of “Liquid Crystal Handbook” Maruzen can be suitably used. In this method, first, a liquid crystal composition is injected into a relatively thick cell subjected to anti-parallel rubbing treatment, and the liquid crystal composition is uniformly aligned. Next, between the pair of polarization prisms arranged in crossed Nicols, the liquid crystal cell is placed so that the rubbing direction is diagonal, and this is rotated around an axis parallel to the cell surface and perpendicular to the rubbing, This is a method of calculating the pretilt angle by measuring the transmitted light intensity with respect to this rotation angle using a monochromatic light source such as a laser as incident light. By covering this cell with a heater jacket or the like and controlling the heating temperature, it is possible to measure even a discotic liquid crystal having a liquid crystal temperature range exceeding 100 ° C.

  The cell used for measurement is formed by laminating an alignment film on a transparent support such as glass or polymer film, with a gap control spacer in between, so that it has an anti-parallel rubbing relationship. To do. As Δn of the liquid crystal to be measured is smaller, it is preferable to use a thick cell gap because the measurement accuracy becomes higher. For example, if Δn is as small as 0.05, a relatively thick one of about 100 μm is preferable for accurately measuring the pretilt angle, and if Δn is about 0.15, a thickness of 30 μm is also accurate. It can be measured.

The sample for measurement, that is, the liquid crystal composition is prepared by adding the above-mentioned polymerization inhibitor to the coating solution for forming the retardation plate, stirring, mixing, and heating to the liquid crystal temperature on an evaporator or a hot plate. Vaporize and dry. By this method, the polymerization inhibitor can be uniformly dispersed or dissolved in the liquid crystal composition, so that a sufficient inhibition effect can be exhibited. The addition amount of the polymerization inhibitor is not preferable if the addition amount is too small, because a sufficient polymerization preventing effect cannot be imparted. On the contrary, if the content is too large, the pretilt angle of the polymerizable liquid crystal is affected. Accordingly, there is an optimum range of addition amount, and it is preferably 0.5% by mass to 5.0% by mass with respect to the total mass of the liquid crystal composition (solid content in the case of a coating liquid), 1.0 It is more preferable that it is mass%-3.0 mass%.
When the liquid crystal composition of the present invention contains a material that is unevenly distributed on the air interface side after coating, such as an air interface side alignment agent or a surface tension adjuster, the material segregates on the alignment film side of the cell and is inherently In order to affect the pretilt angle, a sample is prepared by mixing a polymerization inhibitor into the composition excluding the pretilt angle.
In the case of a liquid crystal composition containing a polymerization initiator, polymerization may proceed by heating depending on the type and amount of the initiator. In that case, the measurement can be carried out by preparing a composition with the initiator removed or reduced.

  Next, since fine bubbles are mixed in the liquid crystal obtained by evaporating and drying the solvent, this is removed by heating or reduced pressure, and the liquid crystal is injected into the capillary while heating the cell. The higher the injection temperature, the faster the injection speed. However, since the thermal polymerization is facilitated, the range of 100 ° C. to 150 ° C. is preferable. In addition, since the tilt angle value may be affected by the phase state during injection, the injection is preferably performed in the liquid phase state. In the case of a sample having a liquid crystal upper limit temperature of 150 ° C. or more, measurement is performed after injecting in a nematic liquid crystal phase to avoid polymerization and holding the temperature until the tilt angle does not change with time.

Hereinafter, materials used for the liquid crystal composition of the present invention will be described in detail.
(1,3,5-substituted benzene type discotic liquid crystal compound)
The 1,3,5-substituted benzene type discotic liquid crystal compound used in the present invention is not particularly limited, and any discotic liquid crystal compound having a benzene skeleton substituted at the 1,3,5-position as a partial structure. Can be used. Specifically, compounds represented by general formula (I) and general formula (II) described in JP-A-2005-122155; general formula (DI) and general formula described in JP-A-2006-76992 Compound represented by (DII); Compound represented by general formula (DI) described in JP-A-2006-265283; Compound represented by general formula (DI) described in JP-A-2006-316013 A compound represented by the general formula (DI) described in JP 2006-327975 A; and a compound represented by the general formula (DI) and general formula (DII) described in JP 2007-2220 A; Etc. are exemplified. Among these, a compound represented by the following general formula (DI) described in JP-A-2007-2220 is particularly preferable.

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

When Y ¹¹ , Y ¹² and Y ¹³ are methine, the hydrogen atom of methine may be replaced with a substituent. Examples of the substituent that methine may have 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 can be mentioned as a preferred example. Among these substituents, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, a halogen atom and a cyano group are more preferable, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and a carbon number A 2-12 alkoxycarbonyl group, a C2-C12 acyloxy group, a halogen atom, and a cyano group are more preferable.
Y ¹¹ , Y ¹² and Y ¹³ are more preferably methine, and methine is more preferably unsubstituted.

R ¹¹ , R ¹² and R ¹³ each independently represent the following general formula (DI-A), the following general formula (DI-B) or the following general formula (DI-C). In order to reduce the wavelength dispersion, the general formula (DI-A) or the general formula (DI-C) is preferable, and the general formula (DI-A) is more preferable. R ¹¹ , R ¹² and R ¹³ are preferably R ¹¹ = R ¹² = R ¹³ .

In the general formula (DI-A), A ¹¹ , A ¹² , A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ each independently represent a methine or nitrogen atom.
At least one of A ¹¹ and A ¹² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
Of A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ , at least three of them are preferably methine, more preferably all methine. Furthermore, methine is preferably unsubstituted.
Examples of substituents when A ¹¹ , A ¹² , A ¹³ , A ¹⁴ , A ¹⁵ or A ¹⁶ is methine include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), cyano groups, nitro groups An alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, and 1 carbon atom -16 alkoxy group, C2-C16 acyl group, C1-C16 alkylthio group, C2-C16 acyloxy group, C2-C16 alkoxycarbonyl group, carbamoyl group, An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ¹ represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

In the general formula (DI-B), A ²¹ , A ²² , A ²³ , A ²⁴ , A ²⁵ and A ²⁶ each independently represents a methine or nitrogen atom.
At least one of A ²¹ and A ²² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
Of A ²³ , A ²⁴ , A ²⁵ and A ²⁶ , at least three of them are preferably methine, more preferably all methine.
Examples of substituents when A ²¹ , A ²² , A ²³ , A ²⁴ , A ²⁵ or A ²⁶ is methine include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), cyano groups, nitro groups An alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, and 1 carbon atom -16 alkoxy group, C2-C16 acyl group, C1-C16 alkylthio group, C2-C16 acyloxy group, C2-C16 alkoxycarbonyl group, carbamoyl group, An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ² represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

In the general formula (DI-C), A ³¹ , A ³² , A ³³ , A ³⁴ , A ³⁵ and A ³⁶ each independently represent a methine or nitrogen atom.
At least one of A ³¹ and A ³² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
At least three of A ³³ , A ³⁴ , A ³⁵ and A ³⁶ are preferably methine, more preferably methine.
When A ³¹ , A ³² , A ³³ , A ³⁴ , A ³⁵ or A ³⁶ is methine, the methine 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 2 to 16 carbon atoms, carbon An alkynyl group having 2 to 16 atoms, an alkyl group substituted with a halogen 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 1 to 16 carbon atoms An alkylthio 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. included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ³ represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

L ^{11 in} the general formula (DI-A), L ^{21 in} the general formula (DI-B), and L ³¹ in the general formula (DI-C) are each independently —O—, —O—CO—. , —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C—. Preferably, -O -, - O-CO -, - CO-O -, - O-CO-O -, - CH 2 -, - CH = CH -, - it is C≡C-, more preferably, —O—, —O—CO—, —CO—O—, —O—CO—O—, —CH ₂ —. When the above group is a group containing a hydrogen atom, the hydrogen atom may be replaced with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy 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 Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred.

L ^{12 in} the general formula (DI-A), L ^{22 in} the general formula (DI-B), and L ³² in the general formula (DI-C) are each independently -O-, -S-,- It represents a divalent linking group selected from the group consisting of C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. Here, the hydrogen atoms of —NH—, —CH ₂ —, and —CH═CH— may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy 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 Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred.

L ¹² , L ²² and L ³² are each independently selected from the group consisting of —O—, —C (═O) —, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. It is preferable to be selected.

L ¹² , L ²² and L ³² each independently preferably have 1 to 20 carbon atoms, and more preferably 2 to 14 carbon atoms. The number of carbon atoms is preferably 2 to 14, more preferably 1 to 16 —CH ₂ —, and still more preferably ₂ to 12 —CH ₂ —.

L ¹² , L ²² and L ³² are each independently —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and It is preferably a divalent linking group selected from the group consisting of —C≡C— and combinations thereof, and having 1 to 20 carbon atoms. Incidentally carbon number is preferably 2 to 14 carbon atoms, -CH ₂ - and more preferably has 1 to 16, -CH ₂ - further preferred that the having 2 to 12.

Q ^{11 in} the general formula (DI-A), Q ^{21 in} the general formula (DI-B), and Q ³¹ in the general formula (DI-C) each independently represent a polymerizable group or a hydrogen atom. When the compound of the present invention is used for an optical film or the like that preferably has a phase difference that does not change due to heat, such as an optical compensation film, Q ¹¹ , Q ²¹ , and Q ³¹ are preferably a polymerizable group. . The polymerization reaction is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. That is, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

  Furthermore, the polymerizable group is particularly preferably a functional group capable of addition polymerization reaction. Such a polymerizable group is preferably a polymerizable ethylenically unsaturated group or a ring-opening polymerizable group.

  Examples of the polymerizable ethylenically unsaturated group include the following formulas (M-1) to (M-6).

In formulas (M-3) and (M-4), R represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.
Among the formulas (M-1) to (M-6), (M-1) or (M-2) is preferable, and (M-1) is more preferable.

  The ring-opening polymerizable group is preferably a cyclic ether group, more preferably an epoxy group or oxetanyl group, and most preferably an epoxy group.

  Although the specific example of a compound represented by general formula (DI) below is shown, this invention is not limited to these.

(Compound having a disk-like structure as a partial structure)
The liquid crystal composition of the present invention contains at least one compound having a discotic structure as a partial structure (hereinafter referred to as “discotic compound”). The discotic compound is a compound capable of reducing the tilt angle at the alignment film interface of the molecules of the 1,3,5-substituted benzene type discotic liquid crystal compound. The disc-like structure is not particularly limited as long as it is other than the 1,3,5-substituted benzene skeleton. The discotic compound may be a liquid crystal compound or a non-liquid crystal compound. It is preferable to use a discotic liquid crystalline compound or a compound having a discoid shape having a discotic liquid crystal core.

Preferable examples of the discotic compound include compounds represented by the following general formula (D).
Formula (D) D (-LQ) _n
In the formula, D is a discotic core, L is a divalent linking group, and Q is a polymerizable group. Moreover, n is an integer of 3-12. Examples of the disk-shaped core (D) of the above formula are shown below. In each of the following examples, LQ (or QL) means a combination of a divalent linking group (L) and a polymerizable group (Q). The structural formulas of specific examples (D1 to D16) of the general formula (D) are shown below.

  L in the general formula (D) is a divalent group selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —C (═O) —, —NH—, —O—, —S—, and combinations thereof. The linking group is preferably. L is a group in which at least two divalent groups selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —C (═O) —, —NH—, —O—, and —S— are combined. More preferably it is. L is most preferably a group obtained by combining at least two divalent groups selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, -C (= O)-and -O-. The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The number of carbon atoms in the arylene group is preferably 6-10. The alkylene group, alkenylene group and arylene group may have a substituent (eg, alkyl group, halogen atom, cyano group, alkoxy group, acyloxy group).

  Examples of the divalent linking group (L) are shown below. In each formula, the left side is bonded to the discotic core (D), and the right side is bonded to the polymerizable group (Q). AL represents an alkylene group or an alkenylene group, and AR represents an arylene group.

L1: -AL-C (= O) -O-AL-
L2: -AL-C (= O) -O-AL-O-
L3: -AL-C (= O) -O-AL-O-AL-
L4: -AL-C (= O) -O-AL-OC (= O)-
L5: -C (= O) -AR-O-AL-
L6: -C (= O) -AR-O-AL-O-
L7: -C (= O) -AR-O-AL-OC (= O)-
L8: -C (= O) -NH-AL-
L9: -NH-AL-O-
L10: -NH-AL-OC (= O)-
L11: -O-AL-
L12: -O-AL-O-
L13: -O-AL-OC (= O)-

L14: -O-AL-OC (= O) -NH-AL-
L15: -O-AL-S-AL-
L16: -OC (= O) -AL-AR-O-AL-OC (= O)-
L17: -OC (= O) -AR-O-AL-C (= O)-
L18: -OC (= O) -AR-O-AL-OC (= O)-
L19: -OC (= O) -AR-O-AL-O-AL-OC (= O)-
L20: -OC (= O) -AR-O-AL-O-AL-O-AL-OC (= O)-
L21: -S-AL-
L22: -S-AL-O-
L23: -S-AL-OC (= O)-
L24: -S-AL-S-AL-
L25: -S-AR-AL-

The polymerizable group (Q) of the general formula (D) is not particularly limited. When the liquid crystal composition of the present invention is polymerized, it can be determined according to the type of polymerization reaction.
Preferred specific examples of the polymerizable group (Q) are the same as those described in the liquid crystalline composition R that exhibits a liquid crystal phase satisfying the formula (I), and more preferable polymerizable groups (Q) are also represented by the formula (I). This is the same as the liquid crystalline composition R that exhibits a liquid crystal phase satisfying

  In general formula (D), n is an integer of 3-12. A specific number is determined according to the type of the disk-shaped core (D). n is particularly preferably an integer of 3 to 6. In addition, although the combination of several L and Q may differ, it is preferable that it is the same.

  Two or more kinds of compounds may be used in combination as the compound having a disc shape. For example, a molecule having a polymerizable group (Q) and a molecule not having it may be used in combination.

  The non-polymerizable compound is preferably a compound in which the polymerizable group (Q) of the above-described compound is changed to a hydrogen atom or an alkyl group. That is, the non-polymerizable compound is preferably a compound represented by the following formula.

D (-LR) _n

  In the formula, D is a discotic core, L is a divalent linking group, and R is a hydrogen atom or an alkyl group. Moreover, n is an integer of 3-12. The example of the discotic core (D) of the above formula is the same as the example of the polymerizable compound except that LQ (or QL) is changed to LR (or RL). Moreover, the example of a bivalent coupling group (L) is the same as the example of the said polymeric compound. The alkyl group for R preferably has 1 to 40 carbon atoms, and more preferably 1 to 30 carbon atoms. A chain alkyl group is preferred to a cyclic alkyl group, and a linear alkyl group is preferred to a branched chain alkyl group. R is particularly preferably a hydrogen atom or a linear alkyl group having 1 to 30 carbon atoms.

Among the specific examples D1 to D16, D4 and D16 are particularly preferable as the core part from the viewpoint of no coloring and easy availability of the compound.
Moreover, as a bivalent coupling group (L), among the said specific examples L1-L25, L1-L8, L10, L13, L16-L20, and L23 which have an ester bond are preferable. When the core part is D4, L18 is particularly preferable as the divalent linking group (L).
The reason why the ester bond is preferable is not clear, but the following reasons are conceivable. In many cases, the dipole moment of the carbonyl group (C═O) of the ester bond does not exist in the disc surface of the discotic compound, but often faces out of the plane. For example, when a polyvinyl alcohol polymer is used as the alignment film as described later, the surface of the polyvinyl alcohol has many acetyl groups and hydroxyl groups. It is expected that an additive having an ester group has a strong interaction (dipole-dipole interaction as well as hydrogen bonding) with respect to such an alignment film surface. Further, it is expected that the additive is adsorbed in parallel with the disk surface on the alignment film interface because the additive has a disk shape and has a carbonyl group out of the plane. In such a state, the excluded volume effect of the discotic compound works, and as a result, the 1,3,5-substituted benzene type discotic liquid crystal compound also tends to have the alignment film interface and the disk surface parallel (tilt). Is considered to be reduced).

  Among the above exemplified compounds, D16, which can be constructed in a short process and is highly effective when added in a small amount, is preferable. Among the discotic compounds represented by D16, compounds represented by the following general formula (TI) are particularly preferred.

In general formula (TI), L < ¹ > represents -O-, -S-, -NH- each independently. L ¹ is particularly preferably —NH—.
In the general formula (TI), R ¹ represents the following formula (R-IA).
Formula (R-IA)
^{* -Cy 1 - (L 1A -Cy} 2) p -L 2A - (L 3A) r -Q 1A
In formula (R-IA), * represents a position bonded to L ¹ .

In the above formula, Cy ¹ and Cy ² each represent a divalent linking group having at least one cyclic structure. The ring in the divalent cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring. Further preferred. The ring in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. Further, the ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. 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, a pyrimidine ring, a thiophene ring, a 1,3-dioxane ring, and a 1,3-dithiane ring.

  As the cyclic group having a benzene ring, 1,4-phenylene is preferable. As the cyclic group having a naphthalene ring, naphthalene-1,5-diyl and naphthalene-2,6-diyl are preferable. The cyclic group having a cyclohexane ring is preferably 1,4-cyclohexylene. As the cyclic group having a pyridine ring, pyridine-2,5-diyl is preferable. The cyclic group having a pyrimidine ring is preferably pyrimidine-2,5-diyl. As the cyclic group having a thiophene ring, thiophene-2,5-diyl is preferable. As the cyclic group having a 1,3-dioxane ring, 1,3-dioxylene-2,5-diyl is preferable. As the skeleton having a 1,3-dithiane ring, 1,3-dithianylene-2,5-diyl is preferable.

Cy ¹ and Cy ² are respectively 1,4-phenylene, 1,4-cyclohexylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, and 1,3-dioxylene-2,5-diyl. 1,4-phenylene, 1,4-cyclohexylene, or 1,3-dioxylene-2,5-diyl is more preferable, and 1,4-phenylene is particularly preferable.

Cy ¹ and Cy ² may each have a substituent, and the substituent includes a halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), and an alkyl group having 1 to 8 carbon atoms. , An alkyloxy group having 1 to 8 carbon atoms, an acyl group having 2 to 8 carbon atoms, an acyloxy group having 2 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a nitro group, or a cyano group. Preferably. In particular, a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkyloxy group having 1 to 3 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, and 2 carbon atoms. -4 alkoxycarbonyl groups or cyano groups are preferred.

L ^1A is a single bond or a divalent linking group. When L _1A is a divalent linking group, —O—, —S—, —C (═O) —, —NR ⁷ —, —CH ₂ —, —CH═CH—, —C≡C—, and It is preferably a divalent linking group selected from the group consisting of those combinations. R ⁷ is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and preferably a methyl group, an ethyl group, or a hydrogen atom. More preferably, it is a hydrogen atom.

L ^1A represents a single bond, and, * - O-CO -, * - CO-O -, * - CH 2 -CH 2 -, * - O-CH 2 -, * - CH 2 -O -, * - CO —CH ₂ —CH ₂ —, * —CH═CH—, * —C≡C— (wherein * represents * in the formula (R—IA)) is preferable, and in particular, a single bond, * —O— CO- is preferred.

L ^2A is a single bond or a divalent linking group. When L ^2A is a divalent linking group, it may be a divalent linking group selected from the group consisting of —O—, —S—, —C (═O) —, —NR ⁷ —, and combinations thereof. preferable. R ⁷ is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and preferably a methyl group, an ethyl group, or a hydrogen atom. More preferably, it is a hydrogen atom.

L ^2A represents a single bond, and * —O—, * —O—CO—, * —CO—O—, * —O—CO—O—, * —CO—, * —S—, * —NR ⁷ —. (Wherein * represents a position linked to a divalent cyclic group in the general formula (R-IA)), and in particular, * —O—CO—, * —CO—O—, * —O. -CO-O- is preferred.

L ^3A represents an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, or a substituted alkynylene group. Among these, an alkylene group, a substituted alkylene group, an alkenylene group, or a substituted alkenylene group is preferable, and an alkylene group or an alkenylene group is more preferable.
The alkylene group may have a branch. Moreover, —CH ₂ — in the alkylene group may be replaced by, for example, —O— or —S—. The alkylene group preferably has 1 to 16 carbon atoms, more preferably 2 to 14 carbon atoms, and most preferably 2 to 12 carbon atoms. The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include an alkyl group and a halogen atom.

The alkenylene group may have a substituted or unsubstituted alkylene group in the main chain, or may have a branch. Also during alkenylene group -CH ₂ - when there is, -CH ₂ -, for example -O -, - may be replaced by S-. The alkenylene group preferably has 2 to 16 carbon atoms, more preferably 2 to 14 carbon atoms, and most preferably 2 to 12 carbon atoms. The alkenylene part of the substituted alkenylene group is the same as the above alkenylene group. Examples of the substituent include an alkyl group and a halogen atom.

The alkynylene group may have a substituted or unsubstituted alkylene group in the main chain, or may have a branch. Also during alkynylene group -CH ₂ - when there is, -CH ₂ -, for example -O -, - may be replaced by S-. The alkynylene group preferably has 2 to 16 carbon atoms, more preferably 1 to 14 carbon atoms, and most preferably 1 to 12 carbon atoms. The alkynylene part of the substituted alkynylene group is the same as the above alkynylene group. Examples of the substituent include an alkyl group and a halogen atom.

Specific examples of L ^3A include methylene, ethylene, trimethylene, tetramethylene, 1-methyl-tetramethylene, pentamethylene, hexamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, 2-butenylene and 2- Examples include butynylene.

L ^3A is preferably a substituted or unsubstituted alkylene group having 1 to 16 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 16 carbon atoms, or a substituted or unsubstituted alkynylene group having 2 to 16 carbon atoms, A substituted or unsubstituted alkylene group having 1 to 12 carbon atoms is preferred. As the substituent of the chain group, an alkyl group having 1 to 5 carbon atoms or a halogen atom is preferable. Even more preferably, it is an unsubstituted alkylene group having 1 to 12 carbon atoms.

Q ^1A represents a polymerizable group or a hydrogen atom. Examples of polymerizable groups are shown below.

Among the above, q1 to q10 are preferable, and q1 to q8 are more preferable.
Furthermore, the polymerizable group is particularly preferably a functional group capable of addition polymerization reaction. Such a polymerizable group is preferably a polymerizable ethylenically unsaturated group or a ring-opening polymerizable group.

  Examples of the polymerizable ethylenically unsaturated group include the following formulas (M-1) to (M-6).

In 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 above (M-1) to (M-6), (M-1) or (M-2) is preferable, and (M-1) is more preferable.

  The ring-opening polymerizable group is preferably a cyclic ether group, and more preferably an epoxy group or an oxetanyl group, and most preferably an epoxy group.

  p represents an integer of 0 to 2. Particularly preferred is 0 or 1. r represents 0 or 1;

  Although the specific example of the discotic compound which can be used for this invention below is shown, it is not limited to these.

  The ratio of the 1,3,5-substituted benzene type discotic liquid crystal compound and the discotic compound in the liquid crystal composition of the present invention is not particularly limited, and the preferred range varies depending on the use and the structure of the compound used. . In order to obtain the effect of adding a discotic liquid crystal compound without impairing the orientation of the 1,3,5 substituted benzene type discotic liquid crystal compound, generally, The mass ratio to the discotic compound is preferably 99.5: 0.5 to 60:40, more preferably 97: 3 to 80:20.

(Other additives)
The liquid crystal composition of the present invention may contain other additives as necessary together with the 1,3,5-substituted benzene type discotic liquid crystal compound and the discotic compound. Examples of the additive include an air interface alignment controller, a leveling agent, a polymerization initiator, a polymerizable monomer, and the like which will be described later.

-Air interface alignment control agent The liquid crystal composition of this invention may contain the air interface alignment control agent. The air interface alignment control agent controls the alignment of the molecules of the liquid crystal compound at the air interface. For example, it is preferable to add an air interface alignment control agent for homeotropic alignment or hybrid alignment of molecules of a 1,3,5-substituted benzene type discotic liquid crystalline compound. Examples of such additives include polymer compounds described in paragraphs [0015] to [0049] of JP-A-2004-46038, paragraph No. [0020] of JP-A-2004-188333. ] To [0100], a maleimide group-containing polymer compound described in paragraphs [0019] to [0057] of Japanese Patent Application No. 2004-3803, and Japanese Patent Application No. 2003-295212. The fluorine-containing compounds described in paragraph Nos. [0040] to [0069], the fluorine-containing compounds described in paragraph Nos. [0011] to [0031] in the specification of Japanese Patent Application No. 2003-330303, and the specification of Japanese Patent Application No. 2002-212100 Excluded volume group-containing compounds described in paragraphs [0031] to [0075] in the book can be mentioned. Preferred examples of the tilt angle control agent include (1) to (15) in JP-A-2002-37777, (3) to (22) in JP-A-2002-38158, P-4, P6-P12, P15-P40 in the specification of 2004-46038, P1-P5, P14-P18, P31-P40, P61-P70 in the specification of Japanese Patent Application No. 2004-188333, Japanese Patent Application P6 to P21 in the specification of 2004-3803, I-1 to I-38, I-43 to I-66 in the specification of Japanese Patent Application No. 2003-295212, and Japanese Patent Application No. 2003-330303 I-1 to I-45, and Ib-3 to Ib-10 in Japanese Patent Application No. 2002-212100.

  The addition amount of the alignment control additive on the air interface side is preferably 0.001% by mass to 20% by mass, and 0.01% by mass to 10% by mass with respect to the total mass of the liquid crystal composition of the present invention. More preferably, 0.1 mass%-5 mass% are still more preferable.

-Leveling agent A leveling agent may be added to the liquid crystal composition of the present invention. When the composition is prepared as a coating liquid and coated to form an optically anisotropic film or the like, it is preferably added. As the leveling agent, a polymer compound is generally used. The polymer used as the leveling agent is not particularly limited as long as it does not change the inclination angle of the molecules of the liquid crystal compound or significantly disturb the alignment.
Examples of polymers that can be used as the leveling agent are described in JP-A-8-95030, and particularly preferred specific polymer examples include cellulose esters. Examples of cellulose esters include cellulose acetate, cellulose acetate propionate, hydroxypropyl cellulose, and cellulose acetate butyrate.
The amount of the leveling agent added is generally preferably in the range of 0.1 to 10% by mass and preferably in the range of 0.1 to 8% by mass with respect to the total mass of the liquid crystal composition of the present invention. More preferably, it is still more preferably in the range of 0.1 to 5% by mass.

Surfactant The liquid crystal composition of the present invention may contain a surfactant. Examples of the surfactant include conventionally known compounds, and fluorine compounds are particularly preferable. Specifically, for example, compounds described in paragraph Nos. [0028] to [0056] in JP-A No. 2001-330725 and compounds described in paragraph Nos. [0100] to [0118] in JP-A No. 2005-179636 are described. Can be mentioned. In general, the surfactant is preferably 0.005 to 8% by mass (preferably 0.05 to 2.5% by mass) based on the 1,3,5-substituted benzene type discotic compound.

-Polymerization initiator It is preferable that the liquid-crystal composition of this invention is curable, and it is preferable to contain the polymerization initiator for that purpose. The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator, but it contains a photopolymerization initiator and is prepared as a composition that undergoes reaction upon light irradiation and cures. 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 substitution Aromatic 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), a combination of triarylimidazole dimer and p-aminophenyl ketone ( U.S. Pat. No. 3,549,367), acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850), oxadiazole compounds (described in U.S. Pat. No. 4,221,970), etc. Can be mentioned.
The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass and more preferably 0.5 to 5% by mass of the liquid crystal composition of the present invention (in the case of a coating liquid, solid content). preferable.

-Polymerizable monomer A polymerizable monomer may be added to the liquid crystal composition of the present invention. The polymerizable monomer that can be used in the present invention is not particularly limited as long as it is compatible with the 1,3,5-substituted benzene-type discotic liquid crystal compound and does not significantly inhibit alignment. Among these, compounds having a polymerization active ethylenically unsaturated group such as a vinyl group, a vinyloxy group, an acryloyl group, and a methacryloyl group are preferably used. The addition amount of the polymerizable monomer is preferably in the range of 0.5 to 50% by mass and more preferably in the range of 1 to 30% by mass with respect to the discotic liquid crystal compound. In addition, it is particularly preferable to use a monomer having two or more reactive functional groups because an effect of improving the adhesion between the alignment film and the optically anisotropic layer can be expected.

-Coating solvent You may prepare the liquid-crystal composition of this invention as a coating liquid. As the solvent used for the preparation, an organic solvent is preferably used. Examples of organic solvents include amides (eg N, N-dimethylformamide), sulfoxides (eg dimethyl sulfoxide), heterocyclic compounds (eg pyridine), hydrocarbons (eg toluene, hexane), alkyl halides (eg , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides, esters and ketones are preferred. These may use 2 or more types of organic solvents together.

[Optically anisotropic film]
Next, the optically anisotropic film of the present invention produced using the liquid crystal composition of the present invention will be described.
The optically anisotropic film of the present invention is formed from the liquid crystal composition of the present invention. For example, the liquid crystal composition of the present invention is prepared as a coating liquid, the coating liquid is applied to the surface of the alignment film, and the molecules of the 1,3,5-substituted benzene type discotic liquid crystal compound are aligned on the alignment film. Then, the alignment state can be fixed.

  The coating liquid can be applied by a known method (for example, spin coating method, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

The liquid crystal composition of the present invention is preferably applied to the alignment film surface. The alignment film is formed by rubbing the surface of an organic compound (preferably polymer) film, oblique deposition of an inorganic compound, formation of a layer having a microgroove, or an organic compound (Langmuir-Blodgett method (LB film)). For example, it can be provided by means such as accumulation of ω-tricosanoic acid or methyl stearylate. Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.
An alignment film formed by rubbing treatment or light irradiation is preferably used, and an alignment film formed by polymer rubbing treatment is more preferable. The rubbing treatment can be generally performed by rubbing the surface of the polymer layer in a certain direction with paper or cloth. The thickness of the alignment film is preferably 0.01 to 10 μm, and more preferably 0.05 to 3 μm.

As a material used for the alignment film, a polyimide polymer or a polyvinyl alcohol polymer is generally used. A polyvinyl alcohol polymer that can be applied with an aqueous solvent that does not attack the polymer film is preferred as the alignment film material because it covers the formation on the polymer film.
Among the polyvinyl alcohol polymers, a partially saponified polyvinyl alcohol polymer having high solubility in water is particularly preferable. The saponification degree is preferably 97% to 70%, and particularly preferably 91% to 85%. As a polymerization degree, 100-3000 are preferable, and 200-1000 are especially preferable.
In particular, those in which the hydroxyl group of partially saponified polyvinyl alcohol is substituted with a group having vinyl, oxiranyl, or aziridinyl are preferable. As a substitution degree of such a substituent, 0.2 to 10% is preferable, and 0.5 to 3.0 is particularly preferable. Specific examples of such polymers are described in JP-A-9-152509.

When a desired alignment state is obtained on the alignment film, the alignment state is fixed by polymerization. It is preferable to irradiate with light for the progress of polymerization, and it is preferable to use ultraviolet rays. The irradiation energy is preferably 10mJ~50J / cm ^2, further preferably 50mJ~800mJ / cm ^2. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. Further, since the oxygen concentration in the atmosphere is related to the degree of polymerization, when the desired degree of polymerization is not reached in the air, it is preferable to reduce the oxygen concentration by a method such as nitrogen substitution. A preferable oxygen concentration is preferably 10% or less, more preferably 7% or less, and still more preferably 3% or less.

There is no particular limitation on the alignment state of the liquid crystal composition in the optically anisotropic film. As an example, a mode in which homeotropic orientation or hybrid orientation is fixed may be mentioned.
The state in which the orientation state is fixed is a state in which the orientation is maintained, which is the most typical and preferred embodiment, but is not limited thereto, for example, usually 0 ° C. to 50 ° C., more severe conditions Below, in the temperature range of −30 ° C. to 70 ° C., the fixed liquid crystal composition has no fluidity, and does not cause a change in the alignment form due to an external field or an external force. This includes the state in which it can be kept stable. When the alignment state is finally fixed and an optically anisotropic film is formed, the liquid crystal composition of the present invention no longer needs to exhibit liquid crystallinity. For example, when a compound having a polymerizable group is used as the liquid crystal compound, polymerization or crosslinking reaction proceeds to increase the molecular weight, and as a result, liquid crystallinity may be lost.

  The thickness of the formed optically anisotropic film is not particularly limited, but is generally preferably 0.2 to 10.0 μm, and more preferably 0.4 to 4.0 μm.

[Phase difference plate]
Next, a retardation plate having the optically anisotropic film of the present invention as an optically anisotropic layer will be described.
The retardation plate of the present invention has an optically anisotropic layer formed from the liquid crystal composition of the present invention on a support. An alignment film may be provided between the support and the optically anisotropic layer.

(Support)
The retardation plate of the present invention has a support that supports the optically anisotropic layer. The support is not particularly limited as long as it is mainly optically isotropic and has a light transmittance of 80% or more, but a polymer film or glass is preferable.
Specific examples of the polymer include cellulose acylates (for example, cellulose diacetate and cellulose triacetate), norbornene-based polymers, poly (meth) acrylate ester films, etc., and many commercially available polymers are preferably used. It is possible. Among these, cellulose esters are preferable from the viewpoint of optical performance, and lower fatty acid esters of cellulose are more preferable. The lower fatty acid is a fatty acid having 6 or less carbon atoms, and the number of carbon atoms is preferably 2 (cellulose acetate), 3 (cellulose propionate) or 4 (cellulose butyrate). Cellulose triacetate is particularly preferred. Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate may be used. Moreover, even if it is a conventionally known polymer such as polycarbonate or polysulfone that easily develops birefringence, a polymer whose expression is lowered by modification of molecules described in International Publication WO00 / 26705 can be used.

Hereinafter, cellulose acylate (particularly, cellulose triacetate) that is preferably used as the support will be described in detail.
As the cellulose acylate, it is preferable to use cellulose acetate having an acetylation degree of 55.0 to 62.5%. In particular, the acetylation degree is preferably 57.0 to 62.0%. The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose. The degree of acetylation follows the measurement and calculation of the degree of acetylation in ASTM: D-817-91 (test method for cellulose acetate and the like). The viscosity average polymerization degree (DP) of the cellulose ester is preferably 250 or more, and more preferably 290 or more. The cellulose ester used in the present invention preferably has a narrow molecular weight distribution of Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. The specific value of Mw / Mn is preferably 1.0 to 1.7, more preferably 1.3 to 1.65, and more preferably 1.4 to 1.6. Further preferred.

  In cellulose acylate, the hydroxyl groups at the 2nd, 3rd and 6th positions of cellulose are not evenly distributed by 1/3 of the total substitution degree, and the substitution degree of the 6th hydroxyl group tends to be small. It is preferable that the substitution degree of the 6-position hydroxyl group of cellulose is larger than the 2-position and 3-position. The 6-position hydroxyl group is preferably substituted with 30 to 40% acyl group, more preferably 31 to 40%, particularly preferably 32 to 40% with respect to the total degree of substitution. The substitution degree at the 6-position is preferably 0.88 or more. The 6-position hydroxyl group may be substituted with an acyl group having 3 or more carbon atoms in addition to the acetyl group (eg, propionyl group, butyryl group, valeroyl group, benzoyl group, acryloyl group). The degree of substitution at each position can be determined by NMR. Cellulose esters having a high degree of substitution at the 6-position hydroxyl group are described in Synthesis Example 1 described in Paragraph Nos. 0043 to 0044 of JP-A No. 11-5851, Synthetic Example 2 described in Paragraph Nos. 0048 to 0049, and Paragraph Nos. 0051 to 0052. It can be synthesized with reference to the method of Synthesis Example 3 described.

A polymer film used as a support, particularly a cellulose acylate film, may contain an aromatic compound having at least two aromatic rings as a retardation increasing agent in order to adjust the retardation. When such a retardation increasing agent is used, the retardation increasing agent is preferably used in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of cellulose acylate, and 0.05 to 15 parts by mass. More preferably, it is used in the range of 0.1 to 10 parts by mass. Two or more aromatic compounds may be used in combination.
The aromatic ring of the aromatic compound includes an aromatic hetero ring in addition to the aromatic hydrocarbon ring.

The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).
The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable.

  As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable, More preferred are a benzene ring and a 1,3,5-triazine ring. It is particularly preferred that the aromatic compound has at least one 1,3,5-triazine ring.

  Examples of the aromatic heterocycle include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine Rings, pyridazine rings, pyrimidine rings, pyrazine rings and 1,3,5-triazine rings are included.

  The number of aromatic rings contained in the aromatic compound is preferably 2 to 20, more preferably 2 to 12, further preferably 2 to 8, and most preferably 2 to 6. . The bonding relationship between two aromatic rings can be classified into (a) when forming a condensed ring, (b) when directly connecting with a single bond, and (c) when connecting via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c). Such retardation increasing agents are described in International Publication WO01 / 88574A1 Pamphlet, International Publication WO00 / 2619A1 Pamphlet, JP 2000-1111914 A, JP 2000-275434 A, JP 2002-363343 A, and the like. ing.

The cellulose acylate film is preferably produced by a solvent cast method from the prepared cellulose acylate solution (dope). The above-mentioned retardation increasing agent may be added to the dope.
The dope is cast on a drum or band and the solvent is evaporated to form a film. The concentration of the dope before casting is preferably adjusted so that the solid content is 18 to 35% by mass. The surface of the drum or band is preferably finished in a mirror state. The casting and drying methods in the solvent casting method are described in U.S. Pat. No. 736892, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, No. 60-203430, and No. 62-115035.

  The dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less. After casting, it is preferable to dry it by applying air for 2 seconds or more. The obtained film can be peeled off from the drum or band, and further dried by high-temperature air whose temperature is successively changed from 100 to 160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting.

It is also possible to form a film by casting two or more layers of dope using the prepared cellulose acylate solution (dope). The dope is cast on a drum or band and the solvent is evaporated to form a film. The dope before casting is preferably adjusted in concentration so that the solid content is 10 to 40%. The surface of the drum or band is preferably finished in a mirror state.
When casting a plurality of cellulose acylate solutions, a solution containing cellulose acylate is cast from a plurality of casting openings provided at intervals in the traveling direction of the support, and the film is laminated while laminating them. It may be produced. For example, the methods described in JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be used. Alternatively, the cellulose acylate solution may be cast from two casting ports to form a film. For example, the methods described in JP-B-60-27562, JP-A-61-94724, JP-A-61-104813, JP-A-61-158413, and JP-A-6-134933 are used. Can do. Also, a cellulose acetate film casting method in which a flow of a high-viscosity cellulose acetate solution is wrapped in a low-viscosity cellulose acetate solution and the high-viscosity and low-viscosity cellulose acetate solutions are simultaneously extruded as described in JP-A-56-162617. A method may be used.

  The retardation of the cellulose acylate film can be further adjusted by a stretching treatment. The draw ratio is preferably in the range of 0 to 100%. When stretching the cellulose acylate film used in the present invention, tenter stretching is preferably used, and in order to control the slow axis with high accuracy, the difference between the left and right tenter clip speeds, separation timing, etc. is made as small as possible. It is preferable.

  A plasticizer can be added to the cellulose acylate film in order to improve mechanical properties or increase the drying rate. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP), diphenyl biphenyl phosphate and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalate esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and di-2-ethylhexyl phthalate (DEHP). . Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. The addition amount of the plasticizer is preferably 0.1 to 25% by mass of the amount of cellulose ester, more preferably 1 to 20% by mass, and most preferably 3 to 15% by mass.

A degradation inhibitor (for example, an antioxidant, a peroxide decomposer, a radical inhibitor, a metal deactivator, an acid scavenger, an amine) or an ultraviolet ray inhibitor may be added to the cellulose acylate film. The deterioration inhibitors are described in JP-A-3-199201, JP-A-597073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. The addition amount of the deterioration preventing agent is preferably 0.01 to 1% by mass of the solution (dope) to be prepared, and more preferably 0.01 to 0.2% by mass. When the addition amount is less than 0.01% by mass, the effect of the deterioration preventing agent is hardly recognized. By setting the addition amount to 1% by mass or more, bleeding out (bleeding) of the deterioration preventing agent to the film surface can be more effectively suppressed.
As a particularly preferred example of the deterioration preventing agent, butylated hydroxytoluene (BHT) can be mentioned. The ultraviolet ray preventing agent is described in JP-A-7-11056.

The cellulose acylate film is preferably subjected to a surface treatment. Specific examples include corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, alkali treatment, and ultraviolet irradiation treatment. In addition, as described in JP-A-7-333433, it is preferable to provide an undercoat layer.
From the viewpoint of maintaining the flatness of the film, the temperature of the cellulose acylate film in these treatments is preferably set to a glass transition temperature (Tg) or lower, specifically 150 ° C. or lower.

  As for the surface treatment of the cellulose acylate film, it is particularly preferable to carry out an acid treatment or an alkali treatment, that is, a saponification treatment on the cellulose acylate, from the viewpoint of adhesion to an alignment film or the like. Hereinafter, the alkali saponification treatment will be specifically described as an example. The alkali saponification treatment is preferably performed in a cycle in which the film surface is immersed in an alkali solution, neutralized with an acidic solution, washed with water and dried. Examples of the alkaline solution include potassium hydroxide solution and sodium hydroxide solution. The concentration of hydroxide ions is preferably in the range of 0.1 to 3.0 mol / L, and more preferably in the range of 0.5 to 2.0 mol / L. The alkaline solution temperature is preferably in the range of room temperature (for example, 18 ° C.) to 90 ° C., more preferably in the range of 40 to 70 ° C.

The surface energy of the cellulose acylate film is preferably 55 mN / m or more, and more preferably in the range of 60 to 75 mN / m.
The surface energy can be determined by a contact angle method, a wet heat method, and an adsorption method as described in “Basics and Applications of Wetting” (issued by Realize 1989.12.10). In the case of the cellulose acylate film used in the present invention, it is preferable to use a contact angle method. Specifically, two kinds of solutions having known surface energies are dropped on a cellulose acylate film, and at the intersection of the surface of the droplet and the surface of the film, the angle formed between the tangent line drawn on the droplet and the film surface, The surface angle of the film can be calculated by defining the angle containing the droplet as the contact angle.

  The thickness of the cellulose acylate film used as the support is preferably 5 to 500 μm, more preferably 20 to 250 μm, still more preferably 30 to 180 μm, and particularly preferably 30 to 110 μm.

The retardation plate of the present invention can be used for an elliptically polarizing plate in combination with a polarizing film. Furthermore, application to a transmissive, reflective, and transflective liquid crystal display device in combination with a polarizing film can contribute to an increase in the viewing angle of the device.
[Elliptically polarizing plate]
An elliptically polarizing plate can be produced by laminating the retardation plate of the present invention and a polarizing film. By using the retardation plate of the present invention, an elliptically polarizing plate capable of expanding the viewing angle of a liquid crystal display device can be provided.
Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film. The polarization axis of the polarizing film corresponds to a direction perpendicular to the stretching direction of the film.

  The polarizing film is laminated on the optically anisotropic layer side of the retardation plate. It is preferable to form a transparent protective film on the surface opposite to the side on which the retardation film of the polarizing film is laminated. The transparent protective film preferably has a light transmittance of 80% or more. As the transparent protective film, a cellulose ester film is preferably used, more preferably a triacetyl cellulose film. The cellulose ester film is preferably formed by a solvent cast method. The thickness of the transparent protective film is preferably 20 to 500 μm, and more preferably 50 to 200 μm.

[Liquid Crystal Display]
By using the retardation plate of the present invention, a liquid crystal display device with an enlarged viewing angle can be provided. 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. Further, an optical compensation sheet for liquid crystal cells in IPS mode or FLC mode is described in JP-A-10-54982. Furthermore, OCB mode or HAN mode liquid crystal cell optical compensation sheets are described in US Pat. No. 5,805,253 and WO 96/37804. Furthermore, an optical compensation sheet for an STN mode liquid crystal cell is described in JP-A-9-26572. A VA mode liquid crystal cell optical compensation sheet is described in Japanese Patent No. 2866372.

In the present invention, liquid crystal cell retardation plates (optical compensation sheets) of various modes can be prepared with reference to the above-mentioned publications. The phase difference plate of the present invention includes TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optical Compensation Bend), STN (Super Tamper Vw). It can be used for liquid crystal display devices of various display modes such as (Hybrid Aligned Nematic) mode.
The liquid crystal display device includes a liquid crystal cell, a polarizing element, and a phase difference plate (optical compensation sheet). A polarizing element generally comprises a polarizing film and a protective film. As the polarizing film and the protective film, those described for the elliptically polarized light can be used.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Example 1]
[Production of retardation plate]
(Production of polymer film (support))
The following composition was put into a mixing tank and stirred while heating to 30 ° C. to dissolve each component to prepare a cellulose acetate solution.
───────────────────────────────────
Cellulose acetate solution composition (parts by mass) Inner layer Outer layer ───────────────────────────────────
Cellulose acetate with an acetylation degree of 60.9% 100 100
Triphenyl phosphate (plasticizer) 7.8 7.8
Biphenyl diphenyl phosphate (plasticizer) 3.9 3.9
Methylene chloride (first solvent) 293 314
Methanol (second solvent) 71 76
1-butanol (third solvent) 1.5 1.6
Silica fine particles (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.)
0 0.8
The following retardation increasing agent 1.7 0
───────────────────────────────────

  The obtained inner layer dope and outer layer dope were cast on a drum cooled to 0 ° C. using a three-layer co-casting die. The film having a residual solvent amount of 70% by mass was peeled off from the drum, both ends were fixed with a pin tenter, and the film was dried at 80 ° C. while being transported at a draw ratio of 110% in the transport direction. By the way, it was dried at 110 ° C. Thereafter, it was dried at 140 ° C. for 30 minutes to produce a cellulose acetate film (outer layer: 3 μm, inner layer: 74 μm, outer layer: 3 μm) having a residual solvent of 0.3 mass%. The optical properties of the produced cellulose acetate film (film PK-1) were measured.

The obtained film PK-1 had a width of 1340 mm and a thickness of 80 μm. It was 6 nm when the retardation value (Re) in wavelength 500nm was measured using the ellipsometer (M-150, JASCO Corporation make). Further, the retardation value (Rth) in the thickness direction at a wavelength of 500 nm was measured and found to be 83 nm.
The produced film PK-1 was immersed in a 2.0N potassium hydroxide solution (25 ° C.) for 2 minutes, then neutralized with sulfuric acid, washed with pure water and dried.

(Preparation of alignment film)
An alignment film coating solution having the following composition was applied to the surface (alkaline treated surface) of the film PK-1 with a # 16 wire bar coater at 28 ml / m ² . The film was dried by warm air of 60 ° C. for 60 seconds, and further by warm air of 90 ° C. for 150 seconds.

───────────────────────────────────
Alignment film coating solution composition ───────────────────────────────────
Denatured polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde (crosslinking agent) 0.5 parts by weight Citrate ester (AS3 manufactured by Sankyo Chemical) 0.35 parts by weight ──────── ────────────────────────────

(Rubbing process)
The film PK-1 is transported at a speed of 20 m / min, a rubbing roll (300 mm diameter) is set so as to be rubbed at 0 ° with respect to the longitudinal direction, and rotated at 650 rpm. A rubbing treatment was applied to the surface of the film formed in (1) to form an alignment film.

(Formation of optically anisotropic layer)
On the rubbing surface of the alignment film, an optically anisotropic layer coating solution having the following composition is conveyed at 20 m / min by rotating a # 3.0 wire bar in 391 rotations in the same direction as the film conveyance direction. It was continuously applied to the alignment film surface.
───────────────────────────────────
1,3,5-substituted benzene type discotic liquid crystal compound (TD1)
91.00 parts by mass Discotic compound (Exemplary compound TP-1) 9.00 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 3.00 parts by mass sensitizer (Kayacure DETX, Nippon Kayaku Co., Ltd.) )) 1.00 parts by mass of fluoroaliphatic group-containing copolymer 1.00 parts by mass (Megafac F780 manufactured by Dainippon Ink, Inc.)
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 the film surface wind speed of the discotic liquid crystal compound layer is 2.5 m / sec in a drying zone of 110 ° C. The discotic liquid crystal compound was hybrid-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) in a state where the surface temperature of the film is about 90 ° C. Irradiation was carried out for 4 seconds to advance the crosslinking reaction, and the discotic liquid crystal 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. In this way, a retardation film 01 was produced.
Further, in the production of the retardation plate 01, the retardation plates 02 to 04 were similarly prepared except that 9 parts by mass of the exemplary compound TP-1 used as the discotic compound was replaced with the liquid crystal compounds shown in Table 1 below. Each was produced.

[Example 2]
Using the film PK-1 used in Example 1, an alignment film was formed on the surface in the same manner as in Example 1.
Next, in the formation of the optically anisotropic layer, Exemplified Compound D-112 was used at the same blending ratio in place of the 1,3,5-substituted benzene type discotic liquid crystal compound (TD1) used in Example 1. Formed an optically anisotropic layer in the same manner as in Example 1 to prepare a retardation film 05.

  Further, in the production of the phase difference plate 05, the phase difference plates 06 to 08 were similarly prepared except that 9 parts by mass of the exemplified compound TP-1 used as the discotic compound was replaced with the liquid crystal compounds shown in Table 1 below. Each was produced.

[Comparative Example 1]
A comparative retardation plate A was prepared in the same manner as in Example 1 except that the optically anisotropic layer coating solution having the following composition was used.
───────────────────────────────────
1,3,5-substituted benzene type discotic liquid crystal compound (TD1)
100.00 parts 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 of fluoroaliphatic group-containing copolymer 1.00 parts by mass (Megafac F780, Dainippon Ink Co., Ltd.)
Methyl ethyl ketone 226.34 parts by mass───────────────────────────────────

[Comparative Example 2]
In Comparative Example 1, an optically anisotropic layer was formed in the same manner as in Comparative Example 1 except that Exemplified Compound D-112 was used at the same blending ratio instead of the 1,3,5-substituted benzene type discotic liquid crystal compound (TD1). The retardation plate B was produced.

[Formation of tilt angle measurement cell and preparation of tilt angle measurement sample]
<Formation of alignment film>
After the 1.1 mm-thick glass was washed, the alignment film coating solution was applied to the glass with a wire bar coater at a coating amount of 20 ml / m ² . Drying was performed with warm air of 60 ° C. for 60 seconds and further with warm air of 90 ° C. for 150 seconds.
Next, using a rubbing roller having a diameter of 65 mm wound with rayon as a rubbing cloth, a reciprocating rubbing treatment was performed at room temperature at a rotation speed of 1000 rpm. At this time, the indentation length of the bristles was set to 0.1 mm and the rubbing process was performed.

  The prepared glass support with orientation is cut into a size of 1.5 cm × 2.0 cm, and is opposed so that the rubbing direction is the anti-parallel rubbing direction, and a polymer film having a thickness of 100 μm is sandwiched between them as a spacer. Then, the periphery was fixed with an adhesive to produce a cell for measuring the pretilt angle before polymerization. Next, a coating solution for measuring a tilt angle (a solution obtained by adding 2 parts by mass of a polymerization inhibitor (Irganox 1010, manufactured by Ciba Geigy Co., Ltd., molecular weight 1176) to the coating solution of the optically anisotropic layer used in the above examples and comparative examples) ), And after mixing and stirring, the solvent was removed using an evaporator to obtain a composition for measuring a pretilt angle. In order to remove residual solvent and air bubbles contained in this composition, it was heated on a hot plate at 130 ° C. for 30 minutes. This was injected into the manufactured pretilt angle measuring cell heated to 130 ° C.

<Measurement of tilt angle (before polymerization)>
After pouring into the cell, it was held at 130 ° C. until uniform orientation was obtained. Then, using the crystal rotation method, it measured at the temperature of 90 degreeC and calculated | required the tilt angle. For the measurement, a He—Ne laser (633 nm) was used as a light source. The preparation and measurement of the composition were all performed under a yellow lamp, and the composition was recovered after the pretilt angle measurement, and it was confirmed by NMR measurement that no polymerization reaction occurred.

[Evaluation of retardation plate]
About each of the obtained phase difference plate, the orientation state was confirmed visually by observation in the crossed Nicol which provided the polarizing microscope (ECLIPSE LV100POL made from Nikon) and the backlight. The results are shown in Table 1. In addition, the polarizing microscope observation photographs of the retardation plates 01 to 04 are shown in FIG. 1 (all the same observation photographs were obtained, so the observation photograph of the retardation plate 01 is shown in FIG. 1 as a representative), and the retardation plate A A polarizing microscope observation photograph is shown in FIG.

  From the results of Table 1 and FIG. 1, it can be understood that none of the retardation plates 01 to 08 of the example has a streak-like defect. On the other hand, many streak-like defects were observed in the retardation plates A and B produced using a liquid crystal composition not using a discotic compound. As shown in Table 1, in the comparative example, the tilt angle on the alignment film of the liquid crystal composition before polymerization was large, whereas in the example, the tilt angle was reduced by the action of the discotic compound. This is considered to be affected by the angle of 12 ° or less.

It is a polarizing microscope observation photograph of the phase difference plate of an Example. It is a polarizing microscope observation photograph of the phase difference plate of a comparative example.

Claims (5)

A retardation plate having a support and an optically anisotropic layer formed from the liquid crystal composition on the support,
The support is a polymer film;
The liquid crystal composition includes a 1,3,5-substituted benzene discotic liquid crystal compound represented by the following general formula (DI), and a compound having a discotic structure represented by the following general formula (TI) as a partial structure: Containing
A phase difference plate having a mass ratio of 97: 3 to 80:20 between the 1,3,5-substituted benzene type discotic liquid crystal compound and the compound having the discotic structure as a partial structure.

(In General Formula (DI), Y ¹¹ , Y ¹² and Y ¹³ each independently represent a methine or nitrogen atom, and R ¹¹ , R ¹² and R ¹³ are each independently the following General Formula (DI-A), (Represented by the following general formula (DI-B) or the following general formula (DI-C))

(In the general formula (DI-A), A ¹¹ and A ¹² represent nitrogen atoms, A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ represent methine, X ¹ represents an oxygen atom, and L ¹¹ represents —O —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C. L ¹² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and —C≡C— and represents a divalent linking group selected from the group consisting of, when the group has contains hydrogen atom, the hydrogen atom in each good .Q ¹¹ be substituted with a substituent independently Represents a polymerizable group or a hydrogen atom.)

(In the general formula (DI-B), A ²¹ and A ²² represent nitrogen atoms, A ²³ , A ²⁴ , A ²⁵ and A ²⁶ represent methine, X ² represents an oxygen atom, and L ²¹ represents —O —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C. L ²² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and —C≡C— and represents a divalent linking group selected from the group consisting of, when the group has contains hydrogen atom, the hydrogen atom in each good .Q ²¹ be substituted with a substituent independently Represents a polymerizable group or a hydrogen atom.)

(In the general formula (DI-C), A ³¹ and A ³² represent nitrogen atoms, A ³³ , A ³⁴ , A ³⁵ and A ³⁶ represent methine, X ³ represents an oxygen atom, and L ³¹ represents —O —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C. L ³² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and —C≡C— and represents a divalent linking group selected from the group consisting of, when the group has contains hydrogen atom, the hydrogen atom in each good .Q ³¹ be substituted with a substituent independently Represents a polymerizable group or a hydrogen atom.)

(In the general formula (TI), L ¹ each independently represents —O—, —S—, —NH—; R ¹ is represented by the following formula (R-IA).)
Formula (R-IA)
^{* -Cy 1 - (L 1A -Cy} 2) p -L 2A - (L 3A) r -Q 1A
(In formula (R-IA), * represents a position bonded to L ¹ , Cy ¹ and Cy ² each represents a divalent linking group having a 5- to 7-membered ring, and L ^1A represents a single bond or — A divalent group selected from the group consisting of O—, —S—, —C (═O) —, —NR ⁷ —, —CH ₂ — , —CH═CH—, —C≡C—, and combinations thereof. Represents a linking group (R ⁷ is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom), and L ^2A is a single bond or —O—, —S—, —C (═O) —, —NR ^7. -Represents a divalent linking group selected from the group consisting of a combination thereof (R ⁷ is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom), L ^3A is an alkylene group, a substituted alkylene group, alkenylene group, substituted alkenylene group, an alkynylene group, or a substituted alkynylene group, Q ^1A is hydrogen atom or the following (M- ) Is a polymerizable group represented by ~ (M-6), p represents an integer of 0 to 2; r is 0 or 1).

(In the above (M-3) and (M-4), R represents a hydrogen atom or an alkyl group.) In the general formula (TI), L ^1A represents a single bond, * - O-CO -, * - CO-O -, * - CH 2 -CH 2 -, * - O-CH 2 -, * - CH 2 - O—, * —CO—CH ₂ —CH ₂ —, * —CH═CH—, or * —C≡C— (where, * represents a position linked to Cy ¹ in the formula (R-IA)). The phase difference plate according to claim 1, wherein In the general formula (TI), L ^2A is a single bond, * —O—, * —O—CO—, * —CO—O—, * —O—CO—O—, * —CO—, * —S. - or * -NR ⁷ - (wherein, R ⁷ is an alkyl group or a hydrogen atom 1-7 carbon atoms, and * bivalent having a 5- to 7-membered ring in formula (R-IA) The retardation plate according to claim 1, wherein the retardation plate represents a position to be connected to a connecting group.   The alignment film according to any one of claims 1 to 3, further comprising an alignment film between the support and the optically anisotropic layer, wherein the alignment film contains a partially saponified polyvinyl alcohol derivative. The retardation plate described. A method for producing a retardation plate comprising a step of forming an optically anisotropic layer using a liquid crystal composition on a support,
The support is a polymer film;
The liquid crystal composition includes a 1,3,5-substituted benzene discotic liquid crystal compound represented by the following general formula (DI), and a compound having a discotic structure represented by the following general formula (TI) as a partial structure: Containing
The mass ratio of the 1,3,5-substituted benzene type discotic liquid crystal compound to the compound having the discotic structure as a partial structure is 97: 3 to 80:20,
In the step of forming the optically anisotropic layer, the alignment step of aligning the molecules of the 1,3,5-substituted benzene type discotic liquid crystal compound on the surface of the alignment film and the alignment state obtained in the alignment step are fixed. The manufacturing method of the phase difference plate characterized by including a process.

(In General Formula (DI), Y ¹¹ , Y ¹² and Y ¹³ each independently represent a methine or nitrogen atom, and R ¹¹ , R ¹² and R ¹³ are each independently the following General Formula (DI-A), (Represented by the following general formula (DI-B) or the following general formula (DI-C))

(In the general formula (DI-A), A ¹¹ and A ¹² represent nitrogen atoms, A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ represent methine, X ¹ represents an oxygen atom, and L ¹¹ represents —O —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C. L ¹² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and —C≡C— and represents a divalent linking group selected from the group consisting of, when the group has contains hydrogen atom, the hydrogen atom in each good .Q ¹¹ be substituted with a substituent independently Represents a polymerizable group or a hydrogen atom.)

(In the general formula (DI-B), A ²¹ and A ²² represent nitrogen atoms, A ²³ , A ²⁴ , A ²⁵ and A ²⁶ represent methine, X ² represents an oxygen atom, and L ²¹ represents —O —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C. L ²² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and —C≡C— and represents a divalent linking group selected from the group consisting of, when the group has contains hydrogen atom, the hydrogen atom in each good .Q ²¹ be substituted with a substituent independently Represents a polymerizable group or a hydrogen atom.)

(In the general formula (DI-C), A ³¹ and A ³² represent nitrogen atoms, A ³³ , A ³⁴ , A ³⁵ and A ³⁶ represent methine, X ³ represents an oxygen atom, and L ³¹ represents —O —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C. L ³² represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and —C≡C— and represents a divalent linking group selected from the group consisting of, when the group has contains hydrogen atom, the hydrogen atom in each good .Q ³¹ be substituted with a substituent independently Represents a polymerizable group or a hydrogen atom.)

(In the general formula (TI), L ¹ each independently represents —O—, —S—, —NH—; R ¹ is represented by the following formula (R-IA).)
Formula (R-IA)
^{* -Cy 1 - (L 1A -Cy} 2) p -L 2A - (L 3A) r -Q 1A
(In formula (R-IA), * represents a position bonded to L ¹ , Cy ¹ and Cy ² each represents a divalent linking group having a 5- to 7-membered ring, and L ^1A represents a single bond or — A divalent group selected from the group consisting of O—, —S—, —C (═O) —, —NR ⁷ —, —CH ₂ — , —CH═CH—, —C≡C—, and combinations thereof. Represents a linking group (R ⁷ is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom), and L ^2A is a single bond or —O—, —S—, —C (═O) —, —NR ^7. -Represents a divalent linking group selected from the group consisting of a combination thereof (R ⁷ is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom), L ^3A is an alkylene group, a substituted alkylene group, alkenylene group, substituted alkenylene group, an alkynylene group, or a substituted alkynylene group, Q ^1A is hydrogen atom or the following (M- ) Is a polymerizable group represented by ~ (M-6), p represents an integer of 0 to 2; r is 0 or 1).

(In the above (M-3) and (M-4), R represents a hydrogen atom or an alkyl group.)

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