JPH11158258A - Optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel optical film which is easy to fix the liquid crystal alignment and the alignment state to glass and has excellent holding ability of the liquid crystal alignment state, and is suitable for application to an optical element. SOLUTION: The following structural units (A) and (B)
As an essential structural unit, exhibits a glassy state at a temperature lower than the liquid crystal transition point, and has a logarithmic viscosity η measured at 30 ° C. in a phenol / tetrachloroethane mixed solvent (weight ratio of 60/40) of 0.04 to A liquid crystal material having a nematic liquid crystal polyester of 0.4 dl / g as an essential component and having a twisted nematic alignment in a liquid crystal state is formed into a film. Embedded image X independently represents O or C = O. Y represents a group independently selected from F, Cl, Br and an alkyl group having 1 to 4 carbon atoms. Further, n is 0 or 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optical film which is easy to fix liquid crystal alignment and alignment state to glass and has excellent holding ability of liquid crystal alignment state, and is suitable for application to an optical element.

[0002]

2. Description of the Related Art Various types of polymer liquid crystals have been developed and commercialized in the field of high-performance materials utilizing mechanical properties such as high elasticity, high rigidity, heat resistance and good moldability. It is well known that a polymer liquid crystal has both the structural and optical anisotropy of the liquid crystal and the ability to fix the orientation derived from the polymer. In recent years, research and development for using polymer liquid crystals in the field of functional materials, such as optical members for liquid crystal display elements, utilizing the above properties have been actively conducted.

Here, in order to make full use of the optical anisotropy of the polymer liquid crystal, it is necessary to sufficiently align the liquid crystal molecules. In order to enhance the orientation of the liquid crystal molecules, it is preferable that the structural unit of the high-molecular liquid crystal is a structural unit obtained from a bifunctional compound, and that the molecular units have a molecular structure in which these structural units are arranged on a straight line. . From such a viewpoint, as a polymer liquid crystal having a fixed twisted nematic alignment used in an optical element, Japanese Patent No. 2,592,694 is used.
No. 2,595,701, etc., it is composed only of structural units obtained from a bifunctional compound. However, when an external element is applied at a temperature equal to or higher than the glass transition point, the orientation of the optical elements produced from these polymer liquid crystals is disturbed, and the optical element is not sufficient in terms of the ability to maintain the orientation.

[0004]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found a polymer liquid crystal which is easy to fix the liquid crystal alignment to glass and has excellent alignment holding ability. The above problem has been solved by developing a film using liquid crystal.

[0005]

Means for Solving the Problems The present inventors have made it possible to improve the alignment ability and the alignment holding ability by forming a film using a liquid crystalline polyester having a specific structural unit introduced into a polymer chain constituting a main chain. Invented an excellent new optical film. That is, the present invention firstly has the following structural units (A) and (B) as essential structural units, exhibits a glassy state at a temperature lower than the liquid crystal transition point, and has a phenol /
In a tetrachloroethane mixed solvent (weight ratio 60/40),
Logarithmic viscosity η measured at 30 ° C. is 0.04 to 0.4 dl /
The present invention relates to an optical film substantially formed of a liquid crystal substance which is twisted and nematically aligned in a liquid crystal state and has a liquid crystal polyester as an essential component. A second aspect of the present invention relates to the first optical film, wherein the liquid crystalline substance is a twisted nematic liquid crystalline polyester having an optically active group in a molecule of the liquid crystalline polyester. A third aspect of the present invention relates to the first optical film, wherein the liquid crystal substance is a composition substantially comprising a liquid crystal polyester and an optically active compound, and the liquid crystal polyester is a nematic liquid crystal polyester.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The liquid crystalline substance used in the present invention exhibits a glassy state at a liquid crystal transition point or lower, has structural units represented by the following (A) and (B) as essential structural units, and has a phenol / tetrachloroethane mixed solvent ( Weight ratio 60/4
0), the logarithmic viscosity η measured at 30 ° C. is 0.04 to 0.4.
It is a liquid crystal state having a liquid crystalline polyester of 4 dl / g as an essential component and is subjected to twisted nematic alignment. The structural units other than the structural units (A) and (B) in the liquid crystalline polyester are not particularly limited as long as the above conditions are satisfied.

More specifically, the liquid crystal substance used in the present invention is a composition of a nematic liquid crystal polyester having structural units (A) and (B) as essential structural units and an optically active low molecular compound. A composition of a nematic liquid crystalline polyester having the structural units (A) and (B) as essential structural units and an optically active polymer compound; having the structural units (A) and (B) as essential structural units, There is a twisted nematic liquid crystalline polyester having an optically active group. The nematic liquid crystalline polyester described above and above forms a nematic alignment having no twist structure in a liquid crystal state.

First, the structural units (A) and (B) will be described. The structural unit (A) includes trimesic acid (1,
3,5-benzenetricarboxylic acid), trimertic acid (1,2,4-benzenetricarboxylic acid), phloroglicinol (1,3,5-trihydroxybenzene) and structural units formed from these derivatives is there. In the present invention, a unit formed from trimesic acid and its derivative is particularly preferable.

The structural unit (A) is usually 0.05 to 15 mol%, preferably 0.10 to 7.5 mol%, particularly preferably 0.2 to 0.2 mol% in the structural units constituting the liquid crystalline polyester.
0-5 mol% is contained. If the amount is less than 0.05 mol%, there is a possibility that no improvement in the orientation holding ability can be obtained. Also one
If it is more than 5 mol%, the alignment ability may be significantly reduced. The structural unit (B) is a structural unit formed from catechol and its derivatives. In particular,

[0010]

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And the like. Of these,

[0012]

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Is preferred. The structural unit (B) generally contains 4.5 to 60 mol%, preferably 6 to 60 mol%, of the structural units constituting the liquid crystalline polyester. If the amount is less than 4.5 mol%, the liquid crystal alignment may not be fixed to glass. Here, the nematic liquid crystalline polyester is
Other structural units are not particularly limited as long as the structural units (A) and (B) are essential structural units and the structural units are included in a bond forming a main chain. An appropriate structural unit capable of forming a polyester structure is used. Examples of the structural units other than the structural units (A) and (B) include aromatic structural units such as the following structural units (C), (D) and (E).

[0014]

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In the above formula, A and B each represent a carbonyl bond (CＣO) or oxygen (O), and may be the same or different. X and Y are each hydrogen, F, Cl, Br
And an alkyl group having 1 to 4 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, n-butyl,
sec-butyl group, tert-butyl group, etc.), and may be the same or different, and m and n each represent an integer of 0 to 4, and may be the same or different.

These structural units include terephthalic acid or a derivative thereof, substituted terephthalic acid or a derivative thereof, hydroquinone or a derivative thereof, substituted hydroquinone or a derivative thereof, 4-hydroxybenzoic acid or a derivative thereof,
Substituted 4-hydroxybenzoic acid or its derivative, isophthalic acid or its derivative, substituted isophthalic acid or its derivative, resorcinol or its derivative, substituted resorcinol or its derivative, 3-hydroxybenzoic acid or its derivative, substituted 3-hydroxybenzoic acid or A derivative thereof, 4,4′-biphenyldicarboxylic acid or a derivative thereof, a substituted 4,4′-biphenyldicarboxylic acid or a derivative thereof, 4,4′-biphenol or a derivative thereof, a 4,4′-substituted biphenol or a derivative thereof,
4′-hydroxy-4-biphenylcarboxylic acid or a derivative thereof, substituted 4′-hydroxy-4-biphenylcarboxylic acid or a derivative thereof, 2,6-naphthalenedicarboxylic acid or a derivative thereof, substituted 2,6-naphthalenedicarboxylic acid or a derivative thereof A derivative, 2,6-naphthalenediol or a derivative thereof, a substituted 2,6-naphthalenediol or a derivative thereof, 6-hydroxy-2-naphthoic acid or a derivative thereof, or a substituted 6-hydroxy-2-naphthoic acid or a derivative thereof. The following units can be specifically exemplified.

[0017]

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[0018]

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[0019]

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[0020]

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Among these,

[0022]

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[0023]

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[0024]

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Is suitable as a structural unit constituting a nematic liquid crystalline polyester. In addition to the above structural units,

[0026]

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Such structural units are also suitable as the units constituting the nematic liquid crystalline polyester. Here, as the nematic liquid crystalline polyester, as described above,
(A) a unit derived from trimesic acid as the structural unit (A) (hereinafter, referred to as trimesic acid structural unit);
(A) units derived from catechols which are structural units (B) (hereinafter referred to as catechol structural units), (c)
Units derived from dicarboxylic acids (hereinafter referred to as dicarboxylic acid structural units), (d) units derived from diols other than catechol (hereinafter referred to as diol structural units), (e) carboxyl in one structural unit It is usually composed of units derived from oxycarboxylic acids having both a group and a hydroxyl group (hereinafter referred to as oxycarboxylic acid structural units).

The structure of the polyester is as follows:
+ (B) + (c) type, (a) + (b) + (c) + (d)
Type, (A) + (A) + (U) + (E) type, (A) +
(A) + (c) + (d) + (e) types.

The ratio of each structural unit in the nematic liquid crystalline polyester cannot be unconditionally determined because the optimum value of the ratio of each structural unit differs depending on the structural units constituting the polyester. Normally, the ratio of the total number of functional groups of the diol structural unit and the catechol structural unit to the total number of functional groups of the dicarboxylic acid structural unit and the trimesic acid structural unit is usually in the range of 0.90 to 1.20, preferably 0.95 to 1.20. 1.
It is in the range of 10, particularly preferably in the range of 1.00 to 1.05. The ratio of trimesic acid structural units to the sum of dicarboxylic acid units and trimesic acid units is usually 0.5%.
-30 mol%, preferably 1.0-15 mol%, particularly preferably 2.0-10 mol%. The ratio of the catechol structural unit to the total of the diol structural unit and the catechol structural unit is usually 30 to 10%.
It is in the range of 0 mol%, preferably in the range of 40 to 100 mol%. Further, the ratio of the hydroxycarboxylic acid structural unit to the total structural unit is usually in the range of 0 to 60 mol%, preferably in the range of 0 to 50 mol%, particularly preferably in the range of 0 to 40 mol%. Here, a specific structure of a suitable nematic liquid crystalline polyester that can be used in the present invention will be exemplified below. The present invention is not at all limited to the following polyesters.

[0030]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0032]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0034]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0036]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0038]

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2f / (2c + 2d + 3e) = 0.90
1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 e / (c + d + e) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably Is 0.02-0.
10 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0040]

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2f / (2c + 2d + 3e) = 0.90
1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 e / (c + d + e) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably Is 0.02-0.
10 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0042]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0044]

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2e / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e) = 0 to 0.6 (a, b, c, d and e each indicate a molar composition ratio)

[0046]

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(2e + 2f) / (2b + 2c + 3d) =
0.90 to 1.20, preferably 0.95 to 1.10,
Particularly preferably, 1.00 to 1.05 d / (b + c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.
10 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0048]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0050]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0052]

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(2e + 2f) / (2b + 2c + 3d) =
0.90 to 1.20, preferably 0.95 to 1.10,
Particularly preferably, 1.00 to 1.05 d / (b + c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.
10 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0054]

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2e / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e) = 0 to 0.6 (a, b, c, d and e each indicate a molar composition ratio)

[0056]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0058]

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2e / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e) = 0 to 0.6 (a, b, c, d and e each indicate a molar composition ratio)

[0060]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

[0062]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (e + f) = 0.3 to 1.0, preferably 0.4 to
1.0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, and f each indicate a molar composition ratio)

The nematic liquid crystalline polyester as described above can be synthesized by applying a polymerization method known in the art, for example, a melt polymerization method or a solution polymerization method.

When the liquid crystalline polyester is synthesized by a melt polymerization method, for example, a predetermined amount of trimesic acid (monomer forming the structural unit (A)), an acetylated catechol (monomer forming the structural unit (B)) and optionally a dicarboxylic acid (Monomer forming dicarboxylic acid structural unit), acetylated product of diol (monomer forming diol structural unit), acetylated product of hydroxycarboxylic acid (monomer forming hydroxycarboxylic acid structural unit), etc. under high temperature, normal pressure, reduced pressure or high vacuum The desired polyester can be easily obtained by copolymerization.

As described above, the proportion of trimesic acid (structural unit (A) forming monomer) in the polyester is 0.05 to 15 mol%, preferably 0 to 15 mol%, as described above. .10
7.5 mol%, particularly preferably 0.20 to 5 mol
%, And catechols (monomer forming the structural unit (B)) are set to be 4.5 to 60 mol%, preferably 6 to 60 mol%. Dicarboxylic acid (dicarboxylic acid structural unit-forming monomer), diol (diol structural unit-forming monomer) and hydroxycarboxylic acid (hydroxycarboxylic acid structural unit-forming monomer), which are other optional components, are also diol structural unit and catechol structural unit. The ratio of the sum of the number of functional groups of the above and the sum of the number of functional groups of the dicarboxylic acid structural unit and the trimesic acid structural unit is in the range of 0.90 to 1.20, preferably in the range of 0.95 to 1.10. The ratio of the trimesic acid structural unit to the total of the dicarboxylic acid unit and trimesic acid unit is usually in the range of 0.5 to 30 mol%, preferably 1.0 to 15 mol%. Catechol structural unit and diol structure of catechol structural unit A percentage of the position of the sum, usually 30~100mo
1%, preferably in the range of 40 to 100 mol%, and the ratio of the hydroxycarboxylic acid structural unit to the total structural units is generally in the range of 0 to 60 mol%, preferably in the range of 0 to 50 mol%, and particularly preferably 0. ~ 40 mol%
Set so that it is within the range.

The polymerization conditions are not particularly limited, but the temperature is usually 150 to 350 ° C., preferably 200 to 300 ° C., and the reaction time is 30 minutes or more, preferably about 1 to 20 hours. In order to promote the polymerization reaction, for example, 1-
Amines such as methylimidazole and 4-dimethylaminopyridine, alkali metals, Fe, Mn, Ti, Co, S
Metal salts such as b and Sn may be used alone or in combination. Further, for the purpose of reducing the coloring of the polyester, various antioxidants can be added to synthesize the polyester. Further, the molecular weight of the polyester can be easily adjusted by controlling the polymerization time as in the ordinary condensation reaction.

Here, the molecular weight of the liquid crystalline polyester is determined by the phenol / tetrachloroethane mixed solvent (weight ratio: 60 /
40), the value of the logarithmic viscosity measured at 30 ° C. is usually 0.0
4 to 0.4 dl / g, more preferably 0.06 to 0.3
dl / g, particularly preferably 0.1 to 0.25 dl
/ G range. When the logarithmic viscosity is less than 0.05 dl / g, the strength of the film made from the polyester becomes weak, and when the logarithmic viscosity is more than 0.4 dl / g,
The viscosity at the time of forming the liquid crystal is high, and the alignment property is reduced, and the time required for the alignment becomes longer, which is not preferable.

When the liquid crystalline polyester to be used in the present invention is synthesized by a solution polymerization method, for example, a predetermined amount of trimesic acid (monomer forming structural unit (A)), dicarboxylic acid (monomer forming dicarboxylic acid structural unit), and After converting a hydroxycarboxylic acid (a monomer for forming a hydroxycarboxylic acid structural unit) to a halide compound by allowing a chlorinating agent such as thionyl chloride to act thereon, catechols and diols dissolved in a solvent in which an acid acceptor such as pyridine is present are dissolved. By dropping and reacting at room temperature or under heating,
The desired polyester can be easily obtained. The charging ratio of each monomer is the same as in the above-mentioned melt polymerization method, and the trimesic acid derivative (the monomer forming the structural unit (A)) is 0.1%.
05 to 15 mol%, more preferably 0.10 to 7.5.
mol%, particularly preferably 0.20 to 5 mol%, of catechols (monomer forming structural unit (B)) of 4.5 to 6
It is set so as to contain 0 mol%, preferably 6 to 60 mol%. Dicarboxylic acid (dicarboxylic acid structural unit-forming monomer), diol (diol structural unit-forming monomer) and hydroxycarboxylic acid (hydroxycarboxylic acid structural unit-forming monomer), which are other optional components, are also diol structural unit and catechol structural unit. The ratio of the sum of the number of functional groups of the above and the sum of the number of functional groups of the dicarboxylic acid structural unit and the trimesic acid structural unit is in the range of 0.90 to 1.20, preferably in the range of 0.95 to 1.10. The ratio of the trimesic acid structural unit to the total of the dicarboxylic acid unit and trimesic acid unit is usually in the range of 0.5 to 30 mol%, preferably 1.0 to 15 mol%. Catechol structural unit and diol structure of catechol structural unit A percentage of the position of the sum, usually 30~100mo
1%, preferably in the range of 40 to 100 mol%, and the ratio of the hydroxycarboxylic acid structural unit to the total structural units is generally in the range of 0 to 60 mol%, preferably in the range of 0 to 50 mol%, and particularly preferably 0. ~ 40 mol%
Set so that it is within the range.

The solvent used in the solution polymerization is not particularly limited. For example, halogen solvents such as o-dichlorobenzene, dichloroethane and tetrachloroethane, dimethylsulfoxide (DMSO), dimethylformamide (DMF), N-methylpyrrolidone ( Polar solvents such as NMP) and ether solvents such as tetrahydrofuran (THF) and dioxane. Examples of the acid acceptor include, but are not particularly limited to, pyridine, triethylamine, and tripropylamine.

The reaction conditions for the solution polymerization are not particularly limited, but are usually 50 to 200 ° C., preferably 60 to 200 ° C.
The reaction time at 150 ° C. is usually 1 hour or more, preferably 2 hours to 10 hours.

The nematic liquid crystalline polyester obtained as described above varies depending on the composition ratio and the like, and cannot be said unconditionally. However, it can usually form a monodomain nematic phase in a liquid crystal state. Further, when the liquid crystalline polyester in a liquid crystal state is cooled at an arbitrary cooling rate, substantially no phase transition to a crystal phase occurs. That is, the polyester shows a monodomain nematic phase in a liquid crystal state, and its alignment state can be easily fixed by cooling. In order to stably immobilize the nematic phase, when viewed from the liquid crystal phase series,
If a crystal phase is present in a lower temperature region than the nematic phase, it will inevitably pass through the crystal phase when cooling for immobilization, and as a result, the nematic orientation obtained once will be destroyed. The nematic liquid crystalline polyester used in the present invention basically exhibits a monodomain nematic phase in a liquid crystal state, and exhibits a glass state at a liquid crystal transition temperature or lower. Therefore, it has a feature that the molecular alignment state in the liquid crystal state, specifically, the nematic alignment state can be maintained as it is.

Next, an optically active compound mixed to impart a twist to the liquid crystalline polyester and form a twisted nematic alignment having a desired twist angle will be described. The compound is not particularly limited as long as it is an optically active compound, but in the present invention, an optically active liquid crystal compound is suitable from the viewpoint of compatibility with the above-mentioned nematic liquid crystalline polyester. Specifically, the following compounds can be exemplified. (In the formula, * indicates optically active carbon).

[0074]

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The optically active compounds that can be used in the present invention include optically active polymer compounds. The polymer compound is not particularly limited as long as it is a polymer having an optically active group in the molecule.However, in the present invention, an optically active compound is used from the viewpoint of compatibility with the above-described nematic liquid crystalline polyester. Liquid crystalline polymer compounds are preferred. As such a polymer compound,
For example, liquid crystalline polymethacrylate having an optically active group, polymalonate, polysiloxane, polyarylate, polyester, polyamide, polyesteramide,
Examples include polycarbonate, polypeptide, and cellulose. Among them, in the present invention, an aromatic-based optically active liquid crystalline polyester is most preferred from the viewpoint of compatibility and the like. Specifically, the following polyesters can be exemplified.

[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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[0090]

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[0091]

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[0092]

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[0093]

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The optically active liquid crystalline polyesters as described above include structural units derived from the above-mentioned monocarboxylic acids (hereinafter, referred to as monocarboxylic acid structural units (a)) and structural units derived from dicarboxylic acids (hereinafter, referred to as: A dicarboxylic acid structural unit (b)), a structural unit derived from a monool (hereinafter, a monool structural unit (c)), a structural unit derived from a diol (hereinafter, referred to as a diol structural unit (d)), And a structural unit appropriately selected from structural units derived from oxycarboxylic acids having both a carboxyl group and a hydroxyl group in one structural unit (referred to as oxycarboxylic acid structural unit (e)).

The method for synthesizing the optically active liquid crystalline polyester is not particularly limited. It can be synthesized by a method known in the art, for example, a melt polymerization method or a solution polymerization method. The content of the optically active group in the polyester is usually 0.5 to 80 mol%, preferably 5 to 80 mol%.
６０60 mol%. The molecular weight is 30 in a phenol / tetrachloroethane mixed solvent (weight ratio 60/40).
The logarithmic viscosity is usually 0.05 to 3.0 dl.
/ G, preferably 0.07 to 2.0 dl / g.
If it is less than 0.05 dl / g, it is difficult to control the polymerization reaction, which is not preferable. On the other hand, if it is larger than 3.0 dl / g, the melt viscosity becomes too high, which may take a long time to develop the liquid crystal, which is not desirable. In the present invention,
The composition of the optically active liquid crystalline polyester as described above and the nematic liquid crystalline polyester described above can be provided as the substance of the present invention. Specifically as such a composition,

[0096]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
０．３0.30 (weight ratio)) (2e + 2f) / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100 / 0-0 / 100 (a + b) / (a + b + c + d + e + f) = 0-0.6 f / (e + f) = 0.1-1.0 (h + i + j) /g=0.90-1. 20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.0
5 j / (g + h + i + j) = 0.005 to 0.80, preferably 0.05 to 0.60 (a, b, c, d, e, f, g, h, i, j are each molar composition ratios) Indicates)

[0098]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
０．３0.30 (weight ratio)) (2e + 2f) / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 f / (e + f) = 0.1 to 1.0 (g + h) /i=0.90 to 1. 20, preferably 0.
95-1.10, particularly preferably 1.00-1.05 i / (g + h + i) = 0.005-0.80, preferably 0.05-0.60 (a, b, c, d, e, f, g,
h and i each indicate a molar composition ratio)

[0100]

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Compositions of (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
-0.30 (weight ratio)) 2f / (2c + 2d + 3e) = 0.90 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00
1.05 e / (c + d + e) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.
10 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 h / g = 0.90 to 1.20, preferably 0.95 to
1.10, particularly preferably 1.00 to 1.05 (a, b, c, d, e, f, g, and h each represent a molar composition ratio)

[0102]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
2e / (2c + 3d) = 0.90 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.10 (weight ratio).
05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e) = 0 to 0.6 (h + i) /g=0.90 to 1.20, preferably 0.
95 to 1.10, particularly preferably 1.00 to 1.05 i / (f + g + h + i) = 0.005 to 0.80, preferably 0.05 to 0.60 (a, b, c, d, e, f, g, h, and i each represent a molar composition ratio)

[0104]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
０．３0.30 (weight ratio)) (2e + 2f) / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 f / (e + f) = 0.1 to 1.0 i / 2h = 0.90 to 1.20 Preferably 0.95-
1.10, particularly preferably 1.00 to 1.05 i / (g + h + i) = 0.005 to 0.80, preferably 0.05 to 0.60 (a, b, c, d, e, f, g, h, and i each represent a molar composition ratio)

[0106]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
０．３0.30 (weight ratio)) (2e + 2f) / (2b + 2c + 3d) = 0.90
1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (b + c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably Is 0.02-0.
10 a / (a + b + c + d + e + f) = 0 to 0.6 f / (e + f) = 0.1 to 1.0 j / i = 0.90 to 1.20, preferably 0.95 to
1.10, particularly preferably 1.00 to 1.05 j / (g + h + i + j) = 0.005 to 0.80, preferably 0.05 to 0.60 (a, b, c, d, e, f, g, h, i, and j each represent a molar composition ratio)

[0108]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
2e / (2c + 3d) = 0.90 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.10 (weight ratio).
05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e) = 0 to 0.6 h / (f + g) = 0.90 to 1.20, preferably 0.
95 to 1.10, particularly preferably 1.00 to 1.05 h / (f + g + h) = 0.005 to 0.80, preferably 0.05 to 0.60 (a, b, c, d, e, f, g and h each indicate a molar composition ratio)

[0110]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
０．３0.30 (weight ratio)) (2e + 2f) / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (2h + i) /2g=0.90 to 1.20, preferably 0.95 to 1.10. Preferably 1.00 to 1.0
5 i / (g + h + i) = 0.005 to 0.80, preferably 0.05 to 0.60 (a, b, c, d, e, f, g, h, and i each represent a molar composition ratio. )

[0112]

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Compositions (A) and (B) ((B) /
(A) = 0.001 to 0.50, preferably 0.005
０．３0.30 (weight ratio)) (2e + 2f) / (2c + 3d) = 0.90 to 1.2
0, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, and particularly preferably 0. .02-0.1
0 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 f / (e + f) = 0.1 to 1.0 (g + h) /i=0.90 to 1. 20, preferably 0.
95 to 1.10, particularly preferably 1.00 to 1.05 i / (g + h + i) = 0.005 to 0.80, preferably 0.05 to 0.60 (a, b, c, d, e, f, g, h, and i each represent a molar composition ratio)

The composition of the nematic liquid crystalline polyester and the optically active compound can be adjusted by a method such as solid mixing, solution mixing or melt mixing of the polyester and the optically active compound at a predetermined ratio.
Although the ratio of the optically active compound in the composition is different depending on the ratio of the optically active group in the compound or the twisting force when twisting the liquid crystalline polyester of the optically active compound, it cannot be said unconditionally. .1 to 50 wt
%, Preferably in the range of 0.5 to 30 wt%. 0.
If the amount is less than 1 wt%, sufficient twist may not be provided. If it is more than 50 wt%, the orientation may be deteriorated.

Further, as the liquid crystalline polyester used in the present invention, the polyester itself can have a uniform and monodomain twisted nematic alignment without mixing an optically active compound, and the alignment state thereof can be easily fixed. Twisted nematic liquid crystalline polyester can also be used. As the polyester, a structural unit (A),
(B) as an essential structural unit, and each structural unit such as a monool, diol, monocarboxylic acid, dicarboxylic acid or oxycarboxylic acid having an optically active group as shown below as an essential structural unit. (* Means optically active carbon).

[0116]

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Specific examples of the above structural units having an optically active group and the liquid crystalline polyesters having the structural units (A) and (B) as essential structural units include the polyesters shown below. .

[0118]

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(2e + 2f + 2g) / (2c + 3d) =
0.90 to 1.20, preferably 0.95 to 1.10,
Particularly preferably, 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.1.
0 g / (a + b + c + d + e + f + g) = 0.001-
0.30, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f + g) = 0
0.6 (a, b, c, d, e, f, and g each indicate a molar composition ratio)

[0120]

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(2e + 2f + 2g) / (2c + 3d) =
0.90 to 1.20, preferably 0.95 to 1.10,
Particularly preferably, 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.1.
0 g / (a + b + c + d + e + f + g) = 0.001-
0.30, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f + g) = 0
0.6 (a, b, c, d, e, f, and g each indicate a molar composition ratio)

[0122]

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(2f + 2g) / (2c + 2d + 3e) =
0.90 to 1.20, preferably 0.95 to 1.10,
Particularly preferably, 1.00 to 1.05 e / (c + d + e) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.
10 g / (a + b + c + d + e + f + g) = 0.001-
0.30, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f + g) = 0
0.6 (a, b, c, d, e, f, and g each indicate a molar composition ratio)

[0124]

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(2e + 2f) / (2c + 3d + 2g) =
0.90 to 1.20, preferably 0.95 to 1.10,
Particularly preferably, 1.00 to 1.05 d / (c + d + g) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.
10 g / (a + b + c + d + e + f + g) = 0.001-
0.30, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f + g) = 0
0.6 (a, b, c, d, e, f, and g each indicate a molar composition ratio)

[0126]

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(2e + 2f + g) / (2b + 2c + 3)
d) = 0.90-1.20, preferably 0.95-1.
10, particularly preferably 1.00 to 1.05 d / (b + c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.
10 g / (a + b + c + d + e + f + g) = 0.001-
0.30, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f + g) = 0
0.6 (a, b, c, d, e, f, and g each indicate a molar composition ratio)

[0128]

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(2e + 2f + 2g) / (2c + 3d) =
0.90 to 1.20, preferably 0.95 to 1.10,
Particularly preferably, 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, particularly preferably 0.02 to 0.1.
0 g / (a + b + c + d + e + f + g) = 0.001-
0.30, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f + g) = 0
0.6 (a, b, c, d, e, f, and g each indicate a molar composition ratio)

[0130]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (a + b + c + d + e + f) = 0.001-0.3
0, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, f are Shows molar composition ratio)

[0132]

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(2e + 2f) / (2c + 3d) = 0.9
0 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.05 d / (c + d) = 0.005 to 0.30, preferably 0.01 to 0.15, Particularly preferably 0.02 to 0.1
0 f / (a + b + c + d + e + f) = 0.001-0.3
0, preferably 0.005 to 0.20 a / b = 100/0 to 0/100 (a + b) / (a + b + c + d + e + f) = 0 to 0.6 (a, b, c, d, e, f are Shows molar composition ratio)

The ratio of each structural unit constituting the liquid crystalline polyester as described above cannot be unconditionally determined because the optimum value differs depending on the structure. In general, the ratio of the sum of the number of functional groups of each structural unit of monool, diol and catechol to the sum of each structural unit of monocarboxylic acid, dicarboxylic acid and trimesic acid is in the range of 0.90 to 1.20, preferably 0.1 to 1.20. 95 to 1.10, more preferably 1.0
It is in the range of 0 to 1.05. The ratio of the trimesic acid structural unit to the total of the structural units of monocarboxylic acid, dicarboxylic acid and trimesic acid is usually from 0.5 to 30.
Mol%, preferably in the range of 1.0 to 15 mol%,
More preferably, it is in the range of 2.0 to 10 mol%. The ratio of the catechol structural unit to the total of the catechol structural unit, the diol structural unit and the monol structural unit is as follows:
Usually in the range of 30 to 100 mol%, preferably 40 to 1
It is in the range of 00 mol%. The ratio of the hydroxycarboxylic acid structural unit to all structural units is from 0 to 60.
Mol%, preferably 0 to 50 mol%, more preferably 0 to 40 mol%. Further, the ratio of the optically active group in the liquid crystalline polyester is generally in the range of 0.1 to 30 mol%, preferably in the range of 0.5 to 20 mol%. The ratio of optically active groups is 0.1 mol%
If the number is smaller, there is a possibility that a twisted nematic orientation cannot be obtained. If it is more than 30 mol%,
There is a possibility that the alignment holding ability may be reduced.

The twisted nematic liquid crystalline polyester can be synthesized by a polymerization method known in the art, for example, a melt polymerization method or a solution polymerization method, similarly to the nematic liquid crystalline polyester described above.

In the case of synthesizing by a melt polymerization method, for example, a predetermined amount of trimesic acid (monomer forming the structural unit (A)), an acetylated catechol (monomer forming the structural unit (B)), for example, a diol having an optically active group , Dicarboxylic acid, monool or monocarboxylic acid, and optionally carboxylic acid (monomer forming dicarboxylic acid structural unit), acetylated diol (monomer forming diol structural unit), acetylated hydroxycarboxylic acid (hydroxycarboxylic acid structural unit) The desired twisted nematic liquid crystalline polyester can be easily obtained by copolymerizing the (forming monomer) or the like under high temperature, normal pressure, reduced pressure or high vacuum.

The charging ratio of the monomer forming each structural unit is, as described above, 0.05% of trimesic acid (monomer forming the structural unit (A)) in the polyester.
~ 15mol%, more preferably 0.10 ~ 7.5mo
l%, particularly preferably 0.20 to 5 mol%, of 4.5 to 60 m of catechols (structural unit (B) -forming monomer)
ol%, preferably 6 to 60 mol%, usually 0.1 mol of a monomer containing an optically active group (eg, an optically active diol, an optically active dicarboxylic acid, an optically active monol, an optically active monocarboxylic acid, etc.). % To 30 mol
%, Preferably 0.5 mol% to 20 mol%. The same applies to other optional components such as dicarboxylic acid (monomer forming dicarboxylic acid structural unit), diol (monomer forming diol structural unit) and hydroxycarboxylic acid (monomer forming hydroxycarboxylic acid structural unit). Sum of the number of functional groups of the unit and the catechol structural unit and the monocarboxylic acid structural unit,
The ratio of the total number of functional groups of the dicarboxylic acid structural unit to the trimesic acid structural unit is in the range of 0.90 to 1.20, preferably 0.95 to 1.10, particularly preferably 1.00 to 1.10. The ratio of the trimesic acid structural unit to the total of the monocarboxylic acid structural unit, dicarboxylic acid structural unit and trimesic acid unit is usually in the range of 0.5 to 30 mol%, preferably 1.0 to 15 mol%. , Particularly preferably 2.0 to 1
The proportion of the catechol structural unit to the total of the catechol structural unit, the monol structural unit and the diol structural unit is usually 30 to 100 mol%, preferably 40 to 10 mol%.
The range of 0 mol%, the ratio of the hydroxycarboxylic acid structural unit to the total structural units is usually in the range of 0 to 60 mol%, preferably in the range of 0 to 50 mol%, and particularly preferably in the range of 0 to 40 mol%.
Set so that it is within the range.

The polymerization conditions are not particularly limited, but are usually 150 to 350 ° C., preferably 200 to 300 ° C., and the reaction time is 30 minutes or more, preferably about 1 to 20 hours. In order to promote the polymerization reaction, for example, 1-
Amines such as methylimidazole and 4-dimethylaminopyridine, alkali metals, Fe, Mn, Ti, Co, S
Metal salts such as b and Sn may be used alone or in combination. Further, for the purpose of reducing the coloring of the polyester, various antioxidants can be added to synthesize the polyester. Further, the molecular weight of the polyester can be easily adjusted by controlling the polymerization time and the like as in the ordinary condensation reaction.

Here, the molecular weight of the liquid crystalline polyester is determined based on the phenol / tetrachloroethane mixed solvent (weight ratio 60 /
40), the value of the logarithmic viscosity measured at 30 ° C. is usually 0.0
4 to 0.4 dl / g, more preferably 0.06 to 0.3
dl / g, particularly preferably 0.1 to 0.25 dl
/ G range. When the logarithmic viscosity is less than 0.05 dl / g, the strength of the film made from the polyester becomes weak, and when the logarithmic viscosity is more than 0.4 dl / g,
The viscosity at the time of forming the liquid crystal is high, and the alignment property is reduced, and the time required for the alignment becomes longer, which is not preferable.

When the liquid crystalline polyester used in the present invention is synthesized by a solution polymerization method, for example, a predetermined amount of trimesic acid (monomer forming the structural unit (A)), dicarboxylic acid (monomer forming the dicarboxylic acid structural unit), and After converting a hydroxycarboxylic acid (a monomer for forming a hydroxycarboxylic acid structural unit) to a halide compound by allowing a chlorinating agent such as thionyl chloride to act thereon, catechols and diols dissolved in a solvent in which an acid acceptor such as pyridine is present are dissolved. By dropping and reacting at room temperature or under heating,
The desired polyester can be easily obtained. The charging ratio of each monomer is the same as in the above-mentioned melt polymerization method, and the trimesic acid derivative (the monomer forming the structural unit (A)) is 0.1%.
05 to 15 mol%, more preferably 0.10 to 7.5.
mol%, particularly preferably 0.20 to 5 mol%, of catechols (monomer forming structural unit (B)) of 4.5 to 6
0 mol%, preferably 6 to 60 mol%, a monomer containing an optically active group (eg, an optically active diol, an optically active dicarboxylic acid halide, an optically active monocarboxylic acid halide, an optically active monol, etc.) Is usually 0.1 to 30 mol%, preferably 0.5 to 20 m
ol%. The same applies to other optional components such as dicarboxylic acid (monomer forming dicarboxylic acid structural unit), diol (monomer forming diol structural unit) and hydroxycarboxylic acid (monomer forming hydroxycarboxylic acid structural unit). The ratio of the sum of the number of functional groups of the unit and the catechol structural unit to the sum of the number of functional groups of the monocarboxylic acid structural unit, the dicarboxylic acid structural unit and the trimesic acid structural unit is in the range of 0.90 to 1.20, preferably 0.1 to 1.20. The ratio of trimesic acid structural unit to monocarboxylic acid structural unit, dicarboxylic acid structural unit and trimesic acid structural unit in the total amount is usually 0 to 1.10, particularly preferably 1.00 to 1.05. In the range of 0.5 to 30 mol%, preferably in the range of 1.0 to 15 mol%, in particular The Mashiku 2.
The ratio of the catechol structural unit to the total of the catechol structural unit, the monol structural unit and the diol structural unit is usually 30 to 100 mol%, preferably 40 to 10 mol%.
The range of 0 mol%, the ratio of the hydroxycarboxylic acid structural unit to the total structural units is usually in the range of 0 to 60 mol%, preferably in the range of 0 to 50 mol%, and particularly preferably in the range of 0 to 40 mol%.
Set so that it is within the range.

The solvent used in the solution polymerization is not particularly limited. For example, halogen solvents such as o-dichlorobenzene, dichloroethane and tetrachloroethane, dimethylsulfoxide (DMSO), dimethylformamide (DMF), N-methylpyrrolidone ( Polar solvents such as NMP) and ether solvents such as tetrahydrofuran (THF) and dioxane. Examples of the acid acceptor include, but are not particularly limited to, pyridine, triethylamine, and tripropylamine.

The reaction conditions for the solution polymerization are not particularly limited, but are usually 50 to 200 ° C., preferably 60 to 200 ° C.
The reaction time at 150 ° C. is usually 1 hour or more, preferably 2 hours to 10 hours.

The liquid crystalline polyester obtained as described above has a uniform and monodomain twisted nematic alignment by itself in the liquid crystal state, and the alignment state can be easily fixed. The twisted nematic liquid crystalline polyester can be used as a twisted nematic liquid crystalline composition by blending the optically active low-molecular or high-molecular compound described above as necessary.

In the present invention, the liquid crystalline polyester described above, specifically, a composition of a nematic liquid crystalline polyester + an optically active low molecular compound, a composition of a nematic liquid crystalline polyester + an optically active high molecular compound Or a twisted nematic liquid crystalline polyester having an optically active group in the main chain is subjected to a film forming step described below. Here, the composition and the twisted nematic liquid crystalline polyester form a uniform and monodomain twisted nematic alignment in a liquid crystal state. Further, when the composition or the liquid crystalline polyester in a liquid crystal state is cooled at an arbitrary cooling rate, substantially no phase transition to a crystal phase occurs. That is, the composition or the liquid crystalline polyester provided in the present invention exhibits a monodomain twisted nematic alignment state in a liquid crystal state, and the alignment state can be easily fixed by cooling. In order to stably immobilize the twisted nematic phase, if a crystal phase is present in a lower temperature region than the twisted nematic phase in the liquid crystal phase series, the crystal phase is inevitably cooled during the immobilization. , And as a result, the twisted nematic orientation obtained once is destroyed. Liquid crystalline polyester provided for the present invention, specifically a composition of a nematic alignment polyester and an optically active low molecular or high molecular compound,
A twisted nematic liquid crystalline polyester having an optically active group in the main chain basically shows a monodomain twisted nematic phase in a liquid crystal state, and exhibits a glass state at a liquid crystal transition temperature or lower. Therefore, it is characterized in that the molecular alignment state in the liquid crystal state, that is, the twisted nematic alignment state can be maintained as it is by cooling the liquid crystal transition temperature (glass transition point) or lower. A new optical film can be manufactured by utilizing the characteristics.

In the present invention, it is desirable that the optical film is manufactured by following the alignment substrate and each step described below.

Specific examples of the alignment substrate include polyimide, polyimide amide, polyamide, polyether imide, polyether ketone, polyketone sulfide, polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polyethylene naphthalate, and the like. Plastic film substrate of polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, phenol resin, etc., the above-mentioned plastic film substrate having a rubbed surface, a glass substrate or a plastic substrate having a rubbed polyimide film or a polyvinyl alcohol film And glass such as alkali glass, borosilicate glass, flint glass, etc. Those having an anisotropic substrate like the plane is preferably used.

The optical film of the present invention can be obtained by uniformly applying the liquid crystalline polyester described above on the above-mentioned alignment substrate, and then performing a uniform alignment process and a process of fixing the alignment form. As a means for applying the liquid crystalline polyester to the alignment substrate, it can be usually performed in a solution state in which the polyester is dissolved in various solvents or in a molten state in which the polyester is melted. From the viewpoint of the production process, it is preferable to apply the solution by applying the solution obtained by dissolving the liquid crystalline polyester in a solvent.

The solution application will be described. The liquid crystalline polyester of the present invention is dissolved in a solvent to prepare a solution having a predetermined concentration. Since the thickness of the film (the thickness of the layer formed of the liquid crystalline polyester) is determined at the stage of applying the polyester to the substrate, it is necessary to precisely control the concentration, the thickness of the coating film, and the like.

The above-mentioned solvent cannot be said unconditionally because it varies depending on the composition ratio of the liquid crystalline polyester of the present invention, etc., but it is usually chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, orthodiethylene. Halogenated hydrocarbons such as chlorobenzene, phenols such as phenol and parachlorophenol,
Benzene, toluene, xylene, methoxybenzene,
Aromatic hydrocarbons such as 1,2-dimethoxybenzene, acetone, ethyl acetate, tert-butyl alcohol, glycerin, ethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, ethyl cellosolve, butyl cellosolve, 2-pyrrolidone, N-methyl-2-pyrrolidone, pyridine, treethylamine, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethylsulfoxide, acetonitrile, butyronitrile, carbon disulfide and the like, and a mixed solvent thereof such as halogenated hydrocarbons A mixed solvent with phenols is used.

The concentration of the solution cannot be determined unconditionally because it depends on the solubility of the liquid crystalline polyester to be used and finally the thickness of the intended optical film, but it is usually used in the range of 3 to 50% by weight. Preferably it is in the range of 7 to 30% by weight.

A solution of a liquid crystalline polyester adjusted to a desired concentration by using the above-mentioned solvent is then applied onto the above-described alignment substrate. As a coating method, a spin coating method, a roll coating method, a die coating method, a printing method, an immersion pulling method, a curtain coating method, or the like can be adopted.

After the application, the solvent is removed, and a layer of the composition having a uniform thickness is formed on the alignment substrate. The solvent removal conditions are:
There is no particular limitation, as long as the solvent can be substantially removed and the liquid crystalline polyester layer does not flow or run off. Usually, the solvent is removed by drying at room temperature, drying in a drying furnace, or blowing hot or hot air.

After drying, a heat treatment is carried out usually at a temperature of 50 ° C. to 300 ° C., preferably 100 ° C. to 260 ° C. to orient the liquid crystalline polyester in a liquid crystal state. The heat treatment time varies depending on, for example, the composition ratio of the liquid crystalline polyester to be used, and cannot be unconditionally determined, but is usually in the range of 10 seconds to 120 minutes, preferably 30 seconds to 60 minutes. If the time is shorter than 10 seconds, there is a possibility that uniform alignment in the liquid crystal state becomes insufficient. If the time is longer than 120 minutes, productivity may decrease, which is not desirable.

As described above, the liquid crystalline polyester can be uniformly aligned in the liquid crystal state over the entire surface of the alignment substrate.

In the present invention, in the heat treatment step, a magnetic field or an electric field may be used to uniformly align the liquid crystalline polyester.

By cooling the uniform alignment formed by the heat treatment to a temperature below the liquid crystal transition point of the polyester, the uniformity of the alignment can be fixed without any loss.

The cooling temperature is not particularly limited as long as it is lower than the liquid crystal transition point. For example, 10 ° C from the liquid crystal transition point
By cooling at a low temperature, uniform orientation can be fixed. There is no particular limitation on the cooling means, and the cooling is carried out by simply taking out from the heating atmosphere in the heat treatment step to an atmosphere below the liquid crystal transition point, for example, at room temperature. In order to increase production efficiency, forced cooling such as air cooling or water cooling or cooling may be performed. Through the above steps, the optical film of the present invention can be obtained.

The optical film may be used in such a manner that the above-mentioned oriented substrate is peeled off from the film and used as a single optical film, used as it is formed on the oriented substrate, or another substrate different from the oriented substrate. And laminating an optical film.

When used as a film alone, a method of mechanically peeling the oriented substrate at the interface with the optical film using a roll or the like, a method of mechanically peeling after dipping in a poor solvent for all structural materials, A method of peeling by applying ultrasonic waves in a poor solvent, a method of peeling by giving a temperature change using a difference in thermal expansion coefficient between the oriented substrate and the film, the oriented substrate itself, or the oriented film on the oriented substrate. A film alone is obtained by a method of dissolving and removing. Since the releasability differs depending on the composition ratio of the liquid crystalline polyester to be used and the adhesion to the alignment substrate, a method most suitable for the system should be adopted. When the optical film alone is used as an optical element, depending on the film thickness, there may be no self-supporting property, but in that case, a substrate preferable in optical properties, for example, polymethacrylate, polycarbonate, polyvinyl alcohol, polyether sulfone, polysulfone It is more desirable to use the optical film fixed on a plastic substrate such as polyarylate, polyimide, amorphous polyolefin, triacetylcellulose and the like via an adhesive or a pressure-sensitive adhesive for the strength and reliability of the optical film.

Next, a case where an optical film is used while being formed on an alignment substrate will be described. When the alignment substrate is transparent and optically isotropic, or when used as an optical element, the alignment substrate is a necessary member for the element, it can be used as a target optical element as it is.

Further, the optical film of the present invention obtained by fixing the liquid crystalline polyester on an alignment substrate can be peeled off from the substrate and laminated on another substrate more suitable for optical use. it can. That is, a laminate composed of at least an optical film and another substrate different from the alignment substrate can be incorporated into a TN-LCD or the like as an optical element, for example. Specifically, the following method can be adopted.

A substrate suitable for a target optical element (hereinafter, referred to as a substrate)
The second substrate) and the optical film on the alignment substrate,
For example, it is pasted using an adhesive or an adhesive. Next, the alignment substrate is peeled off at the interface with the optical film of the present invention, and the film is transferred to a second substrate side suitable for an optical element to obtain an optical element.

The second substrate used for the transfer is not particularly limited as long as it has an appropriate flatness.
A glass substrate or a transparent plastic film having optical isotropy is preferably used. Examples of such a plastic film include polymethyl methacrylate, polystyrene, polycarbonate, polyether sulfone, polyphenylene sulfide, polyarylate, amorphous polyolefin, triacetyl cellulose,
Epoxy resins and the like can be mentioned. Among them, polymethyl methacrylate, polycarbonate, polyarylate, polyether sulfone, triacetyl cellulose and the like are preferably used in the present invention. Further, even if it is optically anisotropic, an optically anisotropic film can be used as the second substrate if it is necessary for the optical element. Examples of the optically anisotropic film include a retardation film and a polarizing film obtained by stretching a plastic film such as polycarbonate or polystyrene.

The adhesive or pressure-sensitive adhesive for adhering the second substrate used for transfer and the optical film of the present invention is preferably of optical grade, and may be acrylic, epoxy or ethylene-vinyl acetate copolymer. , Rubber, urethane, and mixtures thereof. As the adhesive, any adhesive such as a thermosetting type, a photocuring type, and an electron beam curing type can be used without any problem as long as it has optical isotropy. The transfer of the optical film of the present invention to a second substrate suitable for an optical element includes:
After bonding the second substrate to the optical film, the alignment substrate can be peeled off at the interface with the film. Although the peeling method has been described above, a method of mechanically peeling using a roll or the like, a method of peeling by applying ultrasonic waves in a poor solvent, utilizing a difference in thermal expansion coefficient between an oriented substrate and an optical film. And a method of dissolving and removing the alignment substrate itself or the alignment film on the alignment substrate. Since the releasability depends on the composition ratio of the liquid crystalline polyester to be used and the adhesion to the alignment substrate, a method most suitable for the system should be adopted.

The optical film of the present invention has surface protection,
A protective layer such as a transparent plastic film may be provided for the purpose of increasing strength and improving environmental reliability.

Further, the optical film can be used in combination with other optical members such as a polarizing plate and a retardation film.

The optical parameters that characterize the optical film of the present invention described above include a film thickness, an in-plane retardation value, and a twist angle. Since these optical parameters vary depending on the use of the film, they cannot be unconditionally described.
m to 20 μm, preferably 0.2 μm to 10 μm
And particularly preferably in the range of 0.3 μm to 5 μm.

The in-plane retardation value was 550n.
For monochromatic light of m, it is usually in the range of 10 nm to 4000 nm, preferably in the range of 20 nm to 3500 nm, particularly preferably in the range of 30 nm to 3500 nm. Here, the in-plane retardation value in the present invention means the product of the in-plane birefringence and the film thickness.

Further, the twist angle is usually 0 ° or more and 7200 ° or more.
It is in the range of less than or equal to 20 degrees, preferably in the range of 0 to 5400 degrees (equivalent to 15 rotations), and particularly preferably in the range of 0 to 3600 degrees (equivalent to 10 rotations). In the optical film of the present invention, the direction of the director of the liquid crystal forming the film changes sequentially in the film thickness direction. Therefore, the twist angle in the optical film of the present invention is defined as the angle at which the director rotates from one surface to the other surface of the film.

The optical film of the present invention as described above is, of course, excellent in the alignment ability, easy to fix the liquid crystal alignment to glass, and excellent in the ability to maintain the liquid crystal alignment state. Therefore, various optical elements that require high-temperature durability,
For example, it can be widely used for applications such as a retardation film, a viewing angle improving film, a color compensation film, an optical rotator film, and a cholesteric polarizing plate, and its industrial utility value is extremely large.

[0171]

EXAMPLES Examples will be described below, but the present invention is not limited to these examples. In addition, each analysis method used in the Example is as follows. (1) Determination of Composition of Liquid Crystalline Polyester The polymer was dissolved in deuterated chloroform or deuterated trifluoroacetic acid, and determined by 400 MHz ¹ H-NMR (JNM-GX400 manufactured by JEOL Ltd.). (2) Measurement of logarithmic viscosity The viscosity was measured at 30 ° C. in a phenol / tetrachloroethane (60/40 weight ratio) mixed solvent using an Ubbelohde viscometer. (3) Determination of liquid crystal phase series Determined by DSC (Perkin Elmer DSC-7) measurement and observation with an optical microscope (BH2 polarizing microscope manufactured by Olympus Optical Co., Ltd.). (4) Measurement of Refractive Index The refractive index was measured with an Abbe refractometer (Type-4 manufactured by Atago Co., Ltd.). (5) Polarization analysis Ellipsometer DVA-36V manufactured by Mizojiri Optical Co., Ltd.
Performed using WLD. (6) Film thickness measurement SURFACE TEXTURE ANA manufactured by SLOAN
LYSIS SYS-TEM Dektak 3030
ST was used. In addition, interference wave measurement (manufactured by JASCO Corporation)
An ultraviolet / visible / near-infrared spectrophotometer V-570) and a method of determining the film thickness from the data of the refractive index were also used.

Example 1 p-acetoxybenzoic acid 10
0 mmol, terephthalic acid 88 mmol, trimesic acid 8 mmol, methylhydroquinone diacetate 50 mm
ol and 50 mmol of catechol diacetate were heated and stirred at 275 ° C. for 10 hours in a nitrogen stream to synthesize a polyester. The logarithmic viscosity η _inh of the obtained polyester was 0.181 dl / g. As a result of DSC measurement and observation with a polarizing microscope, as shown in Table 1, Tg had a glass phase at 110 ° C., and showed a nematic phase at a temperature higher than Tg.

This polyester and the optically active polyester shown in Table 2 were melt-mixed at a weight ratio of 95: 5 to obtain a composition, and then the phenol / tetrachloroethane (60%) containing the composition at a concentration of 15% by weight was obtained. / 40 weight ratio) A mixed solvent solution was prepared and applied by spin coating on glass having a rubbed polyimide film. 70
After drying on a hot plate at 1 ° C. for 1 hour, heat treatment was performed in a clean oven at 210 ° C. for 30 minutes. Thereafter, the film was taken out of the oven and allowed to cool naturally to obtain a polyester film 1. The thickness of the obtained film 1 is 3.8 μm
Met. Also, as a result of measuring the refractive index and the twist angle,
Birefringence Δn is 0.20, retardation is 760n
m, and the twist angle was 240 degrees. Further, the film 1 formed on the glass substrate was transparent, and it was found by observation with a polarizing microscope that the twisted nematic phase was fixed.

(Orientation Retention Ability Test) First, a polyvinyl butyral sheet was placed on a film 1 formed on a glass substrate via a rubbing polyimide film, and a glass plate was placed on the polyvinyl butyral sheet to form a sample. After keeping this sample at 80 ° C. for 30 minutes under reduced pressure,
Returned to room temperature. Then, under a pressure of 8 kgf / cm ² , T
After holding at 130 ° C., which is 20 ° C. higher than g, for 30 minutes, the pressure was returned to normal pressure and normal temperature. Place the sample between polarizing plates,
As a result of visual observation and observation with a polarizing microscope, it was confirmed that the orientation of the film 1 was not disordered and the orientation state before the test was maintained.

(Evaluation of Optical Properties of Film 1) Using a film formed on a glass substrate via a rubbing polyimide film, color compensation of the film for a super twisted nematic (hereinafter referred to as STN) liquid crystal display element. The effect was confirmed as follows.

A glass plate having the obtained film 1 on its upper surface is laminated using an adhesive on the upper surface of a 1/100 duty driven STN liquid crystal cell according to the arrangement shown in FIG.
Further, a polarizing plate was pasted thereon to produce a cell.

At this time, the directions of the upper and lower polarizing plates, the rubbing directions of the upper and lower electrode substrates, and the orientation directions of the molecules of the film 1 are as shown in FIG. That is, the twist angle of the liquid crystal molecules in the liquid crystal cell is 240 degrees, the angle between the polarization axes of the upper and lower polarizers is 90 degrees, the rubbing direction of the upper electrode substrate and the lowermost surface of the film 1 (the side in contact with the rubbing polyimide film). In ()), the angle between the orientation direction of the molecule and the rubbing direction of the lower electrode substrate is about 40 degrees.
And the twist angle of the molecules in the film 1 was set to 240 degrees opposite to the liquid crystal molecules in the liquid crystal cell.
The display color of this liquid crystal cell was black when no voltage was applied and white when voltage was applied, and a complete black and white display was realized. From the above results, it was confirmed that the film 1 was effective as an optical film having a color compensation effect.

Example 2 p-acetoxycinnamic acid 50 m
mol, 2,6-Nataphthalenedicarboxylic acid 85mmo
1, trimesic acid 10 mmol, 3,5,3 ′, 5′-
13 mmol of tetramethyl-4,4′-biphenol,
Starting from 80 mmol of 3-chlorocatechol diacetate and 7 mmol of (S) -3-methyladipic acid,
A polyester was synthesized in the same manner as in Example 1.
The properties of the obtained polyester are as shown in Table 1,
Logarithmic viscosity η _inh is 0.140 dl / g, Tg is 106 ° C
And a twisted nematic phase at a temperature higher than Tg.

Phenol / tetrachloroethane containing this polyester at a concentration of 17% by weight (60/40 weight ratio)
A mixed solvent solution was prepared. Using this solution, a film 2 having a twisted nematic orientation fixed on a glass plate via a rubbing polyimide film under the conditions shown in Table 2 was produced.

Using the obtained film 2, an orientation retention ability test was conducted in the same manner as in Example 1. As a result, no disturbance in orientation was observed, and it was confirmed that the orientation state before the test was retained. .

Further, when the color compensation effect on the STN liquid crystal display element was confirmed in the same manner as in Example 1, it was found that perfect black and white display was obtained. From the above, it was confirmed that the film 2 was effective as an optical film having a color compensation effect.

[Examples 3 to 7] Polyesters shown in Table 1 were synthesized according to Examples 1 and 2 to prepare films. As in Examples 1 and 2, the obtained films were tested for alignment retention ability and for the presence or absence of the color compensation effect of the STN liquid crystal display device. The results are shown in Table 2.

Example 8 100 mmol of 6-acetoxy-2-naphthoic acid, 40 mmol of isophthalic acid, 45 mmol of terephthalic acid, 10 mmol of trimesic acid, 50 mmol of resorcinol diacetate, 3-tert
Using 50 mmol of -butylcatechol diacetate as a raw material, a polyester was synthesized in the same manner as in Example 1. The logarithmic viscosity η _inh of the obtained polyester is 0.14.
0 dl / g, Tg has a glass phase at 121 ° C.
At a temperature higher than Tg, a nematic phase was exhibited.

Next, the obtained polyester and the optically active polyester shown in Table 3 were melt-mixed at a weight ratio of 98: 2 to obtain a composition.
% Of dimethylacetamide solution was prepared. This solution was applied by a curtain coating method on a glass substrate having a rubbed polyimide film. After applying, 7
After drying for 1 hour on a hot plate at 0 ° C, 220 ° C
In a clean oven for 30 minutes. afterwards,
The film 8 was taken out of the oven and allowed to cool naturally to obtain a film 8 on a glass substrate via a rubbing polyimide film. The thickness of the film 8 was 4.9 μm. Further, as a result of measuring the refractive index and the twist angle, the birefringence Δn was 0.22, the retardation was 1080 nm, and the twist angle was 90 degrees. Further, the obtained film 8 was transparent, and as a result of observation with a polarizing microscope, it was confirmed that the twisted nematic orientation was fixed.

Next, a film 8 was subjected to an orientation retention ability test in the same manner as in Example 1. As a result, it was confirmed that the orientation state before the test was retained without any disorder of orientation.

Next, two polarizing plates were arranged above and below the film 8 in paranicol and crossed Nicol, and the transmission spectrum of each was measured. As a result, it was found that when arranged in paranicol, the transmittance was almost 0% over a wide range of the visible light region, and in the case of crossed Nicols, the transmittance was about 80% (FIG. 3). From the above results, it was confirmed that the film 8 was effective as an optical film having characteristics as a 90-degree optical rotator.

Example 9 p-acetoxycinnamic acid 100
mmol, terephthalic acid 87 mmol, 1,4-cyclohexanehexane dicarboxylic acid 10 mmol, trimesic acid 2 m
mol. Using 95 mmol of 3-tert-butylcatechol diacetate and 5 mmol of (S) -2-methyl-1,4-butanediol as raw materials, a polyester was synthesized in the same manner as in Example 1. The obtained polyester had a logarithmic viscosity η _inh of 0.124 and a Tg of 95 ° C. and had a glass phase, and showed a twisted nematic phase at a temperature higher than Tg.

A dimethylformamide solution having a polyester concentration of 17% by weight was prepared. Using this solution, a film 9 having a twisted nematic orientation fixed on a glass substrate via a rubbing polyimide film under the conditions shown in Table 3
Was prepared.

The film 9 was subjected to the orientation retention ability test in the same manner as in Example 1. As a result, it was confirmed that the orientation was not disordered and the orientation state before the test was retained.

The transmission spectrum of the film 9 was measured in the same manner as in Example 8 by arranging the film in paranicol and crossed Nicol. As a result, it was confirmed that the film 9 was effective as an optical film having characteristics as a 90-degree optical rotator.

Example 10 According to Examples 1 and 2, the polyesters shown in Table 1 were synthesized to form films. As in Examples 8 and 9, the obtained films were tested for orientation retention ability and the presence or absence of characteristics as a 90-degree optical rotator. The results are shown in Table 2.

Comparative Example 1 p-acetoxybenzoic acid 10
Using 0 mmol, terephthalic acid 100 mmol, methylhydroquinone diacetate 50 mmol and catechol diacetate 50 mmol as raw materials, a polyester was synthesized in the same manner as in Example 1. The logarithmic viscosity η _inh of the obtained polyester is 0.178 dl / g, and the Tg is 1
It had a glass phase at 07 ° C. and showed a nematic phase at temperatures higher than Tg.

The obtained polyester and the optically active polyester shown in Table 2 were melt-mixed at a weight ratio of 96: 4 to obtain a composition, and the phenol / tetrachloroethane containing the composition at a concentration of 15% by weight was obtained. (Weight ratio: 60/4
0) A mixed solvent solution was prepared. This solution was applied by spin coating to a glass substrate having a rubbed polyimide film. After drying on a 70 ° C. hot plate for 1 hour, heat treatment was performed in a 210 ° C. clean oven for 30 minutes. Thereafter, the film was taken out of the oven and allowed to cool naturally to obtain Comparative Film 1. The thickness of the film is 3.
It was 7 μm. As a result of measuring the refractive index and the torsion angle, the birefringence index Δn was 0.21, and the retardation was 77.
0 nm, and the twist angle was 241 degrees. Further, the comparative film 1 formed on the glass substrate was transparent, and as a result of observation with a polarizing microscope, it was found that the twisted nematic phase was fixed. As a result of performing an alignment holding ability test using the comparative film 1 in the same manner as in Example 1, it was found that the alignment was disordered and the alignment holding ability was not found.

Comparative Example 2 The polyesters shown in Table 1 were synthesized according to Example 2. Using this polyester,
A comparative film 2 having a twisted nematic phase fixed thereon was produced in the same manner as in Example 2. Using the obtained comparative film 2, an orientation retention ability test was performed in the same manner as in Example 1. As a result, it was found that the orientation was disordered and the orientation retention ability was not found.

[Comparative Example 3] Polyesters shown in Table 1 were synthesized according to Example 1. Polyester obtained and Table 3
Was melt-mixed at a weight ratio of 98: 2 to obtain a composition.
A dimethylacetamide solution containing 0 wt% was prepared.
Using this solution, a comparative film 3 having a twisted nematic phase fixed thereon was obtained in the same manner as in Example 8. Using the obtained comparative film 3, an orientation retention test was performed in the same manner as in Example 1. As a result, it was found that the orientation was disordered and the orientation retention capability was absent.

[Comparative Example 4] Polyesters shown in Table 1 were synthesized according to Example 2. Next, a dimethylformamide solution containing the obtained polyester at a concentration of 17 wt% was prepared. Using this solution, a comparative film 4 was produced in the same manner as in Example 9. Using the obtained comparative film 4, an orientation retention ability test was carried out in the same manner as in Example 1. As a result, it was found that the orientation was disordered and the orientation retention ability was absent.

[0197]

[Table 1]

[0198]

[Table 2]

[0199]

[Table 3]

[0200]

[Table 4]

[0201]

[Table 5]

[0202]

[Table 6]

[0203]

[Table 7]

[0204]

[Table 8]

[0205]

[Table 9]

[0206]

[Table 10]

1) In the table, the numbers beside the structural units represent the molar composition ratios. 2) In the phase series, I represents an isotropic phase, N represents a nematic phase, N ^* represents a twisted nematic phase, and g represents a glass phase. 3) In the color compensation effect, ◎ indicates that the effect was obtained. 4) In optical rotation, ◎ indicates that the effect was obtained. 5) The orientation retention test is a result of visually observing the disorder of the orientation state after holding for 30 minutes at a temperature of 20 ° C. higher than Tg under a pressure of 8 kgf / cm ² . A: The orientation was maintained. X: The orientation was disordered.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal cell used in an embodiment of the present invention. However, the layer of the pressure-sensitive adhesive used for bonding each layer is omitted.

FIG. 2 shows the mutual relationship of each axis of a material constituting a liquid crystal cell used in an embodiment of the present invention.

FIG. 3 shows transmission spectra under paranicol and crossed Nicols in Example 8 of the present invention.

[Explanation of symbols]

 Reference Signs List 1 upper polarizing plate 2 color compensator (optical film and substrate) 3 liquid crystal cell 4 lower polarizing plate 5 polarization axis direction of lower polarizing plate 6 rubbing direction of lower electrode substrate of liquid crystal cell 7 rubbing direction of upper electrode substrate of liquid crystal cell 8 Lowermost molecular orientation direction of optical film 9 Uppermost molecular orientation direction of optical film 10 Polarization axis direction of upper polarizer 11 Twist angle of liquid crystal molecules in liquid crystal cell 12 Twist of molecules in optical film 13 7 and 8 Angle between 14 Angle between 5 and 6

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C08L 67/00 C08L 67/00

Claims (3)

[Claims] 1. Structural units (A) and (B) shown below
As an essential structural unit, exhibits a glassy state at a temperature lower than the liquid crystal transition point, and has a logarithmic viscosity η measured at 30 ° C. in a phenol / tetrachloroethane mixed solvent (weight ratio of 60/40) of 0.04 to An optical film, which is substantially formed of a liquid crystal material having a liquid crystal state of 0.4 dl / g and having a twisted nematic alignment in a liquid crystal state as an essential component. Embedded image X independently represents O or C = O. Y represents a group independently selected from F, Cl, Br and an alkyl group having 1 to 4 carbon atoms. Further, n is 0 or 1. 2. The optical film according to claim 1, wherein the liquid crystalline substance is a twisted nematic liquid crystalline polyester having an optically active group in a molecule of the liquid crystalline polyester. 3. The optical film according to claim 1, wherein the liquid crystal substance is a composition substantially comprising a liquid crystal polyester and an optically active compound, and the liquid crystal polyester is a nematic liquid crystal polyester.