JPH09222511A - Production of compensator for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce a compensator for a liquid crystal display element having excellent thermal stability and reliability at high temp. SOLUTION: A planer condensed cyclic compd. having six or more phenyl- type hydroxyl groups in one molecule, an acetylating agent, and several kinds of carboxylic compds. having >6 carbon atoms are supplied to a reaction system to cause acetylation reaction of the phenyl-type hydroxyl groups, while the reaction between the acetyl groups obtd. by the first reaction and the carboxylic compds. present in the reaction system is made to proceed to release acetic acid in the same reaction system. The obtd. reaction product is used as the substantial component of a discotic liquid crystal material, which is applied on a counter substrate, heat treated and cooled to obtain a compensator for a liquid crystal display element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a viewing angle improving plate (viewing angle compensating plate) for a liquid crystal display and a compensating plate useful for a color compensating plate, which is excellent in thermal stability and high temperature reliability. Regarding

[0002]

2. Description of the Related Art Recently, discotic liquid crystal compounds are
JP-A-56-90878, JP-A-2-287120
No. 7-134213, 7-14640
It has been clarified that it is useful as a chemical material for various optical elements as disclosed in Japanese Patent Laid-Open No. 9 and the like.
The liquid crystal compound is mainly composed of a disc-shaped central portion (discogen) essential for expressing a discotic liquid crystal phase and a substituent necessary for stabilizing the liquid crystal phase,
A liquid crystal compound in which an ester bond is formed between a discogen having a phenolic hydroxyl group and a substituent having a carboxylic acid group (carboxyl group) is used as an optical material. Conventional ester bond formation method is
For example, 2,3,6 as raw materials that can become discogens
A compound having a plurality of phenolic hydroxyl groups in one molecule such as 7,10,11-hexahydroxytriphenylene and a chloride of a carboxylic acid as a raw material which can be a substituent part are used to condense these. However, in this method, it is necessary to convert a carboxylic acid into a chloride by using a reagent which is harmful and difficult to handle, such as thionyl chloride, and a post-treatment is complicated because a solvent and a base are required during the condensation reaction. However, it has been impossible to mass-produce industrially a discotic liquid crystal compound by this method. Further, the compensator described in the above publication is oriented as a director by tilting a director (a unit vector that specifies the orientation direction of the average optical axis of a molecule) of discotic liquid crystal molecules in a certain direction. The compensator has a negative uniaxial property in which the optical axis is tilted, that is, the refractive index structure is tilted. In this compensator, a SiO oblique vapor deposition film and a special metamorphic alignment film are used to obtain an alignment in which the optical axis is tilted. There are manufacturing disadvantages such as the use, which cause a high cost.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above problems and found that the reaction product itself obtained by a simple and efficient reaction becomes a discotic liquid crystal material having excellent characteristics. Has reached the present invention.

[0004]

Means for Solving the Problems That is, the first aspect of the present invention
Is one or more planar condensed ring compounds having 6 or more phenolic hydroxyl groups in one molecule, an acetylating agent and a plurality of carboxylic acid compounds having 6 or more carbon atoms, A reaction product produced by causing an acetylation reaction of a phenolic hydroxyl group and advancing a deacetic acid reaction between the acetyl group obtained by the reaction and a carboxylic acid compound coexisting in the reaction system in the same reaction system. A discotic liquid crystal material consisting essentially of a material is applied onto the alignment substrate and then heat treated,
The present invention relates to a method for manufacturing a compensating plate for a liquid crystal display element, which is characterized by cooling. A second aspect of the present invention is that the discotic liquid crystal material comprises one or more planar condensed ring compounds having 6 or more phenolic hydroxyl groups in one molecule, an acetylating agent, and a plurality of carbon atoms having 6 or more carbon atoms. In the reaction with one kind of carboxylic acid compound, in the reaction time described below from 1/3 to 9/10 of the total reaction time from the reaction start time to the reaction end time, the reaction conditions are under reduced pressure or under an inert gas stream. The present invention relates to a method for producing a compensating plate for a liquid crystal display element, which is substantially composed of a reaction product obtained by carrying out a reaction. The third aspect of the present invention is that the planar condensed ring compound having 6 or more phenolic hydroxyl groups in one molecule is 2, 3,
6,7,10,11-Hexahydroxytriphenylene The present invention relates to a method for manufacturing a compensating plate for a liquid crystal display element according to the first or second aspect. The fourth aspect of the present invention is that a plurality of carboxylic acid compounds having 6 or more carbon atoms are
Compounds having one carboxyl group in the molecule and /
Alternatively, the present invention relates to a method for producing a compensating plate for a liquid crystal display element, which is a carboxylic acid compound having two or more carboxyl groups in one molecule. Further, a fifth aspect of the present invention relates to the method for producing a compensating plate for a liquid crystal display element according to any one of the first to fourth aspects, wherein the acetylating agent is acetic anhydride.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The discotic liquid crystal material used in the method for producing a compensating plate for a liquid crystal display device of the present invention is one or more planes having 6 or more phenolic hydroxyl groups in one molecule. Substantially composed of a reaction product obtained by reacting a condensed ring compound, an acetylating agent and a plurality of carboxylic acid compounds having 6 or more carbon atoms. The reaction product contains one or more discotic liquid crystal compounds, and is preferably substantially composed of two or more discotic liquid crystal compounds. The discotic liquid crystal compound produced in the reaction product is a liquid crystal compound in which only a monofunctional substituent is introduced, and a polyfunctional substituent such as a difunctional or trifunctional substituent is introduced into a discogen. There is an oligomerized discotic liquid crystal compound such as a produced dimer or trimer. Further, a product other than the discotic liquid crystal compound may be produced depending on the reaction conditions, the kind of the planar condensed ring compound, the acetylating agent and / or the carboxylic acid compound used in the reaction.

The present invention will be described in more detail below. The planar condensed ring compound having 6 or more phenolic hydroxyl groups in one molecule, which is used in the production method of the present invention, is mainly a disc-shaped central portion (disco) essential for expressing a discotic liquid crystal phase. (Gen) is a compound that constitutes. In addition, the planar condensed ring compound means a compound that can be planar in terms of molecular structure, in which at least three aromatic rings are condensed.

Examples of the planar condensed ring compound having a phenolic hydroxyl group in the present invention include compounds having a triphenylene skeleton, a torquesen skeleton, and the like. In the present invention, among them, 2, 3, 6, 7, 10,
11-hexahydroxytriphenylene (hereinafter referred to as HHT
(Abbreviated as P) can be mentioned as a particularly preferred compound.

On the other hand, a plurality of kinds of carboxylic acid compounds having 6 or more carbon atoms are used as the compound constituting the substituent portion necessary for stabilizing the discotic liquid crystal phase. In the present invention, the acetylation reaction of the planar condensed ring compound is caused, and the acetyl group obtained by the reaction is
A deacetic acid reaction is caused with a carboxylic acid compound coexisting in the reaction system, whereby the carboxylic acid compound is introduced into the planar condensed ring compound.

As the above-mentioned carboxylic acid compound, a monofunctional carboxylic acid having one carboxyl group in one molecule,
Alternatively, both of the polyfunctional carboxylic acid compounds having two or more carboxyl groups in one molecule are preferably used.

Examples of the monofunctional carboxylic acid include hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, Examples thereof include alkanoic acids or alkenoic acids having 6 to 40 carbon atoms, preferably 6 to 30 carbon atoms, such as nonadecanoic acid, eicosanoic acid, oleic acid, linolenic acid, cyclohexanecarboxylic acid and cyclopentanecarboxylic acid.

Further, a benzoic acid derivative having 7 to 37 carbon atoms, preferably 7 to 27 carbon atoms can also be preferably used. Examples thereof are shown below, but an alkyl group, an alkoxy group, a halogen,
When using a benzoic acid having a substituent such as an amino group and a nitro group, the position of substitution is not particularly limited, and
It can be suitably used at any of the substitution positions at the 3 and 4 positions. A compound having a plurality of substituents can also be used.

Specific examples thereof include benzoic acid and 4-
Methylbenzoic acid, 4-ethylbenzoic acid, 4-propylbenzoic acid, 4-isopropylbenzoic acid, 4-butylbenzoic acid, 4-sec-butylbenzoic acid, 4-isobutylbenzoic acid, 4-tert-butylbenzoic acid, 4-pentylbenzoic acid, 4-hexylbenzoic acid, 4-heptylbenzoic acid, 4-octylbenzoic acid, 4-nonylbenzoic acid, 4-
Decylbenzoic acid, 4-undecylbenzoic acid, 4-dodecylbenzoic acid, 4-tridecylbenzoic acid, 4-tetradecylbenzoic acid, 4-chlorobenzoic acid, 4-bromobenzoic acid, 4-nitrobenzoic acid, 4-dimethylamino Benzoic acid, 4-hydroxybenzoic acid, 4-methoxybenzoic acid,
4-ethoxybenzoic acid, 4-propoxybenzoic acid, 4-
Isopropoxybenzoic acid, 4-butoxybenzoic acid, 4-
sec-Butoxybenzoic acid, 4-isobutoxybenzoic acid, 4-tert-butoxybenzoic acid, 4-pentyloxybenzoic acid, 4-hexyloxybenzoic acid, 4-heptyloxybenzoic acid, 4-octyloxybenzoic acid, 4
-Nonyloxybenzoic acid, 4-decyloxybenzoic acid,
4-undecyloxybenzoic acid, 4-dodecyloxybenzoic acid, 4-tridecyloxybenzoic acid, 4-tetradecyloxybenzoic acid, 3-methylbenzoic acid, 3-ethylbenzoic acid, 3-propylbenzoic acid, 3 -Isopropylbenzoic acid, 3-butylbenzoic acid, 3-sec-butylbenzoic acid, 3-isobutylbenzoic acid, 3-tert-butylbenzoic acid, 3-pentylbenzoic acid, 3-hexylbenzoic acid, 3-heptylbenzoic acid , 3-octylbenzoic acid, 3
-Nonylbenzoic acid, 3-decylbenzoic acid, 3-undecylbenzoic acid, 3-dodecylbenzoic acid, 3-tridecylbenzoic acid, 3-tetradecylbenzoic acid, 3-chlorobenzoic acid, 3-bromobenzoic acid, 3-nitro Benzoic acid, 3-dimethylaminobenzoic acid, 3-hydroxybenzoic acid, 3-
Methoxybenzoic acid, 3-ethoxybenzoic acid, 3-propoxybenzoic acid, 3-isopropoxybenzoic acid, 3-butoxybenzoic acid, 3-sec-butoxybenzoic acid, 3-isobutoxybenzoic acid, 3-tert-butoxybenzoic acid , 3-pentyloxybenzoic acid, 3-hexyloxybenzoic acid, 3-heptyloxybenzoic acid, 3-octyloxybenzoic acid, 3-nonyloxybenzoic acid, 3-decyloxybenzoic acid, 3-undecyloxybenzoic acid, 3
-Dodecyloxybenzoic acid, 3-tridecyloxybenzoic acid, 3-tetradecyloxybenzoic acid, 2-methylbenzoic acid, 2-ethylbenzoic acid, 2-propylbenzoic acid,
2-Isopropylbenzoic acid, 2-butylbenzoic acid, 2-
sec-Butylbenzoic acid, 2-isobutylbenzoic acid, 2
-Tert-butylbenzoic acid, 2-pentylbenzoic acid,
2-hexylbenzoic acid, 2-heptylbenzoic acid, 2-octylbenzoic acid, 2-nonylbenzoic acid, 2-decyl

Benzoic acid, 2-undecylbenzoic acid, 2-
Dodecylbenzoic acid, 2-tridecylbenzoic acid, 2-tetradecylbenzoic acid, 2-chlorobenzoic acid, 2-bromobenzoic acid, 2-nitrobenzoic acid, 2-dimethylaminobenzoic acid, 2-hydroxybenzoic acid, 2-methoxy. Benzoic acid, 2-ethoxybenzoic acid, 2-propoxybenzoic acid,
2-isopropoxybenzoic acid, 2-butoxybenzoic acid,
2-sec-butoxybenzoic acid, 2-isobutoxybenzoic acid, 2-tert-butoxybenzoic acid, 2-pentyloxybenzoic acid, 2-hexyloxybenzoic acid, 2-heptyloxybenzoic acid, 2-octyloxybenzoic acid,
2-nonyloxybenzoic acid, 2-decyloxybenzoic acid, 2-undecyloxybenzoic acid, 2-dodecyloxybenzoic acid, 2-tridecyloxybenzoic acid, 2-tetradecyloxybenzoic acid, 3,4-dimethoxybenzoic acid 3,4-diethoxybenzoic acid, 3,4-dipropoxybenzoic acid, 3,4-dibutoxybenzoic acid, 3,4-dipentyloxybenzoic acid, 3,4-dihexyloxybenzoic acid, 3,4-diheptyloxy Benzoic acid, 3,4-
Dioctyloxybenzoic acid, 3,4-dinonyloxybenzoic acid, 3,4-didecyloxybenzoic acid, 3,4-bis (2-methoxyethoxy) benzoic acid, 2,4-dimethoxybenzoic acid, 2,4-diethoxybenzoic acid , 2,4-
Dipropoxybenzoic acid, 2,4-dibutoxybenzoic acid,
2,4-dipentyloxybenzoic acid, 2,4-dihexyloxybenzoic acid, 2,4-diheptyloxybenzoic acid, 2,4-dioctyloxybenzoic acid, 2,4-dinonyloxybenzoic acid, 2,4-didecyloxy Benzoic acid, 2,4-bis (2-methoxyethoxy) benzoic acid,
3,4,5-Trimethoxybenzoic acid, 3,4,5-Triethoxybenzoic acid, 3,4,5-Tripropoxybenzoic acid, 3,4,5-Tributoxybenzoic acid, 3,4,5-
Tripentyloxybenzoic acid, 3,4,5-trihexyloxybenzoic acid, 3,4,5-triheptyloxybenzoic acid, 3,4,5-trioctyloxybenzoic acid,
3,4,5-Trinonyloxybenzoic acid, 3,4,5-
Tridecyloxybenzoic acid, 4-methyl-3-methoxybenzoic acid, 4-ethyl-3-methoxybenzoic acid, 4-propyl-3-methoxybenzoic acid, 4-butyl-3-methoxybenzoic acid, 4-pentyl- 3-methoxybenzoic acid,
4-hexyl-3-methoxybenzoic acid, 4-heptyl-
3-methoxybenzoic acid, 4-octyl-3-methoxybenzoic acid, 4-nonyl-3-methoxybenzoic acid, 4-decyl-3-methoxybenzoic acid, 4-undecyl-3-methoxybenzoic acid, 4-dodecyl- 3-methoxybenzoic acid,
3-Methyl-4-methoxybenzoic acid, 3-ethyl-4-
Methoxybenzoic acid, 3-propyl-4-methoxybenzoic acid, 3-butyl-4-methoxybenzoic acid, 3-pentyl-4-methoxybenzoic acid, 3-hexyl-4-methoxybenzoic acid, 3-heptyl-4- Methoxybenzoic acid, 3-
Octyl-4-methoxybenzoic acid, 3-nonyl-4-methoxybenzoic acid, 3-decyl-4-methoxybenzoic acid,
Examples include 3-undecyl-4-methoxybenzoic acid and 3-dodecyl-4-methoxybenzoic acid.

Further, a cinnamic acid derivative having 9 to 39 carbon atoms, preferably 9 to 29 carbon atoms can also be preferably used. Examples thereof will be shown below, but when cinnamic acid having a substituent such as an alkyl group, an alkoxy group, a halogen, an amino group or a nitro group is used, the substitution position is not particularly limited, and the 2,3,4 position Any substitution position can be preferably used. A compound having a plurality of substituents can also be used.

Specific examples thereof include cinnamic acid, 4-methylcinnamic acid, 4-ethylcinnamic acid, 4-propylcinnamic acid,
4-Isopropylcinnamic acid, 4-butylcinnamic acid, 4-se
c-Butylcinnamic acid, 4-isobutylcinnamic acid, 4-ter
t-Butyl cinnamic acid, 4-pentyl cinnamic acid, 4-hexyl cinnamic acid, 4-heptyl cinnamic acid, 4-octyl cinnamic acid, 4
-Nonylcinnamic acid, 4-decylcinnamic acid, 4-undecylcinnamic acid, 4-dodecylcinnamic acid, 4-tridecylcinnamic acid, 4
-Tetradecylcinnamic acid, 4-chlorocinnamic acid, 4-bromocinnamic acid, 4-nitrocinnamic acid, 4-dimethylaminocinnamic acid, 4-hydroxycinnamic acid, 4-methoxycinnamic acid, 4-
Ethoxycinnamic acid, 4-propoxycinnamic acid, 4-isopropoxycinnamic acid, 4-butoxycinnamic acid, 4-sec-butoxycinnamic acid, 4-isobutoxycinnamic acid, 4-tert-
Butoxycinnamic acid, 4-pentyloxycinnamic acid, 4-hexyloxycinnamic acid, 4-heptyloxycinnamic acid, 4-octyloxycinnamic acid, 4-nonyloxycinnamic acid, 4-decyloxycinnamic acid, 4-undecyloxycinnamic acid Acid, 4-
Dodecyloxycinnamic acid, 4-tridecyloxycinnamic acid,
4-tetradecyloxycinnamic acid, 3-methylcinnamic acid, 3
-Ethyl cinnamic acid, 3-propyl cinnamic acid, 3-isopropyl cinnamic acid, 3-butyl cinnamic acid, 3-sec-butyl cinnamic acid, 3-isobutyl cinnamic acid, 3-tert-butyl cinnamic acid, 3-pentyl cinnamic acid , 3-hexyl cinnamic acid, 3-heptyl cinnamic acid, 3-octyl cinnamic acid, 3-nonyl cinnamic acid, 3-decyl cinnamic acid, 3-undecyl cinnamic acid, 3-dodecyl cinnamic acid, 3-tridecyl cinnamic acid, 3 -Tetradecylcinnamic acid, 3-chlorocinnamic acid, 3-bromocinnamic acid, 3-
Nitrocinnamic acid, 3-dimethylaminocinnamic acid, 3-hydroxycinnamic acid, 3-methoxycinnamic acid, 3-ethoxycinnamic acid, 3-propoxycinnamic acid, 3-isopropoxycinnamic acid, 3-butoxycinnamic acid, 3- sec-Butoxycinnamic acid, 3-isobutoxycinnamic acid, 3-tert-butoxycinnamic acid, 3-pentyloxycinnamic acid, 3-hexyloxycinnamic acid, 3-heptyloxycinnamic acid, 3-octyloxycinnamic acid, 3- Nonyloxycinnamic acid, 3-decyloxycinnamic acid, 3-undecyloxycinnamic acid, 3-dodecyloxycinnamic acid, 3-tridecyloxycinnamic acid, 3-tetradecyloxycinnamic acid, 2-methylcinnamic acid, 2-ethyl Cinnamic acid, 2-propylcinnamic acid, 2-isopropylcinnamic acid, 2-butylcinnamic acid, 2-sec-butylcinnamic acid, 2
-Isobutyl cinnamic acid, 2-tert-butyl cinnamic acid, 2
-Pentyl cinnamic acid, 2-hexyl cinnamic acid, 2-heptyl cinnamic acid, 2-octyl cinnamic acid, 2-nonyl cinnamic acid, 2-
Decylcinnamic acid, 2-undecylcinnamic acid, 2-dodecylcinnamic acid, 2-tridecylcinnamic acid, 2-tetradecylcinnamic acid, 2-chlorocinnamic acid, 2-bromocinnamic acid, 2-nitrocinnamic acid, 2-dimethylamino Cinnamic acid, 2-hydroxycinnamic acid, 2-methoxycinnamic acid, 2-ethoxycinnamic acid, 2-
Propoxycinnamic acid, 2-isopropoxycinnamic acid, 2-butoxycinnamic acid, 2-sec-butoxycinnamic acid, 2-isobutoxycinnamic acid, 2-tert-butoxycinnamic acid, 2-
Pentyloxycinnamic acid, 2-hexyloxycinnamic acid, 2
-Heptyloxycinnamic acid, 2-octyloxycinnamic acid,
2-nonyloxycinnamic acid, 2-decyloxycinnamic acid, 2
-Undecyloxycinnamic acid, 2-dodecyloxycinnamic acid, 2-tridecyloxycinnamic acid, 2-tetradecyloxycinnamic acid, 3,4-dimethoxycinnamic acid, 3,4-diethoxycinnamic acid, 3,4- Dipropoxycinnamic acid, 3,4-
Dibutoxycinnamic acid, 3,4-dipentyloxycinnamic acid,
3,4-dihexyloxycinnamic acid, 3,4-diheptyloxycinnamic acid, 3,4-dioctyloxycinnamic acid, 3,
4-dinonyloxycinnamic acid, 3,4-didecyloxycinnamic acid, 3,4-bis (2-methoxyethoxy) cinnamic acid,
2,4-dimethoxycinnamic acid, 2,4-diethoxycinnamic acid, 2,4-dipropoxycinnamic acid, 2,4-dibutoxycinnamic acid, 2,4-dipentyloxycinnamic acid, 2,4-dihexyloxycinnamic acid, 2,4-diheptyloxycinnamic acid, 2,4-dioctyloxycinnamic acid, 2,4-dinonyloxycinnamic acid, 2,4-didecyloxycinnamic acid, 2,
4-bis (2-methoxyethoxy) cinnamic acid, 3,4,5
-Trimethoxycinnamic acid, 3,4,5-triethoxycinnamic acid, 3,4,5-tripropoxycinnamic acid, 3,4,5-
Tributoxycinnamic acid, 3,4,5-tripentyloxycinnamic acid, 3,4,5-trihexyloxycinnamic acid, 3,
4,5-Triheptyloxycinnamic acid, 3,4,5-trioctyloxycinnamic acid, 3,4,5-trinonyloxycinnamic acid, 3,4,5-tridecyloxycinnamic acid, 4-methyl- 3-methoxycinnamic acid, 4-ethyl-3-methoxycinnamic acid, 4-propyl-3-methoxycinnamic acid, 4-butyl-3-methoxycinnamic acid, 4-pentyl-3-methoxycinnamic acid, 4-hexyl- 3-methoxycinnamic acid, 4-heptyl-3-methoxycinnamic acid, 4-octyl-3-methoxycinnamic acid, 4-nonyl-3-methoxycinnamic acid, 4-decyl-3-methoxycinnamic acid, 4-undecyl- 3-methoxycinnamic acid, 4-dodecyl-3-methoxycinnamic acid, 3-methyl-4-methoxycinnamic acid, 3-ethyl-4-methoxycinnamic acid, 3-propyl-4-methoxycinnamic acid, 3-butyl- 4-methoxy Cinnamic acid, 3-pentyl-4-methoxycinnamic acid, 3-hexyl-4-methoxycinnamic acid, 3-heptyl-4-methoxycinnamic acid, 3-octyl-4-methoxycinnamic acid, 3-nonyl-4-methoxy. Examples include cinnamic acid, 3-decyl-4-methoxycinnamic acid, 3-undecyl-4-methoxycinnamic acid, and 3-dodecyl-4-methoxycinnamic acid.

The carboxylic acid has 11 to 4 carbon atoms.
A 1-naphthoic acid derivative can also be preferably used. Alkyl group,
When a naphthoic acid derivative having a substituent such as an alkoxy group, a halogen, an amino group or a nitro group is used, the substitution position is not particularly limited, and all isomers can be preferably used, but especially at the 2-position. In addition, a carboxyl group and a substituent bonded to the 6-position or 7-position, preferably the 6-position, can be preferably used for reasons such as easy availability.

Specific examples thereof include 2-naphthoic acid, 6-methyl-2-naphthoic acid, 6-ethyl-2-naphthoic acid, 6-propyl-2-naphthoic acid and 6-isopropyl-2-naphthoic acid. , 6-butyl-2-naphthoic acid, 6-sec-butyl-2-naphthoic acid, 6-isobutyl-2-naphthoic acid, 6-6-tert-butyl-2
-Naphthoic acid, 6-pentyl-2-naphthoic acid, 6-hexyl-2-naphthoic acid, 6-heptyl-2-naphthoic acid, 6-octyl-2-naphthoic acid, 6-nonyl-2-
Naphthoic acid, 6-decyl-2-naphthoic acid, 6-undecyl-2-naphthoic acid, 6-dodecyl-2-naphthoic acid, 6-6-tridecyl-2-naphthoic acid, 6-tetradecyl-2-naphthoic acid, 6-chloro-2-naphthoic acid, 6-bromo-2-naphthoic acid, 6-nitro-2-naphthoic acid, 6-dimethylamino-2-naphthoic acid, 6-
Hydroxy-2-naphthoic acid, 6-methoxynaphthoic acid, ethoxy-2-naphthoic acid, 6-propoxy-2-
Naphthoic acid, 6-isopropoxy-2-naphthoic acid, 6
-Butoxy-2-naphthoic acid, 6-sec-butoxy-
2-naphthoic acid, 6-isobutoxy-2-naphthoic acid,
6-tert-butoxy-2-naphthoic acid, 6-pentyloxy-2-naphthoic acid, 6-hexyloxy-2-
Naphthoic acid, 6-heptyloxy-2-naphthoic acid, 6
-Octyloxy-2-naphthoic acid, 6-nonyloxy-2-naphthoic acid, 6-decyloxy-2-naphthoic acid, 6-undecyloxy-2-naphthoic acid, 6-dodecyloxy-2-naphthoic acid, 6- Tridecyloxy-
Examples thereof include 2-naphthoic acid and 6-tetradecyloxy-2-naphthoic acid.

Further, as the carboxylic acid, a [1,1'-biphenyl] carboxylic acid derivative can also be preferably used. When a [1,1′-biphenyl] carboxylic acid derivative having a substituent such as an alkyl group, an alkoxy group, a halogen, an amino group or a nitro group is used, the substitution position is not particularly limited, and all isomers are It can be preferably used, but especially 4
A carboxyl group at the 4-position and a substituent at the 4'-position can be preferably used because of their availability.

Specific examples thereof include [1,1'-biphenyl] -4-carboxylic acid, 4'-methyl [1,1 '.
-Biphenyl] -4-carboxylic acid, 4'-ethyl [1,
1'-biphenyl] -4-carboxylic acid, 4'-propyl [1,1'-biphenyl] -4-carboxylic acid, 4'-isopropyl [1,1'-biphenyl] -4-carboxylic acid, 4'- Butyl [1,1′-biphenyl] -4-carboxylic acid, 4′-sec-butyl [1,1′-biphenyl] -4-carboxylic acid, 4′-isobutyl [1,1′-
Biphenyl] -4-carboxylic acid, 4'-tert-butyl [1,1'-biphenyl] -4-carboxylic acid, 4'-
Pentyl [1,1′-biphenyl] -4-carboxylic acid,
4'-hexyl [1,1'-biphenyl] -4-carboxylic acid, 4'-heptyl [1,1'-biphenyl] -4-
Carboxylic acid, 4'-octyl [1,1'-biphenyl]
-4-carboxylic acid, 4'-nonyl [1,1'-biphenyl] -4-carboxylic acid, 4'-decyl [1,1'-biphenyl] -4-carboxylic acid, 4'-undecyl [1,
1′-biphenyl] -4-carboxylic acid, 4′-dodecyl [1,1′-biphenyl] -4-carboxylic acid, 4′-tridecyl [1,1′-biphenyl] -4-carboxylic acid,
4'-tetradecyl [1,1'-biphenyl] -4-carboxylic acid, 4'-chloro [1,1'-biphenyl] -4
-Carboxylic acid, 4'-bromo [1,1'-biphenyl]
-4-carboxylic acid, 4'-nitro [1,1'-biphenyl] -4-carboxylic acid, 4'-dimethylamino [1,
1'-biphenyl] -4-carboxylic acid, 4'-hydroxy [1,1'-biphenyl] -4-carboxylic acid, 4'-
Methoxy [1,1'-biphenyl] -4-carboxylic acid,
4'-ethoxy [1,1'-biphenyl] -4-carboxylic acid, 4'-propoxy [1,1'-biphenyl] -4
-Carboxylic acid, 4'-isopropoxy [1,1'-biphenyl] -4-carboxylic acid, 4'-butoxy [1,1 '
-Biphenyl] -4-carboxylic acid, 4'-sec-butoxy [1,1'-biphenyl] -4-carboxylic acid, 4 '
-Isobutoxy [1,1'-biphenyl] -4-carboxylic acid, 4'-tert-butoxy [1,1'-biphenyl] -4-carboxylic acid, 4'-pentyloxy [1,
1'-biphenyl] -4-carboxylic acid, 4'-hexyloxy [1,1'-biphenyl] -4-carboxylic acid,
4'-heptyloxy [1,1'-biphenyl] -4-
Carboxylic acid, 4'-octyloxy [1,1'-biphenyl] -4-carboxylic acid, 4'-nonyloxy [1,
1'-biphenyl] -4-carboxylic acid, 4'-decyloxy [1,1'-biphenyl] -4-carboxylic acid, 4 '
-Undecyloxy [1,1'-biphenyl] -4-carboxylic acid, 4'-dodecyloxy [1,1'-biphenyl] -4-carboxylic acid, 4'-tridecyloxy [1,
1'-biphenyl] -4-carboxylic acid and 4'-tetradecyloxy [1,1'-biphenyl] -4-carboxylic acid can be exemplified.

Next, a difunctional carboxylic acid compound is preferably used as the polyfunctional carboxylic acid. Examples of the bifunctional carboxylic acid include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid. , Phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 2,5
-Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, [1,1 '
-Biphenyl] -4,4'-dicarboxylic acid, fumaric acid, maleic acid, stilbene-4,4'-dicarboxylic acid, [1,1'-dicyclohexane] -4,4'-dicarboxylic acid, 4,4 ' -Isopropylidene bis (phenoxyacetic acid), benzene-1,4-diylbis (3-propenyl acid) and the like having 6 to 30 carbon atoms, preferably 6 to 2 carbon atoms.
The dicarboxylic acid derivative of 0 can be mentioned.

Further, a benzoic acid group, a naphthoic acid group, [1,
A dicarboxylic acid having a C2 to C20 organic group sandwiched between two groups selected from 1′-biphenyl] carboxylic acid groups can also be preferably used, and examples thereof are shown below. Although the substitution position is not shown here, for example, in the case of using a benzoic acid derivative, it is possible to generally use a compound in which any of the 2, 3 and 4 positions is substituted, but a 4-substituted product is preferred because of ease of production and the like. Most preferably used. When a naphthoic acid derivative is used, generally, any isomer of substituted naphthoic acid can be preferably used, but preferably, the carboxyl group is at the 2-position of naphthalene, and the substituent is at the 6-position or The one at the 7th position, preferably the 6th position is used. Furthermore, [1,1'-
As the biphenyl] carboxylic acid derivative, any isomer can be preferably used, but preferably, the carboxyl group is used at the 4-position of the [1,1′-biphenyl] group, and the substituent is at the 4′-position. The one in the position of is used.

Specific examples thereof include 4,4 '-(ethane-1,2-diylbisoxy) bisbenzoic acid and 4,4'-(ethane-1,2-diylbisoxy) bisbenzoic acid.
4 '-(propane-1,3-diylbisoxy) bisbenzoic acid, 4,4'-(butane-1,4-diylbisoxy) bisbenzoic acid, 4,4 '-(pentane-1,5- Diylbisoxy) bisbenzoic acid, 4,4 ′-(hexane-1,6-diylbisoxy) bisbenzoic acid, 4,4 ′
-(Heptane-1,7-diylbisoxy) bisbenzoic acid, 4,4 '-(octane-1,8-diylbisoxy) bisbenzoic acid, 4,4'-(nonane-1,9-diylbis Oxy) bisbenzoic acid, 4,4 ′-(decane-
1,10-diylbisoxy) bisbenzoic acid, 4,4 ′
-(Undecane-1,11-diylbisoxy) bisbenzoic acid, 4,4 '-(dodecane-1,12-diylbisoxy) bisbenzoic acid, 4,4'-(benzene-1,4)
-Diylbisoxy) bisbenzoic acid, 4,4 '-(benzene-1,4-dimethyl-α, α'-diylbisoxy) bisbenzoic acid, 4,4'-(cyclohexane-1,
4-Dimethyl-α, α′-diylbisoxy) bisbenzoic acid, 6,6 ′-(ethane-1,2-diylbisoxy) bis (2-naphthoic acid), 6,6 ′-(propane-
1,3-diylbisoxy) bis (2-naphthoic acid),
6,6 '-(butane-1,4-diylbisoxy) bis (2-naphthoic acid), 6,6'-(pentane-1,5-
Diylbisoxy) bis (2-naphthoic acid), 6,6 '
-(Hexane-1,6-diylbisoxy) bis (2-
Naphthoic acid), 6,6 ′-(heptane-1,7-diylbisoxy) bis (2-naphthoic acid), 6,6 ′-(octane-1,8-diylbisoxy) bis (2-naphthoic acid) ), 6,6 ′-(nonane-1,9-diylbisoxy) bis (2-naphthoic acid), 6,6 ′-(decane-)
1,10-diylbisoxy) bis (2-naphthoic acid), 6,6 '-(undecane-1,11-diylbisoxy) bis (2-naphthoic acid), 6,6'-(dodecane-1, 12-diylbisoxy) bis (2-naphthoic acid), 6,6 '-(benzene-1,4-diylbisoxy) bis (2-naphthoic acid), 6,6'-(benzene-
1,4-dimethyl-α, α′-diylbisoxy) bis (2-naphthoic acid), 6,6 ′-(cyclohexane-
1,4-dimethyl-α, α′-diylbisoxy) bis (2-naphthoic acid), 4 ′, 4 ″ ′-(ethane-1,2)
-Diylbisoxy) bis ([1,1'-biphenyl]
-4-carboxylic acid), 4 ', 4'''-(propane-1,
3-diylbisoxy) bis ([1,1′-biphenyl] -4-carboxylic acid), 4 ′, 4 ′ ″-(butane-
1,4-diylbisoxy) bis ([1,1′-biphenyl] -4-carboxylic acid), 4 ′, 4 ′ ″-(pentane-1,5-diylbisoxy) bis ([1,1 '-Biphenyl] -4-carboxylic acid), 4', 4 '''-(hexane-1,6-diylbisoxy) bis ([1,1'-biphenyl] -4-carboxylic acid), 4', 4 '''-(heptane-1,7-diylbisoxy) bis ([1,1'-
Biphenyl] -4-carboxylic acid), 4 ′, 4 ′ ″-(octane-1,8-diylbisoxy) bis ([1,1 ′
-Biphenyl] -4-carboxylic acid), 4 ', 4'''-
(Nonane-1,9-diylbisoxy) bis ([1,
1'-biphenyl] -4-carboxylic acid), 4 ', 4'''
-(Decane-1,10-diylbisoxy) bis ([1,1'-biphenyl] -4-carboxylic acid),
4 ', 4'"-(Undecane-1,11-diylbisoxy) bis ([1,1'-biphenyl] -4-carboxylic acid), 4 ', 4"'-(dodecane-1,12 -Diylbisoxy) bis ([1,1'-biphenyl] -4-carboxylic acid), 4 ', 4'"-(benzene-1,4-diylbisoxy) bis ([1,1'-biphenyl ] -4-Carboxylic acid), 4 ′, 4 ′ ″-(benzene-1,4-dimethyl-α.α′-diylbisoxy) bis ([1,1 ′
-Biphenyl] -4-carboxylic acid), 4 ', 4'''-
(Cyclohexane-1,4-dimethyl-α, α′-diylbisoxy) bis ([1,1′-biphenyl] -4-
Carboxylic acid) and the like.

Further, two terminal hydroxy groups such as diethylene glycol, triethylene glycol and tetraethylene glycol are combined with a hydroxy group such as hydroxybenzoic acid, hydroxynaphthoic acid and hydroxy [1,1'-biphenyl] carboxylic acid to form an ether bond. Compounds obtained by forming can also be used. Furthermore, in these bifunctional carboxylic acids containing benzoic acid, naphthoic acid and [1,1′-biphenyl] carboxylic acid group, different compounds such as benzoic acid group on one side and naphthoic acid group on the other side are used. Can also be used.

Further, a compound having three or more carboxylic acid groups in one molecule can also be used. Examples of these are benzene-1,3,5-tricarboxylic acid, 4,
4 ′, 4 ″-(propane-1,2,3-triyltrisoxy) tris (benzoic acid) and the like can be mentioned.

In the present invention, a plurality of kinds of carboxylic acid compounds as described above are used to obtain a discotic liquid crystal material bonded to any of the discogen substitution sites. As a combination of plural kinds of carboxylic acid compounds, as a combination of monofunctional carboxylic acid compounds, (1) benzoic acid derivative + naphthoic acid derivative (2) benzoic acid derivative + [1,1′-biphenyl]
Carboxylic acid derivative (3) Benzoic acid derivative + Cinnamic acid derivative (4) Naphthoic acid derivative + Cinnamic acid derivative (5) Naphthoic acid derivative + [1,1'-biphenyl] carboxylic acid derivative (6) Cinnamic acid derivative + [1 , 1'-Biphenyl] carboxylic acid derivative (7) Benzoic acid derivative + Naphthoic acid derivative + Cinnamic acid derivative (8) Benzoic acid derivative + [1,1'-biphenyl]
Carboxylic acid derivative + Cinnamic acid derivative (9) Benzoic acid derivative + Naphthoic acid derivative +
[1,1'-Biphenyl] carboxylic acid derivative (10) Benzoic acid derivative + alkanoic acid (11) Benzoic acid derivative + Alkenic acid (12) Alkanoic acid + Naphthoic acid derivative (13) Alkenic acid + Naphthoic acid derivative (14) Examples include plural kinds of benzoic acid derivatives (15) plural kinds of naphthoic acid derivatives (16) plural kinds of [1,1′-biphenyl] carboxylic acid derivatives (17) plural kinds of cinnamic acid derivatives.

Further, the combination of the monofunctional carboxylic acid compound and the polyfunctional carboxylic acid compound includes (1) a dicarboxylic acid derivative having 6 to 30 carbon atoms + a benzoic acid derivative (2) a dicarboxylic acid having 6 to 30 carbon atoms Derivative + naphthoic acid derivative (3) C6 to C30 dicarboxylic acid derivative + benzoic acid derivative + naphthoic acid derivative (4) C6 to C30 dicarboxylic acid derivative + cinnamic acid derivative (5) C6 to C30 Dicarboxylic acid derivative + cinnamic acid derivative + benzoic acid derivative (6) C6 to C30 dicarboxylic acid derivative + cinnamic acid derivative + benzoic acid derivative + naphthoic acid derivative (7) C6 to C30 dicarboxylic acid derivative +
[1,1′-Biphenyl] carboxylic acid derivative (8) Dicarboxylic acid derivative having 6 to 30 carbon atoms +
[1,1'-Biphenyl] carboxylic acid derivative + benzoic acid derivative (9) Dicarboxylic acid derivative having 6 to 30 carbon atoms +
[1,1'-Biphenyl] carboxylic acid derivative + naphthoic acid derivative (10) Dicarboxylic acid derivative having 6 to 30 carbon atoms +
[1,1'-Biphenyl] carboxylic acid derivative + benzoic acid derivative + naphthoic acid derivative (11) Dicarboxylic acid derivative having 6 to 30 carbon atoms +
[1,1'-Biphenyl] carboxylic acid derivative + cinnamic acid derivative (12) Dicarboxylic acid derivative + benzoic acid derivative + naphthoic acid derivative in which C2-C20 organic groups are sandwiched by two benzoic acid groups (13) ) A dicarboxylic acid derivative in which a C2-C20 organic group is sandwiched by two benzoic acid groups + a benzoic acid derivative + [1,1'-biphenyl] carboxylic acid derivative (14) C2 is formed by two benzoic acid groups. To C20 organic group sandwiched between dicarboxylic acid derivatives + benzoic acid derivatives + naphthoic acid derivatives + [1,1'-biphenyl] carboxylic acid derivatives (15) Two benzoic acid groups form C2 to C20 organic groups Dicarboxylic acid derivative sandwiched between + benzoic acid derivative + naphthoic acid derivative + [1,1'-biphenyl] carboxylic acid derivative (16) C2-C2 depending on two benzoic acid groups Dicarboxylic acid derivative in which organic groups are sandwiched + Benzoic acid derivative + Naphthoic acid derivative + [1,1'-biphenyl] carboxylic acid derivative + Alkanoic acid (17) C2-C20 organic group by two naphthoic acid groups Dicarboxylic derivative in which group is sandwiched + Benzoic acid derivative + Naphthoic acid derivative (18) Dicarboxylic derivative in which C2 to C20 organic group is sandwiched by two naphthoic acid groups + Benzoic acid derivative + [1,1 '-Biphenyl] carboxylic acid derivative (19) Dicarboxylic derivative in which C2-C20 organic group is sandwiched by two naphthoic acid groups + benzoic acid derivative + naphthoic acid derivative + [1,1'-biphenyl] carboxylic acid Derivative (20) Dicarboxylic acid derivative in which C2 to C20 organic group is sandwiched by two [1,1'-biphenyl] carboxylic acid groups + benzoic acid derivative (21) Dicarboxylic acid derivative in which C2-C20 organic group is sandwiched by two [1,1'-biphenyl] carboxylic acid groups + naphthoic acid derivative (22) [1,1'-biphenyl] carboxylic acid A dicarboxylic acid derivative in which a C2-C20 organic group is sandwiched by two groups + a benzoic acid derivative + a naphthoic acid derivative (23) [2, 1,1'-biphenyl] carboxylic acid Dicarboxylic acid derivative in which organic group is sandwiched + cinnamic acid derivative + naphthoic acid derivative (24) [1,1′-biphenyl] dicarboxylic acid derivative in which C2 to C20 organic group is sandwiched by two carboxylic acid groups Examples thereof include acid derivatives + cinnamic acid derivatives + benzoic acid derivatives.

According to the production method of the present invention, the characteristics such as the phase transition temperature of the discotic liquid crystal material and the orientation form of molecules in the liquid crystal state of the liquid crystal material are determined by the planar condensed ring compound and / or carboxylic acid to be combined. It can be adjusted by selecting various compounds. In addition, it is possible to obtain a reaction product having a desired phase transition temperature, that is, a discotic liquid crystal material, also by the reaction conditions described later.

Next, the reaction conditions of the present invention will be described.
In the production method of the present invention, a planar condensed ring compound having 6 or more phenolic hydroxyl groups in one molecule, an acetylating agent and a carboxylic acid compound are supplied to the reaction system. In the reaction system, by charging the hydroxy form, the acetylating agent and the carboxylic acid compound into a reactor, the acetylation reaction of the hydroxy form and the deacetic acid reaction between the acetyl group and the carboxyl group of the carboxylic acid compound can be carried out in one step.
Proceed in one reaction vessel.

As the acetylating agent used in this acetylation reaction, for example, acetyl ketene, ketene, N
-Acetylimidazole, acetic anhydride and the like can be mentioned, but acetic anhydride is particularly preferable. The acetylating agent is used in an amount of usually 1.5 to 20 times, preferably 2 to 10 times the molar amount of the phenolic hydroxyl group contained in the planar condensed ring compound. The reaction temperature of the acetylation reaction is usually 50 ° C to 200 ° C, preferably 80 ° C to
It is 180 ° C. The reaction time is usually 10 minutes to 2 hours.

Next, the reaction between the acetylated compound of the planar condensed ring compound obtained under the above conditions and the carboxylic acid compound will be described. In the dereaction, theoretically, the charging molar ratio is set so that the ratio of the number of moles of acetyl groups contained in the acetylated compound to the number of moles of carboxyl groups contained in the carboxylic acid compound is 1. However, in actual operation, it is not always necessary to accurately set the molar ratio to 1, and usually 0.80 to 1.20, preferably 0.95 to 1.0.
The ratio is set to 5. For example, if the raw material of the substituent, that is, the carboxylic acid compound may be scattered out of the reaction system during the reaction due to sublimation or the like, the carboxylic acid may be increased a little. When too much carboxylic acid compound is used, a large amount of unreacted carboxylic acid compound remains in the reaction product, which may adversely affect liquid crystallinity. On the other hand, needless to say, when it is not necessary to completely substitute the carboxylic acid compound at the substitution site of the planar condensed ring compound, a small amount of the substituent group can be used. From the above, the production method of the present invention does not require a carboxylic acid compound serving as an excessive substituent with respect to the planar condensed ring compound, and therefore a purification step such as removal of unreacted carboxylic acid compound is not always required. do not need.

The reaction temperature in the above reaction is usually 200.
C. to 300.degree. C., preferably 220.degree. C. to 280.degree. If the reaction temperature is too low, the reaction rate becomes extremely slow, which is not preferable. On the other hand, if the temperature is too high, the decomposition proceeds, which may deteriorate the liquid crystallinity or the hue, which is not desirable. In the present invention, it is generally desirable to charge the raw materials of the planar condensed ring compound having 6 or more phenolic hydroxyl groups in one molecule, the carboxylic acid compound and the acetylating agent as described above at room temperature. .

In obtaining a reaction product, ie, a discotic liquid crystal material, which is used in the method for producing a compensating plate for a liquid crystal display device of the present invention, it is usually unnecessary to adjust the pressure during the reaction, but distilling of raw materials or If necessary, for example, when sublimation is remarkable, it can be carried out under a pressure atmosphere of 1 atm or more. On the other hand, when it is necessary to accelerate the distillation of acetic acid and the like produced as a by-product during the reaction, it can be carried out under reduced pressure. Furthermore, it is possible to carry out the reaction while flowing an inert gas such as nitrogen in order to accelerate the distillation of the acetic acid and the like. Generally, in the initial stage of the condensation reaction, there are many components having a low molecular weight and easily distilled or sublimated. Therefore, during this time period, operations under reduced pressure or under an inert gas stream should be avoided. On the other hand, the latter half of the reaction, specifically, the latter half of the whole reaction time 1/3 to 9/10, preferably 1
/ 2 to 4/5, the reaction is performed under reduced pressure or under an inert gas stream for the purpose of promoting the distillation of acetic acid by-produced and obtaining a discotic liquid crystal material having a desired liquid crystal transition point. It is preferable to carry out. By performing this operation, the liquid crystal transition rate can be increased. The total reaction time, which will be specifically described later, means the period from the time when the planar condensed ring compound, the carboxylic acid compound and the acetylating agent are provided in the reactor to the end of the reaction. At this time, the inert gas is not particularly limited as long as it does not adversely affect the obtained liquid crystal material, and specific examples thereof include helium, argon, methane, nitrogen and carbon dioxide. Nitrogen is preferably used. The flow rate of the inert gas is not particularly limited as long as it does not hinder the deacetic acid reaction, but is usually 10 to 1000, preferably 30 to 1000 as a value of [flow rate (ml / min) ÷ reactor capacity (liter)]. It is 300. In the present invention, this operation can adjust the phase transition temperature of the discotic liquid crystal material.

The total reaction time is usually 1 hour to 48 hours, preferably 3 hours to 24 hours. If the reaction time is short, sufficient liquid crystallinity may not be obtained. On the other hand, if the reaction time is too long, the decomposition of the product proceeds, which may adversely affect the hue and the like, which is not desirable.

In the production method of the present invention, the material of the reactor used is not particularly limited, but it is necessary that it is not corroded by acetic acid produced as a by-product, and is generally a glass reactor or a stainless reactor. A Hastelloy reactor, a reactor lined with glass, titanium, gold, silver, Teflon, or the like is preferably used. According to the manufacturing method of the present invention, a discotic liquid crystal material suitable for an optical material can be easily obtained without using a solvent.

In order to obtain a reaction product, ie, a discotic liquid crystal material, which is used in the method for producing a compensating plate for a liquid crystal display device of the present invention, a specific substituent is introduced into a specific position of one discogen. There is no need to perform such advanced selectivity control. In the production method of the present invention, a planar fused ring compound that provides a discogen moiety and a plurality of carboxylic acid compounds that provide side chain moieties are simultaneously allowed to proceed in a single reaction vessel to prepare a discotic material suitable for optical element materials. A liquid crystal material can be obtained. In this case, it is of course possible to use the compound which gives a plurality of discogen moieties, and there is no problem even if the compound is mixed with a plurality of carboxylic acid compounds which give a substituent moiety for use in the reaction. Of course, in this case, the discotic liquid crystal material obtained in this case is a composition of discotic liquid crystal compounds having various substituent distributions as a reaction product, but when used as an optical material, a transition from a liquid crystal phase to a crystalline phase occurs. Is not desirable. In that respect, it is a very preferable embodiment to use various kinds of substituents as described above, for example, to reduce the symmetry of the molecule. Furthermore, there is no problem in mixing a plurality of reaction products having different reaction conditions or charged raw materials and using them as discotic liquid crystal materials.

The method for producing the discotic liquid crystal material has been described above in detail. When the discotic liquid crystal material obtained by the production method of the present invention is used as an optical material, it need not be further purified, but it is necessary. If so, it can be purified by a method such as reprecipitation or chromatography.

Next, a method of manufacturing the compensating plate for a liquid crystal display device of the present invention will be described. The compensating plate for a liquid crystal display device of the present invention is manufactured by applying the discotic liquid crystal material obtained as described above on an alignment substrate, followed by heat treatment and cooling. As the alignment substrate, the alignment ability, required heat resistance, solvent resistance, and the type and properties of the discotic liquid crystal to be used are different, so it cannot be generally stated.
Typical examples of the oriented substrate used include aluminum,
A metal plate such as iron or steel, a plate made of ceramics, an enamel plate, a sheet-shaped or plate-shaped substrate such as glass, and obtained by a known formulation, for example, a rubbed polyimide film, polyvinyl alcohol film, or silicon oxide. Examples thereof include those having an alignment film having an alignment ability such as the obliquely vapor-deposited film. Further, as other examples, polyimide, polyamide imide, polyether imide, polyamide, polyether ether ketone, polyether ketone, polyketone sulfide, polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, Polyacetal, polycarbonate, acrylic resin, polyvinyl alcohol, cellulosic plastics, epoxy resin, phenol resin and other plastics film or sheet surface, rubbing-treated polyimide film, polyvinyl alcohol film, or silicon dioxide oblique vapor deposition film orientation An example of the substrate is a substrate having an orientation film having a function. In addition, an oriented substrate in which the surface of these plastic films is directly rubbed may be used. Of these plastics films or sheets, those with high crystallinity may have the ability to orientate discotic liquid crystals only by uniaxially stretching them, and for those, direct rubbing treatment or orientation film such as rubbing polyimide film. Can be used as it is as an alignment substrate. Specific examples include polyimide, polyetherimide, polyetheretherketone, polyetherketone, polyphenylene sulfide, polyethylene terephthalate, and the like.

By coating, heat-treating and cooling a discotic liquid crystal material on these alignment substrates, a fixed thin film (compensation plate) is formed on the alignment substrates without impairing the alignment form in the liquid crystal state.

To apply the discotic liquid crystal material onto the alignment substrate, the material is melted and applied by melt coating,
And solution coating in which the material is dissolved and applied in a solvent. In the present invention, solution coating is desirable in the manufacturing process.

The solvent used for applying the solution depends on the type of discotic liquid crystal material, but is usually a halogenated substance such as chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene. Hydrocarbons, phenols, phenols such as parachlorophenol, benzene, toluene, xylene, ethylbenzene, methoxybenzene, 1,2-
Aromatic hydrocarbons such as dimethoxybenzene, acetone, methyl ethyl ketone, ethyl acetate, tert-butyl alcohol, glycerin, ethylene glycol, triethylene glycol, hexylene glycol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, ethyl cellosolve, butyl cellosolve , Γ-butyrolactone, 2-pyrrolidone, N-methyl-2-pyrrolidone, pyridine, triethylamine, dimethylformamide, dimethylacetamide, acetonitrile, butyronitrile, dimethyl sulfoxide, carbon disulfide, etc., and mixed solvents thereof are used. .

The concentration of the solution depends on the solubility of the discotic liquid crystal material and the film thickness of the compensator and cannot be generally stated, but it is usually used in the range of 1 to 60% by weight, preferably 3 to 40% by weight. Used in the range of%.

As a coating method, for example, a spin coating method, a roll coating method, a printing method, a dipping and pulling method, a curtain coating method (die coating method) or the like is used to coat the alignment substrate with a solution in which a discotic liquid crystal material is dissolved. Form a film. In the manufacturing method of the present invention, the coating film can be formed by using one or two alignment substrates. In the present invention, it is usually preferable to form the coating film by utilizing one orientation substrate and the air interface in terms of cost and simplification of the production line.

After coating, the solvent is removed and a layer of discotic liquid crystal material having a uniform thickness is formed on the alignment substrate. The conditions for removing the solvent are not particularly limited, as long as the solvent can be almost removed and the layer of the liquid crystal material does not flow or flow down. Usually, the solvent is removed by air drying at room temperature, drying on a hot plate, drying in a drying furnace, or blowing hot or hot air.

After removing the solvent, a uniform and mono-domain thin film is preferably formed on the alignment substrate by heat treatment. The heat treatment is performed by aligning in the liquid crystal state of the discotic liquid crystal material, or by bringing the liquid crystal phase into an isotropic fluid state at a temperature higher than the temperature range in which the liquid crystal phase is exhibited, and then lowering the temperature to the temperature range in which the liquid crystal phase is exhibited. To do. The heat treatment temperature is usually in the range of 50 to 300 ° C., especially 10
The range of 0-270 degreeC is suitable. Further 150-25
A temperature of 0 ° C. is preferred. The time required to obtain sufficient alignment in the liquid crystal state on the alignment film varies depending on the type and molecular weight of the discotic liquid crystal material and cannot be generally stated, but is usually in the range of 5 seconds to 2 hours, and preferably 10 seconds.
It is carried out in the range of seconds to 40 minutes, particularly preferably in the range of 20 seconds to 20 minutes. If the time is shorter than 5 seconds, the temperature of the discotic liquid crystal material layer may not reach the predetermined temperature and the orientation may be insufficient. Further, if it is longer than 2 hours, the productivity is lowered, which is not preferable.

A similar alignment form can be obtained by applying a heat treatment after applying the discotic liquid crystal material in a molten state on the alignment substrate. It is also possible to align the discotic liquid crystal material layer while applying an electric field or magnetic field while performing heat treatment.

By cooling the alignment form thus obtained to a temperature below the glass transition point of the liquid crystal material, the alignment form in the liquid crystal state can be fixed without impairing the alignment form. In general, when a crystal phase appears in the cooling process, the orientation in the liquid crystal state is destroyed along with crystallization, but the discotic liquid crystal material used in the present invention has no crystal phase or has a latent phase. Even if it has a crystalline phase, it has the property that the crystalline phase does not appear on cooling, or no clear crystal transition point or liquid crystal transition point is confirmed, but it has no fluidity within the temperature range used as a compensating element. In addition, since the orientation morphology does not change even when an external field or external force is applied, the orientation morphology is not destroyed by crystallization.

The cooling condition can be fixed uniformly by only taking out from the heat treatment atmosphere to room temperature. In addition, forced cooling such as air cooling or water cooling or slow cooling may be performed without any limitation, and the cooling rate is not particularly limited.

The orientation of the compensator of the present invention obtained by cooling after the heat treatment varies depending on the orientation conditions, the type and properties of the discotic liquid crystal material, and the like. As for the alignment form, the director of the discotic liquid crystal has a homeotropic alignment in the normal direction of the alignment substrate (a in FIG. 1), and the director has a negative alignment such as a tilt alignment inclined at a certain angle from the normal direction of the alignment substrate. Uniaxial structure (b in FIG. 1), or a hybrid orientation in which the director has different angles in the vicinity of one interface of the discotic liquid crystal layer and in the vicinity of the other opposite interface (c of FIG. 1). ) And the like.

The compensator made of the discotic liquid crystal material according to the present invention may have any of the above-mentioned alignment forms, preferably shows a uniform and monodomain discotic nematic phase, and is formed in the liquid crystal state. A compensator having a morphology easily fixed without impairing the alignment morphology, and more preferably a film having a uniform and monodomain discotic nematic phase and having a liquid crystal state at the upper and lower interfaces of the compensator. The director of the discotic liquid crystal in the thickness direction is a compensating plate in which the angle formed by the compensator normal and the director is different between near the upper interface and near the lower interface of the compensator. Here, the hybrid orientation means that in a single-layer thin film, the directors of the discotic liquid crystal present at both interfaces of the thin film, that is, near the thin film interface on the alignment substrate side and the opposite thin film interface are It means an orientation mode in which the projection vectors are in the same direction but the angles in the film thickness direction are different. The angle range in the film thickness direction is the absolute value of the minimum angle formed by the director of the discotic liquid crystal molecule existing near the interface of the compensator and the normal to the compensator plane, that is, the director of the liquid crystal molecule and the compensator plane. The angle obtained by [90 degrees-a degrees] is the upper surface of the compensator when the angle that is not on the obtuse angle side (the angle within the range of 0 degrees to 90 degrees) formed by the normal line in Alternatively, one of the lower surfaces usually forms an angle of 60 degrees or more and 90 degrees or less, and the opposite surface of the surface is usually 0 degrees or more and 50 degrees or less. More preferably, the absolute value of one angle is 80 degrees or more and 90 degrees or less, and the absolute value of the other angle is 0 degrees or more and 30 degrees or less.

In the compensating plate for a liquid crystal display element of the present invention, since the directors are preferably oriented in different directions in the thickness direction because they form a hybrid alignment, when viewed as a structure called a compensating plate, it is no longer a light source. There is no axis and uniaxiality is lost. When light passes through such an alignment form of the liquid crystal, it is possible to observe a complicated birefringence behavior that has not been obtained conventionally.

In the above hybrid orientation, the absolute value of the angle between the compensator normal and the director of the discotic liquid crystal molecules existing near the compensator interface and the compensator plane is either on the upper surface or the lower surface of the compensator. Is within a range of 0 ° or more and 90 ° or less, and on the surface opposite to the surface within a range of 0 ° or more and 50 ° or less, a discotic liquid crystal material to be used, an alignment substrate, or the like is appropriately selected. It can be adjusted to each angle. Also, even after forming the compensator once, for example,
The angle can be adjusted to a desired angle by using a method such as uniformly scraping the surface of the compensator or immersing it in a solvent to uniformly dissolve the surface of the compensator. The solvent used at this time is appropriately selected depending on the type of discotic liquid crystal material and alignment substrate.

The discotic liquid crystal material used in the present invention does not cause a transition from a liquid crystal phase to a crystalline phase when it is fixed from a liquid crystal state. Therefore, the liquid crystal material can be fixed without impairing the alignment form formed in the liquid crystal state. After forming the compensator,
It is desirable that the oriented form be maintained under the conditions of use and that it can be handled like a solid. The fixed state here is a state in which the liquid crystal structure is frozen in an amorphous glass state, which is the most typical and preferable mode.
It is not limited to that. That is, a compensator formed of a discotic liquid crystal material is used under the conditions of use of the compensator for a liquid crystal display device, specifically in the temperature range of usually 0 ° C to 50 ° C and -30 ° C to 70 ° C under more severe conditions. It means a state in which the alignment form formed in the liquid crystal state can be kept stable without showing any fluidity and without causing a change in the alignment form due to an external force or an external field.

As described above, a compensator for a liquid crystal display device can be manufactured by applying a discotic liquid crystal material on an alignment substrate, heat-treating it, and then cooling it. When the compensating plate obtained by the manufacturing method of the present invention is actually arranged in a liquid crystal cell, the above-mentioned alignment substrate is peeled from the compensating plate, and the compensating plate is used as it is, as it is formed on the alignment substrate. It is conceivable that it will be used in.

When the compensating plate is used alone, the alignment substrate is mechanically peeled off at the interface with the compensating plate using a roll or the like, or it is immersed in a poor solvent for all structural materials and then mechanically peeled off. , A method of peeling by applying ultrasonic waves in a poor solvent, a method of peeling by giving a temperature change by utilizing a difference in thermal expansion coefficient between the alignment substrate and the compensator, the alignment substrate itself, or an alignment film on the alignment substrate A method of dissolving and removing the can be exemplified. The releasability depends on the adhesiveness between the discotic liquid crystal material used and the alignment substrate, and therefore the method most suitable for the system should be adopted.

Next, when the compensating plate is used on the alignment substrate, if the alignment substrate is transparent and optically isotropic, or if the alignment substrate is a member necessary for a liquid crystal display element. It can be used as it is as an intended optical compensation element. Further, the compensating plate obtained by aligning and fixing the discotic liquid crystal material on the alignment substrate can be peeled off from the substrate and transferred to another substrate more suitable for optical use.

For example, although the alignment substrate used is necessary to obtain a hybrid alignment form, for example,
When the substrate is used, which has an unfavorable effect on the properties when used as a compensating element, the substrate can be removed from the compensating plate before use. Specifically, the following method can be adopted.

A substrate suitable for the target compensating element (hereinafter,
The second substrate) and the compensator on the alignment substrate are attached using an adhesive or a pressure-sensitive adhesive. Next, the alignment substrate is peeled off at the interface between the alignment substrate and the compensating plate, and the compensating plate, that is, the discotic liquid crystal material layer is transferred to the second substrate side suitable for the compensating device to manufacture the target compensating device. Is possible.

The second substrate used for transfer is not particularly limited as long as it has appropriate flatness,
Glass or a transparent plastic film having optical isotropy is preferable. Examples of such plastic film include polymethacrylate, polystyrene, polycarbonate, polyether sulfone, polyphenylene sulfide, polyarylate, amorphous polyolefin, triacetyl cellulose, epoxy resin and the like. Among them, polymethyl methacrylate, polycarbonate, polyarylate, triacetyl cellulose, polyether sulfone and the like are preferably used. Further, even if it is optically anisotropic, it can be used when it is a member necessary for a liquid crystal display element. Examples of such materials include retardation films and polarizing films obtained by stretching a plastic film such as polycarbonate and polystyrene.

As an example of the second substrate used further,
The liquid crystal display cell itself can be mentioned. The liquid crystal display cell uses a glass or plastic substrate with two upper and lower electrodes, and if the compensating plate of the present invention is transferred to either the upper or lower side or both sides, the incorporation of the compensating plate has already been achieved. become. It is of course possible to manufacture the compensator of the present invention by using the glass substrate or the plastic substrate forming the display cell itself as the alignment substrate.

The adhesive or pressure-sensitive adhesive for adhering the second substrate and the orientation-fixed discotic liquid crystal material layer used for transfer is not particularly limited as long as it is an optical grade, but acrylic or epoxy. A system, an ethylene-vinyl acetate copolymer system, a rubber system, etc. can be used.

The method of transferring the compensating plate of the present invention to the second substrate suitable for the compensating element can be carried out by peeling the oriented substrate after adhesion at the interface with the compensating plate. The peeling method was described above, but it is mechanically peeling using a roll, etc., mechanically peeling after dipping in a poor solvent for all structural materials, and peeling by applying ultrasonic waves in a poor solvent. Method, peeling by giving a temperature change utilizing the difference in thermal expansion coefficient between the alignment substrate and the compensation plate, the alignment substrate itself,
Alternatively, a method of dissolving and removing the alignment film on the alignment substrate can be exemplified. The releasability depends on the adhesiveness between the discotic liquid crystal material used and the alignment substrate, and therefore the method most suitable for the system should be adopted.

The compensator of the present invention further comprises an acrylic or epoxy-based overcoat layer on one or both sides of the discotic liquid crystal for the purpose of protecting the optically important discotic liquid crystal material layer, that is, the compensator surface. Can be provided. These are not essential for the compensator of the present invention, but are preferably optically isotropic, and these can increase the strength as an optical element and increase the durability as a product. You can

The compensation plate of the present invention thus obtained has a color / viewing angle compensation effect for a liquid crystal display as described above. Above all, a viewing angle compensating effect (a viewing angle improving effect) is exerted on a display in which a TN liquid crystal cell is driven in a normally white mode, and a color / viewing angle compensating effect is exerted on an OCB mode liquid crystal display. The film thickness of the compensating plate for the compensating plate of the present invention to exhibit a compensating effect for various liquid crystal displays depends on the system and parameters of the target liquid crystal display and cannot be generally stated, but is usually 0.1 μm. The above range is 40 μm or less, more preferably 0.2 μm or more and 20 μm or less, and particularly preferably 0.4 μm or more and 10 μm or less. If the film thickness is less than 0.1 μm, the compensation effect may not be sufficiently obtained. If the film thickness exceeds 40 μm, the display may unnecessarily be colored.
However, in order to maximize the performance of the compensator of the present invention, it is preferable to consider the compensator parameters and axial arrangement in more detail.

In general, the optical parameters and the physical property values that characterize the structure of the compensator include the angle of the director, the film thickness, the apparent in-plane retardation, and the average tilt angle, which will be described below. .

First, the angle formed by the director of the discotic liquid crystal near the interface of the compensating plate with the plane of the compensating plate is 60 degrees or more and 90 degrees or less, preferably 70 degrees or more, either near the upper surface or the lower surface of the compensating plate. It is preferable that an angle of 90 degrees or less is formed, and 0 degrees or more and 50 degrees or less, and preferably 0 degrees or more and 30 degrees or less on the opposite surface. If this condition is not satisfied, the director of the liquid crystal is almost parallel to the substrate interface near the substrate interface, which is a feature of the refractive index structure at the time of selective display of the liquid crystal cell, and the vertical direction at the central portion in the film thickness direction causes a change in the refractive index. On the other hand, there is a risk that compensation will not be fully achieved. Therefore, when using a compensator having no hybrid orientation, for example, a tilt orientation, at least two compensating plates are laminated and used.
Specifically, a pseudo hybrid orientation is formed by a method of stacking (a) and (b) of FIG. If a compensator having a hybrid orientation is not used, the compensating effect cannot be improved unless the above conditions are satisfied by such a method.

Next, the film thickness of the compensator needs to be controlled in relation to the intrinsic birefringence value of the liquid crystal. The unique birefringence value (hereinafter also referred to as Δn) as used herein means that the thin film made of the discotic liquid crystal material constituting the compensating plate obtained by the manufacturing method of the present invention has a director in an extremely small area. The refractive index in the vertical direction (hereinafter also referred to as no) and the refractive index in the direction parallel to the director (hereinafter ne
It is also called). Such a refractive index can be obtained by utilizing the fact that the Abbe refractometer has a property of providing information in the vicinity of the measurement interface even if the structure has a structure in which the refractive index continuously changes.

It can also be obtained by measuring a sample in which a discotic liquid crystal material is sandwiched between two substrates having the same interface to suppress the hybrid orientation form and the director is oriented so as to be oriented in one direction. . The absolute value of the product of the intrinsic birefringence value thus obtained and the absolute film thickness of the thin film made of the discotic liquid crystal material constituting the compensator is 20 nm or more when compensating for a TN mode display. The range is 1000 nm or less,
It is preferably 50 nm or more and 600 nm or less, particularly preferably 100 nm to 400 nm or less.
Within this range, the compensator obtained by the manufacturing method of the present invention exhibits a sufficient compensating effect. When it is less than 20 nm, there is a possibility that the viewing angle characteristics of the liquid crystal display can hardly be changed. On the other hand, when it exceeds 1000 nm, unnecessary coloring may occur in the liquid crystal display. Incidentally, the compensator obtained by the manufacturing method of the present invention, it is also possible to use a plurality of thin films made of a discotic liquid crystal material or a plurality of compensating plates themselves obtained by the manufacturing method, in which case, The absolute value of the product of the intrinsic birefringence value and the absolute film thickness of each thin film made of the discotic liquid crystal material is preferably within these ranges. When compensating for OCB mode display, the above value is usually 50 nm or more and 200 n
m or less is preferable.

Next, the apparent in-plane retardation value on the front surface will be described. In the hybrid orientation, since the director is not generally in the direction perpendicular to the thin film plane, apparent birefringence occurs when observed from the direction perpendicular to the thin film plane. The direction obtained when the director is projected in the plane of the thin film made of the discotic liquid crystal material is apparently the fast axis, and the direction in the plane perpendicular thereto is the slow axis. The apparent retardation value on the front side can be easily obtained by polarization optical measurement such as ellipsometry. The apparent retardation value in a thin film made of a discotic liquid crystal material constituting the compensator of the present invention is usually in the range of 5 nm to 500 nm, more preferably, for monochromatic light of 550 nm when compensating for a TN mode display. In the range of 10 nm to 300 nm, particularly preferably 1
It is in the range of 5 nm to 150 nm. If the apparent retardation value is less than 5 nm, the compensation effect may not be expected so much. On the other hand, if the thickness is larger than 500 nm, unnecessary coloring may occur in the TN mode liquid crystal display when viewed obliquely. When a plurality of compensating plates of the present invention are used, the absolute value of the apparent retardation value of each thin film is preferably within these ranges. When compensating for OCB mode displays, the above values are usually 10 nm to 800 nm.
The range of nm is preferred.

Next, an apparent average tilt angle is given as a parameter. This is the average value of the angle formed by the director of the discotic liquid crystal with the substrate normal. This can be obtained by applying the crystal rotation method, which is effective for analyzing the crystal structure. The measuring method is as follows. First, the compensator of the present invention is sandwiched between orthogonal polarizers. However, the arrangement is such that the projection vector of the director of the discotic liquid crystal and the transmission axis of the polarizer are 45
Make an angle of degrees. Then, the thin film on the substrate is tilted together with the substrate along the projection vector direction of the director of the discotic liquid crystal on the substrate surface, and the transmittance is measured. The average tilt angle is calculated from the relationship between the tilt angle and the transmittance of the thin film made of the discotic liquid crystal material.

The polarizer is placed on the side closer to the light source than the compensator.
A method in which only one sheet is placed and the apparent retardation value is obtained by polarization analysis of the emitted light can be similarly adopted.
However, a compensator having a thin film made of a discotic liquid crystal material having a hybrid orientation as a constituent member is not completely equivalent to a negative uniaxial structure in which the optical axis is in a fixed direction.
That is, in the negative uniaxial structure, there is generally a tilt angle at which the transmittance falls to almost zero, which corresponds to the fact that the incident light travels along the optical axis of the sample (however, the light at the thin film interface is Consider the refraction of). On the other hand, in the hybrid orientation, since there is no optical axis, there is no tilt angle at which the transmittance becomes zero. Therefore, the tilt angle of the uniform tilt orientation in which the curvature of the curve showing the relationship between the minimum value of the transmittance or the transmittance and the tilt angle is the closest is the average tilt angle of the thin film in which the hybrid orientation is formed. The average tilt angle thus obtained is usually in the range of 2 to 60 degrees, preferably in the range of 5 to 50 degrees, and more preferably in the range of 10 to 45 degrees.
When the average tilt angle is less than 2 degrees, there is a possibility that the compensation effect may not be exhibited so much. Further, when the average tilt angle exceeds 60 degrees, the average refractive index in the thickness direction becomes too large as compared with that in the plane, and the compensation effect may not be sufficiently obtained.

As described above, the optical parameters and physical property values that can be described in detail are the structures of the compensating plate having a thin film made of a discotic liquid crystal material as a constituent member when the hybrid alignment obtained by the manufacturing method of the present invention is formed. The angle, the film thickness, the in-plane apparent retardation value, and the average tilt angle have been described. It is naturally preferred that all of the above values be measurable and be within the preferred ranges for each. However, depending on the form of the compensator, it may be difficult to measure all of them. In such a case, since these values are correlated with each other, it is practically acceptable if at least two of them are measured and are within the above-described preferable ranges. For example, when the same liquid crystal material is used and aligned by a similar method, in the present invention, the director angle at the thin film interface and the average tilt angle are generally constant regardless of the film thickness, and the retardation value is the film thickness. Proportional to.

As described above, the use of one or more compensators of the present invention makes it possible to view various liquid crystal displays such as normally white mode TN liquid crystal display and OCB mode liquid crystal display. Greatly effective in improving corners. A conventional compensator (compensation element) made of liquid crystal polymer, for example, an optical film having a negative uniaxial refractive index structure, an optical film having a positive uniaxial refractive index structure, or a biaxial refractive index structure It is also possible to use it in combination with an optical film or the like. Further, it can be used as a polarizing plate in combination with a polarizing plate having improved viewing angle dependency. However, it is the compensator obtained by the manufacturing method of the present invention that plays a decisive role for compensation, and only the compensator (compensation element) made of the conventional liquid crystal polymer was used in any combination. Even in this case, it is impossible to exhibit an excellent compensation effect like the compensator obtained by the manufacturing method of the present invention.

As described above, by providing various liquid crystal displays with the compensating plate obtained by the manufacturing method of the present invention, little change in color or change in light and dark depending on the viewing angle is hardly felt. Further, even when the area of the display is enlarged, it is possible to display the same in the central portion and the peripheral portion of the screen.

In the compensating plate obtained by the manufacturing method of the present invention, when the thin film made of the discotic liquid crystal material forming the compensating plate is made into the thin film in which the hybrid alignment is formed, the thin film is hybrid alignment. The upper and lower sides of the compensator are not equivalent, and a slight difference in compensation effect can be seen depending on which side is closer to the driving liquid crystal cell. Further, in the compensator, the angle formed by the director of the liquid crystal near the interface with the plane of the film is 60 degrees or more and 90 degrees or less on one of the upper surface and the lower surface of the film, and 0 on the opposite surface. It is not less than 50 degrees and not more than 50 degrees, and either surface may be closer to the liquid crystal cell, but the surface formed by the director at a larger angle with the film plane (the surface having an angle between 60 degrees and 90 degrees) is driven. It is desirable to install the liquid crystal cell close to the liquid crystal cell and away from the polarizing plate.

[0075]

The present invention will be described in more detail with reference to the following examples, which should not be construed as limiting the invention thereto.
The analytical methods used in Preparation Examples and Examples are as follows. (Optical microscope observation) Polarizing microscope BX- manufactured by Olympus
50 was used for orthoscopic observation and conoscopic observation. The liquid crystal phase was identified by observing the texture while heating it on a METTLER HOT stage (FP-80). (Polarization analysis) Ellipsometer DV manufactured by Mizojiri Optical Industry Co., Ltd.
It was performed using A-36VWLD. (Measurement of Refractive Index) Atago Abbe Refractometer Type-4
Performed using T. (Film thickness measurement) Kosaka Laboratory's high-precision thin film level difference measuring device E
T-10 was mainly used. Further, an interference wave measurement (UV-visible / near-infrared spectrophotometer V-570 manufactured by JASCO) and a method of obtaining the film thickness from the data of the refractive index were also used.

Preparation of Discotic Liquid Crystal Material (Preparation Example 1) Hexahydroxytriphenylene 50 m
mol, 4-butoxybenzoic acid 100 mmol, 4-
Hexyloxybenzoic acid 100 mmol, 4-octyloxybenzoic acid 100 mmol, acetic anhydride 150
The mixture of 0 mmol was charged into a glass container having a capacity of 500 ml equipped with a mechanical stirrer, and under a nitrogen atmosphere, 1
Heated at 20 ° C. for 1 hour. Subsequently, the temperature was raised to 260 ° C. over a period of 1 hour while distilling off the acetic acid by-produced and unreacted acetic anhydride. The reaction product was sampled at a reaction temperature of about 200 ° C., and the reaction product was measured by high performance liquid chromatography (HPLC) (column: Z manufactured by DuPont).
orvax ODS 4.6 × 250 mm, mobile phase: C
H ₃ CN / H ₂ O / H ₃ PO ₄ = 60/40 / 0.1,
Flow rate: 1.0 ml / min, retention time: 8.3 mi
n). As a result of the measurement, almost no hexahydroxytriphenylene was confirmed, and production of hexaacetoxytriphenylene, which is an acetylated product of hexahydroxytriphenylene, was confirmed. After the temperature was raised to 260 ° C., the mixture was reacted at the same temperature for 2 hours and then reacted at 280 ° C. for 8 hours under a nitrogen stream of 50 ml / min to obtain a discotic liquid crystal material (Material 1). The isotropic transition temperature of this material is 280 ℃
Met.

Preparation Example 2 Hexahydroxytriphenylene 50 mmol, 4-tert-butylbenzoic acid
145 mmol, 4-heptyloxybenzoic acid 145
A mixture of mmol and acetic anhydride 1500 mmol was charged into a glass container having a capacity of 500 ml equipped with a mechanical stirrer and heated at 120 ° C. for 1 hour under a nitrogen atmosphere. Subsequently, the temperature was raised to 250 ° C. over a period of 1 hour while distilling off by-produced acetic acid and unreacted acetic anhydride. Reaction temperature 2
The reaction product was sampled at around 00 ° C., and the reaction product was measured by high performance liquid chromatography (HPLC) (column: DuPont Zorvax ODS).
4.6 × 250 mm, mobile phase: CH ₃ CN / H ₂ O / H
₃ PO ₄ = 60/40 / 0.1, flow rate: 1.0 ml / m
in, retention time: 8.3 min). As a result of the measurement, almost no hexahydroxytriphenylene was confirmed, and production of hexaacetoxytriphenylene, which is an acetylated product of hexahydroxytriphenylene, was confirmed. 250
After heating up to ℃, react at the same temperature for 3 hours, then 50ml /
A discotic liquid crystal material (material 2) was obtained by reacting at 260 ° C. for 8 hours under a nitrogen stream for a minute. The isotropic transition temperature of this material was 267 ° C.

(Preparation Example 3) Hexahydroxytriphenylene 50 mmol, 4-tert-butylbenzoic acid
A mixture of 112 mmol, stearic acid 112 mmol, sebacic acid 40 mmol, acetic anhydride 1500 mmol, and a capacity of 500 m equipped with a mechanical stirrer.
It was placed in a glass container of 1 l, and it was 1 at 120 ° C under a nitrogen atmosphere.
Heated for hours. Subsequently, the temperature was raised to 250 ° C. over a period of 1 hour while distilling off by-produced acetic acid and unreacted acetic anhydride.
The reaction product was sampled at a reaction temperature of about 200 ° C. and the reaction product was subjected to high performance liquid chromatography (HPL).
C) (column: Zorva manufactured by DuPont)
x ODS 4.6 × 250 mm, mobile phase: CH ₃ CN
/ H ₂ O / H ₃ PO ₄ = 60/40 / 0.1, flow rate:
1.0 ml / min, holding time: 8.3 min). As a result of the measurement, almost no hexahydroxytriphenylene was confirmed, and production of hexaacetoxytriphenylene, which is an acetylated product of hexahydroxytriphenylene, was confirmed. After the temperature was raised to 250 ° C., the reaction was performed at the same temperature for 3 hours, the temperature was raised to 280 ° C., the reaction was performed for 3 hours, and then the discotic liquid crystal material (material 3) was heated at 280 ° C. for 1 hour under a reduced pressure of 1 mmHg. Obtained. The isotropic transition temperature of this material was 281 ° C.

Preparation Example 4 Hexahydroxytripheni
Ren 50 mmol, 4-tert-butylbenzoic acid
75 mmol, 4-pentylbenzoic acid 75 mmol,
4-hexyloxybenzoic acid 75 mmol, 4-hep
Tyloxybenzoic acid 80 mmol, acetic anhydride 150
0 mmol mixture was equipped with mechanical stirrer
Charge in a glass container with a capacity of 500 ml, and under a nitrogen atmosphere,
Heated at 120 ° C. for 1 hour. Then take an hour
Distilled off acetic acid and unreacted acetic anhydride to 250 ° C.
The temperature rose. When the reaction temperature is around 200 ° C, the reaction product
Ring and perform high performance liquid chromatography of the reaction product.
Measured by (HPLC) (column: Z manufactured by DuPont)
orvax ODS 4.6 × 250 mm, mobile phase: C
H_ThreeCN / H_TwoO / H _ThreePO_Four= 60/40 / 0.1,
Flow rate: 1.0 ml / min, retention time: 8.3 mi
n). As a result of measurement, hexahydroxytriphenylene
Is almost not confirmed, and hexahydroxytriphenylene
Of the acetylated hexaacetoxytriphenylene
Generation was confirmed. After heating up to 250 ° C, at the same temperature
After reacting for 3 hours, react at 290 ° C for 8 hours
A liquid crystal material (material 4) was obtained. Isot of this material
The ropic transition temperature was 284 ° C.

Preparation Example 5 Hexahydroxytripheni
Ren 50 mmol, 6-hexyloxy-2-naphtho
150 mM enoic acid, 4-pentyloxybenzoic acid
A mixture of 150 mmol and acetic anhydride 1500 mmol
With a mechanical stirrer and a capacity of 500 ml.
Place in a lath container and heat at 110 ° C for 2 hours in a nitrogen atmosphere.
Heated. Then, over a period of 1.5 hours, acetic acid produced as
The temperature was raised to 250 ° C while the reaction acetic anhydride was distilled off. Anti
The reaction product is sampled at a temperature of around 200 ° C,
The reaction product was analyzed by high performance liquid chromatography (HPLC).
Measured (column: Zorvax O manufactured by DuPont)
DS 4.6 x 250 mm, mobile phase: CH_ThreeCN / H _Two
O / H_ThreePO_Four= 60/40 / 0.1, flow velocity: 1.0 m
l / min, holding time: 8.3 min). Measured result
As a result, hexahydroxytriphenylene was almost confirmed.
Without acetylated hexahydroxytriphenylene
The formation of certain hexaacetoxytriphenylene was confirmed
Was. After heating to 250 ° C., reacting at the same temperature for 3 hours,
Reaction is performed at 260 ° C for 6 hours under a nitrogen stream of 50 ml / min.
A discotic liquid crystal material (material 5) was obtained. This material
The isotropic transition temperature of the material was 284 ° C.

Preparation Example 6 Hexahydroxytriphenylene 50 mmol, 4-heptyloxybenzoic acid 2
A mixture of 80 mmol, 10 mmol of terephthalic acid, and 1500 mmol of acetic anhydride was charged into a glass container having a capacity of 500 ml equipped with a mechanical stirrer, which was first heated at 125 ° C. for 1 hour under a nitrogen atmosphere, followed by acetic acid and unproduced by-products over 2 hours. While distilling off the reaction acetic anhydride 2
The temperature was raised to 40 ° C. The reaction product was sampled at a reaction temperature of about 200 ° C., and the reaction product was measured by high performance liquid chromatography (HPLC) (column: DuPon.
Zorvax ODS 4.6 × 250 mm manufactured by t company, mobile phase: CH ₃ CN / H ₂ O / H ₃ PO ₄ = 60/40 /
0.1, flow rate: 1.0 ml / min, retention time: 8.3
min). As a result of the measurement, almost no hexahydroxytriphenylene was confirmed, and production of hexaacetoxytriphenylene, which is an acetylated product of hexahydroxytriphenylene, was confirmed. After the temperature was raised to 240 ° C., the reaction was carried out at the same temperature for 3 hours and then the temperature was raised to 280 ° C. and the reaction was carried out for 6 hours to obtain a discotic liquid crystal material (material 6). The isotropic transition temperature of this material was 235 ° C.

Preparation Example 7 Hexahydroxytripheni
Ren 5 mmol, 4'-heptyloxy [1,1'-
Biphenyl] -4-carboxylic acid 7 mmol, 4-hex
Syloxybenzoic acid 19 mmol, 4,4 '-(ethane
N-1,2-diylbisoxy) bisbenzoic acid 2 mm
ol, acetic anhydride 150 mmol was used, and this was used as volume 2
Place in a 00 ml glass container, and under a nitrogen atmosphere, 125
Heat at 45 ° C for 45 minutes. Acetic acid produced as a by-product over 1 hour
And distilling off unreacted acetic anhydride while raising the temperature to 250 ° C.
did. Sampling of reactants at reaction temperature around 200 ℃
Then, the reaction product was subjected to high performance liquid chromatography (HP
LC (column: DuPont Zorv)
ax ODS 4.6 × 250 mm, mobile phase: CH_ThreeC
N / H_TwoO / H_ThreePO _Four= 60/40 / 0.1, flow rate:
1.0 ml / min, holding time: 8.3 min). Measurement
As a result, hexahydroxytriphenylene was almost confirmed
Acetylation of hexahydroxytriphenylene
Generation of hexaacetoxytriphenylene, which is a substance
Was done. After heating up to 250 ° C, react at the same temperature for 3 hours
After that, the reaction was performed for 6 hours under a nitrogen stream of 20 ml / min, and the reaction was performed.
A scotic liquid crystal material (material 7) was obtained. This material
The isotropic transition temperature was 282 ° C.

Preparation Example 8 Hexahydroxytriphenylene 50 mmol, 4-octyloxybenzoic acid 1
20 mmol, 6-pentyloxy-2-naphthoic acid
A mixture of 180 mmol and 2000 mmol of acetic anhydride was placed in a glass container having a capacity of 500 ml equipped with a mechanical stirrer, and heated at 120 ° C. for 1 hour under a nitrogen atmosphere. Subsequently, the temperature was raised to 250 ° C. over 1 hour while distilling off the acetic acid by-produced and unreacted acetic anhydride. The reaction product was sampled at a reaction temperature of about 200 ° C., and the reaction product was measured by high performance liquid chromatography (HPLC) (column: Zorvax ODS manufactured by DuPont).
4.6 × 250 mm, mobile phase: CH ₃ CN / H ₂ O /
H ₃ PO ₄ = 60/40 / 0.1, flow rate: 1.0 ml /
min, holding time: 8.3 min). As a result of the measurement, almost no hexahydroxytriphenylene was confirmed, and production of hexaacetoxytriphenylene, which is an acetylated product of hexahydroxytriphenylene, was confirmed. 25
After warming up to 0 ℃, react at the same temperature for 2 hours, then 50ml
The mixture was allowed to react at 280 ° C. for 6 hours under a nitrogen gas flow of 1 minute to obtain a discotic liquid crystal material (Material 8). The isotropic transition temperature of this material was 283 ° C.

Preparation Example 9 Hexahydroxytriphenylene 50 mmol, 4-hexylbenzoic acid 220 m
mol, 4-heptylbenzoic acid 75 mmol, adipic acid 5 mmol, and acetic anhydride 1600 mmol were used to carry out a reaction in the same manner as in Example 5 to obtain a discotic liquid crystal material (material 9). The isotropic transition temperature of this material was 277 ° C.

Preparation Example 10 Hexahydroxytriphenylene 50 mmol, 3-heptyloxybenzoic acid
200 mmol, 6-heptyloxy-2-naphthoic acid 100 mmol, and acetic anhydride 1400 mmol were placed in a glass container having a capacity of 500 ml equipped with a mechanical stirrer, and first heated at 120 ° C. for 1 hour under a nitrogen atmosphere. Subsequently, the temperature was raised to 250 ° C. over 1 hour while distilling off the acetic acid by-produced and unreacted acetic anhydride. Reaction temperature 2
The reaction product was sampled at around 00 ° C., and the reaction product was measured by high performance liquid chromatography (HPLC) (column: DuPont Zorvax ODS).
4.6 × 250 mm, mobile phase: CH ₃ CN / H ₂ O / H
₃ PO ₄ = 60/40 / 0.1, flow rate: 1.0 ml / m
in, retention time: 8.3 min). As a result of the measurement, almost no hexahydroxytriphenylene was confirmed, and production of hexaacetoxytriphenylene, which is an acetylated product of hexahydroxytriphenylene, was confirmed. 250
After heating up to ℃, react at the same temperature for 2 hours, then 50ml /
A discotic liquid crystal material (Material 10) was obtained by reacting at 280 ° C. for 6 hours under a nitrogen stream for a minute. The isotropic transition temperature of this material was 270 ° C.

Preparation Example 11 Hexahydroxytriphenylene 50 mmol, 6-hexyloxy-2-naphthoic acid 250 mmol, 4-heptyloxycinnamic acid
Using 50 mmol and 1200 mmol of acetic anhydride, a reaction was performed in the same manner as in Example 5 to obtain a discotic liquid crystal material (Material 11). Material 11 had an isotropic transition temperature of 265 ° C.

(Proof of being a discotic liquid crystal) The discotic liquid crystal material obtained as described above was observed on a hot plate under a polarizing microscope, and as a result, M
ol. Cryst. Liq. Cryst. , 106 , 1
21-146, 1984 (C. Destrade et al.), A schlieren texture similar to that shown in the photograph was observed to confirm the presence of a discotic nematic phase. All the liquid crystal materials obtained in Preparation Examples 1 to 11 became an isotropic phase when the temperature was further raised from the state of the discotic nematic phase. This temperature was defined as the isotropic transition temperature.

Example 1 Material 1 (5 g) was dissolved in 45 g of chloroform to prepare a 10% by weight solution. This solution was applied to a 30 cm square rubbed polyimide film by a printing method. Then, it was dried on a hot plate at 80 ° C., heat-treated at 230 ° C. for 20 minutes in an oven, taken out at room temperature and cooled, and the material 1 was first orientation-fixed on the polyimide film to obtain a compensating plate 1. Next, an ultraviolet curable adhesive was applied on the compensator 1, laminated with a triacetyl cellulose film which is a translucent film, and irradiated with light from a high pressure mercury lamp to cure the adhesive. Next, the polyimide film was peeled off and removed. The compensator 1 was on the triacetyl cellulose film via an adhesive, and a colorless and transparent laminate 1 consisting of compensator 1 / adhesive / triacetyl cellulose was obtained. When the polarization analysis of the laminate 1 was performed using an ellipsometer, the apparent retardation value in the front was 48.
was nm. The apparent fast axis was in the in-plane direction of the compensation plate parallel to the rubbing direction of the polyimide film before peeling. Next, the laminated body 1 is sandwiched between the orthogonal polarizers, and the projection vector of the liquid crystal in the compensating plate on the compensating plate surface and the transmission axis of the polarizer are arranged at an angle of 45 degrees. The laminate 1 was tilted along the direction of the projection vector of the director on the compensating plate surface (corresponding to the direction corresponding to the rubbing direction), and the apparent retardation value was measured. As shown in FIG. 4, the change in retardation is asymmetrical to the left and right, and the retardation value does not become zero at the minimum value. From these facts, the discotic liquid crystal in the compensator is shown in FIG. It was found that a hybrid orientation in which the orientation direction differs in the thickness direction, as shown in the model (c), was adopted. Further, the change in retardation in FIG. 2 was simulated by a computer, and a result of an average tilt angle of 52 degrees was obtained. The refractive index of the discotic liquid crystal was no = 1.64 ne = 1.53.

(Example 2) Material 2 (500 g) was added to 4.5
A 10 wt% solution was prepared by dissolving it in kg of a phenol / tetrachloroethane mixed solvent (weight ratio 6/4). As the orientation substrate, a polyether ether ketone film having a width of 40 cm and a length of 500 m was selected, and this film was rubbed along the longitudinal direction of the film. The solution of the material 2 was continuously coated on the rubbing-treated polyether ether ketone film by the roll coating method. Then 8
After removing most of the solvent with hot air at 0 ° C, the liquid crystal was aligned at a conveying speed of 1 m / min (processing time 10 minutes) into a heat treatment furnace having a length of 10 m and set at 220 ° C, and the liquid crystal was aligned at room temperature. The liquid crystal alignment was fixed by cooling with. The thickness of the compensation plate 2 was 1.5 μm. Then, a thermosetting adhesive was applied on the compensator, and then laminated with a transacetylation film, triacetyl cellulose film, and heated at 90 ° C. for 1 hour to cure the adhesive. Next, the polyether ether ketone was peeled off and removed. The compensator 2 was on the triacetyl cellulose film via an adhesive, and a colorless and transparent laminate 2 composed of compensator 2 / adhesive / triacetyl cellulose was obtained. When polarization analysis of the compensator 2 was performed using an ellipsometer, first, the apparent retardation value in the front was 54 nm. The apparent fast axis was in the longitudinal direction of the film. Next, the laminated body 2 is sandwiched between orthogonal polarizers, and the liquid crystal in the compensator is arranged so that the projection vector of the director on the compensator surface and the polarizer transmission axis form an angle of 45 degrees. The laminate 2 was tilted along the direction of the projection vector of the director on the compensating plate surface (corresponding to the direction corresponding to the rubbing direction), and the apparent retardation value was measured. The results of FIG. 3 were obtained, and the discotic liquid crystal had a hybrid orientation, and the average tilt angle was 23 degrees. Next, using two laminates 2, the effect of improving the viewing angle for a TN cell (90 degree twist, retardation 480 nm) was examined. The laminate 2 was sandwiched between the upper and lower polarizing plates of the TN cell in the arrangement shown in FIG. 4 to measure the contrast. As a result, as shown in FIG. 5, it was found that in the liquid crystal display device using the laminated body 2, the region having a contrast ratio of 100 or more spreads widely as compared with the case where the laminated body 2 is not provided.

Example 3 A xylene solution containing 10% by weight of Material 3 was prepared and applied on a glass substrate (30 cm square, thickness 1.1 mm) having a rubbing polyimide film by a printing method. Then, it was air-dried, heat-treated at 200 ° C. for 30 minutes, and then cooled and fixed at room temperature. Compensation plate 3 obtained
Was transparent and had no alignment defects, and the film thickness of the compensator was 3.2 μm. According to the refractive index measurement, the director of the liquid crystal is almost perpendicular to the substrate at the interface of the alignment substrate and substantially parallel to the substrate at the air interface side, and ne = 1.65 no = 1.55.
Met. From this, the refractive index difference between no and ne was 0.10, and the product of this and the film thickness was 320 nm. The in-plane apparent retardation value was 180 nm, and the slow axis was in the in-plane direction perpendicular to the rubbing direction. Further, the compensator 3 was tilted along the rubbing direction in the same manner as in Example 1 to measure the apparent retardation value, and the average tilt angle was 41 degrees. Similar to Examples 1 and 2,
The compensating plate 3 exhibited a good viewing angle improving effect on the TN cell.

Example 4 Material 4 (8 g) was dissolved in 92 g of chloroform to prepare an 8 wt% solution, which was applied onto a 15 cm square glass substrate having a rubbing polyimide film by spin coating, and then at 50 ° C. After being dried on a hot plate of No. 1, heat-treated at 250 ° C. for 15 minutes in an oven, taken out at room temperature and cooled to obtain a compensating plate 4. The film thickness of the compensator 4 was 2.0 μm. The birefringence was 0.11 as measured by the refractive index, and the product of this and the film thickness was 2
It became 20 nm. When ellipsometer was used for ellipsometry, the apparent retardation in the front was 95 nm. The fast axis is the rubbing direction and 8
There was an in-plane direction of the film deviated. Similar to Examples 1 and 2, the compensator 4 exhibited a good viewing angle improving effect on the TN cell.

(Example 5) 182 g of the material 5 (18 g)
Was dissolved in chloroform to prepare a 9% by weight solution, and the material 5 solution was applied onto a 15 cm square glass substrate having a rubbing polyimide film by spin coating. Then 5
Dry on a hot plate at 5 ℃ and 230 ℃ in an oven.
After heat-treating for 20 minutes at room temperature, remove to room temperature and cool,
The compensator 5 was obtained. The film thickness of the compensator 5 was 4.0 μm. The birefringence was 0.13 as measured by the refractive index, and the product of this and the film thickness was 520 nm. When ellipsometer was used for ellipsometry, the apparent retardation in the front was 185 nm. The fast axis was in the in-plane direction deviated by 3 ° from the rubbing direction.
Also, as in Example 1, the apparent retardation value was measured by tilting along the rubbing direction, and the average tilt angle was 35.
I got the result. Similar to Examples 1 and 2, the compensator 5 exhibited a good viewing angle improving effect on the TN cell.

Example 6 180 g of Material 6 (20 g)
Was dissolved in chloroform to prepare a 10% by weight solution. Then, the material 6 solution was applied on a 15 cm square glass substrate having a rubbing polyimide film by a spin coating method, and then dried on a hot plate at 65 ° C. Then, after heat-treating at 226 ° C. for 25 minutes in an oven, it was taken out at room temperature and cooled to obtain a compensating plate 6 on a transparent substrate. The film thickness of the compensator 6 was 5.5 μm. The birefringence was 0.08 as measured by the refractive index, and the product of this and the film thickness was 440 nm. When ellipsometer was used for ellipsometry, the apparent retardation in the front was 35 nm. The fast axis was in the in-plane direction deviated from the rubbing direction by 2 °. Also, as in Example 1, the apparent retardation value was measured while tilting along the rubbing direction, and the result was that the average tilt angle was 15 degrees. As in the first and second embodiments, the compensator 6 has a T
A good viewing angle improving effect was exhibited for the N cell.

Example 7 Material 7 (2.5 g) was added to 17.
The solution was dissolved in 5 g of dimethylformamide to prepare a 12.5% by weight solution. Then, the material 7 solution was applied onto a 15 cm square glass substrate having a rubbing polyimide film by spin coating, and then dried on a hot plate at 70 ° C. After drying, it was heat-treated in an oven at 235 ° C. for 18 minutes, taken out at room temperature and cooled to obtain a compensating plate 7. The film thickness of the compensator 7 was 3.8 μm. The birefringence was 0.11 as measured by the refractive index, and the product of this and the film thickness was 420 nm. When ellipsometer was used to perform ellipsometry, the apparent retardation in the front was 180 nm. The fast axis was in the in-plane direction, which was offset by 4 ° from the rubbing direction. Also, as in Example 1, the apparent retardation value was measured while tilting along the rubbing direction, and the average tilt angle was 40 degrees. Similar to Examples 1 and 2, the compensator 7 exhibited a good viewing angle improving effect on the TN cell.

Example 8 Material 8 (5 g) was dissolved in 95 g of toluene to prepare a 5% by weight solution. Then, the material 8 solution was applied by a spin coating method onto a 15 cm square glass substrate having a rubbing polyimide film, and then 6
It was dried on a hot plate at 3 ° C. After drying, it was heat-treated in an oven at 215 ° C. for 15 minutes, taken out at room temperature and cooled to obtain a compensating plate 8. The thickness of the compensator 8 is 0.8
μm. The birefringence is 0.10 according to the refractive index measurement.
And the product of this and the film thickness was 80 nm. When ellipsometer was used for ellipsometry, the apparent retardation on the front was 60 nm. The fast axis and the rubbing direction were the same direction and were in the in-plane direction of the film. Further, as in Example 1, the apparent retardation value was measured while tilting along the rubbing direction, and the result was that the average tilt angle was 60 degrees. Examples 1 and 2
Similarly, the compensator 8 exhibited a good effect of improving the viewing angle for the TN cell.

Example 9 Material 9 (20 g) was dissolved in 80 g of chloroform to prepare a 20% by weight solution.
Then, the material 9 solution was applied onto a 15 cm square glass substrate having a rubbing polyimide film by a spin coating method, and then dried on a hot plate at 55 ° C. After drying, it was heat-treated in an oven at 226 ° C. for 35 minutes, taken out at room temperature and cooled to obtain a compensating plate 9. The film thickness of the compensator 9 was 11.0 μm. The birefringence was 0.09 as measured by the refractive index, and the product of this and the film thickness was 990 nm.
It became. Next, when polarization analysis of the compensator 9 was performed using an ellipsometer, first, the apparent retardation on the front side was 35 nm. The fast axis was in the in-plane direction deviated from the rubbing direction by 1 °. Further, as in Example 1, the apparent retardation value was measured while tilting along the rubbing direction, and the average tilt angle was 10 degrees. As in the first and second embodiments, the compensator 9 is a TN.
A good viewing angle improving effect was exhibited for the cell.

Example 10 96 g of the material 10 (4 g)
Was dissolved in chloroform to prepare a 4% by weight solution. Then, the material 10 solution was applied onto a 15 cm square glass substrate having a rubbing polyimide film by spin coating, and then dried on a hot plate at 65 ° C. After drying, it was heat-treated in an oven at 210 ° C. for 10 minutes, taken out at room temperature and cooled to obtain a compensating plate 10. Compensation plate 1
The film thickness of 0 was 0.5 μm. The birefringence was 0.07 as measured by the refractive index, and the product of this and the film thickness was 35 nm.
It became. Further, when polarization analysis was performed using an ellipsometer, the apparent retardation on the front side was 20 nm. The fast axis was in the in-plane direction, which was offset by 8 ° from the rubbing direction. Also, as in Example 1, the apparent retardation value was measured while tilting along the rubbing direction, and the average tilt angle was 48 degrees. Similar to Examples 1 and 2, the compensator 10 exhibited a good viewing angle improving effect on the TN cell.

Example 11 93 g of the material 11 (7 g)
Was dissolved in chloroform to prepare a 7% by weight solution. Next, the material 11 solution was applied on a 15 cm square glass substrate having a rubbing polyimide film by spin coating, and then dried on a hot plate at 63 ° C. After drying, it was heat-treated in an oven at 235 ° C. for 15 minutes, taken out at room temperature and cooled to obtain a compensating plate 11. Compensation plate 1
The film thickness of 1 was 2.3 μm. Further, the birefringence was 0.10 as measured by the refractive index, and the product of this and the film thickness was 230 n.
m. When ellipsometer was used for ellipsometry, the apparent retardation on the front was 55 nm. The fast axis was in the in-plane direction, which was offset by 5 ° from the rubbing direction. Also, as in Example 1, the apparent retardation value was measured while tilting along the rubbing direction, and the average tilt angle was 28 degrees.
Similarly to Examples 1 and 2, the compensator 11 exhibited a good viewing angle improving effect on the TN cell.

[0099]

INDUSTRIAL APPLICABILITY The liquid crystal display element compensating plate of the present invention uses a discotic liquid crystal material which can be obtained by arbitrarily adjusting desired physical properties, for example, a liquid crystal transition point, and is therefore required in the field of liquid crystal displays. It is possible to obtain a compensator having excellent temperature characteristics such as thermal stability and high temperature reliability. In addition, since it is possible to obtain a desired liquid crystal material, according to the high performance of the liquid crystal display,
It has a high technical value, such as the ability to obtain a compensator that meets the requirements.

[Brief description of drawings]

FIG. 1 is a schematic view of an alignment form that a discotic liquid crystal material can have. The arrow in the figure means the director.
(A) is a negative uniaxial structure in which the director is perpendicular to the plane of the compensator (homeotropic alignment). (B) is a negative uniaxial structure (tilt orientation) in which the director is tilted at a constant angle with respect to the compensator plane. (C) is a hybrid orientation in which the director changes in the thickness direction of the compensator.

FIG. 2 is a measurement result of an apparent retardation value obtained in Example 1.

FIG. 3 is a measurement result of an apparent retardation value obtained in Example 2.

FIG. 4 is a perspective view of a liquid crystal display device used in Example 2. 1. Polarizing plate 2. Laminated body 2 3. Alignment-fixed discotic liquid crystal material layer 4. 4. Triacetyl cellulose film having an adhesive layer 5. TN liquid crystal cell 6. Transmission axis of deflector 7. Direction corresponding to rubbing direction of polyetheretherketone film 8. Rubbing direction of TN liquid crystal cell substrate

5 is a view angle characteristic obtained in Example 2. FIG. The curves in the figure show isocontrast curves with a contrast of 100. The three concentric circles have viewing angles θ = 20 degrees, 40 degrees, and 6 degrees, respectively.
A cross that represents 0 degree and is indicated by a dotted line is an azimuth angle φ = 0 degree, 9
Represents 0 degrees, 180 degrees and 270 degrees. (A) When the compensator is not used (b) When the compensator is used

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Kobori 8th Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Nippon Petroleum Co., Ltd. Central Technology Research Institute

Claims (5)

[Claims] 1. A reaction system comprising one or a plurality of planar condensed ring compounds having 6 or more phenolic hydroxyl groups in one molecule, an acetylating agent, and a plurality of carboxylic acid compounds having 6 or more carbon atoms. The acetylation reaction of the phenolic hydroxyl group is caused to occur, and the deacetic acid reaction between the acetyl group obtained by the reaction and the carboxylic acid compound coexisting in the reaction system is allowed to proceed in the same reaction system. A method for producing a compensator for a liquid crystal display device, which comprises applying a discotic liquid crystal material substantially composed of the reaction product on an alignment substrate, followed by heat treatment and cooling. 2. A discotic liquid crystal material comprising one or a plurality of planar condensed ring compounds having at least 6 phenolic hydroxyl groups in one molecule, an acetylating agent, and a plurality of carbon atoms having 6 or more carbon atoms. In the reaction with an acid compound, the reaction is carried out under reduced pressure or under an inert gas stream during the reaction time of 1/3 to 9/10 of the total reaction time from the reaction start time to the reaction end time. The method for producing a compensating plate for a liquid crystal display element according to claim 1, wherein the method comprises substantially the reaction product thus obtained. 3. A planar fused ring compound having 6 or more phenolic hydroxyl groups in one molecule is 2, 3,
The method for producing a compensating plate for a liquid crystal display device according to claim 1 or 2, which is 6,7,10,11-hexahydroxytriphenylene. 4. A plurality of carboxylic acid compounds having 6 or more carbon atoms are compounds having one carboxyl group in one molecule and / or carboxylic acid compounds having two or more carboxyl groups in one molecule. 4. The method for manufacturing a compensating plate for a liquid crystal display device according to claim 1, wherein the compensating plate is a liquid crystal display device. 5. The method for producing a compensating plate for a liquid crystal display device according to claim 1, wherein the acetylating agent is acetic anhydride.