JPH09221670A - Production of compensator for liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject compensator, excellent in thermal stability, high-temperature reliability, etc., and useful as a visibility angle improving plate or a color compensator for liquid crystal displays by applying a specific discotic liquid crystal material onto an oriented substrate, then heat-treating the coated substrate and cooling the heat-treated substrate. SOLUTION: This compensator is obtained by applying (A) a discotic liquid crystal material composed of a reactional product prepared by carrying out the deacetylating reaction of (A1 ) a planar condensed cyclic compound having >=6 phenolic acetate groups of the formula (Ar is an aromatic group capable of forming the planar condensed cyclic compound) in the molecule (e.g. 2,3,6,7,10,11-hexaacetoxytriphenylene) with (A2 ) plural kinds of >=6C carboxylic acid compounds onto (B) an oriented substrate [e.g. a poly(ether) imide, a polyphenylene sulfide or polyethylene terephthalate], heat-treating the coated substrate and then cooling the heat-treated substrate.

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, a compensating element made of a polymer has been attracting attention as a liquid crystal display is made thinner and lighter.
As a compensating element made of a polymer, there is a retardation film obtained by stretching a film of polysulfone, polycarbonate, polyvinyl alcohol or the like, which is widely used for color compensation of STN type liquid crystal displays. On the other hand, there is a compensating liquid crystal polymer film made of a main chain type liquid crystal polymer or a side chain type liquid crystal polymer. Among them, a compensating element made of a liquid crystal polymer such as liquid crystalline polyester should fix the alignment form of the liquid crystal. It is possible to simultaneously compensate the retardation and the optical rotatory dispersion, which cannot be achieved by the retardation film, due to the effect of the orientation form, and greatly contributed to the color compensation or the viewing angle compensation of the liquid crystal display (for example, JP-A-3- 87720 publication). However, with the technical progress of liquid crystal displays, the performance required for these compensating plates has become diversified and complicated. There is an increasing demand for a viewing angle compensator, a color of OCB mode liquid crystal display, and a viewing angle compensator. In the present situation, the conventional type retardation film using the stretched film and the compensator using the liquid crystal polymer cannot meet the demands. To overcome these limitations, a compensation plate using a discotic liquid crystal, which is a disk-shaped molecule and has a negative uniaxial refractive index structure, has recently been proposed. For example, JP-A-6-214116 and JP-A-7-146409 disclose a compensating plate using a discotic liquid crystal compound having the same substituent or a mixture of the compounds. The discotic liquid crystal compound is mainly composed of a disc-shaped central portion (discogen) essential for expressing the discotic liquid crystal phase and a substituent necessary for stabilizing the liquid crystal phase, but The compound obtained by forming an ester bond between a discogen having a hydroxyl group and a substituent group having a carboxylic acid group (carboxyl group) is used as an optical material. Conventionally, the method for forming the ester bond is, as described in the above publication, for example, 2,3,4
A compound having a plurality of phenolic hydroxyl groups in one molecule such as 6,7,10,11-hexahydroxytriphenylene and a carboxylic acid chloride as a raw material which can be a substituent part are formed by condensing these compounds. It was a thing. However, in this method, it is necessary to convert a carboxylic acid into a chloride using a reagent that 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. In the compensator described in the above publication, the director of the discotic liquid crystal molecule (a unit vector that specifies the orientation direction of the average optical axis of the molecule) is tilted in a certain direction to be aligned, and It is a negative uniaxial compensator with a tilted axis, that is, a refractive index structure. In this compensator, an oblique SiO vapor deposition film or a special metamorphic alignment film is used to obtain an alignment with a tilted optical axis. However, there is a manufacturing disadvantage that causes 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 a reaction product obtained by a deacetic acid reaction between at least one planar condensed ring compound having 6 or more phenolic acetate groups in one molecule and a plurality of carboxylic acid compounds having 6 or more carbon atoms. The present invention relates to a method of manufacturing a compensator for a liquid crystal display device, which comprises applying a discotic liquid crystal material, which is substantially constituted, onto an alignment substrate, followed by heat treatment and cooling. The second aspect of the present invention is that a reactor provided with an acetic acid distillation outlet for distilling acetic acid by-produced
While acetic acid is distilled from the acetic acid distillation outlet by providing at least one planar condensed ring compound having 6 or more phenolic acetate groups in the molecule and a plurality of carboxylic acid compounds having 6 or more carbon atoms The deacetic acid reaction is allowed to proceed, and the amount of acetic acid distilled from the acetic acid distillation outlet is 30% of the theoretical amount of acetic acid distillation.
From the point of acetic acid distillation corresponding to ˜95%, a discotic liquid crystal material consisting essentially of the reaction product obtained by carrying out the reaction under reduced pressure or under an inert gas stream is coated on the alignment substrate, The present invention relates to a method for manufacturing a compensating plate for a liquid crystal display element, which comprises performing heat treatment and cooling. The third aspect of the present invention is that the planar condensed ring compound having 6 or more phenolic acetate groups in one molecule is 2, 3,
6,7,10,11-Hexaacetoxytriphenylene The present invention relates to a method for producing a compensating plate for a liquid crystal display element according to the first or second aspect. Furthermore, a fourth aspect of the present invention is that a plurality of carboxylic acid compounds having 6 or more carbon atoms are
4. A plurality of kinds selected from a compound having one carboxyl group in one molecule and / or a carboxylic acid compound having two or more carboxyl groups in one molecule. The present invention relates to a method for manufacturing a compensator for a liquid crystal display device.

[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 comprises a planar condensed ring compound having 6 or more phenolic acetate groups in one molecule and carbon. It is substantially composed of a reaction product obtained by a deacetic acid reaction with a plurality of carboxylic acid compounds of several 6 or more. The reaction product is essentially composed of at least one discotic liquid crystal compound, and is composed of at least one discotic liquid crystal compound and other compounds depending on reaction conditions and kinds of raw materials. There are things. The discotic liquid crystal material used in the method for producing a compensator for a liquid crystal display device of the present invention is substantially constituted by the reaction product itself, and a compound other than the discotic liquid crystal compound is generated in the reaction product, Even if they are mixed, it is not necessary to remove them. That is, the reaction product itself exhibits discotic liquid crystallinity and is subjected to the following operation as the discotic liquid crystal material according to the present invention.

The present invention will be described in more detail below. The planar condensed ring compound having 6 or more phenolic acetate 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 developing a discotic liquid crystal phase. (Gen) is a compound that constitutes. Here, the phenolic acetate group means a group represented by the general formula (I). General formula (I)

[0007]

Embedded image

(Here, Ar means an aromatic group constituting a planar condensed ring compound.) The planar condensed ring compound means that at least three aromatic rings are contained.
It means a compound that can be condensed to be planar in terms of molecular structure. Examples of the planar condensed ring compound having a phenolic acetate group in the present invention include various compounds having a triphenylene skeleton, a torqcene skeleton, and the like.
11-hexaacetoxytriphenylene (hereinafter referred to as HAT
(Abbreviated as P) can be given as a suitable example.

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 group necessary for stabilizing the discotic liquid crystal phase. In the present invention, a carboxyl group of the compound and a phenolic acetate group of the above-mentioned planar condensed ring compound are deacetic acid to introduce a substituent formed from a carboxylic acid compound into the planar condensed ring compound. A reaction product useful as a compensator material of the invention, a discotic liquid crystal material, is obtained.

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 monofunctional carboxylic acids 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-decylbenzoic 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-methoxybenzoic acid, 2-ethoxybenzoic acid, 2-propoxy. Benzoic acid, 2-isopropoxybenzoic acid, 2-butoxybenzoic acid, 2-sec-butoxybenzoic acid, 2-isobutoxybenzoic acid, 2-ter.
t-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-diheptyloxybenzoic 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-didecyloxybenzoic 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, 3-undecyl-4-
Examples thereof include 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 compound has 11 carbon atoms.
To 41 naphthoic acid derivatives can also be preferably used. When a naphthoic 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 can be preferably used, but especially 2 A carboxyl group at the position of 6-position, a substituent at the 6-position or 7-position, and preferably a substituent at 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 compound [1,
A 1'-biphenyl] carboxylic acid derivative can also be preferably used. Alkyl group, alkoxy group, halogen, amino group,
When a [1,1′-biphenyl] carboxylic acid derivative having a substituent such as a nitro group is used, the substitution position is not particularly limited, and all isomers can be preferably used, but especially at the 4-position. Those having a carboxyl group and a substituent bonded to the 4'-position can be preferably used because of 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, as a polyfunctional carboxylic acid compound,
A difunctional carboxylic acid compound is preferably used. As this example, first, 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,
Examples thereof include dicarboxylic acid derivatives having 6 to 30 carbon atoms, preferably 6 to 20 carbon atoms such as 4'-isopropylidene bis (phenoxyacetic acid) and benzene-1,4-diyl bis (3-propenyl acid).

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. The dicarboxylic acid derivative referred to herein has the above-mentioned carbon number of 6
To 30 dicarboxylic acid derivatives are not included. Although the substitution position is not shown here, in the case of using a benzoic acid derivative, it is generally possible to use a compound in which any of the 2, 3 and 4 positions are substituted, but the 4-substituted product is most preferred because of ease of production and the like. It can be preferably used. Further, when using a naphthoic acid derivative, generally any isomer of a substituted naphthoic acid can be preferably used, but preferably, a carboxyl group at the 2-position of naphthalene is used.
The substituent is used at the 6-position or 7-position, preferably at the 6-position. Furthermore, [1,1'-biphenyl]
Regarding the 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 ones in are 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 reaction product suitable as a compensating plate material can be obtained by performing deacetic acid reaction with, for example, HATP by using plural kinds of carboxylic acid compounds as described above. Examples of combinations when using plural kinds of monofunctional carboxylic acid compounds include (1) benzoic acid derivative + naphthoic acid derivative (2) benzoic acid derivative + [1,1′-biphenyl] carboxylic acid derivative (3) benzoic acid 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 derivatives ＋ Cinnamic acid derivatives (9) Benzoic acid derivatives ＋ Naphthoic acid derivatives ＋
[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) There may be mentioned 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 Derivatives + naphthoic acid derivatives (3) Dicarboxylic acid derivatives with 6 to 30 carbon atoms + Benzoic acid derivatives + Naphthoic acid derivatives (4) Dicarboxylic acid derivatives with 6 to 30 carbon atoms + Cinnamic acid derivatives (5) 6 to 30 carbon atoms Dicarboxylic acid derivative + cinnamic acid derivative + benzoic acid derivative (6) Dicarboxylic acid derivative having 6 to 30 carbon atoms + cinnamic acid derivative + benzoic acid derivative + naphthoic acid derivative (7) Dicarboxylic acid derivative having 6 to 30 carbon atoms +
[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 in which C2-C20 organic group is sandwiched by two benzoic acid groups + benzoic acid derivative
+ Naphthoic acid derivative (13) Dicarboxylic acid derivative in which a C2-C20 organic group is sandwiched by two benzoic acid groups + Benzoic acid derivative
+ [1,1'-biphenyl] carboxylic acid derivative (14) Dicarboxylic acid derivative in which C2 to C20 organic groups are sandwiched by two benzoic acid groups + Benzoic acid derivative
+ Naphthoic acid derivative + [1,1'-biphenyl]
Carboxylic acid derivative (15) Dicarboxylic acid derivative in which C2-C20 organic group is sandwiched by two benzoic acid groups + Benzoic acid derivative
+ Naphthoic acid derivative + [1,1'-biphenyl]
Carboxylic acid derivative (16) Dicarboxylic acid derivative in which C2-C20 organic group is sandwiched by two benzoic acid groups + Benzoic acid derivative
+ Naphthoic acid derivative + [1,1'-biphenyl]
Carboxylic acid derivative + alkanoic acid (17) Dicarboxylic derivative in which C2-C20 organic group is sandwiched by two naphthoic acid groups + Benzoic acid derivative
+ Naphthoic acid derivative (18) Dicarboxylic derivative in which C2-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) [1,1'-biphenyl] Dicarboxylic acid derivative in which C2 to C20 organic groups are sandwiched by two carboxylic acid groups + Benzoic acid derivative (21) [1,1'-biphenyl] ] A dicarboxylic acid derivative in which a C2-C20 organic group is sandwiched by two carboxylic acid groups + a naphthoic acid derivative (22) [1,1'-biphenyl] C2-C20 organic group by two carboxylic acid groups Dicarboxylic acid derivative in which group is sandwiched + Benzoic acid derivative + Naphthoic acid derivative (23) [1,1′-Biphenyl] dicarboxylic acid in which organic group of C2 to C20 is sandwiched by two carboxylic acid groups Derivative + cinnamic acid derivative + naphthoic acid derivative (24) [1,1'-biphenyl] dicarboxylic acid derivative in which C2-C20 organic group is sandwiched by two carboxylic acid groups + cinnamic acid derivative + benzoic acid derivative And so on.

According to the production method of the present invention, the planar condensed ring compound described above and the carboxylic acid compound are mixed,
The deacetic acid reaction is allowed to proceed to obtain the desired reaction product as described above. The reaction product obtained by carrying out the deacetic acid reaction of the present invention is itself a preferable discotic nematic phase. Examples of the reaction product include (1) a discotic liquid crystal compound alone (2) a composition composed of two or more discotic liquid crystal compounds (3) at least one discotic liquid crystal compound and a discotic liquid crystal phase Examples thereof include compositions composed of compounds.

In the present invention, the reaction product used in the next step is a reaction product as described above or a composition comprising at least two different reaction products as described above. As will be understood from the above, when the discotic liquid crystal material of the present invention is a composition, all the compounds contained in the material need not be discotic liquid crystal compounds. Depending on the production method of the present invention, a reaction product may contain various discotic liquid crystal compounds having different distributions of substituents or compounds not exhibiting the liquid crystal phase in one reaction system. It is not necessary to analyze what kind of compound is present in the reaction product, and the whole reaction product, that is, the composition of the compound itself shows a discotic nematic phase.

The physical properties of the reaction product of the present invention, such as the phase transition temperature and the molecular orientation in the liquid crystal state, can be adjusted by selecting various planar condensed ring compounds or carboxylic acid compounds. It is also possible to obtain a reaction product having a desired phase transition temperature by the reaction conditions described later.

Next, the reaction conditions will be described. In the present invention, theoretically, the charged moles are adjusted so that the ratio of the number of moles of the phenolic acetate group contained in the planar condensed ring compound used to the number of moles of the carboxyl group contained in the carboxylic acid compound is 1. Set the ratio. However, in actual operation, it is not always necessary to accurately set the molar ratio to 1, and it is usually 0.80 to 1.20, preferably 0.9.
The ratio is set to 5 to 1.05. For example, when the raw material of the substituent group, that is, the carboxylic acid compound may be scattered out of the reaction system due to sublimation during the reaction, the carboxylic acid compound may be increased a little. Taking HATP as an example, it will be explained specifically.
It is sufficient to use 6.01 moles to 6.15 moles, preferably 6.03 moles to 6.10 moles of the carboxylic acid compound serving as a substituent with respect to 1 mole of P. If the amount of the carboxylic acid compound is too large, the unreacted carboxylic acid compound will remain in the reaction product, which may adversely affect the liquid crystallinity. On the other hand, needless to say, when it is not necessary to replace all the phenolic acetate groups of the planar condensed ring compound with the carboxylic acid compound, the substituent moiety, that is, the carboxylic acid compound can be used in a small amount. From the above, the production method of the present invention does not require an excess carboxylic acid compound as a substituent with respect to the planar condensed ring compound, and therefore a purification step such as removal of unreacted carboxylic acid compound can be performed. Not necessarily required.

It is desirable to carry out stirring during the reaction between the planar condensed ring compound and the carboxylic acid compound, but there are no particular restrictions on the stirring method, stirring speed, stirrer and stirrer blade form. The reaction temperature is usually set to 200 ° C to 300 ° C, preferably 220 ° C to 280 ° C. 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.

Usually, it is not necessary to adjust the pressure during the reaction, but it can be carried out under a pressure atmosphere of 1 atm or more, if necessary, such as when the distillation or sublimation of the raw materials is remarkable. On the other hand, when the reaction product is obtained, since the reaction is a deacetic acid reaction, acetic acid is naturally obtained as a by-product. When it is necessary to accelerate the distillation of the acetic acid or the like, 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 by-product acetic acid. 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, in the latter stage of the reaction, specifically, the amount of acetic acid by-produced (production amount) varies depending on the charged molar ratio of the raw materials, but is 30 to 95 mass of the theoretical deacetic acid distillation amount (total acetic acid production amount). % Distillation, preferably from the time of 50 to 90% by mass distillation, for the purpose of promoting the distillation of acetic acid by-produced to the outside of the reaction system and obtaining a discotic liquid crystal material having a desired liquid crystal transition point, It is preferable to carry out the reaction under reduced pressure or an inert gas stream. By performing this operation, the liquid crystal transition point can be raised. At this time, the inert gas is not particularly limited as long as it does not adversely affect the obtained liquid crystal material. Examples of the inert gas include helium, argon, methane, nitrogen, carbon dioxide, and the like, and among these, nitrogen is preferably used. In the present invention, this operation can adjust the phase transition temperature of the discotic liquid crystal material. It is not necessary to limit the flow rate of the inert gas as long as it does not inhibit the deacetic acid reaction, but it is usually [flow rate (m
1 / min) / reactor capacity (liter)]
˜1000, preferably 30 to 300. The means for measuring the amount of acetic acid by-produced is not particularly limited.
As a method for quantifying acetic acid that is usually distilled, for example, acetic acid that is distilled from the reaction vessel is aggregated by passing it through a water cooling tube,
There is a method such as collecting in a receiver and setting the amount of increase in the weight of the receiver as the amount of distilling acetic acid. The deacetic acid distillation theoretical amount is obtained by theoretically calculating from the raw materials used for the deacetic acid reaction system, that is, the charged molar ratio of the planar condensed ring compound having a phenolic acetate group and the carboxylic acid compound. To be

The 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. The form of the reactor is not particularly limited, but a reactor equipped with a distilling outlet for distilling acetic acid as a by-product is desirable. The distillation outlet may be provided with, for example, a cooling pipe, the acetic acid by-produced may be aggregated, and the deacetic acid distillation amount described above may be measured.

In order to obtain the discotic liquid crystal material of the present invention, it is not necessary to carry out a high degree of selectivity control such as introducing a specific substituent at a specific position of one discogen. In the production method of the present invention, a planar fused ring compound that gives a discogen moiety and a plurality of carboxylic acid compounds that give side chain moieties are allowed to react in a single reaction vessel to give an optical element material, specifically, compensation. A discotic liquid crystal material suitable for a plate material is obtained. At this time, there is no problem even if the compound that gives a plurality of discogen moieties and a plurality of kinds of carboxylic acid compounds are mixed and supplied to the reaction system. Of course, the discotic liquid crystal material obtained in this case is a composition of discotic liquid crystal compounds having various distributions of substituents obtained as a reaction product, but when it is used as an optical material such as a compensator, it changes from a liquid crystal phase to a crystalline phase. It is not desirable that the metastasis occurs. In that respect, it is highly preferable to use a large variety of substituents as described above, for example, to reduce the symmetry of the molecule. Furthermore, it is perfectly acceptable to mix a plurality of discotic liquid crystal compounds (reaction products) having different compositions to form a composition and use the composition as an optical material.

The discotic liquid crystal material used in the present invention has been described above in detail. When the discotic liquid crystal material is used as an optical element material such as a compensating plate,
Further purification is not necessary, but if necessary, it can be purified by a method such as reprecipitation or chromatography.

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 an alignment substrate, alignment ability, required heat resistance,
Although it cannot be generally stated because it depends on solvent resistance and the type and properties of the discotic liquid crystal material used, typical examples of the alignment substrate used are metal plates of aluminum, iron, steel, etc., ceramic plates, and enamel plates. A sheet-like or plate-like substrate made of glass or the like, and having an orientation film imparted with an orientation ability such as a rubbing-treated polyimide film, a polyvinyl alcohol film, or a silicon dioxide oblique vapor deposition film obtained by a known formulation There are things. Further, as other examples, polyimide, polyamideimide, polyetherimide, polyamide, polyetheretherketone, polyetherketone, 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 low molecular weight liquid crystals only by uniaxially stretching, 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 thickness of the thin film, and therefore 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 uniformly apply a solution in which a discotic liquid crystal material is dissolved onto an alignment substrate. To do. In the manufacturing method of the present invention, one sheet or two sheets are used.
Although one alignment substrate can be used, it is usually preferable to apply the discotic liquid crystal material using the alignment substrate and the air interface in terms of cost and simplification of the manufacturing line.

After coating, the solvent is removed and a coating film layer of a discotic liquid crystal material having a uniform film 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 coating film 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 heat treatment is performed to form a preferably uniform and monodomain thin film on the alignment substrate. 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. Usually, the heat treatment temperature is in the range of 50 to 300 ° C, and particularly preferably in the range of 100 to 270 ° C. Further, a temperature of 150 to 250 ° C. is suitable. 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, preferably 10 seconds. To 40 minutes, particularly preferably 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 onto the alignment substrate. It is also possible to perform the alignment while applying an electric field or a magnetic field to the discotic liquid crystal material layer 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. Generally, 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 at all. , Even if it has a potential crystalline phase, it has the property that the crystalline phase does not appear during cooling, or no clear crystal transition point or liquid crystal transition point is confirmed, but it does not flow within the temperature range used as a compensating element. Since it has the property that the orientation form does not change even when an external field or an external force is applied, the orientation form 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 whose morphology is easily fixed without impairing the alignment morphology, and more preferably shows a uniform and monodomain discotic nematic phase, and in the liquid crystal state, near the upper interface and near the lower interface of the compensator. The director of the discotic liquid crystal in the film thickness direction is a compensator having a hybrid orientation in which the angle between the compensator normal and the director is different between the upper interface and the lower interface of the compensator. is there. 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 have the same direction but different angles in the film thickness direction. 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 existing near the interface of the compensator and the normal to the compensator plane, that is, the normal between the director of the liquid crystal and the compensator plane. When the angle which is not on the obtuse side formed by the line (the angle within the range of 0 degree to 90 degrees) is a degree, the angle obtained by [90 degree-a degree] is the upper surface or the lower surface of the compensating plate. One side usually forms an angle of 60 degrees or more and 90 degrees or less, and the other side is usually 0 degrees or more and 50 degrees or less. More preferably, the absolute value of one angle is 80 degrees or more 9
It is 0 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 existing near the compensator interface and the compensator plane is:
0 near either the upper surface or the lower surface of the compensator
In the range of 90 degrees or more and 90 degrees or less, and on the opposite side of the surface, in the range of 0 degrees or more and 50 degrees or less, the discotic liquid crystal material to be used, the alignment substrate, and the like are appropriately selected to obtain desired angles. Can be adjusted. Further, even after the thin film is once formed, it can be adjusted to a desired angle by using a method of, for example, uniformly scraping the surface of the thin film or dipping it in a solvent to uniformly dissolve the surface of the thin film. 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,
The orientation form is maintained under the conditions of use and it can be handled like a solid. Note that 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, but is not limited thereto, and the use condition of the compensating plate for the liquid crystal display element is not limited thereto. Below, usually 0 ℃ to 50 ℃, -30 ℃ under more severe conditions
In the temperature range from 70 ° C to 70 ° C, it means that the compensator has no fluidity and that the alignment form formed in the liquid crystal state can be kept stable without changing the alignment form due to external force or external field. To do.

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 actually disposing the compensator obtained by the manufacturing method of the present invention in a liquid crystal cell, the compensator from the above-mentioned alignment substrate,
That is, it is conceivable that the thin film formed of the discotic liquid crystal material is peeled off and used as the compensator alone, or used as it is formed on the alignment substrate.

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, when the compensating plate is formed on the oriented substrate, the compensating plate can be peeled 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, it is possible to peel off the alignment substrate at the interface between the alignment substrate and the compensating plate and transfer the compensating plate to the second substrate side suitable for the compensating element to manufacture the target compensating element.

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 onto either the upper or lower glass or both sides of the glass, the incorporation of the compensating plate has already been achieved. Will be. Further, it is of course possible to manufacture the compensating plate of the present invention by using the glass or plastic substrate itself forming the display cell as an alignment substrate.

The adhesive or pressure-sensitive adhesive for sticking the second substrate and the compensating plate used for transfer is not particularly limited as long as it is an optical grade, but acrylic type, epoxy type,
An ethylene-vinyl acetate copolymer system, a rubber system, a urethane system, a mixture system thereof, or the like can be used. As the adhesive, any adhesive such as a thermosetting type, a photocuring type, and an electron beam curing type can be used without any problem as long as it has optical isotropy.

The transfer of the 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. As for the peeling method, as described above, a method of mechanically peeling using a roll or the like, a method of mechanically peeling after dipping in a poor solvent for all structural materials, and a method of peeling by applying ultrasonic waves in a poor solvent Examples include a method, a method in which a difference in thermal expansion coefficient between the alignment substrate and the compensating plate is used to perform peeling by applying a temperature change, an alignment substrate itself, or a method in which an alignment film on the alignment substrate is removed by dissolution. You can 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 has an acrylic or epoxy-based overcoat layer on one or both sides of the thin film for the purpose of protecting these optically important alignment-fixed discotic liquid crystal material thin films. 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 improving (viewing angle compensation) effect is exhibited for a display in which a TN liquid crystal cell is driven in a normally white mode, and a color / viewing angle compensation effect is exhibited for an OCB mode liquid crystal display. The thickness of the compensator of the present invention depends on the method and parameters of the target liquid crystal display and cannot be generally stated, but it is usually in the range of 0.1 μm or more and 40 μm or less, more preferably 0.2 μm or more and 20 μm or less. The range is as follows, particularly preferably in the range of 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, which is not preferable.

However, in order to bring out the performance of the compensator of the present invention to a higher level, it is preferable to consider the parameters of the compensator and the axial arrangement in more detail. In general, the optical parameters and physical property values that characterize the structure of the compensator include director angle, compensation layer thickness, apparent in-plane retardation, and 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 that does not form a hybrid alignment, for example, a compensator that forms a tilt alignment, 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 peculiar birefringence value (hereinafter also referred to as Δn) referred to herein is the refractive index (hereinafter, referred to as Δn) of the compensator obtained by the manufacturing method of the present invention in a very small region in a direction perpendicular to the director of the discotic liquid crystal. No.) and the refractive index in the direction parallel to the director (hereinafter also referred to as ne). By using an Abbe refractometer, such a refractive index can be obtained by utilizing the property of providing information in the vicinity of the interface even in a structure in which the refractive index continuously changes.

Further, the discotic liquid crystal material may be sandwiched between two substrates having the same interface to suppress the hybrid alignment form, and the measurement may be performed by measuring a sample in which the director is oriented in one direction. You can The absolute value of the product of the intrinsic birefringence value thus obtained and the absolute film thickness of the compensator is in the range of 20 nm or more and 1000 nm or less when compensating for a TN mode display.
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. The compensating plate obtained by the manufacturing method of the present invention may use a plurality of compensating plates alone or a plurality of compensating plates with an oriented substrate or a second substrate obtained by the manufacturing method. In that case, it is preferable that the absolute value of the product of the unique birefringence value and the absolute film thickness of each compensating plate is within these ranges. When compensating for OCB mode displays, the above values are usually 5
It is preferably 0 nm or more and 200 nm or less.

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 compensator plane, apparent birefringence occurs when observed from the direction perpendicular to the compensator plane. The direction obtained when the director is projected in the compensator plane is apparently the fast axis, and the direction in the plane perpendicular to it 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 of the compensator of the present invention is usually 5 nm to 500 for monochromatic light of 550 nm when compensating for a TN mode liquid crystal display.
nm range, more preferably 10 nm to 300 nm range, particularly preferably 15 nm to 150 nm range. 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 compensating plate is preferably within these ranges. Also O
When compensating for a CB mode display, the above values are preferably in the range of 10 nm to 800 nm.

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. (1) First, the compensating plate 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 whose orientation is fixed and the transmission axis of the polarizer make an angle of 45 degrees. (2) Next, the compensator 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. (3) Calculate the average tilt angle from the relationship between the tilt angle of the compensator and the transmittance.

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, the compensator having the hybrid orientation is not completely equivalent to the 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 incident light traveling along the optical axis of the sample (however, at the compensator interface Consider the refraction of light). 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 compensating plate in which the hybrid orientation is formed. The average tilt angle obtained in this way is usually 2 degrees to 6 degrees.
0 degree range, preferably 5 degree to 50 degree range,
More preferably, it is in the range of 10 degrees 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 director angle, the film thickness of the compensator, and the in-plane apparent retarder are used as optical parameters and physical properties that can describe the structure of the compensator having hybrid orientation obtained by the manufacturing method of the present invention. A description has been given of the foundation value and the average tilt angle. All of the above values are measurable and it is naturally desirable to be within the preferred range for each. However, depending on the form of the compensator, for example, with an alignment substrate, with a second substrate, or with an overcoat layer, it may be difficult to measure all. 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 the same method, in the manufacturing method of the present invention, in general, the angle of the director in the vicinity of the compensator interface and the average tilt angle are constant regardless of the film thickness. The retardation value is proportional to the film thickness.

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, the compensating plate obtained by the manufacturing method of the present invention plays a decisive role for the compensation, and only the compensating plate (compensating element) made of the conventional liquid crystal polymer is used in any combination. Even in this case, it is impossible to exhibit an excellent compensating effect like the compensating plate for a liquid crystal display element 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.

When the compensating plate obtained by the manufacturing method of the present invention has a hybrid orientation, the compensating plate does not have the upper and lower sides of the compensating plate because they have the hybrid orientation. There is a slight difference in the compensation effect depending on whether the cell is closer to the cell. Further, in the compensating plate, the angle formed by the director of the liquid crystal near the interface with the compensating plate plane is 60 degrees or more and 90 degrees or less on one of the upper surface and the lower surface of the compensating plate, and on the opposite surface of the surface. Is 0 ° or more and 50 ° or less, and either face may be closer to the liquid crystal cell, but a face having a large angle between the director and the compensator plane (the angle is 60 ° to 9 °).
It is preferable that the surface (0 degree) is close to the driving liquid crystal cell and far 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.
Examples of preparation of discotic liquid crystal materials and the analytical methods used in the examples are as follows. (Chemical structure determination) It was measured by 400 MHz ¹ H-NMR (JNM-GX400 manufactured by JEOL Ltd.). (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. (Method of quantifying distilling acetic acid) Acetic acid distilling from the reactor was aggregated by passing through a water cooling tube and collected in a receiver. The amount of increase in the weight of the receiver was defined as the deacetic acid distillation amount.

Preparation of Discotic Liquid Crystal Material (Preparation Example 1) Hexaacetoxytriphenylene 50 m
mol, 4-butoxybenzoic acid 100 mmol, 4-
A mixture of 100 mmol of hexyloxybenzoic acid and 100 mmol of 4-octyloxybenzoic acid was charged into a glass flask with a capacity of 300 ml provided with a mechanical stirrer and a distilling outlet equipped with a water cooling tube for distilling acetic acid, and under a nitrogen atmosphere. The mixture was reacted at 260 ° C. for 2 hours while stirring. The amount of acetic acid distilled at this point was 14.
It was 2 g (79% of theory). Then, the reaction was performed at 280 ° C. for 8 hours under a nitrogen stream of 50 ml / min to obtain a discotic liquid crystal material (Material 1). Material 1 had an isotropic transition temperature of 284 ° C.

(Preparation Example 2) Hexaacetoxytriphenylene 50 mmol, 4-tert-butylbenzoic acid
145 mmol, 4-heptyloxybenzoic acid 145
The mmol mixture was placed in a glass flask having a capacity of 300 ml, which was equipped with a mechanical stirrer and was the same as in Preparation Example 1, and reacted at 250 ° C. for 3 hours while stirring under a nitrogen atmosphere. The amount of acetic acid distilled at this point was 12.3 g (68% of theory). Then, the reaction was performed at 250 ° C. for 7 hours under a nitrogen stream of 50 ml / min to obtain a discotic liquid crystal material (material 2). Material 2 had an isotropic transition temperature of 265 ° C.

(Preparation Example 3) Hexaacetoxytriphenylene 50 mmol, 4-tert-butylbenzoic acid
A mixture of 112 mmol, stearic acid 112 mmol and sebacic acid 40 mmol was placed in a glass flask having a capacity of 500 ml equipped with a mechanical stirrer and an acetic acid distillation outlet, and stirred under a nitrogen atmosphere at 280.
The reaction was performed at 8 ° C. for 8 hours. At this point, the acetic acid distillate was 16.
It was 6 g (92% of theory). Then, the discotic liquid crystal material (material 3) was obtained by heating at 290 ° C. for 1 hour under a reduced pressure of 1 mmHg. Material 3 had an isotropic transition temperature of 278 ° C.

Preparation Example 4 Hexaacetoxytriphenylene 50 mmol, 4-tert-butylbenzoic acid
75 mmol, 4-pentylbenzoic acid 75 mmol,
A mixture of 75 mmol of 4-hexyloxybenzoic acid and 80 mmol of 4-heptyloxybenzoic acid was charged into a glass flask having a capacity of 300 ml equipped with a mechanical stirrer and reacted at 280 ° C. for 8 hours while stirring under a nitrogen atmosphere to cause a discotic liquid crystal. A material (material 4) was obtained. Material 4 had an isotropic transition temperature of 252 ° C.

Preparation Example 5 Hexaacetoxytriphenylene 50 mmol, 6-hexyloxy-2-naphthoic acid 150 mmol, 4-pentyloxybenzoic acid
A 150 mmol mixture was placed in a glass flask having a capacity of 300 ml equipped with a mechanical stirrer and an acetic acid distillation outlet, and reacted at 250 ° C. for 3 hours while stirring under a nitrogen atmosphere. The amount of acetic acid distilled at this point was 14.4 g.
(80% of the theoretical amount). Then, under a nitrogen stream, 25
The reaction was performed at 0 ° C. for 6 hours to obtain a discotic liquid crystal material (Material 5). Material 5 has an isotropic transition temperature of 2
It was 84 ° C.

Preparation Example 6 Hexaacetoxytriphenylene 50 mmol, 4-heptyloxybenzoic acid 2
A mixture of 80 mmol and 10 mmol of terephthalic acid was charged into a glass flask having a capacity of 300 ml equipped with a mechanical stirrer, and stirred under a nitrogen atmosphere while
A discotic liquid crystal material (material 6) was obtained by conducting a reaction at 260 ° C. for 2 hours and then at 280 ° C. for 6 hours. Material 6 had an isotropic transition temperature of 235 ° C.

Preparation Example 7 Hexaacetoxytriphenylene 5 mmol, 4'-heptyloxy [1,1'-
Biphenyl] -4-carboxylic acid 7 mmol, 4-hexyloxybenzoic acid 19 mmol, 4,4 ′-(ethane-1,2-diylbisoxy) bisbenzoic acid 2 mm
The ol mixture was charged into a 100 ml capacity glass flask equipped with a mechanical stirrer and an acetic acid distillation outlet,
The mixture was reacted at 250 ° C. for 3 hours while stirring under a nitrogen atmosphere. At this point, acetic acid was 1.5 g (theoretical amount of 83
%) Distilled. Then under a nitrogen stream of 20 ml / min,
The reaction was carried out at 250 ° C. for 6 hours to obtain a discotic liquid crystal material (Material 7). Material 7 had an isotropic transition temperature of 278 ° C.

Preparation Example 8 Hexaacetoxytriphenylene 50 mmol, 4-octyloxybenzoic acid 1
20 mmol, 6-pentyloxy-2-naphthoic acid
Using a 180 mmol mixture, a reaction was carried out in the same manner as in Preparation Example 5 to obtain a discotic liquid crystal material (Material 8). Material 8 had an isotropic transition temperature of 283 ° C.

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

Preparation Example 10 Hexaacetoxytriphenylene 50 mmol, 3-heptyloxybenzoic acid
200 mmol and 6-heptyloxy-2-naphthoic acid 100 mmol were charged into a glass container equipped with a mechanical stirrer and an acetic acid distillation outlet, and reacted at 245 ° C. for 2 hours while stirring under a nitrogen atmosphere. At this point, the amount of acetic acid distilled was 11.7 g (65% of theory). Then, the reaction was carried out at 245 ° C. for 8 hours under a nitrogen stream of 50 ml / min to prepare a discotic liquid crystal material (material 10).
I got Material 10 has an isotropic transition temperature of 258
° C.

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

Preparation Example 12 Hexaacetoxytriphenylene (500 mmol), 6-hexyloxy-2-naphthoic acid (480 mmol), 4-octyloxybenzoic acid (2485 mmol), and terephthalic acid (20 mmol) were added to a mechanical stirrer and an acetic acid distillation outlet in an internal volume of 5 liters. It was charged in a stainless steel (SUS316) autoclave and stirred under a nitrogen atmosphere while stirring 260
The reaction was carried out at 3 ° C. for 3 hours. The amount of acetic acid distilled at this point is 1
It was 48 ml (82% of theory). Then 300m
A discotic liquid crystal material (material 12) was obtained by reacting at 260 ° C. for 10 hours in a nitrogen stream of 1 / min. Material 12
Has an isotropic transition temperature of 273 ° C.

(Proof that discotic liquid crystal is used) The discotic liquid crystal material is
As a result of observation under a polarizing microscope, Mol. Cryst. Li
q. Cryst. , 106 , 121-146, 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. Preparation Example 1
All the liquid crystal materials obtained in Example 12 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 wt% 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. 4 was simulated by a computer, and the result was that the average tilt angle was 52 degrees. 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 shown in FIG. 5 are obtained, the discotic liquid crystal has a hybrid orientation, and the average tilt angle is 23.
Degree. Next, using two sheets of the laminate 2, the TN cell (90
The effect of improving the viewing angle with respect to the degree of twist and the retardation of 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. 6 to measure the contrast. As a result, as shown in FIG. 7, 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 compared to 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. The compensator 3 exhibited a good effect of improving the viewing angle with respect to the TN cell, as in Examples 1 and 2.

Example 4 Material 4 (8 g) was dissolved in 92 g of chloroform to prepare an 8 wt% solution, which was applied on 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 and heat-treated in an oven at 250 ° C. for 15 minutes, it was 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. The compensator 4 exhibited a good effect of improving the viewing angle with respect to the TN cell as in Examples 1 and 2.

(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. The compensator 5 exhibited a good effect of improving the viewing angle with respect to the TN cell as in Examples 1 and 2.

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. The compensating plate 6 is the same as in the first and second embodiments.
A good viewing angle improving effect was exhibited for the TN 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. The compensating plate 7 exhibited a good viewing angle improving effect on the TN cell, as in Examples 1 and 2.

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. The compensator 8 exhibited a good effect of improving the viewing angle with respect to the TN cell as in Examples 1 and 2.

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. The compensating plate 9 has the same T as in the first and second embodiments.
A good viewing angle improving effect was exhibited for the N 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. The compensating plate 10 exhibited a good effect of improving the viewing angle with respect to the TN cell as in Examples 1 and 2.

(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.
The compensator 11 exhibited a good effect of improving the viewing angle with respect to the TN cell as in Examples 1 and 2.

(Example 12) 1 material 12 (140 g) was added.
It was dissolved in 860 g of chloroform to prepare a 7% by weight solution. Next, the material 12 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 60 ° C.
After drying, heat-treat at 218 ° C for 15 minutes in the oven,
It was taken out at room temperature and cooled to obtain a compensating plate 12. The thickness of the compensator 12 was 3.1 μm. Further, the birefringence was 0.10 as measured by the refractive index, and the product of this and the film thickness was 31.
It became 0 nm. Further, when polarization analysis was performed using an ellipsometer, the apparent retardation on the front side was 103 nm. Fast axis is 3 with rubbing direction
There was an in-plane direction of the film deviated. Also, as in Example 1, the apparent retardation value was measured while tilting along the rubbing direction, and the average tilt angle was 34 degrees. The compensating plate 12 has the same TN as in the first and second embodiments.
A good viewing angle improving effect was exhibited for the cell.

[0101]

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

Front page continuation (72) Inventor Yoshihiro Kobori 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Nippon Petroleum Co., Ltd. Central Technology Research Institute

Claims (4)

[Claims] 1. Obtained by performing a deacetic acid reaction between at least one planar condensed ring compound having at least 6 phenolic acetate groups in one molecule and a plurality of carboxylic acid compounds having at least 6 carbon atoms. A method for producing a compensator for a liquid crystal display device, which comprises applying a discotic liquid crystal material substantially composed of the obtained reaction product onto an alignment substrate, followed by heat treatment and cooling. 2. A discotic liquid crystal material comprising at least one phenolic acetate group having 6 or more phenolic acetate groups per molecule in a reactor provided with an acetic acid distillation outlet for distilling acetic acid by-produced. A planar fused ring compound and a plurality of carboxylic acid compounds having 6 or more carbon atoms are provided to promote the deacetic acid reaction while distilling acetic acid from the acetic acid distillation outlet,
Reaction obtained by carrying out the reaction under reduced pressure or an inert gas stream from the time of acetic acid distillation at which the amount of acetic acid distilled from the acetic acid distillation outlet corresponds to 30 to 95 mass% of the theoretical amount of acetic acid distillation. The method for producing a compensating plate for a liquid crystal display device according to claim 1, which is substantially composed of a product. 3. A planar condensed ring compound having 6 or more phenolic acetate groups in one molecule is 2, 3, 6,
7. The method for producing a compensator for a liquid crystal display device according to claim 1, wherein the compensator is 7,10,11-hexaacetoxytriphenylene. 4. A plurality of carboxylic acid compounds having 6 or more carbon atoms are selected from 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 plurality of kinds.