JPH0642031B2 - Composition for liquid crystal alignment film - Google Patents

Description

The present invention relates to a composition for liquid crystal alignment film.

(Prior art) super twisted birefringence ef
fect) (TJscheffer and J.Nehring, Appl.phys.Leff.
SB using 45 (10), 1021 (1984))
The E type liquid crystal display device has extremely excellent contrast and visual characteristics as compared with the conventional TN type liquid crystal display device.

As the orientation control film used for this purpose, an inorganic oblique vapor deposition film of silicon oxide or the like has been mainly used because it is necessary to increase the pretilt angle.

(Problems to be Solved by the Invention) However, the inorganic orthorhombic vapor-deposited film has selectivity for liquid crystals, and it is difficult to favorably orient all liquid crystal compositions.

In addition, there is a drawback that the high temperature heating at the time of assembly causes unevenness in the alignment, which lowers the yield and deteriorates the productivity, and the contrast and visual characteristics required for the alignment control film cannot be satisfied.

The present invention provides a composition for liquid crystal alignment film, which eliminates this drawback.

(Means for Solving the Problems) The present invention is obtained by reacting at least one of a carboxylic acid anhydride, a diamine and a diaminomonoamide as a component having a fluorine atom with a carboxylic acid anhydride, a diamine and a diaminomonoamide. The present invention relates to a composition for a liquid crystal alignment film containing a polyamic acid.

The polyamic acid used in the present invention is synthesized by stirring reaction of carboxylic acid anhydride, diamine and diaminomonoamide. These reactions are performed under anhydrous conditions, preferably 50
It is carried out at a temperature of ° C or lower.

Regarding the reaction ratio of the carboxylic acid anhydride, the diamine and the diaminomonoamide, it is preferable that the number of moles of the carboxylic acid anhydride and the number of moles of the diamine and diaminomonoamide are equimolar. The diaminomonoamide is preferably used in the range of 0.1 to 50 mol% based on the total amount of the diamine and diaminomonoamide. This reaction is carried out in the presence of a solvent such as dimethylacetamide, dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone.

In the present invention, carboxylic acid anhydride, diamine and diaminomonoamide are reacted with at least one of carboxylic acid anhydride and diamine as a component having a fluorine atom.

As the carboxylic acid anhydride having a fluorine atom, for example,
2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, bis (3,
4-dicarboxyphenyl) hexafluoropropane,
4,4′-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane, (trifluoromethyl) pyromellitic acid, bis (trifluoromethyl) pyromellitic acid, 5,5′-bis ( Trifluoromethyl) -3,3 ',
4,4'-tetracarboxybiphenyl, 2,2 ', 5,5'-tetrakis (trifluoromethyl) -3,3', 4,4'-tetracarboxybiphenyl, 5,5'-bis (tri Fluoromethyl) -3,3 ', 4,4'-tetracarboxydiphenyl ether, 5,5'-bis (trifluoromethyl) -3,
3 ', 4,4'-tetracarboxybenzophenone, bis [(trifluoromethyl) dicarboxyphenoxy] benzene, bis [(trifluoromethyl) dicarboxyphenoxy] biphenyl, bis [(trifluoromethyl) )
Dicarboxyphenoxy] (trifluoromethyl) benzene, bis [(trifluoromethyl) dicarboxyphenoxy] bis (trifluoromethyl) biphenyl, bis [(trifluoromethyl) dicarboxyphenoxy] diphenyl ether , Bis (dicarboxyphenoxy)
(Trifluoromethyl) benzene, bis (dicarboxyphenoxy) bis (trifluoromethyl) benzene, bis (dicarboxyphenoxy) tetrakis (trifluoromethyl) benzene, bis (dicarboxyphenoxy)
Bis (trifluoromethyl) biphenyl, bis (dicarboxyphenoxy) tetrakis (trifluoromethyl)
Bisphenyl, 2,2-bis [4- (2,3-dicarboxybenzoyloxy) phenyl] hexafluoropropane,
2,2-bis [4- (3,4-dicarboxybenzoyloxy) -3-bromophenyl] hexafluoropropane,
2,2-Bis [4- (3,4-dicarboxybenzoyloxy) -3,5-dibromophenyl] hexafluoropropane, 2,2-bis [4- (3,4-dicarboxybenzoyloxy)- 3,5-Dimethylphenyl] hexafluoropropane, 2,2-bis [4- (3,4-dicarboxybenzoyloxy) phenyl] octafluorobutane, 2,2-bis [4- (2-trifluoromethyl) -3,4-Dicarboxybenzoyloxy) phenyl] hexafluoropropane, 1,3-bis [4- (3,4-dicarboxybenzoyloxy) phenyl] hexafluoropropane, 1,5-bis [4- (3 , 4-Dicarboxybenzoyloxy) phenyl] decafluoropentane, 1,6-bis [4- (3,4-dicarboxybenzoyloxy) phenyl] dodecafluorohexane, 1,7-bis [4- (3,4 -Dicarbox Benzoyloxy) phenyl] tetradecafluoroheptane, 1,5-bis [4- (3,4-dicarboxybenzoyloxy) -3,5-dibromophenyl] decafluoropentane, 1,5-bis [4- ( 3,4-Dicarboxybenzoyloxy) -3,5-bistrifluoromethylphenyl] decafluoropentane, 1,5-bis [4- (2-trifluoromethyl-3,5-dicarboxybenzoyloxy) phenyl] Decalfluoropentane, 2,2-bis [4- (3,4
-Dicarboxyphenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (3,4 -Dicarboxyphenyloxy) -3-bromophenyl] hexafluoropropane, 2,2-bis [4
-(3,4-Dicarboxyphenoxy) -3,5-dibromophenyl] hexafluoropropane, 2,2-bis [4-
(3,4-Dicarboxyphenoxy) -3,5-dimethylphenyl] hexafluoropropane, 2,2-bis [4- (3,4
-Dicarboxyphenyloxy) phenyl] octafluorobutane, 2,2-bis [4- (3,4-dicarboxy-2-
Trifluoromethylphenoxy) phenyl] hexafluoropropane, 1,3-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane, 1,5-
Bis [4- (3,4-dicarboxyphenoxy) phenyl] decafluoropentane, 1,6-bis [4- (3,4-dicarboxyphenoxy) phenyl] dodecafluorohexane, 1,7- Bis [4- (3,4-dicarboxyphenoxy) phenyl] tetradecafluoropentane, 1,5-bis [4- (3,4-dicarboxyphenoxy) -3,5-dibromophenyl] Decafluoropentane, 1,5-bis [4
-(3,4-Dicarboxyphenoxy) -3,5-bistrifluoromethylphenyl] decafluoropentane, 1,5-
Bis (4- (3,4-dicarboxy-2-trifluoromethylphenoxy) phenyl] decafluoropentane and the like are used.

Further, as the diamine having a fluorine atom, for example, 2,
2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 2,2
-Bis [4- (2-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (2-aminophenoxy) -3,5-dimethylphenyl] hexafluoropropane, p-bis (4-amino- 2-trifluoromethylphenoxy) benzene, 4,4′-bis (4-amino-2-trifluoromethylphenoxy) biphenyl, 4,
4'-bis (4-amino-3-trifluoromethylphenoxy) biphenyl, 4,4'-bis (4-amino-2-
Trifluoromethylphenoxy) diphenyl sulfone,
4,4'-bis (3-amino-5-trifluoromethylphenoxy) diphenyl sulfone, 2,2-bis [4- (4
-Amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, etc. are used. Examples of the diaminomonoamide having a fluorine atom include 2,2
-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane-3-carbonamide and the like are used.

As the diaminomonoamide, for example, 1,4-diaminobenzene-2-carbonamide, 4,4'-diaminodiphenyl ether-3-carbonamide and the like are used.

Examples of the carboxylic acid anhydride include pyromellitic acid anhydride, 2,3,6,7-naphthalenetetracarboxylic acid anhydride, 3,
3 ', 4,4'-diphenyltetracarboxylic anhydride, 1,2,
5,6-naphthalenetetracarboxylic anhydride, 2,2 ', 3,3'
-Diphenyl tetracarboxylic acid anhydride, thiophene-2,
3,4,5-Tetracarboxylic acid anhydride, 2,2-bis (3,4-biscarboxyphenyl) propane anhydride, 3,4-dicarboxyphenylsulfone anhydride, perylene-3,4,9 , 10
-Tetracarboxylic acid anhydride, bis (3,4-dicarboxyphenyl) ether anhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic acid anhydride and the like are used.

Examples of diamines include m-phenylenediamine, p-phenylenediamine, m-xylene diamine,
p-xylylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,
5'-tetramethyl-4,4'-diaminodiphenylmethane, 2,2'-bis (4-aminophenyl) propane, 4,
4'-methylene dianiline, benzidine, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 1,5-diaminonaphthalene, 3,3'-dimethylbenzidine, 3,3 ' -Dimethoxybenzidine or the like is used.

Carboxylic acid anhydride having fluorine, carboxylic acid anhydride,
Two or more kinds of diamine having fluorine, diaminomonoamide having diamine fluorine and diaminomonoamide may be used in combination.

In addition, in order to improve the adhesion to glass substrates, metals, etc. (Wherein R is a divalent hydrocarbon group, R ₁ , R ₂ , R ₃ and R ₄ are monovalent hydrocarbon groups, and n is an integer of 1 or more). But it doesn't matter.

The above-mentioned polyamic acid is applied to the liquid crystal holding substrate and the electrode by coating the polyamic acid with dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methyl-
A 0.01-40% by weight solution of 2-pyrrolidone or the like is applied onto the substrate and the electrode by a dip method, a spinner method, a spray method, a printing method, a brush coating method or the like.

After coating 100 ° C to 400 ° C, preferably 250 ° C to 350
The polyamic acid is dehydrated and cyclized by heat treatment at ℃ to obtain a polyimide isoindoloquinazolinedione polymer film. The polymer film is rubbed to form a liquid crystal alignment film. The tilt angle between the liquid crystal alignment film and the liquid crystal was 2-3 ° in the conventional polymer polyimide film, but when the composition according to the present invention was used as the liquid crystal alignment film, the tilt angle was up to about 20 °. The composition for liquid crystal alignment film containing a polyamic acid according to the present invention is particularly suitable for an SBE type liquid crystal display device.

(Example) An example will be described.

In the embodiment, the tilt angle is measured by the journal of
Applied Physics (Jpn.J.Appl.Phys.), Vol. 19, 2013 (1980).

Example 1 In N-methyl-2-pyrrolidone 2,2-bis [4-
(4-Aminophenoxy) phenyl] hexafluoropropane 0.9 mol, 4,4'-diaminodiphenyl ether-
0.1 mol of 3-carbonamide and 2,2-bis [4- (3,4
1.0 mol of dicarboxyphenoxy) phenyl] hexafluoropropane dianhydride at 25 ° C. for 5 hours and then 80
A 5 wt% N-methyl-2-pyrrolidone solution of polyamic acid, which is a precursor of a polyimide isoindoloquinazolinedione-based polymer obtained by condensation at 5 ° C for 5 hours, was spinner-coated to form an indium oxide electrode. It was applied to a glass substrate (3 cm × 3 cm, thickness 2 mm). After application, 250
The mixture was heated at 1 ° C. for 1 hour for dehydration ring closure to form a polyimide isoindoloquinazolinedione-based polymer coating with a thickness of 600 to 800 Å.

Then, a liquid crystal (ZLI-2293 (manufactured by Merck), a right-handed chiral agent CB15 (manufactured by BDH) was used for ZL using a pair of substrates whose coating was rubbed in a certain direction with gauze.
3.07% by weight to I-2293 and a left-handed chiral agent S811 (Merck) against ZLI-2293
Liquid crystal display (thickness approx. 3.33% by weight) is enclosed.
6.3 μm) was prepared. The tilt angle was measured and found to be 4.9 °.

When a voltage was applied to this device and the rising characteristics and contrast were observed, it was extremely good.

Example 2 2,2-bis [4-in N-methyl-2-pyrrolidone
(4-Aminophenoxy) phenyl] hexafluoropropane 0.8 mol, 4,4'-diaminodiphenyl ether-
5% by weight of polyamic acid obtained by condensing 0.2 mol of 3-carbonamide and 1.0 mol of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride at 25 ° C for 6 hours and then at 80 ° C for 6 hours. A liquid crystal display device having the same characteristics as in Example 1 was obtained by using the N-methyl-2-pyrrolidone solution of. The tilt angle was measured and found to be 53 °.

(Effect of the Invention) By using the composition for liquid crystal alignment film according to the present invention in the alignment control film, a liquid crystal display device having excellent contrast and visual characteristics can be obtained without lowering the yield.

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Claims (1)

[Claims] 1. A liquid crystal containing a polyamic acid obtained by reacting a carboxylic acid anhydride, a diamine and a diaminomonoamide with at least one of a carboxylic acid anhydride, a diamine and a diaminomonoamide as a component having a fluorine atom. Composition for alignment film.