JP3322090B2 - Imide compound and liquid crystal aligning agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel imide compound and a liquid crystal aligning agent containing the imide compound together with a polyimide.

[0002]

2. Description of the Related Art At present, as a liquid crystal display device, a liquid crystal alignment film made of polyimide or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a substrate for the liquid crystal display device.
The two sheets are arranged opposite to each other and a nematic liquid crystal layer having a positive dielectric anisotropy is formed in the gap to form a cell having a sandwich structure. The major axis of the liquid crystal molecules is transferred from one substrate to the other substrate. It was made to twist continuously 90 degrees toward
2. Description of the Related Art A TN type liquid crystal display device having a so-called TN (Twisted Nematic) liquid crystal cell is known. In recent years, STN (S) has a higher contrast than a TN type liquid crystal display element and has less viewing angle dependence.
An upper Twisted Nematic type liquid crystal display device has been developed. This STN type liquid crystal display element uses a nematic type liquid crystal blended with a chiral agent as an optically active substance as a liquid crystal, and the major axis of the liquid crystal molecule is continuously twisted over 180 degrees between substrates. This makes use of the birefringence effect generated by this. The liquid crystal alignment in these TN type liquid crystal display elements and STN type liquid crystal display elements is expressed by a liquid crystal alignment film formed on the substrate surface. As a method of forming the liquid crystal alignment film, a liquid crystal alignment agent containing polyimide or the like is applied to the surface of the substrate by a printing method or the like,
There is a method in which the film is dried to form a coating film as an alignment film material, and the coating film is subjected to a rubbing treatment to impart an alignment ability of liquid crystal molecules.

However, in order to improve the display characteristics and electrical characteristics of the liquid crystal display element, it is necessary that the thickness of the liquid crystal alignment film is uniform, specifically, the variation of the film thickness is ± 50 °. It is preferably within the range.

[0004]

However, when a conventionally known liquid crystal aligning agent is applied by a printing method or the like, the coating film to be formed has a thickness variation of more than 50 °, and therefore, a uniform thickness of the coating film occurs. There is a problem that a good liquid crystal alignment film having excellent properties cannot be obtained. The present invention has been made to solve such a problem.

An object of the present invention is to provide a novel imide compound which is useful as a component of a liquid crystal aligning agent. Another object of the present invention is to provide a liquid crystal aligning agent having good application characteristics, which can exhibit good alignment characteristics and can form a liquid crystal alignment film having excellent uniformity of film thickness. It is in.

[0006]

Means for Solving the Problems The novel imide compound of the present invention has a structure represented by the following general formula (1).
Has a logarithmic viscosity (ηln) of 0.05 to 1 dl / g.
Characterized in that that.

[0007]

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Further, the liquid crystal aligning agent of the present invention comprises the above-mentioned imide compound [hereinafter also referred to as “imide compound (A)”. )
And a polyimide having a repeating unit represented by the following general formula (2) [hereinafter, also referred to as “polyimide (B)”. )
And is characterized by containing.

[0009]

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[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. <Imide compound (A)> The imide compound (A) of the present invention
And (i) a tetracarboxylic dianhydride represented by the following general formula (3) (hereinafter referred to as “specific tetracarboxylic dianhydride”) and a diamine compound represented by the following general formula (4) To obtain an amic acid compound, and the amic acid compound is synthesized by dehydration and ring closure, or (ii) the above-mentioned specific tetracarboxylic dianhydride and a diisocyanate represented by the following general formula (5) It is synthesized by condensing with a compound.

[0011]

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Wherein R ¹ and R ² are the same organic groups as R ¹ and R ² in the general formula (1), respectively. ]

Specific examples of the specific tetracarboxylic dianhydride represented by the general formula (3) include 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,2,3
4-cyclobutanetetracarboxylic dianhydride, 1-methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Product, 1,3-dimethyl-
1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,4-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3-trimethyl-
1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-ethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-diethyl-1,2,3
4-cyclobutanetetracarboxylic dianhydride, 1,3-
Diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,4-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3-triethyl-1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1-propyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dipropyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,3-dipropyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,4-dipropyl-
1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3-tripropyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-butyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,2-dibutyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dibutyl-1,2,2
3,4-cyclobutanetetracarboxylic dianhydride, 1,
4-dibutyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3-tributyl-1,2,2
3,4-cyclobutanetetracarboxylic dianhydride, 1-
Phenyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-diphenyl-1,2,3,4-
Cyclobutanetetracarboxylic dianhydride, 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,4-diphenyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,2,3-triphenyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5- Dioxo-3-
Furanyl) -naphtho [1,2-c] -furan-1,3-
Dione, 5- (2,5-dioxotetrahydrofural)
And -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride.

Specific examples of the diamine compound represented by the general formula (4) used in the synthesis of the above (i) include:
For example, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-
Diaminodiphenylethane, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylether, 1,5-
Diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 3,4'-diaminodiphenyl ether, 3,3 '
-Diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2
-Bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-
Aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene,
1,3-bis (4-aminophenoxy) benzene, 1,
3-bis (3-aminophenoxy) benzene, 9,9-
Bis (4-aminophenyl) -10-hydroanthracene, 9,9-bis (4-aminophenyl) fluorene,
4,4′-methylene-bis (2-chloroaniline),
2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy- Aromatic diamines such as 4,4'-diaminobiphenyl; aromatic diamines having a hetero atom such as diaminotetraphenylthiophene; 1,1-methaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine , Hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7 -Methanoindaniline methylenediamine Tricyclo [6,2,
^1,02.7 ] -aliphatic and alicyclic diamines such as undecylenedimethyldiamine; the following chemical formulas (1) to (3)
And the like, and these can be used alone or in combination of two or more.

[0015]

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Of these, p-phenylenediamine,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2 -Screw [4
-(4-Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane and the like are preferable.

The synthesis reaction (i) is carried out in an organic solvent at a temperature of usually 0 to 150 ° C, preferably 60 to 100 ° C. Here, the organic solvent is not particularly limited as long as it can dissolve the amic acid compound to be synthesized. For example, N-methyl-2-pyrrolidone,
Non-protonic polar solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; m-cresol, xylenol, phenol, halogenated phenol, etc. Can be exemplified. Of these, N-methyl-2-pyrrolidone and γ-butyrolactone are preferred. In addition, the amount (a) of the organic solvent used is usually such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to the total amount (a + b) of the reaction solution.
Preferably, the amount is from 1 to 10% by weight.

An amic acid compound that produces alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc., which are poor solvents for the amic acid compound, is deposited on the organic solvent. It can be used together within the range not to do. Specific examples of such a poor solvent include:
For example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate,
Ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol i-propyl ether, ethylene glycol
n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate,
Diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene,
Examples include toluene and xylene.

In the above synthesis reaction (i), the method of adjusting the number of repeating units (m) of the amic acid compound to a range of 1 to 3 includes a method of synthesizing the amic acid compound as a terminal-modified compound and a method of synthesizing a tetramic compound. A method of performing a synthesis reaction by adjusting the use ratio of the carboxylic dianhydride and the diamine compound.

The terminal-modified amic acid compound can be obtained by adding an acid-anhydride or a monoamine compound to the reaction system during the synthesis. Here, examples of the acid-anhydride include maleic anhydride, phthalic anhydride, and nadic anhydride, and examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, and n-pentylamine. -Hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine , N-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine and the like.

The acid-anhydride and the monoamine compound are used in a ratio of 0.1 mol of the acid-anhydride to 1 mol of the diamine compound.
The ratio is 5 to 1 mol, or 0.5 to 1 mol of the monoamine compound per 1 mol of the tetracarboxylic dianhydride.

As a method of performing the synthesis reaction by adjusting the use ratio of the tetracarboxylic dianhydride and the diamine compound, an acid anhydride group contained in the tetracarboxylic dianhydride may be used.
The ratio of amino groups contained in the diamine compound is 1 equivalent /
The number of repeating units (m) of the amic acid compound obtained by performing a synthesis reaction at a ratio of 1000 equivalents to 2 equivalents / 3 equivalents, or 3 equivalents / 2 equivalents to 1000 equivalents / 1 equivalent is in the range of 1 to 3. Can be adjusted.

As described above, a solution of the amic acid compound is obtained. Then, the solution is poured into a large amount of a poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain an amic acid compound. Further, the step of dissolving the amic acid compound in the organic solvent again and then performing the step of precipitating with the poor solvent once or several times,
The amic acid compound can be purified.

The amic acid compound obtained as described above has a logarithmic viscosity (ηln) value of usually 0.05 to 5
dl / g, preferably 0.05 to 1 dl / g. The value of the logarithmic viscosity (ηln) in the present invention is N-methyl-
Using 2-pyrrolidone as a solvent, the concentration is 0.5 g / 1.
The viscosity is measured at 30 ° C. for a solution having a volume of 00 ml, and is determined by the following equation.

[0025]

(Equation 1)

The above amic acid compound is subjected to a dehydration ring closure (imidation reaction) to obtain the imide compound (A) of the present invention, for example, by heating the amic acid compound or by dehydrating the amic acid compound in a solution. A method of adding an agent and an imidation catalyst and heating as necessary.

The reaction temperature in the method of heating the amic acid compound is usually from 60 to 200 ° C., preferably from 1 to 200 ° C.
00 to 150 ° C. When the reaction temperature is lower than 60 ° C., the imidization reaction does not sufficiently proceed, and when the reaction temperature is higher than 200 ° C., the resulting imide compound may be colored intensely.

On the other hand, in the method of adding a dehydrating agent and an imidation catalyst to a solution of an amic acid compound, the dehydrating agent may be an acid anhydride such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride. it can. The amount of the dehydrating agent used is preferably 1.6 to 20 mol per 1 mol of the repeating unit of the amic acid compound. Further, as the imidation catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but are not limited thereto. The amount of the imidization catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the dehydration ring closure, the organic solvents exemplified as those used for the synthesis of the amic acid compound can be exemplified. The reaction temperature of the dehydration ring closure is usually 0 to 1
80 ° C., preferably 60 to 150 ° C. The imide compound of the present invention can be purified by subjecting the reaction solution thus obtained to the same operation as the method for purifying the amic acid compound.

Specific examples of the diisocyanate compound represented by the general formula (5) used in the reaction (ii) include an aliphatic diisocyanate compound such as hexamethylene diisocyanate; a cycloaliphatic diisocyanate compound such as cyclohexane diisocyanate; Diphenylmethane-4,4'-diisocyanate, diphenylether-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate, 1,2-diphenylethane-p, p'- Diisocyanate, 2,2
-Diphenylpropane-p, p'-diisocyanate,
2,2-diphenyl-1,1,1,3,3,3-hexafluoropropane-p, p'-diisocyanate, 2,
2-diphenylbutane-p, p'-diisocyanate,
Diphenyl dichloromethane-4,4'-diisocyanate, diphenylfluoromethane-4,4'-diisocyanate, benzophenone-4,4 'diisocyanate,
Aromatic diisocyanate compounds such as N-phenylbenzoic acid amide-4,4′-diisocyanate can be mentioned, and these can be used alone or in combination of two or more. A catalyst is not particularly required for the reaction (ii), and the reaction temperature is usually 50 to 200 ° C, preferably 100 to 160 ° C.

In the above-mentioned synthesis reaction (ii), the number of repeating units (m) of the imide compound is adjusted in the range of 1 to 3 by using the number of repeating units of the amic acid compound in the above-mentioned synthesis reaction (i). According to the adjustment method,
Examples include a method of synthesizing a terminal-modified imide compound by adding an anhydride or a monoisocyanate compound to a reaction system, and a method of performing a synthesis reaction by adjusting the use ratio of a tetracarboxylic dianhydride and a diisocyanate compound. Can be

The imide compound obtained by the above reactions (i) and (ii) has a logarithmic viscosity (ηln) value.
Usually, it is 0.05 to 1 dl / g.

The imide compound (A) of the present invention is extremely useful as a component of a liquid crystal aligning agent. The liquid crystal aligning agent containing the imide compound (A) is evident from the results of Examples described later. As described above, the coating characteristics are remarkably superior to those using only polyimide as an active ingredient, and a liquid crystal alignment film having excellent uniformity in film thickness can be formed only by the liquid crystal alignment agent.

<Polyimide (B)> Imide compound (A)
The polyimide (B) constituting the liquid crystal aligning agent of the present invention when contained together with (iii) a tetracarboxylic dianhydride represented by the following general formula (6) and a polyimide (B) represented by the following general formula (7) A polyamic acid is obtained by reacting with a diamine compound and synthesized by dehydrating and cyclizing the polyamic acid, or (iv) a tetracarboxylic dianhydride represented by the following general formula (6), and It is synthesized by a condensation reaction with a diisocyanate compound represented by the general formula (8).

[0034]

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Wherein R ⁹ and R ¹⁰ are the same organic groups as R ⁹ and R ¹⁰ in the general formula (2), respectively. ]

Specific examples of the tetracarboxylic dianhydride represented by the general formula (6) include, for example, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,2,2
3,4-cyclobutanetetracarboxylic dianhydride, 1,
2,3,4-butanetetracarboxylic dianhydride, 1,
2,3,4-cyclopentanetetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-
1,2-dicarboxylic dianhydride, bicyclo [2,2,
2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and other aliphatic and cycloaliphatic tetracarboxylic dianhydrides; pyromellitic dianhydride, 3,3 ′,
4,4′-benzophenonetetracarboxylic dianhydride,
3,3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride 3,3 ′, 4,4′-biphenylethertetracarboxylic dianhydride, 3,3 ′, 4,4 ′
-Dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4 '-Bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,
4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride,
3,3 ', 4,4'-perfluoroisopropylidenetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride , P-phenylene-
Bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) ) -4,4'-
Diphenylmethane dianhydride, 1,3,3a, 4,5,9
Examples include aromatic tetracarboxylic dianhydrides such as b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione. These can be used alone or in combination of two or more.

Specific examples of the diamine compound represented by the general formula (7) used in the reaction (iii) include the diamine compound represented by the general formula (4).

The ratio of the tetracarboxylic dianhydride and the diamine compound used in the synthesis reaction of the polyamic acid is as follows:
The acid anhydride group of the tetracarboxylic dianhydride is 0.7 to 1.4 with respect to 1 equivalent of the amino group contained in the diamine compound.
The equivalent ratio is preferable, and more preferably 0.8 to
This is a ratio of 1.2 equivalents.

The synthesis reaction of the polyamic acid in the above (iii) is usually carried out in an organic solvent at a temperature of 0 to 150 ° C., preferably 60 to 100 ° C. Here, examples of the organic solvent include those exemplified as those usable in the synthesis reaction of the amic acid compound. In addition, the amount (a) of the organic solvent used is usually such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to the total amount (a + b) of the reaction solution.
Preferably, the amount is from 1 to 30% by weight.

As described above, a polyamic acid solution is obtained. Then, this solution is poured into a large amount of a poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a polyamic acid. Further, the polyamic acid can be purified by dissolving the polyamic acid in an organic solvent again and then performing the step of precipitating with a poor solvent once or several times.

The polyamic acid obtained as described above has a logarithmic viscosity (ηln) of usually from 0.05 to 10%.
dl / g, preferably 0.05 to 5 dl / g.

The method of obtaining the polyimide (B) by dehydrating and ring-closing the polyamic acid is in accordance with the method of obtaining the imide compound (A) by dehydrating and ring-closing the amic acid compound of (i). Further, specific examples of the diisocyanate compound represented by the general formula (8) used in the method (iv) include a diisocyanate compound represented by the general formula (5). The reaction conditions in the method (iv) are the same as those in the method (ii) for obtaining the imide compound (A).

The polyimide obtained by the above reactions (iii) and (iv) has a logarithmic viscosity (ηln) value of usually 0.05 to 10 dl / g, preferably 0.05 to 5 d / g.
1 / g.

<Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention comprises an imide compound (A) and a polyimide (B) dissolved in an organic solvent. Here, the ratio of the imide compound (A) in the imide compound (A) and the polyimide (B) is usually 10 to 70% by weight,
Preferably, it is 10 to 40% by weight. This ratio is 10
When the amount is less than 10% by weight, the effect of improving the coating properties cannot be sufficiently exhibited, and a liquid crystal alignment film having excellent uniformity in film thickness may not be formed. On the other hand, this ratio is 70
If the amount exceeds 10% by weight, the viscosity of the liquid crystal aligning agent may be too low, and a reproducible coating film thickness may not be obtained.

As the organic solvent constituting the liquid crystal aligning agent,
Examples of the solvent used for the synthesis reaction of the amic acid compound and the polyamic acid and the imidization reaction thereof can be given. In addition, the poor solvents exemplified as those which can be used in combination in synthesizing the amic acid compound and the polyamic acid can be appropriately selected and used in combination.

The concentration of the imide compound (A) and the polyimide (B) in the organic solvent solution in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably 3 to 10% by weight. Is done. If the concentration is less than 3% by weight, the film thickness of the formed coating film is too small to obtain a good liquid crystal alignment film. On the other hand, if the concentration exceeds 10% by weight, the film thickness of the coating film becomes excessively large and a good liquid crystal alignment film cannot be obtained. Characteristics are diminished.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound from the viewpoint of improving the adhesion of the coating film to the substrate surface. Such functional silane-containing compounds include, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl ) -3-Aminopropyltrimethoxysilane, N-
(2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3 -Aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxyisyl-1,4,7-triazadecane, 10-triethoxysilyl-1, 4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N
-Benzyl-3-aminopropyltrimethoxysilane,
N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxy Silane, N-bis (oxyethylene)
And -3-aminopropyltriethoxysilane.

<Liquid crystal display element> A liquid crystal display element obtained by using the liquid crystal aligning agent of the present invention can be produced, for example, by the following method.

(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate on which a patterned transparent conductive film is provided, for example, by a printing method or the like, and then the coated surface is heated. To form Here, as the substrate, a transparent substrate made of, for example, glass such as float glass and soda glass; plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, and polycarbonate can be used. As a transparent conductive film provided on one surface of the substrate,
NESA film made of tin oxide (SnO ₂ ) (US PPG
Registered trademark), indium oxide-tin oxide (In ₂ O ₃
-SnO ₂ ) can be used. For patterning these transparent conductive films, a photo-
An etching method or a method using a mask in advance is used.
In applying the liquid crystal alignment agent, to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, on one surface of the substrate and on the transparent conductive film, a functional silane-containing compound,
A functional titanium-containing compound or the like can be applied in advance. The heating temperature is 80 to 200 ° C., preferably 12 to 200 ° C.
0 to 200 ° C. The thickness of the formed coating film is usually 0.001 to 1 μm, preferably 0.005 to 1 μm.
0.5 μm.

(2) A rubbing treatment is performed in which the formed coating film surface is rubbed in a certain direction with a roll around which a cloth made of a fiber such as nylon, rayon or cotton is wound. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film.

Further, the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention is partially irradiated with ultraviolet rays as disclosed in, for example, JP-A-6-222366 and JP-A-6-281937. To change the pretilt angle by changing the pre-tilt angle.
No. 4, a resist film was partially formed on the surface of the liquid crystal alignment film that had been subjected to the rubbing treatment, and the resist film was removed after performing the rubbing treatment in a direction different from the previous rubbing treatment. By performing a process that changes the alignment ability of the liquid crystal alignment film, it is possible to improve the visibility characteristics of the liquid crystal display element.

(3) Two substrates on which a liquid crystal alignment film is formed as described above are prepared, and the two substrates are separated by a gap so that the rubbing directions of the respective liquid crystal alignment films are orthogonal or antiparallel. (Cell gap)
The peripheral portions of the two substrates are bonded to each other using a sealant, and liquid crystal is injected and filled into the substrate surface and a cell gap defined by the sealant, and the injection hole is sealed to form a liquid crystal cell. Then, a polarizing plate is provided on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. Thus, a liquid crystal display element is obtained.

Here, as the sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, a nematic liquid crystal is preferable. For example, a Schiff base liquid crystal, an azoxy liquid crystal,
Biphenyl-based liquid crystal, phenylcyclohexane-based liquid crystal, ester-based liquid crystal, terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal, cubane-based liquid crystal, and the like can be used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate, and chiral agents such as those sold under the trade names "C-15" and "CB-15" (manufactured by Merck & Co.) It can also be used by adding it. Further, p-decyloxybenzylidene-p
Ferroelectric liquid crystals such as -amino-2-methylbutylcinnamate can also be used.

The polarizing plate to be bonded to the outer surface of the liquid crystal cell is a polarizing plate in which a polarizing film called an H film absorbing iodine is sandwiched between cellulose acetate protective films while stretching and aligning polyvinyl alcohol. Alternatively, a polarizing plate composed of the H film itself can be used.

[0055]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In addition, the number of repeating units in the imide compound (A) and the polyimide (B) is a value obtained from a molecular weight in terms of styrene measured using GPC.
In the following Examples and Comparative Examples, the evaluation method for “uniformity of film thickness” and “alignment of liquid crystal” is as follows.
It is as follows.

[Uniformity of Film Thickness] A coating film made of a liquid crystal aligning agent is formed on a transparent conductive film provided on a glass substrate, and the thickness of the coating film is measured with a stylus type film thickness meter “Alpha Step”. (Available from Tencor Corp. in the United States) to measure over 20 locations to determine the average value and the variation (standard deviation) of the film thickness.

[Orientation of Liquid Crystal] The presence or absence of an abnormal domain in the liquid crystal cell when the voltage was turned on / off was observed with a polarizing microscope, and the case where there was no abnormal domain was judged as “good”.

(Synthesis Example 1) 13.39 g (59.75 mmol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (specific tetracarboxylic dianhydride) and 4,4
4'-diaminodiphenylmethane (diamine compound)
7.90 g (39.83 mmol) and aniline 3.71
g (39.83 mmol) was dissolved in 225 g of N-methyl-2-pyrrolidone and reacted at room temperature for 20 minutes.
An amic acid compound solution was obtained. Next, 250 g of N-methyl-2-pyrrolidone, 9.36 g of pyridine and 12.08 g of acetic anhydride were added to the reaction solution, and 120 g of acetic anhydride was added.
The ring was dehydrated at 3 ° C. for 3 hours. Thereafter, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product,
The reaction product is separated by filtration and dried at 40 ° C. for 24 hours to obtain an imide compound of the present invention having an logarithmic viscosity of 0.10 dl / g [this is referred to as “imide compound (A-1)”. 15.41 g was obtained. This imide compound (A-
The value of the number of repeating units in 1) was 2.1.

(Synthesis Example 2) 1,3,3a, 4,5,9b
-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-
1,3-dione (specific tetracarboxylic dianhydride) 1
5.18 g (50.55 mmol) and 4,68′-diaminodiphenylmethane (diamine compound) 6.68 g (3
3.69 mmol) and 3.14 g (33.69) aniline
Was dissolved in 225 g of N-methyl-2-pyrrolidone, and reacted at room temperature for 20 minutes to obtain an amic acid compound solution. Next, N-methyl-
250 g of 2-pyrrolidone, 7.93 g of pyridine and 10.24 g of acetic anhydride were added, and the ring was dehydrated and closed at 120 ° C. for 3 hours. Thereafter, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product, and the reaction product was separated by filtration and dried at 40 ° C. for 24 hours to obtain an imide of the present invention having a logarithmic viscosity of 0.08 dl / g. Compound [This is referred to as “imide compound (A-2)”. 16.08 g was obtained. The value of the number of repeating units in this imide compound (A-2) was 1.9.

Synthesis Example 3 12.56 g (64.04 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (specific tetracarboxylic dianhydride) and 4,4
4'-diaminodiphenylmethane (diamine compound)
8.46 g (42.69 mmol) and aniline 3.98
g (42.69 mmol) was dissolved in 225 g of N-methyl-2-pyrrolidone and reacted at room temperature for 20 minutes.
An amic acid compound solution was obtained. Next, 250 g of N-methyl-2-pyrrolidone and pyridine 1 were added to the reaction solution.
0.03 g and 12.57 g of acetic anhydride were added, and 120
The ring was dehydrated at 3 ° C. for 3 hours. Thereafter, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product,
The reaction product is separated by filtration and dried at 40 ° C. for 24 hours to obtain an imide compound of the present invention having an logarithmic viscosity of 0.09 dl / g [this is referred to as “imide compound (A-3)”. 12.15 g was obtained. This imide compound (A-
The value of the number of repeating units in 3) was 2.5.

Synthesis Example 4 13.27 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (59.20)
Mmol) and 4,4'-diaminodiphenylmethane 1
1.73 g (59.20 mmol) and N-methyl-2
-Dissolved in 225 g of pyrrolidone and reacted at room temperature for 20 minutes to obtain a polyamic acid solution. Next, 250 g of N-methyl-2-pyrrolidone, 9.36 g of pyridine and 12.08 g of acetic anhydride were added to the reaction solution, and 120 g of acetic anhydride was added.
The ring was dehydrated at 6 ° C. for 6 hours. Thereafter, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product,
The reaction product was separated by filtration and dried at 40 ° C. for 24 hours to obtain a polyimide having a logarithmic viscosity of 1.10 dl / g [this is referred to as “polyimide (B-1)”. 19.8
6 g were obtained. The value of the number of repeating units in this polyimide (B-1) was 40.1.

(Synthesis Example 5) 1,3,3a, 4,5,9b
-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-
15.06 g (50.15 mmol) of 1,3-dione and 9.94 g of 4,4′-diaminodiphenylmethane (5.
0.13 mmol) and N-methyl-2-pyrrolidone 2
The polyamic acid was dissolved in 25 g and reacted at room temperature for 20 minutes to obtain a polyamic acid solution. Next, 250 g of N-methyl-2-pyrrolidone, 7.93 g of pyridine, and 10.24 g of acetic anhydride were added to the reaction solution, and the ring was dehydrated and closed at 120 ° C. for 6 hours. Thereafter, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product, and the reaction product was separated by filtration and dried at 40 ° C. for 24 hours to obtain a polyimide having a logarithmic viscosity of 1.12 dl / g. "Polyimide (B-2)". 20.75 g was obtained. The value of the number of repeating units in this polyimide (B-2) was 100.6.

(Synthesis Example 6) 1,3,3a, 4,5,9b
-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-
15.31 g (50.99 mmol) of 1,3-dione, 2.48 g (22.93 mmol) of p-phenylenediamine and 4.55 g of 4,4′-diaminodiphenylmethane
(22.95 mmol) and 2.66 g (5.00 mmol) of the diamine compound represented by the above chemical formula (1) by N
-Methyl-2-pyrrolidone was dissolved in 225 g and reacted at room temperature for 20 minutes to obtain a polyamic acid solution. Next, N-methyl-2-pyrrolidone 25 was added to the reaction solution.
0 g, 8.07 g of pyridine and 10.41 g of acetic anhydride were added, and the ring was dehydrated and closed at 120 ° C. for 6 hours. afterwards,
The reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product, and the reaction product was separated by filtration and dried at 40 ° C. for 24 hours to obtain a polyimide having a logarithmic viscosity of 1.10 dl / g. (B-3) ". 18.31 g was obtained. This polyimide (B-3)
Was 89.9.

Example 1 (1) Preparation of liquid crystal aligning agent: 50 parts by weight of imide compound (A-1) obtained in Synthesis Example 1 and 50 parts of polyimide (B-1) obtained in Synthesis Example 4 Parts by weight, and this mixture is dissolved in γ-butyrolactone to give a solid content of 5% by weight.
Was prepared. This solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent (a) of the present invention.

(2) Production of liquid crystal display element: ITO provided on one surface of a glass substrate having a thickness of 1 mm
The liquid crystal aligning agent (a) prepared as described above is coated on a transparent conductive film made of a film by a printing method using a liquid crystal alignment film coater “Angstromer” (manufactured by Nissha Printing Co., Ltd.), A coating film was formed by drying at 180 ° C. for 1 hour. The average thickness of this coating was 600 °, and the standard deviation was ±
20 °, which was excellent in uniformity of the film thickness.

The formed coating film surface was subjected to a rubbing treatment using a rubbing machine having a roll around which a nylon cloth was wound, thereby producing a liquid crystal alignment film. Here, the rubbing treatment conditions are as follows:
The rotation speed of the stage was 1 cm / sec at 0 rpm.

Two substrates on which a liquid crystal alignment film was formed as described above were prepared, and an epoxy resin-based adhesive containing aluminum oxide spheres having a diameter of 17 μm was applied to the outer edges of each substrate by screen printing. After that, the two substrates were arranged to face each other with a gap therebetween so that the rubbing directions of the respective liquid crystal alignment films were antiparallel, and the outer edges were brought into contact with each other and pressed to cure the adhesive.

A nematic liquid crystal “MLC-2001” (manufactured by Merck) is injected and filled into the cell gap defined by the adhesive on the surface of the substrate and the outer edge, and then the injection hole is sealed with an epoxy adhesive. The liquid crystal cell was constituted by stopping the operation. Thereafter, a polarizing plate was attached to the outer surface of the liquid crystal cell so that the polarization direction coincided with the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate, thereby producing a liquid crystal display device.

In the liquid crystal display device manufactured as described above, no abnormal domain was observed when the voltage was applied to and released from the liquid crystal cell, and the orientation of the liquid crystal was good.

[Examples 2 to 11] (1) Preparation of liquid crystal aligning agent: Example 1 was prepared in the same manner as in Example 1 except that the imide compound (A) and the polyimide (B) were mixed according to the formulation shown in Table 1 below. Similarly, liquid crystal aligning agents (b) to (k) of the present invention were prepared.

(2) Production of liquid crystal display element: Each of the liquid crystal aligning agents (b) to (k) was formed on a transparent conductive film composed of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm. The coating was applied by the same printing method as in Example 1, and dried at 180 ° C. for 1 hour to form a coating film. Next, the same operation as in Example 1 was performed to produce a liquid crystal display element. Table 1 below shows the average thickness and standard deviation of the coating films formed by the liquid crystal aligning agents (b) to (k), and the evaluation results of the alignment properties of the liquid crystal in the liquid crystal display device.

[0072]

[Table 1]

Comparative Example 1 The polyimide (B-2) obtained in Synthesis Example 5 was dissolved in γ-butyrolactone to prepare a solution having a solid content of 5% by weight. This solution was added with a pore size of 1μ.
A liquid crystal aligning agent (x) for comparison was prepared by filtering with a filter of m. Using this liquid crystal aligning agent (x), a liquid crystal display device was produced in the same manner as in Example 1. Although the liquid crystal alignment in the manufactured liquid crystal display element was good, the average film thickness of the coating film with the liquid crystal aligning agent (x) was 630.
Å, the standard deviation was ± 90 °, and the uniformity of the film thickness was poor.

Comparative Example 2 The imide compound (A-2) obtained in Synthesis Example 2 was dissolved in γ-butyrolactone to prepare a solution having a solid content of 5% by weight. This solution was used for pore size 1
A liquid crystal aligning agent (y) for comparison was prepared by filtering through a μm filter. Using this liquid crystal aligning agent (y), a liquid crystal display device was produced in the same manner as in Example 1. The alignment of the liquid crystal in the manufactured liquid crystal display device was good, but the average film thickness of the coating film with the liquid crystal aligning agent (y) was 620.
Å, the standard deviation was ± 140 °, and the uniformity of the film thickness was poor.

[0075]

According to the first aspect of the present invention, it is possible to provide an imide compound which is extremely useful as a component of a liquid crystal aligning agent.

According to the second aspect of the present invention, it is possible to provide a liquid crystal aligning agent having good application characteristics and capable of forming a liquid crystal alignment film having good alignment characteristics and excellent uniformity of film thickness. .

The liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention can be used not only for TN type liquid crystal display devices and STN type liquid crystal display devices but also for SH (Super Homeotropic).
It can be suitably used for forming various liquid crystal display elements such as an ic) type liquid crystal display element. In addition, a liquid crystal display device including the liquid crystal alignment film has excellent liquid crystal alignment and reliability, and can be effectively used for various devices. For example, a desk calculator, a wristwatch, a clock, a counting display,
It can be suitably used as a display device such as a word processor, a personal computer, and a liquid crystal television.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08K 5/3432 C08K 5/3432 C08L 79/08 C08L 79/08 Z G02F 1/1337 525 G02F 1/1337 525 (56) References JP-A-6-308502 (JP, A) JP-A-6-136120 (JP, A) JP-A-5-72538 (JP, A) JP-A-2-287324 (JP, A) JP-A-61-47932 (JP, A) JP-A-5-216043 (JP, A) JP-A-9-71648 (JP, A) JP-A-9-71650 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) C08G 73/00-73/26 C08L 79/00-79/08 CAPLUS (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A structure having a structure represented by the following general formula (1) :
The logarithmic viscosity (ηln) is 0.05 to 1 dl /
g is an imide compound. Embedded image 2. A liquid crystal aligning agent comprising the imide compound according to claim 1 and a polyimide having a repeating unit represented by the following general formula (2). Embedded image