JP5849391B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More particularly, the present invention relates to a liquid crystal aligning agent having excellent storage stability, particularly excellent heat resistance, and a liquid crystal display element capable of high-quality display, capable of suppressing display deterioration due to thermal stress, and capable of long-time driving.

As materials for the liquid crystal alignment film used in the liquid crystal display element, resin materials such as polyimide, polyamide, polyamic acid, and polyester are known. Especially, the liquid crystal aligning film which consists of a polyamic acid or a polyimide is excellent in heat resistance, mechanical strength, affinity with a liquid crystal, etc., and is used for many liquid crystal display elements (patent documents 1-6).
Among these, since polyamic acid has high solubility in a general-purpose organic solvent, there is an advantage that a liquid crystal aligning agent that can be easily printed in the manufacturing process of the liquid crystal display element can be obtained and the resin price is low. However, a liquid crystal display element having a liquid crystal alignment film made of polyamic acid is vulnerable to thermal stress, and when the liquid crystal display element is driven for a long time, there is a problem of a decrease in voltage holding ratio due to deterioration of the liquid crystal alignment film. . In recent years, it is designed on the assumption that the lifetime of a liquid crystal display element exceeds 10 years, as represented by a liquid crystal television. For this reason, it is important to exhibit a stable voltage holding ratio for a long time in order to maintain a high-quality display even when the liquid crystal display element is driven for a long time, and improvement of the heat resistance reliability of the alignment film is an urgent need. As a known method for improving the heat resistance reliability (heat stress resistance) of an alignment film, a method of increasing the chemical stability of the liquid crystal alignment film by blending an epoxy compound with a liquid crystal alignment agent (Patent Document) 7) A method of forming intermolecular crosslinks at the time of firing a liquid crystal alignment film by applying a polyamic acid introduced with a monomer having a carboxylic acid, thereby increasing the stability of the film is proposed (Patent Document 8). ing. However, according to these technologies, it is necessary to use a large amount of an epoxy compound or a carboxylic acid in order to exhibit the expected performance, and the reworkability of the liquid crystal alignment film (the liquid crystal alignment agent is applied when printing is poor). Ease of film peeling), rubbing resistance and the like may be impaired, and further improvement is required.

On the other hand, a liquid crystal alignment film containing polyimide has a relatively high thermal stress resistance of the obtained liquid crystal alignment film, but a conventionally known polyimide is not sufficiently soluble in a general-purpose organic solvent, so a liquid crystal alignment agent is stored. There may be problems with stability.
Under such circumstances, there is a demand for a polyamic acid / polyimide liquid crystal aligning agent that can form a liquid crystal aligning film that has sufficient solubility in general-purpose organic solvents and is excellent in heat stress resistance. ing.
Recently, a method for stereoselectively producing cyclohexanetetracarboxylic acid anhydride has been developed, and 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic acid dianhydride and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic acid diacid. It has become possible to selectively produce anhydrides (Patent Document 9, Patent Document 10 and Non-Patent Document 1). Patent Documents 9 and 10 describe polyamic acids synthesized using 100% each of the above diastereomers as tetracarboxylic dianhydrides, which are explained to be polymers having a sufficiently high molecular weight. ing. Although it is described that the polyamic acid can be used for liquid crystal alignment film applications of liquid crystal display elements, in these documents, the characteristics of the liquid crystal alignment film are not measured, and the raw material tetracarboxylic acid is used. No consideration has been given to the relationship between the structure of the dianhydride and the storage stability of the obtained liquid crystal aligning agent and the heat stress resistance of the liquid crystal aligning film formed.

JP-A-4-153622 JP 60-107020 A Japanese Patent Laid-Open No. 11-258605 JP 56-91277 A US Pat. No. 5,928,733 Japanese Patent Laid-Open No. 62-165628 JP 2008-299318 A JP 2009-157351 A JP 2009-191253 A JP 2009-286706 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 JP 2010-97188 A

Proceedings of the Society of Polymer Science, Japan, 57 (2) (2002)

The present invention has been made in view of the above circumstances, and the object thereof is a liquid crystal alignment that is excellent in storage stability and can maintain a high-quality display even when the liquid crystal display element is used for a long time. The object is to provide a liquid crystal aligning agent that gives a film.
Another object of the present invention is to provide a liquid crystal display element capable of maintaining a high-quality display even when used for a long time.
Still other objects and advantages of the present invention will become apparent from the following description.

（式（Ａ−１）中、Ｘ ^Ｉ は炭素数１〜３のアルキレン基、 ^＊ −Ｏ−、 ^＊ −ＣＯＯ−または ^＊ −ＯＣＯ−（ただし、「＊」を付した結合手がジアミノフェニル基と結合する。）であり、ａは０または１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数である。）
で表される化合物よりなる群から選択される少なくとも１種である、
そして
溶媒として、Ｎ−メチル−２−ピロリドンとエチレングリコール−ｎ−ブチルエーテルの混合物またはＮ−メチル−２−ピロリドンとエチレングリコール−ｎ−ブチルエーテルとγ−ブチロラクトンとの混合物を含有することを特徴とする、前記液晶配向剤（但し、全テトラカルボン酸二無水物のうち、１Ｓ，２Ｓ，４Ｒ，５Ｒ−シクロヘキサンテトラカルボン酸二無水物が４０〜８０モル％を占めるポリアミック酸を単独で上記重合体として含有する液晶配向剤を除く）によって達成される。 According to the present invention, the above objects and advantages of the present invention are as follows.
A liquid crystal aligning agent comprising a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, and at least one polymer selected from the group consisting of polyimides formed by dehydrating and ring-closing the polyamic acid,
The tetracarboxylic dianhydride is
At least one selected from the group consisting of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride, all tetracarboxylic dianhydrides der those containing 5 to 80 mol% with respect to is,
The diamine is
(I) It consists of 100 mol% of the following specific diamine 1 or contains 50 mol% or more of the following specific diamine 1 and 30 mol% or less of the following specific diamine 2 or
(Ii) The following specific diamine 1 20 to 97 mol% and the following specific diamine 2 3 to 80 mol%,
The specific diamine 1 is p-phenylenediamine, 3,5-diaminobenzoic acid, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 2,2′-dimethyl-4,4′-diaminobiphenyl, At least selected from the group consisting of 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-diaminodiphenylamine and 4,4 ′-(m-phenylenediisopropylidene) dianiline 1 type, and the specific diamine 2 is cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2, 4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, 3,5-diaminobenzoic acid co Suteniru, 3,5-diaminobenzoic acid Ranosutaniru, 3,6-bis (4-benzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane and the following formula (A-1):

(In the formula (A-1), ^{X I} is an alkylene group having 1 to 3 carbon ^atoms, * ^-O-, * -COO- or ^* -OCO- (where bond marked with "*" is diaminophenyl group And a is 0 or 1, b is an integer of 0 to 2, and c is an integer of 1 to 20.)
Is at least one selected from the group consisting of compounds represented by:
And
As a solvent, characterized that you containing a mixture or N- methyl-2-pyrrolidone and mixtures of ethylene glycol -n- butyl ether and γ- butyrolactone N- methyl-2-pyrrolidone and ethylene glycol -n- butyl ether The liquid crystal aligning agent (however, the polyamic acid in which 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride occupies 40 to 80 mol% of all tetracarboxylic dianhydrides alone is used as the polymer. Ru is achieved by excluding the liquid crystal aligning agent) containing.

The liquid crystal aligning agent of the present invention is excellent in storage stability and provides a liquid crystal aligning film capable of maintaining high-quality display even when used for a long time when used in a liquid crystal display element. Therefore, the liquid crystal display element of the present invention having a liquid crystal alignment film formed from such a liquid crystal aligning agent can maintain a high-quality display even when used for a long time.
The liquid crystal display element of the present invention can be effectively applied to various devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, personal digital assistants, digital cameras, mobile phones, and various monitors. It can be suitably used for a display device such as a liquid crystal television.

The liquid crystal aligning agent of the present invention is
A liquid crystal aligning agent comprising a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, and at least one polymer selected from the group consisting of polyimides obtained by dehydrating and ring-closing the polyamic acid. ,
The tetracarboxylic dianhydride is
At least one selected from the group consisting of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride, all tetracarboxylic dianhydrides 5 to 80 mol% is included.
A polyamic acid obtained by reacting such a specific tetracarboxylic dianhydride and a diamine, and at least one polymer selected from the group consisting of polyimides obtained by dehydrating and ring-closing the polyamic acid, Hereinafter, it may be referred to as “specific polymer” in the book.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride for synthesizing the polyamic acid in the present invention is 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride. At least one selected from the group consisting of and other tetracarboxylic dianhydrides are used in combination.
Here, at least one total tetracarboxylic anhydride selected from the group consisting of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride Although the usage-ratio with respect to a thing is 5-80 mol%, it is preferable that this is included 10-60 mol%, and it is more preferable that it is 15-50 mol%. When this proportion is less than 5 mol%, the heat-resistant reliability of the liquid crystal alignment film to be formed may be inferior. On the other hand, when it exceeds 80 mol%, the storage stability of the obtained liquid crystal alignment film may be inferior. This is not preferable.
More preferably, the tetracarboxylic dianhydride contains 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride in the above range.

Examples of the other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- No 1,2-dicarboxylic acid 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 4,6: 8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone and the like;
As aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride can be mentioned, respectively,
Tetracarboxylic dianhydrides described in Patent Document 14 (Japanese Patent Laid-Open No. 2010-97188) can be used.

Examples of the other tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- 1,2-dicarboxylic acid Water, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane- Selected from the group consisting of 2: 4,6: 8-dianhydride and 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone It preferably contains at least one (hereinafter referred to as “specific tetracarboxylic dianhydride”).
The use ratio of the specific tetracarboxylic dianhydride is preferably 50 mol% or more, more preferably 80 mol% or more, based on the total of the other tetracarboxylic dianhydrides. It is particularly preferred that it is mol%.

<Diamine>
Examples of the diamine used for synthesizing the polyamic acid in the present invention include aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane and the like. Specific examples thereof include aliphatic diamines such as 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;
Examples of aromatic diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenylamine, 1,5-diaminonaphthalene, 2,2′-dimethyl- 4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4 -(4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis ( 4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, , 4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3, 4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N- Phenyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, 1,4-bis -(4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid, cholestanyloxy-3,5-diaminobenzene, cholestenyl Oxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, 3, , 5-Diaminobenzoic acid lanostannyl, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl- 3,5-diaminobenzoate, 4- (4′-trifluoromethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butyl Cyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) 4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4 -Heptylcyclohexyl) cyclohexane and the following formula (A-1)

(In the formula (A-1), ^{X I} is an alkylene group having 1 to 3 carbon ^atoms, * ^-O-, * -COO- or ^* -OCO- (where bond marked with "*" is diaminophenyl group And a is 0 or 1, b is an integer of 0 to 2, and c is an integer of 1 to 20.)
A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, respectively.
Diamines described in Patent Document 14 (Japanese Patent Laid-Open No. 2010-97188) can be used.
The ^{X I} in the above formula (A-1) an alkylene group having 1 to 3 carbon ^atoms, * -O- or ^* -COO- (provided that a bond marked with "*" is bonded to the diamino phenyl group.) In Preferably there is. Specific examples of the group C _c H _{2c + 1} — include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n -Nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n -An eicosyl group etc. can be mentioned. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to the other groups.
Specific examples of the compound represented by the formula (A-1) include, for example, dodecanoxy-2,4-diaminobenzene, tetradecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2, 4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, tetradecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, Octadecanoxy-2,5-diaminobenzene, the following formulas (A-1-1) to (A-1-3)

And the like, and the like.
In the above formula (A-1), it is preferable that a and b are not 0 at the same time.
The diamine is p-phenylenediamine, 3,5-diaminobenzoic acid, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4, At least one selected from the group consisting of 4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4'-diaminodiphenylamine and 4,4 '-(m-phenylenediisopropylidene) dianiline (hereinafter, referred to as a "specific diamine 1".) Ru der those containing.

When the liquid crystal aligning agent of the present invention is used for forming a liquid crystal alignment film in a vertical alignment (VA) liquid crystal display element, in addition to the specific diamine as described above, cholestanyloxy-3 , 5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, 3, Cholestenyl 5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane and the above formula (A-1) And at least one selected from the group consisting of compounds represented by (hereinafter referred to as “specific diamine 2”). Dressings Ru Der.
When the liquid crystal aligning agent of the present invention are those used for forming the liquid crystal alignment film of the liquid crystal display device of a vertical alignment type VA type, that use a percentage against the total diamine of the specific diamine 1 and specific diamine 2, It is as follows.
Specific diamine 1: 20-97%, more preferably 50-95%, particularly preferably 60-90%
Specific diamine 2: 3 to 80 mol%, more preferably 5 to 50%, particularly preferably 10 to 40%
In this case, it is preferable that the total use ratio of the specific diamine 1 and the specific diamine 2 is 100 mol% with respect to the total diamine.

On the other hand, the liquid crystal aligning agent of the present invention is a liquid crystal display element other than the VA type (for example, TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, lateral electric field type (for example, IPS (In-Plane Switching), FFS (Fringe Field)). In the case where the liquid crystal alignment film is used in the formation of the liquid crystal alignment film in the switching etc.), the preferred use ratio of the specific diamine 1 and the specific diamine 2 to the total diamine is as described below.
Specific diamine 1: 50 mol% or more, more preferably 80 mol% or more, particularly preferably 100 mol%
Specific diamine 2 : 30 mol% or less, more preferably 10% or less, particularly preferably 0 mol%
In this case, as a diamine, it is preferable to make the sum total of the said specific diamine 1 and the specific diamine 2 into 100 mol%, and it is more preferable to use only the specific diamine 1.

<Molecular weight regulator>
In synthesizing the polyamic acid, a terminal-modified polymer may be synthesized using an appropriate molecular weight regulator together with the tetracarboxylic dianhydride and dimian as described above. A liquid crystal aligning agent containing at least one polymer selected from the group consisting of a polyamic acid and a polyimide formed by dehydrating and cyclizing the polyamic acid by using the polyamic acid as a terminal-modified polymer is the present invention. The applicability (printability) is further improved without impairing the effect.
Examples of the molecular weight regulator include acid monoanhydrides, monoamine compounds, monoisocyanate compounds, and the like. Specific examples of these acid monoanhydrides include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic acid. Nic acid anhydride, n-hexadecyl succinic acid anhydride, etc .;
Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine;
Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine used.

<Synthesis of polyamic acid>
The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, More preferably, it is the ratio which becomes 0.3-1.2 equivalent.
The polyamic acid synthesis reaction is preferably carried out in an organic solvent, preferably at -20 ° C to 150 ° C, more preferably at 0-100 ° C, preferably 0.1-24 hours, more preferably 0.5-12 hours. Done.
Here, examples of the organic solvent include an aprotic polar solvent, phenol and derivatives thereof, alcohol, ketone, ester, ether, halogenated hydrocarbon, and hydrocarbon.
Specific examples of these organic solvents include, for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea as the aprotic polar solvent. Hexamethylphosphotriamide, etc .;
Examples of the phenol derivative include m-cresol, xylenol, halogenated phenol and the like;
Examples of the alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and ethylene glycol monomethyl ether;
Examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone;

Examples of the ester include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, and diethyl malonate;
Examples of the ether include 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 diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran and the like;
Examples of the halogenated hydrocarbon include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene and the like;
Examples of the hydrocarbon include hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, and diisopentyl ether.

Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and phenol and derivatives thereof (first group organic solvent), or one selected from the first group of organic solvents It is preferable to use a mixture of the above and one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second group organic solvent). In the latter case, the proportion of the organic solvent of the second group is preferably 50% by weight or less, more preferably 40% by weight or less, based on the total of the first group of organic solvents and the second group of organic solvents. Furthermore, it is preferable that it is 30 weight% or less.
The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. It is preferable.
As described above, a reaction solution obtained by dissolving polyamic acid is obtained.
This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction. Isolation and purification of the polyamic acid can be performed according to a known method.

<Synthesis of polyimide>
The polyimide can be obtained by dehydrating and ring-closing the polyamic acid synthesized as described above to imidize.
The polyimide in the present invention may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure that the polyamic acid that is a precursor thereof has, or by dehydrating and cyclizing only a part of the amic acid structure, A partially imidized product in which a structure and an imide ring structure coexist may be used. The polyimide in the present invention preferably has an imidation ratio of 30% or more, more preferably 50% or more, and particularly preferably 55% or more. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.
The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating if necessary. . Of these, the latter method is preferred.

In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.
In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. It may be used for the preparation of a liquid crystal aligning agent or may be used for the preparation of a liquid crystal aligning agent after purifying the isolated polyimide. These purification operations can be performed according to known methods.

<Solution viscosity of polymer>
The specific polymer obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, and a solution viscosity of 30 to 500 mPa · s, when this is a 10% by weight solution. It is more preferable that it has.
The solution viscosity (mPa · s) of the above polymer is E for a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

<Other additives>
The liquid crystal alignment film of the present invention contains the specific polymer as described above as an essential component, but may contain other components as necessary. Examples of such other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), and functional silane compounds.

[Other polymers]
These other polymers can be used to improve solution and electrical properties. Such other polymer is a polymer other than the specific polymer, for example, a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, and 1S, The content ratio of at least one selected from the group consisting of 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride is less than 5 mol% Or more than 80 mol% of the polyamic acid (hereinafter referred to as “other polyamic acid”), a polyimide obtained by dehydrating and ring-closing the polyamic acid (hereinafter referred to as “other polyimide”), polyamic acid ester , Polyester, polyamide, polysiloxane, cellulose derivatives, polyacetal, polystyrene derivatives , Poly - can be exemplified (styrene-phenylmaleimide) derivative, poly (meth) acrylate and the like. Of these, other polyamic acids or other polyimides are preferred, and other polyamic acids are more preferred.

The tetracarboxylic dianhydride used for synthesizing the other polyamic acid or other polyimide is as described above as the other tetracarboxylic dianhydride preferably used for synthesizing a specific polymer. The same may be mentioned but preferably 1,2,3,4-cyclobutanetetracarboxylic dianhydride, pyromellitic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 1 , 3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione It is preferable to use at least one kind.
As the diamine used for synthesizing the other polyamic acid or other polyimide, it is possible to use at least one selected from those exemplified above as the diamine used when synthesizing the specific polymer. preferable. Diamines used to synthesize other polyamic acids or other polyimides include 4,4′-diaminodiphenylmethane, 2,2′-dimethyl-4,4′-diaminobiphenyl, and cholestanyloxy-2,4- It is preferable to use at least one selected from the group consisting of diaminobenzene, 3,5-diaminobenzoic acid and 1,4-bis- (4-aminophenyl) -piperazine.
The proportion of the other polymer used is preferably 50% by weight or less, more preferably 40% by weight based on the total of the polymers (the above-mentioned specific polymer and other polymers are the same hereinafter). It is preferably not more than wt%, more preferably not more than 30 wt%. In the case of using other polymers, if the use ratio is 0.1% by weight or more based on the total amount of the polymers, the effect of the addition is significantly expressed.

[Epoxy compound]
The epoxy compound can be contained in the liquid crystal aligning agent of the present invention for the purpose of further improving the adhesion and heat resistance of the obtained liquid crystal aligning film to the substrate.
The epoxy compound is preferably an epoxy compound having two or more epoxy groups in the molecule, such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol. Diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N Preferred are N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, N, N-diglycidyl-benzylamine, N, N-diglycidyl-aminomethylcyclohexane, N, N-diglycidyl-cyclohexylamine and the like. Can be mentioned.
When the use ratio of the epoxy compound is too small, the desired effect as described above is not sufficiently exhibited. On the other hand, when the use ratio is excessive, the reworkability and rubbing resistance of the liquid crystal alignment film are impaired. From this viewpoint, the compounding ratio of the epoxy compound is preferably 30 parts by weight or less, more preferably 0.1 to 15 parts by weight, and more preferably 0.5 to 100 parts by weight of the total amount of the polymer. It is more preferable to set it as -8 weight part, and it is preferable to set it as 1-3 weight part especially.

[Functional silane compounds]
Examples of the functional silane compound include 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-aminopropyl Trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4 7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9- Triethoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazananoate, methyl 9-triethoxysilyl-3,6-diazananoate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxy Methyltriethoxysilane, 2-glycidoxyethyltrimeth Shishiran, 2-glycidoxyethyl triethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyl triethoxy silane and the like.
The blending ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of the polymer.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is constituted by dissolving the specific polymer as described above and other additives optionally blended as required, preferably dissolved in an organic solvent.
Examples of the organic solvent used in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy- 4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether , Ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl Ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. Can be mentioned. These can be used alone or in admixture of two or more.

The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably, when heated, a liquid crystal alignment film or a liquid crystal alignment film is formed. When the concentration is less than 1% by weight, the film thickness of the coating film is too small to obtain a good liquid crystal alignment film, while when the solid content concentration exceeds 10% by weight, The film thickness becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.
The particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when the spinner method is used, a solid content concentration of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention as described above. More specifically, the liquid crystal display element of the present invention is formed by disposing polarizing plates on both outer surfaces of a liquid crystal cell, and the liquid crystal cell includes two substrates having a liquid crystal alignment film on each liquid crystal alignment film surface. The liquid crystal layer is sandwiched between the opposingly arranged gaps, and the liquid crystal alignment film is formed from the liquid crystal aligning agent of the present invention.
Such a liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3). In step (1), the substrate to be used varies depending on the desired operation mode. Steps (2) and (3) are common to each operation mode.
(1) First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.

(1-1) When manufacturing a TN type, STN type, or VA type liquid crystal display element, each of the transparent conductive film forming surfaces is a pair of two substrates having a patterned transparent conductive film provided on one side. Further, the liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method or an ink jet printing method, respectively, and then each coated surface is heated to form a coating film. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly (alicyclic olefin) can be used. As the transparent conductive film provided on one side of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. In order to obtain a patterned transparent conductive film which can be used, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a mask having a desired pattern when forming the transparent conductive film The method using can be used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or functional titanium is formed on the surface of the substrate surface on which the coating film is to be formed. You may give the pretreatment which apply | coats a compound etc. previously.
After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat-imidating a polyamic acid as needed. The firing (post-bake) temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C, and the post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. Thus, the film thickness of the formed film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(1-2) On the other hand, when manufacturing a horizontal electric field type liquid crystal display element, a conductive film forming surface of a substrate on which a transparent conductive film patterned in a comb shape is provided on one side, and a conductive film are provided. The liquid crystal aligning agent of this invention is each apply | coated to the single side | surface of a counter substrate which does not exist, Then, a coating film is formed by heating each coating surface.
Material of substrate and transparent conductive film used at this time, patterning method of transparent conductive film, pretreatment of substrate, application method of liquid crystal aligning agent, heating method after applying liquid crystal aligning agent, and film of coating film to be formed The thickness is the same as (1-1) above.

(2) When the liquid crystal display element manufactured by the method of the present invention is a VA liquid crystal display element, the coating film formed as described above can be used as a liquid crystal alignment film as it is. If desired, it may be used after the following rubbing treatment.
On the other hand, when manufacturing a liquid crystal display element other than the VA type, a rubbing treatment is performed on the coating film formed as described above to obtain a liquid crystal alignment film.
The rubbing treatment can be performed by rubbing the coating film surface formed as described above with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton in a certain direction. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film.
Furthermore, for the liquid crystal alignment film formed as described above, for example, a process of changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays (Patent Document 11). Japanese Patent Laid-Open No. 6-222366) and Patent Document 12 (Japanese Patent Laid-Open No. 6-281937)), a rubbing process is performed in a direction different from the previous rubbing process after a resist film is formed on a part of the liquid crystal alignment film surface. After that, the resist film is removed to improve the visual field characteristics of the liquid crystal display element obtained by making the liquid crystal alignment film have different liquid crystal alignment ability for each region (Patent Document 13 -107544) and the like.

(3) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates opposed to each other. Here, when the rubbing process is performed on the coating film, the two substrates are disposed to face each other so that the rubbing directions in the respective coating films are at a predetermined angle, for example, orthogonal or antiparallel.
In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped to predetermined locations on the surface of the liquid crystal alignment film. Thereafter, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal cell. be able to.

Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase, and then gradually cooled to room temperature, so that the flow alignment during liquid crystal injection is achieved. It is desirable to remove.
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell.
Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.
As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal, and the like can be used. Among these, a nematic liquid crystal is preferable. For example, a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenyl cyclohexane liquid crystal, and an ester liquid crystal. Terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, and the like can be used. In addition, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names C-15 and CB-15 (Merck); Ferroelectric liquid crystals such as siloxybenzylidene-p-amino-2-methylbutylcinnamate may be further added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The solution viscosity of each polymer solution and the imidization ratio of polyimide in the polymerization examples were measured by the following methods .
[Solution viscosity of the polymer solution]
The solution viscosity (mPa · s) of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer in the solvents and concentrations described in each synthesis example.
[Imidation rate of polyimide]
A solution of polyimide was collected a small amount fraction was poured into pure water, was thoroughly dried under reduced pressure at room temperature and the resulting precipitate was dissolved in deuterated dimethyl sulfoxide, at room temperature with tetramethylsilane as a reference substance ¹ H- NMR was measured. From the obtained ¹ H-NMR spectrum, the imidization ratio was determined by the formula shown by the following formula (1).
Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), ^{A 1} is the peak area derived from proton of NH group appearing in the vicinity of the chemical shift 10 ppm,
A ² is the peak area derived from other protons,
α is the number ratio of other protons to one NH proton in the polymer precursor (polyamic acid). )

<Synthesis and Stability Evaluation of Polymer for TN Type Liquid Crystal Alignment Agent>
[Synthesis example of polyamic acid as specific polymer]
Synthesis Example A-TN1
1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride 112 g (0.50 mol) and pyromellitic dianhydride 109 g (0.50 mol) as tetracarboxylic dianhydride and 4,4 ′ as diamine -198 g (1.0 mol) of diaminodiphenylmethane was dissolved in a mixed solvent consisting of 246 g of N-methyl-2-pyrrolidone and 2,213 g of γ-butyllactone, and reacted at 40 ° C for 3 hours to give a polyamic acid ( A solution containing 15% by weight of A-TN1) was obtained. The solution viscosity of this solution was 179 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example A-TN2
1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride 67 g (0.30 mol) and pyromellitic dianhydride 153 g (0.70 mol) as tetracarboxylic dianhydride and 4,4 ′ as diamine -198 g (1.0 mol) of diaminodiphenylmethane was dissolved in a mixed solvent consisting of 246 g of N-methyl-2-pyrrolidone and 2,213 g of γ-butyllactone, and reacted at 40 ° C for 3 hours to give a polyamic acid ( A solution containing 15% by weight of A-TN2) was obtained. The solution viscosity of this solution was 153 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis examples of other polyamic acids]
Synthesis Example a-TN3
109 g (0.50 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 98 g (0.50 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 4,4 ′ as diamine -198 g (1.0 mol) of diaminodiphenylmethane was dissolved in a mixed solvent consisting of 230 g of N-methyl-2-pyrrolidone and 2,068 g of γ-butyllactone, and reacted at 40 ° C for 3 hours to give a polyamic acid ( A solution containing 15% by weight of a-TN3) was obtained. The solution viscosity of this solution was 193 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis example of polyimide as a specific polymer]
Synthesis example B-TN1
As tetracarboxylic dianhydride, 112 g (0.50 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride As a diamine, 106 g (0.985 mol) of p-phenylenediamine and 7.8 g (0.015 mol) of 3 (3,5-diaminobenzoyloxy) cholestane were dissolved in 3,042 g of N-methyl-2-pyrrolidone. By reacting at 60 ° C. for 6 hours, a solution containing polyamic acid was obtained. The solution viscosity of the polyamic acid solution obtained here was 160 mPa · s.
3,380 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 395 g of pyridine and 306 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone (the pyridine and acetic anhydride used in the imidization reaction were removed from the system in the present operation, the same applies hereinafter), and further concentrated. Thus, a solution containing 10% by weight of polyimide (B-TN1) having an imidation ratio of about 94% was obtained.
A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a concentration of 6% by weight was 28 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis example of other polyimides]
Synthesis example b-TN2
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione 155 g (0.50 mol), p-phenylenediamine 92 g (0.87 mol) as diamine, bisamino 25 g (0.10 mol) of propyltetramethyldisiloxane and 13 g (0.02 mol) of 3,6-bis (4-aminobenzoyloxy) cholestane and 2.7 g (0.030 mol) of aniline as monoamine were added to N-methyl. 2-Pyrrolidone was dissolved in 960 g and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 59 mPa · s.
Next, 2,700 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 396 g of pyridine and 409 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone, and further concentrated to obtain about 2,520 g of a solution containing 15% by weight of polyimide (b-TN2) having an imidation ratio of about 95%. Got. A small amount of this polyimide solution was sampled, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 6.0% by weight was 18 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis example b-TN3
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 106 g (0.985 mol) of p-phenylenediamine and 3 (3,5-diaminobenzoyl) as diamine Oxy) cholestane (7.8 g, 0.015 mol) was dissolved in 3,042 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. The solution viscosity of the polyamic acid solution obtained here was 181 mPa · s.
3,380 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 395 g of pyridine and 306 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone, and further concentrated to obtain a solution containing 10% by weight of polyimide (b-TN3) having an imidation ratio of about 95%.
A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a concentration of 6% by weight was 35 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

<Synthesis and Evaluation of Stability of Polymer for VA Type Liquid Crystal Alignment Agent>
[Synthesis example of polyimide as a specific polymer]
Synthesis example B-VA
As tetracarboxylic dianhydride, 112 g (0.50 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride As a diamine, 52 g (0.1 mol) of cholestanyl 3,5-diaminobenzoate, 49 g (0.1 mol) of cholestanyloxy-2,4-diaminobenzene and 87 g (0.80 mol) of p-phenylenediamine were added. -Methyl-2-pyrrolidone was dissolved in 1,652 g and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 79 mPa · s.
Next, 3,835 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 79 g of pyridine and 102 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (B-VA1) having an imidation ratio of about 51%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 102 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis example B-VA2
1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride 112 g (0.50 mol) and 2,3,5-tricarboxycyclopentylacetic acid dianhydride 112 g (0.50 mol) as tetracarboxylic dianhydrides As a diamine, 52 g (0.1 mol) of cholestanyl 3,5-diaminobenzoate, 49 g (0.1 mol) of cholestanyloxy-2,4-diaminobenzene and 87 g (0.80 mol) of p-phenylenediamine were added. -Methyl-2-pyrrolidone was dissolved in 1,652 g and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight. The solution viscosity was 71 mPa · s.
Next, 3,835 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 79 g of pyridine and 102 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (B-VA2) having an imidization ratio of about 48%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 99 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis example B-VA3
As tetracarboxylic dianhydride, 45 g (0.20 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 180 g (0.80 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride In addition, 105 g (0.20 mol) of cholestanyl 3,5-diaminobenzoate and 87 g (0.80 mol) of p-phenylenediamine were dissolved in 1,663 g of N-methyl-2-pyrrolidone as a diamine, and the mixture was heated at 60 ° C. for 6 hours. Reaction was performed and the polyamic acid solution was obtained. A small amount of the obtained polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 59 mPa · s.
Next, 3,861 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 79 g of pyridine and 102 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (B-VA3) having an imidization ratio of about 47%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 80 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis example B-VA4
As tetracarboxylic dianhydride, 45 g (0.20 mol) of 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride and 180 g (0.80 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride As a diamine, 105 g (0.20 mol) of cholestanyl 3,5-diaminobenzoate and 87 g (0.80 mol) of p-phenylenediamine were dissolved in 1,663 g of N-methyl-2-pyrrolidone, and the mixture was heated at 60 ° C. for 6 hours. Reaction was performed and the polyamic acid solution was obtained. A small amount of the obtained polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 66 mPa · s.
Next, 3,861 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 79 g of pyridine and 102 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (B-VA3) having an imidization ratio of about 50%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 89 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis example B-VA5
1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride 135 g (0.60 mol) and 2,3,5-tricarboxycyclopentylacetic dianhydride 90 g (0.40 mol) as tetracarboxylic dianhydrides As a diamine, 105 g (0.20 mol) of cholestanyl 3,5-diaminobenzoate, 65 g (0.60 mol) of p-phenylenediamine and 30 g (0.20 mol) of 3,5 diaminobenzoic acid were added to N-methyl-2. -Dissolved in 1,697 g of pyrrolidone and reacted at 60 ° C for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight, and the viscosity was 50 mPa · s.
Next, 3,939 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 119 g of pyridine and 153 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (B-VA5) having an imidization ratio of about 66%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 79 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis example B-VA6
45 g (0.20 mol) of 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 179 g (0.80 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride As a diamine, 131 g (0.25 mol) of cholestanyl 3,5-diaminobenzoate, 53 g (0.50 mol) of p-phenylenediamine and 38 g (0.25 mol) of 3,5 diaminobenzoic acid were added to N-methyl-2. -Dissolved in 1,697 g of pyrrolidone and reacted at 60 ° C for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 58 mPa · s.
Next, 3,939 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 119 g of pyridine and 153 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (B-VA6) having an imidization ratio of about 69%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 81 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis example of other polyimides]
Synthesis example b-VA7
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 52 g (0.10 mol) of cholestanyl 3,5-diaminobenzoate as diamine, cholestanyloxy- 49 g (0.10 mol) of 2,4-diaminobenzene and 87 g (0.80 mol) of p-phenylenediamine were dissolved in 1,652 g of N-methyl-2-pyrrolidone, reacted at 60 ° C. for 6 hours, and polyamic An acid solution was obtained. A small amount of the obtained polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 70 mPa · s.
Next, 3,835 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 79 g of pyridine and 102 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (b-VA7) having an imidization ratio of about 49%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 80 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example b-VA8
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 105 g (0.20 mol) of cholestanyl 3,5-diaminobenzoate as diamine, p-phenylenediamine 65 g (0.60 mol) and 3,5 diaminobenzoic acid 30 g (0.20 mol) are dissolved in 1,697 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. It was. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight, and the viscosity was 50 mPa · s.
Next, 3,939 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 119 g of pyridine and 153 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (b-VA8) having an imidization ratio of about 67%. . A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 73 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

<Synthesis and stability evaluation of polymer for IPS type liquid crystal aligning agent>
[Synthesis example of polyamic acid as specific polymer]
Synthesis Example A-IPS1
1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride 45 g (0.20 mol) and pyromellitic dianhydride 174 g (0.80 mol) as tetracarboxylic dianhydride and p-phenylenediamine as diamine 108 g (1.0 mol) was dissolved in 1,900 g of N-methyl-2-pyrrolidone and reacted at 40 ° C. for 3 hours to obtain a solution containing 15% by weight of polyamic acid (A-IPS1). .
A small amount of this solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 75 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis examples of other polyamic acids]
Synthesis Example a-IPS2
Synthesis except that 190 g (0.85 mol) of 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride and 33 g (0.15 mol) of pyromellitic dianhydride were used as tetracarboxylic dianhydrides. In the same manner as in Example A-IPS1, a solution containing 15% by weight of polyamic acid (a-IPS2) was obtained.
A small amount of this solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 63 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, gelation was observed and the storage stability was poor.
The polyamic acid (a-IPS2) was not further evaluated.

[Synthesis example of polyamic acid as specific polymer]
Synthesis Example A-IPS3
180 g (0.80 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 44 g (0.20 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 4,4 ′ as diamine -Polyamic acid was obtained by dissolving 160 g (0.80 mol) of diaminodiphenyl ether and 110 g (0.20 mol) of p-phenylenediamine in 2,300 g of N-methyl-2-pyrrolidone and reacting at 40 ° C for 3 hours. A solution containing 15% by weight of (A-IPS3) was obtained.
A small amount of this solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 74 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example A-IPS4
Synthesis example, except that 180 g (0.80 mol) of 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride and 44 g (0.20 mol) of pyromellitic dianhydride were used as tetracarboxylic dianhydrides. A solution containing 15% by weight of polyamic acid (A-IPS4) was obtained in the same manner as A-IPS3.
A small amount of this solution was taken, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight. The solution viscosity was 60 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example A-IPS5
180 g (0.80 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 44 g (0.20 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 4,4 ′ as diamine A solution containing 15% by weight of polyamic acid (A-IPS5) by dissolving 200 g (1.0 mol) of diaminodiphenylamine in 2,400 g of N-methyl-2-pyrrolidone and reacting at 40 ° C. for 3 hours. Got.
A small amount of this solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 65 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example A-IPS6
180 g (0.80 mol) of 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride and 44 g (0.20 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 4,4 ′ as diamine -15% of polyamic acid (A-IPS6) in the same manner as in Synthesis Example A-IPS5 except that 100 g (0.50 mol) of diaminodiphenyl ether and 100 g (0.50 mol) of 4,4'-diaminodiphenylamine were used. A solution containing% by weight was obtained.
A small amount of this solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 70 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis examples of other polyamic acids]
Synthesis Example a-IPS7
224 g (1.0 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride as the tetracarboxylic dianhydride and 108 g (1.0 mol) of p-phenylenediamine as the diamine were added to N-methyl-2- By dissolving in 1,900 g of pyrrolidone and reacting at 40 ° C. for 3 hours, a solution containing 15% by weight of polyamic acid (a-IPS7) was obtained.
A small amount of this solution was sampled, and N-methyl-2-pyrrolidone was added thereto, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 99 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, gelation was observed and the storage stability was poor.
This polyamic acid (a-IPS7) was not further evaluated.

Synthesis Example a-IPS8
Polyamic acid (a-IPS8) in the same manner as in Synthesis Example A-IPS5, except that 224 g (1.0 mol) of 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride was used as tetracarboxylic dianhydride. Of 15% by weight was obtained.
Although this solution was in the form of a solution at the reaction temperature (40 ° C.), gelation occurred in the process of cooling to room temperature, and thus the viscosity could not be measured.
This polyamic acid (a-IPS8) was not further evaluated.

Synthesis Example a-IPS9
40 g of pyromellitic dianhydride (1.0 mol) as tetracarboxylic dianhydride and 110 g (1.0 mol) of p-phenylenediamine as diamine were dissolved in 1,800 g of N-methyl-2-pyrrolidone. By reacting at 3 ° C. for 3 hours, a solution containing 15% by weight of polyamic acid (a-IPS9) was obtained.
The solution viscosity of this solution was 180 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example a-IPS10
220 g (1.0 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride, 160 g (0.80 mol) of 4,4′-diaminodiphenyl ether and 22 g (0.20 mol) of p-phenylenediamine as diamine A solution containing 15% by weight of polyamic acid (a-IPS10) was obtained by dissolving in 2,300 g of N-methyl-2-pyrrolidone and reacting at 40 ° C. for 3 hours.
A small amount of this solution was collected, and the viscosity of the solution measured as a solution having a polyamic concentration of 10% by weight by adding N-methyl-2-pyrrolidone was 71 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example a-IPS11
200 g (0.90 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 20 g (0.10 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 4,4 ′ as diamine -Polyamic acid was prepared by dissolving 160 g (0.80 mol) of diaminodiphenyl ether and 22 g (0.20 mol) of p-phenylenediamine in 2,300 g of N-methyl-2-pyrrolidone and reacting at 40 ° C for 3 hours. A solution containing 15% by weight of (a-IPS11) was obtained.
A small amount of this solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 77 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis example of polyimide as a specific polymer]
Synthesis Example B-IPS1
As tetracarboxylic dianhydride, 112 g (0.50 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride As a diamine, 86 g (0.80 mol) of p-phenylenediamine, 23 g (0.10 mol) of 4,4′-diaminodiphenylmethane and 32 g (0.10 mol) of 4,4′-bis (trifluoromethyl) biphenyl were used. Dissolved in 2,100 g of N-methyl-2-pyrrolidone and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 40 mPa · s.
Next, 2,800 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 400 g of pyridine and 310 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with γ-butyrolactone, and then concentrated to obtain 2,300 g of a solution containing 15% by weight of polyimide (B-IPS1) having an imidation ratio of about 92%. . A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the viscosity measured as a solution having a polyimide concentration of 10% by weight was 36 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example B-IPS2
1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride 112 g (0.50 mol) and 2,3,5-tricarboxycyclopentylacetic acid dianhydride 112 g (0.50 mol) as tetracarboxylic dianhydrides A polyamic acid solution was obtained in the same manner as in Synthesis Example B-IPS1 except that was used. A small amount of this solution was taken and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 35 mPa · s.
Next, after performing a dehydration ring-closing reaction in the same manner as in Synthesis Example B-IPS1, the solvent in the system was replaced with γ-butyrolactone and then concentrated to obtain a polyimide having an imidation ratio of about 94% (B-IPS2). 2,300 g of a solution containing 15 wt% was obtained. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the viscosity measured as a solution having a polyimide concentration of 10% by weight was 34 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example B-IPS3
As tetracarboxylic dianhydride, 112 g (0.50 mol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride In addition, 97 g (0.90 mol) of p-phenylenediamine and 32 g (0.10 mol) of 4,4′-bis (trifluoromethyl) biphenyl were dissolved in 2,000 g of N-methyl-2-pyrrolidone as a diamine, Reaction was performed at 0 degreeC for 3 hours, and the polyamic acid solution was obtained. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 46 mPa · s.
Next, 2,700 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 400 g of pyridine and 310 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with γ-butyrolactone and then concentrated to obtain 2,300 g of a solution containing 15% by weight of polyimide (B-IPS3) having an imidation ratio of about 93%. . A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 42 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example B-IPS4
1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride 112 g (0.50 mol) and 2,3,5-tricarboxycyclopentylacetic acid dianhydride 112 g (0.50 mol) as tetracarboxylic dianhydrides A polyamic acid solution was obtained in the same manner as in Synthesis Example B-IPS3 except that was used. A small amount of this solution was collected, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight with addition of N-methyl-2-pyrrolidone was 35 mPa · s.
Subsequently, after performing a dehydration ring closure reaction in the same manner as in Synthesis Example B-IPS3, the solvent in the system was replaced with γ-butyrolactone and then concentrated to obtain a polyimide having an imidization ratio of about 91% (B-IPS4). 2,300 g of a solution containing 15 wt% was obtained. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 33 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis example of other polyimides]
Synthesis Example b-IPS5
A polyamic acid solution was obtained in the same manner as in Synthesis Example B-IPS1 except that 220 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride was used as the tetracarboxylic dianhydride. A small amount of this solution was taken and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 48 mPa · s.
Next, after performing a dehydration ring-closing reaction in the same manner as in Synthesis Example B-IPS1, the solvent in the system was replaced with γ-butyrolactone and then concentrated to obtain a polyimide having an imidation ratio of about 93% (b-IPS5). 2,300 g of a solution containing 15 wt% was obtained. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the viscosity measured as a solution having a polyimide concentration of 10% by weight was 45 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

Synthesis Example b-IPS6
A polyamic acid solution was obtained in the same manner as in Synthesis Example B-IPS4 except that 220 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride was used as the tetracarboxylic dianhydride. A small amount of this solution was taken and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 45 mPa · s.
Subsequently, after performing a dehydration ring-closing reaction in the same manner as in Synthesis Example B-IPS4, the solvent in the system was replaced with γ-butyrolactone and then concentrated to obtain a polyimide having an imidation ratio of about 93% (b-IPS6). 2,300 g of a solution containing 15 wt% was obtained. A small amount of this solution was taken, and the viscosity measured as a solution having a polyimide concentration of 10% by weight by adding γ-butyrolactone was 41 mPa · s.
When this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

<Preparation and Evaluation of TN Type Liquid Crystal Alignment Agent>
Example TN-1
(I) Preparation of Liquid Crystal Alignment Agent Equivalent to 80 parts by weight in terms of polyamic acid (A-TN1) in a solution containing the polyamic acid (A-TN1) obtained in Synthesis Example A-TN1 as a specific polymer And the amount corresponding to 20 parts by weight in terms of the polyimide (b-TN2) of the solution containing the polyimide (b-TN2) obtained in Synthesis Example b-TN2 as the other polymer. N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (BL), and butyl cellosolve (BC) are added thereto, and the final solvent composition is NMP: BL: BC = 17: 71: 12 (weight ratio). In addition, 2 parts by weight of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane was added as an epoxy compound to prepare a solution having a solid content concentration of 3.5 wt. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 1 μm.

(II) Evaluation of liquid crystal aligning agent (1) Manufacture of TN type liquid crystal cell With liquid crystal aligning agent prepared above, with transparent electrode made of ITO film using liquid crystal aligning film printer (Nissha Printing Co., Ltd.) After coating on the transparent electrode surface of the glass substrate and heating (pre-baking) on a hot plate at 80 ° C. for 1 minute to remove the solvent, heating (post-baking) on a hot plate at 200 ° C. for 10 minutes to obtain an average film A coating film having a thickness of 600 mm was formed.
The coating film is rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm to give liquid crystal alignment ability. did. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, followed by drying in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer edge of the surface having one liquid crystal alignment film of the pair of substrates, and the liquid crystal alignment film surfaces are relative to each other. Then, the adhesive was cured after being pressed against each other. Next, after filling nematic liquid crystal (MLC-6221 manufactured by Merck & Co., Inc.) between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. did.

(2) Evaluation of heat stability The durability against heat stress was evaluated using the voltage holding ratio as an index. As a voltage holding ratio measuring apparatus, model “VHR-1” manufactured by Toyo Corporation was used.
For the liquid crystal cell manufactured above, at 60 ° C., a voltage of 5 V was applied to the liquid crystal display element with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the voltage application release. Measured (initial voltage holding ratio VHR0).
Next, the liquid crystal display element after measurement of the voltage holding ratio before application of heat stress was left in an oven at 100 ° C. for 1,000 hours to apply heat stress, and then the voltage holding ratio was measured again in the same manner as described above. (Voltage holding ratio VHR1 after application of thermal stress).
Using the values of VHR0 and VHR1 measured above, the following formula (1)
ΔVHR = VHR0−VHR1 (1)
The voltage holding ratio difference ΔVHR before and after application of thermal stress was obtained. When this value is within 5%, it can be evaluated that the heat resistance stability is good.
The evaluation results are shown in Table 1.

Examples TN-2 and TN-3 and comparative examples tn-1 and tn-2
In the above Example TN-1, as the specific polymer and other polymer, solutions containing the types and amounts of polymers described in Table 1 were used. A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example TN-1, except that it was added as described.
The evaluation results are shown in Table 1.
“-” In Table 1 indicates that the polymer corresponding to the column was not used. In Comparative Example tn-1, two polymers were mixed and used as the other polymer.
Abbreviations of solvents in Table 1 have the following meanings, respectively.
NMP: N-methyl-2-pyrrolidone BL: γ-butyrolactone BC: Butyl cellosolve

<Preparation and Evaluation of VA Type Liquid Crystal Alignment Agent>
Example VA-1
(I) Preparation of Liquid Crystal Alignment Agent As a polymer, N-methyl-2-pyrrolidone and butyl cellosolve are added to a solution containing the polyimide (B-VA1) obtained in Synthesis Example B-VA1, and an epoxy compound is further added. 5 parts by weight of N, N, N ′, N′-tetraglycidyl-m-xylenediamine is added to 100 parts by weight of the polyimide used, and the mixture is sufficiently stirred. The solvent composition is N-methyl-2-pyrrolidone: Butyl cellosolve = 50: 50 (weight ratio), solid content concentration 3.5% by weight. The liquid crystal aligning agent was prepared by filtering using this filter with a pore size of 1 μm.
(II) Evaluation of liquid crystal aligning agent (1) Manufacture of VA type liquid crystal cell The liquid crystal aligning agent prepared above was applied with a spinner on a transparent conductive film made of an ITO film provided on one side of a 1 mm thick glass substrate. Then, prebaking was performed at 80 ° C. for 1 minute on a hot plate, and then post baking was performed at 210 ° C. for 30 minutes on the hot plate to form a coating film (liquid crystal alignment film) having a film thickness of 80 nm. This operation was repeated to obtain two (a pair) of substrates having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 um is applied to the outer edge of the surface having one liquid crystal alignment film of the pair of substrates, and each liquid crystal alignment film is relatively opposed to the pair of substrates. Then, the adhesive was cured after being pressed against each other. Next, after filling negative liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) between the substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell.
(2) Evaluation of heat stability The heat resistance stability was evaluated in the same manner as in Example TN-1 using the liquid crystal cell produced above. However, in the case of a VA liquid crystal cell, it can be evaluated that the heat resistance stability is good when the voltage holding ratio difference ΔVHR before and after application of thermal stress is within 2%.
The evaluation results are shown in Table 2.

Examples VA-2 to VA-6 and comparative examples va-1 and va-2
In Example VA-1, a liquid crystal aligning agent was prepared and evaluated in the same manner as in Example VA-1, except that solutions containing the polymers shown in Table 2 were used as the polymers.
The evaluation results are shown in Table 2.
“-” In Table 2 indicates that the polymer corresponding to the column was not used.
Abbreviations of solvents in Table 2 are the same as in Table 1.

<Preparation and Evaluation of IPS Liquid Crystal Alignment Agent>
Example IPS-1
(I) Preparation of liquid crystal aligning agent As a polymer, N-methyl-2-pyrrolidone and butyl cellosolve are added as a solvent to a solution containing the polyamic acid (A-IPS1) obtained in Synthesis Example A-IPS1. As an epoxy compound, 5 parts by weight of N, N, N ′, N′-tetraglycidyl-m-xylenediamine is added to 100 parts by weight of the polyamic acid used, and the mixture is sufficiently stirred. 2-pyrrolidone: butyl cellosolve = 80: 20 (weight ratio), and a solid content concentration of 3.5% by weight was obtained. The liquid crystal aligning agent was prepared by filtering using this filter with a pore size of 1 μm.
(II) Evaluation of liquid crystal aligning agent (1) Manufacture of liquid crystal cell A liquid crystal cell was manufactured in the same manner as in Example TN-1 except that the liquid crystal aligning agent prepared above was used, and the heat stability was evaluated. went.
The evaluation results are shown in Table 3.
Although the liquid crystal cell manufactured here is a TN liquid crystal cell, the present inventors have empirically confirmed that a TN liquid crystal cell can be used as a sample for evaluating the heat stability of an IPS liquid crystal cell. Have confirmed.

Examples IPS-2 to IPS-5 and comparative examples ips-1 to ips-3
In Example IPS-1, a liquid crystal aligning agent was prepared and evaluated in the same manner as in Example IPS-1, except that the polymers each containing a polymer listed in Table 3 were used.
The evaluation results are shown in Table 3.
Examples IPS-6-9 and comparative examples ips-4 and ips-5
In Example IPS-1, a solution containing each of the polymers shown in Table 3 was used as a polymer, and N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (BL) and butyl cellosolve (BC) were used as solvents. In the same manner as in Example IPS-1, except that each of these solvents was added so that the final solvent composition was NMP: BL: BC = 10: 70: 20 (weight ratio). An alignment agent was prepared and evaluated.
The evaluation results are shown in Table 3.
“-” In Table 3 indicates that the polymer corresponding to the column was not used.
Abbreviations of solvents in Table 3 are the same as those in Table 1.

Claims (3)

A liquid crystal aligning agent comprising a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, and at least one polymer selected from the group consisting of polyimides formed by dehydrating and ring-closing the polyamic acid,
The tetracarboxylic dianhydride is
At least one selected from the group consisting of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride, all tetracarboxylic dianhydrides der those containing 5 to 80 mol% with respect to is,
The diamine is
(I) It consists of 100 mol% of the following specific diamine 1 or contains 50 mol% or more of the following specific diamine 1 and 30 mol% or less of the following specific diamine 2 or
(Ii) The following specific diamine 1 20 to 97 mol% and the following specific diamine 2 3 to 80 mol%,
The specific diamine 1 is p-phenylenediamine, 3,5-diaminobenzoic acid, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 2,2′-dimethyl-4,4′-diaminobiphenyl, At least selected from the group consisting of 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-diaminodiphenylamine and 4,4 ′-(m-phenylenediisopropylidene) dianiline 1 type, and the specific diamine 2 is cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2, 4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, 3,5-diaminobenzoic acid co Suteniru, 3,5-diaminobenzoic acid Ranosutaniru, 3,6-bis (4-benzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane and the following formula (A-1):

(In the formula (A-1), ^{X I} is an alkylene group having 1 to 3 carbon ^atoms, * ^-O-, * -COO- or ^* -OCO- (where bond marked with "*" is diaminophenyl group And a is 0 or 1, b is an integer of 0 to 2, and c is an integer of 1 to 20.)
Is at least one selected from the group consisting of compounds represented by:
And
As a solvent, characterized that you containing a mixture or N- methyl-2-pyrrolidone and mixtures of ethylene glycol -n- butyl ether and γ- butyrolactone N- methyl-2-pyrrolidone and ethylene glycol -n- butyl ether The liquid crystal aligning agent (however, the polyamic acid in which 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride occupies 40 to 80 mol% of all tetracarboxylic dianhydrides alone is used as the polymer. Excluding liquid crystal aligning agent contained). The tetracarboxylic dianhydride is
1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2 , 5-Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2) , 5-Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(Tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5 , 6-Tricarboxy-2-carbo Cymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride and 4, 2. The composition according to claim 1, further comprising at least one selected from the group consisting of 9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone. Liquid crystal aligning agent. The liquid crystal aligning agent as described in any one of Claims 1-2 which further contains the compound which has at least 1 epoxy group in a molecule | numerator.