WO2016052714A1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element using same - Google Patents

Abstract

A liquid crystal aligning agent which contains at least one polymer selected from among polyamic acids, which are obtained using a tetracarboxylic acid dianhydride component containing an aromatic tetracarboxylic acid dianhydride and a diamine component containing a diamine represented by formula (1), and polyimides which are obtained by imidizing the polyamic acids. In the formula, R₁ represents a hydrogen atom or a monovalent organic group; Q₁ represents an alkylene group having 1-5 carbon atoms; Cy represents a divalent group that is an aliphatic heterocyclic ring composed of azetidine, pyrrolidine, piperidine or hexamethyleneimine, and a substituent may be bonded to a ring portion thereof; each of R₂ and R₃ represents a monovalent organic group; and each of q and r independently represents an integer of 0-4. In this connection, in cases where the total of q or r is 2 or more, each one of the plurality of R₂ moieties or R₃ moieties independently represents a monovalent organic group.

Description

Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element using the same

The present invention relates to a liquid crystal aligning agent used for a liquid crystal display element, a liquid crystal alignment film, and a liquid crystal display element using the same.

Liquid crystal display elements used for liquid crystal televisions, liquid crystal displays, and the like are usually provided with a liquid crystal alignment film for controlling the alignment state of the liquid crystals. Conventionally, as the liquid crystal alignment film, a polyimide-based liquid crystal alignment film obtained by applying a liquid crystal alignment agent mainly composed of a polyimide precursor such as polyamic acid (polyamic acid) or a solution of soluble polyimide to a glass substrate or the like and baking it is mainly used. It is used.

As liquid crystal display elements have become higher in definition, liquid crystal alignment films have high liquid crystal alignment characteristics and stable pretilt angles in addition to the demands for suppressing the decrease in contrast and reducing the afterimage phenomenon. Characteristics such as a voltage holding ratio, suppression of an afterimage generated by AC driving, a small residual charge when a DC voltage is applied, and / or an early relaxation of a residual charge accumulated by a DC voltage are becoming increasingly important.

Various proposals have been made for polyimide-based liquid crystal alignment films in order to meet the above requirements. For example, as a liquid crystal alignment film having a short time until an afterimage generated by a direct current voltage disappears, a liquid crystal alignment agent containing a tertiary amine having a specific structure in addition to polyamic acid or imide group-containing polyamic acid (for example, Patent Document 1), and those using a liquid crystal aligning agent containing a soluble polyimide using a specific diamine compound having a pyridine skeleton as a raw material have been proposed (for example, see Patent Document 2). In addition to polyamic acid and its imidized polymer, it contains one carboxylic acid group in the molecule as a liquid crystal alignment film with a high voltage holding ratio and a short time until the afterimage generated by direct current voltage disappears. Using a liquid crystal aligning agent containing a very small amount of a compound selected from a compound containing one carboxylic anhydride group in the molecule and a compound containing one tertiary amino group in the molecule ( For example, see Patent Document 3).

In addition, a tetracarboxylic acid having a specific structure of tetracarboxylic dianhydride and cyclobutane as a liquid crystal alignment film having excellent liquid crystal alignment, high voltage holding ratio, low afterimage, excellent reliability, and high pretilt angle Known is a liquid crystal alignment agent containing a polyamic acid obtained from a dianhydride and a specific diamine compound or an imidized polymer thereof (for example, see Patent Document 4). In addition, as a method of suppressing an afterimage caused by alternating current driving in a liquid crystal display element of a lateral electric field driving method, a method of using a specific liquid crystal alignment film that has good liquid crystal alignment and large interaction with liquid crystal molecules (patent) Document 5) has been proposed.

However, in recent years, large-screen and high-definition liquid crystal televisions are mainly used, and the demand for afterimages has become more severe, and characteristics that can withstand long-term use in harsh usage environments are required. At the same time, liquid crystal alignment films to be used are required to have higher reliability than conventional liquid crystal alignment films. Not only the initial characteristics of the liquid crystal alignment films are good, but also, for example, they are longer at high temperatures. There is a need to maintain good properties even after time exposure.

On the other hand, as a polymer component constituting a polyimide-based liquid crystal aligning agent, polyamic acid ester is excellent in liquid crystal alignment stability and reliability because it does not cause a decrease in molecular weight due to heat treatment when imidizing it. Has been reported (see Patent Document 6). Since polyamic acid esters generally have problems such as high volume resistivity and a large amount of residual charge when a DC voltage is applied, a liquid crystal aligning agent blended with polyamic acid esters and polyamic acids excellent in electrical characteristics Is disclosed (see Patent Document 7).

JP-A-9-316200 JP-A-10-104633 JP-A-8-76128 Japanese Patent Laid-Open No. 9-138414 JP 11-38415 A JP 2003-26918 A WO2011 / 158080

As described above, liquid crystal aligning agents corresponding to various requirements have been disclosed, but recently new problems have arisen.
In recent liquid crystal display elements, a design in which an effective pixel area is larger than a frame area is mainstream as compared with a conventional liquid crystal display element. For this reason, when the seal component applied in the frame region is eluted in the liquid crystal, it diffuses to the effective pixel region, causing a display defect. In order to solve this problem, it is required that the afterimage characteristics do not change even when the seal component is eluted in the liquid crystal.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have excellently satisfied the above-mentioned problems by using a tetracarboxylic dianhydride having a specific structure and a diamine compound having a specific structure. The present inventors have found that a liquid crystal alignment film exhibiting characteristics can be obtained, thereby completing the present invention. The present invention is based on this finding and has the following gist.
1. Of polyamic acid obtained using a tetracarboxylic dianhydride component containing an aromatic tetracarboxylic dianhydride and a diamine component containing a diamine of the following formula (1), and a polyimide obtained by imidizing it A liquid crystal aligning agent containing at least one polymer.

R ₁ represents hydrogen or a monovalent organic group, Q ₁ represents an alkylene having 1 to 5 carbon atoms, and Cy represents a divalent heterocyclic ring composed of azetidine, pyrrolidine, piperidine and hexamethyleneimine. A substituent may be bonded to these ring portions, R ₂ and R ₃ are monovalent organic groups, and q and r are each independently an integer of 0 to 4. However, when the sum of q or r is 2 or more, the plurality of R ₂ and R ₃ independently have the above definition.
2. R ₁ is an alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or a thermally leaving group that is replaced with a hydrogen atom by heat, and R ₂ and R ₃ are each independently a hydrogen atom, a methyl group, or a trifluoromethyl group. 2. The liquid crystal aligning agent according to 1, which is a cyano group or a methoxy group.
3. 3. The liquid crystal aligning agent according to 1 or 2, wherein R ₁ is a linear alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or a tert-butoxycarbonyl group, and Cy is a pyrrolidine ring or a piperidine ring.
4). The liquid crystal aligning agent as described in any one of 1-3 containing the diamine compound represented by following General formula (2).

In the formula (2), R ₁ is a hydrogen atom, a methyl group, or a tert-butoxycarbonyl group, R ₂ is a hydrogen atom or a methyl group, and Q ₁ is a linear alkylene having 1 to 5 carbon atoms.
5. The liquid crystal aligning agent as described in any one of 1-4 whose aromatic tetracarboxylic dianhydride is 20 mol% or more of all the tetracarboxylic dianhydrides components.
6). 6. The liquid crystal aligning agent according to any one of 1 to 5, wherein the aromatic tetracarboxylic dianhydride is pyromellitic dianhydride.
7). The liquid crystal aligning agent as described in any one of 1-6 whose diamine of the said Formula (1) is 30 mol% or more with respect to aromatic tetracarboxylic dianhydride.
The liquid crystal aligning film obtained using the liquid crystal aligning agent as described in any one of 8.1 to 7.
A liquid crystal display device comprising the liquid crystal alignment film according to 9.8.

According to the present invention, the accumulated DC charge amount is not easily changed even when the seal component is contaminated in the liquid crystal without deteriorating the liquid crystal alignment property or the accumulated charge relaxation property, that is, the display defect occurs due to the influence of the seal component. A liquid crystal alignment film that is difficult to form and a liquid crystal display element using the same are provided.

The present invention will be described in detail below.

The liquid crystal aligning agent of this invention is a polyimide precursor obtained by using the tetracarboxylic dianhydride component containing aromatic tetracarboxylic dianhydride, and the diamine component containing the diamine of said Formula (1), and it It is a liquid crystal aligning agent containing at least 1 type of polymer among the polyimides obtained by imidizing. Hereinafter, each component requirement is explained in full detail.

<Aromatic tetracarboxylic dianhydride>
An aromatic tetracarboxylic dianhydride is used for the liquid crystal aligning agent of the present invention. These may be used alone or in combination of two or more. Examples of the tetracarboxylic acid that is a raw material for obtaining an aromatic tetracarboxylic dianhydride include pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid. 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3 ′, 4,4′- Biphenyltetracarboxylic acid, 2,3,3 ′, 4-biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3 4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3 , 3-hexafluoro-2,2′-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, , 3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3,4-dicarboxyphenyl) pyridine, and the like. From the viewpoint of reducing liquid crystal orientation and afterimage, pyromellitic acid, 2 , 3,6,7-naphthalenetetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyl) Phenyl) ether, and pyromellitic acid and 3,3 ′, 4,4′-biphenyltetracarboxylic acid are more preferable.

The aromatic tetracarboxylic dianhydride is preferably 20 mol% or more of the total tetracarboxylic dianhydride component used for the synthesis of the polymer contained in the liquid crystal aligning agent of the present invention.

<Other tetracarboxylic dianhydrides>
In synthesizing the polyamic acid used in the liquid crystal aligning agent of the present invention, other tetracarboxylic dianhydrides may be used in addition to the above aromatic tetracarboxylic dianhydrides, as long as the effects of the present invention are not impaired. I can do it. Specific examples of other tetracarboxylic dianhydrides are listed below.

Examples of the tetracarboxylic acid that is a raw material for obtaining the aliphatic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2, 3,4,5-tetrahydrofurantetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 1,2,4,5-pentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, bicyclo [3,3,0] octane-2,4 6,8-tetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 1,2,4,5- Chlohexanetetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, bicyclo [3,3,0] Examples include octane-2,4,6,8-tetracarboxylic acid, and 1,2,3,4-cyclobutanetetracarboxylic acid or derivatives thereof are preferable from the viewpoint of liquid crystal alignment. Further, from the viewpoint of a low pretilt angle necessary for a liquid crystal display element for driving a horizontal electric field, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid, 1,2,3,4 -Butanetetracarboxylic acid and 1,2,4,5-pentanetetracarboxylic acid are preferred.

Therefore, dianhydrides of 1,2,3,4-cyclobutanetetracarboxylic acid or derivatives thereof and bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid, 1,2, When at least one tetracarboxylic dianhydride selected from 3,4-butanetetracarboxylic acid and 1,2,4,5-pentanetetracarboxylic dianhydride is used in combination, the liquid crystal orientation is low and low This is preferable because both pretilt angles can be achieved.

<Specific diamine>
The specific diamine used in synthesizing the polyamic acid used in the liquid crystal aligning agent of the present invention is represented by the following formula (1).

R ₁ represents hydrogen or a monovalent organic group, preferably a hydrogen atom, a linear alkyl group having 1 to 3 carbon atoms, or a protecting group that undergoes elimination reaction by heat to replace a hydrogen atom, more preferably hydrogen. It is a protecting group that undergoes elimination reaction by an atom, a methyl group or heat and replaces a hydrogen atom.

The protecting group that undergoes elimination reaction by heat and is replaced with a hydrogen atom is a protecting group that does not desorb at room temperature, and preferably desorbs with heat of 80 ° C. or more, from the viewpoint of the storage stability of the liquid crystal aligning agent. Preferably, it is a protecting group capable of leaving by heat at 100 ° C. or higher. Examples of such protecting groups include 1,1-dimethyl-2-chloroethoxycarbonyl group, 1,1-dimethyl-2-cyanoethoxycarbonyl group, and tert-butoxycarbonyl group, preferably tert-butoxycarbonyl group. Groups.

Q ₁ represents an alkylene group having 1 to 5 carbon atoms, and is preferably a linear alkylene having 1 to 5 carbon atoms for the convenience of synthesis.
Cy is a divalent group representing an aliphatic heterocyclic ring composed of azetidine, pyrrolidine, piperidine, and hexamethyleneimine, and azetidine, pyrrolidine, and piperidine are preferable from the viewpoint of ease of synthesis. In addition, a substituent may be bonded to these ring portions.

R ₂ and R ₃ are monovalent organic groups, and q and r are each independently an integer of 0 to 4. However, when the sum of q or r is 2 or more, the plurality of R ₂ and R ₃ independently have the above definition. Preferably, R ₂ and R ₃ are each independently a hydrogen atom, a methyl group, a trifluoromethyl group, a cyano group, or a methoxy group, and are preferably a hydrogen atom or a methyl group for ease of synthesis. More preferred. In addition, the bonding position of the amino group in the benzene ring constituting the diamine compound is not limited, but each amino group is bonded to the nitrogen atom on Cy at the 3-position or 4-position, and Q ₁ and R ₁ are bonded. It is preferably in the 3rd or 4th position with respect to the nitrogen atom, in the 4th position with respect to the nitrogen atom on Cy and in the 4th position with respect to the nitrogen atom to which Q ₁ and R ₁ are bonded It is more preferable.

The diamine compound represented by the above formula (1) of the present invention preferably has the structure of the following formula (2).

In the formula (2), R ₁ is a hydrogen atom, a methyl group, or a tert-butoxycarbonyl group. R ₂ is a hydrogen atom or a methyl group. Q ₁ is a linear alkylene having 1 to 5 carbon atoms.

Specific examples represented by the above formula (2) include those represented by the following formulas (2-1) to (2-10), for example. In the following formula, Boc represents a tert-butoxycarbonyl group.

The specific diamine of the above formula (1) used in the liquid crystal aligning agent of the present invention is preferably 30 mol% or more based on the aromatic tetracarboxylic dianhydride used in the liquid crystal aligning agent of the present invention.

The method for producing the diamine compound represented by the formula (1) of the present invention is not particularly limited, but as a preferred method, it can be produced by the following production method [1] or [2].

Manufacturing method [1]
The following dinitro compound (3-3) is produced by reacting 2 equivalents or more of the nitro compound (3-1) with the aliphatic amine compound (3-2). Introducing a monovalent organic group comprising R ₁ and if necessary, it is possible to obtain the desired diamine by subsequent reduction of the nitro group. These nitro compounds (3-1) and aliphatic amine compounds (3-2) can be easily obtained as commercial products.

In (3-1), X represents a halogen atom and represents an F, Cl, Br or I atom. R ₂ is a monovalent organic group, q is an integer of 0 to 4, and when q is 2 or more, the plurality of R ₂ independently have the above definition.

If X is F or Cl and the NO ₂ group is at the 2-position or 4-position relative to X, the aryl halide is reacted with an aliphatic amine compound in the presence of a suitable base, and dinitro The body (3-3) can be obtained. Examples of the base used include inorganic bases such as sodium hydrogen carbonate, potassium hydrogen carbonate, potassium phosphate, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, diisopropyl Amines such as ethylamine, pyridine, quinoline and collidine, and bases such as sodium hydride and potassium hydride can be used.

Regarding the solvent, any solvent that does not react with the raw material can be used, and an aprotic polar organic solvent (DMF, DMSO, DMAc, NMP, etc.), ethers (Et ₂ O, i-Pr ₂ O, TBME, CPME, THF, dioxane, etc.), aliphatic hydrocarbons (pentane, hexane, heptane, petroleum ether, etc.), aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene, tetralin, etc.) Halogenated hydrocarbons (chloroform, dichloromethane, carbon tetrachloride, dichloroethane, etc.), lower fatty acid esters (methyl acetate, ethyl acetate, butyl acetate, methyl propionate, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.) ) Can be used. These solvents can be appropriately selected in consideration of the ease of reaction and the like. In this case, the above solvents can be used alone or in combination of two or more. In some cases, an appropriate dehydrating agent or desiccant can be used as a non-aqueous solvent. The reaction temperature can be selected in the range from −100 ° C. to the boiling point of the solvent to be used, but it is preferably in the range of −50 to 150 ° C. The reaction time can be arbitrarily selected within the range of 0.1 to 1000 hours. The product may be purified by recrystallization, distillation, silica gel column chromatography or the like.

If X is Br or I, the NO ₂ group may be 2-position, 3-position or 4-position relative to X, and a CN cross-coupling reaction is used in the presence of a suitable metal catalyst, ligand and base. In this way, a dinitro compound can be obtained. Examples of metal catalysts include palladium acetate, palladium chloride, palladium chloride-acetonitrile complex, palladium-activated carbon, bis (dibenzylideneacetone) palladium, tris (dibenzylideneacetone) dipalladium, bis (acetonitrile) dichloropalladium, bis (benzo Nitrile) dichloropalladium, CuCl, CuBr, CuI, CuCN, and the like, but are not limited thereto. Examples of ligands include triphenylphosphine, tri-o-tolylphosphine, diphenylmethylphosphine, phenyldimethylphosphine, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane 1,4-bis (diphenylphosphino) butane, 1,1′-bis (diphenylphosphino) ferrocene, trimethyl phosphite, triethyl phosphite, triphenyl phosphite, tri-tert-butylphosphine and the like. However, it is not limited to these. As examples of the base, the aforementioned bases can be used. The reaction solvent and reaction temperature are the same as described above. The product may be purified by recrystallization, distillation, silica gel column chromatography or the like.

In the formula (4), a monovalent organic group composed of R ₁ may be introduced into the dinitro body (3-3) as necessary.

In introducing R ₁ , any compound capable of reacting with amines may be used, and examples thereof include acid halides, acid anhydrides, isocyanates, epoxies, oxetanes, halogenated aryls, and halogenated alkyls. In addition, alcohols in which a hydroxyl group of alcohol is substituted with a leaving group such as OMs, OTf, OTs, or the like can be used.

The method for introducing a monovalent organic group composed of R ₁ into the NH group is not particularly limited, and examples thereof include a method of reacting an acid halide in the presence of a suitable base. Examples of acid halides include acetyl chloride, propionic acid chloride, methyl chloroformate, ethyl chloroformate, n-propyl chloroformate, i-propyl chloroformate, n-butyl chloroformate, i-butyl chloroformate, t-chloroformate. Examples include butyl, benzyl chloroformate, and 9-fluorenyl chloroformate. As examples of the base, the aforementioned bases can be used. The reaction solvent and reaction temperature are the same as described above.

R ₁ may be introduced by reacting an acid anhydride with an NH group. Examples of acid anhydrides include acetic anhydride, propionic anhydride, dimethyl dicarbonate, diethyl dicarbonate, di-tertiary butyl dicarbonate. And dibenzyl dicarbonate. A catalyst may be added to promote the reaction, and pyridine, collidine, N, N-dimethyl-4-aminopyridine, etc. may be used. The amount of the catalyst is 0.0001 mol to 1 mol with respect to the amount of use of (3-3). The reaction solvent and reaction temperature are the same as described above.

R ₁ may be introduced by reacting an isocyanate with an NH group. Examples of the isocyanate include methyl isocyanate, ethyl isocyanate, n-propyl isocyanate, and phenyl isocyanate. The reaction solvent and reaction temperature are the same as described above.

R ₁ may be introduced by reacting an NH group with an epoxy compound or oxetane compound. Examples of the epoxy or oxetane include ethylene oxide, propylene oxide, 1,2-butylene oxide, trimethylene oxide, and the like. Can be mentioned. The reaction solvent and reaction temperature are the same as described above.

The NH group may be reacted with aryl halides in the presence of a metal catalyst, a ligand and a base to introduce R _1, and examples of aryl halides include iodobenzene, bromobenzene, chlorobenzene and the like. . Examples of metal catalysts include palladium acetate, palladium chloride, palladium chloride-acetonitrile complex, palladium-activated carbon, bis (dibenzylideneacetone) palladium, tris (dibenzylideneacetone) dipalladium, bis (acetonitrile) dichloropalladium, bis (benzo Nitrile) dichloropalladium, CuCl, CuBr, CuI, CuCN and the like, but are not limited thereto. Examples of ligands include triphenylphosphine, tri-o-tolylphosphine, diphenylmethylphosphine, phenyldimethylphosphine, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane 1,4-bis (diphenylphosphino) butane, 1,1′-bis (diphenylphosphino) ferrocene, trimethyl phosphite, triethyl phosphite, triphenyl phosphite, tri-tert-butylphosphine and the like. However, it is not limited to these. As examples of the base, the aforementioned bases can be used. The reaction solvent and reaction temperature are the same as described above.

R ₁ may be introduced by reacting an alcohol in which the hydroxyl group of the alcohol is substituted with a leaving group such as OMs, OTf, OTs in the presence of a suitable base in the NH group. Examples of alcohols include methanol, Ethanol, 1-propanol and the like can be mentioned, and by reacting these alcohols with methanesulfonyl chloride, trifluoromethanesulfonyl chloride, paratoluenesulfonic acid chloride, etc., the leaving groups such as OMs, OTf, OTs and the like are substituted. Alcohol can be obtained. As examples of the base, the aforementioned bases can be used. The reaction solvent and reaction temperature are the same as described above.

R ₁ may be introduced by reacting an alkyl halide with NH group in the presence of a suitable base. Examples of alkyl halides include methyl iodide, ethyl iodide, n-propyl iodide, bromide. Examples include methyl, ethyl bromide, n-propyl bromide and the like. Examples of the base include metal alkoxides such as potassium tert-butoxide and sodium tert-butoxide in addition to the above-mentioned bases. The reaction solvent and reaction temperature are the same as described above.

Next, in formula (5), the nitro group of the obtained dinitro compound (4-1) can be reduced to obtain the target diamine compound (5-1). For this purpose, palladium carbon powder, platinum carbon powder or the like can be used, which is carried out under a hydrogen atmosphere, at normal pressure, or under pressurized conditions.

Further, reduction of the nitro group may be performed using a metal such as Fe, Sn, Zn, or a metal salt thereof together with a proton source. Metals and metal salts may be used alone or jointly.
As the proton source, acids such as hydrochloric acid, ammonium salts such as ammonium chloride, and protic solvents such as methanol and ethanol can be used.

The solvent is not particularly limited as long as it can withstand an environment under a reducing atmosphere, such as an aprotic polar organic solvent (DMF, DMSO, DMAc, NMP, etc.), ethers (Et ₂ O, i-Pr ₂ O, TBME, CPME, THF, dioxane, etc.), aliphatic hydrocarbons (pentane, hexane, heptane, petroleum ether, etc.), aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene, tetralin, etc.) Lower fatty acid esters (methyl acetate, ethyl acetate, butyl acetate, methyl propionate, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.), alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1 -Butanol, etc.) that can be used , By considering the likelihood of occurrence of the reaction can be appropriately selected, in this case, the solvents may be used singly or in combination of two or more thereof. In some cases, an appropriate dehydrating agent or desiccant can be used as a non-aqueous solvent. The reaction temperature can be selected in the range from −100 ° C. to the boiling point of the solvent to be used, but it is preferably in the range of −50 to 150 ° C. The reaction time can be arbitrarily selected within the range of 0.1 to 1000 hours. The product may be purified by recrystallization, distillation, silica gel column chromatography, activated carbon or the like.

Manufacturing method [2]
By reacting the nitro compound (3-1 or 6-1) with the aliphatic amine compound (6-2) protected with a protecting group, the intermediate (6-3 or 6-4) is obtained. obtain. After deprotection, the following dinitro compound (8-1 or 8-2) is obtained by reacting the nitro compound (3-1 or 6-1). Further, if necessary, a target diamine can be obtained by introducing a monovalent organic group into R ₁ by the same method as in the production method [1] and then reducing the nitro group.

These dinitro compounds (6-1) and amine compounds (6-2) protected with a protecting group can be easily obtained as commercial products.

In formula (6), X, R ₂ and q are as described above, R ₃ is a monovalent organic group, r is an integer of 0 to 4, and when r is 2 or more, a plurality of R ₃ independently has the above definition.

Pro represents a protecting group such as acetyl group, trifluoroacetyl group, pivaloyl group, tert-butoxycarbonyl group, ethoxycarbonyl group, isopropoxycarbonyl group, 2,2,2-trichloroethoxycarbonyl group, benzyloxycarbonyl group, trimethylsilyl. Group, triethylsilyl group, dimethylphenylsilyl group, tert-butyldimethylsilyl group, tert-butyldiethylsilyl group, 9-fluorenylmethyloxycarbonyl group, phthaloyl group, allyloxycarbonyl group, p-toluenesulfonyl group, o -Represents a nitrobenzenesulfonyl group or the like.

The nitro compound (6-3 or 6-4) is synthesized by using the nitro compound (3-1 or 6-1) in an amount of 1 equivalent or more, and the production method [1] It can be implemented in a similar manner. It is desirable that the protecting group is not deprotected by basic conditions, and a tert-butoxycarbonyl group is desirable from the viewpoint of ease of deprotection after reaction and availability.

In formula (7), intermediate (7-1 or 7-2) can be obtained by deprotecting the nitro compound (6-3 or 6-4).

The method for deprotecting the protecting group is not particularly limited, but the desired product can be obtained by neutralization after hydrolysis in the presence of an acid or a base. Examples of the acid used include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and hydrobromic acid, and organic acids such as formic acid, acetic acid, oxalic acid, and trifluoroacetic acid. Examples of the base used include hydroxyl acid Sodium, sodium bicarbonate, potassium bicarbonate, potassium phosphate, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate and other inorganic bases, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, diisopropylethylamine, pyridine, quinoline Organic amines such as collidine may also be used. Alternatively, deprotection may be performed using a Lewis acid compound such as aluminum chloride or a trifluoroborane-diethyl ether complex. However, the debenzylation reaction in a hydrogen atmosphere is not preferable because reduction of an aromatic nitro group to an amine occurs.

With respect to the solvent, any solvent that does not hinder hydrolysis can be used, such as an aprotic polar organic solvent (DMF, DMSO, DMAc, NMP, etc.), ethers (Et ₂ O, i-Pr ₂ O, TBME). , CPME, THF, dioxane, etc.), aliphatic hydrocarbons (pentane, hexane, heptane, petroleum ether, etc.), aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene, tetralin, etc.) ), Halogenated hydrocarbons (chloroform, dichloromethane, carbon tetrachloride, dichloroethane, etc.), lower fatty acid esters (methyl acetate, ethyl acetate, butyl acetate, methyl propionate, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.) Etc.), alcohols (methanol) , Ethanol, 1-propanol, 2-propanol, 1-butanol, etc.), or water can be used. These solvents can be appropriately selected in consideration of the ease of reaction and the like. In this case, the above solvents can be used alone or in combination of two or more. In consideration of the use of a Lewis acid, etc., it can also be used as a non-aqueous solvent using an appropriate dehydrating agent or drying agent. The reaction temperature can be selected in the range from −100 ° C. to the boiling point of the solvent to be used, but it is preferably in the range of −50 to 150 ° C. The reaction time can be arbitrarily selected within the range of 0.1 to 1000 hours. The product may be purified by recrystallization, distillation, silica gel column chromatography or the like.

Using 1 equivalent or more of the nitro compound (3-1 or 6-1) to the deprotected nitro compound (7-1 or 7-2), the above formula (3) ) To obtain the dinitro compound (8-1 or 8-2).

The method for introducing R ₁ into the obtained dinitro compound (8-1 or 8-2) as necessary may be the same reaction conditions as in the above formula (4), and then reducing the nitro group. The desired diamine can be obtained. What is necessary is just to implement the reduction | restoration method of a dinitro body on reaction conditions similar to the said Formula (5).

<Other diamines>
In synthesizing the polyamic acid used in the liquid crystal aligning agent of the present invention, other diamine compounds can be used in addition to the specific diamine as long as the effects of the present invention are not impaired. Specific examples of other diamine compounds are listed below.

p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2, 5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4 , 6-diaminoresorcinol, 4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dihydroxy -4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, , 3′-trifluoromethyl-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2′-diaminobiphenyl, 2,3′-diaminobiphenyl, 4, 4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3 ' -Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis (4- Aminophenyl) silane, bis (3-aminophenyl) Nyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4′-thiodianiline, 3,3′-thiodianiline, 4,4′-diaminodiphenylamine, 3, 3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4 ' -Diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diaminobenzophenone, 2,3'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1, 8-Diaminonaphthalene, 2,5-diaminonaphtha 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (3-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, , 3-bis (3-aminophenyl) propane, 1,4-bis (4-aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3,5-diethyl-4-aminophenyl) ) Methane, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4- Aminophenethyl) urea, N-methyl-2- (4-aminophenyl) ethylamine, 4,4 ′-[1,4-phenylenebis (methylene)] dianiline, 4,4 ′-[1,3-phenyl Nylenebis (methylene)] dianiline, 3,4 ′-[1,4-phenylene dbis (methylene)] dianiline, 3,4 ′-[1,3-phenylenebis (methylene)] dianiline, 3,3 ′-[ 1,4-phenylenebis (methylene)] dianiline, 3,3 ′-[1,3-phenylenebis (methylene)] dianiline, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4- Phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3-phenylenebis [(3-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4-aminobenzoate), 1, -Phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) isophthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamide), N, N ′-(1,3-phenylene) bis (4-aminobenzamide), N, N ′-(1,4-phenylene) Bis (3-aminobenzamide), N, N ′-(1,3-phenylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis ( 3-aminophenyl) terephthalamide, N, N′-bis (4-aminophenyl) isophthalamide, N, N′-bis (3-aminophenyl) Isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenyl sulfone, 2,2′-bis [4- (4-aminophenoxy) phenyl] propane, 2,2′-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2′-bis (4-aminophenyl) hexafluoropropane, 2,2′-bis (3-aminophenyl) hexa Fluoropropane, 2,2'-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2'-bis (4-aminophenyl) propane, 2,2'-bis (3-aminophenyl) propane 2,2′-bis (3-amino-4-methylphenyl) propane, bis (4-aminophenoxy) methane, 1,2-bis (4-a Nophenoxy) ethane, 1,2-bis (3-aminophenoxy) ethane, 1,3-bis (4-aminophenoxy) propane, 1,3-bis (3-aminophenoxy) propane, 1,4-bis ( 4-aminophenoxy) butane, 1,4-bis (3-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,5-bis (3-aminophenoxy) pentane, 1,6- Bis (4-aminophenoxy) hexane, 1,6-bis (3-aminophenoxy) hexane, 1,7- (4-aminophenoxy) heptane, 1,7- (3-aminophenoxy) heptane, 1, 8-bis (4-aminophenoxy) octane, 1,8-bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis ( -Aminophenoxy) nonane, 1,10- (4-aminophenoxy) decane, 1,10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) undecane, 1,11- (3-amino Phenoxy) undecane, 1,12- (4-aminophenoxy) dodecane, 1,12- (3-aminophenoxy) dodecane, bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, , 10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and the like. Among these, from the viewpoint of good orientation and the like, bis (4-aminophenoxy) methane, 1,2-bis (4-aminophenoxy) ethane, 1,3-bis (4-aminophenoxy) propane, 1,4 -Bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7- (4-aminophenoxy) heptane, , 8-bis (4-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,3-bis (4-aminophenethyl) urea N-methyl-2- (4-aminophenyl) ethylamine is preferably used.

The other diamine compounds mentioned above are of one type depending on characteristics such as volume resistivity, rubbing resistance, ion density characteristics, transmittance, liquid crystal alignment characteristics, voltage holding characteristics and accumulated charges when used as a liquid crystal alignment film. Alternatively, two or more types can be mixed and used.

<Synthesis of polyamic acid>
When the polyamic acid used in the liquid crystal aligning agent of the present invention is obtained by reaction of tetracarboxylic dianhydride and diamine, a method of mixing tetracarboxylic dianhydride and diamine in an organic solvent and reacting them is Convenient.

The organic solvent used in the above reaction is not particularly limited as long as the generated polyamic acid is soluble. Specific examples are N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethyl. Examples thereof include sulfoxide and γ-butyrolactone. These may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polyamic acid, it may be used by mixing with the above solvent as long as the produced polyamic acid does not precipitate. In addition, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the generated polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.

As a method of mixing the tetracarboxylic dianhydride component and the diamine component in an organic solvent, a solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride component is used as it is or in an organic solvent. A method of adding by dispersing or dissolving in a solvent, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, and a tetracarboxylic dianhydride component and a diamine component. The method of adding alternately etc. are mentioned, In this invention, any of these methods may be sufficient. Further, when the tetracarboxylic dianhydride component or the diamine component is composed of a plurality of types of compounds, the plurality of types of components may be reacted in a mixed state in advance or may be reacted individually and sequentially.

The temperature at which the tetracarboxylic dianhydride component and the diamine component are reacted in an organic solvent is usually 0 to 150 ° C., preferably 5 to 100 ° C., more preferably 10 to 80 ° C. When the temperature is higher, the polymerization reaction is completed earlier, but when it is too high, a high molecular weight polymer may not be obtained. The reaction can be carried out at any concentration, but if the concentration is too low, it is difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring is difficult. Therefore, it is preferably 1 to 50% by weight, more preferably 5 to 30% by weight. The initial reaction may be carried out at a high concentration, and then an organic solvent may be added.

The ratio of tetracarboxylic dianhydride component: diamine component used for the polymerization reaction of polyamic acid is preferably 1: 0.8 to 1.2 in terms of molar ratio. In addition, since the polyamic acid obtained with an excess of the diamine component may increase the coloration of the solution, if the coloration of the solution is a concern, the above ratio may be 1: 0.8 to 1. . Similar to the normal polycondensation reaction, the closer the molar ratio is to 1: 1, the higher the molecular weight of the polyamic acid obtained. If the molecular weight of the polyamic acid is too small, the strength of the coating film obtained therefrom may be insufficient. Conversely, if the molecular weight of the polyamic acid is too large, the solution viscosity when the liquid crystal aligning agent is used as the coating solution is low. It may become too high, and the workability at the time of coating film formation and the uniformity of a coating film may worsen.

The weight average molecular weight of such polyamic acid is preferably 5,000 to 300,000, more preferably 10,000 to 200,000, and the number average molecular weight is preferably 2,500 to 300,000. 150,000, more preferably 5,000 to 100,000.

If you do not want to include the solvent used for the polymerization of the polyamic acid in the liquid crystal aligning agent of the present invention, or if there are unreacted monomer components or impurities in the reaction solution and you want to remove them, the polyamic acid Perform precipitation recovery and purification. As the method, a method of adding the polyamic acid solution to a stirring poor solvent and recovering the precipitate is simple. Although it does not specifically limit as a poor solvent used for precipitation collection | recovery of polyamic acid, Methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene etc. can be illustrated. The polyamic acid precipitated by introducing it into a poor solvent can be recovered by filtration, washing and drying at room temperature or under reduced pressure at normal temperature or under reduced pressure. By further dissolving the powder in a good solvent and reprecipitating it 2 to 10 times, the polyamic acid can be purified. When the impurities cannot be removed by a single precipitation recovery operation, it is preferable to perform this purification step. In this case, it is preferable to use three or more kinds of poor solvents such as alcohols, ketones, and hydrocarbons as the poor solvent because the purification efficiency is further increased. The precipitation recovery and purification operations described above can be similarly performed during the synthesis of polyimide described later.

When the polyamic acid is partially or wholly imidized, the production method is not particularly limited, but the polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine may be imidized as it is in a solution. it can. At this time, in order to convert a part or all of the polyamic acid into polyimide, a method of dehydrating and ring-closing by heating or a method of chemically ring-closing using a known dehydration and ring-closing catalyst is employed. In the method by heating, an arbitrary temperature of 100 ° C. to 300 ° C., preferably 120 ° C. to 250 ° C. can be selected. In the method of chemically ring-closing, for example, pyridine, triethylamine and the like can be used in the presence of acetic anhydride, and the temperature at this time can be selected from -20 ° C to 200 ° C.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of this invention is a coating liquid for forming a liquid crystal aligning film, and is a solution which the resin component for forming a resin film melt | dissolved in the organic solvent. Here, the said resin component is a resin component containing at least 1 sort (s) among the above-mentioned polyamic acid and the polyimide obtained by imidating this. In that case, the content of the resin component is preferably 1% by mass to 20% by mass, more preferably 1.5% by mass to 15% by mass, and particularly preferably 2% by mass to 10% by mass.

In the liquid crystal aligning agent of the present invention, all of the resin components may be the polyamic acid of the present invention and a polyimide obtained by imidizing it, or other polymers may be mixed. . In that case, the content of the polymer other than the polyimide obtained by imidizing the polyamic acid of the present invention in the resin component is 0.5 mass% to 95 mass%, preferably 1 mass% to 90 mass%. It is.

Examples of such other polymer include polyamic acid of the present invention and polyamic acid other than polyimide obtained by imidizing it, and polyimide obtained by imidizing it.

The organic solvent used in the liquid crystal aligning agent of the present invention is not particularly limited as long as it is an organic solvent that dissolves the resin component. Specific examples are given below.

N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, Dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4 -Hydroxy-4-methyl-2-pentanone and the like. These may be used alone or in combination.

The liquid crystal aligning agent of the present invention may contain components other than those described above. Examples thereof include solvents and compounds that improve the film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, and compounds that improve the adhesion between the liquid crystal aligning film and the substrate.

Specific examples of solvents (poor solvents) that improve film thickness uniformity and surface smoothness include the following.

For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoacetate Isopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, di Tylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene , Propyl ether, dihexyl ether, 1-hexanol n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, 3- Methyl methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy- 2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether 2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n- Examples thereof include solvents having low surface tension such as butyl ester and isoamyl lactate.

These poor solvents may be used alone or in combination. When using the above solvent, it is preferable that it is 5 to 80 mass% of the whole solvent contained in a liquid crystal aligning agent, More preferably, it is 15 to 60 mass%.

Examples of compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) ), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.). The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds and epoxy group-containing compounds.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10- Riethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyl Trimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3- Aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxy Silane, 3-glycidoxypropylmethyl Ethoxysilane, 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, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl- m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N ′,-tetraglycidyl-4, 4′-diaminodiphe And nilmethane.

When using a compound that improves adhesion to the substrate, the amount used is preferably 0.1 to 30 parts by mass, more preferably 100 parts by mass of the resin component contained in the liquid crystal aligning agent. Is 1 to 20 parts by mass. If the amount used is less than 0.1 parts by mass, the effect of improving the adhesion cannot be expected, and if it exceeds 30 parts by mass, the orientation of the liquid crystal may deteriorate.

In addition to the above, the liquid crystal aligning agent of the present invention has a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film, as long as the effects of the present invention are not impaired. Further, a crosslinkable compound for the purpose of increasing the hardness and density of the liquid crystal alignment film may be added.

The liquid crystal aligning agent of the present invention obtained as described above can be filtered as necessary, applied to a substrate, dried and baked to form a coating film. By performing alignment treatment such as irradiation, it can be used as a liquid crystal alignment film.

At this time, the substrate to be used is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used, and an ITO electrode for driving a liquid crystal is formed. It is preferable to use a new substrate from the viewpoint of simplification of the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

Examples of the method for applying the liquid crystal aligning agent include spin coating, printing, and ink-jet methods, but from the viewpoint of productivity, the transfer printing method is widely used industrially. Are also preferably used.

The drying process after applying the liquid crystal aligning agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, a drying process is included. Is preferred. The drying is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coating film is not deformed by the conveyance of the substrate or the like. As a specific example, a method of drying on a hot plate at 50 to 150 ° C., preferably 80 to 120 ° C., for 0.5 to 30 minutes, preferably 1 to 5 minutes is employed.

The firing of the liquid crystal aligning agent can be performed at an arbitrary temperature of 100 to 350 ° C., preferably 150 to 300 ° C., more preferably 200 to 250 ° C. When the liquid crystal aligning agent contains a polyimide precursor, the conversion rate from the polyimide precursor to the polyimide varies depending on the baking temperature, but the liquid crystal aligning agent of the present invention does not necessarily need to be 100% imidized. However, baking is preferably performed at a temperature higher by 10 ° C. or more than the heat treatment temperature required for the liquid crystal cell manufacturing process, such as sealing agent curing.

If the thickness of the coating film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered, so that it is 5 to 300 nm, preferably 10 to 100 nm. It is.

<Liquid crystal display element>
The liquid crystal display element of the present invention is a liquid crystal display element obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then preparing a liquid crystal cell by a known method. To give an example of the production of a liquid crystal cell, a pair of substrates on which a liquid crystal alignment film is formed is usually sandwiched with a spacer of 1 to 30 μm, preferably 2 to 10 μm, and the rubbing direction is preferably 0 to 270 °. A method is generally used in which the angle is set at an arbitrary angle, the periphery is fixed with a sealant, and liquid crystal is injected and sealed. An existing rubbing apparatus can be used for the rubbing treatment for the liquid crystal alignment film. Examples of the material of the rubbing cloth at this time include cotton, rayon, and nylon. The method for enclosing the liquid crystal is not particularly limited, and examples thereof include a vacuum method for injecting liquid crystal after reducing the pressure inside the produced liquid crystal cell, and a dropping method for sealing after dropping the liquid crystal.

Thus, since the liquid crystal display element produced using the liquid crystal aligning agent of this invention is excellent in the orientation of a liquid crystal, alignment control power, and has the outstanding electrical property, it is a contrast fall or image sticking. A liquid crystal display device that is unlikely to occur can be obtained. Among these liquid crystal display elements, the liquid crystal display element is particularly preferably used for a horizontal electric field type liquid crystal display element in which seizure due to the alignment regulating force easily occurs.

Hereinafter, the present invention will be described more specifically with reference to examples. However, it is needless to say that the present invention is not construed as being limited to these examples.

X-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride
X-2: pyromellitic dianhydride
X-3: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride

Y-1: 1,3-bis (4-aminophenethyl) urea Y-2: 4- (2- (methylamino) ethyl) aniline Y-3: 4,4′-diaminodiphenylamine Y-4: bis (4 -Aminophenoxy) methane DA-1: a compound represented by the following structural formula

Each measurement method is shown below.

[viscosity]
In the synthesis example, the viscosity of the polyamic acid solution was an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), sample amount 1.1 mL, cone rotor TE-1 (1 ° 34 ′, R24), temperature 25 Measured at ° C.

[Solid content]
In the synthesis example, the solid content concentration of the polyamic acid solution was calculated as follows.

Aluminum cup with handle No. Approximately 1.1 g of the solution was weighed into 2 (manufactured by ASONE), heated in an oven DNF400 (manufactured by Yamato) at 200 ° C. for 2 hours, and then allowed to stand at room temperature for 5 minutes, and the weight of the solid content remaining in the aluminum cup was weighed. . The solid content concentration was calculated from the solid content weight and the original solution weight value.

[Molecular weight]
The molecular weight of the polyamic acid solution is measured by a GPC (room temperature gel permeation chromatography) apparatus, and is a number average molecular weight (hereinafter also referred to as Mn) and a weight average molecular weight (hereinafter also referred to as Mw) in terms of polyethylene glycol and polyethylene oxide. Was calculated.
GPC device: manufactured by Shodex (GPC-101)
Column: manufactured by Shodex (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) 30 mmol / L, tetrahydrofuran) (THF) is 10 ml / L)
Flow rate: 1.0 ml / min Standard sample for preparation of calibration curve: TSK standard polyethylene oxide (weight average molecular weight (Mw) of about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polymer laboratory Polyethylene glycol manufactured by the company (peak top molecular weight (Mp) of about 12,000, 4,000, 1,000). In order to avoid the overlapping of peaks, the measurement was performed by mixing four types of 900,000, 100,000, 12,000, and 1,000, and three types of 150,000, 30,000, and 4,000. Two samples of mixed samples are measured separately.

[Production of liquid crystal cell]
A liquid crystal cell having a configuration of an FFS liquid crystal display element was manufactured.

First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. On the substrate, an IZO electrode having a solid pattern constituting a counter electrode as a first layer is formed. On the counter electrode of the first layer, a SiN (silicon nitride) film formed by the CVD method is formed as the second layer. The second layer SiN film has a thickness of 500 nm and functions as an interlayer insulating film. On the second SiN film, a comb-like pixel electrode formed by patterning an IZO film as the third layer is arranged to form two pixels, a first pixel and a second pixel. ing. The size of each pixel is 10 mm long and about 5 mm wide. At this time, the first-layer counter electrode and the third-layer pixel electrode are electrically insulated by the action of the second-layer SiN film.

The pixel electrode of the third layer has a comb-like shape configured by arranging a plurality of electrode elements having a dogleg shape whose central portion is bent. The width in the short direction of each electrode element is 3 μm, and the distance between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is formed by arranging a plurality of bent-shaped electrode elements in the central portion, the shape of each pixel is not rectangular, but in the central portion like the electrode elements. It has a shape that bends and resembles a bold-faced koji. Each pixel is divided into upper and lower portions with a central bent portion as a boundary, and has a first region on the upper side of the bent portion and a second region on the lower side.

When the first region and the second region of each pixel are compared, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, the electrode element of the pixel electrode is formed to form an angle of + 10 ° (clockwise) in the first region of the pixel, and the pixel in the second region of the pixel. The electrode elements of the electrode are formed so as to form an angle of −10 ° (clockwise). That is, in the first region and the second region of each pixel, the directions of the rotation operation (in-plane switching) of the liquid crystal induced by the voltage application between the pixel electrode and the counter electrode are mutually in the substrate plane. It is comprised so that it may become a reverse direction.

Next, the obtained liquid crystal aligning agent was filtered through a 1.0 μm filter, and then applied to the prepared substrate with electrodes by spin coating. After drying on a hot plate at 100 ° C. for 100 seconds, baking was performed in a hot air circulation oven at 230 ° C. for 20 minutes to obtain a polyimide film having a thickness of 60 nm. This polyimide film is rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 500 rpm, moving speed: 30 mm / sec, indentation length: 0.3 mm, rubbing direction: inclined by 10 ° with respect to the third layer IZO comb-teeth electrode And then washed by irradiating with ultrasonic waves for 1 minute in a 3/7 mixed solvent of isopropyl alcohol and pure water, removing water droplets by air blow, and then drying at 80 ° C. for 15 minutes. A substrate with an alignment film was obtained. In addition, a polyimide film was formed in the same manner as above on a glass substrate having a columnar spacer with a height of 4 μm on which the ITO electrode was formed on the back surface as the counter substrate, and the alignment treatment was performed in the same procedure as above. A substrate with a liquid crystal alignment film was obtained. One set of these two substrates with a liquid crystal alignment film is printed, and the sealant is printed on the substrate leaving the liquid crystal injection port, and the other substrate has the liquid crystal alignment film surface facing and the rubbing direction antiparallel. Then, the sealing agent was cured to produce an empty cell having a cell gap of 4 μm. The liquid crystal MLC-2041 (manufactured by Merck & Co., Inc.) (hereinafter referred to as normal liquid crystal) or the present liquid crystal is sealed with a sealing agent STRUCT BONDTM XN-1500T (manufactured by Mitsui Chemicals, Inc.) by vacuum injection into this empty cell. Liquid crystal added at 5 wt% and heated at 50 ° C. for 1 hour (hereinafter referred to as seal-contaminated liquid crystal) was injected, and the inlet was sealed to obtain an FFS liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C. for 30 minutes and left at 23 ° C. overnight before being used for each evaluation.

[Reduction characteristics of accumulated charge]
The liquid crystal cell (usually liquid crystal is used) is placed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, and the pixel electrode and the counter electrode are short-circuited to have the same potential. The angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured on the two polarizing plates was minimized by irradiating the LED backlight from the bottom of the polarizing plate.

Next, while applying a rectangular wave with a frequency of 30 Hz to this liquid crystal cell, the VT characteristics (voltage-transmittance characteristics) at a temperature of 23 ° C. are measured, and an AC voltage with a relative transmittance of 23% is measured. Calculated. Since this AC voltage corresponds to a region where the change in luminance with respect to the voltage is large, it is convenient to evaluate the accumulated charge via the luminance.

Next, a rectangular wave having an AC voltage with a relative transmittance of 23% and a frequency of 30 Hz was applied for 5 minutes, and then a +1.0 V DC voltage was superimposed and driven for 30 minutes. Thereafter, the DC voltage was turned off, and only a rectangular wave having an AC voltage with a relative transmittance of 23% and a frequency of 30 Hz was applied for 30 minutes.

The faster the accumulated charge is relaxed, the faster the charge accumulation in the liquid crystal cell when the DC voltage is superimposed. Therefore, the accumulated charge relaxation characteristic is a state where the relative transmittance immediately after the DC voltage is superimposed is 30% or more. It was evaluated based on the time required to decrease to 23%. The shorter this time is, the better the stored charge relaxation property is.

[Liquid crystal orientation]
To the liquid crystal cell (usually using liquid crystal), an AC voltage having a relative transmittance of 100% at a frequency of 30 Hz was applied for 150 hours in a constant temperature environment of 60 ° C.
Thereafter, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left as it was at room temperature for one day.

After leaving, the liquid crystal cell is placed between two polarizing plates arranged so that the polarization axes are orthogonal, and the backlight is turned on with no voltage applied so that the brightness of the transmitted light is minimized. The arrangement angle of the liquid crystal cell was adjusted. Then, the rotation angle when the liquid crystal cell was rotated from the angle at which the second area of the first pixel became darkest to the angle at which the first area became darkest was calculated as an angle ΔAngle. Similarly, for the second pixel, the second region and the first region were compared, and a similar angle ΔAngle was calculated. The average value of the angle ΔAngle values of the first pixel and the second pixel was calculated as the angle ΔAngle of the liquid crystal cell. The case where ΔAngle was less than 0.1 ° was evaluated as ◯, and the case where it was 0.1 ° or more was evaluated as ×.

[Vcom stability under seal contamination conditions]
The liquid crystal cell (usually using liquid crystal and seal-contaminated liquid crystal) is placed between two polarizing plates arranged so that their polarization axes are orthogonal, and the pixel electrode and the counter electrode are short-circuited to have the same potential. The angle of the liquid crystal cell was adjusted so that the luminance of the LED backlight transmitted light measured on the two polarizing plates was minimized by irradiating the LED backlight from below the two polarizing plates.

Next, a VT curve (voltage-transmittance curve) was measured while applying an AC voltage with a frequency of 30 Hz to the liquid crystal cell, and an AC voltage with a relative transmittance of 23% or 100% was calculated as the drive voltage. . The liquid crystal cell was heated to 60 ° C., and a 20 mV rectangular wave was applied at a frequency of 1 kHz for 30 minutes.
Thereafter, alternating current driving with a relative transmittance of 100% was applied for 30 minutes. Meanwhile, the minimum offset voltage value was measured every 3 minutes, and the amount of change from the start of measurement to 30 minutes later was calculated. The difference between the minimum offset voltage value change amount after 30 minutes in the cell using the normal liquid crystal and the minimum offset voltage value after 30 minutes in the cell using the seal-contaminated liquid crystal was defined as ΔVcom. The case where ΔVcom was less than 50 mV was indicated as ◯, and the case where 50 VmV or higher was indicated as ×.

Synthesis example

Synthesis of (DA-1)

Under a nitrogen atmosphere, dimethylformamide (390 g), 4-fluoronitrobenzene (65.0 g, 0.461 mol), 4-aminomethylpiperidine (25.0 g, 0.219 mol), potassium carbonate (90.9 g, 0.658 mol) was added and reacted at 60 ° C. After confirming disappearance of the intermediate by HPLC after heating and stirring for 22 hours, potassium carbonate was removed by filtration, and the potassium carbonate was further washed twice with 250 g of dimethylformamide. The resulting solution was distilled off under reduced pressure until the content became 295 g, and 1.50 kg of water was added to precipitate the compound (11), and then the precipitate was collected by filtration and dried to obtain a crude compound (11). I got a thing. The obtained crude product was recrystallized and purified with tetrahydrofuran to obtain a yellow solid compound (11) (58.8 g, 0.165 mol, yield 75.3%).

The structure of the compound (11) was confirmed by obtaining the following spectral data by ¹ H-NMR analysis.
¹ H-NMR (DMSO):
δ = 8.05-7.98 (m, 4H), 7.41 (t, 1H J = 6.8), 7.02 (d, 2H, J = 9.6), 6.68 (d, 2H, J = 9.2), 4.09 (d, 2H, J = 13.6), 3.10 (t, 2H, J = 6.0), 2.98 (t, 2H, J = 12 .0), 1.91-1.89 (m, 1H), 1.89-1.83 (m, 2H), 1.29-1.19 (m, 2H).

Under a nitrogen atmosphere, tetrahydrofuran (400 g), compound (11) (20.0 g, 0.0561 mol), N, N-dimethyl-4-aminopyridine (77.4 mg, 0.634 mmol) were added to a 4-neck flask at 50 ° C. Heated. A mixed solution of di-tert-butyl dicarbonate (15.3 g, 0.0699 mol) and tetrahydrofuran 15.0 g was added dropwise to the solution, and the mixture was reacted for 24 hours. After the content was distilled off under reduced pressure, recrystallization was performed with toluene, and the precipitated crystals were collected by filtration and dried to obtain a yellow solid compound (12) in a yield of 87.3% (22.3 g, 0 .0489 mol).

The structure of the compound (12) was confirmed by obtaining the following spectral data by ¹ H-NMR analysis.
¹ H-NMR (DMSO): δ = 8.21 (d, 2H, J = 8.8), 8.01 (d, 2H J = 9.2), 7.61 (d, 2H, J = 9) .2), 6.98 (d, 2H, J = 9.6), 4.02 (d, 2H, J = 13.6), 3.69 (d, 2H, J = 7.2), 2 .91 (t, 2H, J = 11.6), 1.86-1.70 (m, 1H), 1.66 (d, 2H, J = 11.2), 1.42 (s, 9H) 1.22-1.10 (m, 2H).

Under a nitrogen atmosphere, tetrahydrofuran (447 g), compound (12) (22.3 g, 0.0489 mol), and palladium carbon powder (1.16 g) were placed in a four-necked flask and then replaced with a hydrogen atmosphere and stirred at room temperature for 23 hours. did. After confirming disappearance of the raw material by HPLC, the solution obtained by filtering palladium carbon was distilled off under reduced pressure to obtain a crude product. Chloroform (206 g) was added to the crude product and heated to 60 ° C., and then the liquid separation operation was repeated twice with 60 ° C. water (100 g). Activated carbon (0.754 g) was added to the obtained organic layer and stirred, and then the activated carbon was removed by filtration. The content was concentrated, recrystallized with toluene, and then dried to obtain a light cream solid target product (DA-1) with a yield of 71.3% (13.8 g, 0.0349 mol). .

The structure of the compound (DA-1) was confirmed by obtaining the following spectral data by 1H-NMR analysis.
¹ H-NMR (DMSO): δ = 6.83 (d, 2H, J = 8.0), 6.65 (d, 2H J = 8.4), 6.50 (d, 2H, J = 8) .4), 6.45 (d, 2H, J = 8.4), 5.05 (br, 2H), 4.54 (br, 2H), 3.41 (d, 2H, J = 6.8) ), 3.29 (d, 2H, J = 12.4), 2.36 (t, 2H, J = 10.8), 1.64 (d, 2H, J = 11.6), 1.42 -1.19 (br, 12H).

(Synthesis Example 1)
In a 100 mL four-necked flask containing a stir bar, 4.18 g (14.0 mmol) of (Y-1) and 2.38 g (6.0 mmol) of (DA-1) were taken, and N-methyl-2- 76.7 g of pyrrolidone was added and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 4.14 g (19.0 mmol) of (X-2) was added, and further 19.2 g of N-methyl-2-pyrrolidone was added, followed by stirring at 60 ° C. for 13 hours under a nitrogen atmosphere. A polyamic acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 131 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 10,600 and Mw = 32,800.

Aliquot 18.1 g of this polyamic acid solution into a 100 mL Erlenmeyer flask containing a stirring bar, add 12.1 g of N-methyl-2-pyrrolidone and 10.0 g of butyl cellosolve, and stir with a magnetic stirrer for 2 hours to obtain a solid content. A polyamic acid solution having a concentration of 4.33% by mass was obtained.

(Synthesis Example 2)
(Y-1) 2.83 g (9.5 mmol) and (DA-1) 3.77 g (9.5 mmol)) were placed in a 100 mL four-necked flask containing a stir bar, and N-methyl-2- 75.6 g of pyrrolidone was added and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 3.90 g (17.9 mmol) of (X-2) was added, and further 18.9 g of N-methyl-2-pyrrolidone was added, followed by stirring at 60 ° C. for 13 hours under a nitrogen atmosphere. A polyamic acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 99 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 8,600 and Mw = 26,900.

Aliquot 18.9 g of this polyamic acid solution into a 100 mL Erlenmeyer flask containing a stirring bar, add 12.6 g of N-methyl-2-pyrrolidone and 10.5 g of butyl cellosolve, and stir with a magnetic stirrer for 2 hours to obtain a solid content. A polyamic acid solution having a concentration of 4.51% by mass was obtained.

(Synthesis Example 3)
In a 100 mL four-necked flask containing a stir bar, 1.70 g (5.7 mmol) of (Y-1) and 5.27 g (13.3 mmol) of (DA-1) were taken, and N-methyl-2- 78.3 g of pyrrolidone was added and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 3.94 g (18.1 mmol) of (X-2) was added, and 19.6 g of N-methyl-2-pyrrolidone was added, followed by stirring at 60 ° C. for 13 hours under a nitrogen atmosphere. A polyamic acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 121 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 11,200 and Mw = 39,200.

Aliquot 18.1 g of this polyamic acid solution into a 100 mL Erlenmeyer flask containing a stir bar, add 12.1 g of N-methyl-2-pyrrolidone and 10.1 g of butyl cellosolve, and stir with a magnetic stirrer for 2 hours to obtain a solid content. A polyamic acid solution having a concentration of 3.95% by mass was obtained.

(Synthesis Example 4)
In a 100 mL four-necked flask containing a stir bar, 3.76 g (12.6 mmol) of (Y-1), 0.31 g (2.1 mmol) of (Y-2), 2. 50 g (6.3 mmol)), 67.1 g of N-methyl-2-pyrrolidone was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 2.47 g (12.6 mmol) of (X-1) and 1.60 g (7.4 mmol) of (X-2) were added, and 28.8 g of N-methyl-2-pyrrolidone was further added. In addition, the mixture was stirred at 50 ° C. for 12 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 145 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 10,300 and Mw = 33,700.

This polyamic acid solution (19.1 g) was dispensed into a 100 mL Erlenmeyer flask containing a stirring bar, N-methyl-2-pyrrolidone (11.5 g) and butyl cellosolve (7.6 g) were added, and the mixture was stirred with a magnetic stirrer for 2 hours to obtain a solid content. A polyamic acid solution having a concentration of 4.12% by mass was obtained.

(Synthesis Example 5)
In a 100 mL four-necked flask containing a stirring bar, 6.27 g (21.0 mmol) of (Y-1) and 2.10 g (14.0 mmol) of (Y-2) were taken, and N-methyl-2-pyrrolidone was added. 67.5 g was added and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 6.52 g (33.3 mmol) of (X-1) was added, and further 16.9 g of N-methyl-2-pyrrolidone was added, and the mixture was stirred at 23 ° C. for 4 hours under a nitrogen atmosphere. An acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 740 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 11,100 and Mw = 33,500.

Aliquot 18.6 g of this polyamic acid solution into a 100 mL Erlenmeyer flask containing a stirring bar, add 19.8 g of N-methyl-2-pyrrolidone and 10.3 g of butyl cellosolve, and stir with a magnetic stirrer for 2 hours to obtain a solid content. A polyamic acid solution having a concentration of 4.08% by mass was obtained.

(Synthesis Example 6)
Take 10.44 g (35.0 mmol) of (Y-1) in a 200 mL four-necked flask containing a stir bar, add 103.4 g of N-methyl-2-pyrrolidone, and dissolve by stirring while feeding nitrogen. It was. While stirring this diamine solution, 7.18 g (32.9 mmol) of (X-2) was added, and further 25.8 g of N-methyl-2-pyrrolidone was added, and the mixture was stirred at 60 ° C. for 8 hours under a nitrogen atmosphere to polyamic. An acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 300 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 10,200 and Mw = 29,500.

Take 18.3 g of this polyamic acid solution into a 100 mL Erlenmeyer flask containing a stir bar, add 19.5 g of N-methyl-2-pyrrolidone and 10.2 g of butyl cellosolve, and stir for 2 hours with a magnetic stirrer. A polyamic acid solution having a concentration of 4.25% by mass was obtained.

(Synthesis Example 7)
Take 2.40 g (12.0 mmol) of (Y-3) in a 50 mL four-necked flask containing a stir bar, add 29.8 g of N-methyl-2-pyrrolidone, and dissolve by stirring while feeding nitrogen. It was. While stirring this diamine solution, 3.41 g (11.6 mmol) of (X-3) was added, and 12.8 g of N-methyl-2-pyrrolidone was further added, followed by stirring at 23 ° C. for 25 hours under a nitrogen atmosphere. A polyamic acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 550 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 11,200 and Mw = 33,900.

This polyamic acid solution (16.2 g) was dispensed into a 100 mL Erlenmeyer flask containing a stirring bar, N-methyl-2-pyrrolidone (13.0 g), LS-4668 (0.02 g), and butyl cellosolve (9.73 g) were added, and a magnetic stirrer was added. Was stirred for 2 hours to obtain a polyamic acid solution having a solid content concentration of 5.00% by mass.

(Synthesis Example 8)
Take 8.52 g (37.0 mmol) of (Y-4) in a 100 mL four-necked flask containing a stir bar, add 112.0 g of N-methyl-2-pyrrolidone, and dissolve by stirring while feeding nitrogen. It was. While stirring this diamine solution, 6.89 g (35.2 mmol) of (X-1) was added, and further 27.7 g of N-methyl-2-pyrrolidone was added, followed by stirring at 23 ° C. for 5 hours under a nitrogen atmosphere. A polyamic acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 436 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 18400 and Mw = 47000.

Aliquot 10.3 g of this polyamic acid solution into a 100 mL Erlenmeyer flask containing a stirring bar, add 18.7 g of N-methyl-2-pyrrolidone and 9.68 g of butyl cellosolve, and stir with a magnetic stirrer for 2 hours to obtain a solid content. A polyamic acid solution having a concentration of 4.00% by mass was obtained.

(Synthesis Example 9)
Take 23.79 g (60.0 mmol) of (DA-1) in a 500 mL four-necked flask containing a stir bar, add 300.0 g of N-methyl-2-pyrrolidone, and dissolve by stirring while feeding nitrogen. It was. While stirring this diamine solution, 11.18 g (58.2 mmol) of (X-1) was added, and further 14.7 g of N-methyl-2-pyrrolidone was added, followed by stirring at 23 ° C. for 5 hours under a nitrogen atmosphere. A polyamic acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 184 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 11,300 and Mw = 49,600.

19.3 g of this polyamic acid solution was taken into a 100 mL Erlenmeyer flask containing a stirring bar, added with 11.6 g of N-methyl-2-pyrrolidone and 7.73 g of butyl cellosolve, and stirred for 2 hours with a magnetic stirrer to obtain a solid content. A polyamic acid solution having a concentration of 4.31% by mass was obtained.

(Synthesis Example 10)
In a 100 mL four-necked flask containing a stir bar, 5.07 g (17.0 mmol) of (Y-1) and 1.19 g (3.0 mmol) of (DA-1) were taken, and N-methyl-2- 74.6 g of pyrrolidone was added and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 4.10 g (18.8 mmol) of (X-2) was added, and further 18.7 g of N-methyl-2-pyrrolidone was added, followed by stirring at 60 ° C. for 13 hours under a nitrogen atmosphere. A polyamic acid solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 113 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 9,400 and Mw = 28,900.

Aliquot 18.4 g of this polyamic acid solution into a 100 mL Erlenmeyer flask containing a stir bar, add 12.2 g of N-methyl-2-pyrrolidone and 10.2 g of butyl cellosolve, and stir for 2 hours with a magnetic stirrer to obtain a solid content. A polyamic acid solution having a concentration of 4.33% by mass was obtained.

<Example 1>
A liquid crystal cell was prepared using a solution obtained by mixing the polyamic acid solution obtained in Synthesis Example 1 and the polyamic acid solution obtained in Synthesis Example 5 at a solid content weight ratio of 40:60.

<Example 2>
A liquid crystal cell was produced using a solution obtained by mixing the polyamic acid solution obtained in Synthesis Example 2 and the polyamic acid solution obtained in Synthesis Example 5 at a solid content weight ratio of 40:60.

<Example 3>
A liquid crystal cell was prepared using a solution obtained by mixing the polyamic acid solution obtained in Synthesis Example 3 and the polyamic acid solution obtained in Synthesis Example 5 at a solid content weight ratio of 40:60.

<Example 4>
A liquid crystal cell was prepared using the polyamic acid solution obtained in Synthesis Example 4.

<Comparative Example 1>
A liquid crystal cell was produced using the polyamic acid solution obtained in Synthesis Example 6.

<Comparative example 2>
A liquid crystal cell was prepared using a solution obtained by mixing the polyamic acid solution obtained in Synthesis Example 6 and the polyamic acid solution obtained in Synthesis Example 5 at a solid content weight ratio of 40:60.

<Comparative Example 3>
A liquid crystal cell was produced using the polyamic acid solution obtained in Synthesis Example 7.

<Comparative example 4>
A liquid crystal cell was produced using the polyamic acid solution obtained in Synthesis Example 8.

<Comparative Example 5>
A liquid crystal cell was produced using the polyamic acid solution obtained in Synthesis Example 9.

<Comparative Example 6>
A liquid crystal cell was prepared using a solution obtained by mixing the polyamic acid solution obtained in Synthesis Example 10 and the polyamic acid solution obtained in Synthesis Example 5 at a solid content weight ratio of 40:60.

Claims (9)

1. Of polyamic acid obtained using a tetracarboxylic dianhydride component containing an aromatic tetracarboxylic dianhydride and a diamine component containing a diamine of the following formula (1), and a polyimide obtained by imidizing it A liquid crystal aligning agent containing at least one polymer.
   

   

   R ₁ represents hydrogen or a monovalent organic group, Q ₁ represents an alkylene having 1 to 5 carbon atoms, and Cy represents a divalent heterocyclic ring composed of azetidine, pyrrolidine, piperidine and hexamethyleneimine. A substituent may be bonded to these ring portions, R ₂ and R ₃ are monovalent organic groups, and q and r are each independently an integer of 0 to 4. However, when the sum of q or r is 2 or more, the plurality of R ₂ and R ₃ independently have the above definition.
2. R ₁ is an alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or a thermally leaving group that is replaced with a hydrogen atom by heat, and R ₂ and R ₃ are each independently a hydrogen atom, a methyl group, or a trifluoromethyl group. The liquid crystal aligning agent of Claim 1 which is a cyano group or a methoxy group.
3. The liquid crystal aligning agent according to claim 1 or 2, wherein R ₁ is a linear alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or a tert-butoxycarbonyl group, and Cy is a pyrrolidine ring or a piperidine ring. .
4. The liquid crystal aligning agent of any one of Claim 1 to 3 containing the diamine compound represented by following General formula (2).
   

   

   In the formula (2), R ₁ is a hydrogen atom, a methyl group, or a tert-butoxycarbonyl group, R ₂ is a hydrogen atom or a methyl group, and Q ₁ is a linear alkylene having 1 to 5 carbon atoms.
5. The liquid crystal aligning agent of any one of Claims 1-4 whose aromatic tetracarboxylic dianhydride is 20 mol% or more of all the tetracarboxylic dianhydride components.
6. The liquid crystal aligning agent according to any one of claims 1 to 5, wherein the aromatic tetracarboxylic dianhydride is pyromellitic dianhydride.
7. The liquid crystal aligning agent of any one of Claims 1-6 whose diamine of the said Formula (1) is 30 mol% or more with respect to aromatic tetracarboxylic dianhydride.
8. A liquid crystal alignment film obtained by using the liquid crystal aligning agent according to any one of claims 1 to 7.
9. A liquid crystal display device comprising the liquid crystal alignment film according to claim 8.