JP6233309B2 - Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element containing a polymer obtained using a diamine compound having a specific structure.

  The liquid crystal alignment film is a constituent member used for the purpose of controlling the alignment state of the liquid crystal in the liquid crystal display element.

  The liquid crystal alignment film in the liquid crystal display element is formed by, for example, a liquid crystal alignment treatment agent (simply, a liquid crystal alignment agent) comprising a polyimide precursor such as polyamic acid or a polymer such as soluble polyimide as a main component and dissolving them in a solvent. Also used.) Then, it is applied to a TFT (thin film transistor) substrate, a glass substrate with ITO (tin-doped indium oxide) or the like, and baked to form a polymer film. At present, a so-called polyimide-based liquid crystal alignment film is mainly used as the liquid crystal alignment film.

  In recent years, along with higher definition of liquid crystal display elements, various performances are demanded in addition to liquid crystal alignment control in the liquid crystal alignment film used because of the demands of suppressing the decrease in contrast of the liquid crystal display elements and reducing the afterimage phenomenon. It is like that. For example, characteristics such as a high voltage holding ratio, a small residual charge when a DC voltage is applied, and a quick relaxation of the residual charge accumulated by the DC voltage are important.

  In the polyimide-based liquid crystal alignment film, it is possible to improve the above-described problem of residual charges due to application of a DC voltage, and to shorten the time until the afterimage of the liquid crystal display element generated by the DC voltage disappears. In addition to the imide group-containing polyamic acid, a material using a liquid crystal aligning agent containing a tertiary amine having a specific structure (see, for example, Patent Document 1), a specific diamine compound having a pyridine or imidazole skeleton, etc. as a raw material The thing using the liquid crystal aligning agent containing soluble polyimide (for example, refer patent document 2) etc. are known.

  Usually, in these liquid crystal aligning agents, N-methylpyrrolidone is used as a solvent. However, although N-methylpyrrolidone is excellent in solubility and can dissolve the above-mentioned polymer well, on the other hand, when the liquid crystal aligning agent is applied by ink jet, the protrusion is often dissolved. Therefore, a liquid crystal aligning agent that does not use N-methylpyrrolidone as a solvent is demanded.

Japanese Unexamined Patent Publication No. 9-316200 Japanese Unexamined Patent Publication No. 10-104633

However, the polyamic acid and / or polyimide (hereinafter sometimes simply referred to as a polymer) using a specific diamine compound having an aromatic heterocyclic ring such as the above-described pyridine or imidazole skeleton is not limited to N-methylpyrrolidone. Many were poor in solubility in solvents.
Therefore, the polymer used for forming the liquid crystal alignment film is required to realize excellent solubility so as to be soluble in a solvent other than N-methylpyrrolidone.

  An object of the present invention is to provide a liquid crystal aligning agent containing a polymer obtained from a compound used for forming a polymer having excellent solubility, a liquid crystal aligning film formed using the liquid crystal aligning agent, and voltage holding characteristics. Another object of the present invention is to provide a liquid crystal display element having excellent afterimage characteristics derived from residual charges.

As a result of diligent research to achieve the above object, the present inventor has found a specific diamine compound of the present invention having a novel structure, and a liquid crystal alignment containing a polymer obtained by using the diamine compound as a component. It has been found that the agent achieves the above objective.
That is, the present invention has the following gist.

（Ｂｏｃは、ｔ−ブチルオキシカルボニル基を表す。Ｒ^１は単結合、−ＣＨ_２−又は−ＣＨ_２ＣＨ_２−であり、Ｒ^２は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、−Ｎ（ＣＨ_３）ＣＯ−又は−Ｎ（ＣＯＭｅ）−（ここで、Ｍｅはメチル基を表す。）である。Ｒ^３は単結合又は炭素数１〜２０の２価の脂肪族炭化水素基であり、ここで脂肪族炭化水素基の任意の水素原子は、カルボキシ基、エステル基、又はアシルアミノ基に置き換えられていてもよい。Ｒ^４は水素原子又は炭素数１〜２０のアルキル基であり、Ｒ^５は水素原子又は炭素数１〜２０のアルキル基である。）

（Ｂｏｃ、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５は、式（１）のＲ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５の定義と同じである。）1. A polyimide precursor obtained by using a diamine component containing one or more selected from the group consisting of diamine compounds represented by the following formula (1) and formula (2), and obtained by imidizing this polyimide precursor A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of polyimides.

(Boc represents a t-butyloxycarbonyl group. R ¹ is a single bond, —CH ₂ — or —CH ₂ CH ₂ —, and R ² is —O—, —COO—, —OCO—, —NHCO. _{-, - CONH -, - NH} -, - N (CH 3) -, - CON (CH 3) -, - N (CH 3) CO- or -N (COMe) - (wherein, Me represents a methyl group R ³ is a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group is a carboxy group, an ester group, or (It may be replaced by an acylamino group. R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

^{(Boc, R 1, R 2} , R 3, R 4 and ^{R 5} are as defined for ^{R 1, R 2, R 3} , R 4 and ^{R 5} of formula (1).)

（Ｂｏｃは、ｔ−ブチルオキシカルボニル基を表し、Ｍｅはメチル基を表す。）
４．前記重合体の含有量が、液晶配向剤中、１〜２０質量％である、上記１〜３のいずれかに記載の液晶配向剤。2. A polyamic obtained by reacting a diamine component containing one or more selected from the group consisting of diamine compounds represented by the formulas (1) and (2) with a tetracarboxylic dianhydride. 2. The liquid crystal aligning agent according to 1 above, which is an acid.
3. The liquid crystal aligning agent of said 1 or 2 whose said diamine compound is 1 or more types selected from the group which consists of following formula (3) and (4).

(Boc represents a t-butyloxycarbonyl group, and Me represents a methyl group.)
4). The liquid crystal aligning agent in any one of said 1-3 whose content of the said polymer is 1-20 mass% in a liquid crystal aligning agent.

5. A liquid crystal alignment film obtained by applying the liquid crystal aligning agent according to any one of the above 1 to 4, drying, and baking.
6). 6. The liquid crystal alignment film according to 5 above, wherein the firing temperature is 50 to 300 ° C.
7). 7. The liquid crystal alignment film according to 5 or 6 above, wherein the film thickness after firing is 5 to 300 nm.
8). The liquid crystal display element which has a liquid crystal aligning film in any one of said 5-7.

（Ｂｏｃは、ｔ−ブチルオキシカルボニル基を表す。Ｒ^１は単結合、−ＣＨ_２−又は−ＣＨ_２ＣＨ_２−であり、Ｒ^２は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、−Ｎ（ＣＨ_３）ＣＯ−又は−Ｎ（ＣＯＭｅ）−（ここで、Ｍｅはメチル基を表す。）である。Ｒ^３は単結合又は炭素数１〜２０の２価の脂肪族炭化水素基であり、ここで脂肪族炭化水素基の任意の水素原子は、カルボキシ基、エステル基、又はアシルアミノ基に置き換えられていてもよい。Ｒ^４は水素原子又は炭素数１〜２０のアルキル基であり、Ｒ^５は水素原子又は炭素数１〜２０のアルキル基である。）

（Ｂｏｃ、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５は、式（１）のＲ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５の定義と同じである。）
１０．式（１）及び式（２）における、Ｒ^５が水素である、上記９に記載のジアミン化合物。
１１．式（１）及び式（２）における、Ｒ^４がメチル基である、上記９又は１０に記載のジアミン化合物。
１２．下記式（３）及び式（４）のうちのいずれかで表されるジアミン化合物。

（Ｂｏｃは、ｔ−ブチルオキシカルボニル基を表し、Ｍｅはメチル基を表す。）9. The diamine compound represented by either of following formula (1) and formula (2).

(Boc represents a t-butyloxycarbonyl group. R ¹ is a single bond, —CH ₂ — or —CH ₂ CH ₂ —, and R ² is —O—, —COO—, —OCO—, —NHCO. _{-, - CONH -, - NH} -, - N (CH 3) -, - CON (CH 3) -, - N (CH 3) CO- or -N (COMe) - (wherein, Me represents a methyl group R ³ is a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group is a carboxy group, an ester group, or (It may be replaced by an acylamino group. R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

^{(Boc, R 1, R 2} , R 3, R 4 and ^{R 5} are as defined for ^{R 1, R 2, R 3} , R 4 and ^{R 5} of formula (1).)
10. 10. The diamine compound according to 9 above, wherein R ⁵ in formula (1) and formula (2) is hydrogen.
11. The diamine compound according to 9 or 10 above, wherein R ⁴ in formula (1) and formula (2) is a methyl group.
12 The diamine compound represented by either of following formula (3) and formula (4).

(Boc represents a t-butyloxycarbonyl group, and Me represents a methyl group.)

13. The polymer obtained using 1 or more types selected from the group which consists of a diamine compound in any one of said 9-12.

  By using the diamine compound of the present invention, a polymer having excellent solubility is obtained, and a liquid crystal display device having a liquid crystal alignment film formed from a liquid crystal alignment agent containing the polymer has a voltage holding property and a residual property. It has excellent afterimage characteristics derived from electric charges, and is used as a display device that is lightweight, thin and has low power consumption.

It is a X-ray structural-analysis image of the compound (DA-A-2) which is a precursor of a diamine compound.

  Using a diamine compound (also referred to as a specific diamine compound) which is a compound of the present invention, a polyimide precursor formed as a polymer and / or a polyimide obtained by imidizing the polyimide precursor is excellent in solubility, N- It is also soluble in solvents other than methyl pyrrolidone. That is, a liquid crystal aligning agent using a solvent other than N-methylpyrrolidone at least in part can be provided.

Furthermore, the liquid crystal aligning film obtained from the liquid crystal aligning agent containing the polyimide which imidized the polyimide precursor and / or the polyimide precursor which were formed as a polymer using the diamine compound which is the compound of this invention is liquid crystal The movement of charges in the alignment film can be promoted.
Furthermore, the voltage holding ratio is high, and even after being exposed to a high temperature for a long time, the residual charge accumulated by the DC voltage can be quickly relaxed.

  Therefore, a liquid crystal display element having a liquid crystal alignment film obtained from a liquid crystal alignment treatment agent containing a polyimide precursor and / or polyimide as a polymer using the diamine compound of the present invention has excellent reliability, and is large. It can be suitably used for a high-definition liquid crystal television with a screen.

  Hereinafter, the compound of the present invention, that is, a specific diamine compound, a polymer obtained using the specific diamine compound, a liquid crystal aligning agent containing the polymer as a component, a liquid crystal alignment film formed using the same, and a liquid crystal thereof A liquid crystal display element having an alignment film will be described.

<Specific diamine compound>
The specific diamine compound of the present invention is a compound represented by any one of the following formulas (1) and (2).
In the following formulas (1) and (2), Boc represents a t-butyloxycarbonyl group, and the same applies to the following formulas.

（Ｒ^１は単結合、−ＣＨ_２−又は−ＣＨ_２ＣＨ_２−であり、Ｒ^２は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、−Ｎ（ＣＨ_３）ＣＯ−又は−Ｎ（ＣＯＭｅ）−（ここで、Ｍｅはメチル基を表す。）である。
Ｒ^３は単結合又は炭素数１〜２０の２価の脂肪族炭化水素基であり、ここで脂肪族炭化水素基の任意の水素原子は、カルボキシ基、エステル基、又はアシルアミノ基に置き換えられていてもよい。
Ｒ^４は水素原子又は炭素数１〜２０のアルキル基であり、Ｒ^５は水素原子又は炭素数１〜２０のアルキル基である。）

(R ¹ is a single bond, —CH ₂ — or —CH ₂ CH ₂ —, and R ² is —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —N (CH ₃ ) —, —CON (CH ₃ ) —, —N (CH ₃ ) CO— or —N (COMe) — (wherein Me represents a methyl group).
R ³ is a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group is replaced with a carboxy group, an ester group, or an acylamino group. May be.
R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. )

（Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５は、式（１）のＲ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５の定義と同じである。）

^{(R 1, R 2, R 3} , R 4 and ^{R 5} are as defined for ^{R 1, R 2, R 3} , R 4 and ^{R 5} of formula (1).)

  Among the specific diamine compounds represented by the above formulas (1) and (2), diamine compounds represented by the following formulas (3) and (4) are preferable. In the following formulas (3) and (4), Me represents a methyl group, and the same applies to the following formulas.

<Synthesis method and raw material compound of specific diamine compound>
The method for producing the specific diamine compound represented by any one of the above formulas (1) and (2) of the present invention is not particularly limited.
For example, it can be obtained by preparing corresponding dinitro compounds represented by the following formulas (5) and (6), reducing these nitro groups, and converting them to amino groups.

（Ｒ^１は単結合、−ＣＨ_２−又は−ＣＨ_２ＣＨ_２−であり、Ｒ^２は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮ（ＣＨ_３）−、−Ｎ（ＣＨ_３）ＣＯ−又は−Ｎ（ＣＯＭｅ）−（ここで、Ｍｅはメチル基を表す。）である。
Ｒ^３は単結合又は炭素数１〜２０の２価の脂肪族炭化水素基であり、ここで脂肪族炭化水素基の任意の水素原子は、カルボキシ基、エステル基、又はアシルアミノ基に置き換えられていてもよい。
Ｒ^４は水素原子又は炭素数１〜２０のアルキル基であり、Ｒ^５は水素原子又は炭素数１〜２０のアルキル基である。）

(R ¹ is a single bond, —CH ₂ — or —CH ₂ CH ₂ —, and R ² is —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —N (CH ₃ ) —, —CON (CH ₃ ) —, —N (CH ₃ ) CO— or —N (COMe) — (wherein Me represents a methyl group).
R ³ is a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group is replaced with a carboxy group, an ester group, or an acylamino group. May be.
R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. )

  Among these, in the dinitro compounds represented by the above formulas (5) and (6), the following formula (7) and formula (7), which are suitable for the synthesis of the diamine compounds represented by the above formulas (3) and (4), The dinitro compound represented by 8) is preferred.

  The method of reducing the dinitro compound of the formula (5) and the formula (6) represented by the dinitro compound of the formula (7) and the formula (8) is not particularly limited, and usually palladium-carbon, Platinum gas, Raney nickel, iron, tin chloride, platinum black, rhodium-alumina, platinum carbon sulfide, etc. are used as catalysts, and hydrogen gas, hydrazine, hydrogen chloride in solvents such as ethyl acetate, toluene, tetrahydrofuran, dioxane, alcohols, etc. It is possible to apply a reaction using ammonium chloride or the like.

<Polyamic acid>
The polymer of the present invention is at least one polymer selected from the group consisting of a polyimide precursor obtained by using the diamine component containing the specific diamine compound described above, and a polyimide obtained by imidizing this polyimide precursor. In particular, a polyamic acid obtained by the reaction of a diamine component containing the specific diamine compound described above and tetracarboxylic dianhydride and a polyimide obtained by dehydrating and ring-closing this polyamic acid.
These polyimide precursors and polyimide are both contained in the liquid crystal aligning agent, and can be effectively used as a polymer for obtaining a liquid crystal aligning film.

  The liquid crystal alignment film obtained using the polymer of the present invention has a higher voltage holding ratio and is exposed to a high temperature for a long time as the content ratio of the specific diamine compound in the diamine component for forming the liquid crystal alignment film increases. Even so, it is possible to accelerate the relaxation of the residual charges accumulated by the DC voltage.

  For the purpose of enhancing the electrical characteristics described above, it is preferable that 5 mol% or more of the diamine component contained in the liquid crystal aligning agent is a specific diamine compound. More preferably, 10 mol% or more of the diamine component is the specific diamine compound, and more preferably 15 mol% or more.

  Although 100 mol% of the diamine component may be a specific diamine compound, from the viewpoint of uniform coatability when applying a liquid crystal aligning agent, the specific diamine compound is preferably 80 mol% or less of the diamine component, more preferably It is 70 mol% or less.

[Other diamine compounds]
In the present invention, as long as the effects of the present invention are not impaired, in addition to the specific diamine compound, other diamine compounds can be used in combination as a diamine component for forming a polymer. 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'-biphenyl, 3,3'-trifluorome Til-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) silane, dimethyl-bis (4-aminophen ) 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, N-methyl (4,4′-diaminodiphenyl) amine, N-methyl (3,3′-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (2,2'-diaminodiphenyl) amine, N-methyl (2,3'-diaminodiphenyl) amine, 4,4'-diaminobenzophenone, 3,3 '-Diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diamino Nzophenone, 2,3′-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6 diaminonaphthalene 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (4-aminophenyl) ethane, 1,2-bis (3-aminophenyl) ethane, 1,3-bis (4-amino) Phenyl) propane, 1,3-bis (3-aminophenyl) propane, 1,4-bis (4aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3,5-diethyl- 4-aminophenyl) methane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1 , 4-Bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) benzene 4,4 ′-[1,4-phenylenebis (methylene)] dianiline, 4,4 ′-[1,3-phenylenebis (methylene)] dianiline, 3,4 ′-[1,4-phenylenebis ( 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), 1,3-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-amino) Benzamide), N, N ′-(1,4-phenylene) bis (3-aminobenzamide), N, N ′-(1,3-phen Nylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis (3-aminophenyl) terephthalamide, N, N′-bis (4-amino) Phenyl) isophthalamide, N, N′-bis (3-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenylsulfone, 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) hexafluoropropane, 2,2′-bis (3-amino-4-methylphenyl) hexa Fluoropropane, 2,2′-bis (4-aminophenyl) propane, 2,2′-bis (3-aminophenyl) propane, 2,2′-bis (3-amino-4-methylphenyl) propane, 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-amino) Phenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,7- (3-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1, -Bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,10- (4-aminophenoxy) decane, 1, 10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) undecane, 1,11- (3-aminophenoxy) 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-di-aminoundecanoic, 1,12 diamino dodecane and the like.

  Examples of the other diamine compounds include diamine compounds having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, and a cyclic substituent composed of these as a diamine side chain. Specific examples of the diamine compound include diamine compounds represented by the following formulas [DA1] to [DA26].

In the formula ^{[DA1] ~ [DA5],} R 11 is 1 to 22 carbon atoms, an alkyl group or a fluorine-containing alkyl group.

In the above formulas [DA6] to [DA9], R ¹² is —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. , R ¹³ is an alkyl group or fluorine-containing alkyl group having 1 to 22 carbon atoms.

In the above formula [DA10] and formula [DA11], R ¹⁴ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—.
R ¹⁵ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

In the above formulas [DA12] to [DA14], R ¹⁶ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH. ₂ -, or -CH ₂ -.
R ¹⁷ is an alkyl group, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group having 1 to 22 carbon atoms.

In the above formula [DA15] and formula [DA16], R ¹⁸ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, — _{OCH 2 -, - CH 2 -} , - O-, or -NH-.
R ¹⁹ is a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group.

  Furthermore, other diamine compounds include diaminosiloxanes represented by the following formula [DA27].

上記式［ＤＡ２７］中、ｍは、１〜１０の整数である。

In said formula [DA27], m is an integer of 1-10.

  The other diamine compound is a liquid crystal aligning agent containing a polymer, and when the liquid crystal alignment film is formed, one kind or two or more kinds are selected depending on the properties of the liquid crystal orientation, voltage holding, accumulated charge, etc. It can also be used by mixing.

[Tetracarboxylic dianhydride]
The polyamic acid which is a polymer of the present invention can be synthesized by reacting a diamine component containing the above-mentioned specific diamine compound with tetracarboxylic dianhydride.

  In order to obtain the polyamic acid of this invention, the tetracarboxylic dianhydride made to react with a diamine component is not specifically limited. The preferable specific example is given below.

  Pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic Acid dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 1,2,5,6-anthracene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic Acid dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride Bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3 3,3- Oxafluoro-2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4, 5-pyridinetetracarboxylic dianhydride, 2,6-bis (3,4-dicarboxyphenyl) pyridine, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,4,9 , 10-perylenetetracarboxylic dianhydride, 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, oxydiphthaltetracarboxylic dianhydride, 1,2,3,4 -Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cycloheptanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetra Carboxylic dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,4-dicarboxy-1,2,3 4-tetrahydro-1-naphthalene succinic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, bicyclo [4,3,0] nonane-2, 4,7,9- Tracarboxylic dianhydride, bicyclo [4,4,0] decane-2,4,7,9-tetracarboxylic dianhydride, bicyclo [4,4,0] decane-2,4,8,10- Tetracarboxylic dianhydride, tricyclo [6.3.0.0 <2,6>] undecane-3,5,9,11-tetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic Acid dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydraphthalene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2 ] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1,2-dicarboxylic acid Acid dianhydride, tetracyclo [6,2,1,1,0,2,7] Dodeca-4,5,9,10-tetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2: 3,5: 6 dicarboxylic dianhydride, 1,2,4,5-cyclohexanetetra Examples thereof include carboxylic dianhydrides.

  One or two tetracarboxylic dianhydrides are used depending on the properties of the liquid crystal alignment property, voltage holding, accumulated charge, etc. when a liquid crystal alignment film is formed using a liquid crystal alignment agent containing a polymer. These can be used together.

In obtaining the polyamic acid of the present invention by reaction of tetracarboxylic dianhydride and a diamine component, a known synthesis method can be used.
For example, it is a method of reacting a tetracarboxylic dianhydride and a diamine component in an organic solvent. The reaction between the tetracarboxylic dianhydride and the diamine component is advantageous in that it proceeds relatively easily in an organic solvent and no by-product is generated.

  The organic solvent used for the reaction between the tetracarboxylic dianhydride and the diamine component is not particularly limited as long as the generated polyamic acid dissolves. Specific examples are given below.

  N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, isopropyl alcohol, Methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene Glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether , Propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene 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, dioxane, n-hexane, n- Pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, 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, Examples include propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and the like. 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.

  When the tetracarboxylic dianhydride and the diamine component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride is used as it is or in an organic solvent. A method of adding by dispersing or dissolving, a method of adding a diamine component to a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent, and alternately adding a tetracarboxylic dianhydride and a diamine component. Any of these methods may be used. In addition, when the tetracarboxylic dianhydride or diamine component consists of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. May be mixed and reacted to obtain a polymer as a high molecular weight product.

Although the polymerization temperature at the time of making tetracarboxylic dianhydride and a diamine component react can select arbitrary temperature of -20-150 degreeC, Preferably it is the range of -5-100 degreeC.
The reaction can be carried out at any concentration, but if the concentration is too low, it will be difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution will become too high and uniform stirring will occur. Since it becomes difficult, the total concentration of the tetracarboxylic dianhydride and the diamine component in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction is carried out at a high concentration, and then an organic solvent can be added.

  In the polymerization reaction for obtaining a polyamic acid, the ratio of the total number of moles of tetracarboxylic dianhydride and the total number of moles of the diamine component is preferably 0.8 to 1.2. Similar to the normal polymerization reaction, the closer the molar ratio is to 1.0, the higher the molecular weight of the polyamic acid produced.

<Polyamic acid ester>
The polyamic acid ester which is a kind of polyimide precursor in the present invention can be synthesized by the following methods (1) to (3).
(1) When synthesizing from polyamic acid The polyamic acid ester can be synthesized by esterifying the polyamic acid described above.
Specifically, the polyamic acid and the esterifying agent are reacted in the presence of an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C. for 30 minutes to 24 hours, preferably 1 to 4 hours. Can be synthesized.
As the esterifying agent, those that can be easily removed by purification are preferred, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide Dineopentyl butyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -Tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like. The addition amount of the esterifying agent is preferably 2 to 6 molar equivalents per 1 mol of the polyamic acid repeating unit.

  The solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the solubility of the polymer, and these may be used alone or in combination of two or more. Good. The concentration at the time of synthesis is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained.

(2) When synthesize | combining by reaction of tetracarboxylic-acid diester dichloride and diamine Polyamic acid ester is compoundable from the diamine containing the tetracarboxylic-acid diester dichloride and the specific diamine mentioned above.

Specifically, tetracarboxylic acid diester dichloride and diamine are -20 ° C to 150 ° C, preferably 0 ° C to 50 ° C in the presence of a base and an organic solvent, for 30 minutes to 24 hours, preferably 1 to 4 hours. It can be synthesized by reacting.
As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently. The addition amount of the base is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.

The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone in view of the solubility of the monomer and polymer, and these may be used alone or in combination. The polymer concentration at the time of synthesis is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation hardly occurs and a high molecular weight body is easily obtained.
In order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.

(3) When said polyamic acid is synthesize | combined from tetracarboxylic-acid diester and diamine Polyamic acid ester is compoundable by polycondensing the diamine containing the tetracarboxylic-acid diester and the specific diamine mentioned above.
Specifically, tetracarboxylic acid diester and diamine in the presence of a condensing agent, a base, and an organic solvent are 0 ° C to 150 ° C, preferably 0 ° C to 100 ° C, 30 minutes to 24 hours, preferably 3 to 15 hours. It can synthesize | combine by making it react for time.

Examples of the condensing agent include triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N′-carbonyldiimidazole, dimethoxy-1,3,5-triazi Nylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N , N ′, N′-tetramethyluronium hexafluorophosphate, diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate, and the like. It is preferable that the addition amount of a condensing agent is 2-3 times mole with respect to tetracarboxylic-acid diester.
As the base, tertiary amines such as pyridine and triethylamine can be used. The addition amount of the base is preferably 2 to 4 moles relative to the diamine component from the viewpoint that it can be easily removed and a high molecular weight product can be easily obtained.

In the above reaction, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The addition amount of the Lewis acid is preferably 0 to 1.0 times the mole of the diamine component.
Among the methods for synthesizing the three polyamic acid esters, since a high molecular weight polyamic acid ester is obtained, the synthesis method (1) or (2) is particularly preferable.
The polyamic acid ester solution obtained as described above can be polymerized by pouring into a poor solvent while stirring well. Precipitation is performed several times, and after washing with a poor solvent, a purified polyamic acid ester powder can be obtained at room temperature or by heating and drying. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.
The weight average molecular weight of the polyamic acid ester is preferably 5,000 to 300,000, and more preferably 10,000 to 200,000. The number average molecular weight is preferably 2,500 to 150,000, more preferably 5,000 to 100,000.

(Polyimide)
The polymer of this invention can also consist of a polyimide which imidated said polyimide precursor. In the polyimide of the present invention, the dehydration ring closure rate (imidation rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the application and purpose.

  In obtaining the polyimide of the present invention, as a method of imidizing the polyimide precursor, thermal imidation in which a polyimide precursor solution such as polyamic acid is heated as it is, or catalyst imidation in which a catalyst is added to the polyimide precursor solution is used. Can be mentioned.

  The temperature at which the polyimide precursor such as polyamic acid is thermally imidized in the solution is 100 to 400 ° C., preferably 120 to 250 ° C., and the method is performed while removing water generated by the imidization reaction from the system. preferable.

The catalytic imidation of a polyimide precursor such as polyamic acid is performed by adding a basic catalyst and an acid anhydride to a polyamic acid solution and stirring at -20 to 250 ° C, preferably 0 to 180 ° C. Can do.
The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times of the amic acid group, preferably 3 to 3 times. 30 mole times.
Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction.

Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among these, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated.
The imidization rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

  When recovering the produced polyimide from the reaction solution, the reaction solution may be poured into a poor solvent and precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water.

  The polymer precipitated in a poor solvent and collected by filtration can be dried by normal temperature or reduced pressure at room temperature or by heating. Moreover, when the polymer which carried out precipitation collection | recovery is re-dissolved in an organic solvent and the operation which carries out reprecipitation collection | recovery is repeated 2 to 10 times, the impurity in a polymer can be decreased. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

  The molecular weight of the polyimide precursor and polyimide contained in the liquid crystal aligning agent of the present invention is GPC (Gel) in consideration of the strength of the coating film obtained therefrom, the workability during coating film formation, and the uniformity of the coating film. The weight average molecular weight measured by Permeation Chromatography) is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is a coating solution for forming a liquid crystal alignment film, and is a solution in which a polymer component for forming a polymer film is dissolved in a solvent. Here, the polymer component includes at least one polymer of the above-described polymers of the present invention.
The content of the polymer component is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 10% by mass in the liquid crystal aligning agent.

  In the present invention, all of the above-described polymer components may be the above-described polymer of the present invention, and may contain other polymers as long as the effects of the present invention are not impaired. When the polymer component contains another polymer, the content thereof is preferably 0.05 to 4 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 1 part by mass of the polymer of the present invention. Part.

  Other polymers mentioned above include, for example, a polyamic acid obtained by reacting with a tetracarboxylic dianhydride component using a diamine compound other than the specific diamine compound mentioned above, or a polyimide obtained by imidizing the polyamic acid. It is done.

  The solvent used in the liquid crystal aligning agent of the present invention is preferably an organic solvent that dissolves the polymer component, and specific examples thereof are given below.

  Examples of the organic solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfoxide, tetra Methyl urea, 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 Examples include carbonate, diglyme and 4-hydroxy-4-methyl-2-pentanone. These may be used alone or in combination.

  The liquid crystal aligning agent of this invention may contain components other than the polymer component mentioned 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.

  Examples of the solvent that improves the uniformity of the film thickness and the surface smoothness include poor solvents that have low solubility in the polymer component in the liquid crystal aligning agent. Specific examples of the poor solvent 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-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipro Lenglycol 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, methyl 3-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- Low surface such as monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester Examples thereof include a solvent having tension.

  These poor solvents may be used alone or in combination. When using the poor solvent as described above, the poor solvent is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, based on the entire solvent contained in the liquid crystal aligning agent.

  Examples of the compound that improves the uniformity of the film thickness and the surface smoothness when the liquid crystal aligning agent is applied include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant.

  More specifically, for example, EFTOP (registered trademark) EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFac (registered trademark) F171, F173, R-30 (above, Dainippon Ink, Inc.) ), Florard FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard (registered trademark) AG710 (above, manufactured by Asahi Glass Co., Ltd.), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above, AGC Seimi Chemical Co., Ltd.) etc. are mentioned. 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 polymer component contained in the liquid crystal alignment treatment agent. is there.

  Specific examples of the compound for improving 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-tri Toxisilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxy Silane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyl Trimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, poly Lopylene 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′-diaminodiphenylmethane and the like.

  When using a compound that improves adhesion to the substrate, the amount used is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, More preferably, it is 1-20 mass parts. 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 the liquid crystal aligning agent of the present invention, in addition to the components described above, a dielectric material or a dielectric material may be used 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. A conductive substance, and further a crosslinkable compound for the purpose of increasing the hardness and density of the liquid crystal alignment film may be added.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal aligning agent of the present invention can be used as a liquid crystal aligning film after being applied on a substrate, dried, baked to form a coating film, and then subjected to an alignment treatment by rubbing treatment, light irradiation or the like. Further, in vertical alignment applications, etc., it can be used as a liquid crystal alignment film without alignment treatment.
The substrate to be used is not particularly limited as long as it is a highly transparent substrate, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. In addition, it is preferable to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed from the viewpoint of simplifying the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used on one substrate, and in this case, a material that reflects light such as aluminum can be used as the electrode.

A method for applying the liquid crystal aligning agent is not particularly limited, but industrially, a method of performing screen printing, offset printing, flexographic printing, inkjet, or the like is common. Other coating methods include a dipping method, a roll coater method, a slit coater method, and a spinner method, and these may be used depending on the purpose.
In particular, the liquid crystal aligning agent of the present invention is excellent in solubility of the polymer (polymer) component contained, and can be prepared by selecting various solvents. can do.

  Drying after applying the liquid crystal aligning agent on the substrate is carried out by heating means such as a hot plate at 40 to 130 ° C., preferably 50 to 110 ° C., for 20 to 600 seconds, preferably 40 to 300 seconds, and the solvent is evaporated. And a coating film can be formed.

Firing after applying the liquid crystal aligning agent on the substrate and drying it is performed at a temperature of 50 to 300 ° C., preferably 80 to 250 ° C. for 5 to 120 minutes, preferably 8 by a heating means such as a hot plate, oven or IR oven. It can be carried out for ˜60 minutes to imidize the polyimide precursor to form an imidized polymer coating film.
If the thickness of the coating film formed 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. Preferably it is 10-100 nm. When the liquid crystal is aligned horizontally or tilted, the fired coating film is subjected to alignment treatment by rubbing or irradiation with polarized ultraviolet rays.

  The liquid crystal display element of the present invention was prepared by forming a liquid crystal alignment film on the substrate from the liquid crystal aligning agent of the present invention by the above manufacturing method to obtain a substrate with a liquid crystal alignment film, and then preparing a liquid crystal cell by a known method. A liquid crystal display element is obtained.

  As an example of manufacturing a liquid crystal cell, a pair of substrates with a liquid crystal alignment film on which a liquid crystal alignment film is formed is prepared, spacers are scattered on the liquid crystal alignment film of one substrate, and the liquid crystal alignment film surface is on the inside. In this way, the other substrate is bonded and the liquid crystal is injected under reduced pressure to seal, or the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacers are dispersed and then the substrate is bonded and sealed. Can be mentioned. The thickness of the spacer at this time defines the thickness of the liquid crystal between the substrates in the liquid crystal display element, and is preferably 1 to 30 μm, more preferably 2 to 10 μm.

  As described above, a liquid crystal display element manufactured by forming a liquid crystal alignment film using the liquid crystal aligning agent of the present invention has excellent reliability, and is suitable for a large-screen, high-definition liquid crystal television or the like. Available.

  EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention should not be construed as being limited to these examples.

The abbreviations and structures of the compounds used in the synthesis examples, examples and comparative examples of the present invention are shown below.
(Organic solvent)
DMF: N, N-dimethylformamide THF: Tetrahydrofuran NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: ethylene glycol monobutyl ether

(Tetracarboxylic dianhydride)
BDA: 1,2,3,4-butanetetracarboxylic dianhydride PMDA: pyromellitic dianhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride BODA: bicyclo [3,3 0] Octane-2,4,6,8-tetracarboxylic dianhydride

(Diamine compound)
ODA: 4,4′-oxydianiline DDM: 4,4′-diaminodiphenylmethane DA-B: diamine of the following formula DA-B

The ¹ H-NMR, the measurement of molecular weight, and the method of single crystal X-ray structure analysis are shown below [ ¹ H-NMR]
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (manufactured by Varian) 400 MHz
Solvent: deuterated dimethyl sulfoxide (DMSO-d ₆ ) or deuterated chloroform (CDCl ₃ )
Standard substance: Tetramethylsilane (TMS)
Integration count: 8 or 32

[Single-crystal X-ray structure analysis]
Apparatus: APEX2 (manufactured by Bruker)
Measurement temperature: 298.0K
X-ray: Cu

[Molecular weight measurement]
The molecular weight of the polymer was measured as follows using a normal temperature gel permeation chromatography (GPC) device (GPC-101) manufactured by Showa Denko KK and a column (KD-803, KD-805) manufactured by Shodex.

Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L (liter), phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, 10 ml / L of tetrahydrofuran (THF))
Flow rate: 1.0 ml / min Standard sample for preparing calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, and 30000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12000, 4000, and polymer laboratory) 1000).

Synthesis of Aromatic Diamine Compound (1N-Boc-4- (3,5-Diaminobenzoyloxymethyl) -5-methylimidazole) (DA-A) Aromatic diamine compound (DA-A) by the following three-step route ) Was synthesized. The aromatic diamine compound (DA-A) corresponds to the specific diamine compound of the above formula (3).
First Step: Synthesis of 1N-Boc-4-hydroxymethyl-5-methylimidazole (DA-A-1)

4-hydroxymethyl-5-methylimidazole hydrochloride (25.4 g, 171 mmol) was suspended in DMF (102 g) and triethylamine (34.6 g, 342 mmol) was added at 27 ° C. Subsequently, a solution of di-t-butyl dicarbonate (41.1 g, 188 mmol) dissolved in DMF (25 g) was added dropwise over 15 minutes. Thereafter, the reaction mixture was stirred for 18 hours, and disappearance of the raw materials was confirmed by HPLC (thin layer chromatography). Next, the precipitated solid was removed by filtration, and the filtrate was concentrated and dried. Toluene (127 g) was added to the obtained oil, and the precipitated white solid was removed by filtration. Thereafter, the filtrate was concentrated and dried, whereby 1N-Boc-4-hydroxymethyl-5-methylimidazole (DA-A-1) and 3N-Boc-4-hydroxymethyl-5-methylimidazole ( A mixture of DA-C-1) was obtained as a yellow oil (yield 36.19 g, yield 100%). ^{From 1} H-NMR, the two isomer ratios were 60:40.

(DA-A-1) ¹ H-NMR (CDCl ₃ , δ ppm): 8.05 (s, 1H, -N = C (H) -N-), 4.74 (t, J = 5.4 Hz, 1H, OH), 4.56 (d, J = 5.4 Hz, 2H, CH ₂ ), 2.11 (s, 3H, -C = C (N) CH ₃ ), 1.56 (s, 9H, t-Bu).
(DA-C-1) ¹ H-NMR (CDCl ₃ , δ ppm): 8.03 (s, 1H, -N = C (H) -N-), 4.83 (t, J = 5.4 Hz, 1H, OH), 4.29 (d, J = 5.4 Hz, 2H, CH ₂ ), 2.36 (s, 3H, -C = C (N) CH ₃ ), 1.55 (s, 9H, t-Bu).

Second Step: Synthesis of 1N-Boc-4- (3,5-dinitrobenzoyloxymethyl) -5-methylimidazole (DA-A-2)

  1N-Boc-4-hydroxymethyl-5-methylimidazole (DA-A-1) and a mixture of 3N-Boc-4-hydroxymethyl-5-methylimidazole (DA-C-1) (35.8 g, 168.5 mmol) was dissolved in DMF (175 g), triethylamine (40.9 g, 404 mmol) was added, cooled to 3 ° C., and 3,5-dinitrobenzoyl chloride (50.5 g, 219 mmol) was added to DMF (51 g). The dissolved solution was added dropwise over 25 minutes. Thereafter, the reaction mixture was stirred at about 20 ° C. for 3 hours, and HPLC was measured. As a result, 5% of the starting material remained, so that 3,5-dinitrobenzoyl chloride (11.7 g) was further added. , 50.6 mmol) was added and stirred for 16 hours, and it was confirmed by HPLC that the raw materials had disappeared. Next, a mixed solution (680 mL) of ethyl acetate / hexane (2/1 (volume ratio)) was added to the reaction solution, and the organic phase was washed three times with water (220 g). Thereafter, the precipitate was filtered, and the solid was washed twice with ethyl acetate (50 g) and dried, and 1N-Boc-4- (3,5-dinitrobenzoyloxymethyl) -5-methylimidazole (DA-A- 2) (Yield 27.4 g, Yield 40%) was obtained.

^The compound obtained from ¹ H-NMR was a single isomer (DA-A-2 (1N-Boc isomer)). The structure of this isomer was determined by ¹ H-NMR, ¹³ C-NMR and X-ray crystal structure analysis.
FIG. 1 is an X-ray structural analysis image of a compound (DA-A-2) which is a precursor of a diamine compound used in Examples.

The measurement data of ¹ H-NMR and ¹³ C-NMR concerning the obtained compound (DA-A-2 (1N-Boc form)) and a part of the analysis data of X-ray crystal structure analysis are shown below.
(DA-A-2) ¹ H-NMR (CDCl ₃ , δ ppm): 9.21 (d, J = 2.0 Hz, 1H, C ₆ H ₃ (NO ₂ ) ₂ ), 9.16 (d, J = 2.0 Hz, 1H , C ₆ H ₃ (NO ₂ ) ₂ ), 8.07 (s, 1H, -N = C (H) -N-), 5.39 (s, 2H, CH ₂ ), 2.53 (s, 3H, -C = C (N) CH ₃ ), 1.64 (s, 9H, t-Bu).
(DA-A-2) ¹³ C-NMR (CDCl ₃ , δ ppm): 162.5, 148.5, 147.5, 137.4, 133.8, 133.6, 129.6, 128.7, 122.4, 85.9, 70.0, 27.9, 11.0 (each s).

X-ray crystal structure analysis data structural formula of (DA-A-2): C ₁₇ H ₁₈ N ₄ O ₈
Crystalline system: Monoclinic system (Monoclinic)
Space group: P2 ₁ / c
Number of lattices: a = 8.5079 (5) Å
b = 19.6087 (12) Å
c = 11.3540 (8) Å
β = 92.852 (4) °
Z value: 4
R / WR: 0.33 / 0.11

  To the residue obtained by concentrating the organic layer filtrate in the synthesis of 1N-Boc-4- (3,5-dinitrobenzoyloxymethyl) -5-methylimidazole (DA-A-2) in the second step, ethyl acetate / A mixed solution (889 g) of hexane (volume ratio: 2/1) was added, water (363 g) was further added, the mixture was stirred for 1 hour, and the obtained solid was filtered. The filtrate was separated, and a mixed solution of ethyl acetate / hexane (2/1) (889 g) and water (363 g) were added to the organic layer and stirred again, and the resulting solid was filtered. The filtrate was concentrated, a mixed solution (889 g) of ethyl acetate / hexane (1/2) was added to the residue, and the mixture was cooled to 0 ° C. and stirred to obtain a precipitate. The solid was washed twice with ethyl acetate (50 g), dried and 3N-Boc-4- (3,5-dinitrobenzoyloxymethyl) -5-methylimidazole (DA-C-2) (yield 4.3 g) Yield 2%).

^The compound obtained from ¹ H-NMR was a single isomer (DA-C-2 (3N-Boc isomer)). The structure of this isomer was determined by ¹ H-NMR and ¹³ C-NMR.
The measurement data of ¹ H-NMR and ¹³ C-NMR concerning the obtained compound (DA-C-2 (3N-Boc body)) are shown below.
(DA-C-2) ¹ H-NMR (CDCl ₃ , δ ppm): 9.22 (t, J = 2.4 Hz, 1H, C ₆ H ₃ (NO ₂ ) ₂ ), 9.13 (d, J = 2.4 Hz, 2H , C ₆ H ₃ (NO ₂ ) ₂ ), 8.11 (s, 1H, -N = C (H) -N-), 5.64 (s, 2H, CH ₂ ), 2.34 (s, 3H, -C = C (N) CH ₃ ), 1.64 (s, 9H, t-Bu).
(DA-C-2) ¹³ C-NMR (CDCl ₃ , δ ppm) 162.2, 148.6, 147.0, 142.5, 138.7, 133.8, 129.5, 122.4, 120.2, 86.1, 57.5, 27.9, 12.7 (each s).

Third step: Synthesis of aromatic diamine compound (DA-A)

  1N-Boc-4- (3,5-dinitrobenzoyloxymethyl) -5-methylimidazole (DA-A-2) (21.9 g, 53.8 mmol) was suspended in methanol (175 g). After substituting with nitrogen, 5% by mass palladium-carbon (2.18 g, 55% by mass water-containing product) was added, the system was replaced with hydrogen, and the reaction was allowed to proceed at room temperature for 8 days. Thereafter, disappearance of the raw material was confirmed by HPLC (high performance liquid chromatography), and palladium-carbon was removed by filtration. Next, methanol (100 g) as a solvent was distilled off under reduced pressure at 40 ° C. and 120 mmHg, and then 2-propanol (103 g) was added. Again, methanol and 2-propanol (150 g) as solvents were distilled off under reduced pressure at 40 ° C. and 120 mmHg, and then 2-propanol (50 g) was added. Then, the diamine (DA-A) was precipitated by allowing to stand for 1 hour under ice cooling, filtered and dried to obtain an aromatic diamine compound (DA-A) (12.9 g, yield). 69%).

¹ H-NMR (CDCl ₃ , δppm): 7.98 (s, 1H, -N = C (H) -N-), 6.68 (d, J = 2.0 Hz, 1H, C ₆ H ₃ (NH ₂ ) ₂ ) , 6.06 (t, 2H, C ₆ H ₃ (NH ₂ ) ₂ ), 5.14 (s, 2H, CH ₂ ), 2.42 (s, 3H, -C = C (N) CH ₃ ), 1.55 (s, 9H , t-Bu).
¹³ C-NMR (CDCl ₃ , δ ppm): 166.7, 147.5, 147.4, 136.9, 134.8, 131.6, 127.7, 106.7, 105.5, 85.4, 58.9, 27.7, 10.8 (each s).

  3N-Boc-4- (3,5-dinitrobenzoyloxymethyl) -5-methylimidazole (DA-C-2) (2.00 g, 4.92 mmol) was suspended in methanol (16 g). After substituting with nitrogen, 5% by mass palladium-carbon (0.201 g, 57% by mass water-containing product) was added, the system was replaced with hydrogen, and the reaction was allowed to proceed at room temperature for 3 days. After confirming disappearance of the raw material by HPLC, palladium-carbon was removed by filtration, and the solvent was concentrated to dryness to obtain an aromatic diamine compound (DA-C) (1.43 g, yield 84%).

¹ H-NMR (CDCl ₃ , δppm): 8.11 (s, 1H, -N = C (H) -N-), 6.73 (d, J = 2.0 Hz, 1H, C ₆ H ₃ (NH ₂ ) ₂ ) , 6.16 (t, J = 2.0 Hz, 2H, C ₆ H ₃ (NH ₂ ) ₂ ), 5.40 (s, 2H, CH ₂ ), 2.28 (s, 3H, -C = C (N) CH ₃ ), 1.57 (s, 9H, t-Bu).
¹³ C-NMR (CDCl ₃ , δ ppm): 166.6, 147.5, 147.3, 141.6, 138.5, 131.8, 121.1, 106.8, 105.7, 85.8, 56.0, 27.8, 12.7 (each s).

(Preparation of liquid crystal aligning agent)
Example 1
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen introducing tube, 0.457 g (3.00 mmol) of 3,5-diaminobenzoic acid was taken, 3.75 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. . Next, 1.039 g (3.00 mmol) of DA-A, 0.801 g (4.00 mmol) of ODA, and 1.87 g of GBL were added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution, 0.594 g (3.00 mmol) of BDA and 3.00 g of GBL were added and stirred for 2 hours under water cooling. Next, 1.505 g (6.9 mmol) of PMDA and 10.12 g of GBL were added and stirred for 24 hours under water cooling. The viscosity of the obtained polyamic acid solution at a temperature of 25.0 ° C. was 3010 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 17015 and Mw = 42151. Furthermore, to this solution was added 4-glycidoxypropylmethyldiethoxysilane solution diluted to 0.3% by mass with a mixed solution having an NMP / GBL ratio of 2/8 (volume ratio, the same applies hereinafter). .40 g was added to obtain a polyamic acid solution.

  To a 50 mL sample bottle containing a stirrer, 5.63 g of the obtained polyamic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS were added to obtain a liquid crystal aligning agent (A-1). It was. The liquid crystal aligning agent did not show any turbidity or precipitation, and was confirmed to be a uniform solution.

(Example 2)
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 2.355 g (6.80 mmol) of DA-A and 2.02 g (10.20 mmol) of DDM, 6.94 g of NMP, and GBL were taken. 3.47 g was added and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 1.634 g (8.33 mmol) of CBDA and 5.55 g of GBL were added and stirred for 2 hours under water cooling. Next, 2.127 g (8.50 mmol) of BODA and 18.7 g of GBL were added and stirred for 24 hours under water cooling. The viscosity of the obtained polyamic acid solution at a temperature of 25.0 ° C. was 99.3 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 5245 and Mw = 9647. Further, 8.14 g of 3-glycidoxypropylmethyldiethoxysilane solution diluted to 0.3% by mass with a mixed solution having an NMP / GBL ratio of 2/8 was added to this solution to obtain a polyamic acid solution.

  In a 50 mL sample bottle containing a stirrer, 5.63 g of the obtained polyamic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS were added to obtain a liquid crystal aligning agent (A-2). It was. The liquid crystal aligning agent did not show any turbidity or precipitation, and was confirmed to be a uniform solution.

(Comparative Example 1)
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, 0.913 g (6.00 mmol) of 3,5-diaminobenzoic acid was added, 6.67 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. Next, 2.803 g (14.0 mmol) of ODA and 3.34 g of GBL were added and stirred and dissolved while feeding nitrogen. While stirring this diamine solution, 1.189 g (6.00 mmol) of BDA and 4.67 g of GBL were added and stirred for 2 hours under water cooling. Next, 2.923 g (13.4 mmol) of PMDA and 18.7 g of GBL were added and stirred for 24 hours under water cooling. The viscosity of the obtained polyamic acid solution at a temperature of 25.0 ° C. was 3701 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 11194 and Mw = 26713. Further, 7.83 g of 3-glycidoxypropylmethyldiethoxysilane solution diluted to 0.3% by mass with a mixed solution having an NMP / GBL ratio of 2/8 was added to this solution to obtain a polyamic acid solution.

  In a 50 mL sample bottle containing a stirrer, 5.63 g of the obtained polyamic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS were added to obtain a liquid crystal aligning agent (B-1). It was. The liquid crystal aligning agent did not show any turbidity or precipitation, and was confirmed to be a uniform solution.

(Comparative Example 2)
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, 0.457 g (3.00 mmol) of 3,5-diaminobenzoic acid was added, 3.53 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. Next, 0.778 g (3.00 mmol) of DA-B, 0.801 g (4.00 mmol) of ODA, and 1.76 g of GBL were added and stirred and dissolved while feeding nitrogen. While stirring this diamine solution, 0.594 g (3.00 mmol) of BDA and 2.82 g of GBL were added and stirred for 2 hours under water cooling. Next, 1.505 g (6.9 mmol) of PMDA and 9.52 g of GBL were added and stirred for 24 hours under water cooling. However, polymer precipitation occurred during the reaction, and a liquid crystal aligning agent could not be prepared.

(Comparative Example 3)
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, 3.965 g (20.0 mmol) of DDM was taken, 7.15 g of NMP and 3.58 g of GBL were added, and the mixture was stirred and dissolved while feeding nitrogen. . While stirring this diamine solution, 1.922 g (9.80 mmol) of CBDA and 5.72 g of GBL were added, and the mixture was stirred for 2 hours under water cooling. Next, 2.502 g (10.0 mmol) of BODA and 12.2 g of GBL were added and stirred for 24 hours under water cooling. The viscosity of the obtained polyamic acid solution at a temperature of 25.0 ° C. was 1534 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 13910 and Mw = 41256. Further, 8.39 g of a 3-glycidoxypropylmethyldiethoxysilane solution diluted to 0.3% by mass with a mixed solution having an NMP / GBL ratio of 2/8 was added to this solution to obtain a polyamic acid solution.

  In a 50 mL sample bottle containing a stirrer, 5.63 g of the obtained polyamic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS are added to obtain a liquid crystal aligning agent (B-2). It was. The liquid crystal aligning agent did not show any turbidity or precipitation, and was confirmed to be a uniform solution.

<Comparative Example 4>
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 1.76 g (6.80 mmol) of DA-B and 2.02 g (10.20 mmol) of DDM, 6.43 g of NMP, and GBL were taken. 3.22 g was added and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 1.634 g (8.33 mmol) of CBDA and 5.15 g of GBL were added and stirred for 2 hours under water cooling. Next, 2.127 g (8.50 mmol) of BODA and 17.3 g of GBL were added and stirred for 24 hours under water cooling. However, polymer precipitation occurred during the reaction, so that a polyamic acid solution was not obtained, and a liquid crystal aligning agent could not be prepared.

(Measurement of volume resistivity)
(Example 3)
Using the liquid crystal aligning agents obtained in Examples and Comparative Examples, the solution was filtered through a 0.2 μm filter and then spin-coated on a glass substrate with an ITO transparent electrode. Then, it dried for 2 minutes on an 80 degreeC hotplate, and baked at 230 degreeC for 20 minutes, and formed the coating film with a film thickness of 100 nm. Aluminum was vapor-deposited on the surface of the coating film through a mask to form a 1.0 mmφ upper electrode (aluminum electrode), which was used as a sample for volume resistivity measurement. A DC voltage of 1 V was applied between the ITO electrode and the aluminum electrode of this sample, the current value 180 seconds after the voltage application was measured, and the volume resistivity was calculated from this value, the electrode area, and the film thickness.
The measurement results are summarized in Table 1.

[Production of IPS mode liquid crystal cell]
Example 4
After the liquid crystal aligning agents obtained in the examples and comparative examples are filtered through a 0.2 μm filter, the electrodes have comb-like shapes and are arranged so that the comb-tooth portions are spaced apart from each other. A glass on which an electrode for driving an in-plane switching (hereinafter referred to as IPS) having a pair of ITO electrodes (electrode width: 10 μm, electrode interval: 10 μm, electrode height: 50 nm) is formed. The substrate was spin coated. Then, it dried for 2 minutes on an 80 degreeC hotplate, and baked at 230 degreeC for 20 minutes, and obtained the coating film with a film thickness of 100 nm. This polyimide film was rubbed with a rayon cloth (roll diameter: 120 mm, rotation speed: 1000 rpm, moving speed: 20 mm / sec, pushing amount: 0.3 mm, angle of 15 degrees with respect to the IPS comb electrode). Then, ultrasonic cleaning was performed in pure water for 1 minute, and drying was performed at 80 ° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. Further, a coating film was similarly formed on a glass substrate having a columnar spacer with a height of 4 μm on which no electrode was formed as a counter substrate, and the same orientation treatment was performed.

  The above-mentioned two substrates are combined into one set, and a sealing agent is printed on one substrate and bonded so that the rubbing directions of the two substrates are opposite to each other by 180 degrees, and then the sealing agent is cured to be emptied. A cell was produced. Liquid crystal MLC-2041 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an IPS mode liquid crystal cell.

[Measurement of voltage holding ratio]
(Example 5)
Each liquid crystal cell (IPS mode liquid crystal cell) produced in Example 4 was used, and measurement was performed using a 6254 type liquid crystal physical property evaluation apparatus manufactured by Toyo Corporation. A voltage of 4V is applied to each liquid crystal cell for 60 μs at a temperature of 60 ° C., and the voltage holding ratio after 1667 msec from application release ((voltage after 1667 msec from application release) / voltage immediately after application) × 100%) Was measured.
The measurement results are summarized in Table 1.

[Evaluation of residual image derived from residual charge by DC voltage]
(Example 6)
Each liquid crystal cell (IPS mode liquid crystal cell) produced in Example 4 was placed on a light source, and after measuring VT characteristics (voltage-transmittance characteristics), an AC voltage / 60 Hz rectangular shape with a transmittance of 23% Waves were applied for 10 minutes. Next, 1V DC was superimposed on 23.0% AC voltage / 60 Hz rectangular wave and driven for 30 minutes. Thereafter, the DC voltage was turned off, and again driven with only 23% AC voltage / 60 Hz rectangular wave for 30 seconds, and the transmittance of the liquid crystal cell thereafter was measured. The difference (ΔT (%)) between the obtained transmittance and the initial transmittance (23.0%) was evaluated as an afterimage derived from a residual charge generated by a DC voltage in the liquid crystal display element.
The evaluation results are summarized in Table 1.

From the results of Table 1, it can be seen that the polymers of the examples of the present invention are excellent in solubility. Furthermore, the liquid crystal aligning film obtained from the liquid crystal aligning agent of an Example has a low volume resistivity compared with the liquid crystal aligning film obtained from the liquid crystal aligning agent of a comparative example. That is, the compounds of the examples were able to form a polymer having excellent solubility, the liquid crystal aligning agent was easy to prepare, and a liquid crystal alignment film having a low volume resistivity could be formed.
Furthermore, it was found that the liquid crystal cell having the liquid crystal alignment film of the example had excellent afterimage characteristics and a high voltage holding ratio, and had performance required for a liquid crystal display element.

By using the liquid crystal aligning agent containing the polymer of the present invention, it becomes possible to obtain a liquid crystal aligning film having excellent electrical characteristics and improved display defects such as afterimages. Therefore, it can be used in large-sized liquid crystal televisions for which high display quality has been demanded, or in liquid crystal display elements such as smartphones and tablet devices for which display quality has been rapidly improved in recent years.
In addition, the entire content of the specification, claims, drawings and abstract of Japanese Patent Application No. 2012-188874 filed on August 29, 2012 is cited herein as the disclosure of the specification of the present invention. Incorporated.

Claims (7)

The polyimide precursor obtained using the diamine component containing 1 or more types selected from the group which consists of the diamine compound represented by following formula (3), and the diamine compound represented by Formula (4) , and this polyimide precursor A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of polyimides obtained by imidizing a body.

(Boc represents a t-butyloxycarbonyl group, and Me represents a methyl group.) A diamine component containing one or more selected from the group consisting of the diamine compound represented by the formula (3) and the diamine compound represented by the formula (4) , a tetracarboxylic dianhydride, and the polyimide precursor The liquid crystal aligning agent according to claim 1, which is a polyamic acid obtained by the reaction. The liquid crystal aligning agent of Claim 1 or 2 whose content of the said polymer is 1-20 mass% in a liquid crystal aligning agent. Ru obtained liquid crystal alignment agents or these according to any one of claims 1 to 3 liquid crystal alignment film. Film thickness, is 5 to 300 nm, a liquid crystal alignment film according to claim 4. The liquid crystal display element which has a liquid crystal aligning film of Claim 4 or 5 . Obtained by imidizing a polyimide precursor obtained by using one or more selected from the group consisting of diamine compounds represented by any of the following formulas (3) and (4) , or this polyimide precursor Polyimide .

( Boc represents a t-butyloxycarbonyl group, and Me represents a methyl group. )

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