KR20130044141A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Abstract

PURPOSE: A liquid crystal aligning agent and a liquid crystal aligning film are provided to provide a liquid crystal display device having high voltage preservation at high temperature and to prevent loss of voltage preservation. CONSTITUTION: A liquid crystal aligning agent comprises at least one compound selected from a polyamic acid which is obtained by reacting tetracarboxylic dianhydride, and imidized polymers thereof. The tetracarboxylic dianhydride comprises an aliphatic hydrocarbon group or alicyclic hydrocarbon group. The diamine comprises a compound represented by chemical formula 1. In chemical formula 1, each of X^1 and X^3 is a single bond, oxygen or sulfur; each of X^2 and X^4 is a C1-6 alkyl group; and each of m and n is 0 or 1.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal alignment material, a liquid crystal alignment film, and a liquid crystal display device,

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film and a liquid crystal display element.

In liquid crystal display elements such as a twisted nematic liquid crystal display element (TN mode) and a transverse electric field display type liquid crystal display element (IPS mode), a liquid crystal is enclosed between a pair of opposing substrates, and the presence or absence of application of an electric field The display is performed by an optical switching function that generates a change in the liquid crystal alignment and modulates light.

The said liquid crystal can orientate a liquid crystal aligning film on a board | substrate to the process direction by the process of rubbing with a cloth with a long hair | bristle, such as rayon or cotton, and what is called a rubbing process. In horizontal alignment type liquid crystal display elements (horizontal alignment mode), such as the said TN mode and IPS mode, the horizontal alignment technique which orientates the said liquid crystal in parallel to a board | substrate surface and a rubbing process direction is needed.

At present, the attempt to use the liquid crystal aligning agent containing the alicyclic polyimide synthesize | combined using the alicyclic tetracarboxylic dianhydride and a diamine compound for the formation of the liquid crystal aligning film suitably used for the said horizontal alignment technique is performed. Compared with the aromatic polyimide used for the conventional liquid crystal aligning agent, the said alicyclic polyimide has little light deterioration in the point which has little absorption in a visible light region, there is little film deterioration at the time of a rubbing process, and viscosity control in a solution state is carried out. This has the advantage of being easy (see Japanese Patent Laid-Open No. 57-128318, Japanese Patent No. 4052308 and Japanese Patent Laid-Open No. 2010-156934).

On the other hand, in liquid crystal display elements on the premise of in-vehicle or outdoor use such as car navigation panels, smartphone panels, etc., where demand is increasing in recent years, it is required to be able to drive in a wider temperature range than conventional liquid crystal display elements. Therefore, although stability of the display characteristic at high temperature is calculated | required by a liquid crystal display element, the liquid crystal display element provided with the conventional liquid crystal aligning film which used the said alicyclic polyimide etc. has insufficient voltage retention at the time of high temperature use, and There is a problem that the thermal deterioration of the voltage holding ratio is large.

Japanese Laid-Open Patent Publication No. 57-128318 Japanese Patent 4052308 Japanese Laid-Open Patent Publication No. 2010-156934

This invention is made | formed in view of the said subject, The liquid crystal aligning agent which can improve the voltage holding ratio at the time of high temperature use of a liquid crystal display element, and can reduce the thermal deterioration of this voltage holding ratio, having the outstanding liquid crystal aligning ability, It is providing the liquid crystal aligning film formed using a liquid crystal aligning agent, and the liquid crystal display element provided with this liquid crystal aligning film.

The invention made to solve the above problems,

As a liquid crystal aligning agent containing at least 1 sort (s) of compound chosen from the group which consists of polyamic acid obtained by making tetracarboxylic dianhydride and diamine react, and its imidation polymer,

Said tetracarboxylic dianhydride contains tetracarboxylic dianhydride (henceforth "aliphatic or alicyclic tetracarboxylic dianhydride") which has an aliphatic hydrocarbon group or an alicyclic hydrocarbon group,

And the said diamine contains the compound represented by following formula (1), It is a liquid crystal aligning agent characterized by the above-mentioned:

(In formula (1), X <^1> and X <^3> are respectively independently a single bond, an oxygen atom, or a sulfur atom; X <^2> and X <^4> are each independently a C1-C6 alkyl group; m and n Are each independently 0 or 1, provided that both m and n do not become 0).

The said liquid crystal aligning agent contains the compound obtained by making a polyamic acid or its imidation polymer react with aliphatic or alicyclic tetracarboxylic dianhydride, and the diamine of the said specific structure, and the voltage retention at the time of high temperature use of a liquid crystal display element The thermal deterioration of the voltage holding ratio can be reduced. In addition, the said liquid crystal aligning agent is a diamine with respect to the solvent of the polyamic acid or its imidation polymer, by using the thing of the structure which has a substituent in the ortho position of the amide in the benzene ring represented by said Formula (1). Solubility can be improved.

In the formula (1), m may be 1 and n may be 0, or m may be 0 and n may be 1. When the benzene ring of the diamine represented by the formula (1) has only one of the substituents as compared with the case of having both X ² -X ¹ -and X ⁴ -X ^3- , the anchoring force is Better than

The tetracarboxylic dianhydride having the aliphatic hydrocarbon group or the alicyclic hydrocarbon group is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride, 1 , 3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1, 3-dione, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1, 3-dione, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride and 1,2,3,4-butanetetracarboxylic acid It is preferable that it is at least 1 sort (s) of compound chosen from the group which consists of anhydrides.

When the said aliphatic or alicyclic tetracarboxylic dianhydride is the said specific compound, the said liquid crystal aligning agent improves the voltage holding ratio at the time of high temperature use of a liquid crystal display element, and makes thermal deterioration of the voltage holding ratio smaller. can do.

The tetracarboxylic dianhydride having the aliphatic hydrocarbon group or the alicyclic hydrocarbon group is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, (1S, 2S, 4R, 5R) -cyclohexanetetracarboxylic acid It is preferable that it is at least 1 sort (s) of compound chosen from the group which consists of dianhydride, (1R, 2S, 4S, 5R) -cyclohexane tetracarboxylic dianhydride, and 2,3,5- tricarboxycyclopentyl acetic dianhydride. .

If the said aliphatic or alicyclic tetracarboxylic dianhydride is the said specific compound, the said liquid crystal aligning agent will further improve the voltage holding ratio at the time of high temperature use of a liquid crystal display element, and will show the thermal deterioration of the voltage holding ratio more. It can be made small.

The tetracarboxylic dianhydride is at least one aromatic compound selected from the group consisting of pyromellitic anhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride. It is preferable to further include.

When the said tetracarboxylic dianhydride further contains the said specific aromatic compound, the orientation of the said liquid crystal aligning agent can be improved.

It is preferable that the said tetracarboxylic dianhydride further contains a pyromellitic anhydride. As described above, the tetracarboxylic dianhydride further includes pyromellitic anhydride, whereby the orientation of the liquid crystal aligning agent can be further improved.

This invention also includes the liquid crystal aligning film formed with the said liquid crystal aligning agent. Since the said liquid crystal aligning film is formed with the said liquid crystal aligning agent, the voltage holding ratio in high temperature use of the liquid crystal display element provided with it can improve, and the thermal deterioration of the voltage holding ratio can be made smaller.

This invention also includes the liquid crystal display element provided with the said liquid crystal aligning film. Since the liquid crystal display element has excellent voltage retention and small thermal deterioration of the voltage retention ratio, the liquid crystal display element is suitably used as a liquid crystal display element that requires driving in a wide temperature range such as a car navigation panel or a smartphone panel. do.

The liquid crystal aligning agent and liquid crystal aligning film of this invention show a high voltage holding ratio also at the time of high temperature use, and can provide a liquid crystal display element with little thermal degradation of the voltage holding ratio. Therefore, the liquid crystal display element of this invention is used suitably as a liquid crystal display element etc. which need to drive in wide temperature ranges, such as a car navigation panel and a smartphone panel.

(Mode for carrying out the invention)

<Liquid crystal aligning agent>

The liquid crystal aligning agent of this invention is a liquid crystal aligning agent containing at least 1 sort (s) of compound chosen from the group which consists of polyamic acid obtained by making tetracarboxylic dianhydride and diamine react, and its imidation polymer, The said tetracarboxylic acid 2 Anhydride contains the tetracarboxylic dianhydride which has an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and the said diamine contains the compound represented by said formula (1), It is characterized by the above-mentioned. In addition, the said liquid crystal aligning agent may contain other arbitrary components, unless the effect of this invention is impaired. Below, polyamic acid, its imide polymer, and other arbitrary components are explained in full detail.

<Polyamic acid>

The polyamic acid contained in the liquid crystal aligning agent of this invention can be obtained by making tetracarboxylic dianhydride and the diamine represented by said formula (1) react. The said tetracarboxylic dianhydride contains an aliphatic or alicyclic tetracarboxylic dianhydride. Moreover, you may further use other arbitrary components, such as a molecular weight modifier, in addition to tetracarboxylic dianhydride and diamine, unless the effect of this invention is impaired.

[Tetracarboxylic acid dianhydride]

The tetracarboxylic dianhydride for synthesizing the polyamic acid in the present invention has a tetracarboxylic dianhydride (hereinafter also referred to as "aliphatic tetracarboxylic dianhydride") having an aliphatic hydrocarbon group or an alicyclic hydrocarbon group. Tetracarboxylic dianhydride (hereinafter also referred to as "alicyclic tetracarboxylic dianhydride").

Here, the aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by having a structure in which at least one hydrogen atom is removed from an aliphatic chain hydrocarbon in the main chain or side chain, and having four carboxyl groups bonded to the chain structure portion in the molecule. Say However, it does not need to be comprised only in a chain structure, and may have a structure of cyclic hydrocarbon or an aromatic ring structure in a part of it.

In addition, an alicyclic tetracarboxylic dianhydride is an acid 2 obtained by having in the main chain | strand or side chain the structure which removed at least 1 hydrogen atom from the alicyclic hydrocarbon, and the four carboxyl groups couple | bonded with this alicyclic hydrocarbon dehydration in a molecule | numerator. Anhydride and two carboxyl groups having the structure of the alicyclic hydrocarbon and the structure of the linear hydrocarbon in the main chain or side chain, and the two carboxyl groups bonded to the alicyclic hydrocarbon group portion and the two carboxyl groups bonded to the chain hydrocarbon group, dehydrated in the molecule The acid dianhydride obtained by making it say. However, it does not need to consist only of an alicyclic hydrocarbon group and a linear hydrocarbon group, and may have an aromatic ring structure in one part.

As said aliphatic tetracarboxylic dianhydride, a 1,2,3, 4- butane tetracarboxylic dianhydride etc. are mentioned, for example. As the alicyclic tetracarboxylic dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride, 1,3,3a , 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3, 3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione , 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetra Hydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6- Dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8 , 10-tetraone, cyclohexane tetracarboxylic dianhydride, and the like. In addition, the thing of that excepting the above can be used as aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride of Unexamined-Japanese-Patent No. 2010-97188.

As aliphatic or alicyclic tetracarboxylic dianhydride, Among these, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5- tricarboxy cyclopentyl acetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a , 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride and 1,2,3,4-butanetetracarboxylic dianhydride are preferred. 1,2,3,4-cyclobutanetetracarboxylic dianhydride, (1S, 2S, 4R, 5R) -cyclohexanetetracarboxylic dianhydride, (1R, 2S, 4S, 5R) -cyclohexanetetracarbon Acid dianhydride and 2,3,5-tricarboxycyclopentyl acetic dianhydride are more preferable, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride is still more preferable. In addition, the said aliphatic or alicyclic tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

As said tetracarboxylic dianhydride, only aliphatic or alicyclic tetracarboxylic dianhydride may be used, but in addition to aliphatic or alicyclic tetracarboxylic dianhydride, tetracarboxylic dianhydride (aromatic tetracarboxylic acid) which has an aromatic ring further 2 anhydrides) may be used in combination. Here, "aromatic tetracarboxylic dianhydride" is an acid anhydride obtained by dehydration of four carboxyl groups having one or more aromatic rings in the main chain or side chain and bonded to the same or different aromatic rings in a molecule.

As said aromatic tetracarboxylic dianhydride, a pyromellitic dianhydride (PMDA), biphenyl tetracarboxylic dianhydride, a benzophenone tetracarboxylic dianhydride, a naphthalene tetracarboxylic dianhydride, 4,4'- jade, for example Sidiphthalic anhydride, The aromatic tetracarboxylic dianhydride of Unexamined-Japanese-Patent No. 2010-97188, etc. are mentioned. Among these, PMDA, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, and 4,4'- oxydiphthalic anhydride are preferable, and PMDA is more preferable. Since PMDA is excellent in liquid-crystal orientation, it is preferable at the point which can improve the orientation in a liquid crystal aligning film by combining with an aliphatic or alicyclic tetracarboxylic dianhydride. On the other hand, when an aliphatic or alicyclic tetracarboxylic dianhydride is used alone, it is preferable at the point which can improve voltage retention compared with the mixed system with aromatic tetracarboxylic dianhydride.

As for the use ratio of an aliphatic or alicyclic tetracarboxylic dianhydride, 10-100 mol% is preferable with respect to the total amount of tetracarboxylic dianhydride, 30-100 mol% is more preferable, 50-100 Mol% is more preferable, and 60-100 mol% is especially preferable. By setting the use ratio of aliphatic or alicyclic tetracarboxylic dianhydride to the above-mentioned specific range, high voltage holding ratio can be expressed and a rubbing tolerance can be made favorable when it is set as a liquid crystal aligning film.

As said tetracarboxylic dianhydride, when using in combination aliphatic or alicyclic tetracarboxylic dianhydride and aromatic tetracarboxylic dianhydride, as a use ratio of aromatic tetracarboxylic dianhydride, the total amount of tetracarboxylic dianhydride is used. It is 5-50 mol% with respect to, 10-45 mol% is preferable and 20-40 mol% is more preferable. By making the use ratio of an aromatic tetracarboxylic dianhydride into the said specific range, liquid crystal alignability can be improved, making the voltage holding ratio at the time of using a liquid crystal aligning film favorable.

[Diamine]

In this invention, at least one part of the diamine used for synthesize | combining a polyamic acid is a compound represented by said Formula (1).

In said formula (1), X <^1> and X <^3> are respectively independently a single bond, an oxygen atom, or a sulfur atom. X ² and X ⁴ each independently represent an alkyl group having 1 to 6 carbon atoms. m and n are 0 or 1 each independently. However, both m and n do not become zero.

As a C1-C6 alkyl group represented by said X <^2> and X <^4> , a methyl group, an ethyl group, a propyl group, a butyl group, etc. are mentioned, for example. Among these, a methyl group and an ethyl group are preferable and a methyl group is more preferable.

As X <^1> and X <^3> , a single bond or -O- is preferable and a single bond is more preferable.

As said m and n, when either one is 0, ie, the case where the benzene ring which the diamine represented by said Formula (1) has has a substituent only in one side of the ortho position of an amide, it is preferable. By such a structure, the solubility to the solvent of the polyamic acid obtained can be improved.

As a compound represented by said formula (1), the compound etc. which are represented by a following formula are mentioned, for example.

As a compound represented by said Formula (1), the compound represented by said Formula (1-1)-(1-5) among these is preferable, The compound represented by said Formula (1-1) (4-amino-N- (4-amino-2-methylphenyl) benzamide) and the compound (4-amino-N- (4-amino-2-methoxyphenyl) benzamide) represented by the formula (1-2) are more preferable, The compound (4-amino-N- (4-amino-2-methylphenyl) benzamide) represented by said formula (1-1) is more preferable.

As a diamine for synthesize | combining the polyamic acid in this invention, only the compound represented by said formula (1) may be used, and other diamine may be used together with the compound represented by said formula (1).

As other diamine which can be used here, an aliphatic diamine, an alicyclic diamine, diamino organosiloxane, an aromatic diamine, etc. are mentioned, for example.

As said aliphatic diamine, 1, 1- metha xylene diamine, 1, 3- propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, etc. are mentioned, for example.

As said alicyclic diamine, 1, 4- diamino cyclohexane, 4,4'- methylenebis (cyclohexylamine), 1, 3-bis (aminomethyl) cyclohexane, etc. are mentioned, for example.

Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane and the like.

As said aromatic diamine, it is o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'- diamino diphenylmethane, 4,4'- diamino diphenyl sulfide, 1, for example. , 5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,7 -Diaminofluorene, 4,4'-diaminodiphenylether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropyl Liden) bisaniline, 4,4 '-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) ratio Phenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacrizine, 3,6-diaminocarbazole, N-methyl-3 , 6-diaminocar Sol, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-bis (4-aminophenyl) -benzidine, N, N'-bis ( 4-aminophenyl) -N, N'-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid, dodecaneoxy-2,4-diaminobenzene, Tetradecaneoxy-2,4-diaminobenzene, pentadecaneoxy-2,4-diaminobenzene, hexadecaneoxy-2,4-diaminobenzene, octadecaneoxy-2,4-diaminobenzene, dodecane Oxy-2,5-diaminobenzene, tetradecaneoxy-2,5-diaminobenzene, pentadecaneoxy-2,5-diaminobenzene, hexadecaneoxy-2,5-diaminobenzene, octadecaneoxy- 2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyl Oxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-diaminobenzoic acid ranostanyl, 3, 6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4'-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diamino Benzoate, 4- (4'-trifluoromethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclo Hexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane , 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, 2,4-diamino-N, N-diallylaniline, 4-aminobenzyl Amine, 3-aminobenzylamine, 1- (2,4-diaminophenyl) piperazin-4-carboxylic acid, 4- (morpholin-4-yl) benzene-1,3-diamine, 1,3-bis (N- (4-aminophenyl) piperidinyl) propane, (alpha)-amino- (omega)-aminophenyl alkylene, the compound represented by following formula (A-1), etc. are mentioned.

In said formula (A-1), R <^1> and R <^3> is a single bond, -O-, -COO-, or -OCO-, respectively. R <^2> is a single bond, a methylene group, or a C2 or 3 alkylene group. p is 0 or 1. q is an integer of 0-2. r is an integer of 1-20. However, both p and q do not become zero. In addition, not all of the R ¹ ~ R ³ is not when a single bond.

As a bivalent group represented by -R <^1> -R <^2> -R <^3> -in said Formula (A-1), it is a methylene group, a C2 or 3 alkylene group, ^* -O-, ^* -COO-, or ^* - O-CH ₂ CH ₂ -O- (where "*" represents a moiety bonded to a diaminophenyl group) is preferable. As the group C _r H _{2r +} 1-, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group , n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nona Decyl group, n-eicosyl group, etc. are mentioned. Moreover, it is preferable that two amino groups in a diaminophenyl group exist in 2, 4-position or 3, 5-position with respect to another group.

As a compound represented by said formula (A-1), the compound etc. which are represented by following formula (A-1-1)-(A-1-3) are mentioned, for example.

As other diamine, in addition to said compound, the compound of that excepting the above among the diamines of Unexamined-Japanese-Patent No. 2010-97188 is mentioned.

It is preferable that the use ratio of the compound represented by said Formula (1) is 10-100 mol% with respect to the whole amount of diamine. By making the use ratio of the compound represented by said formula (1) into the said specific range, the liquid crystal aligning film formed from the said liquid crystal aligning agent can express the outstanding liquid crystal aligning property. Moreover, the liquid crystal display element provided with the said liquid crystal aligning film can also raise the voltage retention of the liquid crystal at the time of high temperature use.

[Molecular Weight Control Agent]

When synthesize | combining a polyamic acid, you may make it synthesize | combine a terminal modified polymer using the appropriate molecular weight modifier with the said tetracarboxylic dianhydride and diamine. By making polyamic acid the polymer of such terminal modification, the applicability | paintability (printability) of a liquid crystal aligning agent can be improved further, without impairing the effect of this invention.

As said molecular weight modifier, an acid monoanhydride, a monoamine compound, a monoisocyanate compound, etc. are mentioned, for example.

Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride, and the like;

As a monoamine compound, For example, aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, etc .;

As a monoisocyanate compound, phenyl isocyanate, naphthyl isocyanate, etc. are mentioned, respectively.

It is preferable to set it as 20 mass parts or less with respect to a total of 100 mass parts of tetracarboxylic dianhydride and diamine to be used, and, as for the usage ratio of the said molecular weight modifier, it is more preferable to set it as 10 mass parts or less.

<Synthesis method of polyamic acid>

The polyamic acid in this invention can be synthesize | combined by making tetracarboxylic dianhydride and diamine react in a solvent. As for the use ratio of tetracarboxylic dianhydride and diamine used for the synthesis reaction of polyamic acid, the ratio in which the acid anhydride group of tetracarboxylic dianhydride is 0.2-2 equivalent with respect to 1 equivalent of the amino group of diamine is 0.3, The ratio which becomes-1.2 equivalent is more preferable.

As a solvent used for the synthesis | combination of polyamic acid, an organic solvent is preferable. -20 degreeC-150 degreeC is preferable, and, as for reaction temperature at this time, 0 degreeC-100 degreeC is more preferable. Moreover, 0.1 hour-24 hours are preferable, and, as for reaction time, 0.5 hour-12 hours are more preferable.

Examples of the organic solvent include aprotic polar solvents, phenols and derivatives thereof, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like.

Examples of the aprotic polar solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, and tetramethylurea. And hexamethylphosphortriamide may be mentioned.

Examples of the phenols and derivatives thereof include m-cresol, xylenol, halogenated phenol and the like.

As said alcohol, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1, 4- butanediol, triethylene glycol, ethylene glycol monomethyl ether, etc. are mentioned, for example.

As said ketone, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. are mentioned, for example.

As said ester, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, diethyl oxalate, diethyl malonate, etc. are mentioned, for example.

Examples of the ethers include diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, Ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetra Hydrofuran etc. are mentioned.

Examples of the halogenated hydrocarbons include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene and the like.

As said hydrocarbon, hexane, heptane, octane, benzene, toluene, xylene, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, etc. are mentioned, for example.

Among these organic solvents, one or more selected from the group consisting of aprotic polar solvents and phenols and derivatives thereof (first group of organic solvents), or one or more kinds selected from the first group of organic solvents, and alcohols It is preferable to use a mixture with at least one member selected from the group consisting of ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second group of organic solvents), and the first group of organic solvents is more preferable. , Aprotic polar solvents are more preferred, and N-methyl-2-pyrrolidone is particularly preferred. Further, at least one selected from the first group of organic solvents, and at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second group of organic solvents) When using a mixture, it is preferable that it is 50 mass% or less with respect to the sum total of the organic solvent of a 2nd group, and the organic solvent of a 2nd group with respect to the sum total of the organic solvent of a 1st group, and it is more preferable that it is 40 mass% or less. And it is more preferable that it is 30 mass% or less.

It is preferable to make the usage-amount of an organic solvent into the amount which will be 0.1-50 mass% with respect to the total amount of tetracarboxylic dianhydride and diamine, with respect to the total amount of reaction solution.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used for preparation of a liquid crystal aligning agent as it is, and may be used for preparation of a liquid crystal aligning agent after isolating the polyamic acid contained in a reaction solution. Or after refine | purifying an isolated polyamic acid, you may use for preparation of a liquid crystal aligning agent. In addition, isolation and purification of a polyamic acid can be performed according to a well-known method.

<Imidation polymer>

The imidation polymer (polyimide) in this invention can be obtained by dehydrating and ring-closing the synthesized polyamic acid and imidizing it. In this case, the reaction solution obtained by dissolving polyamic acid may be directly supplied to the dehydration ring-closing reaction, or the polyamic acid contained in the reaction solution may be isolated and then subjected to dehydration ring-closing reaction. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction.

The polyimide in the present invention may be a complete imide obtained by dehydrating and ring-closing all of the dark acid structures possessed by the polyamic acid as its precursor, or dehydrating and ring-closing only a part of the dark acid structure, such that the dark acid structure and the imide ring structure coexist. A partial imide may be sufficient. It is preferable that the imidation ratio of the polyimide in this invention is 30% or more, It is more preferable that it is 50 to 99%, It is further more preferable that it is 65 to 99%. The imidization rate is a percentage of the ratio of the number of imide ring structures to the sum of the number of amide structure and the number of imide ring structure of polyimide. Here, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of the polyamic acid is preferably carried out by a method of heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent and adding a dehydrating agent and a dehydration ring closure catalyst to the solution and heating it as necessary. It is preferable by the method.

In the method of adding a dehydrating agent and a dehydrating ring-closure catalyst in the solution of the polyamic acid, for example, acid anhydrides such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride can be used as the dehydrating agent. As a usage-amount of a dehydrating agent, it is preferable to set it as 0.01-20 mol with respect to 1 mol of the dark acid structure of polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. It is preferable that the usage-amount of a dehydration ring-closure catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents used. As an organic solvent used for a dehydration ring-closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid is mentioned. The reaction temperature of the dehydration ring-closure reaction is preferably 0 ° C to 180 ° C, more preferably 10 ° C to 150 ° C. The reaction time is preferably 1.0 hour to 120 hours, more preferably 2.0 hour to 30 hours.

In this way, a reaction solution containing polyimide is obtained. This reaction solution may be provided as it is in the preparation of a liquid crystal aligning agent or may be provided in the preparation of a liquid crystal aligning agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution. Alternatively, after the polyimide is isolated, Or may be provided to the preparation of a liquid crystal aligning agent after purification of the isolated polyimide. These purification operations can be performed according to a well-known method.

<Solution Viscosity of Polymer>

The polyamic acid or imidized polymer (henceforth a specific polymer) in this invention obtained as mentioned above has a solution viscosity of 20 mPa * s-800 mPa * s when this is made into the solution of 10 mass% of concentration. It is preferable to have a solution viscosity of 30 mPa · s to 500 mPa · s. Here, the solution viscosity (mPa * s) of the said specific polymer is 25 using the E-type rotational viscometer with respect to the polymer solution of 10 mass% of density | concentration of the specific polymer prepared using N-methyl- 2-pyrrolidone. Let it be the value measured at ° C.

<Other optional components>

Although the liquid crystal aligning agent of this invention contains a specific polymer, you may contain other arbitrary components as needed. As other arbitrary components, an organic solvent, the polymer other than the said specific polymer, the compound which has at least 1 epoxy group in a molecule | numerator (henceforth "epoxy compound"), a functional silane compound, etc. are mentioned, for example. Can be.

[Organic Solvent]

Usually, the liquid crystal aligning agent of this invention melt | dissolves and contains the specific polymer and other arbitrary components arbitrarily blended as needed, and is comprised.

As an organic solvent used for the liquid crystal aligning agent of this invention, N-methyl- 2-pyrrolidone, (gamma) -butyrolactone, (gamma) -butyrolactam, N, N- dimethylformamide, N, N- Dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene Glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether , Diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, di Isobutyl ketone, isoamyl propionate, isoamyl isobutyrate, di-isopentyl ether, ethylene carbonate, propylene carbonate, and the like. Among these, an aprotic polar solvent is preferable, N-methyl-2-pyrrolidone and γ-butyrolactone are more preferable, and N-methyl-2-pyrrolidone is more preferable. These can be used independently, or can mix and use 2 or more types.

[Other polymers]

The other polymers can be used for improving solution properties and electrical properties. Other polymers are polymers other than a specific polymer, for example, the polyamic acid and aromatic tetracarboxylic dianhydride and diamine obtained by making diamine which does not contain the compound represented by Formula (1), and tetracarboxylic dianhydride react Polyamic acid (hereinafter referred to as &quot; other polyamic acid &quot;), polyimide formed by dehydrating and ringing other polyamic acid (hereinafter referred to as &quot; other polyimide &quot;), polyamic acid ester, polyester, polyamide, polysiloxane, Cellulose derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates and the like.

Among these, other polyamic acid or other polyimide is preferable, and other polyamic acid is more preferable. Moreover, as tetracarboxylic dianhydride and diamine used for synthesize | combining other polyamic acid or other polyimide, the compound used for synthesize | combining the said specific polymer is mentioned.

When adding another polymer to a liquid crystal aligning agent, 50 mass% or less is preferable with respect to the total amount of polymers in a liquid crystal aligning agent, 0.1-40 mass% is more preferable, 0.1-30 mass% More preferred.

[Epoxy Compound]

An epoxy compound can be used for the improvement of the mechanical strength in a liquid crystal aligning film. Thereby, peeling of a film | membrane etc. at the time of a rubbing process can be suppressed (rubbing tolerance can be improved), and also the display defect in a liquid crystal display element can be suppressed. In addition, an epoxy compound can also be used for the purpose of the adhesive improvement of a liquid crystal aligning film and a base material.

As said epoxy compound, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol Diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N , N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N', N'- Tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidyl-benzylamine, N, N- diglycidyl-aminomethylcyclohexane and, N, N-diglycid Preference is given to di-cyclohexylamine.

When adding these epoxy compounds to a liquid crystal aligning agent, 40 mass parts or less are preferable with respect to a total of 100 mass parts of the polymer contained in a liquid crystal aligning agent, and 0.1 mass part-30 mass parts are more preferable.

[Functional silane compound]

Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2 -Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy Silane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N- Trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3 , 6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazononanoate, Methyl 3,6-diazananoic acid, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltrie A methoxysilane, 3-glycidoxy propyl trimethoxysilane, 3-glycidoxy propyl triethoxysilane, etc. are mentioned.

When adding these functional silane compounds to a liquid crystal aligning agent, 2 mass parts or less are preferable with respect to a total of 100 mass parts of polymers, and, as for the compounding ratio, 0.02-0.2 mass part is more preferable.

&Lt; Preparation of liquid crystal aligning agent &

The liquid crystal aligning agent of this invention dissolves and adjusts the specific polymer and the other component mix | blended arbitrarily as needed in the said organic solvent.

Solid content concentration (the ratio which the total mass of components other than the solvent of a liquid crystal aligning agent occupies in the total mass of a liquid crystal aligning agent) in the said liquid crystal aligning agent is selected suitably in consideration of viscosity, volatility, etc., Preferably it is 1 mass It is the range of% -10 mass%. That is, the liquid crystal aligning agent of this invention is apply | coated to the surface of a board | substrate as mentioned later, Preferably the coating film which becomes a coating film which is a liquid crystal aligning film, or a liquid crystal aligning film is formed by heating, At this time, when solid content concentration is less than 1 mass%, The film thickness of a coating film becomes small and it is difficult to obtain a favorable liquid crystal aligning film. On the other hand, when solid content concentration exceeds 10 mass%, the film thickness of a coating film becomes excessive and it is difficult to obtain a favorable liquid crystal aligning film, and there exists a possibility that the viscosity of a liquid crystal aligning agent may increase and application characteristics may fall.

A particularly preferable range of the solid concentration is different depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, in the case of a spinner method, the range of 1.5 mass%-4.5 mass% of solid content concentration is especially preferable. When using the printing method, it is preferable to make solid content concentration into the range of 3 mass%-9 mass%, and to make solution viscosity into the range of 12 (mPa * s)-50 (mPa * s) by it. When using the inkjet method, it is preferable to make solid content concentration into the range of 1 mass%-5 mass%, and to make solution viscosity into the range of 3 (mPa * s)-15 (mPa * s). The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10 degreeC-50 degreeC, More preferably, it is 20 degreeC-30 degreeC.

<Liquid Crystal Alignment Film and Liquid Crystal Display Device>

The liquid crystal aligning film of this invention is formed of said liquid crystal aligning agent. Moreover, the liquid crystal display element of this invention is equipped with the said liquid crystal aligning film. Although the said liquid crystal aligning film may be applied to the liquid crystal display element of the horizontal alignment type like IPS type, TN type, and STN type, and may be applied to the liquid crystal display element of the vertical alignment type like VA type, What is applied to a horizontal alignment type It is preferable and it is more preferable to apply to IPS type.

While the manufacturing method of the liquid crystal display element of this invention is demonstrated below, the manufacturing method of the liquid crystal aligning film of this invention is demonstrated also in the description. The liquid crystal display element of this invention can be manufactured by the process of the following (1)-(3), for example. In the step (1), the substrate used is different for each desired operation mode. Steps (2) and (3) are common to each operation mode.

[Step (1): Formation of Coating Film]

First, the said liquid crystal aligning agent is apply | coated on a board | substrate, and then a coating film is formed on a board | substrate by heating a coating surface.

(1-1) when manufacturing a TN type, STN type, or VA type liquid crystal display element;

Two board | substrates with which the patterned transparent conductive film is formed are made into a pair, and the liquid crystal aligning agent of this invention on the each transparent conductive film formation surface, Preferably the offset printing method, the spin coating method, the roll coater method, or the inkjet Each coating surface is apply | coated by the printing method, and then a coating film is formed by heating each coating surface (preferably two-step heating which consists of preheating (prebaking) and baking (postbaking)). Here, as a board | substrate, For example, glass, such as float glass and a soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (alicyclic olefin) can be used. As the transparent conductive film formed on one surface of the substrate, an NESA film (registered trademark of PPG Co., Ltd.) made of tin oxide (SnO ₂ ), an ITO film made of indium tin oxide (In ₂ O ₃ -SnO ₂ ), or the like can be used. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a method of using a mask having a desired pattern when forming a transparent conductive film, or the like You can. At the time of application | coating of the said liquid crystal aligning agent, in order to make adhesiveness of a board | substrate surface and a transparent conductive film and a coating film more favorable, the surface which should form a coating film in a board | substrate surface, a functional silane compound, a functional titanium compound, etc. The pretreatment may be performed beforehand.

The coating surface after apply | coating the said liquid crystal aligning agent is then preheated (prebaked), and also baked (postbaking), and a coating film is formed. Prebaking conditions are 0.1 to 5 minutes, for example at 40-120 degreeC, Post-baking conditions are preferably 120-300 degreeC, More preferably, it is 150-250 degreeC, Preferably it is 5-200 minutes, More Preferably it is 10-100 minutes. The film thickness of the coating film formed becomes like this. Preferably it is 0.001-1 micrometer, More preferably, it is 0.005-0.5 micrometer.

(1-2) the case of manufacturing an IPS type liquid crystal display element;

The liquid crystal aligning agent of this invention is respectively apply | coated to the electrically conductive film formation surface of the board | substrate with which the transparent conductive film patterned by the comb-tooth shape is formed, and the opposing board | substrate with which the conductive film is not formed, and then each coating surface is heated, and a coating film is formed. Form. The material used for the substrate and the transparent conductive film at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film, the pretreatment of the substrate, and the preferred film thickness of the formed coating film are the same as in the above (1-1).

In addition, in any of said (1-1) and (1-2), after apply | coating the said liquid crystal aligning agent on a board | substrate, the coating film used as an oriented film is formed by removing an organic solvent. At this time, when the polymer contained in the liquid crystal aligning agent of this invention is a polyamic acid or the imidized polymer which has an imide ring structure and a dark acid structure, it heats further after coating film formation, and advances dehydration ring-closure reaction, and is already It is good also as a drawing coating film.

[Step (2): rubbing treatment]

When manufacturing a TN type, STN type, or IPS type liquid crystal display element, the coating film formed as mentioned above is subjected to the rubbing process which rubs in a fixed direction with the roll which wound the cloth which consists of fibers, such as nylon, rayon, and cotton, for example. . Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film.

In addition, the above-mentioned rubbing process after the process of changing the pretilt angle of the one part area | region of a liquid crystal aligning film by irradiating an ultraviolet-ray to a part of liquid crystal aligning film with respect to said liquid crystal aligning film, or forming a resist film on a part of the surface of a liquid crystal aligning film; After performing a rubbing process in a different direction, it is possible to improve the field-of-view characteristic of the liquid crystal display element obtained by performing a process which removes a resist film, and making a liquid crystal aligning film have different liquid crystal aligning ability for every area | region.

Moreover, when manufacturing a VA type liquid crystal display element, although the coating film formed as mentioned above can be used as a liquid crystal aligning film as it is, you may perform the said rubbing process.

[Step (3): Construction of Liquid Crystal Cell]

The pair of substrates in which the liquid crystal alignment films are formed as described above is disposed so as to face each other via a gap (cell gap) so that the rubbing direction of the liquid crystal alignment films of the two substrates is perpendicular or antiparallel, and the peripheral portions of the two substrates are Is bonded using a sealing agent, the liquid crystal is injected and filled into the cell gap partitioned by the substrate surface and the sealing agent, and the injection hole is sealed to construct a liquid crystal cell. And the said liquid crystal display element can be obtained by bonding a polarizing plate to the outer surface of a liquid crystal cell so that the polarization direction may coincide or orthogonally cross with the rubbing direction of the liquid crystal aligning film formed in each board | substrate.

As the sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used.

Examples of the liquid crystals include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable, and for example, cif base liquid crystals, subfamily clock liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals and ester liquid crystals. , Terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal, kuban-based liquid crystal, and the like. Furthermore, for these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate; Chiral agents such as those sold under the trade names "C-15" and "CB-15" (Merck); You may add and use strong dielectric liquid crystals, such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate.

As a polarizing plate bonded to the outer surface of a liquid crystal cell, For example, the polarizing plate which sandwiched the polarizing film called "H film | membrane" which absorbed iodine while extending | stretching polyvinyl alcohol, the polarizing plate which consists of a cellulose acetate protective film, or the H film itself Can be mentioned.

The liquid crystal display element of this invention can be effectively applied to various apparatuses, For example, a clock, a portable game, a word processor, a notebook personal computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile telephone And display devices such as various monitors and liquid crystal TVs. In particular, the liquid crystal display device exhibits a high voltage holding ratio even at high temperatures, and since the thermal deterioration of the voltage holding ratio is small, it is necessary to drive in a wide temperature range such as a car navigation panel or a smartphone panel. It is used suitably for an element.

[Example]

Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not restrict | limited to these Examples. In the following synthesis examples, 4-amino-N- (4-amino-2-methylphenyl) benzamide and 4-amino-N- (4-amino-2-methoxyphenyl) benzamide are each made in Japan. The commercial products "MDABAN" and "MODABAN" were used as they were. In addition, the solution viscosity of the polymer in each synthesis example is the value measured at 25 degreeC using the E-type rotational viscometer.

<Synthesis of polyamic acid>

Synthesis Examples 1 to 6

Diamine and tetracarboxylic dianhydride of the quantity shown to following Table 1 were added to N-methyl- 2-pyrrolidone in this order, and it was set as the solution of 15 mass% of monomer concentrations. Then, reaction was performed at room temperature for 6 hours, and the solution containing each polyamic acid ((PA-1), (PA-2), (PAR-1)-(PAR-4)) was obtained, respectively. Each solution was fractionated and N-methyl-2-pyrrolidone (NMP) was added and it was set as the solution of 10 mass% of polyamic acid concentration. The result of having measured the solution viscosity is shown together in following Table 1.

In Table 1, the abbreviation of diamine and tetracarboxylic anhydride has the following meanings, respectively.

<Diamine>

d-1: 4-amino-N- (4-amino-2-methylphenyl) benzamide

d-2: 4-amino-N- (4-amino-2-methoxyphenyl) benzamide

d-3: 4,4-diaminodiphenylamine

d-4: diaminodiphenyl ether

d-5: diaminodiphenylmethylene

d-6: 4-aminophenyl-4'-aminobenzoate

<Tetracarboxylic acid 2 anhydride>

t-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CB)

&Lt; Preparation of liquid crystal aligning agent &

[Examples 1 and 2 and Comparative Examples 1 and 4]

(Gamma) -butyrolactone (BL), N in the solution containing each polyamic acid ((PA-1), (PA-2), (PAR-1)-(PAR-4)) obtained by the said synthesis example, respectively -Methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) are added, and as an epoxy compound, N, N, N ', N'- tetraglycidyl-4,4'-diamino 2 mass parts of diphenylmethanes were added with respect to 100 mass parts of total polymers, and solvent composition made it the solution of BL: NMP: BC = 30: 50: 20 (mass ratio) and 6 mass% of solid content concentration. Each liquid crystal aligning agent was prepared by filtering this solution using the filter of 1 micrometer of pore diameters.

<Production of Liquid Crystal Cell (Liquid Crystal Display Element)>

After coating each liquid crystal aligning agent with a spinner on the glass substrate of thickness 1mm which has the chrome electrode formed in the comb-tooth shape on one side, and prebaking for 1 minute on an 80 degreeC hotplate, it is a 230 degreeC hotplate It post-baked for 10 minutes on the phase, and formed the coating film of about 800 mm in film thickness. About the formed coating film surface, the rubbing process is performed using the rubbing machine which has the roll which wound the cloth made of nylon, at the rotation speed of 1000 rpm of a roll, the movement speed of 25 mm / sec of a stage, and 0.4 mm of a mother-foot indentation length, and liquid-crystal orientation capability. Granted. Furthermore, this board | substrate was ultrasonically cleaned for 1 minute in ultrapure water, and it dried for 10 minutes in a 100 degreeC clean oven, and the board | substrate which has a liquid crystal aligning film on the surface which has a comb-shaped chromium electrode was manufactured. The board | substrate which has this liquid crystal aligning film is called "substrate A."

Separately, on one surface of a glass substrate having a thickness of 1 mm without electrodes, a coating film of each liquid crystal aligning agent is formed in the same manner as described above, subjected to rubbing, washing and drying, and having a liquid crystal aligning film on one surface. Prepared. The board | substrate which has this liquid crystal aligning film is called "substrate B."

Next, after apply | coating the aluminum oxide sphere containing epoxy resin adhesive of diameter 5.5micrometer to the outer edge of the surface which has the rubbing process liquid crystal aligning film of two board | substrates, so that the rubbing direction in each liquid crystal aligning film may become antiparallel, B was placed facing each other via a gap, and the outer edge portions were pressed to abut each other to cure the adhesive. Subsequently, after filling a nematic liquid crystal (MLC-2042 by Merck Co., Ltd.) from a liquid crystal injection port between a pair of board | substrates, the IPS type liquid crystal cell was manufactured by sealing a liquid crystal injection port with an acryl-type photocuring adhesive.

<Evaluation>

The following evaluation was performed about each manufactured liquid crystal cell.

[Voltage maintenance rate (%)]

About the liquid crystal cell produced above, the voltage of 1V was applied for 30 second at 100 degreeC, and the voltage holding ratio (%) after application | release cancellation was measured at 100 degreeC by frame period 167 msec. "Good (A)" when the voltage retention rate exceeds 90%, exceeding 80%, the case of 90% or less is "slightly good (B)", and the case of 80% or less is called "bad (C)". Evaluated. The evaluation results are shown in Table 2.

Thermal Reliability (%)

About the liquid crystal cell produced above, after measuring voltage preservation rate at 100 degreeC by frame period 167 msec, after applying heat stress at 100 degreeC for 30 hours, voltage preservation rate was measured at 100 degreeC again at frame period 167 msec. The value obtained by subtracting the voltage preservation rate (%) after stress application from the voltage preservation rate (%) before stress application is taken as the thermal deterioration equivalent of the voltage preservation rate, and when the value is less than 3%, the thermal reliability is "good (A)", In the case of 3% or more and less than 8%, "slightly good (B)" and 8% or more were evaluated as "failure (C)." The evaluation results are shown in Table 2.

It turned out that the liquid crystal cell provided with the liquid crystal aligning film manufactured using the liquid crystal aligning agent of Example 1 and 2 was high in voltage retention compared with the comparative examples 1-4. Moreover, the liquid crystal cells of Examples 1 and 2 had little thermal deterioration of the voltage holding ratio, and were excellent also in thermal reliability.

The liquid crystal aligning agent and liquid crystal aligning film of this invention show a high voltage holding ratio also at the time of high temperature use, and can provide a liquid crystal display element with little thermal degradation of the voltage holding ratio. Therefore, the liquid crystal display element of this invention is used suitably as a liquid crystal display element etc. which need to drive in wide temperature ranges, such as a car navigation panel and a smartphone panel.

Claims (8)

As a liquid crystal aligning agent containing at least 1 sort (s) of compound chosen from the group which consists of polyamic acid obtained by making tetracarboxylic dianhydride and diamine react, and its imidation polymer,
The tetracarboxylic dianhydride includes a tetracarboxylic dianhydride having an aliphatic hydrocarbon group or an alicyclic hydrocarbon group,
And the said diamine contains the compound represented by following formula (1), The liquid crystal aligning agent characterized by the above-mentioned:

(In formula (1), X <^1> and X <^3> are respectively independently a single bond, an oxygen atom, or a sulfur atom; X <^2> and X <^4> are each independently a C1-C6 alkyl group; m and n Are each independently 0 or 1, provided that both m and n do not become 0). The method of claim 1,
In said formula (1), m is 1 and n is 0, or m is 0 and n is 1, The liquid crystal aligning agent. The method of claim 1,
Tetracarboxylic dianhydride which has the said aliphatic hydrocarbon group or alicyclic hydrocarbon group is 1, 2, 3, 4- cyclobutane tetracarboxylic dianhydride, 2, 3, 5- tricarboxy cyclopentyl acetic dianhydride, 1 , 3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1, 3-dione, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1, 3-dione, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride and 1,2,3,4-butanetetracarboxylic acid The liquid crystal aligning agent which is at least 1 sort (s) of compound chosen from the group which consists of 2 anhydrides. The method of claim 3,
Tetracarboxylic dianhydride which has the said aliphatic hydrocarbon group or alicyclic hydrocarbon group is a 1,2,3,4-cyclobutane tetracarboxylic dianhydride, (1S, 2S, 4R, 5R) -cyclohexanetetracarboxylic acid Liquid crystal aligning agent which is at least 1 sort (s) of compound chosen from the group which consists of dianhydride, (1R, 2S, 4S, 5R) -cyclohexane tetracarboxylic dianhydride, and 2,3,5- tricarboxy cyclopentyl acetic dianhydride. . 5. The method according to any one of claims 1 to 4,
The tetracarboxylic dianhydride is at least one aromatic compound selected from the group consisting of pyromellitic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride. It further contains a liquid crystal aligning agent. The method of claim 5,
Liquid crystal aligning agent in which the said tetracarboxylic dianhydride contains a pyromellitic anhydride further. The liquid crystal aligning film formed with the liquid crystal aligning agent in any one of Claims 1-4. The liquid crystal display element provided with the liquid crystal aligning film of Claim 7.