KR20150111376A - Liquid-crystal alignment material, liquid-crystal display element employing same, and novel diamine - Google Patents

Abstract

(식 중, R 은 탄소 원자수가 1 ∼ 25 인 포화 탄화수소기를 나타낸다)A novel diamine, a polyamic acid, a polyimide, and a liquid crystal alignment which are useful for obtaining a liquid crystal alignment treatment agent capable of obtaining a liquid crystal alignment film in which the voltage holding ratio is high and a DC voltage is applied to the liquid crystal cell, Thereby providing a treating agent. A liquid crystal alignment treatment agent comprising at least one of a polyamic acid obtained by reacting a diamine component containing a diamine and a tetracarboxylic acid dianhydride component of the following formula [1], or a polyimide obtained by imidizing the polyamic acid.
[Chemical Formula 1]

(Wherein R represents a saturated hydrocarbon group having 1 to 25 carbon atoms)

Description

(LIQUID-CRYSTAL ALIGNMENT MATERIAL, LIQUID-CRYSTAL DISPLAY ELEMENT EMPLOYING SAME, AND NOVEL DIAMINE), a liquid crystal display device using the same,

The present invention relates to a liquid crystal alignment treatment agent and a liquid crystal alignment film used in a liquid crystal display element and further relates to a novel diamine useful as a raw material for polyamic acid or polyimide used in the liquid crystal alignment treatment agent.

At present, as a liquid crystal alignment film of a liquid crystal display element, a so-called polyimide-based liquid crystal alignment film obtained by applying and firing a liquid crystal alignment treatment agent (also referred to as liquid crystal aligning agent) containing a polyimide precursor such as polyamic acid or a soluble polyimide solution as a main component It is mainly used.

The liquid crystal alignment film is used for the purpose of controlling the alignment state of the liquid crystal. However, from the viewpoints of suppressing the lowering of the contrast of the liquid crystal display element and reducing the afterimage phenomenon due to the high definition of the liquid crystal display element, the liquid crystal alignment film used also has a high voltage holding ratio, The accumulation of the stored charge RDC of the capacitor C is small, or the characteristic that the charge stored by the DC voltage is quickly relaxed becomes important.

In a polyimide-based liquid crystal alignment film, a liquid crystal aligning agent containing a tertiary amine having a specific structure is used in addition to polyamic acid or an imide group-containing polyamic acid as a short time until the after-image caused by the DC voltage disappears (See, for example, Patent Document 1), and a liquid crystal aligning agent containing a soluble polyimide in which a specific diamine having a pyridine skeleton or the like is used as a raw material (see, for example, Patent Document 2).

In addition, in the polyimide-based liquid crystal alignment film, the time until the after-image produced by the DC voltage is high is high and the voltage holding ratio is high. In addition, it is possible to add one carboxylic acid group in the molecule to the polyamic acid and the imidized polymer A liquid crystal aligning agent containing a very small amount of a compound selected from a compound containing one carboxylic acid anhydride group in the molecule and a compound containing one tertiary amino group in the molecule (see, for example, Patent Document 3 ) Is known.

However, by simply shortening the time until the afterimage disappears, it can not be said that measures against the afterimage phenomenon are sufficient.

Japanese Patent Application Laid-Open No. 9-316200 Japanese Patent Application Laid-Open No. 10-104633 Japanese Patent Application Laid-Open No. 8-76128

SUMMARY OF THE INVENTION In view of the above situation, it is an object of the present invention to provide a liquid crystal alignment treatment agent capable of obtaining a liquid crystal alignment film having a high voltage holding ratio and a high initial charge accumulation even when a DC voltage is applied to the liquid crystal cell, Diamine, polyamic acid, and polyimide useful in the present invention.

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have completed the present invention. That is, the present invention has the following points.

1. A liquid crystal alignment treatment agent containing at least one of a polyamic acid obtained by reacting a diamine component containing a diamine and a tetracarboxylic acid dianhydride component of the following formula [1], or a polyimide obtained by imidizing the polyamic acid.

(Wherein R represents a saturated hydrocarbon group having 1 to 25 carbon atoms)

2. The liquid crystal alignment treatment agent according to 1 above, wherein the diamine represented by the formula [1] is 20 to 100 mol% of the total diamine component used in the synthesis of the polyamic acid.

3. The liquid crystal alignment treatment agent according to 1 or 2 above, wherein the diamine represented by the formula [1] is a diamine having two amino groups at the position of meta or para.

4. The liquid crystal alignment treatment agent according to 1 above, wherein the diamine component represented by the following formula [2] is contained in the diamine component to be reacted with the tetracarboxylic acid dianhydride component.

(Wherein Ar is a benzene ring or a naphthalene ring, R ₁ is an alkylene group having 1 to 5 carbon atoms, and R ₂ is a hydrogen atom or a methyl group)

5. The liquid crystal alignment treatment agent according to any one of 1 to 4 above, wherein the tetracarboxylic acid dianhydride component comprises a tetracarboxylic acid dianhydride having an alicyclic structure or an aliphatic structure.

6. A liquid crystal alignment film obtained from the liquid crystal alignment treatment agent according to any one of 1 to 5 above.

7. A liquid crystal display element comprising the liquid crystal alignment film according to 6. above.

8. The diamine of the following formula [1-1].

(Wherein R < ₃ > is a linear alkyl group having 1 to 5 carbon atoms)

9. The diamine of the following formula [1-2].

(Wherein R < ₄ > is a saturated hydrocarbon group having 3 to 8 carbon atoms and containing at least one cyclic structure)

10. A polyamic acid obtained by reacting a diamine component containing a diamine as described in 8 or 9 above with a tetracarboxylic acid dianhydride component.

11. A polyimide obtained by imidizing the polyamic acid according to the above 10.

The liquid crystal alignment treatment agent of the present invention can provide a liquid crystal alignment film having a high voltage holding ratio and in which charge accumulation does not occur even when a direct current voltage is applied to the liquid crystal cell and the liquid crystal alignment film is used to produce a liquid crystal panel having excellent characteristics . Further, the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention hardly causes problems such as cutting and scratches, even in the rubbing treatment.

By using the novel diamine, polyamic acid, or polyimide of the present invention, excellent liquid crystal alignment treatment agents as described above can be easily obtained.

In addition, the novel diamine of the present invention is easy to synthesize and can be used as a raw material for polyamic acid, polyimide and the like to increase the solubility of the resulting polyamic acid or polyimide in a solvent. The polyamic acid or polyimide of the present invention has excellent solubility in a solvent, so that a uniform coating film can be obtained.

The liquid crystal alignment treatment agent of the present invention comprises a polyamic acid obtained by reacting a diamine component and a tetracarboxylic acid dianhydride component or a polyimide obtained by imidizing an amic acid thereof and a diamine component represented by the formula [ Wherein the liquid crystal alignment treatment agent is a liquid crystal alignment treatment agent. By using this diamine, the obtained liquid crystal alignment film has a high voltage holding ratio, and furthermore, charge can not be accumulated even when a DC voltage is applied to the liquid crystal cell.

≪ Diamine of formula [1] >

In the diamine represented by the formula [1], the position of each substituent on the benzene ring is not particularly limited. From the viewpoint of the orientation of the liquid crystal when used as a liquid crystal alignment film, the positional relationship between the two amino groups is preferably meta or para, and more preferably from the standpoint of enhancing solvent solubility of the polyamic acid or polyimide. When the positional relationship between the two amino groups is meta, that is, in the case of the 1,3-diaminobenzene structure, the position of the methylene ester is preferably at the 4 or 5 position, and particularly, the nucleophilic (nucleophilic) From the viewpoint of the effect and easy synthesis, the 5 position is more preferable.

In the diamine represented by the formula [1], R is a saturated hydrocarbon group having 1 to 25 carbon atoms. The saturated hydrocarbon group may be a linear or branched alkyl group or may contain a cyclic structure. Specific examples of such saturated hydrocarbon groups include methyl group, ethyl group, linear alkyl group from n-propyl group to n-pentacosyl group; propyl group, a 1-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, an isobutyl group, Branched alkyl group branched at any point in the range of up to 25 carbon atoms in addition to the 1,1-dimethylbutyl group, the 3,3-dimethylbutyl group and the like; A cycloalkyl group represented by a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and the like; Cyclohexylmethyl group, cyclohexylmethyl group, cyclohexylmethyl group, 2-cyclopropylethyl group, 2-cyclobutylethyl group, 2-cyclopentylethyl group, 2-cyclohexylethyl group, 2-methylcyclopropyl group, 1-methyl A cyclohexyl group, a 2-methylcyclohexyl group, a 4-tert-butylcyclohexyl group, and a bicyclohexyl group; a group in which an alkyl group and a cycloalkyl group or a combination of two or more cycloalkyl groups are combined; A group having a condensed ring such as a bicyclo [2,2,1] heptan-2-yl group, an adamantan-1-yl group or an adamantan-1-ylmethyl group.

In the diamine represented by the formula [1], the number of carbon atoms of R is preferably small to some extent from the viewpoint of accumulation of the accumulated charge (RDC) when the liquid crystal alignment film is formed. For example, the number of carbon atoms of R is preferably 1 to 17, more preferably 1 to 8. From the viewpoint of liquid crystal aligning property and rubbing resistance, R is preferably a linear alkyl group having a smaller molecular weight. Accordingly, specific examples of R in the diamine represented by the formula [1] in view of the liquid crystal aligning property, the rubbing resistance, the accumulation property of the accumulated charge (RDC), and the like include methyl, ethyl, Is a relatively small molecular weight alkyl group selected from tyl groups.

On the other hand, when R has a cyclic structure such as a cycloalkyl group, the solubility of polyamic acid or polyimide is higher. Thus, specific examples of R in view of the solubility of a polyamic acid or a polyimide in a diamine represented by the formula [1] and the accumulation property of an accumulated charge (RDC) in a liquid crystal alignment film include cyclopropyl Cyclohexylmethyl group, cyclohexylmethyl group, cyclohexylmethyl group, 2-cyclopropylethyl group, 2-cyclobutylethyl group, 2-cyclopentylethyl group, 2-cyclohexylmethyl group, Hexylethyl group, 2-methylcyclopropyl group, 1-methylcyclohexyl group, 2-methylcyclohexyl group and the like.

The method for synthesizing a diamine represented by the formula [1] is not particularly limited. For example, a dinitro compound represented by the following formula [3] is synthesized, and the nitro group is further reduced by an ordinary method to convert it into an amino group . ≪ / RTI >

(R in the above formula is the same as R in the formula [1]).

The dinitro compound represented by the formula [3] can be synthesized by reacting the dinitrobenzyl alcohol corresponding to the position of the substituent of the desired diamine with the R of the desired diamine in the presence of a base such as pyridine or triethylamine, Can be synthesized by reacting the corresponding carboxylic acid chloride or acid dianhydride.

(R in the above formula is the same as R in the formula [1]).

Examples of the dinitrobenzyl alcohol corresponding to the position of the preferable substituent of the diamine of the above formula [1] include 2,4-dinitrobenzyl alcohol, 3,5-dinitrobenzyl alcohol, 2,5-dinitrobenzyl alcohol, have.

Among the diamines represented by the formula [1], the diamines of the following formula [1-1] or the diamines of the following formula [1-2] are novel diamines particularly useful for the liquid crystal alignment treatment agent of the present invention.

(Wherein R < ₃ > is a linear alkyl group having 1 to 5 carbon atoms)

(Wherein R < ₄ > is a saturated hydrocarbon group having 3 to 8 carbon atoms and containing at least one cyclic structure)

The diamine of the formula [1-1] or [1-2] can be synthesized by the same method as the diamine represented by the other formula [1].

In the diamine of the formula [1-1] or [1-2], the positional relationship between the two amino groups is preferably meta or para, and from the viewpoint of enhancing the solubility of the polyamic acid or the polyimide in the solvent, More preferable.

Specific preferred examples of the diamine represented by the formula [1-1] are shown below, but the present invention is not limited thereto.

The diamines of the above formulas [4] to [18] can be classified into the following form [a], [b] and [c] depending on the position of the substituent on the benzene ring. The diamine of the formula [5], the formula [8], the formula [11], the formula [14] or the formula [17] is particularly preferable.

(R in the above formulas [a] to [c] is the same as R in formula [1]),

Of the diamines represented by the formula [1-2], specific examples of the diamine represented by the formula [b] are shown below, but the present invention is not limited thereto.

≪ Diamine component >

The diamine represented by the above formula [1] can be reacted with a tetracarboxylic acid dianhydride to obtain a polyamic acid, and the polyamic acid can be imidized to form a polyimide.

In the present invention, the diamine component used in the synthesis of the polyamic acid may be only the diamine represented by the formula [1], and one or more selected from the other diamines may be combined.

By containing the diamine represented by the formula [1] as the diamine component, the solvent solubility of the obtained polyamic acid and the polyimide obtained by imidizing the polyamic acid can be enhanced. Furthermore, the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent containing the polyamic acid or polyimide has a high voltage holding ratio and does not accumulate charge even when a DC voltage is applied to the liquid crystal cell. In order to obtain such characteristics, the diamine represented by the formula [1] is preferably 20 to 100 mol%, more preferably 40 to 100 mol%, and particularly preferably 20 to 100 mol% of the total diamine component used in the synthesis of the polyamic acid Is 50 to 100 mol%.

The diamine used in combination with the diamine represented by the formula [1] in the diamine component is not particularly limited. Specific examples of such diamines are shown below.

Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'- Dimethyldicyclohexylamine, isophoronediamine, and the like.

Examples of the aromatic diamine include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, Diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 3,5-diaminobenzoic acid, 1,4-diamino- 2,5-dichlorobenzene, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-2,2'-dimethylbibenzyl, 4,4'- diaminodiphenylmethane , 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 2,2'-diaminostilbene , 4,4'-diaminostilbene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfide, 4,4'- Diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis Phenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,5-bis Bis (4-aminophenoxy) methyl] propane, 2,2-bis [4- (4-aminophenoxy) benzene, Bis [4- (4-aminophenoxy) phenyl] propane, bis [4- Bis (4-aminophenyl) phenyl] sulfone, 1,1-bis (4-aminophenyl) cyclohexane, 4-aminophenyl) fluorene, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2- , 2,4-diaminodiphenylamine, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoanthraquinone, 1,3-diaminopyrrene, 1,6-diamino Pyrene, 1,8-diaminopyrene, 2,7-diaminofluorene, 1,3-bis (4-aminophenyl) tetramethyldisiloxane, benzidine, 2,2'-dimethylbenzidine, (4-aminophenyl) ethane, 1,3-bis (4-amyl Bis (4-aminophenyl) pentane, 1,6-bis (4-aminophenyl) hexane, 1,7-bis (Aminophenyl) heptane, 1,8-bis (4-aminophenyl) octane, 1,9- (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) pentane, Bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9- Di (4-aminophenyl) pentane-1, di (4-aminophenyl) Di (4-aminophenyl) hexane-1,6-dioate, di (4-aminophenyl) heptane- Di (4-aminophenyl) nonane-1,9-dioate, di (4-aminophenyl) decane- Bis [4- (4-aminophenoxy) phenoxy] butane, 1,5-bis [4- (4-aminophenoxy) phenoxy] pentane, 1,6-bis [4- (4-aminophenoxy) phenoxy] Heptane, 1,8-bis [4- (4-aminophenoxy) phenoxy] octane, 1,9- (4-aminophenoxy) phenoxy] decane, and the like.

Examples of the heterocyclic diamine include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, Diaminocarbazole, 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole Sol and the like.

Examples of the aliphatic diamine include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, Diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6- 2,5-dimethylhexane, 1,7-diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino- -Diamino-5-methylheptane, 1,12-diaminododecane, 1,18-diaminooctadecane, 1,2-bis (3-aminopropoxy)

Examples of the aromatic-aliphatic diamine include diamines represented by the following formula [2].

Wherein Ar represents a benzene ring or a naphthalene ring, R ₁ is an alkylene group having 1 to 5 carbon atoms, and R ₂ is a hydrogen atom or a methyl group.

In the diamine represented by the formula [2], it is preferable that Ar is a benzene ring and R ₂ is a hydrogen atom.

Specific examples of the diamine represented by the formula [2] include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, Amino-N-methylphenethylamine, 3- (3-aminopropyl) aniline, 4- (3-aminopropyl) aniline Aniline, 4- (4-aminobutyl) aniline, 3- (4-methylaminopropyl) aniline, 3- (5-aminopentyl) aniline, 3- (5-methylaminopentyl) aniline, 4- (5-aminophenyl) aniline, 4- (6-aminonaphthyl) methylamine, 2- (6-aminonaphthyl) ethylamine, 3- (6-aminonaphthyl) Ethylamine, and the like, but the present invention is not limited thereto.

The use of the diamine represented by the formula [2] in combination with the diamine represented by the formula [1] is preferable because the solubility of the obtained polymer in an organic solvent is further improved and the liquid crystal alignment property is excellent when used as a liquid crystal alignment film . Further, such a combination can increase the effect of increasing the pretilt angle of the liquid crystal by the diamine described below, and therefore, the use amount thereof can be reduced in the case of obtaining the same pretilt angle. Since the printing property of the liquid crystal alignment treatment agent tends to deteriorate when the amount of the diamine that can increase the pretilt angle of the liquid crystal is increased, the printing property of the liquid crystal alignment treatment agent is expected to be improved if the use amount of the diamine can be reduced .

The preferred content of the diamine represented by the formula [2] is 10 to 50 mol%, more preferably 20 to 40 mol%, of the total diamine component. When the diamine represented by the formula [2] is contained, the preferred content of the diamine represented by the formula [1] is 20 to 90 mol%, more preferably 30 to 80 mol%, of the total diamine component.

Examples of the diamine that can be included in the diamine component in the synthesis of the polyamic acid to increase the pretilt angle of the liquid crystal alignment film include long chain alkyl groups, perfluoroalkyl groups, aromatic cyclic groups, aliphatic cyclic groups, Diamines having substituted substituents, steroid skeleton groups, and the like are known. These diamines can also be used in combination with the diamines represented by the formula [1] in the present invention. Specific examples of the diamine having such a substituent are shown below, but the present invention is not limited thereto. In the structures exemplified below, j represents an integer of 5 to 20, and k represents an integer of 1 to 20.

Of the above diamines, the diamines of the formula [19] are preferred because of their excellent liquid crystal alignability. Since the diamines of the formulas [26] to [33] are very high in the ability of exhibiting the pretilt angle, the OCB (Optically Compensated Bend) liquid crystal alignment film (hereinafter referred to as OCB orientation film) and the vertical alignment mode liquid crystal orientation film It is preferably used for an alignment film for VA).

For example, in the TN liquid crystal alignment film (at a pretilt angle of 3 to 5 °), the content of the diamine of the formula [19] is made 10 to 30 mol% of the total diamine component and the orientation film for OCB or the alignment film for VA The tilt angle is 10 to 90 degrees), the content of the diamine of the formulas [26] to [33] may be 5 to 40 mol% of the entire diamine component, but the present invention is not limited thereto.

≪ Tetracarboxylic acid dianhydride component >

In the polyamic acid or polyimide of the present invention, the tetracarboxylic acid dianhydride component to be reacted with the diamine component is not particularly limited and may be one kind of tetracarboxylic acid dianhydride, And a bicarboxylic acid dianhydride may be used in combination.

In the liquid crystal alignment treatment agent of the present invention, the tetracarboxylic acid dianhydride having an alicyclic structure or an aliphatic structure may be used as the tetracarboxylic acid dianhydride to be reacted with the diamine component, It is preferable to use an anhydride. Examples of the tetracarboxylic acid dianhydride having an alicyclic or aliphatic structure include 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane Tetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclo Butane tetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,2,4,5 -Cyclohexanetetracarboxylic acid dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, [4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride], 1,2,3,4- Butanetetracarboxylic acid dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid dianhydride, 3,3 ', 4,4'-dicyclo Silane tetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid Acid anhydride, tricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid-3,4: 7,8-2 anhydride, hexacyclo [6.6.0.12,7.03,6.19, 14.010,13] hexadecane-4,5,11,12-tetracarboxylic acid-4,5: 11,12-2 anhydride. Of these, 1,2,3,4-cyclobutane tetra Use of a carboxylic acid dianhydride is particularly preferable because an alignment film excellent in liquid crystal alignability can be obtained.

Further, when the aromatic tetracarboxylic acid dianhydride is used in combination, the liquid crystal alignability can be improved and the charge accumulated in the liquid crystal cell can be quickly eliminated. Examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracarboxylic acid Biphenyltetracarboxylic acid dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 2,3,3', 4- Benzophenone tetracarboxylic acid dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid 2-anhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, and the like. Among them, pyromellitic dianhydride is particularly preferable.

Considering the balance of the respective properties such as the solubility of the obtained polyamic acid or polyimide, the orientation of liquid crystal, the voltage holding ratio, and the accumulated charge, it is preferable to use tetracarboxylic acid dianhydride having an alicyclic structure or aliphatic structure and aromatic tetracarboxylic acid dianhydride Is preferably 90/10 to 50/50, more preferably 80/20 to 60/40 in terms of the former / the latter molar ratio.

<Polymerization Reaction>

In the present invention, the polymerization reaction method of the tetracarboxylic acid dianhydride component and the diamine component is not particularly limited. Generally, a polymerization reaction can be carried out by mixing in an organic solvent to form a polyamic acid, and the polyamic acid can be converted into a polyimide by dehydration ring closure.

As a method for mixing the tetracarboxylic acid dianhydride component and the diamine component in an organic solvent, a method in which a solution prepared by dispersing or dissolving a diamine component in an organic solvent is stirred and the tetracarboxylic acid dianhydride component is dispersed in the organic solvent A method in which a diamine component is added to a solution in which a tetracarboxylic acid dianhydride component is dispersed or dissolved in an organic solvent, a method in which a tetracarboxylic acid dianhydride component and a diamine component are alternately added, and the like In the case where the tetracarboxylic acid dianhydride component or the diamine component is composed of a plurality of compounds, the polymerization reaction may be carried out in a state in which these plural kinds of components are mixed in advance, or the polymerization reaction may be performed individually and sequentially.

The temperature at which the tetracarboxylic acid dianhydride component and the diamine component are polymerized in an organic solvent is usually 0 to 150 ° C, preferably 5 to 100 ° C, more preferably 10 to 80 ° C. When the temperature is higher, the polymerization reaction is terminated quickly. However, when the temperature is too high, a polymer having a high molecular weight may not be obtained.

If the total concentration of the tetracarboxylic acid dianhydride component and the diamine component is too low, it becomes difficult to obtain a polymer having a high molecular weight. If the concentration is too high, the viscosity of the reaction solution becomes excessively high Preferably from 1 to 50% by mass, and more preferably from 5 to 30% by mass, since it is difficult to uniformly agitate. The polymerization is carried out at a high concentration in the initial stage, and then an organic solvent may be added.

The organic solvent used in the polymerization reaction is not particularly limited as long as it dissolves the produced polyamic acid. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 3-methoxy- , Dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide,? -Butyrolactone, and 1,3-dimethylimidazolidinone. These may be used alone or in combination. Further, even a solvent that does not dissolve the polyamic acid may be used in combination with the solvent insofar as the produced polyamic acid does not precipitate. In addition, since moisture in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the resulting polyamic acid, it is preferable to use an organic solvent that is dehydrated and dried as much as possible.

The ratio of the tetracarboxylic acid dianhydride component to the diamine component used in the polymerization reaction of the polyamic acid is preferably 1: 0.8 to 1: 1.2 in terms of the molar ratio, and the molecular weights of the polyamic acid Lt; / RTI &gt; By controlling the molecular weight of the polyamic acid, the molecular weight of the polyimide obtained after imidation can be adjusted.

The molecular weight of the polyamic acid or polyimide of the present invention is not particularly limited. When it is contained in the liquid crystal alignment treatment agent, it is preferably 2,000 to 200,000 in weight average molecular weight from the viewpoint of the strength of the obtained coating film and ease of handling as a liquid crystal alignment treatment agent And more preferably from 5,000 to 50,000.

<Synthesis of polyimide>

The polyimide of the present invention is a polyimide obtained by imidizing the polyamic acid. Imidization of polyamic acid can be carried out by stirring in an organic solvent in the presence of a basic catalyst and an acid anhydride for 1 to 100 hours.

Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferable since it has a basicity suitable for proceeding the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, acetic anhydride is preferable because the obtained polyimide can be easily purified after completion of imidization. As the organic solvent, a solvent used in the above-mentioned polyamic acid polymerization reaction can be used.

The imidization rate of polyimide can be controlled by controlling the amount of catalyst, reaction temperature, and reaction time. The amount of the basic catalyst at this time is preferably 0.2 to 10 times, more preferably 0.5 to 5 times, the molar amount of the acyl group. The amount of the acid anhydride is preferably 1 to 30 times, more preferably 1 to 10 times, the molar amount of the acidic group. The reaction temperature is preferably -20 to 250 占 폚, more preferably 0 to 180 占 폚.

Although the imidization ratio of the polyimide of the present invention is not particularly limited, when it is contained in the liquid crystal alignment treatment agent, the imidization ratio is preferably 40% or more, more preferably 60% or more, Or more, and particularly preferably 80% or more.

In the solution of the polyimide thus obtained, since the added catalyst remains, when it is used in the liquid crystal alignment treatment agent, it is preferable to recover and wash the polyimide before use.

The recovery of the polyimide can be carried out by introducing the imidized solution into a stirring solvent which has been stirred and then filtering out the precipitated polyimide. Examples of the poor solvent include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene and the like. The recovered polyimide may be washed with this poor solvent. The polyimide thus recovered and washed can be converted into a powder at normal temperature or under reduced pressure at room temperature or by heating and drying.

Such an operation can also be carried out for the polyamic acid. For example, in the case where it is not desired to contain the solvent used in the polymerization of polyamic acid in the liquid crystal alignment treatment agent, or when unreacted monomer components or impurities in the reaction solution are to be removed, the above precipitation recovery and purification may be carried out.

&Lt; Liquid crystal alignment treatment agent &

The liquid crystal alignment treatment agent of the present invention is a coating liquid containing at least one kind of polymer selected from polyamic acid and polyimide obtained as described above.

For example, the reaction solution of the polyamic acid or polyimide may be used as it is, or it may be diluted, and the product obtained by precipitation and recovery from the reaction solution may be redissolved in an organic solvent. In addition, in the diluting or redissolving step, adjustment of the solvent composition for controlling the coating property on the substrate and addition of additives for improving the properties of the coating film can be carried out. Further, a solution of polyimide having a structure different from the above may be mixed with a polyamic acid solution, or another resin component may be added.

The organic solvent used in the dilution or redissolution step is not particularly limited as long as it dissolves the contained polymer. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 3-methoxy- , 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, dimethylsulfone, hexamethylsulfoxide,? -Butyrolactone, Lt; / RTI &gt; Among them, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone and? -Butyrolactone are preferably used. These may be used alone or in combination of two or more.

Examples of the solvent to be added for controlling the coating property of the liquid crystal alignment treatment agent to the substrate include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy- Propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, diethylene glycol diethyl ether, propylene glycol monoacetate, propylene glycol diacetate, dipropylene Propylene glycol monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactic acid methyl ester , Lactic acid ethyl ester, n-propyl lactic acid ester, n-butyl lactic acid ester, and lactic acid diacid ester. Solvents such as polyamic acid or polyimide are dissolved in these solvents Not even, but contains a solvent, in a range that the resin does not precipitate, it can be mixed with the liquid crystal alignment treating agent of the present invention. Particularly, it is known that by properly mixing a solvent having a low surface tension, coating film uniformity can be improved upon application to a substrate, and is also preferably used in the liquid crystal alignment treatment agent of the present invention. Of these, butyl cellosolve, ethyl carbitol, dipropylene glycol monomethyl ether, or diethylene glycol diethyl ether are particularly preferable from the viewpoint of solubility of polyimide.

Examples of the additives for improving the properties of the coating film include 3-aminopropylmethyldiethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane And the like. The addition of these silane coupling agents can improve the adhesion of the coating film to the substrate. However, if it is added excessively, it may cause aggregation of resin components such as polyamic acid and polyimide. Therefore, polyamic acid and polyimide The silane coupling agent is preferably added in an amount of 0.5 to 10% by mass, more preferably 1 to 5% by mass, based on the resin component.

The solid concentration of the liquid crystal alignment treatment agent of the present invention can be suitably changed according to the setting of the thickness of the liquid crystal alignment film to be formed, but it is preferably 1 to 10% by mass. If it is less than 1% by mass, it becomes difficult to form a uniform and defect-free coating film. If it is more than 10% by mass, the storage stability of the solution may be deteriorated. The concentration of the polyamic acid or polyimide of the present invention in this solid content is not particularly limited, but is preferably 1% by mass or more, more preferably 3% by mass or more from the viewpoint of the obtained liquid crystal alignment film characteristic, Particularly preferably not less than 5% by mass.

The liquid crystal alignment treatment agent thus obtained is preferably filtered before it is applied to the substrate.

<Liquid crystal display element>

The liquid crystal alignment treatment agent of the present invention can be used as a coating film by applying it on a substrate, followed by drying and firing, and by rubbing the coated film surface, it is used as a liquid crystal alignment film for rubbing. It is also used as a VA liquid crystal alignment film and a photo alignment film which are not rubbed.

In this case, the substrate to be used is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as a glass substrate, an acrylic substrate, or a polycarbonate substrate can be used, and a substrate on which an ITO electrode for liquid crystal driving is formed is used Is preferable from the viewpoint of process simplification. In the reflection type liquid crystal display device, an opaque material such as a silicon wafer may be used only for a substrate on one side. In this case, a material for reflecting light such as aluminum can also be used as the electrode in this case.

As a method of applying the liquid crystal alignment treatment agent, a spin coating method, a printing method, an ink jet method, or the like can be mentioned. In terms of productivity, the flexographic printing method is widely used industrially and is also preferable in the liquid crystal alignment treatment agent of the present invention Lt; / RTI &gt;

The drying step after applying the liquid crystal alignment treatment agent is not necessarily required, but it is preferable to include a drying step when the time from the application to the firing is not constant from substrate to substrate or when the substrate is not fired immediately after application. The drying is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coated film is not deformed by transporting the substrate or the like. Specifically, it is a method of drying on a hot plate at 50 to 150 ° C, preferably 80 to 120 ° C for 0.5 to 30 minutes, preferably 1 to 5 minutes.

The baking of the substrate coated with the liquid crystal alignment treatment agent can be carried out at any temperature of 100 to 350 캜, preferably 150 to 300 캜, and more preferably 180 to 250 캜. When an amic acid group is present in the liquid crystal alignment treatment agent, the conversion rate of the amic acid to the imide is changed according to the firing temperature, but the liquid crystal alignment treatment agent of the present invention does not necessarily need to be imidized to 100%.

When the thickness of the coated film after firing is too large, the power consumption of the liquid crystal display element is deteriorated. When the thickness of the coated film is too thin, the reliability of the liquid crystal display element may deteriorate. Therefore, the thickness is preferably 10 to 200 nm, more preferably 50 To 100 nm.

Conventional rubbing apparatuses can be used for rubbing the coating film surface formed on the substrate as described above. Examples of the material of the rubbing cloth at this time include cotton, rayon, and nylon

The substrate on which the liquid crystal alignment film obtained by the above method is formed can be used as a liquid crystal display element by producing a liquid crystal cell by a known method. As an example of liquid crystal cell fabrication, a pair of substrates having a liquid crystal alignment film formed thereon is bonded to a substrate having an arbitrary rubbing direction with a rubbing direction of 0 to 270 degrees, preferably with a spacer of 1 to 30 m, more preferably 2 to 10 m, It is common to provide an angle so that the periphery is fixed with a sealant, and a liquid crystal is injected and sealed. The liquid crystal sealing method is not particularly limited, and examples thereof include a vacuum method in which liquid crystal is injected after reducing the pressure in the produced liquid crystal cell, and a dropping method in which a liquid crystal is dropped and sealed.

The liquid crystal display element obtained in this way can be applied to various display devices such as a TN liquid crystal display device, a STN liquid crystal display device, a TFT liquid crystal display device, an OCB liquid crystal display device, further, a transverse electric field liquid crystal display device, .

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not construed as being limited thereto.

(Example 1)

Synthesis of 3,5-diaminobenzyl acetate;

(0.300 mol) of acetic anhydride and 2.4 g (0.030 mol) of pyridine were added to the solution, and the mixture was refluxed for 6 hours in a nitrogen atmosphere .

After confirming disappearance of the raw material spot by TLC (Tin-Layer Chromatography), extraction with ethyl acetate was carried out, and the mixture was washed with pure water to remove acetic anhydride and acetic acid, and then washed with brine and dried with anhydrous magnesium sulfate. Recrystallization was performed using a mixed solvent of ethanol and isopropyl alcohol to obtain milky white crystals (22 g (0.092 mol) of compound of the formula [ii], yield 92%).

Further, 1 H-NMR means a nuclear magnetic resonance spectrum of a hydrogen atom in a molecule.

20.0 g (0.083 mol) of the compound of the formula [ii] was dissolved in 200 ml of 1,4-dioxane, sufficiently deaerated and replaced with nitrogen, 2.0 g of platinum oxide was added, And the reaction was allowed to proceed at room temperature for 24 hours. After completion of the reaction, the platinum oxide was removed by cellite, and the solvent was removed. Then, the reaction mixture was dissolved in methanol, and the mixture was treated with activated charcoal and recrystallized (solvent: ethanol) to obtain a milky white solid (12 g 0.067 mol), yield: 81%).

The abbreviations of the compounds used for the synthesis of polyamic acid and polyimide are as follows.

&Lt; Tetracarboxylic acid dianhydride >

CBDA: 1,2,3,4-Cyclobutane tetracarboxylic acid dianhydride

<Diamine>

DABAc: 3,5-diaminobenzyl acetate

DABBu: 3,5-diaminobenzyl butyrate

DABCPr: 3,5-diaminobenzylcyclopropanecarboxylate

DABCPe: 3,5-diaminobenzylcyclopentanecarboxylate

DABCPP: 3,5-diaminobenzyl-3-cyclopentyl propanoate

DABCHx: 3,5-diaminobenzylcyclohexanecarboxylate

C14DAB: 4-tetradecyloxy-1,3-diaminobenzene

3-ABA: 3-aminobenzylamine

<Organic solvent>

NMP: N-methyl-2-pyrrolidone

? -BL:? -butyrolactone

BC: butyl cellosolve

DPM: dipropylene glycol monomethyl ether

&Lt; Measurement of molecular weight &

The molecular weight of the polyimide obtained by the polymerization reaction was measured by a GPC (room temperature gel permeation chromatography) apparatus, and the number average molecular weight and the weight average molecular weight of the polyimide were calculated as polyethylene glycol and polyethylene oxide conversion values.

GPC apparatus: manufactured by Shodex Corp. (GPC-101)

Column: manufactured by Shodex Co., Ltd. (serial of KD803, KD805)

Column temperature: 50 ° C

Eluent: N, N-dimethylformamide (30 m mol / l of lithium bromide-hydrate (LiBr.H ₂ O) as additive, 30 mmol / l of phosphoric acid anhydrous crystal (o-phosphoric acid) (THF) of 10 ml / l)

* Flow rate: 1.0 ml / min

Standard sample for calibration curve: TSK standard polyethylene oxide (molecular weight about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation and polyethylene glycol (molecular weight about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories.

&Lt; Measurement of imidization rate &

The imidization rate of the polyimide obtained by the polymerization reaction was determined by dissolving the polyimide in d6-DMSO (dimethylsulfoxide-d6), measuring the 1 H-NMR spectrum, and determining the ratio of the remaining amide groups not imidized to the proton And the ratio of the integrated values of the peaks.

&Lt; Production of liquid crystal cell &

Liquid crystal alignment treatment agents prepared in Examples 2 to 7, liquid crystal alignment treatment agents prepared in Examples 13 to 24, and liquid crystal alignment treatment agents prepared in Comparative Examples 1 and 2 were each prepared as follows.

The liquid crystal alignment treatment agent was spin-coated on a glass substrate having a transparent electrode formed thereon, dried on a hot plate at 80 캜 for 5 minutes, and then baked on a hot plate at 210 캜 for 10 minutes to form a coating film having a film thickness of 70 nm. The coated surface was rubbed with a rayon device having a roll diameter of 120 mm at a roll speed of 1000 rpm, a roll advancing speed of 50 mm / sec and a press-in amount of 0.3 mm to obtain a substrate having a liquid crystal alignment film formed thereon . Two sheets of substrates on which liquid crystal alignment films were formed were prepared, spacers having a size of 6 mu m were dispersed on one liquid crystal alignment film surface, a sealant was printed thereon, and another liquid crystal alignment film Followed by curing the sealant to prepare an empty cell. A liquid crystal MLC-2003 (manufactured by Merck Japan Co., Ltd.) was injected into this vacant cell by a reduced pressure injection method and the injection port was sealed to obtain a twisted nematic liquid crystal cell.

Methods of measuring the physical properties and evaluating the properties of each of the manufactured liquid crystal cells are described below.

The results of measurement of the physical properties of each liquid crystal alignment film, evaluation of properties, etc. of each liquid crystal alignment treatment agent in Examples 2 to 7 and Comparative Examples 1 and 2 are summarized in Tables 1 and 2 Respectively. The results of the measurements of the properties of the respective liquid crystal alignment treatment materials, the measurement of the physical properties of the respective liquid crystal alignment films, and the evaluation of properties in Examples 13 to 24 are summarized in Tables 3 and 4.

&Lt; Evaluation of rub resistance &

As a test for rubbing resistance, the surface was rubbed under the condition that the indentation amount was changed to 0.5 mm, and the surface of the film was observed under a strong-focus laser microscope. The evaluation was carried out as follows.

?: No cutting residue or rubbing scratch was observed.

?: Cutting residue or rubbing scratch is observed.

X: The film was peeled off or a rubbing scratch was visually observed.

<Pretilt Angle Measurement>

The prepared twisted nematic liquid crystal cell was heated at 105 DEG C for 5 minutes, and then the measurement of the pretilt angle and the voltage holding ratio were performed. The pretilt angle was measured using a crystal rotation method.

&Lt; Measurement of voltage holding ratio &

The voltage holding ratio of the manufactured twisted nematic liquid crystal cell was measured by applying a voltage of 4 V for 60 seconds at a temperature of 90 DEG C and measuring the voltage after 16.67 ms to determine the degree of voltage retention Respectively. VHR-1 voltage maintenance ratio measuring apparatus manufactured by Toyo Technica Co., Ltd. was used for measurement of the voltage holding ratio.

<Estimation of Accumulated Charge (RDC)>

A DC voltage was applied to the fabricated twisted nematic liquid crystal cell at a temperature of 23 캜 from 0 V to 0.1 V at intervals of 0.1 V to measure a flicker amplitude level at each voltage to prepare a calibration curve. After grounding for 5 minutes, an AC voltage of 3.0 V and a DC voltage of 5.0 V were applied. The flicker amplitude level after 1 hour was measured, and the RDC was estimated by comparing with the previously prepared calibration curve.

(This RDC estimation method is called the Flickr Reference Method)

(Example 2)

The polyamic acid solution (PAA-1) was obtained by reacting 5.00 g (0.025 mol) of CBDA and 4.69 g (0.026 mol) of DABAc as a tetracarboxylic acid dianhydride component in 38.73 g of NMP at room temperature for 16 hours, 1).

10.0 g of the polyamic acid solution (PAA-1) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6 mass%, NMP of 64 mass% and BC of 30 mass% Thereby obtaining a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the above order, and the properties and properties of the liquid crystal cell were measured.

(Example 3)

To 20 g of the polyamic acid solution (PAA-1), 46.67 g of NMP was added and diluted, and 3.29 g of acetic anhydride and 1.40 g of pyridine were added and reacted at 40 ° C for 3 hours to imidize. The reaction solution was cooled to room temperature, and then charged into 250 ml of methanol to recover the precipitated solid matter. This solid was washed several times with methanol, and then dried under reduced pressure at 100 占 폚 to obtain a white powder of polyimide (SPI-1). This polyimide had a number average molecular weight of 12,259 and a weight average molecular weight of 35,793. The imidization rate was 80%.

18 g of NMP was added to 2 g of the obtained polyimide (SPI-1), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. 8.0 g of NMP and 12.0 g of BC were added to this solution and stirred at 50 캜 for 20 hours to obtain a solution containing 5% by mass of polyimide, 65% by mass of NMP and 30% by mass of BC, To obtain an orientation treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 4)

, 6.09 g (0.031 mol) of CBDA as a tetracarboxylic acid dianhydride component, 4.00 g (0.022 mol) of DABAc as a diamine component and 3.04 g (0.01 mol) of C14 DAB as a diamine component were reacted in 74.5 g of NMP at room temperature for 16 hours To obtain a polyamic acid solution (PAA-2).

10.0 g of the polyamic acid solution (PAA-2) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6 mass%, NMP of 64 mass% and BC of 30 mass% Thereby obtaining a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 5)

To 50 g of the polyamic acid solution (PAA-2), 116.67 g of NMP was added and diluted. 7.39 g of acetic anhydride and 3.15 g of pyridine were added and reacted at 50 ° C for 3 hours to imidize.

The reaction solution was cooled to room temperature, and then charged into 1.25 L of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times and then dried under reduced pressure at 100 占 폚 to obtain a white powder of polyimide (SPI-2). This polyimide had a number average molecular weight of 16,321 and a weight average molecular weight of 39,857. The imidization rate was 85%.

18 g of? -BL was added to 2 g of polyimide (SPI-2), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. Further, 8.0 g of? -BL, 6.0 g of BC and 6.0 g of DPM were added to this solution, and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5% by mass of polyimide, 65% by mass of? -BL, 15% by mass of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 6)

(0.033 mol) of CBDA and 4.00 g (0.022 mol) of DABAc as a diamine component, 3.67 g (0.030 mol) of 3-ABA and 7.12 g (0.022 mol) of C14 DAB as tetracarboxylic acid dianhydride components And 116.0 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-3).

10.0 g of the polyamic acid solution (PAA-3) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6 mass%, NMP of 64 mass% and BC of 30 mass% Thereby obtaining a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 7)

To 100 g of the polyamic acid solution (PAA-3), 233.33 g of NMP was added and diluted. 15.66 g of acetic anhydride and 6.67 g of pyridine were added, and the mixture was reacted at 70 캜 for 3 hours to imidize.

The reaction solution was cooled to room temperature, and then charged into 1.25 L of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times and then dried under reduced pressure at 100 ° C to obtain a pale brown powder of polyimide (SPI-3). This polyimide had a number average molecular weight of 18,649 and a weight average molecular weight of 41,774. The imidization rate was 94%.

18 g of? -BL was added to 2 g of polyimide (SPI-3), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. Further, 8.0 g of? -BL, 6.0 g of BC and 6.0 g of DPM were added to this solution, and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5% by mass of polyimide, 65% by mass of? -BL, 15% by mass of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Comparative Example 1)

A mixture of 97.20 g of NMP and 16.5 g (0.046 mol) of 3-ABA as CBDA and 5.56 g (0.046 mol) of 3-ABA as a tetracarboxylic acid dianhydride component and 16 Hour reaction to obtain a polyamic acid solution (PAA-4).

10.0 g of polyamic acid (PAA-4) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6 mass%, NMP of 64 mass% and BC of 30 mass% To obtain an orientation treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Comparative Example 2)

To 50 g of the polyamic acid solution (PAA-4), 116.67 g of NMP was added and diluted. 7.39 g of acetic anhydride and 3.15 g of pyridine were added and the mixture was reacted at 70 ° C for 3 hours to be imidized.

Again, 116.67 g of NMP was added to 50 g of the polyamic acid solution (PAA-4), diluted, and 7.39 g of acetic anhydride and 3.15 g of pyridine were added thereto, and the reaction temperature for imidization was adjusted to 50 캜.

The reaction solution was cooled to room temperature, and then charged into 250 ml of methanol to recover the precipitated solid matter. Further, this solid was washed several times with methanol, and then dried under reduced pressure at 100 占 폚 to obtain a white powder of polyimide (SPI-4). This polyimide had a number average molecular weight of 16,338 and a weight average molecular weight of 39,865. The imidization rate was 80%.

9 g of? -BL was added to 1 g of polyimide (SPI-4), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. 4.0 g of? -BL, 3.0 g of BC and 3.0 g of DPM were added to this solution and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5 mass% of polyimide, 65 mass% of? -BL, 15 mass% of DPM, BC was 15% by mass to obtain a liquid crystal alignment treatment agent to be compared. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 8)

Synthesis of 3,5-diaminobenzylbutylate;

20.0 g (0.100 mol) of 3,5-dinitrobenzyl alcohol and 2.4 g (0.030 mol) of pyridine were dissolved in 200 ml of dehydrated DMF, 11.80 g (0.110 mol) of butyryl chloride was added in an ice bath, Lt; / RTI &gt;

After confirming disappearance of the raw material spot by TLC, the reaction solution was poured into the cooled pure water, and the precipitated solid was filtered and washed with methanol and water. Thereafter, recrystallization was performed using a mixed solvent of ethanol and isopropyl alcohol to obtain milky white crystals (24 g (0.082 mol) of the compound of the formula [iv], yield 82%).

24.0 g (0.082 mol) of the compound of the formula [iv] was dissolved in 200 ml of 1,4-dioxane, sufficiently deaerated and replaced with nitrogen, 2.4 g of platinum / carbon was added, And the reaction was allowed to proceed at room temperature for 24 hours. After completion of the reaction, the platinum / carbon was removed by filtration through Celite, further treated with activated charcoal and then the solvent was removed to obtain a brown viscous substance (12 g (0.058 mol) of compound of the formula [v] %).

(Example 9)

Synthesis of 3,5-diaminobenzylcyclopropanecarboxylate;

20.0 g (0.100 mol) of 3,5-dinitrobenzyl alcohol and 15.7 ml of cyclopropanecarbonyl chloride were dissolved in 200 ml of tetrahydrofuran. 10.0 ml of pyridine was added dropwise thereto, and the mixture was stirred at room temperature for 24 hours. After completion of the reaction, pure water (50 ml) was added and the mixture was stirred for 1 hour. Ethyl acetate was added thereto to extract the solvent, and the extracted organic layer was sequentially washed with 1 N hydrochloric acid, saturated aqueous sodium bicarbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer after washing, and the mixture was dehydrated. After filtration, the solvent was distilled off from the filtrate using a rotary evaporator. The solvent residue was removed by distillation and the residue was recrystallized using isopropyl alcohol to obtain a dinitro compound (24 g (0.090 mol) of the compound of the formula [vi], 90% yield).

20.0 g (0.075 mol) of the compound of the formula [vi] and 2.0 g of platinum oxide were added to 250 ml of 1,4-dioxane, and the mixture was stirred at room temperature under a hydrogen atmosphere. After completion of the reaction, platinum oxide was removed by filtration through Celite, and the solvent was distilled off using a rotary evaporator. After distilling off the solvent, the residue was dissolved in 200 ml of methanol, 2.0 g of activated carbon was added, and the mixture was stirred at room temperature. The activated carbon was removed by Celite filtration, the solvent was distilled off using a rotary evaporator, and the residue was recrystallized from ethyl acetate / hexane = 1/5 to obtain a milky white solid (compound of formula [II] (0.582 mol), yield 78%).

(Example 10)

Synthesis of 3,5-diaminobenzylcyclopentanecarboxylate;

20.0 g (0.100 mol) of 3,5-dinitrobenzyl alcohol and 12.9 ml of cyclopentanecarbonyl chloride were dissolved in 200 ml of tetrahydrofuran. 9.0 ml of pyridine was added dropwise thereto, and the mixture was stirred at room temperature for 22 hours. After completion of the reaction, pure water (50 ml) was added and the mixture was stirred for 1 hour. Ethyl acetate was added thereto to extract the solvent, and the extracted organic layer was sequentially washed with 1 N hydrochloric acid, saturated aqueous sodium bicarbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer after washing, and the mixture was dehydrated. After filtration, the solvent was distilled off from the filtrate using a rotary evaporator. The solvent residue was removed by distillation and the residue was recrystallized using isopropyl alcohol to obtain a dinitro compound (24 g (0.082 mol) of the compound of the formula [II], yield: 82%).

24.0 g (0.082 mol) of the compound of the formula [II] and 2.5 g of platinum / carbon were added to 250 ml of methanol, and the mixture was stirred at room temperature under a hydrogen atmosphere. After completion of the reaction, the platinum / carbon was removed by Celite filtration, and the solvent was distilled off using a rotary evaporator. After distilling off the solvent, the residue was dissolved in 200 ml of methanol, 2.0 g of activated carbon was added, and the mixture was stirred at room temperature. The solvent was distilled off using a rotary evaporator and dried under reduced pressure to obtain a brown liquid (19.3 g (0.082 mol) of a compound of the formula [III], yield: 96%), .

(Example 11)

Synthesis of 3,5-diaminobenzyl 3-cyclopentyl propanoate;

23.1 g (0.117 mol) of 3,5-dinitrobenzyl alcohol and 19.3 ml of 3-cyclopentylpropionyl chloride were dissolved in 250 ml of tetrahydrofuran. 10.3 ml of pyridine was added dropwise thereto, and the mixture was stirred at room temperature for 16 hours. After completion of the reaction, pure water (50 ml) was added and the mixture was stirred for 1 hour. Ethyl acetate was added thereto to extract the solvent, and the extracted organic layer was sequentially washed with 1 N hydrochloric acid, saturated aqueous sodium bicarbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer after washing, and the mixture was dehydrated. After filtration, the solvent was distilled off from the filtrate using a rotary evaporator. The residue after the solvent distillation was recrystallized using hexane / ethyl acetate = 3/1 to obtain a dinitro compound (29.8 g (0.092 mol) of a compound of the formula [X], yield 79%).

29.8 g (0.092 mol) of the compound of the formula [X] and 3.1 g of platinum / carbon were added to 300 ml of methanol, and the mixture was stirred at room temperature under a hydrogen atmosphere. After completion of the reaction, the platinum / carbon was removed by Celite filtration, and the solvent was distilled off using a rotary evaporator. The solvent residue was removed by distillation and the residue was recrystallized using ethyl acetate / hexane = 1/6 to obtain a pale brown solid (21.6 g (0.082 mol) of the compound of the formula [xi], 89% yield).

(Example 12)

Synthesis of 3,5-diaminobenzylcyclohexanecarboxylate;

20.1 g (0.101 mol) of 3,5-dinitrobenzyl alcohol and 14.5 ml of cyclohexanecarbonyl chloride were dissolved in 200 ml of tetrahydrofuran. 9.0 ml of pyridine was added dropwise thereto, and the mixture was stirred at room temperature for 23 hours. After completion of the reaction, pure water (50 ml) was added and the mixture was stirred for 1 hour. Ethyl acetate was added thereto to extract the solvent, and the extracted organic layer was sequentially washed with 1 N hydrochloric acid, saturated aqueous sodium bicarbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer after washing, and the mixture was dehydrated. After filtration, the solvent was distilled off from the filtrate using a rotary evaporator. The solvent residue was removed by distillation and the residue was recrystallized using isopropyl alcohol to obtain a dinitro compound (25.0 g (0.081 mol) of compound of the formula (xii), yield: 81%).

24.8 g (0.081 mol) of the compound of the formula [xii] and 2.5 g of platinum / carbon were added to 250 ml of methanol, and the mixture was stirred under hydrogen atmosphere at room temperature. After completion of the reaction, the platinum / carbon was removed by Celite filtration, and the solvent was distilled off using a rotary evaporator. After distilling off the solvent, the residue was dissolved in 200 ml of methanol, 2.0 g of activated carbon was added, and the mixture was stirred at room temperature. The solvent was distilled off using a rotary evaporator and dried under reduced pressure to obtain a brown liquid (19.3 g (0.078 mol) of the compound of the formula [xiii] (yield: 96%)) .

(Example 13)

7.64 g (0.039 mol) of CBDA as a tetracarboxylic acid dianhydride component, 2.50 g (0.012 mol) of DABBu as a diamine component, 1.95 g (0.016 mol) of 3-ABA and 3.84 g (0.012 mol) And reacted in 63.79 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-5).

10.0 g of polyamic acid solution (PAA-5) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6 mass% of polyamic acid, 64 mass% of NMP and 30 mass% of BC, To obtain a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 14)

To 50 g of the polyamic acid solution (PAA-5), 116.67 g of NMP was added and diluted, and 7.83 g of acetic anhydride and 3.33 g of pyridine were added and reacted at 70 캜 for 3 hours to imidate. The reaction solution was cooled to room temperature, and then charged into 1.25 L of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times and then dried under reduced pressure at 100 ° C to obtain a pale brown powder of polyimide (SPI-5). This polyimide had a number average molecular weight of 16,358 and a weight average molecular weight of 38,735. The imidization rate was 90%.

18 g of? -BL was added to 2 g of polyimide (SPI-5), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. Further, 8.0 g of? -BL, 6.0 g of BC and 6.0 g of DPM were added to this solution, and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5% by mass of polyimide, 65% by mass of? -BL, 15% by mass of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 15)

(PAA-6, manufactured by Nippon Aerosil Co., Ltd.) was reacted in the presence of 5.32 g (0.025 mol) of CBDA as a tetracarboxylic acid dianhydride component and 5.32 g (0.026 mol) of DABCPr as a diamine component in 41.32 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution ).

10.0 g of polyamic acid solution (PAA-6) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6 mass% of polyamic acid, 64 mass% of NMP and 30 mass% of BC, To obtain a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 16)

To 20 g of the polyamic acid solution (PAA-6), 46.67 g of NMP was added and diluted, and 3.06 g of acetic anhydride and 1.31 g of pyridine were added and reacted at 40 ° C for 3 hours to imidate. The reaction solution was cooled to room temperature, and then charged into 250 ml of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times and then dried under reduced pressure at 100 占 폚 to obtain a white powder of polyimide (SPI-6). The polyimide had a number average molecular weight of 13,329 and a weight average molecular weight of 33,233. The imidization rate was 81%.

18.0 g of? -BL was added to 2.00 g of the obtained polyimide (SPI-6), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. 8.0 g of? -BL, 6.00 g of BC and 6.00 g of DPM were added to this solution and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5 mass% of polyimide, 65 mass% of? -BL, 15 mass% of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 17)

5.52 g (0.028 mol) of CBDA as a tetracarboxylic acid dianhydride component, 1.79 g (0.009 mol) of DABCPr as a diamine component, 1.42 g (0.011 mol) of 3-ABA and 2.79 g And 46.1 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-7).

10.0 g of polyamic acid solution (PAA-7) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6 mass% of polyamic acid, 64 mass% of NMP and 30 mass% of BC, To obtain a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 18)

To 40.0 g of the polyamic acid solution (PAA-7), 93.3 g of NMP was added and diluted, and 6.02 g of acetic anhydride and 2.49 g of pyridine were added. And imidized by reacting at 60 ° C for 3 hours. The reaction solution was cooled to room temperature, and then poured into 500 ml of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times, and then dried under reduced pressure at 100 ° C to obtain a white brown powder of polyimide (SPI-7). This polyimide had a number average molecular weight of 17,430 and a weight average molecular weight of 48,532. The imidization rate was 90%.

18.0 g of? -BL was added to 2.00 g of the polyimide (SPI-7), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. 8.00 g of? -BL, 6.00 g of BC and 6.00 g of DPM were added to this solution and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5 mass% of polyimide, 65 mass% of? -BL, 15 mass% of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 19)

5.71 g (0.029 mol) of CBDA as a tetracarboxylic acid dianhydride component, 2.11 g (0.009 mol) of DABCPe as a diamine component, 1.47 g (0.012 mol) of 3-ABA and 2.88 g And 48.7 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-8).

10.0 g of polyamic acid solution (PAA-8) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6 mass% of polyamic acid, 64 mass% of NMP and 30 mass% of BC, To obtain a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 20)

To 40.0 g of the polyamic acid solution (PAA-8), 93.3 g of NMP was added and diluted, and 5.98 g of acetic anhydride and 2.57 g of pyridine were added, and the mixture was reacted at 60 ° C for 3 hours to imidate. The reaction solution was cooled to room temperature, and then poured into 500 ml of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times and then dried under reduced pressure at 100 ° C to obtain a white brown powder of polyimide (SPI-8). This polyimide had a number average molecular weight of 14,757 and a weight average molecular weight of 36,865. The imidization rate was 90%.

18.0 g of? -BL was added to 2.00 g of the polyimide (SPI-8), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. 8.00 g of? -BL, 6.00 g of BC and 6.00 g of DPM were added to this solution and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5 mass% of polyimide, 65 mass% of? -BL, 15 mass% of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 21)

5.71 g (0.029 mol) of CBDA as a tetracarboxylic acid dianhydride component, 2.36 g (0.009 mol) of DABCPP as a diamine component, 1.47 g (0.012 mol) of 3-ABA and 2.88 g And 48.7 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-9).

10.0 g of polyamic acid solution (PAA-9) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6 mass% of polyamic acid, 64 mass% of NMP and 30 mass% of BC, To obtain a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 22)

To 40.0 g of the polyamic acid solution (PAA-9), 93.3 g of NMP was added and diluted, and 5.86 g of acetic anhydride and 2.51 g of pyridine were added and reacted at 60 ° C for 3 hours to imidate. The reaction solution was cooled to room temperature, and then poured into 500 ml of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times, and then dried under reduced pressure at 100 ° C to obtain a white brown powder of polyimide (SPI-9). The polyimide had a number average molecular weight of 14,900 and a weight average molecular weight of 35,161. The imidization rate was 91%.

18.0 g of? -BL was added to 2.00 g of the polyimide (SPI-9), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. 8.00 g of? -BL, 6.00 g of BC and 6.00 g of DPM were added to this solution and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5 mass% of polyimide, 65 mass% of? -BL, 15 mass% of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 23)

5.71 g (0.029 mol) of CBDA as a tetracarboxylic acid dianhydride component, 2.23 g (0.009 mol) of DABCHx as a diamine component, 1.47 g (0.012 mol) of 3-ABA and 2.88 g (0.009 mol) And 49.2 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-10).

10.0 g of the polyamic acid solution (PAA-10) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6 mass% of polyamic acid, 64 mass% of NMP and 30 mass% of BC, To obtain a liquid crystal alignment treatment agent. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

(Example 24)

To 40.0 g of the polyamic acid solution (PAA-10), 93.3 g of NMP was added to dilute the solution, and 5.92 g of acetic anhydride and 2.54 g of pyridine were added and reacted at 60 ° C for 3 hours for imidization. The reaction solution was cooled to room temperature, and then poured into 500 ml of methanol to recover the precipitated solid matter. Further, this solid was washed with methanol several times and then dried under reduced pressure at 100 ° C to obtain a white brown powder of polyimide (SPI-10). The polyimide had a number average molecular weight of 15,864 and a weight average molecular weight of 41,355. The imidization rate was 88%.

18.0 g of? -BL was added to 2.00 g of the polyimide (SPI-10), and the mixture was stirred at 50 占 폚 for 20 hours. At the end of the stirring, the polyimide was completely dissolved. 8.00 g of? -BL, 6.00 g of BC and 6.00 g of DPM were added to this solution and the mixture was stirred at 50 占 폚 for 20 hours to obtain a solution containing 5 mass% of polyimide, 65 mass% of? -BL, 15 mass% of DPM, And BC is 15% by mass to obtain the liquid crystal alignment treatment agent of the present invention. Using this coating liquid, a liquid crystal cell was produced in the same manner as in Example 2, and the properties and properties were evaluated.

From the comparison of Examples 2, 4, 6, 13, 15, 17, 19, 21, and 23 and Comparative Example 1, it was found that a part or all of the diamine component in the liquid crystal alignment treatment agent containing polyamic acid It is understood that the voltage holding ratio of the liquid crystal cell is increased and the accumulation charge when the direct current voltage is applied to the liquid crystal cell is reduced and the rubbing property of the liquid crystal alignment film is also improved. Also, from the comparison of Examples 3, 5, 7, 14, 16, 18, 20, 22 and 24 and Comparative Example 2, it was found that even in the liquid crystal alignment treatment agent containing polyimide, , It can be seen that the same effect can be obtained. From the comparison between Example 4 and Example 6 and Example 5 and Example 7, it was found that the effect of increasing the liquid crystal pretilt angle was enhanced by combining the diamine of the formula [1] and the diamine of the formula [2] Able to know.

With the liquid crystal alignment treatment agent of the present invention, it is possible to obtain an orientation film having a high voltage holding ratio and a small amount of accumulated charge after stopping the application of a direct current voltage. Therefore, the liquid crystal display device manufactured by using the liquid crystal alignment treatment agent of the present invention can be a highly reliable liquid crystal display device, and can be used for TN liquid crystal display device, STN liquid crystal display device, TFT liquid crystal display device, VA liquid crystal display device, An IPS liquid crystal display element, an OCB liquid crystal display element, and the like.

The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2008-158456 filed on June 17, 2008 are hereby incorporated herein by reference as the disclosure of the present specification.

Claims (3)

Diamine of the following formula [1-2].
[Chemical Formula 1]

(Wherein R &lt; ₄ &gt; is a saturated hydrocarbon group having 3 to 8 carbon atoms and containing at least one cyclic structure) A polyamic acid obtained by reacting the diamine-containing diamine component according to claim 1 with a tetracarboxylic acid dianhydride component. A polyimide obtained by imidizing the polyamic acid according to claim 2.