KR101628787B1 - Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal display device, and polymers contained therein - Google Patents

Abstract

[PROBLEMS] To provide a liquid crystal alignment agent which can obtain good pre-tilt characteristics by the photo alignment method, and which does not cause deterioration of display performance even when continuously driven for a long time.
[MEANS FOR SOLVING PROBLEMS] The liquid crystal aligning agent comprises 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride and 2,4,6,8- A tetracarboxylic acid dianhydride containing at least one member selected from the group consisting of [3.3.0] octane-2: 4,6: 8-2 anhydride, and a diamine having a photoreactive structure At least one kind of polymer selected from the group consisting of polyamic acid and polyimide obtained by dehydrocondensing the polyamic acid.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal display element, and a polymer contained therein. BACKGROUND ART [0002]

The present invention relates to a liquid crystal aligning agent. More particularly, the present invention relates to a liquid crystal aligning agent which provides a liquid crystal alignment film with a very suitable performance even by a photo alignment method under a small light irradiation (light irradiation).

Conventionally, as an operation mode of a liquid crystal display device, TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, etc. using liquid crystal molecules having positive dielectric anisotropy, A VA (Vertical Alignment) type using liquid crystal molecules having dielectric anisotropy, and the like are known, and a liquid crystal alignment film mainly composed of an organic film is used for controlling alignment of liquid crystal molecules, respectively (Patent Documents 1 to 4).

The liquid crystal alignment layers in the TN type, the STN type, and the like need to have pre-tilt angular characteristics in order to make the oblique direction constant during liquid crystal driving for the VA type or the like, have. As a method for imparting the pretilt angular characteristic, a rubbing method for the former, a rubbing method for the former, a method for forming protrusions on the surface of the substrate, and the like have been common. Among them, the rubbing method may cause a problem of display failure or circuit breakage due to dust or static electricity generated in the process. On the other hand, a method of forming protrusions on the surface of the substrate is problematic in that when the luminance of the obtained liquid crystal display element is damaged There were all problems, such as.

As a method of giving a pretilt angle instead of these methods, a so-called photo alignment method has been proposed in which ultraviolet rays are irradiated to the photosensitive thin film from an oblique direction with respect to a film normal (see Patent Document 5 and Non-Patent Document 1 ).

In recent years, the liquid crystal display element has been rapidly developed especially for television applications, and has been realized for a long time in comparison with a conventional liquid crystal display element. However, it is known that when the conventionally known liquid crystal display element is continuously driven for a long time, display quality is deteriorated. One of the reasons is thought to be that the liquid crystal alignment film is deteriorated by exposure to light for a long time by driving for a long time. Therefore, in the field of liquid crystal alignment films, materials that do not cause deterioration of display performance even when continuous driving is performed for a long time have been studied.

For example, in Patent Document 6, use of an alignment film material having a crosslinked structure has been proposed. However, even with the technique of the above document, the degree of suppression of display quality deterioration in the case of continuous driving for a long time is not sufficient.

Japanese Laid-Open Patent Publication No. 56-91277 Japanese Unexamined Patent Application Publication No. 1-120528 Japanese Patent Application Laid-Open No. 11-258605 Japanese Patent Application Laid-Open No. 2002-250924 Japanese Patent Application Laid-Open No. 2004-83810 Japanese Patent Application Laid-Open No. 2008-216985 Japanese Laid-Open Patent Publication No. 2010-97188

 J. of the SID 11/3, 2003, p579  T. J. Scheffer et al., J. Appl. Phys. vol. 48, p. 1783 (1977)  F. Nakano et al., JPN. J. Appl. Phys. vol.19, p2013 (1980)

An object of the present invention is to provide a liquid crystal aligning agent which can obtain good pre-tilt characteristics by the photo alignment method and which does not cause deterioration of display performance even when continuously driven for a long time.

According to the present invention,

3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride and 2,4,6,8-tetracarboxybicyclo [3.3.0] , 6: 8-2 anhydride, and a tetracarboxylic acid dianhydride containing at least one member selected from the group consisting of 6:

A liquid crystal aligning agent characterized by containing at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a diamine containing a diamine having a photoreactive structure and a polyimide obtained by dehydrocondylating the polyamic acid .

The liquid crystal aligning agent of the present invention can form a liquid crystal alignment film which does not cause deterioration of display performance even when it is continuously driven for a long time as compared with a liquid crystal aligning agent conventionally known as a liquid crystal aligning agent to which the photo alignment method can be applied have.

Therefore, when the liquid crystal alignment film of the present invention is applied to a liquid crystal display element, the obtained liquid crystal display element is excellent in performance such as its display characteristics and reliability. Therefore, the liquid crystal display element can be effectively applied to various apparatuses and can be suitably used for apparatuses such as a desk calculator, a wrist watch, a desk clock, a coefficient display board, a word processor, a personal computer, a liquid crystal television have.

(Mode for carrying out the invention)

The liquid crystal aligning agent of the present invention, as described above,

3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride and 2,4,6,8-tetracarboxybicyclo [3.3.0] , 6: 8-2 anhydride, and a tetracarboxylic acid dianhydride containing at least one member selected from the group consisting of 6:

(Hereinafter also referred to as " specific polymer ") selected from the group consisting of a polyamic acid obtained by reacting a diamine containing a diamine having a photoreactive structure and a polyimide obtained by dehydrocondensing the polyamic acid do.

≪ Tetracarboxylic acid dianhydride >

The tetracarboxylic acid dianhydride used for synthesizing the polyamic acid in the present invention is 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride and 2, 4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-2 anhydride.

Examples of tetracarboxylic acid dianhydrides used for synthesizing the polyamic acid include 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride and 2,4,6- Tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-2 anhydride in an amount of 80 mol% or more based on the total tetracarboxylic acid dianhydride , And more preferably 90 mol% or more.

As the tetracarboxylic acid dianhydride used for synthesizing the polyamic acid, tetracarboxylic acid dianhydrides other than the above two types can be used in combination. For example, aliphatic tetracarboxylic dianhydrides other than the above two aliphatic tetracarboxylic dianhydrides, alicyclic tetra Carbonic acid dianhydride, aromatic tetracarboxylic acid dianhydride, and the like. Specific examples thereof include aliphatic tetracarboxylic acid dianhydrides such as butanetetracarboxylic dianhydride;

As the alicyclic tetracarboxylic acid dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4, 5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] furan-1,3-dione, , 5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ (Tetrahydrofuran-2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3 ' -Furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetra On;

As the aromatic tetracarboxylic acid dianhydride, for example, pyromellitic dianhydride and the like can be used, and tetracarboxylic acid dianhydride described in Patent Document 7 (Japanese Patent Laid-Open Publication No. 2010-97188) can be used.

<Diamine>

The diamine used for synthesizing the polyamic acid in the present invention is a diamine containing a diamine having a photoreactive structure.

The photoreactive structure is preferably a structure having a function capable of at least one reaction selected from isomerization and dimerization by irradiation of light, -2):

(In the formula (A-2), d is 0 or 1, A ¹ and A ² are each an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, a halogen atom or a cyano group, Quot; are integers of 0 to 4, and &quot; + &quot;

As shown in Fig.

As A ¹ and A ^{2 in the} above formula (A-2), each is preferably an alkoxyl group having 1 to 6 carbon atoms. e and f are each preferably 0.

The diamine having a photoreactive structure preferably has a moiety having a function of orienting liquid crystal molecules. Examples of the photoreactive structure having such a moiety include the following formulas (A-2-1) and A-2-2):

Wherein (A-2-1) and (A-2-2) of, A ^1, A ^2, d, e and f are, respectively, the same meaning as in the formula (A-2),

R ^I and R ^II each represent an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms or a hydrocarbon group having 4 to 30 carbon atoms having an alicyclic structure,

X ^II and X ^III are, respectively, -O-, -CO-, -CO-O- , -O-CO-, -NR-, -NR-CO-, -CO-NR-, -NR-CO- -O-CO-NR-, -NR-CO-NR- or -O-CO-O- wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,

R ^III are, respectively, a methylene group, an arylene group, a divalent alicyclic _{group, -Si (CH 3) 2 -} , and -CH = CH- or -C≡C-, stage ^III R 1 is a hydrogen atom with one or Two or more of them may be substituted with a cyano group, a halogen atom or an alkyl group having 1 to 4 carbon atoms,

h is an integer of 1 to 6,

i is an integer of 0 to 2,

When a plurality of ^XII and ^RIII are present, they may be the same or different from each other,

j is 0 or 1, and

 &Quot; + &quot; indicates a combined hand, respectively)

And at least one structure selected from the structure represented by each of the above-mentioned structures.

Examples of the alkyl group having 1 to 20 carbon atoms for R ^I and R ^II in the formulas (A-2-1) and (A-2-2) include a methyl group, an n-butyl group, -Hexyl group, n-heptyl group, n-octadecyl group and the like. The alkyl group having 1 to 20 carbon atoms for R ^I and R ^II is preferably a straight chain alkyl group having 1 to 12 carbon atoms and preferably a straight chain alkyl group having 3 to 12 carbon atoms from the viewpoint of exhibiting good liquid crystal alignability And particularly preferably a linear alkyl group having from 4 to 12 carbon atoms.

The fluoroalkyl group having 1 to 8 carbon atoms represented by R ^I and R ^II is preferably a straight chain fluoroalkyl group having 3 to 6 carbon atoms from the viewpoint of exhibiting good liquid crystal alignability, N-propyl group, 4,4,4-trifluoro-n-butyl group, 4,4,5,5,5-pentafluoro-n-pentyl group, 4,4,5 , 5,6,6,6-heptafluorohexyl group, and the like.

Specific examples of the hydrocarbon group having 4 to 30 carbon atoms and having an alicyclic structure of R ^I and R ^II include a cyclohexylmethyl group, a cholestanyl group, a cholestenyl group, and a lanostanyl group.

X ^II and X ^III are each preferably -O-.

The diamine having a photoreactive structure may have one or two or more such photo-orientable structures in one molecule, and it is preferable that the diamine has one or two such structures.

Specific examples of the diamine having a photoreactive structure having such a structure include those having a structure represented by the above formula (A-2-1), for example, the following formulas (A-2-1-1) to (A- 1-13):

(A-2-2-1): ???????? (A-2-2-1) ???????? (A-2-2-1) ????????

, And the like.

The diamine may also be represented by the following formulas (A-0) and (A-3):

X ¹ represents a single bond, a methylene group, an alkylene group having 2 or 3 carbon atoms, ^* -O-, ^* -COO-, ^* -OCO-, ^* -X'-R ¹ - ^* -R ¹ -X'- or ^{* -X'-R 1 -X '-} ( stage, X' are, respectively, ⁺ -O-, or -COO- ^{+ +} -OCO- (However, the "+" is (A-0)), R ¹ is an alkylene group having 2 or 3 carbon atoms, and a bonding hand having "*" bonds with a diaminophenyl group ),

Ring ¹ and Ring ² are each independently a cyclohexylene group or a phenylene group,

X "represents a single bond, ⁺ -O-, ⁺ -COO- or ⁺ -OCO- (note that" + "indicates that the bonding hands attached thereto face the left direction of the formula (A-

a is 0 or 1, b is an integer of 0 to 3,

When b is 2 or more, plural X "and Ring ² present may be the same or different from each other, and when a is 0, the leftmost X" of formula (A-0) ,

c is an integer of 0 to 20, and? and? are integers of 0 to 2c + 1, respectively, with? +? = 2c + 1, and when a + b = 0, c is not 0;

(In the formula (A-3), R ^III is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ^IV and R ^V are each independently a hydrogen atom or a methyl group)

At least one kind selected from the group consisting of

Examples of the preferable structure of the compound represented by the above formula (A-0) include a compound represented by the following formula (A-1):

　

(Wherein (A-1), X is ^{I *} -O-, ^* -COO- or ^* -OCO- (Note that this is a combination hand denominated "*" in combination with a diamino phenyl group), a is 0 or 1, b is an integer of 0 to 2, and c is an integer of 1 to 20)

And the like.

As X ^I in the above formula (A-1), it is preferable that ^* -O- or ^* -COO- (provided that the bond with "*" is bonded to a diaminophenyl group) is preferable. Specific examples of the group C _c H _{2c +1} - include a methyl group, an ethyl group, a n-propyl group, an n-butyl group, an n-pentyl group, N-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-octadecyl group, n-hexadecyl group, - nonadecyl group, and n-eicosyl group. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to the other groups.

Specific examples of the compound represented by the above formula (A-1) include compounds represented by the following formulas (A-1-1) to (A-1-4)

And the like.

In the above formula (A-1), it is preferable that a and b do not become 0 at the same time.

In the formula (A-3), each of R ^III , R ^IV and R ^V is preferably a hydrogen atom.

The two amino groups bonded to the benzene ring of the formula (A-3) are preferably in the 2,4-position with respect to the nitrogen atom.

The compound represented by the above formula (A-3) is most preferably N, N-diallyl-2,4-diaminoaniline.

As the diamine used for synthesizing the polyamic acid, a diamine other than the diamine represented by the formulas (A-0) and (A-3) can be used in combination with the diamine having the photoreactive structure, An aliphatic diamine, an alicyclic diamine, an aromatic diamine, a diamino organosiloxane, and the like. Specific examples thereof include aliphatic diamines such as 1,1-meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;

As the alicyclic diamine, for example, 1,4-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;

As aromatic diamines, for example, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl Diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4'-diamino Diphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9- 4,4'- (m-tert-butylphenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, Bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4 Diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3 , 6-diaminocarbazole, N-phenyl-3,6- (4-aminophenyl) -N, N'-dimethylbenzidine, cholestanyloxy-3,5-dia Diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-diaminobenzoic acid lanostanyl, and the like can be used. ;

Examples of the diamino organosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane and the like, and in addition to those described in Patent Document 7 (JP-A-2010-97188) Diamine can be used.

[Composition of diamine]

The diamine used for synthesizing the polyamic acid in the present invention includes a diamine having a photoreactive structure as described above, and is optionally selected from the group consisting of the above formulas (A-0) and (A-3) And at least one kind selected from the group consisting of at least one kind of diamine and other diamines.

The diamine used for synthesizing the polyamic acid in the present invention preferably contains 50 to 99 mol%, more preferably 70 to 95 mol%, of the diamine having a photoreactive structure with respect to the total diamine Gt;

Is preferably 1 to 50 mol%, more preferably 2 to 20 mol%, of at least one diamine selected from the group consisting of the above formulas (A-0) and (A-3) More preferably;

The other diamine can be contained in the range of 20 mol% or less with respect to the total diamine, and further, it can be contained in the range of 10 mol% or less.

The diamine used for synthesizing the polyamic acid in the present invention is a diamine having the photoreactive structure and at least one diamine selected from the group consisting of the above formulas (A-0) and (A-3) .

[Molecular Weight Regulator]

When the polyamic acid is synthesized, a terminal modifier type polymer may be synthesized using a suitable molecular weight modifier together with the tetracarboxylic dianhydride and the diamine as described above. By making such a polymer of the terminal modification type, the coating property (printing property) of the liquid crystal aligning agent can be improved without impairing the effect of the present invention.

Examples of the molecular weight modifier include acid anhydrides, monoamine compounds, and monoisocyanate compounds. Specific examples thereof include acid anhydrides such as maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride My back;

As the monoamine compound, for example, aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine and the like;

Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the total amount of tetracarboxylic acid dianhydride and diamine to be used.

<Synthesis of polyamic acid>

The ratio of the tetracarboxylic acid dianhydride and the diamine to be used in the synthesis reaction of the polyamic acid is preferably such that the amount of the acid anhydride group of the tetracarboxylic acid dianhydride is from 0.2 to 2 equivalents based on 1 equivalent of the amino group of the diamine, Preferably 0.3 to 1.2 equivalents.

The synthesis reaction of the polyamic acid is preferably carried out in an organic solvent at a temperature of preferably -20 ° C to 150 ° C, more preferably 0 to 100 ° C, preferably 0.1 to 120 hours, more preferably 0.5 to 48 hours Time is done.

Examples of the organic solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, Non-protonic polar solvents such as hexamethylphosphoric triamide and hexamethylphosphoric triamide;

phenol solvents such as m-cresol, xylenol, phenol, and halogenated phenol. The amount (a) of the organic solvent used is preferably such that the total amount (b) of the tetracarboxylic acid dianhydride and the diamine is 0.1 to 50 wt% with respect to the total amount (a + b) of the reaction solution.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained.

The reaction solution may be directly supplied to the preparation of the liquid crystal aligning agent. Alternatively, the polyamic acid contained in the reaction solution may be isolated and then supplied to the preparation of the liquid crystal aligning agent, or after the isolated polyamic acid is purified, . When the polyamic acid is subjected to dehydration ring closure to form a polyimide, the reaction solution may be directly supplied to the dehydration ring-closing reaction. Alternatively, the polyamic acid contained in the reaction solution may be isolated and then subjected to dehydration ring- May be purified and then subjected to a dehydration ring-closing reaction. The polyamic acid can be isolated and purified by a known method.

<Synthesis of polyimide>

The polyimide can be obtained by dehydrating and ring closure of the polyamic acid synthesized as described above to imidize it.

The polyimide used in the present invention may be a completely imidized product obtained by dehydrating and ring-closing the entire acid structure of the polyamic acid which is the precursor thereof. The polyimide may be subjected to dehydration ring closure of only a part of the acid structure, It may be an imaged cargo. The imide ratio of the polyimide in the present invention is preferably 30% or more, more preferably 40 to 90%. 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.

The dehydration ring-closure of the polyamic acid is preferably carried out by a method of heating the polyamic acid, or a method of dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and optionally heating . Of these, the latter method is preferable.

In the method of adding the dehydrating agent and the dehydrating ring-closing catalyst to the solution of the polyamic acid, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent to be used is preferably 0.01 to 20 mol based on 1 mol of the acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 mol based on 1 mol of the dehydrating agent to be used. Examples of the organic solvent used in the dehydration ring-closure reaction include the organic solvents exemplified for use in the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 캜, more preferably 10 to 150 캜. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

In this way, a reaction solution containing polyimide is obtained. This reaction solution may be 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. Such a purification operation can be carried out according to a known method.

<Other components>

The liquid crystal alignment film of the present invention contains the above specific polymer as an essential component, but may contain other components as required. Examples of such other components include a polymer other than the specific polymer (hereinafter referred to as "another polymer"), a compound having at least one epoxy group in the molecule (hereinafter referred to as "epoxy compound"), a functional silane compound And the like.

[Other Polymers]

These other polymers can be used for improving solution properties and electrical properties. Such other polymer is a polymer other than the above-mentioned specific polymer, for example, a polyamic acid (hereinafter referred to as &quot; other polyamic acid &quot;) obtained by reacting a tetracarboxylic acid dianhydride and a diamine not containing a diamine having the above- (Hereinafter referred to as &quot; other polyimide &quot;), polyamic acid ester, polyester, polyamide, polysiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly -Phenylmaleimide) derivatives, poly (meth) acrylates, and the like. Of these, other polyamic acids or other polyimides are preferable, and other polyamic acids are more preferable.

The tetracarboxylic acid dianhydride used for synthesizing the above other polyamic acid or other polyimide may be the same as the tetracarboxylic dianhydride used for synthesizing the specific polymer, , 3,4-cyclobutanetetracarboxylic acid dianhydride, and pyromellitic acid dianhydride are preferably used.

Examples of the diamine used for synthesizing the above other polyamic acid or other polyimide include diamines other than the above diamines having a photoreactive structure among the diamines used for synthesizing a specific polymer. Preferably, p-phenylenediamine , 4,4'-diaminodiphenylmethane and 4,4'-diaminodiphenyl ether in an amount of at least 50 mol% based on the total diamine used, More preferably 80 mol% or more.

The proportion of the other polymer to be used is preferably 90% by weight or less, more preferably 50 to 80% by weight, based on the total amount of the polymer (referred to the total amount of the specific polymer and the other polymer,

[Epoxy Compound]

Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, Neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5, Tetraglycidyl-2,4-hexanediol, N, N, N ', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylamino Methyl) cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidyl- Di-aminomethylcyclohexane, and the like. The compounding ratio of these epoxy group-containing compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the total amount of the polymers.

[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, N-benzyl-3-aminopropyltrimethoxysilane, N- 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N -Bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like.

The blending ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the total of the polymers.

<Liquid Crystal Aligner>

The liquid crystal aligning agent of the present invention is constituted by dissolving and incorporating the above-mentioned specific polymer and optionally other additives optionally mixed in an organic solvent.

Examples of the organic solvent usable in the liquid crystal aligning agent of the present invention include the solvents exemplified for use in the synthesis reaction of polyamic acid. In addition, an organic solvent conventionally considered to be a poor solvent for polyamic acid and polyimide can be suitably selected and used in combination. Preferable examples of such an organic solvent include N-methyl-2-pyrrolidone,? -Butyrolactone,? -Butyrolactam, N, N-dimethylformamide, N, N- Methylene-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol diethyl ether, Ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, Isoamyl propionate, isoamyl isobutyrate, diisopentyl ether and the like. These may be used alone or in combination of two or more.

The solid concentration of the liquid crystal aligning agent of the present invention (the ratio of the total weight of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent removed from the organic solvent) is suitably selected in consideration of viscosity, volatility, etc., To 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the surface of the substrate, and the organic solvent is removed to form a coating film which becomes a liquid crystal alignment film. However, when the solid concentration is less than 1 wt%, the film thickness of this coating film becomes too small, On the other hand, when the solid concentration exceeds 10% by weight, the film thickness of the coating film becomes excessively large and it becomes difficult to obtain a satisfactory liquid crystal alignment film in some cases. In addition, the viscosity of the liquid crystal aligning agent is increased So that the coating properties may be deteriorated.

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 the spinner method, the range of 1.5 to 4.5 wt% is particularly preferable. In the case of the printing method, it is particularly preferable that the solid concentration is in the range of 3 to 9 wt%, and thus the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid concentration is in the range of 1 to 5 wt%, and the solution viscosity is in the range of 3 to 15 mPa · s.

&Lt; Method of forming liquid crystal alignment film &

The liquid crystal aligning agent of the present invention can be suitably used for forming a liquid crystal alignment film by a photo alignment method.

As a method of forming the liquid crystal alignment film, for example, a liquid crystal aligning agent is coated on a substrate to form a coating film, and the coating film is irradiated with polarized or unpolarized ultraviolet rays obliquely with respect to the coated film surface, To give a liquid crystal aligning ability to the coating film.

First, the liquid crystal aligning agent of the present invention is applied to the transparent electroconductive film side of the substrate on which the patterned transparent electroconductive film is formed by a suitable application method such as a roll coater method, a spinner method, a printing method, or an ink jet method. After the application, the coated surface is preheated (prebaked) and then baked (post baked) to form a coated film. The prebaking condition is, for example, 0.1 to 5 minutes at 40 to 120 占 폚, and the postbaking condition is preferably 120 to 300 占 폚, more preferably 150 to 250 占 폚, Min, more preferably 10 to 100 minutes. The film thickness of the coated film after post-baking is preferably 0.001 to 1 占 퐉, and more preferably 0.005 to 0.5 占 퐉.

Examples of the substrate include glass such as float glass and soda glass; and transparent substrates made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, and polycarbonate.

As the transparent conductive film, a NESA film made of SnO ₂ , an ITO film made of In ₂ O ₃ -SnO ₂ , or the like can be used. For patterning these transparent conductive films, a photo etching method, a method using a mask when forming a transparent conductive film, and the like are used.

In applying the liquid crystal aligning agent, a functional silane compound, a titanate compound, or the like may be previously coated on the substrate and the transparent conductive film in order to further improve adhesion between the substrate or the transparent conductive film and the coating film.

Subsequently, the coating film is irradiated with ultraviolet rays of polarized light or unpolarized light to give a liquid crystal aligning ability, and the coating film becomes a liquid crystal alignment film. As the radiation, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used, but ultraviolet rays including light having a wavelength of 300 to 400 nm are preferable. When the radiation to be used is polarized (linearly polarized light or partially polarized light), it may be irradiated from a perpendicular direction to the coated film surface or may be irradiated from a tilted direction for giving a pretilt angle. On the other hand, in the case of irradiating non-polarized radiation, it is necessary to conduct irradiation from an inclined direction with respect to the coated film surface.

As the light source of the irradiation radiation, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp and an excimer laser can be used. The ultraviolet ray of the above-mentioned preferable wavelength range can be obtained by a means for using the light source together with a filter, a diffraction grating, or the like.

The irradiation dose of the radiation is preferably 1 J / m 2 or more and less than 10,000 J / m 2, and more preferably 10 to 3,000 J / m 2. Further, when a liquid crystal aligning ability is imparted to a coating film formed from a conventionally known liquid crystal aligning agent by a photo alignment method, a radiation dose of 10,000 J / m 2 or more is required. However, when the liquid crystal aligning agent of the present invention is used, a good liquid crystal aligning ability can be imparted even if the irradiation dose at the time of the photo alignment method is 3,000 J / m2 or less, more preferably 1,000 J / m2 or less, and even 300 J / Thereby contributing to a reduction in the manufacturing cost of the display element.

<Manufacturing Method of Liquid Crystal Display Element>

The liquid crystal display element of the present invention comprises a liquid crystal alignment layer formed of the liquid crystal aligning agent of the present invention. The liquid crystal display element of the present invention can be produced, for example, as follows.

Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal is arranged between the two substrates to manufacture a liquid crystal cell. For example, the following two methods can be used for manufacturing the liquid crystal cell.

The first method is a conventionally known method. First, two substrates are opposed to each other through a gap (cell gap) so that the respective liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded to each other using a sealant. The liquid crystal is injected and filled in the gap, and then the injection hole is sealed, whereby the liquid crystal cell can be manufactured.

The second method is a so-called ODF (One Drop Fill) method. For example, an ultraviolet curable sealant is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed, the liquid crystal is further dropped on the liquid crystal alignment film surface, A liquid crystal cell can be manufactured by bonding one substrate and then curing the sealing agent by irradiating ultraviolet light to the entire surface of the substrate.

In either case, it is preferable to heat the liquid crystal cell to a temperature at which the liquid crystal using the liquid crystal has an isotropic phase, and then gradually cool to room temperature to remove the flow alignment at the time of filling the liquid crystal.

The liquid crystal display element of the present invention can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. Here, when the liquid crystal alignment film is horizontally oriented, by adjusting the angle formed by the polarization direction of the irradiated linearly polarized radiation and the angle between each substrate and the polarizing plate on the two substrates on which the liquid crystal alignment film is formed, the TN type or STN Type liquid crystal cell can be obtained. On the other hand, in the case where the liquid crystal alignment film is vertically aligned, a cell is constituted so that the directions of the easy axis of alignment in the two substrates on which the liquid crystal alignment film is formed are parallel, and the polarizing plate is polarized by 45 , So that a liquid crystal display element having vertically aligned liquid crystal cells can be obtained.

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

As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal and the like can be preferably used.

In the case of a TN type liquid crystal cell or an STN type liquid crystal cell, a nematic liquid crystal having positive dielectric anisotropy is preferable, and examples thereof include biphenyl type liquid crystal, phenyl cyclohexane type liquid crystal, ester type liquid crystal, terphenyl type liquid crystal, A hexane-based liquid crystal, a pyrimidine-based liquid crystal, a dioxane-based liquid crystal, a bicyclooctane-based liquid crystal, a cubane-based liquid crystal, and the like. Further, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonanoate and cholesteryl carbonate, such as C-15 and CB-15 (manufactured by Merck Ltd.) are sold to the liquid crystal And a strong dielectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate may be further added and used.

On the other hand, in the case of a vertically aligned liquid crystal cell, a nematic liquid crystal having a negative dielectric anisotropy is preferable. For example, a dicyanobenzene liquid crystal, a pyridazine liquid crystal, a hept base liquid crystal, Biphenyl-based liquid crystal, phenylcyclohexane-based liquid crystal, and the like.

As the polarizing plate used for the outside of the liquid crystal cell, a polarizing plate in which a polarizing film called &quot; H film &quot; in which iodine is absorbed while polyvinyl alcohol is oriented in a stretched orientation is sandwiched by a cellulose acetate protective film or a polarizing plate made of H film itself have.

The liquid crystal display of the present invention manufactured in this way has excellent display performance and does not deteriorate display performance even when used for a long time.

(Example)

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

The solution viscosity of the polymer and the imidization rate of the polyimide in the following Synthesis Examples were respectively evaluated by the following methods.

[Solution viscosity of polymer]

The solution viscosity (mPa s) of the polymer was measured at 25 캜 using an E-type rotational viscometer for each polymer solution.

[Imidization Rate of Polyimide]

A small amount of the solution containing the polyimide obtained in each of the synthesis examples was fractionated and added to pure water, and the obtained precipitate was separated to isolate the polyimide. The polyimide was sufficiently dried under reduced pressure at room temperature, dissolved in deuterated dimethylsulfoxide, and was determined by the following formula (1) from ¹ H-NMR measured at room temperature using tetramethylsilane as a reference material.

Imidization ratio (%) = (1-A ¹ / A ² × α) × 100 (1)

(In the formula (1), A ¹ is the peak area derived from the proton of the NH group near 10 ppm, A ² is the peak area derived from the other proton, and α is the peak area of the NH 3 group in the polyimide precursor And the ratio of the number of other protons to one proton of the group.

&Lt; Synthesis Examples of Specific Polymers and Comparative Synthesis Examples &

[Synthesis example of polyamic acid]

Synthesis Examples 1 to 42 and Comparative Synthesis Examples 1 to 6

Diamine and tetracarboxylic acid dianhydride as shown in Table 1 were added in this order to 135 g of N-methyl-2-pyrrolidone to prepare a solution. The total weight of the diamine and tetracarboxylic acid dianhydride was then added to the reaction (A-1) to (A-42) and (R-1) to (R-6) were prepared by reacting the polyamic acids 10% by weight, respectively. The viscosity of each solution obtained here is shown in Table 1.

[Synthesis of polyimide]

Synthesis Examples 45 to 67 and Comparative Synthesis Examples 7 to 12

Diamine and tetracarboxylic acid dianhydride of the kind and amount shown in Table 2 were added in this order to 135 g of N-methyl-2-pyrrolidone to dissolve the mixture so that the total weight of the diamine and the tetracarboxylic acid dianhydride was The solution was reacted at 60 캜 for 6 hours to obtain 150 g of a solution containing 10 wt% of polyamic acid, respectively. The viscosity of each solution obtained here is shown in Table 2.

Then, pyridine and acetic anhydride in the amounts shown in Table 2 were added to each of the solutions containing the respective polyamic acids, and the dehydration ring-closure reaction was carried out at 110 占 폚 for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone (by removing pyridine and anhydrous acetic acid used in the dehydration ring-closure reaction in the present operation out of the system) (B-67) and (S-7) to (S-12), respectively. The solution viscosity and the imidization rate of each polyimide measured by diluting the solution to 10 wt% with N-methyl-2-pyrrolidone were measured, .

In the Tables 1 and 2, the abbreviations of the diamine and the tetracarboxylic acid dianhydride are as follows.

[Diamine]

Diamines with photoreactive structure

d-1: The compound represented by the above formula (A-2-1-1)

d-2: Compound represented by the above formula (A-2-1-2)

d-3: Compound represented by the above formula (A-2-1-3)

d-4: Compound represented by the above formula (A-2-1-4)

d-5: Compound represented by the above formula (A-2-2-1)

d-6: Compound represented by the above formula (A-2-1-5)

d-7: Compound represented by the above formula (A-2-1-6)

d-8: Compound represented by the above formula (A-2-1-7)

d-9: Compound represented by the above formula (A-2-1-8)

d-10: Compound represented by the above formula (A-2-1-9)

d-11: Compound represented by the above formula (A-2-1-10)

d-12: Compound represented by the above formula (A-2-1-11)

d-13: Compound represented by the above formula (A-2-1-12)

d-14: Compound represented by the above formula (A-2-1-13)

The diamine represented by the above formula (A-1)

d-15: Compound represented by the above formula (A-1-1)

d-16: Compound represented by the formula (A-1-2)

d-17: Compound represented by the formula (A-1-3)

d-18: Compound represented by the formula (A-1-4)

The diamine represented by the above formula (A-3)

d-19: N, N-diallyl-2,4-diaminoaniline

Other diamines

d-20: 3,5-diaminobenzoic acid cholestanyl

[Tetracarboxylic acid dianhydride]

t-1: 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride

t-2: 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-2 anhydride

t-3: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride

&Lt; Synthesis Example of Other Polymer &

[Synthesis of other polyamic acids]

Synthesis Example OPA-1

98 g (0.50 mol) of 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride and 110 g (0.50 mol) of pyromellitic dianhydride as tetracarboxylic dianhydrides and 4,4'-diaminodiphenylmethane Was dissolved in a mixed solvent consisting of 230 g of N-methyl-2-pyrrolidone and 2,100 g of? -Butyrolactone and reacted at 40 占 폚 for 3 hours. Then, 1,350 g of? -Butyrolactone To obtain a solution containing 10 wt% of polyamic acid (OPA-1). The solution viscosity of this polyamic acid solution was 125 mPa · s.

Synthesis Example OPA-2

200 g (1.0 mol) of 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride as tetracarboxylic dianhydride and 210 g (1.0 mol) of 2,2'-dimethyl-4,4'-diaminobiphenyl ) Was dissolved in a mixed solvent consisting of 370 g of N-methyl-2-pyrrolidone and 3,300 g of? -Butyrolactone, and the reaction was carried out at 40 占 폚 for 3 hours to obtain a polyamic acid (OPA-2) . The solution viscosity of this polyamic acid solution was 160 mPa · s.

Example 1

I. Preparation of liquid crystal aligning agent

The solution containing the polyamic acid (A-1) obtained in Synthesis Example 1 and the solution containing the polyamic acid (OPA-1) obtained in Synthesis Example OPA- (BL), N-methyl-2-pyrrolidone (NMP), and butyl cellosolve (BC) were mixed with the polyamic acid (OPA-1) And the mixture was sufficiently stirred to obtain a solution having a solvent composition of BL: NMP: BC = 30: 20: 50 (weight ratio) and a solid content concentration of 3% by weight. This solution was filtered using a filter having a pore diameter of 1 탆 to prepare a liquid crystal aligning agent.

II. Production of liquid crystal cell

The liquid crystal aligning agent prepared above was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film by a spin coating method and heated on a hot plate at 80 ° C for 1 minute to remove the solvent, (Post-baking) in an oven at 200 deg. C in which the atmosphere had been replaced with nitrogen for 40 minutes to form a coating film having an average film thickness of 1,000 ANGSTROM. Subsequently, polarizing ultraviolet rays 200 J / m &lt; 2 &gt; including a bright line having a wavelength of 313 nm were irradiated from the direction tilted by 40 DEG from the normal to the substrate using a Hg-Xe lamp and a Glane Taylor prism on the surface of this coating film, Thereby forming an alignment film. The same operation was repeated to prepare a pair of substrates (two substrates) each having a liquid crystal alignment film.

An aluminum oxide sphere containing epoxy resin adhesive having a diameter of 5.5 占 퐉 was applied to the periphery of the surface having one liquid crystal alignment film of the above substrates by screen printing and then the liquid crystal alignment film faces of the pair of substrates were arranged face to face, So that the projection direction of the optical axis of ultraviolet rays of each substrate to the substrate surface was inversely parallel, and the adhesive was thermally cured at 150 DEG C for 1 hour. Subsequently, a negative-type liquid crystal (MLC-6608, manufactured by Merck Ltd.) was filled in the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow orientation at the time of injecting the liquid crystal, the liquid crystal cell was heated to 120 DEG C and gradually cooled to room temperature to produce a liquid crystal cell.

The liquid crystal alignability, the pretilt angle and the voltage holding ratio were evaluated for the liquid crystal cell by the following method. The evaluation results are shown in Table 3.

III. Evaluation of Liquid Crystal Cell

(1) Evaluation of liquid crystal alignment property

The presence or absence of an abnormal domain when the voltage of 5 V was turned ON / OFF (applied / released) at 25 캜 was observed by a polarizing microscope, And the orientation was evaluated as &quot; good &quot;.

(2) Evaluation of Pretilt Angle

Non-Patent Document 2 (TJ Scheffer et al., J. Appl. Phys. Vol. 48, p. 1783 (1977)) and Non-Patent Document 3 (F. Nakano, et al., JPN J. Appl. Phys. 2013 (1980)), the pretilt angle was measured by a crystal rotation method using He-Ne laser light.

(3) Evaluation of light resistance

A voltage of 5 V was applied to the liquid crystal cell prepared above at 70 캜 for an application time of 60 microseconds and a span of 167 milliseconds and then the voltage maintenance rate after 167 ms after the application was released was measured VHR-1 &quot; manufactured by Technica (initial voltage holding ratio (VH _IN )). Subsequently, the liquid crystal cell was irradiated with light for 5,000 hours using a weather meter using a carbon arc as a light source, and the voltage maintenance ratio was again measured for the liquid crystal cell after the light irradiation by the same method as described above (VH _AF ).

At this time, when the maintenance rate of the voltage holding ratio ((VH _AF ) / (VH _IN )) was 90% or more, the light resistance was "good", and when it was less than 90%, the light resistance was "poor".

(4) Evaluation of residual DC voltage

A rectangular wave of 30 Hz, 3 V, in which DC 5 V was superimposed on the liquid crystal cell prepared above was applied for 2 hours at an environmental temperature of 60 캜, and the voltage (residual DC Voltage) was obtained by the flicker erase method. This value is an index of the afterimage characteristic. When the value is approximately 150 mV or less, the afterimage characteristic is satisfactory. When the value is approximately 50 mV or less, the afterimage characteristic is particularly excellent.

Examples 2 to 77 and Comparative Examples 1 to 12

A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the polymer of the kind and amount shown in Table 3 was used as the polymer in Example 1, and a liquid crystal cell was produced and evaluated.

The evaluation results are shown in Table 3.

Claims (9)

3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride and 2,4,6,8-tetracarboxybicyclo [3.3.0] , 6: 8-2 anhydride, and a tetracarboxylic acid dianhydride containing at least one member selected from the group consisting of 6:
A diamine comprising a diamine having a photoreactive structure represented by the following formula (A-2)
And a polyimide obtained by subjecting the polyamic acid to dehydration ring-closure. The liquid crystal aligning agent according to claim 1, wherein the liquid crystal aligning agent is at least one selected from the group consisting of:

(In the formula (A-2), d is 0 or 1, A ¹ and A ² are each an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, a halogen atom or a cyano group, Quot; are integers of 0 to 4, and &quot; + &quot; delete The method according to claim 1,
(A-2-1) and (A-2-2): wherein the structure represented by the formula (A-

Wherein (A-2-1) and (A-2-2) of, A ^1, A ^2, d, e and f are, respectively, the same meaning as in the formula (A-2),
R ^I and R ^II each represent an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms or a hydrocarbon group having 4 to 30 carbon atoms having an alicyclic structure,
X ^II and X ^III are, respectively, -O-, -CO-, -CO-O- , -O-CO-, -NR-, -NR-CO-, -CO-NR-, -NR-CO- -O-CO-NR-, -NR-CO-NR- or -O-CO-O- wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
R ^III are, respectively, a methylene group, an arylene group, a divalent alicyclic _{group, -Si (CH 3) 2 -} , and -CH = CH- or -C≡C-, stage ^III R 1 is a hydrogen atom with one or Two or more of them may be substituted with a cyano group, a halogen atom or an alkyl group having 1 to 4 carbon atoms,
h is an integer of 1 to 6,
i is an integer of 0 to 2,
When a plurality of ^XII and ^RIII are present, they may be the same or different from each other,
j is 0 or 1, and
&Quot; + &quot; indicates a combined hand, respectively)
Wherein the liquid crystal aligning agent is at least one structure selected from the group consisting of a structure represented by each of the following formulas. The method according to claim 1,
(A-0) and (A-3): &lt; EMI ID =

X ¹ represents a single bond, a methylene group, an alkylene group having 2 or 3 carbon atoms, ^* -O-, ^* -COO-, ^* -OCO-, ^* -X'-R ¹ - ^* -R ¹ -X'- or ^{* -X'-R 1 -X '-} ( stage, X' are, respectively, ⁺ -O-, or -COO- ^{+ +} -OCO- (However, the "+" is (A-0)), R ¹ is an alkylene group having 2 or 3 carbon atoms, and a bonding hand having "*" bonds with a diaminophenyl group ),
Ring ¹ and Ring ² are each independently a cyclohexylene group or a phenylene group,
X "represents a single bond, ⁺ -O-, ⁺ -COO- or ⁺ -OCO- (provided that" + "indicates that the bonded hands are oriented to the left side of the formula (A-0)
a is 0 or 1, b is an integer of 0 to 3,
When b is 2 or more, plural X "and Ring ² present may be the same or different from each other, and when a is 0, the leftmost X" of formula (A-0) ,
c is an integer of 0 to 20, and? and? are integers of 0 to 2c + 1, respectively, with? +? = 2c + 1, and when a + b = 0, c is not 0;

(In the formula (A-3), R ^III is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ^IV and R ^V are each independently a hydrogen atom or a methyl group)
And a diamine represented by the following general formula (1). The method according to claim 1,
Tetracarboxylic acid dianhydride,
The diamine-free diamine having the photoreactive structure
And at least one polymer selected from the group consisting of a polyamic acid obtained by reacting the polyamic acid and a polyimide obtained by dehydrocondylating the polyamic acid. A liquid crystal alignment film formed by the liquid crystal aligning agent according to any one of claims 1 to 5. A liquid crystal display element comprising the liquid crystal alignment film according to claim 6. 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride and 2,4,6,8-tetracarboxybicyclo [3.3.0] , 6: 8-2 anhydride, and a tetracarboxylic acid dianhydride containing at least one member selected from the group consisting of 6:
A diamine comprising a diamine having a photoreactive structure represented by the following formula (A-2)
Polyamic acid obtained by reacting polyamic acid:

(In the formula (A-2), d is 0 or 1, A ¹ and A ² are each an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, a halogen atom or a cyano group, Quot; are integers of 0 to 4, and &quot; + &quot; A polyimide obtained by subjecting the polyamic acid according to claim 8 to dehydration ring closure.