KR101415544B1 - Liquid crystal aligning agent, liquid crystal alining film and liquid crystal display device - Google Patents

Abstract

[PROBLEMS] To provide a liquid crystal aligning agent for a liquid crystal display element which is excellent in voltage retention rate and long-term reliability, a liquid crystal alignment film formed using the same, and a liquid crystal display element having the same.

[MEANS FOR SOLVING PROBLEMS] A heterocyclic compound having one or two or more oxetane, thianyl, aziridine, and oxazoline structures is added to a polyamic acid and a derivative thereof in an amount of 0.1 to 50 wt% based on the total amount of a polyamic acid and a derivative thereof To prepare a liquid crystal alignment film, and a liquid crystal display device having the liquid crystal alignment film is produced.

Liquid crystal, orientation, oxetane, thiiran, aziridine, oxazoline

Description

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

[TECHNICAL FIELD]

The present invention relates to a heterocyclic compound having at least one heterocyclic structure selected from the group consisting of oxetane, thiirane, aziridine, and oxazoline, and derivatives of polyamic acid and the polyamic acid A liquid crystal aligning agent in which at least one polymer is dissolved in a solvent, a liquid crystal alignment film formed from the liquid crystal aligning agent, and a liquid crystal display device having the same.

BACKGROUND ART [0002]

Liquid crystal display devices are used in various liquid crystal display devices such as monitors of notebook computers and desktop computers, viewfinders of video cameras, projection displays, and the like, and recently, they have become available as televisions. In addition, it is also used as an optoelectronics-related element such as an optical printer head, a high Fourier transform element, and a light valve.

The liquid crystal display element is usually constituted by 1) a pair of substrates arranged opposite to each other, 2) an electrode formed on one or both sides of the opposing surfaces of the pair of substrates, 3) A liquid crystal alignment film formed on the opposite surface, and 4) a liquid crystal layer formed between the pair of substrates.

In a conventional liquid crystal display device, a display device using a nematic liquid crystal is the mainstream, and is composed of 1) twisted nematic (TN) type liquid crystal display device that is twisted by 90 degrees, 2) super twisted nematic (STN) Display devices, and 3) thin film transistor (TFT) type liquid crystal display devices using thin film transistors have been put to practical use. These liquid crystal display devices are disadvantageous in that a viewing angle capable of appropriately visually recognizing an image is narrow and when the liquid crystal display device is viewed from the side, the luminance and contrast are lowered and the luminance inversion is generated in the middle tone.

In recent years, the above-mentioned viewing angle problem has been described as follows: 1) TN-TFT type liquid crystal display device using optical compensation film; 2) VA (vertical alignment) type liquid crystal display device using vertical alignment and optical compensation film; 3) 4) an in-plane switching (IPS) liquid crystal display device of a transverse electric field system, 5) an electrically controlled birefringence (ECB) liquid crystal display device, 6 ) Optically compensated bend (optically compensated bend or optically self-compensated birefringence: OCB) type liquid crystal display device, and an improved technique is put into practical use or examination.

The development of the technology of the liquid crystal display element has been achieved not only by improving the driving method and device structure thereof but also by improving the constituent member used in the liquid crystal display element. Of the constituent members used in the liquid crystal display element, in particular, the liquid crystal alignment film is one of important factors affecting the display quality of the liquid crystal display element, and the role of the liquid crystal alignment film becomes more important as the quality of the liquid crystal display element becomes higher.

The liquid crystal alignment film is prepared from a liquid crystal aligning agent. At present, a liquid crystal aligning agent mainly used is a solution in which a polyamic acid or a soluble polyimide is dissolved in an organic solvent. After applying such a solution to a substrate, a film is formed by means such as heating to form a polyimide alignment film. Various liquid crystal aligning agents have been investigated in addition to polyamic acid. However, most of them have not been put to practical use in view of heat resistance, chemical resistance (liquid resistance), coating property, liquid crystal alignment property, electrical characteristics, optical characteristics and display characteristics.

An important characteristic required for a liquid crystal alignment film for improving the display quality of the liquid crystal display element is the voltage holding ratio. When the voltage holding ratio is low, the voltage applied to the liquid crystal during the frame period is lowered, and as a result, the luminance is lowered, which may hinder normal gradation display. Further, even when the initial voltage holding ratio is high, there is a problem in that the voltage holding ratio (long term reliability) after the high temperature acceleration test is lowered, for example.

In order to solve the above problem, several methods have recently been proposed. 1) a polyamic acid composition comprising a combination of two or more polyamic acids having different physical properties for forming a liquid crystal alignment film is known (see, for example, Patent Documents 1 and 2).

2) A varnish composition containing a polymer component including a polyamic acid and a polyamide and a solvent is known (see, for example, Patent Document 3).

3) Two or more polyamic acid and polyamide having different physical properties and a varnish composition containing a solvent are known (see, for example, Patent Document 4).

4) a varnish composition comprising a polymer material including a polyamic acid synthesized using a diamine compound having a specific structure (see, for example, Patent Document 5).

5) A technique of adding a low molecular weight epoxy resin to a polyimide and a polyamic acid varnish is known (see, for example, Patent Document 6).

However, in these prior arts, the voltage maintenance ratio and the long-term reliability problem still remain to be examined.

Further, a liquid crystal aligning agent containing a curing accelerator having a polyamic acid and an oxazoline structure is known (see, for example, Patent Document 7). However, this curing accelerator is considered to be evaporated, sublimed and decomposed in imidization in the production of a liquid crystal alignment film. In the liquid crystal alignment film produced using such a liquid crystal alignment film, the curing accelerator is preferably added to the electric characteristics The impact has not been examined.

[Patent Document 1] JP-A-11-193345

[Patent Document 2] JP-A-11-193347

[Patent Document 3] International Publication No. 00/61684 pamphlet

[Patent Document 4] International Publication No. 01/000733 pamphlet

[Patent Document 5] JP-A-2002-162630

[Patent Document 6] JP-A-2005-189270

[Patent Document 7] JP-A-9-302225

Considering the above situation, development of a liquid crystal alignment agent for a liquid crystal display element, a liquid crystal alignment layer formed using the liquid crystal display element, and a liquid crystal display element having the improved voltage maintenance ratio and long term reliability has been desired.

[MEANS FOR SOLVING THE PROBLEMS]

The present inventors have repeatedly conducted research to solve the above problems.

As a result, one or more polyamic acids or derivatives thereof obtained by reacting a compound having at least one heterocyclic structure of oxetane, thiane, aziridine, and oxazoline with a tetracarboxylic acid dianhydride and a diamine, It is possible to provide a liquid crystal display device comprising the liquid crystal alignment layer produced using the liquid crystal aligning agent containing the liquid crystal alignment layer with good voltage retention and long term reliability.

In addition, it has been found that by appropriately selecting the polyamic acid, the liquid crystal alignment film produced using the liquid crystal aligning agent can be suitably applied to liquid crystal display devices of various display driving methods.

The present invention has the following configuration.

[1] 1 or 2 or more hetero ring compounds having one or more heterocyclic structures selected from the group consisting of oxetane, thiiran, aziridine, and oxazoline, 1 or 2 selected from polyamic acid and derivatives thereof Wherein the liquid crystal aligning agent contains the heterocyclic compound in an amount of 0.1 to 50% by weight based on the polymer.

[2] The liquid crystal aligning agent according to [1], wherein the heterocyclic compound is a compound having two or more heterocyclic structures.

[3] The liquid crystal aligning agent according to [1] or [2], wherein the heterocyclic compound is a polymer having the heterocyclic structure in the side chain.

[4] The liquid crystal aligning agent according to [3], wherein the polymer is a copolymer.

[5] The liquid crystal aligning agent according to any one of [1] to [4], wherein the polyamic acid is a reaction product obtained by reacting tetracarboxylic dianhydride as an acid component and diamine as an amine component.

[6] The method for producing an aromatic tetracarboxylic acid dianhydride according to [1], wherein the acid component comprises an A component and a B component, and an aromatic tetracarboxylic acid dianhydride is used as an A component of an acid, To (7), and (14). [5] The liquid crystal aligning agent according to [5], wherein the liquid crystal aligning agent is a compound selected from the group consisting of

[7] The liquid crystal aligning agent according to [6], wherein the aromatic tetracarboxylic dianhydride is the compound of the structural formula (1).

[8] The liquid crystal aligning agent according to [6] or [7], wherein either or both of an aliphatic tetracarboxylic acid dianhydride and an alicyclic tetracarboxylic acid dianhydride are used as the B component of the acid.

The aliphatic tetracarboxylic dianhydride and the alicyclic tetracarboxylic dianhydride may be represented by the following structural formulas (19), (23), (25), (35) to (37), (39), 49). [8] The liquid crystal aligning agent according to [8], wherein the liquid crystal aligning agent is a compound selected from the group consisting of

[10] The liquid crystal aligning agent according to [9], wherein the alicyclic tetracarboxylic dianhydride is a compound selected from the group consisting of the structural formulas (19), (23) and (49).

[11] The amine component comprises a diamine represented by a general formula selected from the group consisting of the following general formulas (I) to (VII) as an A component of the amine including an A component and a B component A liquid crystal aligning agent according to any one of [5] to [10].

(I), A ¹ represents - (CH ₂ ) _m -, wherein m represents an integer of 1 to 12. Further, in the general formulas (III), (V) and (VII) in, a ¹ is independently a single bond, -O-, -S-, -SS-, -SO 2 -, -CO-, -CONH-, -NHCO-, -C (CH 3) 2 -, - _{C (CF 3) 2 -,} - (CH 2) m -, -O- (CH 2) m -O-, or -S- (CH _{2) m} represents a -S-, where m is 1 to 12 of an integer addition, in the general formula (VI), a ² are independently a single bond, -O-, -S-, -CO-, -C (CH 3) 2 -., -C (CF 3) ₂ - or represents an alkylene group having 1 to 6 carbon atoms in addition, the general formula (II) ~ hydrogen bonded to the ring claw hexane or benzene ring when in (VII) are, independently, -F, -CH _3, -OH , search _{-COOH, -SO 3 H, -PO 3} H 2, which may be substituted by benzyl or 4-hydroxybenzyl)

The diamine of the component A is represented by the following formulas (IV-1), (IV-2), (IV-15), (IV-16), (V- 33], (VII-1) and (VII-2). [11] The liquid crystal aligning agent according to [11], wherein the liquid crystal aligning agent is selected from the group consisting of

[13] The process according to [11] or [12], wherein a diamine represented by a general formula selected from the group consisting of the following general formulas (VIII) and (IX) to (XII) Liquid crystal aligning agent.

(In the formula (VIII), R ¹ represents a single bond, -O-, -CO-, -COO-, -OCO-, -CONH-, -CH ₂ O-, -CF ₂ O- or (CH ₂ ) _e -, e is an integer of 1 to 6, R ² is a group having a steroid skeleton, a group represented by the general formula (XIII), alkyl having 1 to 30 carbon atoms, or phenyl, 6, the optional -CH ₂ - may be independently replaced with -O- (but not contiguous), -CH = CH- or -C≡C-, and the hydrogen of the phenyl is independently Which may be substituted by fluorine, methyl, methoxy, fluoromethoxy, difluoromethoxy or trifluoromethoxy,

In formula (IX), R ³ is independently hydrogen or methyl; R ⁴ is hydrogen or alkyl having 1 to 30 carbon atoms; R ⁵ is independently a single bond, -CO- or -CH ₂ - and:

In formula (X), R ³ is independently hydrogen or methyl; R ⁴ is hydrogen or alkyl having 1 to 30 carbon atoms; R ⁵ is independently a single bond, -CO- or -CH ₂ -; And R ⁶ and R ⁷ are independently hydrogen, alkyl of 1 to 30 carbon atoms, or phenyl;

In formula (XI), R ⁸ is hydrogen or alkyl having 1 to 30 carbon atoms, and any -CH ₂ - of the alkyl is independently -O- (but not continuous), -CH = CH- Or -C? C-; R ⁹ is independently -O- or alkylene having 1 to 6 carbon atoms; Ring A is 1,4-phenylene or 1,4-cyclohexylene; a is 0 or 1; b is 0, 1 or 2; And c is independently 0 or 1,

In formula (XII), R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms; R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms, or alkyl fluoride having 1 to 30 carbon atoms; R ¹² is independently -O- or alkylene having 1 to 6 carbon atoms; And d is independently 0 or 1)

(In the general formula (XIII), R ¹³ , R ¹⁴ And R ¹⁵ independently represent a single bond, -O-, -COO-, -OCO-, -CONH-, alkylene of 1 to 4 carbon atoms, oxyalkylene of 1 to 3 carbon atoms, or alkylene of 1 to 3 carbon atoms Oxy (with the proviso that oxygen is not continuously bonded); R ¹⁶ and R ¹⁷ are independently hydrogen, fluorine or methyl; R ¹⁸ is selected from the group consisting of hydrogen, fluorine, chlorine, cyano, alkyl of 1 to 30 carbon atoms, alkoxy of 1 to 30 carbon atoms, alkoxyalkyl of 2 to 30 carbon atoms, fluoromethyl, difluoromethyl, trifluoromethyl, Optionally substituted -CH ₂ - in these alkyl, alkoxy and alkoxyalkyl may be substituted by difluoromethylene or a group represented by the general formula (XIV); Ring B and ring C are independently 1,4-phenylene or 1,4-cyclohexylene; f, g and h are independently an integer of 0 to 4; i, j and k are independently an integer of 0 to 3, and the sum thereof is 1 or more; l and m are independently 1 or 2)

(In the general formula (XIV), R ¹⁹ , R ²⁰ , R ²¹ And R ²² are independently alkyl having 1 to 10 carbon atoms, or phenyl, and n is an integer of 1 to 100)

[14] The diamine of the component B is at least one compound selected from the group consisting of the following formulas (VIII-2), (VIII-4), (VIII-5), (VIII-6) XI-6). ≪ 13 > The liquid crystal aligning agent according to < 13 >, wherein the diamine is represented by the general formula:

(Wherein R ²³ is independently an alkyl having 3 to 30 carbon atoms or an alkoxy having 3 to 30 carbon atoms, R ²⁹ is hydrogen or an alkyl group having 1 to 30 carbon atoms, R ³⁰ is hydrogen, 20 < / RTI >

[15] A liquid crystal aligning agent according to any one of [1] to [14], which contains two or more kinds of the above polymers.

The liquid crystal aligning agent according to any one of [1] to [15], further comprising an oxirane compound [16].

[17] A liquid crystal aligning agent containing a heterocyclic compound having one or more heterocyclic structures of thianyl and oxazoline and a polyamic acid or a derivative thereof,

The heterocyclic compound is contained in an amount of 1 to 40% by weight based on the polyamic acid or the derivative thereof,

Wherein the polyamic acid or its derivative is a reaction product obtained by reacting tetracarboxylic dianhydride as an acid component and a diamine as an amine component,

Wherein the tetracarboxylic acid dianhydride is at least one compound selected from the group consisting of the following structural formulas (1), (2), (5) to (7) and (14) As a component, at least one of compounds selected from the group consisting of the following structural formulas (19), (23), (25), (35) to (37), (39), (44) One or both,

The diamine is a compound represented by the following structural formulas (IV-1), (IV-2), (IV-15), (IV-16), (V- (VIII-2), (VIII-4) and (VIII-2) as the B component of the amine, and one or more of the compounds selected from the group consisting of Or one or more of the compounds represented by the general formula selected from the group consisting of (XI-1), (XI-5), (VIII-6) And a liquid crystal alignment agent.

(Wherein R ²³ is independently an alkyl having 3 to 30 carbon atoms or an alkoxy having 3 to 30 carbon atoms, R ²⁹ is hydrogen or an alkyl group having 1 to 30 carbon atoms, R ³⁰ is hydrogen, 20 < / RTI >

(18) The tetracarboxylic dianhydride is selected from the group consisting of the compounds represented by the structural formulas (19), (23) and (49) as the B component of the acid and the compound of the structural formula (V-1), (V-7) and (VII-2) as the A component of the amine, and the diamine is selected from the group consisting of the structural formulas N, N ', N', - tetrakisthienylmethyl-4,4 ', 5'-tetrakisthienylmethyl-4,4'- -Diaminodiphenyl ethane, poly (styrene-co-2-isopropenyl oxazoline), and 1,3-bis (4,5-dihydro-2-oxazolyl) benzene. The liquid crystal aligning agent according to < RTI ID = 0.0 > [17], < / RTI >

Wherein the amine component B is at least one compound selected from the group consisting of compounds represented by the general formulas (VIII-2), (VIII-5), (XI-1), (XI- Wherein the liquid crystal aligning agent is one or two or more of the compounds represented by the formula (1).

[17] The liquid crystal aligning agent according to any one of [17] to [19], further comprising an oxirane compound.

[21] The method according to [20], wherein the oxirane compound is either or both of phenol-dicyclopentadiene resin type epoxy resin and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. ≪ / RTI >

[22] A liquid crystal alignment film formed by firing a liquid crystal aligning agent according to any one of [1] to [21] in a film state.

[23] A liquid crystal display device, comprising: a pair of substrates arranged opposite to each other; an electrode formed on one or both of opposing surfaces of the pair of substrates; and a liquid crystal alignment film And a liquid crystal layer formed between the pair of substrates, wherein the liquid crystal alignment film is a liquid crystal alignment film according to [22].

[Effects of the Invention]

According to the present invention, it is possible to provide liquid crystal display devices of various driving methods with high voltage retention and good long-term reliability.

BEST MODE FOR CARRYING OUT THE INVENTION [

The liquid crystal aligning agent of the present invention is a heterocyclic compound having at least one heterocyclic structure selected from the group consisting of oxetane, thiane, aziridine, and oxazoline, and at least one polyamic acid, Derivatives thereof.

<1. In the heterocyclic compound of the present invention,

The heterocyclic compounds usable in the present invention have one or two or more heterocyclic structures selected from the group consisting of oxetane, thiane, aziridine, and oxazoline. The heterocyclic compound may have only one heterocyclic structure or two or more heterocyclic structures in one compound. The heterocyclic compound may have one heterocyclic structure in one compound, but preferably has two or more heterocyclic structures. The heterocyclic compound may be a polymer having a heterocyclic structure in its side chain, or may be a copolymer. The polymer having a heterocyclic structure in the side chain may be a homopolymer of a monomer having a heterocyclic structure in the side chain, or a copolymer of a monomer having a heterocyclic structure in the side chain and a monomer having no heterocyclic structure. The copolymer having a heterocyclic structure in the side chain may be a copolymer of two or more monomers having a heterocyclic structure in the side chain, or may be a copolymer of two or more monomers having a heterocyclic structure in the side chain and a monomer having no heterocyclic structure It may be merged.

The specific heterocyclic structure has a heteroatom. The reason why the liquid crystal aligning agent containing the specific heterocyclic compound is excellent in voltage retention and long-term stability is unclear. However, it is not clear why the liquid crystal aligning agent containing the specific heterocyclic compound is superior to the specific hetero ring compound . Accordingly, it is preferable that the specific heterocyclic structure is a structure that exists in a specific heterocyclic compound so that the heteroatom in the specific heterocyclic structure and the carbonyl group of the polyamic acid can react with each other.

(Hereinafter, referred to as &quot; oxetane compound &quot;) having a heterocyclic structure mainly containing oxetane (hereinafter referred to as &quot; oxetane compound &quot;), a heterocyclic compound (Hereinafter referred to as "aziridine compound") having mainly aziridine as the structure (hereinafter referred to as "aziridine compound") and a heterocyclic compound (hereinafter referred to as "oxazoline compound") having mainly oxazoline as the heterocyclic structure are polyamic acid It is preferably soluble in a solvent for dissolving the derivative.

Examples of the oxetane compound include EPICLON (trade name, manufactured by Dainippon Ink and Chemicals, Incorporated, bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, bis [ Methyl-phenyl] methane, bis [(3-ethyl-3-oxetanylmethoxy) methyl-phenyl] ether, bis [ (3-ethyl-3-oxetanylmethoxy) methyl-phenyl] sulfone, bis [ Methyl] phenyl] hexafluoropropane, tri [(3-ethyl-3-oxetanylmethoxy) methyl] benzene and tetra [ . In addition to these, oligomers and polymers having oxetanyl can also be mentioned.

Examples of the thiocyanate compound include phenyl glycidyl ether, butyl glycidyl ether, 3,3,3-trifluoromethyl propylene oxide, styrene oxide, hexafluoropropylene oxide, cyclohexene oxide, (Nonafluoro-N-butyl) epoxide, perfluoroethyl glycidyl ether, epichlorohydrin, epibromohydrin, N, N-diglycidyl aniline, and 3- [2- Perfluorohexyl) ethoxy] -1,2-epoxypropane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, poly Propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl Ether, and 3- (N, N-diglycidyl) aminopropyltrimethine N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N'- N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and 3- (N-allyl-N-glycidyl) Cydyl) aminopropyltrimethoxysilane, for example, as described in J. Org. Chem., 28, 229 (1963), and the glycidyl group is converted into an ethylene sulfide group.

Examples of the aziridine compound include 2,4,6-tris (1'-aziridinyl) -1,3,5-triazine, omega-aziridinyl pyropionate-2,2-dihydroxymethyl-butanol tri Ester, 2,4,6-tris (2-methyl-1-aziridinyl) -1,3,5-triazine, 2,4,6-tris , 3-dicarboxylic acid amide, bis (2-ethyl-1-aziridinyl) benzene-1,3-dicarboxylic acid amide, tris 1-aziridinyl) benzene-1,3,5-tricarboxylic acid amide, bis (2-ethyl-1-aziridinyl) sebacic acid amide, 1,6-bis (ethyleneaminocarbonylamino (C2 to C4), and N, N'-bis (4, 6) diisocyanates such as hexane, 2,4-diethylene ureido toluene, 1,1'-carbonyl- -Diethyleneimino-1,3,5-triazin-2-yl) -hexamethylenediamine. In addition to these, oligomers and polymers having aziridinyl may be mentioned.

Examples of the oxazoline compound include 2,2'-bis (2-oxazoline), 1,2,4-tris- (2-oxazolinyl-2) (4,5-dihydro-2-oxazolyl) benzene, 1,3-bis (4,5-dihydro- Bis (4-isopropenyl-2-oxazolin-2-yl) butane, 2,2'- Isopropylidenebis (4-tert-butyl-2-oxazoline), 2,2'-isopropylidenebis (4-phenyl-2-oxazoline) , 2,2'-methylenebis (4-tert-butyl-2-oxazoline), and 2,2'-methylenebis (4-phenyl-2-oxazoline). In addition to these, polymers and oligomers having an oxazolyl such as Epocross (trade name, manufactured by Nippon Printing Co., Ltd.) may be mentioned.

<2. The polymer of the present invention>

The polymer in the present invention is one or two or more polymers selected from polyamic acid and derivatives thereof. Polyamic acid is a reaction product obtained by reacting a tetracarboxylic acid dianhydride as an acid component and a diamine as an amine component. In the present invention, such a polyamic acid can be used.

In addition, the polyamic acid in the present invention may contain a derivative thereof. The derivative of the polyamic acid is a liquid crystal aligning agent which is dissolved in a solvent when it is used as a liquid crystal aligning agent to be described later. When the liquid crystal aligning agent is a liquid crystal alignment film to be described later, it is a component capable of forming a liquid crystal alignment film containing polyimide as a main component. Examples of such polyamic acid derivatives include soluble polyimides, polyamic acid esters, polyamic acid amides, and the like. More specifically, 1) polyimides having a carboxyl dehydration ring-closing reaction with all amino groups of polyamic acid, 2 3) polyamic acid ester converted into carboxyl ester of polyamic acid, 4) part of acid dianhydride contained in tetracarboxylic acid dianhydride compound is substituted with organic dicarboxylic acid and reacted A polyamic acid-polyamide copolymer obtained, and 5) a polyamideimide obtained by subjecting a part or the whole of the polyamic acid-polyamide copolymer to dehydration ring closure reaction.

The polyamic acid and its derivatives can be obtained by reacting a tetracarboxylic dianhydride with a diamine. As the tetracarboxylic acid dianhydride in the present invention, one or more tetracarboxylic dianhydrides are used, but a part of the tetracarboxylic dianhydride may be substituted with a dicarboxylic acid. Here, the ratio of the dicarboxylic acid to the tetracarboxylic acid dianhydride is preferably 10 mol% or less.

The diamine used in the present invention may be one or more diamines, but some diamines may be substituted with monoamines. Here, the ratio of the monoamine to the diamine is preferably 10 mol% or less.

The tetracarboxylic acid dianhydride may be optionally selected, and examples thereof include 1) an aromatic tetracarboxylic acid dianhydride and 2) an aliphatic tetracarboxylic acid dianhydride and an alicyclic tetracarboxylic acid dianhydride Any one kind or two or more kinds is preferable.

On the other hand, in order for the polyamic acid in the present invention to be used as a component of the liquid crystal aligning agent, it is preferable to take a form soluble in a solvent. In order to make the polyamic acid in the present invention as the above-mentioned usable form, it is preferable to appropriately select tetracarboxylic acid dianhydride used as an acid component.

Examples of the aromatic tetracarboxylic dianhydride used as the A component of the acid include acid dianhydrides represented by the following structural formulas (1) to (18). Among the following aromatic tetracarboxylic acid dianhydrides, acid dianhydrides represented by Structural Formulas (1), (2), (5), (6), (7) and (14) Is pyromellitic dianhydride represented by the structural formula (1).

Examples of the aliphatic tetracarboxylic dianhydride or alicyclic tetracarboxylic acid dianhydride used as the component B of the acid include the acid dianhydrides represented by the following structural formulas (19) to (67).

Among the above tetracarboxylic acid dianhydrides, the acid dianhydrides represented by the structural formulas (19) to (39), (44) and (49) , And acid anhydrides represented by formulas (25), (35), (36), (37), (39), (44) ) And (49), and particularly preferred is 1,2,3,4-cyclobutane tetracarboxylic dianhydride represented by the structural formula (19).

The polyamic acid in the present invention can be converted into a polyimide soluble in a solvent by using the structural formulas (24), (35) to (44), (49), (50), (53) It is preferable to use the acid dianhydride to be displayed.

As the tetracarboxylic acid dianhydride in the present invention, the tetracarboxylic acid dianhydrides represented by the structural formulas (1) to (67) may be used singly or in combination of two or more. The aromatic tetracarboxylic acid dianhydride and the alicyclic tetracarboxylic acid dianhydride are produced by using an aromatic tetracarboxylic acid dianhydride, an aliphatic tetracarboxylic acid dianhydride or an alicyclic tetracarboxylic acid dianhydride (particularly preferably pyromellitic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride) The liquid crystal alignment film formed using the liquid crystal aligning agent containing the polyamic acid synthesized from the tetracarboxylic dianhydride in the invention can give a particularly good voltage holding ratio to the liquid crystal display device including the liquid crystal alignment film.

In addition, tetracarboxylic acid dianhydrides other than the tetracarboxylic acid dianhydrides represented by the structural formulas (1) to (67) may be used for the tetracarboxylic dianhydrides in the present invention. Other tetracarboxylic acid dianhydrides are arbitrary, but for example, tetracarboxylic dianhydrides having a branched structure may be used. A liquid crystal alignment film formed using a liquid crystal aligning agent containing a polyamic acid synthesized from a tetracarboxylic dianhydride in the present invention using a tetracarboxylic acid dianhydride having a branched structure can be used as a liquid crystal display The tilt angle can be increased.

The tetracarboxylic dianhydride having a branched structure is not particularly limited, but those having a steroid skeleton represented by the following structural formulas (68) and (69) can be preferably used in the present invention.

On the other hand, the other tetracarboxylic acid dianhydrides which can be used for the tetracarboxylic dianhydrides in the present invention are not limited to the above-mentioned tetracarboxylic dianhydrides, and within the range in which the object of the present invention is achieved, It is needless to say that the tetracarboxylic acid dianhydride in the form of tetracarboxylic dianhydride exists. These additional tetracarboxylic acid dianhydrides may be used singly or in combination of two or more.

Further, a part of the tetracarboxylic acid dianhydride used in the tetracarboxylic acid dianhydride in the present invention may be substituted with a carboxylic acid anhydride. By substituting a part of the tetracarboxylic acid dianhydride with a carboxylic acid anhydride, termination of the polymerization reaction can be caused, and further progress of the reaction can be inhibited, so that the molecular weight of the obtained polymer (polyamic acid) can be easily controlled have. The ratio of the carboxylic acid anhydride to the tetracarboxylic acid dianhydride may be within a range that does not impair the effect of the present invention, but is preferably 10 mol% or less of the total amount of the intended amine.

As described above, the polyamic acid contained in the liquid crystal aligning agent of the present invention is obtained by reacting a tetracarboxylic dianhydride with a diamine.

The above diamines are arbitrarily selected, but preferred are the diamines represented by the general formulas (I) to (VII).

In the general formula (I), A ¹ represents - (CH ₂ ) _m -, wherein m represents an integer of 1 to 12. In the general formulas (III), (V) and (VII), A ¹ independently represents a single bond, -O-, -S-, -SS-, -SO ₂ -, -CO-, -CONH- _{, -NHCO-, -C (CH 3)} 2 -, -C (CF 3) 2 -, - (CH 2) m -, -O- (CH 2) m -O-, or -S- (CH ₂ ) _m- S-, wherein m represents an integer of 1 to 12. In formula (VI), A ² is independently a single bond, -O-, -S-, -CO-, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ - &Lt; / RTI &gt; Further, the general formula (II) ~ hydrogen bonded to the cyclohexane ring or a benzene ring in (VII) are, independently, _{-F, -CH 3, -OH, -COOH} , -SO 3 H, -PO 3 H 2 , Benzyl or 4-hydroxybenzyl.

Examples of the diamine represented by the general formula (I) include diamines represented by the structural formulas (I-1) to (I-4).

Examples of the diamine represented by the general formula (II) include diamines represented by the structural formulas (II-1) and (II-2).

Examples of the diamine represented by the general formula (III) include diamines represented by the structural formulas (III-1) to (III-3).

Examples of the diamine represented by the general formula (IV) include diamines represented by the structural formulas (IV-1) to (IV-16).

Examples of the diamine represented by the general formula (V) include diamines represented by the structural formulas (V-1) to (V-33).

Examples of the diamine represented by the general formula (VI) include diamines represented by the structural formulas (VI-1) to (VI-6).

Examples of the diamine represented by the general formula (VII) include diamines represented by the structural formulas (VII-1) to (VII-16).

Among them, more preferred are the structural formulas (IV-1) to (IV-5), (IV-15), (IV-16), (V- , V-27, V-31, V-33, VI-1, VI-2, VI-6 and VII-1 to VII-5. (IV-2), (IV-15), (IV-16), (V-1) -33), (VII-1), and (VII-2).

The diamines in the present invention may be used alone or in combination of two or more of the diamines represented by the above general formulas (I) to (VII). The molar ratio of the diamines represented by the general formulas (I) to (VII) as the diamines in the present invention corresponds to the diamine structure represented by the general formulas (I) to (VII) , And it is preferably 1 to 100%, more preferably 5 to 80%.

As described above, the diamine used in the present invention may be one or two or more diamines. In particular, a large pretilt angle such as a VA type liquid crystal display device, an OCB type liquid crystal display device, or an STN type liquid crystal display device is required It is preferable to use a diamine having a branched structure.

In the present specification, the diamine having a branched structure means a diamine having a substituent (side chain) capable of expressing a predetermined pretilt angle branching from the main chain when a substituent connecting two amino groups is the main chain. Namely, the diamine having a branched structure can provide a polyamic acid or a polyimide (branched polyamic acid or branched polyimide) having a side chain group for a polymer main chain by reacting with a tetracarboxylic dianhydride. A liquid crystal alignment film formed from a liquid crystal aligning agent containing a polyamic acid or polyimide having a side chain group for such a polymer main chain can increase the pretilt angle in a liquid crystal display element. This is described in, for example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 11-193345).

Therefore, the side chain in the diamine having the branched structure may be appropriately selected in accordance with the required pretilt angle. For example, the side chain is preferably a group having 3 or more carbon atoms. Specifically,

(Cyclohexyl) phenylene which may have a substituent, or an alkyl, alkenyl or alkynyl group having 3 or more carbon atoms, which may have a substituent, a phenyl group which may have a substituent, a cyclohexylphenylene group which may have a substituent,

2) phenyloxy which may have a substituent, cyclohexyloxy which may have a substituent, bis (cyclohexyl) oxy which may have a substituent, phenylcyclohexyloxy which may have a substituent, cyclohexyl which may have a substituent Phenyloxy, or alkyloxy, alkenyloxy or alkynyloxy having 3 or more carbon atoms,

3) phenylcarbonyl, or alkylcarbonyl, alkenylcarbonyl or alkynylcarbonyl having 3 or more carbon atoms,

4) phenylcarbonyloxy, or alkylcarbonyloxy having 3 or more carbon atoms, alkenylcarbonyloxy or alkynylcarbonyloxy,

5) phenyloxycarbonyl which may have a substituent, cyclohexyloxycarbonyl which may have a substituent, bis (cyclohexyl) oxycarbonyl which may have a substituent, bis (cyclohexyl) phenyloxy which may have a substituent Carbonyl, cyclohexylbis (phenyl) oxycarbonyl which may have a substituent, or alkyloxycarbonyl, alkenyloxycarbonyl or alkynyloxycarbonyl having 3 or more carbon atoms,

6) phenylaminocarbonyl, or alkylaminocarbonyl having 3 or more carbon atoms, alkenylaminocarbonyl or alkynylaminocarbonyl,

7) cyclic alkylene having 3 or more carbon atoms,

8) cyclohexylalkylene optionally having substituent (s), phenylalkylene optionally having substituent (s), bis (cyclohexyl) alkylene optionally having substituent (s), cyclohexylphenylalkylene optionally having substituent Bis (cyclohexyl) phenylalkylene, phenylalkyloxy which may have a substituent, alkylphenyloxycarbonyl, or alkylbiphenyloxycarbonyl,

9) phenyl or cyclohexyl substituted by alkyl, fluoro substituted alkyl, or alkoxy,

10) an alkyl, fluorine-substituted alkyl group having two or more benzene rings or cyclohexane rings bonded through a single bond or -O-, -COO-, -OCO-, -CONH- or alkylene having 1 to 3 carbon atoms, , Or a group having a cyclic group substituted by alkoxy, or a group having a steroid skeleton, but the present invention is not limited thereto.

Here, examples of the "substituent" include alkyl, alkoxy, alkoxyalkyl, and the like.

Further, bis (cyclohexyl) or bis (phenyl) may be interrupted by alkylene.

In the present specification, "alkyl", "alkenyl" and "alkynyl" may be linear or branched.

Specific examples of diamines having a branched structure usable in the present invention include diamines represented by the general formulas (VIII) and (IX) to (XII).

In the general formula (VIII), R ¹ represents a single bond, -O-, -CO-, -COO-, -OCO-, -CONH-, -CH ₂ O-, -CF ₂ O- or CH ₂ ) _e -, e is an integer of 1 to 6, R ² is a group having a steroid skeleton, a group represented by the general formula (XIII), an alkyl having 1 to 30 carbon atoms or a phenyl, Is 2 to 6, arbitrary -CH ₂ - may be independently replaced with -O- (but not continuous), -CH═CH- or -C≡C-, and the phenyl The hydrogen may be independently substituted with fluorine, methyl, methoxy, fluoromethoxy, difluoromethoxy or trifluoromethoxy.

In the general formula (IX), R ³ is independently hydrogen or methyl, R ⁴ is hydrogen or alkyl having 1 to 30 carbon atoms, and R ⁵ is independently a single bond, -CO- or -CH ₂ -. In the general formula (X), R ³ is independently hydrogen or methyl, R ⁴ is hydrogen or alkyl having 1 to 30 carbon atoms, R ⁵ is independently a single bond, -CO- or -CH ₂ - And R ⁶ and R ⁷ are independently hydrogen, alkyl of 1 to 30 carbon atoms, or phenyl.

In formula (XI), R ⁸ is hydrogen or alkyl having 1 to 30 carbon atoms, and any -CH ₂ - of the alkyl is independently -O- (but not continuous), -CH = CH- Or -C≡C-, R ⁹ is independently -O- or alkylene having 1 to 6 carbon atoms, ring A is 1,4-phenylene or 1,4-cyclohexylene, a is 0 or 1, b is 0, 1 or 2, and c is independently 0 or 1.

In the general formula (XII), R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms, and R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms, or alkyl fluoride having 1 to 30 carbon atoms , R ¹² is independently -O- or alkylene of 1 to 6 carbon atoms, and d is independently 0 or 1.

In the general formula (XIII), R ¹³ , R ¹⁴ And R ¹⁵ independently represent a single bond, -O-, -COO-, -OCO-, -CONH-, alkylene of 1 to 4 carbon atoms, oxyalkylene of 1 to 3 carbon atoms, or alkylene of 1 to 3 carbon atoms Oxy (with the proviso that oxygen is not continuously bonded); R ¹⁶ and R ¹⁷ are independently hydrogen, fluorine or methyl; R ¹⁸ is selected from the group consisting of hydrogen, fluorine, chlorine, cyano, alkyl of 1 to 30 carbon atoms, alkoxy of 1 to 30 carbon atoms, alkoxyalkyl of 2 to 30 carbon atoms, fluoromethyl, difluoromethyl, trifluoromethyl, Optionally substituted -CH ₂ - in these alkyl, alkoxy and alkoxyalkyl may be substituted by difluoromethylene or a group of the formula (XIV); Ring B and ring C are independently 1,4-phenylene or 1,4-cyclohexylene; f, g and h are independently an integer of 0 to 4; i, j and k are independently an integer of 0 to 3, and the sum thereof is 1 or more; l and m are independently 1 or 2;

In the general formula (XIV), R ¹⁹ , R ²⁰ , R ²¹ And R ²² are independently alkyl of 1 to 10 carbon atoms, or phenyl, and n is an integer of 1 to 100.

Examples of the diamine represented by the general formula (VIII) include diamines represented by the following general formula or structural formulas (VIII-1) to (VIII-43).

In the general formulas (VIII-1) to (VIII-11), R ²³ is preferably an alkyl having 3 to 30 carbon atoms or an alkoxy having 3 to 30 carbon atoms, more preferably an alkyl having 5 to 25 carbon atoms or an alkoxy having 5 to 25 carbon atoms desirable. R ²⁴ is preferably an alkyl having 1 to 30 carbon atoms or an alkoxy having 1 to 30 carbon atoms, more preferably an alkyl having 3 to 25 carbon atoms or an alkoxy having 3 to 25 carbon atoms.

In the general formulas (VIII-12) to (VIII-15), R ²⁵ is preferably alkyl of 4 to 30 carbon atoms, more preferably alkyl of 6 to ²⁵ carbon atoms. In the formulas (VIII-16) and (VIII-17), R ²⁶ is preferably an alkyl having 6 to 30 carbon atoms, more preferably an alkyl having 8 to 25 carbon atoms.

In the general formulas (VIII-18) to (VIII-37), R ²⁷ is preferably an alkyl having 1 to 30 carbon atoms or an alkoxy having 1 to 30 carbon atoms, more preferably an alkyl having 3 to 25 carbon atoms or an alkoxy having 3 to 25 carbon atoms desirable. R ²⁸ is -H, -F, alkoxy, -CN alkyl, of 1 to 30 carbon atoms of 1 to 30 carbon atoms, -OCH ₂ F, -OCHF ₂ or -OCF _3, far preferably from 3 to 25 carbon atoms of the alkyl carbon atoms or More preferably 3 to 25 alkoxy.

Among these, preferred are the diamines represented by the general formulas (VIII-1) to (VIII-11). More preferably, the diamines represented by the general formulas (VIII-2), (VIII-4), (VIII-5) and (VIII-6) are exemplified.

In the general formula (IX), it is preferable that one of the two "NH ₂ -Ph-R ⁵ -O-" is bonded to the third position of the steroid nucleus and the other is bonded to the sixth position. Each of the two amino groups is preferably bonded to the phenyl ring carbon and is bonded to the meta or para to the bonding position of R ⁵ .

Examples of the diamine represented by the general formula (IX) include diamines represented by the structural formulas (IX-1) to (IX-4).

In the general formula (X), the two "NH ₂ - (R ⁷ -) Ph-R ⁵ -O-" are bonded to the carbon of the phenyl ring, Or para of carbon. Further, although the two amino groups are bonded to the phenyl ring carbon, they are preferably bonded to R ⁵ by meta or para.

Examples of the diamine represented by the general formula (X) include diamines represented by the structural formulas (X-1) to (X-8).

In the general formula (XI), each of the two amino groups is bonded to the carbon of the phenyl ring, but is preferably bonded to the meta or para to R ⁹ .

Examples of the diamine represented by the general formula (XI) include diamines represented by the general formulas (XI-1) to (XI-8).

In the general formula (XI-1) ~ (XI -3) of, R ²⁹ is -H, an alkyl group of 1 to 30 carbon atoms are preferable and the general formula (XI-4) ~ (XI -8), R 30 is - H and an alkyl group having 1 to 20 carbon atoms are preferable.

In the general formula (XII), each of the two amino groups is bonded to the carbon of the phenyl ring, but is preferably bonded to the meta or para to R ¹² .

Examples of the diamine represented by the general formula (XII) include diamines represented by the general formulas (XII-1) to (XII-3).

In the general formulas (XII-1) to (XII-3), R ³¹ is preferably an alkyl group having 6 to 20 carbon atoms, and R ³² is preferably -H or an alkyl group having 1 to 10 carbon atoms.

As the diamine in the present invention, the diamines represented by the above general formulas (VIII) to (XII) may be used singly or two or more kinds may be used. The molar ratio of the diamine having a side chain structure in the diamine in the present invention may be adjusted according to the structure of the diamine having the branched structure selected and the predetermined pretilt angle, and is preferably 1 to 100%, more preferably 10 to 100 % Is more preferable.

In addition, as the diamine in the present invention, diamines other than the diamines having the side chain structure represented by the general formulas (I) to (VII) and the general formulas (VIII) to (XII) . These other diamines are optional, but for example, naphthalene diamine having a naphthalene structure, fluorene diamine having a fluorene structure, siloxane diamine having a siloxane bond, or diamines other than the general formulas (VIII) to (XII) And a diamine having a branched structure.

The siloxane-based diamine is not particularly limited, but those expressed by the following general formula (XV) can be preferably used in the present invention.

In the formula (XV), R ³³ And R ³⁴ independently represent alkyl having 1 to 3 carbon atoms or phenyl, and A ³ independently represents methylene, phenylene or alkyl-substituted phenylene. 1 represents an integer of 1 to 6, and m represents an integer of 1 to 10.

In addition, although other diamines are not particularly limited, for example, those represented by the following general formulas (1 ') - (8') can be preferably used in the present invention.

In the general formulas (1 ') - (8'), R ³⁵ and R ³⁶ independently represent an alkyl group having 3 to 30 carbon atoms.

On the other hand, the other diamines other than the general formulas (I) to (XII) used as the diamines in the present invention are not limited to the above diamines, and various diamines Needless to say, it exists. The other diamines may be used singly or in combination of two or more.

The diamine in the present invention can give an appropriate pretilt angle to the liquid crystal alignment film formed using the liquid crystal aligning agent of the present invention by suitably selecting the type of diamine and the combination thereof.

In the case of a VA type liquid crystal display device, a large pretilt angle of about 80 to 90 degrees, in the case of an OCB type liquid crystal display device, a pretilt angle of about 7 to 20 degrees, and a TN type liquid crystal display device or an STN type liquid crystal display device A pretilt angle of about 3 to 10 degrees in the case of an IPS type liquid crystal display device and a small pretilt angle of about 0 to 3 degrees in an IPS type liquid crystal display device are often required. Therefore, the liquid crystal aligning agent of the present invention, which can appropriately adjust the pretilt angle using a diamine having a branched structure, can be applied to any kind of liquid crystal display element.

As described above, a part of the diamine used as a diamine in the present invention may be substituted with a monoamine. By substituting a part of the diamine with a monoamine, the termination of the polymerization reaction can be caused, and further progress of the reaction can be suppressed, so that the molecular weight of the obtained polymer (polyamic acid) can be easily controlled. The ratio of the monoamine to the diamine may be within a range that does not impair the effect of the present invention, but is preferably 10 mol% or less of the total amine as a standard.

It is preferable that the liquid crystal aligning agent of the present invention further contains an oxirane compound from the viewpoint of suppressing the deterioration of the storage characteristics in the liquid crystal display element of the present invention. The oxirane compound is a compound having one or more oxiranyls. The oxirane compound may be a polymer. In the case of a polymer, the oxirane compound may be a homopolymer or a copolymer.

Examples of the oxirane compound include an ether type oxirane compound, an alicyclic group oxirane compound, an ester type oxirane compound, an amine type oxirane compound, a heterocyclic cyclic oxirane compound, a silane type oxirane compound, Containing acrylic compound and the like. As the oxirane compound, one or more of these oxirane compounds may be used.

Examples of commercially available ether type oxirane compounds include epoxy resins such as Epikote 1001, Epikote 1002, Epikote 1003, Epikote 1004, Epikote 1007, Epikote 1009, Epikote 1010 (produced by Yuka Cell Epoxy Co., Ltd.) Coat 807 (manufactured by Yuka Shell Cell Co., Ltd.), Epikron HP-7200HH, Epikron EXA-7260HH (manufactured by Dainippon Ink and Chemicals, Inc.); ERL-4234, ERL-4221, ERL-4206 (manufactured by UCC Co., Ltd.), CY-175, CY-177 and CY-179 (products of CIBA-GEIGY) ); Examples of commercial products of the ester type oxirane compounds include Shodane 508 (manufactured by Showa Denko KK), Aralite CY-182, Aralite CY-192, Aralite CY-184 (manufactured by CIBA-GEIGY) 871, Epikote 872 (produced by Yuka Shell Epoxy Co., Ltd.), ED-5661 and ED-5662 (manufactured by Serraniz Coating Co., Ltd.); Examples of the amine type oxirane compound include tetraglycidyldiaminodiphenylmethane, triglycidyl-para-aminophenol, triglycidyl-meta-aminophenol, diglycidyl aniline, diglycidyl toluidine, tetra Glycidylmethoxylenediamine, diglycidyl tribrom aniline, tetraglycidylbisaminomethylcyclohexane; Examples of commercial products of heterocyclic cyclic oxirane compounds include Aralite PT810 (manufactured by CIBA-GEIGY), Epikote RXE-15 (manufactured by Yuka Shell Epoxy Co., Ltd.), EPITEC (manufactured by Nissan Chemical Industries, Ltd.); Examples of the silane type oxirane compound include (3-glycidoxypropyl) trimethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, 2- (3,4-epoxycyclohexyl) (3-glycidoxypropyl) dimethylethoxysilane, (3-glycidoxypropyl) methyldiethoxysilane, and the like.

Examples of the oxirane compound include phenyl glycidyl ether, butyl glycidyl ether, 3,3,3-trifluoromethyl propylene oxide, styrene oxide, hexafluoropropylene oxide, cyclohexene oxide, N (Nonafluoro-N-butyl) epoxide, perfluoroethyl glycidyl ether, epichlorohydrin, epibromohydrin, N, N-diglycidyl aniline, and Ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol di (ethylene glycol) diglycidyl ether, propylene glycol diglycidyl ether, Glycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneophene T-glycol diglycidyl ether, and 3- (N, N-diglycidyl) N, N ', N'-tetraglycidyl-m-xylylenediamine, 1, 2'-tetradecyldimethoxysilane, 1,3,5,6-tetraglycidyl- , N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and 3- ((N, N-diglycidylaminomethyl) cyclohexane, N-allyl-N-glycidyl) aminopropyltrimethoxysilane, and the like.

The polyamic acid and derivatives thereof in the present invention may have an arbitrary weight average molecular weight. The weight average molecular weight of the polyamic acid and the derivative thereof is not particularly limited, but when it can be used as a component of the liquid crystal aligning agent, it is preferably 5 x 10 ³ or more, more preferably 1 x 10 ⁴ or more. The polyamic acid and its derivatives having a weight average molecular weight of 5 x 10 ³ or more do not evaporate at the step of baking the liquid crystal alignment film and have desirable physical properties as components of the liquid crystal aligning agent.

Here, the weight average molecular weight of the polyamic acid and its derivatives is measured by a gel permeation chromatography (GPC) method. For example, the obtained polyamic acid and derivatives thereof are diluted with dimethylformamide (DMF) to a concentration of about 1% by weight of the polyamic acid, and using DMF (Chromatography Pack C-R7A, manufactured by Shimadzu Corporation) Measured by a gel permeation chromatograph (GPC) method, and converted into polystyrene. In order to proceed with GPC measurement of polyamic acid, polyacrylic acid, and the like with good precision, a developing solvent in which inorganic acid such as phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid, or inorganic salt such as lithium bromide or lithium chloride is dissolved in DMF solvent is prepared .

The polyamic acid and the derivative thereof in the present invention can be produced by a known method. For example, a reaction vessel equipped with a raw material inlet, a nitrogen inlet, a thermometer, a stirrer and a condenser is charged with one or two or more diamines represented by the general formulas (I) to (XII) , And if necessary, a desired amount of monoamine is added.

Subsequently, one or two or more kinds of solvents (for example, N-methyl-2-pyrrolidone or dimethylformamide which is an amide polar solvent) and tetracarboxylic acid dianhydride and, if necessary, carboxylic acid anhydride are added . At this time, the total amount of the tetracarboxylic acid dianhydride is preferably approximately the same molar amount (molar ratio: about 0.9 to 1.1) as the total molar amount of the diamine.

A solution of polyamic acid can be obtained by stirring at 0 to 70 ° C for 1 to 48 hours under stirring. In addition, polyamic acid having a small molecular weight can be obtained by heating to raise the reaction temperature (for example, 50 to 80 캜).

The polyamic acid in the present invention can be identified by precipitating a large amount of a poor solvent, completely separating the solid content and the solvent by filtration, and analyzing by IR and NMR. Further, the solid polyamic acid can be decomposed in a strong alkaline aqueous solution such as KOH or NaOH, extracted with an organic solvent, and then analyzed by GC, HPLC or GC-MS to identify the monomers to be used.

The solution of the obtained polyamic acid may be diluted with a solvent to adjust it to a desired viscosity.

When the polyamic acid in the present invention is a soluble polyimide as a polyamic acid derivative, the polyamic acid solution may be mixed with an acid anhydride such as acetic anhydride, anhydrous pyrophosphoric acid, anhydrous trifluoroacetic acid, Imidization reaction at a temperature of 20 to 150 캜 together with a tertiary amine such as triethylamine, pyridine or collidine.

Alternatively, a polyamic acid may be precipitated by using a large amount of a poor solvent (an alcohol solvent such as methanol, ethanol, isopropanol, or a glycol solvent) with a polyamic acid solution, and the precipitated polyamic acid may be recovered in a solvent such as toluene, Or may be obtained by imidization reaction at a temperature of 20 to 150 DEG C together with the same dehydrating agent and dehydration ring-closing catalyst.

In the imidization reaction, the ratio of the dehydrating agent to the dehydration cyclization catalyst is preferably 0.1 to 10 (molar ratio). It is preferable that the total amount of both is 1.5 to 10 times as much as the total molar amount of the acid dianhydride contained in the tetracarboxylic acid dianhydride to be used. By adjusting the dehydrating agent, the catalyst amount, the reaction temperature and the reaction time of the chemical imidization, the degree of imidization can be controlled to obtain the partial polyimide.

The obtained partial polyimide may be separated from the solvent and may be used as a liquid crystal aligning agent by redissolving it with the above-mentioned heterocyclic compound in a solvent described later or may be used as a liquid crystal aligning agent without being separated from a solvent, May also be used.

As described above, a part of the acid dianhydride used as the tetracarboxylic acid dianhydride in the present invention may be substituted with an organic dicarboxylic acid. Polyamic acid-polyamide copolymers can be obtained by preparing the polyamic acid in the present invention using organic dicarboxylic acid and tetracarboxylic dianhydride. Here, the ratio of the organic dicarboxylic acid to the tetracarboxylic acid dianhydride may be within a range that does not impair the effect of the present invention, but is preferably 10 mol% or less as a standard.

In addition, polyamideimide can be prepared by chemically imidizing the polyamic acid-polyamide copolymer.

<3. The liquid crystal aligning agent of the present invention &

The liquid crystal aligning agent of the present invention includes the above heterocyclic compound, the above-mentioned polyamic acid according to the present invention, and derivatives thereof. The liquid crystal aligning agent of the present invention may further contain a solvent from the viewpoints of adjustment of properties such as viscosity, ease of handling, and simplification of the process, and further includes various additives contained in usual liquid crystal aligning agents .

The content of the heterocyclic compound in the liquid crystal aligning agent is preferably 0.1 to 50% by weight, more preferably 1 to 40% by weight, based on the weight of the polyamic acid and the derivative thereof in the liquid crystal aligning agent, And more preferably 1 to 20% by weight from the viewpoint of long-term stability of electrical characteristics when used in a liquid crystal display device.

The content of the heterocyclic structure in the liquid crystal aligning agent in the heterocyclic compound differs depending on the kind of the heterocyclic structure. The content of the oxetane compound in the liquid crystal aligning agent is preferably 0.1 to 40% by weight based on the polyamic acid and the derivative thereof when the oxetane structure in the oxetane compound is converted into oxetane. The content of the thioran compound in the liquid crystal aligning agent is preferably 0.1 to 40% by weight based on the amount of the polyamic acid and the derivative thereof in terms of thiane structure in thiane compound. The content of the aziridine compound in the liquid crystal aligning agent is preferably 0.1 to 40% by weight based on the polyamic acid and the derivative thereof when the aziridine structure in the aziridine compound is converted to aziridine. The content of the oxazoline compound in the liquid crystal aligning agent is preferably 0.1 to 40% by weight based on the amount of the polyamic acid and the derivative thereof when the oxazoline structure in the oxazoline compound is converted to oxazoline.

On the other hand, when two or more heterocyclic structures are included in the heterocyclic compound, the content of the heterocyclic structure in the liquid crystal aligning agent can be determined according to the ratio of the respective heterocyclic structures in the heterocyclic compound.

The content of the oxirane compound in the liquid crystal aligning agent of the present invention is 1 to 20 wt% based on the amount of the polyamic acid and the derivative thereof in terms of oxirane, and the content of the oxirane compound in the liquid crystal aligning agent .

As the polyamic acid and the derivative thereof in the present invention, the above-mentioned polyamic acid and a derivative thereof can be used. For example, in the case of polyamic acid, a polyamic acid obtained by reacting the A component or B component of the above acid with the A component or B component of the amine, a polyamic acid obtained by reacting the A component and B component of the acid with the A component or B component of the amine , A polyamic acid obtained by reacting the A component or B component of the above acid with the A component and the B component of the amine, and the polyamic acid obtained by reacting the A component and the B component of the acid with the A component and the B component of the amine And polyamic acid to be obtained, and the like.

The content of the polyamic acid and the derivative thereof in the liquid crystal aligning agent of the present invention can be appropriately selected according to the application method of the liquid crystal aligning agent to the substrate. For example, polyamic acid and its derivatives in a liquid crystal aligning agent used in a printing machine (including an offset machine and an inkjet printing machine, hereinafter abbreviated as &quot; printing machine &quot;) usable in a manufacturing process of a liquid crystal display element The content is preferably 0.5 to 30 wt%, more preferably 1 to 15 wt%, based on the total amount, but is appropriately adjusted in accordance with the viscosity of the liquid crystal aligning agent (described later).

The solvent that can be used in the present invention widely includes a solvent commonly used as a production process or an application of a polymer component such as a polyamic acid, a soluble polyimide, and a polyamideimide, and may be appropriately selected depending on the purpose of use. The solvent may be selected from the group consisting of 1) an aprotic polar organic solvent which is easily soluble in polyamic acid or soluble polyimide, 2) a mixed solvent containing a solvent for changing the surface tension to improve the coating property, .

These solvents are exemplified as follows.

1) A non-protonic polar organic solvent (hereinafter, aprotic polar organic solvent) which is a two-solvent type for polyamic acid or soluble polyimide such as N-methyl-2-pyrrolidone, dimethylimidazolidinone, N -Methylcaprolactam, N-methylpropionamide, N, N-dimethylacetamide, dimethylsulfoxide, N, N-dimethylformamide, N, N-diethylformamide, diethylacetamide, , gamma -valerolactone. Of these, N-methyl-2-pyrrolidone, dimethylimidazolidinone,? -Butyrolactone,? -Valerolactone and the like are more preferable examples.

2) Solvents (hereinafter, other solvents) for the purpose of improving the coating properties by changing the surface tension: alkyl such as alkyl lactate, 3-methyl-3-methoxybutanol, tetralin, isophorone, Diethylene glycol monoalkyl ether such as diethylene glycol monoethyl ether, ethylene glycol monoalkyl or phenylacetate, triethylene glycol monoalkyl ether, propylene glycol monobutyl ether and the like, ethylene glycol monoalkyl ether such as ethylene glycol monobutyl ether, Dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, ester compounds such as acetate, and the like. Of these, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether and the like are more preferable examples.

The types and ratios of the aprotic polar solvent and other solvents can be appropriately set in consideration of the printing property, coating property, solubility, storage stability, and the like of the liquid crystal aligning agent. The aprotic polar solvent is more excellent in solubility and storage stability than other solvents, and other solvents tend to be excellent in printability and applicability.

As described above, the liquid crystal aligning agent of the present invention may contain various additives. As the various additives, a polymer compound other than the polyamic acid and the derivative thereof, or a low-molecular compound may be selected depending on the purpose.

For example, a polymer compound soluble in an organic solvent may be used as an additive. By adding them, electrical characteristics and orientation of the liquid crystal alignment film to be formed can be controlled. Examples of the polymer compound include polyamides, polyurethanes, polyureas, polyesters, polyepoxides, polyester polyols, silicone-modified polyurethanes and silicone-modified polyesters.

Examples of the additive for the low molecular weight compound include 1) an antistatic agent when it is required to improve the antistatic property, 2) an antistatic agent when it is necessary to improve the antistatic property, 3) A silane coupling agent and a titanium-based coupling agent may be used, and (4) an imidization catalyst may be used when the imidization is carried out at a low temperature.

Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) Aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, Propyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyl 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N- (1,3-dimethylbutylidene) -3- ( Triethoxysilyl) -1-propylamine, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine It can be given.

Examples of the imidization catalyst include aliphatic amines such as trimethylamine, triethylamine, tripropylamine and tributylamine; Aromatic amines such as N, N-dimethylaniline, N, N-diethylaniline, methyl-substituted aniline, and hydroxy-substituted aniline; Substituted substituted isoquinoline, substituted isoquinoline, hydroxy substituted isoquinoline, imidazole, methyl substituted imidazole, hydroxy substituted imidazole, and the like can be used. Of cyclic amines are preferably added. Particularly, it is preferable to use N, N-dimethylaniline, o-hydroxyaniline, m-hydroxyaniline, p-hydroxyaniline, o-hydroxypyridine, m-hydroxypyridine, p-hydroxypyridine, .

The addition amount of the silane coupling agent is usually 0 to 10% by weight, preferably 0.1 to 3% by weight, based on the total weight of the polymer.

The addition amount of the imidation catalyst is usually 0.01 to 5 equivalents, preferably 0.05 to 3 equivalents, relative to the carbonyl group of the polyamic acid and the derivative thereof.

The amount of other additives to be added varies depending on the use, but is usually 0 to 30% by weight, preferably 0.1 to 10% by weight, based on the total weight of the polyamic acid and the derivative thereof.

The viscosity of the liquid crystal aligning agent of the present invention varies depending on the application method, the concentration of the polyamic acid and the derivative thereof, the kind of the polyamic acid and the derivative thereof to be used, and the kind and ratio of the solvent. For example, in the case of application by a printing machine, it is preferably 5 to 100 mPa · s (more preferably 10 to 80 mPa · s). If it is less than 5 mPa · s, it is difficult to obtain a sufficient film thickness, and if it exceeds 100 mPa · s, printing unevenness may be large. In the case of coating by spin coating, 5 to 200 mPa · s (more preferably 10 to 100 mPa · s) is suitable.

The viscosity of the liquid crystal aligning agent is measured by a rotational viscosity measurement method and measured (measured temperature: 25 ° C) using, for example, a rotational viscometer (TVE-20L type manufactured by Toki Industry Co., Ltd.).

Another preferred embodiment of the liquid crystal aligning agent of the present invention is a composition comprising two or more kinds of polyamic acid and a derivative thereof. For example, a polyamic acid or a derivative thereof obtained by reacting a tetracarboxylic acid dianhydride and a diamine having no branched structure with a liquid crystal aligning agent containing two types of polyamic acid is referred to as polyamic acid I, and a tetracarboxylic acid dianhydride and a side chain structure Is a polyamic acid II, the composition of polyamic acid I and polyamic acid II is prepared by mixing the above-mentioned polyamic acid I and polyamic acid II. A liquid crystal alignment film formed using a liquid crystal aligning agent containing polyamic acid I can give a good voltage holding ratio to a liquid crystal display device including the liquid crystal alignment film. A liquid crystal alignment film formed using a liquid crystal aligning agent containing polyamic acid II can give an appropriate pretilt angle to a liquid crystal display element containing the liquid crystal alignment film.

The weight ratio of the polyamic acid I and the polyamic acid II to be mixed is preferably I / II = 99 / 1-50 / 50 and more preferably I / II = 95 / 5-80 / 20. The weight ratio may be appropriately adjusted, for example, according to the required pretilt angle, and the pretilt angle can be increased by increasing the proportion of polyamic acid II. As described above, in the present invention, it is also possible to impart desirable characteristics as the liquid crystal aligning agent of the present invention by containing (mixing) two or more kinds of the above polymers.

<4. The liquid crystal alignment film of the present invention>

The liquid crystal alignment film of the present invention is a liquid crystal alignment film formed by firing the above-mentioned polyamic acid in the liquid crystal aligning agent of the present invention in the film state of the liquid crystal aligning agent of the present invention.

The liquid crystal alignment film may be formed by applying the liquid crystal aligning agent of the present invention to a substrate for a liquid crystal display element or a substrate for measurement such as calcium fluoride or silicon and coating the film of the liquid crystal aligning agent at a temperature of, Preferably 180 to 280 占 폚. Here, the film thickness of the liquid crystal alignment film is preferably 10 to 300 nm, more preferably 30 to 100 nm. Further, it is preferable that the liquid crystal alignment film is rubbed.

The film thickness of the liquid crystal alignment film can be adjusted by the viscosity of the liquid crystal aligning agent or the application method of the liquid crystal aligning agent. The film thickness of the liquid crystal alignment film can be measured by a known film thickness measuring device such as a step difference meter or an ellipsometer. Furthermore, the components in the liquid crystal alignment film can be subjected to a treatment such as hydrolysis, if necessary, and analyzed using ordinary analytical means such as IR and MS.

<5. The liquid crystal display element of the present invention &

The liquid crystal display element of the present invention is a liquid crystal display element comprising: 1) a pair of substrates disposed opposite to each other; 2) a liquid crystal alignment film of the present invention formed on the opposing surface of each of the pair of substrates; and 3) And a liquid crystal layer.

The pair of oppositely disposed electrode-attached substrates are preferably transparent substrates (for example, glass substrates).

An electrode is formed on the surface of at least one or both substrates of the pair of substrates in accordance with the shape of the liquid crystal display element. The electrode is not particularly limited as long as it is an electrode formed on one surface of the substrate. Examples of such electrodes include a vapor-deposited film of ITO or metal. The electrode may be formed entirely on the surface of the substrate, or may be formed in a predetermined pattern, for example. On the substrate on which no electrode is formed, the liquid crystal alignment film of the present invention is formed on the surface of the substrate. On the substrate on which the electrode is formed, the liquid crystal alignment film of the present invention is formed on the electrode. Formation of the liquid crystal alignment film of the present invention is as described above.

The liquid crystal layer sandwiched between the pair of substrates includes a liquid crystal composition. Here, the liquid crystal composition is not particularly limited, and any composition may be used, depending on the driving mode, such as a liquid crystal composition having a positive dielectric anisotropy and a liquid crystal composition having a negative dielectric anisotropy.

Examples of preferable liquid crystal compositions having a positive dielectric anisotropy include those disclosed in Japanese Patent No. 3086228, Japanese Patent No. 2635435, Japanese Patent Application Laid-Open Nos. 5-501735, 8-157826, 8-231960, 9-241644 (EP885272A1), JP-A No. 9-302346 (EP806466A1), JP-A No. 8-199168 (EP722998A1), JP-A No. 9-235552, JP-A No. 9-255956, Japanese Patent Application Laid-Open No. 241643 (EP885271A1), Japanese Patent Application Laid-Open No. 10-204016 (EP844229A1), Japanese Patent Application Laid-Open No. 10-204436, Japanese Patent Application Laid-Open Nos. 10-231482, 2000-087040, 2001-48822 .

As the liquid crystal composition usable in VA type liquid crystal display elements, various liquid crystal compositions having a negative dielectric anisotropy can also be used. Examples of preferable liquid crystal compositions are disclosed in Japanese Patent Application Laid-Open Nos. 57-114532, 57-2425, 64-24865, 64-10386, 68-104869, -168076, JP-A-10-168453, JP-A-10-236989, JP-A-10-236990, JP-A-10-236992, JP-A-10-236993, JP-A-10-236994 10-237000, 10-237004, 10-237024, 10-237035, 10-237075, and 10-237076, the disclosures of which are incorporated herein by reference. 10-237448 (EP967261A1), 10-287874, 10-287875, 10-291945, 11-029581, and 11-080049 Open Publication Nos. 2000-256307, 2001-019965, 2001-072626, 2001-192657, etc.

One or more optically active compounds may be added to the liquid crystal composition in which the dielectric anisotropy is positive or negative.

The liquid crystal display element of the present invention may, of course, also have other members.

For example, in a TFT type liquid crystal device of color display using a thin film transistor, a thin film transistor, an insulating film, a protective film, a signal electrode, a pixel electrode and the like are formed on a first transparent substrate, A black matrix for blocking light, a color filter, a flattening film, a pixel electrode, and the like.

In VA-type liquid crystal display elements, in particular MVA-type liquid crystal display elements, fine protrusions called domains are formed on the first transparent substrate. In addition, a spacer may be formed to adjust the cell gap between the substrates.

The liquid crystal display element of the present invention can be manufactured by any method, for example, 1) a step of applying a liquid crystal aligning agent onto the two transparent substrates, 2) a step of drying the applied liquid crystal aligning agent, 3) A step of subjecting the obtained liquid crystal aligning agent to a heat treatment necessary for dewatering and cycling reaction, 4) a step of orienting the obtained alignment film, 5) a step of sealing the liquid crystal between the substrates after the two substrates are bonded, Or a method of dropping liquid crystal on one substrate and then sticking to the other substrate.

As a coating method in the step of applying the liquid crystal aligning agent, a spinner method, a printing method, a dipping method, a dropping method, an ink jet method, and the like are generally known. These methods are also applicable to the present invention.

In addition, as a method of carrying out the heating step required for the drying step and the dehydration reaction, a method of heating in an oven or an infrared, a method of heating on a hot plate, and the like are generally known. These methods are also applicable to the present invention. The drying process is preferably performed at a relatively low temperature (50 to 140 캜) within a range in which evaporation of the solvent is possible. The heat treatment is preferably carried out at a temperature of about 150 to 300 캜.

In the alignment treatment for the liquid crystal alignment film, the rubbing treatment is usually performed in the IPS type liquid crystal display device, the OCB type liquid crystal display device, the TN type liquid crystal display device, and the STN type liquid crystal display device. In the VA type liquid crystal display device, rubbing treatment may not be performed in many cases, but may be performed.

Subsequently, an adhesive is applied onto one of the substrates, and the liquid crystal is injected in a vacuum. In the case of the dropwise injection method, the liquid crystal is dropped onto the substrate before the substrates are attached to each other, and then the substrates are attached to each other with the other substrate. The adhesive used for adhering is cured by heat or ultraviolet rays to produce the liquid crystal display element of the present invention.

A polarizing plate (polarizing film), a wave plate, a light-scattering film, a driving circuit, and the like may be mounted on the liquid crystal display element of the present invention.

[Example]

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. On the other hand, the names of tetracarboxylic dianhydrides, diamines and solvents which can be used in the examples are indicated by the following abbreviations.

[Tetracarboxylic acid dianhydride]

Pyromellitic acid dianhydride {(1)}: PMDA

1,2,3,4-Cyclobutane tetracarboxylic acid dianhydride {(19)}: CBDA

Butanetetracarboxylic dianhydride {(23)}: BDA

2,3,5-tricarboxycyclopentylacetic acid dianhydride {(49)}: TCMP

[Diamine]

4,4'-diaminodiphenylmethane {Formula (V-1)}: DDM

4,4'-diaminodiphenylethane {formula (V-7)}: DET

Bis [benzeneamine] {Formula (VII-2)}: BABZP3 (4-phenylphenylmethylene)

2- (phenylmethyl) -1,4-diaminobenzene (formula (IV-16)): PhPDA

Phenyl] methyl] -1,3-diaminobenzene (formula (VIII-5) / R ²³ = (1-benzyloxycarbonylamino) C ₅ H ₁₁ }: 5ChCh

(XI-1) / R ²⁹ = C ₅ H ₁₁ }: 5HBA (4-aminophenoxy) phenyl) -4-n-pentylcyclohexane

(XI-2) / R ²⁹ = C ₇ H ₁₅ }: 7HBZ (4-aminophenyl) methyl) phenyl) -4-n-heptylcyclohexane

(XI-6) / R ³⁰ = C ₇ H ₁₅ }: 7H 2 HBA (formula (XI-6)) was obtained in the same manner as in Example 1, except that 1,1-bis [

[Compound of thioran]

N, N, N ', N'-tetrakisthienylmethyl-4,4'-diaminodiphenylmethane: TMAP

[Oxazoline compound]

Poly (styrene-co-2-isopropenyl-oxazoline) (Epochros RPS-1005 manufactured by Nippon Printing Co., Ltd.): PSO

1,3-bis (4,5-dihydro-2-oxazolyl) benzene: BHO

[Oxirane compound]

Phenol-dicyclopentadiene (DCPD) resin-type epoxy resin (Epikron HP-7200HH manufactured by Dainippon Ink and Chemicals, Inc.): EPO

2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane: EES

[menstruum]

N-methyl-2-pyrrolidone: NMP

Butyl cellosolve (ethylene glycol monobutyl ether): BC

? -butyrolactone: GBL

<1. Synthesis of polyamic acid>

[Synthesis of polyamic acid]

Synthetic example  One

1.676 g of 5ChCh, 1.792 g of PhPDA and 58 g of dehydrated NMP were put into a 100 mL four-necked flask equipped with a thermometer, a stirrer, a feed inlet and a nitrogen gas inlet, and dissolved by stirring in a dry nitrogen stream. Subsequently, 2.532 g of CBDA was added, and the reaction was allowed to proceed at room temperature for 30 hours. When the reaction temperature rose during the reaction, the reaction was carried out while suppressing the reaction temperature to about 70 캜 or lower. 36 g of BC was added to the obtained solution to synthesize a polyamic acid solution (PA1) having a concentration of 6% by weight. The weight average molecular weight of the obtained PA1 was 37,000.

Here, the weight average molecular weight of the polyamic acid was determined by diluting the obtained polyamic acid with a diluting solution of (phosphoric acid / DMF = 0.6 / 100: weight ratio) so that the concentration of polyamic acid was about 1% by weight, Product) was used, and the diluted solution was measured as a developing agent by the GPC method and was found by polystyrene conversion. On the other hand, the column was measured under the conditions of a column temperature of 50 캜 and a flow rate of 0.6 mL / min using GF-7HQ (manufactured by Showa Denko KK).

Synthetic example  2, 3

As shown in Table 1, a polyamic acid solution (PA2, PA3) was synthesized in accordance with Synthesis Example 1, except that the composition of tetracarboxylic dianhydride, diamine and solvent was changed. The results, including Synthesis Example 1, are summarized in Table 1.

Synthetic example  4

2.919 g of DDM, 54 g of dehydrated NMP, and 15 g of dehydrated GBL were placed in a 100 mL four-necked flask equipped with a thermometer, a stirrer, a feed inlet and a nitrogen gas inlet, and dissolved by stirring in a dry nitrogen stream. Subsequently, 1.155 g of CBDA and 1.927 g of PMDA were added and reacted for 30 hours at room temperature. When the reaction temperature rises during the reaction, the reaction temperature is lowered to about 70 캜 or lower and the reaction is carried out. To the obtained solution, 25 g of BC was added to prepare a polyamic acid solution (PA4) having a concentration of 6% by weight. The weight average molecular weight of the obtained PA4 was 45,000.

Synthetic example  5 to 10

As shown in Table 1, polyamic acid solutions (PA5 to PA10) were synthesized in accordance with Synthesis Example 4, except that the composition of tetracarboxylic dianhydride, diamine and solvent was changed. Synthesis Example 4 was included, and the results are summarized in Table 1.

[Table 1]

<2. Production of liquid crystal display device >

[Example 1]

A polyamic acid solution (PA1) having a concentration of 6% by weight synthesized in Synthesis Example 1 and a polyamic acid solution (PA2) having a concentration of 6% by weight synthesized in Synthesis Example 2 were mixed at a weight ratio of 1/9. To the resulting mixture, 5 wt% of TMAP as a thiocyanate compound was added per weight of the polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 2]

A polyamic acid solution (PA1) having a concentration of 6% by weight synthesized in Synthesis Example 1 and a polyamic acid solution (PA3) having a concentration of 6% by weight synthesized in Synthesis Example 3 were mixed at a weight ratio of 1/9. PSO, which is an oxazoline compound, was added to the resulting mixture in an amount of 10% by weight based on the weight of the polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Comparative Example 1]

A polyamic acid solution (PA1) having a concentration of 6% by weight synthesized in Synthesis Example 1 and a polyamic acid solution (PA2) having a concentration of 6% by weight synthesized in Synthesis Example 2 were mixed at a weight ratio of 1/9. A mixed solvent of NMP / BC = 1/1 (weight ratio) was added to the obtained mixture, and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Comparative Example 2]

A polyamic acid solution (PA1) having a concentration of 6% by weight synthesized in Synthesis Example 1 and a polyamic acid solution (PA3) having a concentration of 6% by weight synthesized in Synthesis Example 3 were mixed at a weight ratio of 1/9. A mixed solvent (polyamic acid) of NMP / BC = 1/1 (weight ratio) was added to the obtained mixture, and the mixture was diluted to 4 wt% with respect to the whole to obtain a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

Method for producing liquid crystal display element [Examples 1 and 2 and Comparative Examples 1 and 2]

The liquid crystal aligning agent was coated on a glass substrate with two ITO electrodes by a spinner to form a film having a film thickness of 70 nm. After the coating, the coating film was heated and dried at 80 DEG C for about 5 minutes, and then heat-treated at 220 DEG C for 40 minutes. Then, the obtained polyimide film was rubbed to form a liquid crystal alignment film. The rubbing treatment was carried out in the same manner as in Example 1 except that the obtained polyimide film was subjected to rubbing treatment using a rubbing treatment apparatus RM02-9 type manufactured by Iinuma Kogyo Co., Ltd. and a rabbit cloth (hair length: 1.9 mm: Rayon YA-18R manufactured by Yoshikawa Kako Co., An indentation of 0.40 mm, a stage moving speed of 60 mm / sec, and a roller rotation speed of 1,000 rpm.

The liquid crystal alignment film formed on the glass substrate was ultrasonically cleaned in ultrapure water for 5 minutes and then dried in an oven at 120 ° C for 30 minutes.

A pair of glass substrates on which a liquid crystal alignment film was formed was arranged so as to face the one glass substrate with a gap material of 4 mu m dispersed thereon so that the surface on which the liquid crystal alignment film was formed faced inward and the rubbing direction was inversely parallel, The periphery of the alignment film was sealed with an epoxy curing agent to prepare an anti-parallel cell having a gap of 4 탆. The liquid crystal composition I shown below was injected into the gap of the cell and the injection port for liquid crystal composition was sealed with a photo-curing agent. Subsequently, the substrate was heat-treated at 110 DEG C for 30 minutes to produce a liquid crystal display element.

Liquid crystal composition I

[Example 3]

A polyamic acid solution (PA4) having a concentration of 6 wt% synthesized in Synthesis Example 4 and a polyamic acid solution (PA5) having a concentration of 6 wt% synthesized in Synthesis Example 5 were mixed at a weight ratio of 2/8. To the resulting mixture, 10 wt% of BHO, which is an oxazoline compound, was added per weight of polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 4]

A polyamic acid solution (PA4) having a concentration of 6% by weight synthesized in Synthesis Example 4 and a polyamic acid solution (PA6) having a concentration of 6% by weight synthesized in Synthesis Example 6 were mixed at a weight ratio of 2/8. To the resulting mixture, 10 wt% of BHO, which is an oxazoline compound, was added per weight of polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 5]

A polyamic acid solution (PA4) having a concentration of 6% by weight synthesized in Synthesis Example 4 and a polyamic acid solution (PA7) having a concentration of 6% by weight synthesized in Synthesis Example 7 were mixed at a weight ratio of 2/8. To the resulting mixture, 10 wt% of BHO, which is an oxazoline compound, was added per weight of polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 6]

A polyamic acid solution (PA4) having a concentration of 6% by weight synthesized in Synthesis Example 4 and a polyamic acid solution (PA7) having a concentration of 6% by weight synthesized in Synthesis Example 7 were mixed at a weight ratio of 1/9. To the resulting mixture, 20 weight% of BHO, which is an oxazoline compound, was added per weight of polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 7]

A polyamic acid solution (PA4) having a concentration of 6% by weight synthesized in Synthesis Example 4 and a polyamic acid solution (PA7) having a concentration of 6% by weight synthesized in Synthesis Example 7 were mixed at a weight ratio of 2/8. PSO, which is an oxazoline compound, was added to the resulting mixture in an amount of 10% by weight based on the weight of the polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 8]

To the polyamic acid solution (PA8) having a concentration of 6% by weight synthesized in Synthesis Example 8, BHO as an oxazoline compound was added in an amount of 10% by weight based on the weight of the polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 9]

To the polyamic acid solution (PA9) having a concentration of 6% by weight synthesized in Synthesis Example 9, 20% by weight of BHO, which is an oxazoline compound, was added per weight of the polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 10]

To the polyamic acid solution (PA10) having a concentration of 6% by weight synthesized in Synthesis Example 10, BHO, which is an oxazoline compound, was added in an amount of 10% by weight based on the weight of the polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 11]

To the polyamic acid solution (PA9) having a concentration of 6% by weight synthesized in Synthesis Example 9, PSO as an oxazoline compound was added in an amount of 10% by weight based on the weight of the polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 12]

A polyamic acid solution (PA4) having a concentration of 6 wt% synthesized in Synthesis Example 4 and a polyamic acid solution (PA5) having a concentration of 6 wt% synthesized in Synthesis Example 5 were mixed at a weight ratio of 2/8. To the resulting mixture, 10 wt% of BHO, which is an oxazoline compound, was added per weight of polymer, and 10 wt% of EPO as an oxirane compound was added per weight of polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Example 13]

A polyamic acid solution (PA4) having a concentration of 6 wt% synthesized in Synthesis Example 4 and a polyamic acid solution (PA5) having a concentration of 6 wt% synthesized in Synthesis Example 5 were mixed at a weight ratio of 2/8. To the obtained mixture, 10 weight% of BHO, which is an oxazoline compound, was added per weight of polymer, and 10 weight% of EIL as an oxirane compound was added per weight of polymer. Subsequently, a mixed solvent of NMP / BC = 1/1 (weight ratio) was added and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Comparative Example 3]

A polyamic acid solution (PA4) having a concentration of 6 wt% synthesized in Synthesis Example 4 and a polyamic acid solution (PA5) having a concentration of 6 wt% synthesized in Synthesis Example 5 were mixed at a weight ratio of 2/8. A mixed solvent of NMP / BC = 1/1 (weight ratio) was added to the obtained mixture, and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Comparative Example 4]

A polyamic acid solution (PA4) having a concentration of 6% by weight synthesized in Synthesis Example 4 and a polyamic acid solution (PA7) having a concentration of 6% by weight synthesized in Synthesis Example 7 were mixed at a weight ratio of 2/8. A mixed solvent of NMP / BC = 1/1 (weight ratio) was added to the obtained mixture, and the polyamic acid was diluted to 4% by weight with respect to the total weight to prepare a liquid crystal aligning agent. Using the obtained liquid crystal aligning agent, a liquid crystal display element was produced as in the following.

[Comparative Example 5]

A mixed solvent of NMP / BC = 1/1 (weight ratio) was added to a polyamic acid solution (PA9) having a concentration of 6 wt% synthesized in Synthesis Example 9 to dilute the polyamic acid to 4 wt% Respectively. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

[Comparative Example 6]

A mixed solvent of NMP / BC = 1/1 (weight ratio) was added to the polyamic acid solution (PA10) having a concentration of 6% by weight synthesized in Synthesis Example 10 to dilute the polyamic acid to 4% Respectively. Using the obtained liquid crystal aligning agent, a liquid crystal display device was produced as follows.

Production method of liquid crystal display element [Examples 3 to 13 and Comparative Examples 3 to 6]

The liquid crystal aligning agent was coated on a glass substrate with two ITO electrodes by a spinner to form a film with a film thickness of 70 nm. After the coating, the coating film was heated and dried at 80 DEG C for about 5 minutes, and then heat-treated at 220 DEG C for 20 minutes. Then, the resulting polyimide film was rubbed to form a liquid crystal alignment film. The rubbing treatment was carried out in the same manner as in Example 1 except that the obtained polyimide film was subjected to rubbing treatment using a rubbing treatment apparatus RM02-9, a product of Iinuma Kogyo Co., Ltd., with a thickness of 0.40 mm on a rubbing cloth (length of the hair of 1.9 mm: Rayon YA-18R manufactured by Yoshikawa Kikai Co., The moving speed was 60 mm / sec, and the roller rotation speed was 1,000 rpm.

The liquid crystal alignment film formed on the glass substrate was ultrasonically cleaned in ultrapure water for 5 minutes and then dried in an oven at 120 캜 for 30 minutes.

A pair of glass substrates on which a liquid crystal alignment film was formed were arranged so as to face each other so that the rubbing direction was opposite to the direction in which the liquid crystal alignment film was formed and the surface on which the liquid crystal alignment film was formed was disposed opposite to the periphery of the liquid crystal alignment film Was sealed with an epoxy curing agent to prepare an antiparallel cell having a gap of 7 mu m. The liquid crystal composition II shown below was injected into the gap in the cell, and the injection port for the liquid crystal composition was sealed with a photo-curing agent. Subsequently, the substrate was heat-treated at 110 DEG C for 30 minutes to produce a liquid crystal display element.

Liquid crystal composition II

<3. Evaluation of electric characteristics>

[Test Examples 1 to 19]

For the liquid crystal display devices manufactured in Examples 1 to 13 and Comparative Examples 1 to 6, the measurement of the voltage holding ratio and the measurement of the long-term reliability were carried out as follows.

1) Measurement of voltage holding ratio

The voltage retention ratio was measured using a liquid crystal physical property evaluation device Model 6254 manufactured by Toyo Technica. The measurement conditions were a gate width of 60 μs, a frequency of 0.3 Hz, a wavelength of ± 5 V, and a measurement temperature of 60 ° C. The larger the value, the better the electrical characteristics. The results are shown in Tables 2 and 3.

2-1) Measurement of long-term reliability [Test examples 1 to 4]

With respect to the liquid crystal display device manufactured, the voltage holding ratio with the lapse of time was determined and the holding characteristics were evaluated. As a test method of the holding property, the liquid crystal display device was left in an atmosphere at a temperature of 100 캜 for 100 hours, and the voltage holding ratio with time was measured during the course. As long as the decrease of the voltage holding ratio is small (for example, the rate of decrease of the voltage holding ratio is less than 1% at a standing time of 100 hours or more under the above conditions), the long term reliability is good. The results are shown in Table 2. The rate of decrease can be obtained by the following equation.

(%) = (Initial voltage holding ratio - voltage holding ratio at the end) / (initial voltage holding ratio) x 100

[Table 2]

2-2) Measurement of long-term reliability [Test examples 5 to 19]

With respect to the liquid crystal display device manufactured, the voltage holding ratio with the lapse of time was determined and the holding characteristics were evaluated. As for the test method of the holding characteristics, the liquid crystal display device was left in an atmosphere at a temperature of 60 캜 for 500 hours, and the outgoing voltage retention rate was measured over time during the course. As long as the decrease in the voltage holding ratio is small (for example, the rate of decrease in the voltage holding ratio is less than 2% at a setting time of 500 hours or more under the above conditions), the long term reliability is good. The results are shown in Table 3.

[Table 3]

As shown in Tables 2 and 3, in the case of a liquid crystal display device using a liquid crystal alignment film in which the above compounds were mixed, the deterioration of the storage characteristics was remarkably suppressed. It is considered that any action such as reaction of the thiocyanate compound and the oxazoline compound with respect to the polyamic acid is a result of the respective effects. Considering the reactivity and the like in the heterocyclic structure, the oxetane compound and the aziridine compound are also expected to have the same effects as those of the thiirane compound and the oxazoline compound.

In addition, when the oxirane compound is used in combination with the above compound in the liquid crystal aligning agent, deterioration of the storage characteristics of the obtained liquid crystal display element is more remarkably suppressed as compared with the case where the above compound is used alone.

As described above, when the liquid crystal aligning agent containing the polyamic acid and the compound in the present invention is a liquid crystal alignment film of a liquid crystal display element, the voltage retention ratio is high and the deterioration of the storage characteristics can be remarkably suppressed.

Claims (23)

One or two or more heterocyclic compounds each having one or two or more heterocyclic structures selected from the group consisting of oxadiene, oxetane, thiirane, aziridine, and oxazoline, and 1 or 2 selected from polyamic acid and derivatives thereof Wherein the liquid crystal aligning agent contains the heterocyclic compound in an amount of 0.1 to 50% by weight based on the polymer. The method according to claim 1, Wherein the heterocyclic compound is a compound having two or more heterocyclic structures. The method according to claim 1, Wherein the heterocyclic compound is a polymer having the heterocyclic structure in the side chain. The method of claim 3, A liquid crystal aligning agent characterized in that the polymer is a copolymer. The method according to claim 1, Wherein the polyamic acid is a reaction product obtained by reacting tetracarboxylic acid dianhydride as an acid component with diamine as an amine component. 6. The method of claim 5, Wherein the acid component comprises an A component and a B component, and an aromatic tetracarboxylic acid dianhydride is used as an A component of an acid, and the aromatic tetracarboxylic dianhydride is represented by the following structural formulas (1), (2), 7), and (14). &Lt; / RTI &gt;

The method according to claim 6, Wherein the aromatic tetracarboxylic acid dianhydride is the compound of the structural formula (1). The method according to claim 6, Wherein at least one of aliphatic tetracarboxylic acid dianhydride and alicyclic tetracarboxylic acid dianhydride is used as the B component of the acid. 9. The method of claim 8, The aliphatic tetracarboxylic dianhydride and the alicyclic tetracarboxylic dianhydride are represented by the following structural formulas (19), (23), (25), (35) to (37), (39), (44), and Wherein the liquid crystal aligning agent is a compound selected from the group consisting of

10. The method of claim 9, Wherein the alicyclic tetracarboxylic dianhydride is a compound selected from the group consisting of the structural formulas (19), (23) and (49). 6. The method of claim 5, Wherein the amine component comprises a diamine represented by a general formula selected from the group consisting of the following general formulas (I) to (VII) as an A component of the amine, wherein the amine component comprises an A component and a B component: .

(I), A ¹ represents - (CH ₂ ) _m -, wherein m represents an integer of 1 to 12. Further, in the general formulas (III), (V) and (VII) in, a ¹ is independently a single bond, -O-, -S-, -SS-, -SO 2 -, -CO-, -CONH-, -NHCO-, -C (CH 3) 2 -, - _{C (CF 3) 2 -,} - (CH 2) m -, -O- (CH 2) m -O-, or -S- (CH _{2) m} represents a -S-, where m is 1 to 12 of an integer addition, in the general formula (VI), a ² are independently a single bond, -O-, -S-, -CO-, -C (CH 3) 2 -., -C (CF 3) ₂ - or an alkylene of 1 to 6 carbon atoms. The hydrogen bonded to the cyclohexane ring or the benzene ring in the formulas (II) to (VII) is independently -F, -CH ₃ , -OH, It is optionally substituted with _{-COOH, -SO 3 H, -PO 3} H 2, benzyl or 4-hydroxybenzyl) 12. The method of claim 11, The diamines of the component A are represented by the following formulas (IV-1), (IV-2), (IV-15), (IV- Is a compound selected from the group consisting of compounds (VII-1) and (VII-2).

12. The method of claim 11, A diamine represented by a general formula selected from the group consisting of the following general formulas (VIII) and (IX) to (XII) is used as the B component of the amine.

(In the formula (VIII), R ¹ represents a single bond, -O-, -CO-, -COO-, -OCO-, -CONH-, -CH ₂ O-, -CF ₂ O- or (CH ₂ ) _e -, e is an integer of 1 to 6, R ² is a group having a steroid skeleton, a group represented by the general formula (XIII), alkyl having 1 to 30 carbon atoms, or phenyl, 6, the optional -CH ₂ - may be independently replaced with -O- (but not contiguous), -CH = CH- or -C≡C-, and the hydrogen of the phenyl is independently Which may be substituted by fluorine, methyl, methoxy, fluoromethoxy, difluoromethoxy or trifluoromethoxy, In formula (IX), R ³ is independently hydrogen or methyl; R ⁴ is hydrogen or alkyl having 1 to 30 carbon atoms; R ⁵ is independently a single bond, -CO- or -CH ₂ - and: In formula (X), R ³ is independently hydrogen or methyl; R ⁴ is hydrogen or alkyl having 1 to 30 carbon atoms; R ⁵ is independently a single bond, -CO- or -CH ₂ -; And R ⁶ and R ⁷ are independently hydrogen, alkyl of 1 to 30 carbon atoms, or phenyl; In formula (XI), R ⁸ is hydrogen or alkyl having 1 to 30 carbon atoms, and any -CH ₂ - of the alkyl is independently -O- (but not continuous), -CH = CH- Or -C? C-; R ⁹ is independently -O- or alkylene having 1 to 6 carbon atoms; Ring A is 1,4-phenylene or 1,4-cyclohexylene; a is 0 or 1; b is 0, 1 or 2; And c is independently 0 or 1, In formula (XII), R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms; R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms, or alkyl fluoride having 1 to 30 carbon atoms; R ¹² is independently -O- or alkylene having 1 to 6 carbon atoms; And d is independently 0 or 1)

(Wherein R ¹³ , R ¹⁴ and R ¹⁵ are independently a single bond, -O-, -COO-, -OCO-, -CONH-, alkylene of 1 to 4 carbon atoms, alkylene of 1 to 3 carbon atoms R ¹⁶ and R ¹⁷ are independently hydrogen, fluorine or methyl, and R ¹⁸ is hydrogen, fluorine, chlorine, bromine or iodine, or an alkyleneoxy of 1 to 3 carbon atoms , Cyano, alkyl of 1 to 30 carbon atoms, alkoxy of 1 to 30 carbon atoms, alkoxyalkyl of 2 to 30 carbon atoms, fluoromethyl, difluoromethyl, trifluoromethyl, fluoromethoxy, difluoromethoxy or tri And any of -CH ₂ - in these alkyl, alkoxy and alkoxyalkyl may be substituted by a group represented by difluoromethylene or a group represented by formula (XIV); ring B and ring C are independently 1,4-phenylene or 1,4-cyclohexylene, f, g and h are independently an integer of 0 to 4; i, j and k are independently An integer from 0 to 3, their sum is 1 or more and; l and m is independently 1 or 2)

(Wherein, in the general formula (XIV), R ¹⁹ , R ²⁰ , R ²¹ and R ²² are independently alkyl having 1 to 10 carbon atoms or phenyl, and n is an integer of 1 to 100) 14. The method of claim 13, The diamine of the component B is at least one selected from the group consisting of the following formulas (VIII-2), (VIII-4), (VIII-5), (VIII- Wherein the diamine is a diamine represented by a general formula selected from the group consisting of:

(Wherein R ²³ is independently an alkyl having 3 to 30 carbon atoms or an alkoxy having 3 to 30 carbon atoms, R ²⁹ is hydrogen or an alkyl group having 1 to 30 carbon atoms, R ³⁰ is hydrogen, 20 &lt; / RTI &gt; The method according to claim 1, A liquid crystal aligning agent characterized by containing two or more kinds of the above-mentioned polymers. The method according to claim 1, A liquid crystal aligning agent characterized by further comprising an oxirane compound. As a liquid crystal aligning agent containing a heterocyclic compound having one or more heterocyclic structures of thianyl and oxazoline and a polyamic acid or a derivative thereof, The heterocyclic compound is contained in an amount of 1 to 40% by weight based on the polyamic acid or the derivative thereof, Wherein the polyamic acid or its derivative is a reaction product obtained by reacting tetracarboxylic dianhydride as an acid component and a diamine as an amine component, Wherein the tetracarboxylic acid dianhydride is at least one compound selected from the group consisting of the following structural formulas (1), (2), (5) to (7) and (14) As a component, at least one of compounds selected from the group consisting of the following structural formulas (19), (23), (25), (35) to (37), (39), (44) One or both, The diamine is a compound represented by the following structural formulas (IV-1), (IV-2), (IV-15), (IV-16), (V- (VIII-2), (VIII-4), and (VIII-2) as the B component of the amine, and one or more of the compounds selected from the group consisting of Or one or more of the compounds represented by the general formula selected from the group consisting of (XI-1), (XI-5), (VIII-6) And a liquid crystal alignment agent.

(Wherein R ²³ is independently an alkyl having 3 to 30 carbon atoms or an alkoxy having 3 to 30 carbon atoms, R ²⁹ is hydrogen or an alkyl group having 1 to 30 carbon atoms, R ³⁰ is hydrogen, 20 &lt; / RTI &gt; 18. The method of claim 17, Wherein the tetracarboxylic dianhydride is a compound selected from the group consisting of the compounds represented by the structural formulas (19), (23) and (49) as the component (B) Or both, The diamine is one or two or more compounds selected from the group consisting of the structural formulas (IV-16), (V-1), (V-7) and (VII-2) And the B component of the amine, The heterocyclic compound may be at least one selected from the group consisting of N, N, N ', N', - tetrakisthienylmethyl-4,4'-diaminodiphenylethane, poly (styrene- And 1,3-bis (4,5-dihydro-2-oxazolyl) benzene. The liquid crystal aligning agent according to claim 1, wherein the liquid crystal aligning agent is at least one compound selected from the group consisting of 1,3- 19. The method of claim 18, Wherein the amine component B is represented by a general formula selected from the group consisting of the general formulas (VIII-2), (VIII-5), (XI-1), (XI-2) Wherein the liquid crystal aligning agent is one or two or more of the compounds. 18. The method of claim 17, A liquid crystal aligning agent characterized by further comprising an oxirane compound. 21. The method of claim 20, Wherein the oxirane compound is at least one of phenol-dicyclopentadiene resin type epoxy resin and 2- (3,4-epoxycyclohexyl) ethyl trimethoxy silane. A liquid crystal alignment film formed by firing a liquid crystal aligning agent according to any one of claims 1 to 21 in a film state. A liquid crystal alignment film formed on an opposing face of each of the pair of substrates; a liquid crystal alignment film formed on the opposing face of each of the pair of substrates; A liquid crystal display element having a liquid crystal layer formed between a pair of substrates, The liquid crystal display element according to claim 22, wherein the liquid crystal alignment film is the liquid crystal alignment film according to claim 22.