TWI504677B - Liquid crystal orientating agent, liquid crystal orientating film and liquid crystal display element - Google Patents

Description

Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

The present invention relates to a liquid crystal alignment agent which is suitable as a material for forming a liquid crystal alignment film, a liquid crystal alignment film formed of the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film.

Background technique

Since the liquid crystal display element has advantages such as low power consumption, ease of miniaturization, and flatness, it is used in a wide range of applications from a small liquid crystal display device such as a mobile phone to a large-screen liquid crystal display device such as a liquid crystal television.

The driving mode of the liquid crystal display device is known to have a twisted nematic type (TN type), a super twisted nematic type (STN type), an in-plane switching type (IPS type), depending on a change in the alignment state of the liquid crystal molecules. A liquid crystal display element of a liquid crystal cell such as a vertical alignment type (VA type). In any of the display modes, the alignment state of the liquid crystal molecules is controlled by the liquid crystal alignment film, so that the properties of the liquid crystal alignment film and the liquid crystal alignment agent which is a material of the liquid crystal alignment film affect the performance of the liquid crystal display element.

For the material of the liquid crystal alignment agent, for example, Patent Documents 1 to 6 disclose resin materials such as polyacrylic acid, polyamidiamine, polyamide, polyester, and the like, in particular, polyglycine or poly The liquid crystal alignment film formed of the liquid crystal alignment agent of the phthalimide is excellent in affinity, heat resistance, mechanical strength, and the like, and is used in a large amount in liquid crystal display elements.

However, in recent years, the use range of liquid crystal display elements has been expanded, and it is required that a liquid crystal display element in which display quality is not lowered even if it is continuously driven for a long period of time, a liquid crystal display element using current polylysine or polyimine as a material, When driving continuously for a long period of time, the liquid crystal alignment film may be deteriorated due to heat or light, resulting in deterioration of electrical properties, poor alignment of liquid crystal molecules, and the like. In order to solve this problem, a technique of using a large amount of a liquid crystal alignment agent containing a polyfunctional epoxy compound has been developed (refer to Japanese Patent No. 3799700, JP-A-2008-299318).

On the other hand, a substrate including defects such as pores and uneven coating of the coating film which are generated in the production process of the liquid crystal alignment film may be peeled off for reuse (hereinafter, also referred to as "rework"). In this rework, the liquid crystal alignment film is required to have releasability to the substrate. However, if a large amount of the liquid crystal alignment agent containing the above polyfunctional epoxy group is used, the crosslinking property of the epoxy group at the time of baking may lower the peeling property of the liquid crystal alignment film at the time of rework.

In view of the above, it has been desired to develop a liquid crystal alignment film which is capable of suppressing deterioration in display quality due to deterioration of electrical properties or the like even when continuously driven for a long period of time, and which is easily peeled off during rework.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 4-156622

[Patent Document 2] Japanese Patent Laid-Open Publication No. SHO 60-107020

[Patent Document 3] Japanese Patent Laid-Open No. 56-91277

[Patent Document 4] US Patent No. 5,928,733

[Patent Document 5] Japanese Laid-Open Patent Publication No. 62-165628

[Patent Document 6] Japanese Patent Laid-Open No. Hei 11-258605

[Patent Document 7] Japanese Patent No. 3799700

[Patent Document 8] Japanese Patent Laid-Open Publication No. 2008-299318

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a liquid crystal alignment film which is capable of suppressing deterioration in electrical properties due to deterioration of electrical properties, and which is easily peeled off during reworking, and is suitable for formation. A liquid crystal alignment agent of a material of the alignment film, and a liquid crystal display element having the liquid crystal alignment film.

The present invention proposed to solve the above problems is a liquid crystal alignment agent comprising:

[A] at least one polymer selected from the group consisting of polyproline and polyimine (hereinafter, also referred to as polymer [A]), and

[B] An oxime ring-containing epoxy compound represented by the following formula (I) (hereinafter also referred to as epoxy compound [B]).

In the formula (I), R ^A is a single bond or an alkanedi group having 1 to 4 carbon atoms. R ^B is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic group, a divalent heterocyclic group, or a group formed by combining them. n is an integer of 0 or 1.

By containing the specific polymer [A] and the epoxy compound [B], the liquid crystal alignment agent can form a liquid crystal alignment film which is resistant to deterioration in display quality due to deterioration in electrical properties and the like, and which is easily peeled off during rework.

The above formula (I) is preferably at least one selected from the group consisting of compounds represented by the following formula (I-1) and formula (I-2).

In the formula (I-1) and the formula (I-2), R ^{A has the} same meaning as defined in the above formula (I). R ^1, R ² and R ³ are each independently, may comprise as -O -, - COO -, - OCO- number of carbon atoms in a linear or branched alkyl group having 1 to 20. Further, R ¹ and R ² or R ¹ and R ² and R ³ are bonded to each other to form a ring structure in which a part or all of a hydrogen atom may be substituted. n is an integer of 0 or 1.

By selecting the compound of the above formula (I) as a specific compound, it is possible to form a liquid crystal alignment film which is suppressed from being deteriorated in display quality due to deterioration in electrical properties and the like, and which is easily peeled off during rework.

The polymer [A] is preferably at least one selected from the group consisting of polylysine and polyamidene formed by dehydration of the polyglycolic acid, wherein the polyamic acid uses tetracarboxylic dianhydride. To synthesize, the tetracarboxylic dianhydride comprises 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 3,5,6-tricarboxy-2-carboxymethyl group. Selected from the group consisting of alkane-2:3,5:6-dianhydride and 2,4,6,8-tetracarboxybicyclo[3.3.0]-octane-2:4,6:8-dianhydride At least one. By using the polymer [A] synthesized by using this specific compound as the tetracarboxylic dianhydride, the desired properties can be further exhibited.

R ^{A of the} above formula (I) is preferably methanediyl. Further, in the above formula (I-1) and formula (I-2), R ¹ and R ^{2 are} preferably bonded to each other to form a benzene ring in which a part or all of a hydrogen atom may be substituted. The epoxy compound [B] can further improve electrical properties and releasability at the time of rework by having the above specific structure.

The liquid crystal display element of the present invention has a liquid crystal alignment film formed of the liquid crystal alignment agent. The liquid crystal display element is suitable for use in various devices, such as a clock, a portable game machine, a word processor, a notebook computer, a navigation system, a portable video camera, a portable information terminal, a digital camera, a mobile phone, and various monitors. Use in display devices such as LCD TVs.

A polymer composition comprising: [A] at least one polymer selected from the group consisting of polyproline and polyimine, and [B] a yttrium represented by the following formula (I) An epoxy compound of an amine ring.

In the formula (I), R ^A is a single bond or an alkanediyl group having 1 to 4 carbon atoms. R ^B is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic group, a divalent heterocyclic group, or a group formed by combining them. n is an integer of 0 or 1.

The polymer composition is suitably used as a component of a liquid crystal alignment agent or the like for forming a liquid crystal alignment film. Further, the film formed of the polymer composition can also be used as an insulating film for electronic materials.

According to the present invention, it is possible to form a liquid crystal alignment film which is suppressed from being deteriorated in display quality due to deterioration in electrical properties and the like, and which is easily peeled off upon re-peeling. The liquid crystal display element is suitable for use in various devices, such as a clock, a portable game machine, a word processor, a notebook computer, a navigation system, a camcorder, a portable information terminal, a digital camera, a mobile phone, various monitors, Used in display devices such as LCD TVs.

Hereinafter, embodiments of the invention will be described in detail.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention contains the polymer [A] and the epoxy compound [B]. By containing the specific polymer [A] and the epoxy compound [B], the liquid crystal alignment agent can form a liquid crystal alignment film which suppresses deterioration in display quality due to deterioration of electrical properties and the like, and is easily peeled off upon re-peeling. Further, the liquid crystal alignment agent may contain an optional component as long as the effects of the present invention are not impaired. Hereinafter, the polymer [A], the epoxy compound [B], and optional components will be described in detail.

<Polymer [A]>

The polymer [A] contained in the liquid crystal alignment agent of the present invention is at least one polymer selected from the group consisting of polyproline and polyimine. Hereinafter, polyamine and polyimine are described in detail.

[polyglycolic acid]

Polylysine can be obtained by reacting a tetracarboxylic dianhydride with a diamine compound.

Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. In addition to the above, the tetracarboxylic dianhydride described in Japanese Patent Application No. 2009-157556 can also be used. These tetracarboxylic dianhydrides can be used individually or in combination of 2 or more types.

Examples of the aliphatic tetracarboxylic dianhydride include butane tetracarboxylic dianhydride and the like.

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, and 1,3. , 3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1 ,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1 , 3-dione, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2, 5-dihydrotetrahydro-3-furanyl-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethyl group Alkane-2:3,5:6-dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 4,9-dioxa Tricyclic [5.3.1.0 ^2,6 ] eleven carbon-3,5,8,10-tetraone and the like.

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and the like.

Among these tetracarboxylic dianhydrides, preferred are alicyclic tetracarboxylic dianhydrides and aromatic tetracarboxylic dianhydrides, more preferably 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,5. 6-tricarboxy-2-carboxymethyl group Alkane-2:3,5:6-dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 1,3,3a,4 ,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, pyromellitic dianhydride, and particularly preferred is 2,3,5-tricarboxycyclopentyl acetic acid dianhydride. By using the polymer [A] synthesized from this specific compound as the tetracarboxylic dianhydride, the desired properties can be further exhibited.

The amount of the tetracarboxylic dianhydride to be used is preferably 10 mol% or more, more preferably 20 mol% or more, based on the total amount of the tetracarboxylic dianhydride, and particularly preferably only 2,3,5-tricarboxyl groups are used. Cyclopentyl acetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1] And 2- or more selected from the group consisting of furan-1,3-dione and 1,2,3,4-cyclotetracarboxylic dianhydride.

The diamine compound may, for example, be an aliphatic diamine, an alicyclic diamine, a diaminoorganomethoxy alkane or an aromatic diamine. In addition to the above, the diamine compound described in Japanese Patent Application No. 2009-157556 can also be used. These diamine compounds can be used individually or in combination of 2 or more types.

The aliphatic diamine may, for example, be 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine or hexamethylenediamine.

Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and 1,3-bis(aminomethyl). Cyclohexane and the like.

Examples of the diamine organooxosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldioxane and the like.

Examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, and 1,5-diamine. Naphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,7 -diaminoguanidine, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-amine Phenyl, fluorene, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4 '-(p-phenylene isopropylidene) bis(aniline), 4,4'-(m-phenylene isopropylidene)bis(aniline), 1,4-bis(4-aminophenoxy) Benzene, 3,4-diaminopyridine, 4,4'-bis(4-aminophenoxy)biphenyl, 3,6-diaminocarbazole, 2,6-diaminopyridine, 2 , 4-diaminopyrimidine, 3,6-diaminoacridine, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, 1, 4-bis(4-aminophenyl)perazine , 3,5-diaminobenzoic acid, N-phenyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, N,N'-double (4-Aminophenyl)-N,N'-dimethylbenzidine, dodecyloxy-2,4-diaminobenzene, tetradecyloxy-2,4-diaminobenzene, Pentadecyloxy-2,4-diaminobenzene, cetyloxy-2,4-diaminobenzene, octadecyloxy-2,4-diaminobenzene, dodecyloxy -2,5-diaminobenzene, tetradecyloxy-2,5-diaminobenzene, pentadecyloxy 2,5-diaminobenzene, hexadecyloxy-2,5-di Aminobenzene, octadecyloxy-2,5-diaminobenzene, cholestyloxy-3,5-diaminobenzene, cholestyloxy-3,5-diaminobenzene, gall Nonyloxy-2,4-diaminobenzene, cholesteneoxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diamine Cholestyrenyl benzoate, lanosteryl 3,5-diaminobenzoic acid, 3,6-bis(4-aminobenzylideneoxy)cholestane, 3,6-bis ( 4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzylideneoxy)cyclohexyl-3,5-diaminobenzoate, 4-(4'- Trifluoromethyl benzhydryloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-(( Aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)benzene) 4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline, 4-aminobenzylamine, 3-aminobenzylamine And a diamine compound represented by the following formula (1).

In the formula (1), X is an alkanediyl group having 1 to 3 carbon atoms, -O-, -COO- or -OCO-. a is 0 or 1. b is an integer from 0 to 2. c is an integer from 1 to 20.

In the above formula (1), specific examples of the C _c H _2c+1 group include, for example, a linear or branched methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. , heptyl, octyl, decyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nineteen Alkyl, eicosyl, and the like.

The diamine compound represented by the above formula (1) may, for example, be a compound represented by the following formulas (1-1) to (1-5).

In the above formula (1), a and b are preferably not 0 at the same time.

Among these diamine compounds, preferred are aromatic diamines, diamine organodecanes, more preferably p-phenylenediamine, 4,4'-diaminodiphenylmethane, 2,2'-dimethyl Base-4,4'-diaminobiphenyl, 3,6-bis(4-aminobenzylideneoxy)cholestane, cholesteryl 3,5-diaminobenzoate, cholesteric Alkoxy-2,4-diaminobenzene, 1,3-bis(3-aminopropyl)-tetramethyldioxane.

[Synthesis of polyglycine]

In terms of the ratio of use of the tetracarboxylic dianhydride and the diamine compound used in the synthesis reaction of polyproline, the acid anhydride group of the tetracarboxylic dianhydride is preferably based on the amine group contained in one equivalent of the diamine compound. 0.2 equivalents to 2 equivalents, more preferably 0.3 equivalents to 1.2 equivalents.

The synthesis reaction of polylysine is preferably carried out in an organic solvent. The reaction temperature is preferably -20 ° C to 150 ° C, more preferably 0 ° C to 100 ° C. In terms of reaction time, it is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

The organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid, and examples thereof include an aprotic polar solvent, a phenol and a derivative thereof, an alcohol, an ether, a halogenated hydrocarbon, and a hydrocarbon. Wait. These organic solvents may be used alone or in combination of two or more.

Examples of the aprotic polar solvent include guanamines, ketones, esters, and other aprotic polar solvents.

Examples of the guanamines include N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide, and N,N-dimethylacetamide.

Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of the esters include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, and diethyl oxalate. , diethyl malonate, γ-butyrolactone, isoamyl propionate, isoamyl isobutyrate, and the like.

Examples of the other aprotic polar solvent include dimethyl hydrazine, tetramethyl urea, hexamethylphosphonium triamide, and the like.

Examples of the phenol derivative include m-cresol, xylenol, halogenated phenol, and the like.

Examples of the alcohol include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, and diethyl ether. Glycol monomethyl ether, diethylene glycol monoethyl ether, and the like.

Examples of the ethers include diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, and ethylene glycol diisopropyl ether. Ethylene glycol di-n-butyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, Diethylene glycol monoethyl ether acetate, tetrahydrofuran, diisoamyl ether, and the like.

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

Examples of the hydrocarbons include hexane, heptane, octane, benzene, toluene, xylene, and the like.

Among these organic solvents, an aprotic polar solvent is preferred, and NMP and γ-butyrolactone are more preferred.

The amount (a) of the total amount (b) of the tetracarboxylic dianhydride and the diamine compound to the amount of the organic solvent (a) is preferably 0.1% by weight based on the amount (a) of the organic solvent. ~50% by weight.

The polyaminic acid solution obtained after the reaction can be directly used for preparing a liquid crystal alignment agent, or can be used for preparing a liquid crystal alignment agent after separating the polyamic acid contained in the reaction solution, or after separating the separated polyamic acid. For the preparation of liquid crystal alignment agents. For the separation method of the poly-proline, for example, a method in which a reaction solution is injected into a large amount of a poor solvent and the precipitate obtained by drying under reduced pressure is used, and a method of distilling off the reaction solution by an evaporator under reduced pressure is used. Examples of the method for purifying polylysine include a method in which the separated polylysine is dissolved again in an organic solvent and precipitated in a poor solvent; and the organic solvent is distilled off one or more times by evaporation under reduced pressure. A method of a step such as a solvent.

In the synthesis of polyamic acid, a terminally modified polymer can be synthesized together with a tetracarboxylic dianhydride and a diamine compound using a suitable molecular weight modifier. By forming the terminal-modified polymer, the coating property (printability) of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention.

The molecular weight modifier may, for example, be an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like.

The acid monoanhydride may, for example, be maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, or hexa Alkyl succinic anhydride and the like.

The monoamine compound may, for example, be aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine or n-octylamine.

The monoisocyanate compound may, for example, be phenyl isocyanate or naphthyl isocyanate.

The ratio of use of the molecular weight modifier is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less based on 100 parts by mass of the tetracarboxylic dianhydride and the diamine.

[polyimine]

The polyimine can be produced by subjecting the proline structure of the above polyamic acid to dehydration by ring closure.

Polyimine may be a complete hydrazine imide of a glycine structure having a proline structure as a precursor of polyproline, or may be a part of a proline structure, a dehydration ring closure, a proline structure and a hydrazine structure. Part of the quinone imine compound coexisting with the imine ring structure. Here, a part of the quinone ring may be an isoindole ring.

The ruthenium imidation ratio of the polyimine is preferably 30% or more, more preferably 40% to 99%. The oxime imidization ratio is a ratio indicating the amount of the quinone ring structure in the percentage of the amount of the guanine structure of the polyimine and the total amount of the quinone ring structure. Further, the ruthenium iodide ratio is a solution obtained by charging a solution of polyimine in pure water, and recovering the obtained precipitate, and drying it under reduced pressure at room temperature, and then dissolving it in dimethyl hydrazine. tetramethyl Silane as a standard material, was measured ¹ H-NMR spectrum of ¹ H-NMR obtained from room temperature, as shown by equation (2) by the following equation.

醯 imidization rate (%) = {1 - (A ¹ / A ² ) × α} × 100 (2)

In the formula (2), A ¹ is a peak area (10 ppm) of protons derived from the NH group. A ² is the peak area from other protons. α is the ratio of the number of other protons to the proton of the NH group in a poly-proline.

As for the synthesis method of the polyimine, for example, (i) a method of heating the poly-proline, (ii) dissolving the poly-proline in an organic solvent, adding a dehydrating agent and a dehydration ring in the solution The catalyst is subjected to a dehydration ring-closure reaction of polyglycine, such as a method of heating (hereinafter also referred to as "method (ii)), etc. Among these methods, the method (ii) is preferred.

The dehydrating agent in the method (ii) may, for example, be an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride.

The amount of the dehydrating agent to be used is appropriately selected depending on the desired ruthenium iodide ratio, and is preferably 0.01 mol to 20 mol with respect to the proline structure of 1 mol of polyamic acid.

The dehydration ring-closing catalyst in the method (ii) may, for example, be a third amine such as pyridine, trimethylpyridine, lutidine or triethylamine.

The amount of the dehydration ring-closure catalyst is preferably 0.01 mol to 10 mol based on 1 mol of the dehydrating agent contained.

The organic solvent used in the method (ii) is exemplified by the same organic solvent as the following organic solvent, and the organic solvent is exemplified as a solvent used as a synthetic polyamine.

The reaction temperature in the method (ii) is preferably from 0 ° C to 180 ° C, more preferably from 10 ° C to 150 ° C. In terms of reaction time, it is preferably from 1.0 to 120 hours, more preferably from 2.0 to 30 hours. By setting the reaction conditions to the above range, the dehydration ring-closure reaction proceeds sufficiently, and the molecular weight of the obtained polyimine can be made appropriate.

In the method (ii), a reaction solution containing polyienimine can be obtained. The reaction solution can be directly used for preparing a liquid crystal alignment agent, or can be used for preparing a liquid crystal alignment agent after removing a dehydrating agent and a dehydration ring-closing catalyst from the reaction solution; and can also be used for preparing a liquid crystal alignment agent after separating the polyimine; or After the isolated polyimine is refined, it is used to prepare a liquid crystal alignment agent. The method of removing the dehydrating agent and the dehydration ring-closure catalyst from the reaction solution can be carried out according to a known method, and examples thereof include the same methods as the separation method and the purification method of polyglycine.

The solution viscosity in the solution in which the concentration of the polymer [A] obtained above is 10% by mass is preferably 20 mPa ‧ to 800 mPa ‧ , more preferably 30 mPa ‧ to 500 mPa ‧ s. The solution viscosity (mPa‧s) of the polymer is a value measured at 25 ° C using a polymer solution having a concentration of 10% by mass prepared using γ-butyrolactone or NMP using an E-type rotational viscometer.

<epoxy compound [B]>

The epoxy compound [B] contained in the liquid crystal alignment agent of the present invention is an oximeimine ring-containing epoxy compound represented by the above formula (I).

In the above formula (I), R ^A is a single bond or an alkanediyl group having 1 to 4 carbon atoms. R ^B is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic group, a divalent heterocyclic group, or a group formed by combining them. n is an integer of 0 or 1.

Examples of the alkanediyl group having 1 to 4 carbon atoms include a methanediyl group, an ethylenediyl group, a propylenediyl group, and a butyldiyl group. Among them, a single bond or a methane diyl group is preferred.

The above formula (I) is preferably at least one selected from the group consisting of the compounds represented by the above formula (I-1) and formula (I-2). By selecting the compound of the above formula (I) as a specific compound, it is possible to form a liquid crystal alignment film which suppresses deterioration in display quality due to deterioration of electrical properties and the like, and which is easily peeled off during rework.

In the above formula (I-1) and formula (I-2), R ^{A has the} same meaning as defined in the above formula (I). R ¹ , R ² and R ³ are each independently a straight or branched alkyl group having 1 to 20 carbon atoms which may contain -O-, -COO- or -OCO-. Further, R ¹ and R ^2, or R ¹ and R ² and R ³ can be interconnected to form a part or all of the hydrogen atoms substituted with a ring structure. n is an integer of 0 or 1.

Examples of the linear or branched alkyl group having 1 to 20 carbon atoms include, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. Indenyl, fluorenyl, lauryl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, di Decylene and the like. Among them, a methyl group, an ethyl group, and a propyl group are preferred.

Further, R ¹ , R ² and R ³ in the above formulae (I-1) and (I-2) may form R ¹ and R ² or R ¹ and R ² and R ^{3 may} be bonded to each other to form a part of a hydrogen atom or All substituted ring structures. As the ring structure, an aromatic ring, an aliphatic ring, a heterocyclic ring, a condensed ring, and a ring formed by combining them may be mentioned. Among them, an aromatic ring is preferred, and a benzene ring or a naphthalene ring is more preferred.

The substituent which the ring structure which may be substituted may have, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, an alkyl group, a carboxyl group, a cycloalkyl group, an aryl group, an alkoxy group, a decyl group or a decyloxy group. , alkoxycarbonyl, cyanoalkyl, haloalkyl, and the like. Among them, a halogen atom, an alkyl group, a cyanoalkyl group or an alkoxy group is preferred, and a fluorine atom, a chlorine atom, a bromine atom, a methyl group, a cyanomethyl group or a methoxy group is more preferred.

n in the above formulae (I-1) and (I-2) is an integer of 0 or 1. n is preferably 0.

The above formula (I), R ^A is preferably a methane-diyl group. Further, in the above formula (I-1) and formula (I-2), R ¹ and R ^{2 are} preferably bonded to each other to form a benzene ring in which a part or the whole of a hydrogen atom may be substituted. The epoxy compound [B] can further improve electrical properties and releasability at the time of rework by having the above specific structure.

The compounds represented by the above formulas (I-1) and (I-2) include, for example, the following formulas (I-1-1) to (I-1-16) and (I-2-). 1) A compound represented by ~(I-2-14).

Among the above formulas (I-1-1) to (I-1-16) and (I-2-1) to (I-2-14), the special system (I-1-1), (I-1) -4), (I-1-15), (I-1-16), (I-2-6), the best system (I-1-4), (I-2-6).

Further, the epoxy group in the formula (I) may be substituted. The substituent may, for example, be a halogen atom, a hydroxyl group, a nitro group, a cyano group, an alkyl group, a carboxyl group, a cycloalkyl group, an aryl group, an alkoxy group, a decyl group, a decyloxy group, an alkoxycarbonyl group or a cyanogen group. Alkyl group, haloalkyl group, and the like.

The method for synthesizing the epoxy compound [B] is not particularly limited, and it can be carried out by a combination of a conventionally known method. In addition, products that are marketed can also be used.

The content ratio of the epoxy compound [B] is preferably 0.1 parts by mass to 50 parts by mass, more preferably 1 part by mass to 40 parts by mass, per 100 parts by mass of the polymer [A], and particularly preferably 3 parts by mass to 30 parts by mass. By setting the content ratio of the epoxy compound [B] to the above range, it is possible to provide a liquid crystal alignment film which can form a liquid crystal display element having less deterioration in electrical properties and high display quality even when driven for a long period of time, and can provide formation. A liquid crystal alignment agent having good peelability at the time of reworking of the film.

<arbitrary component>

Examples of the optional component include a functional decane compound and the like.

[functional decane compound]

The functional decane compound can be used for the purpose of improving the adhesion of the formed liquid crystal alignment film to the surface of the substrate.

As the functional decane compound, for example, 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2-amine can be exemplified. Propyltriethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyl Dimethoxydecane, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-B Oxycarbonyl-3-aminopropyltriethoxydecane, N-triethoxycarbenylpropyltriethylamine, N-trimethoxydecylpropyltriethylamine 10-trimethoxycarbamido-1,4,7-trioxane, 10-triethoxydecyl-1,4,7-trioxane, 9-trimethoxydecyl-3 6-Dimercaptoacetate, 9-triethoxydecyl-3,6-dimercaptoacetate, N-benzyl-3-aminopropyltrimethoxydecane, 9-trimethyl Methyl oxoalkyl-3,6-dicarboxylate, methyl 9-triethoxydecyl-3,6-dicarboxylate, N-benzyl-3-aminopropyltriethoxy Baseline, N-phenyl-3-aminopropyl Trimethoxydecane, N-phenyl-3-aminopropyltriethoxydecane, glycidoxymethyltrimethoxydecane, glycidoxymethyltriethoxydecane, 2-ring Oxypropoxyethyltrimethoxydecane, 2-glycidoxyethyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltrile Ethoxy decane and the like.

The ratio of use of the functional decane compound is preferably 2 parts by mass or less, more preferably 0.02 parts by mass to 0.2 parts by mass, per 100 parts by mass of the polymer [A].

<Preparation method of liquid crystal alignment agent>

The liquid crystal alignment agent contains the polymer [A] and the epoxy compound [B] as described above, and may contain an optional component as needed. Preferably, each component is dissolved in an organic solvent to prepare a composition.

Examples of the organic solvent include NMP, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy- 4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, B Glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate , diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, two Ethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethyl carbonate, propylene carbonate, and the like. These organic solvents may be used alone or in combination of two or more.

The solid content concentration of the liquid crystal alignment agent of the present invention, that is, the mass of all the components other than the solvent in the liquid crystal alignment agent, is a ratio of the total mass of the liquid crystal alignment agent, and is selected in consideration of viscosity, volatility, etc., preferably 1 Mass%~10% by mass. When the solid content concentration is less than 1% by mass, the thickness of the liquid crystal alignment film formed of the liquid crystal alignment agent is too small, and a satisfactory liquid crystal alignment film may not be obtained. On the other hand, when the solid content concentration exceeds 10% by mass, the film thickness of the coating film is too large, and a good liquid crystal alignment film may not be obtained, or the viscosity of the liquid crystal alignment agent may increase, and coating properties may be insufficient. The range of the preferable solid content concentration differs depending on the method used when the liquid crystal alignment agent is applied onto the substrate. For example, when the spin coating method is used, the solid content concentration is preferably from 1.5% by mass to 4.5% by mass. When the printing method is carried out, the solid content concentration is preferably from 3% by mass to 9% by mass, whereby the solution viscosity is from 12 mPa ‧ to 50 mPa ‧ s. When the inkjet method is used, the solid content concentration is preferably in the range of 1% by mass to 5% by mass, whereby the solution viscosity is in the range of 3 mPa‧s to 15 mPa‧s.

The temperature at which the liquid crystal alignment agent is prepared is preferably from 10 ° C to 50 ° C, more preferably from 20 ° C to 30 ° C.

<Liquid alignment film>

The liquid crystal alignment film of the present invention is formed of the liquid crystal alignment agent. Therefore, the liquid crystal alignment film can suppress deterioration in display quality due to deterioration of electrical properties and the like, and is easily peeled off during rework.

<Method of Forming Liquid Crystal Alignment Film>

In the liquid crystal alignment film of the present invention, a liquid crystal alignment agent is applied onto a substrate, and then the coated surface is heated to form a coating film on the substrate, and further subjected to a rubbing treatment in accordance with a desired display mode.

When a liquid crystal display element having a display mode of a TN type, an STN type or a VA type is manufactured, a pair of two substrates on which a patterned transparent conductive film is formed is formed, and on each of the transparent conductive film forming surfaces thereof, Preferably, the liquid crystal alignment agent is applied by a lithography method, a spin coating method, or an inkjet printing method, and then each coating surface is heated to form a coating film.

Examples of the substrate include a glass substrate such as floating glass or soda glass, polyethylene terephthalate, polybutylene terephthalate, polyether oxime, and polycarbonate (alicyclic). A transparent substrate of a plastic substrate such as an olefin).

The transparent conductive film provided on one surface of the substrate may, for example, be a NESA film formed of tin oxide (SnO ₂ ) (registered trademark of PPG, USA), and indium oxide-tin oxide (In ₂ O ₃ -SnO). ₂ ) An ITO film or the like formed.

The method of obtaining the patterned transparent conductive film may, for example, be a method of forming a pattern by photolithography after forming a transparent conductive film without a pattern; and forming a transparent conductive film, using a mask having a desired pattern. Method, etc. When the liquid crystal alignment agent is applied, in order to improve the adhesion between the surface of the substrate and the transparent conductive film and the coating film, a functional decane compound or a functional titanium compound may be preliminarily coated on the surface on which the coating film is formed on the substrate surface. .

After the liquid crystal alignment agent is applied, preheating (prebaking) is preferably performed for the purpose of preventing liquid dripping. The prebaking temperature is preferably from 30 ° C to 200 ° C, more preferably from 40 ° C to 150 ° C, and particularly preferably from 40 ° C to 100 ° C. In terms of prebaking time, it is preferably from 0.25 minutes to 10 minutes, more preferably from 0.5 minutes to 5 minutes.

Next, the solvent is completely removed, and sintering (post-baking) is performed for the purpose of thermally amidating the polyglycolic acid as needed. The post-baking temperature is preferably from 80 ° C to 300 ° C, more preferably from 120 ° C to 250 ° C. In terms of post-baking time, it is preferably from 5 minutes to 200 minutes, more preferably from 10 minutes to 100 minutes.

The film thickness of the coating film thus formed is preferably from 10 nm to 500 nm, more preferably from 10 nm to 200 nm.

When the manufacturing display mode is an IPS type liquid crystal display element, it is preferable to use a conductive film forming surface of a substrate on which a transparent conductive film forming a comb-shaped pattern is provided, and a surface of a counter substrate on which a conductive film is not provided. The liquid crystal alignment agent is applied by a lithography method, a spin coating method, or an inkjet printing method, and then a coating film is formed by heating each coated surface. The material of the substrate, the material of the transparent conductive film, the patterning method of the transparent conductive film, the pretreatment of the substrate, the heating method after applying the liquid crystal alignment agent, the preferred film thickness of the formed coating film, and the manufacturing display mode are TN type, STN The same applies to the case of the type or VA type liquid crystal display element.

When the display mode is a VA type liquid crystal display element, the coating film formed as described above can be directly used as a liquid crystal alignment film, and if necessary, the following rubbing treatment can be used.

When a liquid crystal display element other than the display mode VA type is manufactured, a liquid crystal alignment film is formed by rubbing the coating film formed as described above. The rubbing treatment is performed by rubbing a roll of a cloth formed of fibers such as nylon, rayon, or cotton onto the coating film surface formed as described above in a certain direction. Thereby, the alignment of the liquid crystal molecules can be imparted to the coating film to form a liquid crystal alignment film.

Then, the liquid crystal alignment film formed as above is treated, and the viewing angle property of the obtained liquid crystal display element can be improved by making each region of the liquid crystal alignment film have a different liquid crystal alignment film, wherein the processing on the liquid crystal film includes, for example, A process of irradiating a part of a liquid crystal alignment film with ultraviolet rays to change a pretilt angle of a partial region of the liquid crystal alignment film, as described in Japanese Laid-Open Patent Publication No. Hei 6-222366 In the case where a photoresist film is formed on a part of the surface of the liquid crystal alignment film, the rubbing treatment is performed in a direction different from the previous rubbing treatment, and the photoresist film is removed, as described in JP-A-5-107544.

<Liquid crystal display element>

The liquid crystal display element of the present invention has the liquid crystal alignment film. The liquid crystal display element is suitable for use in various devices, such as a clock, a portable game machine, a word processor, a notebook computer, a navigation system, a video recorder, a portable information terminal, a digital camera, a mobile phone, various monitors, and a liquid crystal. Used in display devices such as televisions.

<Method of Forming Liquid Crystal Display Element>

The liquid crystal display element of the present invention can be produced, for example, as follows. Two substrates for forming the liquid crystal alignment film were prepared, and liquid crystal cells were produced by disposing liquid crystal between the two substrates arranged in the opposite direction. Here, when the coating film is subjected to the rubbing treatment, the two substrates are disposed to face each other such that the rubbing directions of the respective coating films are at a predetermined angle to each other, for example, orthogonal or anti-parallel. When manufacturing a liquid crystal cell, the following two methods are mentioned, for example.

The first method is a currently known method. First, in order to arrange the liquid crystal alignment films in opposite directions, the two substrates are opposed to each other by a gap (hereinafter, also referred to as "cell gap"), and two sealants are used. The peripheral portion of the block substrate is bonded to each other, and after filling the liquid crystal into the cell gap divided by the surface of the substrate and the sealant, the injection hole is sealed to manufacture a liquid crystal cell.

The second method is a method called an ODF (One Drop Fill) method in which a predetermined position on one of two substrates forming a liquid crystal alignment film is coated with, for example, an ultraviolet curable sealing material, and then in a liquid crystal. After the liquid crystal is dropped on the alignment film surface, the other substrate is bonded and the liquid crystal alignment film is opposed to each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealing agent to produce a liquid crystal cell.

In the case of any of the methods, the liquid crystal cell produced as described above is reheated until the liquid crystals used have their isotropic temperatures, and then slowly cooled to room temperature to remove the flow alignment during liquid crystal injection. Then, the liquid crystal display element can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell.

The sealant may, for example, be an epoxy resin containing an alumina ball as a separator and a curing agent.

The liquid crystal may, for example, be a nematic liquid crystal or a smectic liquid crystal. Among them, a nematic liquid crystal is preferred. In the case of a VA type liquid crystal cell, a nematic liquid crystal having a negative dielectric anisotropy is preferred. Examples of such a liquid crystal include, for example, dicyanobenzene liquid crystals and ruthenium. Liquid crystal, Schiff base liquid crystal, oxygen azo liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, and the like. When it is a TN type liquid crystal cell or an STN type liquid crystal cell, a nematic liquid crystal having positive dielectric anisotropy is preferred. Examples of such a liquid crystal include a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal, a biphenylcyclohexane liquid crystal, a pyrimidine liquid crystal, and the like. An alkane liquid crystal, a bicyclooctane liquid crystal, a cubic liquid crystal, or the like. Further, in the liquid crystal, for example, a cholesteric liquid crystal such as cholesteryl chloride, cholesteryl phthalate or cholestyl carbonate may be added, and sold as "C-15" or "CB-15" (Merck). A chiral agent; a strong dielectric liquid crystal such as p-oxybenzylidene-p-amino-2-methylbutyl cinnamate or the like.

In the case of a polarizing plate which is bonded to the outer surface of the liquid crystal cell, a polarizing plate formed by a polarizing film called "H film" by sandwiching a polyvinyl alcohol with a cellulose acetate protective film and absorbing iodine may be mentioned. Or a polarizing plate formed of the H film itself.

<Polymer composition>

The polymer composition of the present invention comprises [A] at least one polymer selected from the group consisting of polyproline and polyimine, and [B] a quinone-containing ring represented by the above formula (I) Epoxy compound. The polymer composition is suitably used as a component such as a liquid crystal alignment agent for forming a liquid crystal alignment film. Further, the film formed of the polymer composition can also be used as an insulating film for electronic materials.

In the above formula (I), R ^A is a single bond or an alkanediyl group having 1 to 4 carbon atoms. R ^B is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic group, a divalent heterocyclic group, or a group formed by combining them. n is an integer of 0 or 1.

[Examples]

The invention is described in detail below based on the examples, but the description of the examples is not intended to limit the invention.

<Synthesis of polylysine>

[Synthesis Example 1]

98 g (0.50 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 109 g (0.50 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 198 g (1.0) as a diamine compound Mol) 4,4'-diaminophenylmethane was dissolved in a mixed solvent of 230 g of NMP and 2,060 g of γ-butyrolactone, and after reacting at 40 ° C for 3 hours, 1,350 g of γ-butyl was added. The lactone gave a solution containing 10% by mass of poly-proline (PA-1). The solution had a solution viscosity of 118 mPa ‧ s.

[Synthesis Example 2]

196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g (1.0 mol) of 2,2'-dimethyl-4 as a diamine compound 4'-diaminobiphenyl dissolved in a mixed solvent of 370 g of NMP and 3,300 g of γ-butyrolactone, and reacted at 40 ° C for 3 hours to obtain polyglycine (PA-2) The solution. The solution had a solution viscosity of 154 mPa ‧ s.

<Synthesis of Polyimine>

[Synthesis Example 3]

224 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 106 g (0.985 mol) of p-phenylenediamine and 7.8 g (0.015 mol) of 3 as a diamine compound The cholesteryl 5-diaminobenzoate was dissolved in 3,042 g of NMP and reacted at 60 ° C for 6 hours. The solution viscosity of the obtained polyaminic acid solution was 181 mPa ‧ s. Next, 3,380 g of NMP was added to the obtained polyaminic acid solution, and 395 g of pyridine and 306 g of acetic anhydride were added, and the mixture was dehydrated and closed at 110 ° C for 4 hours. After the imidization reaction, the solvent in the system was replaced with a new γ-butyrolactone solvent, and pyridine and acetic anhydride were removed to the outside of the system. Thus, a solution containing 15% by mass of a polyamidimide (PI-1) having a ruthenium iodide ratio of about 95% was obtained. A small amount of the obtained polyimine solution was added, and γ-butyrolactone was added to form a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 102 mPa·s.

[Synthesis Example 4]

110 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 160 g (0.50 mol) of 1,3,3a,4,5,9b-hexahydro-8- as tetracarboxylic dianhydride Methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, and 94 g (0.87 mol) as a diamine compound P-phenylenediamine, 25 g (0.10 mol) of 1,3-bis(3-aminopropyl)tetramethyldioxane and 9.6 g (0.015 mol) of 3,6-bis(4-aminobenzamide) Oxy)cholestane, 8.1 g (0.030 mol) of octadecylamine as a monoamine, was dissolved in 960 g of NMP, and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was added, and NMP was added thereto, and the viscosity of the solution having a solid concentration of 10% was measured and found to be 58 mPa·s. Next, 2,700 g of NMP was added to the obtained polyamic acid solution, 400 g of pyridine and 410 g of acetic anhydride were added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the system was replaced with a new γ-butyrolactone solvent, and pyridine and acetic anhydride were removed to the outside of the system. Thus, a solution containing about 15% by mass of polyamidimide (PI-2) having a ruthenium iodide ratio of 95% was obtained. A small amount of the obtained polyimine solution was added, and γ-butyrolactone was added to form a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 72 mPa·s.

[Synthesis Example 5]

226 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 76 g (0.80 mol) of p-phenylenediamine and 53 g (0.10 mol) of 3 as a diamine compound. The cholesteryl 5-diaminobenzoate and 100 g (0.2 mol) of cholestyloxy-2,4-diaminobenzene were dissolved in 1,820 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was added, and NMP was added thereto, and the viscosity of the solution having a solid concentration of 10% was measured and found to be 80 mPa·s. Next, 4,225 g of NMP was added to the obtained polyamic acid solution, 104 g of pyridine and 134 g of acetic anhydride were added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the system was replaced with a new NMP solvent, and pyridine and acetic anhydride were removed to the outside of the system. Thus, a solution containing about 15% by mass of polyamidimide (PI-3) having a ruthenium iodide ratio of 66% was obtained. A small amount of the obtained polyimine solution was added, and NMP was added to form a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 98 mPa·s.

[Synthesis Example 6]

224 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as a tetracarboxylic dianhydride and 87 g (0.80 mol) of p-phenylenediamine and 99 g (0.20 mol) of cholesteric as a diamine compound The alkoxy-2,4-diaminobenzene was dissolved in 1,848 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was added, and NMP was added thereto, and the viscosity of the solution having a solid concentration of 10% was measured and found to be 120 mPa·s. Next, 3,809 g of NMP was added to the obtained polyaminic acid solution, and 79 g of pyridine and 102 g of acetic anhydride were added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the system was replaced with a new NMP solvent, and pyridine and acetic anhydride were removed to the outside of the system. Thus, a solution containing about 15% by mass of polyamidimide (PI-4) having a ruthenium iodide ratio of 49% was obtained. A small amount of the obtained polyimine solution was added, and NMP was added to form a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 155 mPa·s.

[Synthesis Example 7]

224 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 76 g (0.70 mol) of p-phenylenediamine as a diamine compound, 40 g (0.20 mol) of 4, 4'-Diaminodiphenylmethane and 50 g (0.10 mol) of cholestyloxy-2,4-diaminobenzene were dissolved in 1,556 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was added, and NMP was added thereto, and the viscosity of the solution having a solid concentration of 10% was measured and found to be 133 mPa·s. Next, 3,614 g of NMP was added to the obtained polyaminic acid solution, and 79 g of pyridine and 102 g of acetic anhydride were added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with a new NMP solvent (by this operation, the pyridine and acetic anhydride used in the oxime imidization reaction are removed to the outside of the system), and a yield of about 15% by mass of ruthenium is obtained. A solution of 46% polyimine (PI-5). A small amount of the obtained polyimine solution was added, and NMP was added to form a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 133 mPa·s.

<Preparation of liquid crystal alignment agent (used in TN type liquid crystal display element)>

[Example 1]

Mixing a polyamine (PA-1)-containing solution as a polymer [A] with a polyimine (PI-1)-containing solution, and polymerizing proline (PA-1): polyimine (PI-1)=80:20 (mass ratio), to which γ-butyrolactone, NMP, and ethylene glycol monobutyl ether were added, and then added in an amount equivalent to 100 parts by mass based on the total amount of the polymer [A] 10 parts by mass of the formula (I-1-1), which is an example in which the epoxy compound [B] is exemplified by the above formula (I-1), and is sufficiently stirred to form a solvent. The composition was γ-butyrolactone: NMP: ethylene glycol mono-n-butyl ether = 71:17:12 (mass ratio), and a solid content concentration of 3.5% by mass. This solution was filtered using a filter having a pore size of 1 μm to prepare a liquid crystal alignment agent (S-1).

[Examples 2 to 13, Comparative Examples 1 to 12]

The types of the polymer [A] and the epoxy compound [B] and the amounts thereof used were as shown in Table 1, and the liquid crystal alignment agents (S-2) to (S-13) were prepared in the same manner as in Example 1. (CS-1) to (CS-12), which were used as Examples 2 to 13 and Comparative Examples 1 to 12, respectively.

Further, in the comparative examples, (G-1) to (G-3) used in correspondence with the epoxy compound [B] are as follows. Further, (I-1-4), (I-1-15), (I-1-16), and (I-2-6) in Table 1 mean the above formula (I-1) and formula, respectively. The compounds listed in the examples of (I-2).

G-1: N, N, N, 'N'-tetraepoxypropyl-m-xylyldiamine

G-2: N, N, N, 'N'-tetraepoxypropyl-4,4'-diaminodiphenylmethane

G-3: polyoxyethylene (5) phenylepoxypropyl ether (Nagase ChemteX, EX145)

<Preparation of liquid crystal alignment agent (for VA type liquid crystal display element)>

[Embodiment 14]

In a solution containing polyimine (PI-3) as the polymer [A], NMP and ethylene glycol mono-n-butyl ether are added, and then, in a total amount of 100 parts by mass relative to the [A] polymer, 10 parts by mass of the above (I-1-1) as the epoxy compound [B], sufficiently stirred to form a solvent composition of NMP: ethylene glycol mono-n-butyl ether = 60: 40 (mass ratio), solid content concentration It is a 3.5% by mass solution. This solution was filtered using a filter having a pore size of 1 μm to prepare a liquid crystal alignment agent (S-14).

[Examples 15 to 27, Comparative Examples 13 to 25]

The types of the polymer [A] and the epoxy compound [B] and the amounts thereof used were as shown in Table 1, and the liquid crystal alignment agents (S-15) to (S-27) were prepared in the same manner as in Example 14. (CS-13) to (CS-25), which were respectively referred to as Examples 15 to 27 and Comparative Examples 13 to 25.

<Manufacture of TN type liquid crystal display element>

[Example 28]

The liquid crystal alignment agent (S-1) was coated on a transparent conductive film made of an ITO film by a spin coater, which was set on one side of a glass substrate having a thickness of 1 mm, and on a hot plate at 80 ° C. The film was prebaked for 1 minute, and then heated at 200 ° C for 30 minutes to form a coating film having a film thickness of 80 nm. The coating film was rubbed with a roller having a roll of rayon cloth and a roll speed of 500 rpm, a platen moving speed of 3 cm/s, and a pile press length of 0.4 mm to impart liquid crystal alignment energy. Thereafter, ultrasonic cleaning was performed for 1 minute in ultrapure water, followed by drying in a dust-free oven at 100 ° C for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two pieces) of substrates having a liquid crystal alignment film. Next, an epoxy resin adhesive having a diameter of 5.5 μm is applied to each of the outer edges of the pair of substrates having the liquid crystal alignment film, and then the pressure is bonded to make the liquid crystal alignment film face opposite, and the adhesive is applied. hardening. Next, a nematic liquid crystal (Merck Corporation, MLC-6221) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to produce a liquid crystal cell, which was taken as an example. 28.

[Examples 29 to 40 and Comparative Examples 26 to 37]

The liquid crystal alignment agents (S-1) to (S-13) of Examples 1 to 13 and the liquid crystal alignment agents (CS-1) to (CS-12) of Comparative Examples 1 to 12 were used in the same manner as in Example 28. Liquid crystal display elements were produced, and these were referred to as Examples 29 to 40 and Comparative Examples 26 to 37.

<Manufacture of VA type liquid crystal display element>

[Example 41]

The liquid crystal alignment agent (S-14) was applied onto a transparent conductive film made of an ITO film by a spin coater, which was provided on one side of a glass substrate having a thickness of 1 mm, and on a hot plate at 80 ° C. The film was prebaked for 1 minute, and then heated at 210 ° C for 30 minutes to form a coating film (liquid crystal alignment film) having a film thickness of 80 nm. This operation was repeated to obtain a pair (two pieces) of substrates having a liquid crystal alignment film. Next, an epoxy resin adhesive having a diameter of 5.5 μm is applied to each of the outer edges of the pair of substrates having the liquid crystal alignment film, and then the pressure is bonded to make the liquid crystal alignment film face opposite, and the adhesive is applied. hardening. Next, a nematic liquid crystal (Merck Corporation, MLC-6608) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to produce a liquid crystal cell, which was taken as an example. 41.

[Examples 42 to 54 and Comparative Examples 38 to 50]

A liquid crystal display device was produced in the same manner as in Example 41 except that the liquid crystal alignment agents (S-14) to (S-27) and the liquid crystal alignment agents (CS-13) to (CS-25) of Comparative Examples 13 to 25 were used. These were taken as Examples 42 to 54 and Comparative Examples 38 to 50.

<evaluation>

The liquid crystal alignment elements of Examples 1 to 27 and Comparative Examples 1 to 25 and the liquid crystal display elements of Examples 28 to 54 and Comparative Examples 26 to 50 were subjected to the following evaluations.

[Measurement of peelability]

Each of the liquid crystal alignment agents of Examples 1 to 27 and Comparative Examples 1 to 25 was applied onto a transparent conductive film made of an ITO film by a spin coater, and the ITO film was provided on one surface of a glass substrate having a thickness of 1 mm. The film was prebaked at 100 ° C for 90 seconds on a hot plate to form a coating film having a film thickness of about 80 nm. This operation was repeated to manufacture two substrates having a coating film. Next, the obtained substrate was stored in a dark room at 25° C. under a nitrogen atmosphere, and after 12 hours and 72 hours, respectively, it was taken out from the dark room, and immersed in a beaker of NMP added at 40° C. for 2 minutes. After 2 minutes, the substrate was taken out from the beaker, washed several times with ultrapure water, and then water droplets were removed by air blowing, and the substrate was observed to observe the presence or absence of a residual coating film. After 72 hours, the film was taken out from the dark room, and no coating film remained after immersion in NMP, and the peeling property was good, and it was described as "○"; after 72 hours, the substrate taken out from the dark room could not be peeled off, but after 12 hours, the substrate taken out from the dark room was removed. It can be referred to as "△" which can be peeled off, and "X" which cannot be peeled off. The results are shown in Table 1.

[Measurement of voltage holding ratio]

The problem of deterioration of electrical properties related to deterioration in display quality was evaluated by the voltage holding ratio of the liquid crystal display element. Each of the liquid crystal display elements of Examples 28 to 54 and Comparative Examples 26 to 50 was applied with a voltage of 5 V at an application time of 60 μsec and an interval of 167 msec at 70 ° C, and then measured by VHR-1 manufactured by TOYO Technica Co., Ltd. The voltage holding ratio after the application was released to 167 msec was used as the initial voltage holding ratio (VH _1N ). Next, the liquid crystal cell after the initial voltage holding ratio was measured, and a weather resistance tester using a carbon arc as a light source was used, and light was irradiated for 1,000 hours. The liquid crystal display element after the light irradiation was again measured for the voltage holding ratio by the same method as described above, and this value was taken as the voltage holding ratio (VH _AF ) after the irradiation. The amount of decrease in voltage holding ratio obtained by VH _IN -VH _AF is defined as ΔVHR calculation.

In the TN type liquid crystal display elements (Examples 28 to 40 and Comparative Examples 26 to 37), when the voltage retention rate reduction amount ΔVHR is less than 7%, the reliability is referred to as "◎"; when it is 7% or more and less than 10%, The reliability is referred to as "○"; in the case of 10% or more, the reliability is referred to as "x".

In the VA type liquid crystal display device (Examples 41 to 54 and Comparative Examples 38 to 50), when the voltage retention rate reduction amount ΔVHR is less than 2.5%, the reliability is referred to as "◎"; when it is 2.5% or more and less than 5%, The reliability is referred to as "○"; in the case of 5% or more, the reliability is referred to as "x". The results are shown in Table 2.

As shown by the results of Tables 1 and 2, the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention can form a liquid crystal alignment film which is easily peeled off during rework. Further, it is also known that the liquid crystal display element of the present invention having the liquid crystal alignment film has a good voltage holding ratio in any of the TN type and VA type display modes, and the electrical properties are not deteriorated, and deterioration in display quality can be suppressed.

Industrial utilization possibility

According to the present invention, it is possible to form a liquid crystal alignment film which is suppressed from being deteriorated in display quality such as deterioration in electrical properties and which is easily peeled off during rework. The liquid crystal display element is suitable for use in various devices, such as a clock, a portable game machine, a word processor, a notebook computer, a navigation system, a video recorder, a portable information terminal, a digital code camera, a mobile phone, various monitors, Used in display devices such as LCD TVs. Further, the film formed of the polymer composition can also be used as an insulating film for electronic materials.

Claims (7)

A liquid crystal alignment agent comprising: [A] at least one polymer selected from the group consisting of polyproline and polyimine, and [B] a quinone imine represented by the following formula (I) a ring of monofunctional epoxy compounds, In the formula (I), R ^A is a single bond or an alkanediyl group having 1 to 4 carbon atoms; R ^B is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic group, and 2 valence. Heterocyclic groups, or a group in which they are combined; n is an integer of 0 or 1. The liquid crystal alignment agent of the first aspect of the invention, wherein the formula (I) is at least one selected from the group consisting of compounds represented by the following formulas (I-1) and (I-2), In the formula (I-1) and the formula (I-2), R ^A and the formula (I) have the same definition; and R ¹ , R ² and R ³ are each independently, and may include -O-, -COO-, - OCO- has a linear or branched alkyl group having 1 to 20 carbon atoms; in addition, R ¹ and R ² or R ¹ and R ² and R ³ may be bonded to each other to form part or all of a hydrogen atom. a ring structure that can be substituted; n is an integer of 0 or 1. The liquid crystal alignment agent of claim 1 or 2, wherein the [A] polymer is selected from the group consisting of polylysine and polyamidene formed by dehydration of the polyglycolic acid. At least one of the polyamic acid is synthesized using a tetracarboxylic dianhydride comprising 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxy-2 -carboxymethyl drop Selected from the group consisting of alkane-2:3,5:6-dianhydride and 2,4,6,8-tetracarboxybicyclo[3.3.0]-octane-2:4,6:8-dianhydride At least one. A liquid crystal alignment agent according to claim 1 or 2, wherein R ^A of the formula (I) is methanediyl. The liquid crystal alignment agent of claim 2, wherein in the formula (I-1) and the formula (I-2), R ¹ and R ² are bonded to each other to form a partial hydrogen atom or all of the benzene which may be substituted. ring. A liquid crystal alignment film formed by the liquid crystal alignment agent of any one of claims 1 to 5. A liquid crystal display element comprising the liquid crystal alignment film of claim 6 of the patent application.