CN106047373B

CN106047373B - Liquid crystal aligning agent

Info

Publication number: CN106047373B
Application number: CN201610141247.4A
Authority: CN
Inventors: 菅野尚基; 秋池利之; 冈田敬; 加藤孝人
Original assignee: JSR Corp
Current assignee: JSR Corp
Priority date: 2015-04-14
Filing date: 2016-03-14
Publication date: 2020-10-09
Anticipated expiration: 2036-03-14
Also published as: TWI801869B; JP7188533B2; JP7318787B2; TWI685514B; KR20160122636A; JP2023143921A; CN116590027A; JP2022017359A; TW201636382A; TW202132548A; KR102454059B1; JP2016200799A; JP6672815B2; CN111849511A; JP2020095286A; JP2023014150A; CN111849511B; JP7509286B2; TW202014509A; CN106047373A

Abstract

The invention provides a liquid crystal aligning agent, a liquid crystal alignment film and a liquid crystal element. The liquid crystal aligning agent contains a polymer component and at least one specific solvent selected from the group consisting of a solvent having a phosphorus atom, N-dimethylpropyleneurea, tetrahydro-4H-pyran-4-one, tetramethylene sulfoxide, 3-methylcyclohexanone, 4-methylcyclohexanone, a compound represented by the following formula (1), a compound represented by the following formula (2), a compound represented by the following formula (3), and a compound represented by the following formula (10). According to the present invention, a liquid crystal aligning agent which is less likely to swell a printing plate and has good printability can be obtained.

Description

Liquid crystal aligning agent

Technical Field

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

Background

Conventionally, various driving methods such as a Twisted Nematic (TN) type, a Super Twisted Nematic (STN) type, a Vertical Alignment (VA) type, an In-Plane Switching (IPS) type, a Fringe Field Switching (FFS) type, and an optically compensated bend (ocb) type have been developed for liquid crystal elements, which have different electrode structures and different properties of liquid crystal molecules used. These liquid crystal elements have a liquid crystal alignment film for aligning liquid crystal molecules. Polyamic acid, polyimide, or the like is used as a material of the liquid crystal alignment film in terms of satisfactory properties such as heat resistance, mechanical strength, and affinity for liquid crystal.

The liquid crystal alignment agent is prepared by dissolving a polymer component in a solvent, applying the liquid crystal alignment agent to a substrate, and heating the substrate to form a liquid crystal alignment film. As the solvent for the liquid crystal aligning agent, an organic solvent having high solubility in the polymer, for example, an aprotic polar solvent such as N-methyl-2-pyrrolidone or γ -butyrolactone, is generally used. In addition, in order to improve the coating property (printability) of the liquid crystal aligning agent when the liquid crystal aligning agent is coated on a substrate, an aprotic polar solvent and an organic solvent having a relatively low surface tension such as butyl cellosolve are used (for example, see patent document 1 or patent document 2).

As a method for applying the liquid crystal aligning agent to the substrate, various methods such as a spin coating method, an offset printing method, and an ink jet method are applied. For example, the offset printing method is generally performed using a transfer printing apparatus in which a liquid crystal aligning agent is applied to a printing plate containing a resin such as APR (registered trademark) and the liquid crystal aligning agent is transferred onto a substrate by the printing plate (for example, see patent document 3).

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent application laid-open No. 2010-97188

[ patent document 2] Japanese patent application laid-open No. 2010-156934

[ patent document 3] Japanese patent laid-open No. 2001-343649

Disclosure of Invention

[ problems to be solved by the invention ]

Butyl cellosolve, which is generally used for the purpose of improving the coatability of a liquid crystal aligning agent, tends to easily swell an APR resin. Therefore, when a liquid crystal alignment agent containing a butyl cellosolve is applied to a substrate by offset printing, the printing plate may swell and the printability may be reduced by repeating the application to the printing plate. Further, as a solvent component of the liquid crystal aligning agent, it is required that the polymer is not easily deposited on a printing machine even when printing is continuously performed and that the printability (continuous printability) is good.

The present invention has been made in view of the above problems, and an object thereof is to provide a liquid crystal aligning agent which hardly swells a printing plate and has good printability.

[ means for solving problems ]

The present inventors have conducted intensive studies to achieve the above-mentioned problems of the prior art, and as a result, have found that the above-mentioned problems can be solved by using a specific organic solvent as a solvent, and have completed the present invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film and liquid crystal element.

One aspect of the present invention provides a liquid crystal aligning agent comprising a polymer component and at least one specific solvent selected from the group consisting of a solvent having a phosphorus atom, N-dimethylpropyleneurea, tetrahydro-4H-pyran-4-one, tetramethylene sulfoxide, 3-methylcyclohexanone, 4-methylcyclohexanone, a compound represented by the following formula (1), a compound represented by the following formula (2), a compound represented by the following formula (3), and a compound represented by the following formula (10).

[ solution 1]

(in the formula (1), R⁴Is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; in the formula (2), R⁵Is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R⁶An alkanediyl group having 2 to 4 carbon atoms; in the formula (3), R⁷～R¹⁰Each independently a hydrogen atom or a monovalent organic group; in the formula (10), R¹¹～R¹³Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms)

By using the specific solvent as a solvent component of the liquid crystal aligning agent, a liquid crystal aligning agent in which the printing plate is not easily swelled can be obtained. Further, even when printing is continuously performed, the polymer is less likely to precipitate on the printer, and the printability is improved.

Another aspect of the present invention is to provide a liquid crystal alignment film formed of the liquid crystal aligning agent. In addition, another aspect is to provide a liquid crystal element including a liquid crystal alignment film formed of the liquid crystal alignment agent.

The liquid crystal alignment film of the present invention is formed by using the liquid crystal aligning agent containing the specific solvent, and therefore, a uniform coating film can be formed and the film quality is good. In addition, in the case of manufacturing a liquid crystal element using the liquid crystal aligning agent, printing defects can be reduced in the manufacturing process, and as a result, the yield of products can be improved.

Detailed Description

Hereinafter, each component contained in the liquid crystal aligning agent of the present invention and other components optionally blended as necessary will be described.

< Polymer component >

The liquid crystal aligning agent of the present invention contains a polymer component. The main skeleton of the polymer is not particularly limited, and examples thereof include: a main skeleton such as polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate, and the like. The term (meth) acrylate is intended to include both acrylates and methacrylates.

In the above polymer, the polymer component of the liquid crystal aligning agent is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane, in terms of the effect of the specific solvent on the improvement of printability being high. In addition, in the preparation of the liquid crystal aligning agent, one kind of the polymer may be used alone, or two or more kinds may be used in combination.

[ Polyamic acid ]

The polyamic acid in the present invention can be obtained by reacting tetracarboxylic dianhydride with diamine, for example.

(tetracarboxylic dianhydride)

Examples of tetracarboxylic dianhydrides used for the synthesis of polyamic acids include: aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, aromatic tetracarboxylic acid dianhydride, and the like. Specific examples of the tetracarboxylic acid dianhydride include aliphatic tetracarboxylic acid dianhydrides such as 1,2,3, 4-butanetetracarboxylic acid dianhydride;

examples of the alicyclic tetracarboxylic dianhydride include: 1,2,3, 4-cyclobutanetetracarboxylic dianhydride, 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 2,3, 5-tricarboxycyclopentylacetic dianhydride, 1,3,3a,4,5,9 b-hexahydro-5- (tetrahydro-2, 5-dioxo-3-furanyl) -naphtho [1,2-c ] anhydride]Furan-1, 3-dione, 1,3,3a,4,5,9 b-hexahydro-8-methyl-5- (tetrahydro-2, 5-diOxo-3-furyl) -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-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic anhydride, 3,5, 6-tricarboxyl-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, bicyclo [3.3.0]]Octane-2, 4,6, 8-tetracarboxylic acid 2:4,6: 8-dianhydride, 4, 9-dioxatricyclo [5.3.1.0^2,6]Undecane-3, 5,8, 10-tetraone, cyclohexanetetracarboxylic dianhydride, etc.;

examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic acid dianhydride; in addition, tetracarboxylic dianhydrides described in Japanese patent application laid-open No. 2010-97188 can be used. Further, the tetracarboxylic dianhydride may be used singly or in combination of two or more.

The tetracarboxylic dianhydride used for the synthesis preferably contains an alicyclic tetracarboxylic dianhydride in order to improve the electrical characteristics and to further improve the solubility of the polymer in a solvent containing a specific solvent and to further improve the effect of improving the printability. Further, among the alicyclic tetracarboxylic dianhydrides, it is preferable to contain at least one selected from the group consisting of 2,3, 5-tricarboxycyclopentylacetic dianhydride, 1,3,3a,4,5,9 b-hexahydro-5- (tetrahydro-2, 5-dioxo-3-furyl) -naphtho [1,2-c ] furan-1, 3-dione, 1,3,3a,4,5,9 b-hexahydro-8-methyl-5- (tetrahydro-2, 5-dioxo-3-furyl) -naphtho [1,2-c ] furan-1, 3-dione, bicyclo [3.3.0] octane-2, 4,6, 8-tetracarboxylic acid 2:4,6: 8-dianhydride and 1,2,3, 4-cyclobutanetetracarboxylic dianhydride, particularly preferably, the polyimide resin composition contains at least one selected from the group consisting of 2,3, 5-tricarboxycyclopentylacetic acid dianhydride, bicyclo [3.3.0] octane-2, 4,6, 8-tetracarboxylic acid 2:4,6: 8-dianhydride and 1,2,3, 4-cyclobutanetetracarboxylic acid dianhydride.

When at least one selected from the group consisting of 2,3, 5-tricarboxycyclopentylacetic acid dianhydride, bicyclo [3.3.0] octane-2, 4,6, 8-tetracarboxylic acid 2:4,6: 8-dianhydride, and 1,2,3, 4-cyclobutanetetracarboxylic acid dianhydride is contained as the tetracarboxylic acid dianhydride, the total content of these compounds is preferably 10 mol% or more, more preferably 20 mol% to 100 mol% based on the total amount of tetracarboxylic acid dianhydride used in the synthesis of polyamic acid.

(diamine)

Examples of the diamine used for the synthesis of the polyamic acid include: aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples of these diamines include aliphatic diamines such as: m-xylylenediamine, 1, 3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1, 3-bis (aminomethyl) cyclohexane, and the like; examples of the alicyclic diamine include 1, 4-diaminocyclohexane, 4' -methylenebis (cyclohexylamine), and the like;

examples of the aromatic diamine include: p-phenylenediamine, 4 '-diaminodiphenylmethane, 4' -diaminodiphenylsulfide, 1, 5-diaminonaphthalene, 2 '-dimethyl-4, 4' -diaminobiphenyl, 2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl, 4 '-diaminodiphenylether, 1, 3-bis (4-aminophenoxy) propane, 9-bis (4-aminophenyl) fluorene, 2-bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane, 4' - (p-phenylenediisopropylidene) dianiline, 1, 4-bis (4-aminophenoxy) benzene, 2, 6-diaminopyridine, 3, 6-diaminocarbazole, N, n' -bis (4-aminophenyl) -benzidine, 1, 4-bis- (4-aminophenyl) -piperazine, 1- (4-aminophenyl) -2, 3-dihydro-1, 3, 3-trimethyl-1H-indene-5-amine, 1- (4-aminophenyl) -2, 3-dihydro-1, 3, 3-trimethyl-1H-indene-6-amine, 3, 5-diaminobenzoic acid, cholestanyloxy-3, 5-diaminobenzene, cholestyryloxy-3, 5-diaminobenzene, cholestanyloxy-2, 4-diaminobenzene, cholestanyl alkyl 3, 5-diaminobenzoate, cholestanyl ester, Lanostanyl 3, 5-diaminobenzoate, 3, 6-bis (4-aminobenzoyloxy) cholestane, 4- (4' -trifluoromethoxybenzoyloxy) cyclohexyl-3, 5-diaminobenzoate, 1-bis (4- ((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1-bis (4- ((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, 2, 4-diamino-N, N-diallylaniline, 4-aminobenzylamine, N- [4- (2-aminoethyl) phenyl ] benzene-1, 4-diamine, N- [4- (aminomethyl) phenyl ] benzene-1, 4-diamine, diamine containing cinnamic acid structure and the following formula (D-1)

[ solution 2]

(in the formula (D-1), X^IAnd X^IIEach independently represents a single bond, -O-, -COO-, -OCO-or-NH-CO- (wherein the bond having the bond is bonded to the diaminophenyl group), R^IAnd R^IIIndependently represent alkanediyl having 1 to 3 carbon atoms, a represents 0 or 1, b represents an integer of 0 to 2, c represents an integer of 1 to 20, n represents 0 or 1, and m represents 0 or 1; wherein a and b are not 0 at the same time, in X^IIn the case of-NH-CO-, n is 0)

The compounds represented by the formula (I), etc.;

examples of the diaminoorganosiloxane include 1, 3-bis (3-aminopropyl) -tetramethyldisiloxane; in addition, diamines described in Japanese patent application laid-open No. 2010-97188 can be used. These diamines may be used singly or in combination of two or more.

Specific examples of the compound represented by the formula (D-1) include compounds represented by the following formulae (D-1-1) to (D-1-4).

[ solution 3]

The diamine used for the synthesis of the polyamic acid preferably contains 30 mol% or more, more preferably 50 mol% or more, and particularly preferably 80 mol% or more of the aromatic diamine based on the total diamine.

(Synthesis of Polyamic acid)

The polyamic acid can be obtained by reacting the tetracarboxylic dianhydride as described above with a diamine, optionally together with a molecular weight modifier. The ratio of the tetracarboxylic dianhydride to the diamine used in the synthesis reaction of the polyamic acid is preferably 0.2 to 2 equivalents of the acid anhydride group of the tetracarboxylic dianhydride to 1 equivalent of the amino group of the diamine. Examples of the molecular weight modifier include: maleic anhydride, phthalic anhydride, itaconic anhydride and other acid monoanhydrides; monoamine compounds such as aniline, cyclohexylamine and n-butylamine; and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. The use ratio of the molecular weight modifier is preferably 20 parts by weight or less based on 100 parts by weight of the total of the tetracarboxylic dianhydride and the diamine used.

The synthesis reaction of the polyamic acid is preferably carried out in an organic solvent. The reaction temperature in this case is preferably-20 ℃ to 150 ℃ and the reaction time is preferably 0.1 hour to 24 hours.

Examples of the organic solvent used in the reaction include: aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and the like. Particularly preferred as the organic solvent is one or more selected from the group consisting of N-methyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, γ -butyrolactone, tetramethylurea, hexamethylphosphoric triamide, m-cresol, xylenol, halogenated phenol, and a specific solvent described below, or a mixture of one or more of these solvents and another organic solvent (e.g., butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount (a) of the organic solvent used is preferably such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50 wt% relative to the total amount (a + b) of the reaction solution.

The reaction solution obtained by dissolving the polyamide acid was obtained as described above. The reaction solution may be directly provided for the preparation of the liquid crystal aligning agent, or may be provided for the preparation of the liquid crystal aligning agent after the polyamic acid contained in the reaction solution is separated.

[ polyimide ]

The polyimide in the present invention can be obtained by, for example, subjecting a polyamic acid synthesized in the above-described manner to dehydrative ring closure and imidization. The polyimide may be a complete imide compound obtained by dehydration ring closure of the entire amic acid structure of the polyamic acid as a precursor thereof, or may be a partial imide compound obtained by dehydration ring closure of only a part of the amic acid structure so that the amic acid structure and the imide ring structure coexist. The imidization ratio of the polyimide in the present invention is preferably 30% or more, more preferably 40% to 99%, and still more preferably 50% to 99%. The imidization ratio is a ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of the polyimide, and is expressed as a percentage. Here, a part of the imide ring may be an imide ring.

The dehydration ring closure of the polyamic acid is preferably performed by the following method: a method of heating the polyamic acid; or a method in which the polyamic acid is dissolved in an organic solvent, a dehydrating agent and a dehydration ring-closure catalyst are added to the solution, and heating is carried out as necessary. Among them, the latter method is preferably used.

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

A reaction solution containing polyimide was obtained in the manner described. The reaction solution can be directly provided for the preparation of the liquid crystal aligning agent, can also be provided for the preparation of the liquid crystal aligning agent after the dehydrating agent and the dehydration ring-closing catalyst are removed from the reaction solution, and can also be provided for the preparation of the liquid crystal aligning agent after the polyimide is separated. These purification operations may be carried out according to known methods. In addition, the polyimide may be obtained by imidization of a polyamic acid ester.

[ Polyamic acid ester ]

The polyamic acid ester in the present invention can be obtained, for example, by the following method: [I] a method of reacting the polyamic acid obtained by the synthesis reaction with an esterifying agent (for example, methanol or ethanol, N-dimethylformamide diethylacetal, or the like); [ II ] a method in which a tetracarboxylic acid diester and a diamine are reacted in an organic solvent in the presence of an appropriate dehydration catalyst (for example, 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholinium halide, phosphorus-based condensing agent, etc.); [ III ] A method of reacting a tetracarboxylic acid diester dihalide with a diamine in an organic solvent in the presence of an appropriate base (for example, pyridine, triethylamine, sodium hydroxide, etc.), and the like.

The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. The reaction solution in which the polyamic acid ester is dissolved may be supplied directly to the production of the liquid crystal aligning agent, or may be supplied to the production of the liquid crystal aligning agent after the polyamic acid ester contained in the reaction solution is separated.

The polyamic acid, polyamic acid ester, and polyimide obtained in the above manner are preferably those having a solution viscosity of 10 to 800 mPas, more preferably 15 to 500 mPas, when prepared into a solution having a concentration of 10% by weight. The solution viscosity (mPa · s) of the polymer is a value measured at 25 ℃ using an E-type rotational viscometer for a10 wt% concentration polymer solution prepared using a good solvent for the polymer (e.g., γ -butyrolactone, N-methyl-2-pyrrolidone, etc.).

The polyamic acid, polyamic acid ester, and polyimide contained in the liquid crystal aligning agent of the present invention preferably have a weight average molecular weight in terms of polystyrene measured by Gel Permeation Chromatography (GPC) of 500 to 100,000, more preferably 1,000 to 50,000.

[ polyorganosiloxane ]

The polyorganosiloxane in the present invention can be obtained by, for example, hydrolyzing or hydrolyzing and condensing a hydrolyzable silane compound preferably in the presence of an appropriate organic solvent, water and a catalyst.

Examples of the hydrolyzable silane compound used for synthesizing the polyorganosiloxane include: alkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trimethoxysilylpropylsuccinic anhydride, dimethyldimethoxysilane, and dimethyldiethoxysilane; nitrogen and sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N- (3-cyclohexylamino) propyltrimethoxysilane; epoxy group-containing silane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltriethoxysilane, and 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane; and unsaturated bond-containing alkoxysilane compounds such as 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth) acryloyloxypropylmethyldiethoxysilane, vinyltrimethoxysilane and p-vinyltrimethoxysilane. The hydrolyzable silane compound may be used alone or in combination of two or more of these silane compounds. Further, "(meth) acryloyloxy" means to include "acryloyloxy" and "methacryloyloxy".

The hydrolysis and condensation reaction is carried out by reacting one or more silane compounds as described above with water, preferably in the presence of an appropriate catalyst and an organic solvent. During the reaction, the proportion of water used is preferably 1 to 30 moles based on 1 mole of the silane compound (total amount). Examples of the catalyst used include: acids, alkali metal compounds, organic bases (for example, triethylamine, tetramethylammonium hydroxide, etc.), titanium compounds, zirconium compounds, and the like. The amount of the catalyst to be used varies depending on the kind of the catalyst, reaction conditions such as temperature, and the like, and is suitably set, for example, preferably from 0.01 to 3 times by mol based on the total amount of the silane compounds. Examples of the organic solvent used include hydrocarbons, ketones, esters, ethers, alcohols, and the like, and among these organic solvents, a water-insoluble or poorly water-soluble organic solvent is preferably used. The organic solvent is preferably used in a proportion of 50 to 1,000 parts by weight based on 100 parts by weight of the total silane compounds used in the reaction.

The hydrolysis/condensation reaction is preferably carried out by heating with an oil bath or the like, for example. In this case, the heating temperature is preferably 130 ℃ or lower, and the heating time is preferably 0.5 to 12 hours. After the reaction is completed, the organic solvent layer separated from the reaction solution is removed of the solvent to obtain polyorganosiloxane.

When the polyorganosiloxane is used as a liquid crystal aligning agent for TN, STN, or vertical alignment liquid crystal display devices, a specific group such as a liquid crystal aligning group or a group having a photo-aligning structure may be introduced into a side chain of the polyorganosiloxane. The method for synthesizing the polyorganosiloxane having these specific groups in the side chain is not particularly limited, and examples thereof include the following methods: and a method in which an epoxy group-containing silane compound or a mixture of an epoxy group-containing silane compound and another silane compound is subjected to hydrolytic condensation to synthesize an epoxy group-containing polyorganosiloxane, and the obtained epoxy group-containing polyorganosiloxane is reacted with a carboxylic acid having the specific group. The reaction of the epoxy group-containing polyorganosiloxane with the carboxylic acid can be carried out according to a known method.

The weight average molecular weight (Mw) of the polyorganosiloxane as measured by GPC in terms of polystyrene is preferably in the range of 500 to 100,000, more preferably in the range of 1,000 to 30,000, and still more preferably in the range of 1,000 to 20,000. When the weight average molecular weight of the polyorganosiloxane is in the above range, handling is easy in the production of a liquid crystal alignment film, and the obtained liquid crystal alignment film has sufficient material strength and properties.

In the liquid crystal aligning agent of the present invention, the content ratio (the total amount in the case of containing two or more kinds) of the polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane is preferably 50% by weight or more, and more preferably 60% by weight or more, relative to the total amount of the polymer components in the liquid crystal aligning agent. In addition, from the viewpoint of more preferably obtaining the effects of the present invention, the polymer component preferably contains at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide. The total content of the polyamic acid, polyamic acid ester, and polyimide in the liquid crystal alignment agent is preferably 40% by weight or more, and more preferably 60% by weight or more, based on the total amount of the polymer components in the liquid crystal alignment agent.

< solvent >

The liquid crystal aligning agent of the present invention is a liquid composition in which a polymer component is dispersed or dissolved in a solvent. The liquid crystal aligning agent contains, as a solvent, at least one specific solvent selected from the group consisting of a solvent having a phosphorus atom (hereinafter also referred to as "phosphorus-containing solvent"), N-dimethylpropyleneurea, tetrahydro-4H-pyran-4-one, tetramethylene sulfoxide, 3-methylcyclohexanone, 4-methylcyclohexanone, a compound represented by the formula (1), a compound represented by the formula (2), a compound represented by the formula (3), and a compound represented by the formula (10).

[ phosphorus-containing solvent ]

The phosphorus-containing solvent is not particularly limited as long as it is a compound having at least one phosphorus atom in the molecule, and is preferably at least one selected from the group consisting of compounds represented by the following formulae (P-1) to (P-4).

[ solution 4]

(in the formulae (p-1) to (p-4), X¹And Y¹Each independently is an oxygen atom or a sulfur atom; r¹Is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, R²Is a hydrogen atom or a monovalent organic group; wherein R is¹And R²May be bonded to each other to form a ring; r³Each independently hydrogen or C1-C6 alkyl, two R bonded to nitrogen³Nitrogen-containing heterocyclic groups which may be bonded to each other to form a monovalent group together with the nitrogen atom; wherein R is¹And R²Not simultaneously being a hydrogen atom, R²And R³Not being hydrogen atoms at the same time; m, n, k and j are each independently an integer of 1 to 3; in the case where m, n, k, j are 2 or 3, a plurality of R in the formula¹、R³The R's may be the same or different from each other, and when m, n, k and j are 1, a plurality of R's in the formula²May be the same or different from each other)

Here, the term "hydrocarbon group" as used herein includes chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. The "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group that are composed of only a chain structure, without including a cyclic structure in the main chain. The unsaturated polyester resin may be saturated or unsaturated. The "alicyclic hydrocarbon group" refers to a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not an aromatic ring structure. The alicyclic hydrocarbon group is not necessarily composed of only the structure of the alicyclic hydrocarbon, and includes a hydrocarbon group having a chain structure in a part thereof. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. The aromatic ring structure is not necessarily composed of only an aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may be included in a part thereof. In the present specification, the term "organic group" refers to a group containing a carbon atom, and may contain a hetero atom in the structure.

In the formula (p-1), R¹Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms include: a straight or branched alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; alkenyl groups such as vinyl and allyl; alkynyl groups such as ethynyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, and methylcyclohexyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl, phenethyl, and styryl. In the radical, R¹Preferably an alkyl group having 1 to 3 carbon atoms.

R²Examples of the monovalent organic group include: a monovalent hydrocarbon group having 1 to 10 carbon atoms, a group containing a hetero atom between carbon-carbon bonds of the hydrocarbon group, and a compoundA group in which a hydrocarbon group and a hetero atom-containing group are bonded, a group in which at least one hydrogen atom of these groups is substituted with a substituent, a cyano group, a formyl group, and the like.

Here, the heteroatom-containing group means a divalent or higher group having a heteroatom, and examples thereof include: -O-, -CO-, -COO-, -CONR^a-(R^aHydrogen atom or C1-6 alkyl group, the same shall apply hereinafter), -NR^a-trivalent nitrogen atom, -NR^aCONR^a-、-OCONR^a-、-S-、-COS-、-OCOO-、-SO₂-and the like. Examples of the substituent include: halogen atom, nitro group, cyano group, hydroxyl group and the like. In the radical, R²Preferred is an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 or 7 carbon atoms.

R³The alkyl group having 1 to 6 carbon atoms may be either straight or branched. Two R³Examples of the monovalent nitrogen-containing heterocyclic group bonded to each other include a group obtained by removing a hydrogen atom bonded to a nitrogen atom of the nitrogen-containing heterocyclic group. Specific examples of the nitrogen-containing heterocyclic ring include a pyridine ring, a piperidine ring and the like, and these ring portions may have a substituent such as a halogen atom or an alkyl group. R³Preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. X¹And Y¹Preferred is an oxygen atom. m, n, k and j are preferably 2 or 3, more preferably 3.

In the formulae (p-1) to (p-4), the phosphorus-containing solvent is preferably at least one selected from the group consisting of the compound represented by the formula (p-1) and the compound represented by the formula (p-3), and more preferably the compound represented by the formula (p-1), from the viewpoint of further improving the effect of improving printability.

Preferable specific examples of the phosphorus-containing solvent include compounds represented by the following formulae (p-1-1) to (p-1-7), formula (p-3-1), and formula (p-3-2).

[ solution 5]

Among the above-mentioned compounds, the phosphorus-containing solvents are particularly preferably those represented by the above-mentioned formulae (p-1-1) to (p-1-4) and (p-3-1), respectively, from the viewpoint of more satisfactory printability. Further, the phosphorus-containing solvent may be used singly or in combination of two or more.

[ Compound represented by the formula (1) ]

In the formula (1), R⁴Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, and butyl groups, and these alkyl groups may be straight or branched. Specific examples of the compound represented by the above formula (1) include 4-formylmorpholine and 4-acetylmorpholine, and among them, 4-formylmorpholine is particularly preferable. Further, the compounds represented by the formula (1) may be used singly or in combination of two or more.

[ Compound represented by the formula (2) ]

In the formula (2), R⁵Examples of the C1-6 alkyl group in (1) can be given by R⁴And (4) description. R⁶Examples of the alkanediyl group having 2 to 4 carbon atoms include an ethylene group, a propylene group and a butylene group, and these alkanediyl groups may be straight or branched. Specific examples of the compound represented by the formula (2) include: 3-methyl-2-oxazolidinone, 3-ethyl-2-oxazolidinone, 3-isopropyl-2-oxazolidinone, N-methyl-2-oxazolidinone (oxazinone), and the like, and among them, 3-methyl-2-oxazolidinone is particularly preferable. Further, the compounds represented by the formula (2) may be used singly or in combination of two or more.

[ Compound represented by the formula (3) ]

In the formula (3), R⁷～R¹⁰Examples of the monovalent organic group include: an alkyl group having 1 to 10 carbon atoms, a group containing a heteroatom-containing group between carbon-carbon bonds of the alkyl group, a group in which the alkyl group is bonded to the heteroatom-containing group, a group in which at least one hydrogen atom of these groups is substituted with a substituent, and the like. As to specific examples of the hetero atom-containing group and the substituent, R in the formula (p-1) can be applied²And (4) description. Furthermore, R⁷～R¹⁰May be the same or different from each other. R⁷～R¹⁰Preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or-COR^b(R^bHydrogen atom or C1-3 alkyl group). R⁷And R¹⁰One of them is preferably-COR^b。

Specific examples of the compound represented by the above formula (3) include 2-furaldehyde, 3-furaldehyde, 5-methyl-2-furaldehyde, 5-methyl-3-furaldehyde, 4-methyl-2-furaldehyde, 5-hydroxymethyl-2-furaldehyde and the like, and among them, 5-methyl-2-furaldehyde is particularly preferable. Further, the compounds represented by the formula (3) may be used singly or in combination of two or more.

[ Compound represented by the formula (10) ]

In the formula (10), R¹¹～R¹³Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group and an isopropyl group, and among them, a methyl group is preferable. Specific examples of the compound represented by the formula (10) include lactamide, N-dimethyl lactamide, N-diethyl lactamide, N-methyl-N-propyl lactamide, N-ethyl lactamide, N-isopropyl lactamide, etc., and among them, N-dimethyl lactamide is particularly preferable. Further, the compound represented by the formula (10) may be used singly or in combination of two or more.

Among the above-mentioned compounds, the specific solvent is preferably at least one selected from the group consisting of a phosphorus-containing solvent, N-dimethylpropyleneurea, the compound represented by the formula (1), and the compound represented by the formula (2) in terms of more favorable printability (particularly continuous printability). Further, the specific solvent may be used singly or in combination of two or more.

[ other solvents ]

The liquid crystal aligning agent of the present invention may contain a solvent other than the specific solvent (hereinafter, also referred to as "other solvent"). Specific examples of the other solvents include: n-ethyl-2-pyrrolidone, N- (N-propyl) -2-pyrrolidone, N-isopropyl-2-pyrrolidone, N- (N-butyl) -2-pyrrolidone, N- (tert-butyl) -2-pyrrolidone, N- (N-pentyl) -2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, 3-butoxy-N, N-dimethylpropane amide, 3-methoxy-N, N-dimethylpropane amide, 3-hexyloxy-N, N-dimethylpropane amide, N-isopropylpyrrolidone, N- (N-butyl) -2-pyrrolidone, N- (tert-butyl) -2-pyrrolidone, N- (N-pentyl) -2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxy, isopropoxy-N-isopropyl-propionamide, N-butoxy-N-isopropyl-propionamide, 1, 3-dimethyl-2-imidazolidinone, N' -dimethylpropyleneurea, tetramethylurea, N-methyl-2-pyrrolidone, gamma-butyrolactone, -valerolactone, gamma-caprolactone, N-diethylacetamide, gamma-butyrolactam, N-dimethylformamide, N-dimethylacetamide, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene 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 monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, ethylene carbonate, propylene carbonate, and the like. Further, other solvents may be used singly or in combination of two or more of the compounds.

The specific solvent may be all or a part of the solvent contained in the liquid crystal aligning agent. The content ratio of the specific solvent (the total amount thereof in the case of using two or more types, the same applies hereinafter) is preferably 1 to 80% by weight, more preferably 5 to 70% by weight, still more preferably 10 to 60% by weight, and particularly preferably 20 to 60% by weight, based on the total amount of the solvents contained in the liquid crystal aligning agent.

< other ingredients >

The liquid crystal aligning agent of the present invention contains the polymer component and the solvent as described above, and may contain other components as required. Examples of the other components include: a compound having at least one epoxy group in the molecule, a functional silane compound, a photopolymerizable compound, a surfactant, a filler, an antifoaming agent, a sensitizer, a dispersant, an antioxidant, an adhesion promoter, an antistatic agent, a leveling agent, an antimicrobial agent, and the like. The blending ratio of these components can be appropriately set in a range not to impair the effect of the present invention, depending on the compound to be blended.

The concentration of the solid component in the liquid crystal aligning agent of the present invention (the ratio of the total weight of the components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility and the like, and is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the surface of a substrate as described below, and preferably heated to form a coating film as a liquid crystal alignment film or a coating film to be a liquid crystal alignment film, but in this case, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent tends to increase to lower the coating properties.

The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spin coating method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5 wt%. In the case of using the offset printing method, it is particularly preferable to set the solid content concentration to a range of 3 to 9% by weight and thereby set the solution viscosity to a range of 12 to 50mPa · s. In the case of using the ink jet method, it is particularly preferable to set the solid content concentration to a range of 1 to 5% by weight and thereby set the solution viscosity to a range of 3 to 15mPa · s. The temperature at the time of preparing the liquid crystal aligning agent is preferably 10 to 50 ℃ and more preferably 20 to 30 ℃.

< liquid crystal alignment film and liquid crystal cell >

The liquid crystal alignment film of the present invention is formed from the liquid crystal aligning agent prepared in the manner described. The liquid crystal element of the present invention further includes a liquid crystal alignment film formed using the liquid crystal alignment agent. The driving mode of the liquid crystal in the liquid crystal element is not particularly limited, and can be applied to various driving modes such as TN type, STN type, IPS type, FFS type, VA type, Multi-domain vertical Alignment (MVA) type, and Polymer Sustained Alignment (PSA) type. The liquid crystal element of the present invention can be manufactured by a method including, for example, the following steps 1 to 3. In step 1, the substrate used differs depending on the desired driving mode. The steps 2 and 3 are common to each drive mode.

[ step 1: formation of coating film ]

First, the liquid crystal aligning agent of the present invention is applied to a substrate, and then the coated surface is heated, thereby forming a coating film on the substrate.

(1-1) in the case of producing a TN-type, STN-type, VA-type, MVA-type, or PSA-type liquid crystal cell, a pair of two substrates each provided with a patterned transparent conductive film is used, and a liquid crystal alignment agent is applied to the surface of each substrate on which the transparent conductive film is formed, preferably by an offset printing method, a spin coating method, a roll coating method, or an ink jet printing method. The substrate may be, for example: float glass, soda glass, and the like; transparent substrates comprising plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin). As the transparent conductive film provided on one surface of the substrate, a film containing tin oxide (SnO) can be used₂) A Nessel (NESA) film (registered trademark of PPG corporation, USA) containing indium oxide-tin oxide (IN)₂O₃-SnO₂) Indium Tin Oxide (ITO) film, and the like.

After the liquid crystal alignment agent is applied, it is preferable to perform preliminary heating (pre-baking) for the purpose of preventing dripping of the applied alignment agent. The pre-baking temperature is preferably 30 ℃ to 200 ℃, and the pre-baking time is preferably 0.25 minutes to 10 minutes. Thereafter, a calcination (post-baking) step is performed for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amic acid structure present in the polymer. The calcination temperature (post-baking temperature) at this time is preferably 80 to 300 ℃ and the post-baking time is preferably 5 to 200 minutes. The film thickness of the film formed in this manner is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5. mu.m.

(1-2) in the case of producing an IPS type or FFS type liquid crystal display device, a liquid crystal aligning agent is applied to one surface of a substrate provided with electrodes including a transparent conductive film or a metal film patterned in a comb-tooth type and a counter substrate not provided with the electrodes, and then the respective applied surfaces are heated to form a coating film. The materials, coating methods, heating conditions after coating, film thicknesses, and the like of the substrate and the transparent conductive film used in this case are the same as those in the above (1-1). As the metal film, for example, a film containing a metal such as chromium can be used.

In both cases (1-1) and (1-2), a liquid crystal alignment film or a coating film to be a liquid crystal alignment film is formed by applying a liquid crystal alignment agent to a substrate and then removing the organic solvent.

[ step 2: orientation ability imparting treatment

In the case of manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, a treatment of imparting liquid crystal aligning ability to the coating film formed in the above step 1 is performed. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. Examples of the orientation ability imparting treatment include: rubbing treatment in which a coating film is rubbed in a certain direction by a roller wrapped with a cloth made of fibers such as nylon, rayon, and cotton, and photo-alignment treatment in which the coating film is irradiated with polarized or unpolarized radiation. On the other hand, in the case of producing a VA-type liquid crystal display element, the coating film formed in the step 1 may be used as it is as a liquid crystal alignment film, or the film may be subjected to an alignment ability imparting treatment. The liquid crystal alignment film preferred for the VA type liquid crystal display element can also be preferably used for the psa (polymer sustained alignment) type liquid crystal display element.

[ step 3: construction of liquid Crystal cell

Two substrates on which liquid crystal alignment films are formed in this manner are prepared, and liquid crystal is disposed between the two substrates disposed in opposition to each other, thereby manufacturing a liquid crystal cell. For manufacturing a liquid crystal cell, for example, there are: (1) a method of arranging two substrates facing each other with a gap therebetween so that the liquid crystal alignment films face each other, bonding peripheral portions of the two substrates to each other with a sealant, filling a liquid crystal into a cell gap defined by the surfaces of the substrates and the sealant, and sealing the filling hole; (2) a method (One Drop Fill (ODF) method) in which a sealant is applied to a predetermined position on One of the substrates on which the liquid crystal alignment film is formed, liquid crystal is dropped onto predetermined several positions on the surface of the liquid crystal alignment film, and then the other substrate is bonded so that the liquid crystal alignment film faces each other, and the liquid crystal is spread over the entire surface of the substrate. The liquid crystal cell produced is preferably further heated to a temperature at which the liquid crystal used exhibits an isotropic phase, and then gradually cooled to room temperature to remove the flow alignment during filling of the liquid crystal.

For the sealant, for example, an epoxy resin containing a hardener and alumina balls as spacers (spacers) can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and among them, nematic liquid crystal is preferable, and for example: schiff base (Schiff base) liquid crystals, azoxy (azoxy) liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane (cubane) liquid crystals, and the like. In addition, for example, a cholesteric liquid crystal (cholesteric liquid crystal), a chiral agent, a ferroelectric liquid crystal, or the like may be added to these liquid crystals.

In the case of manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as described above, except for the aspect of injecting or dropping a photopolymerizable compound together with liquid crystal. Then, the liquid crystal cell is irradiated with light while a direct-current or alternating-current voltage is applied between the conductive films of the pair of substrates. In the case where a coating film is formed on a substrate using a liquid crystal aligning agent containing a photopolymerizable compound, a liquid crystal cell may be constructed in the same manner as described above, and then the liquid crystal cell may be irradiated with light while applying a direct current or alternating current voltage between conductive films provided on a pair of substrates.

The liquid crystal display element of the present invention can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include: a polarizing plate formed by sandwiching a polarizing film called "H film" formed by absorbing iodine while extending and orienting polyvinyl alcohol, or a polarizing plate including the H film itself with a cellulose acetate protective film.

The liquid crystal element of the present invention can be effectively applied to various devices, for example, to: a timepiece, a portable game machine, a word processor, a notebook Personal computer, a car navigation system, a camcorder, a Personal Digital Assistant (PDA), a digital camera, a mobile phone, a smart phone, various monitors, various display devices such as a liquid crystal television, a light adjusting film, and the like. Further, a liquid crystal element formed using the liquid crystal aligning agent of the present invention can be applied to a retardation film.

[ examples ]

The present invention will be further specifically described below with reference to examples, but the present invention is not limited to these examples.

The solution viscosity, imidization ratio of polyimide, weight average molecular weight, and epoxy equivalent of each polymer solution in the synthesis examples were measured by the following methods.

[ solution viscosity (mPas) of the polymer solution ] A solution adjusted to a polymer concentration of 10% by weight using a predetermined solvent was measured at 25 ℃ using an E-type rotational viscometer.

[ imidization ratio of polyimide]Adding polyimide solution into pure water, drying the obtained precipitate at room temperature under reduced pressure, dissolving in deuterated dimethyl sulfoxide, measuring at room temperature with tetramethylsilane as reference substance¹H-nuclear magnetic resonance (¹H-Nuclear Magnetic Resonance，¹H-NMR). According to what is obtained¹H-NMR spectrum, the imidization rate [% ] was determined by the following equation (1)]。

Imidization rate [% ]]＝(1-A¹/A²×α)×100…(1)

(in the numerical formula (1), A¹Is a peak from a proton of an NH group appearing in the vicinity of a chemical shift of 10ppmArea, A²α is the ratio of the number of other protons to one proton of NH group in the precursor (polyamic acid) of the polymer, which is the peak area derived from other protons

The weight average molecular weight Mw of the polymer is a polystyrene equivalent value measured by gel permeation chromatography under the following conditions.

Pipe column: TSKgelGRCXLII manufactured by Tosoh (Strand, Tosoh)

Solvent: tetrahydrofuran (THF)

Temperature: 40 deg.C

Pressure: 68kgf/cm²

[ epoxy equivalent ] was measured by the hydrochloric acid-methylethylketone method described in Japanese Industrial Standards (JIS) C2105.

< Synthesis of Polymer >

Synthetic example 1: synthesis of polyimide (PI-1)

22.4g (0.1 mol) of 2,3, 5-tricarboxycyclopentylacetic dianhydride (TCA) as tetracarboxylic dianhydride, 8.6g (0.08 mol) of p-Phenylenediamine (PDA) as diamine, and 10.5g (0.02 mol) of cholestanyl 3, 5-diaminobenzoate (HCDA) were dissolved in 166g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ℃ for 6 hours to obtain a solution containing 20% by weight of polyamic acid. A small amount of the obtained polyamic acid solution was collected, NMP was added thereto to prepare a solution having a polyamic acid concentration of 10% by weight, and the solution viscosity was measured to be 90 mPas.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7 wt%, and 11.9g of pyridine and 15.3g of acetic anhydride were added thereto to carry out a dehydration ring-closure reaction at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was subjected to solvent substitution with fresh NMP (pyridine and acetic anhydride used in the dehydration ring-closure reaction were removed to the outside of the system by this operation, the same applies hereinafter), whereby a solution containing polyimide (PI-1) having an imidization rate of about 68% by weight of 26% was obtained. A small amount of the obtained polyimide solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10% by weight, and the solution viscosity was measured to be 45 mPas. Then, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyimide (PI-1).

[ Synthesis example 2: synthesis of polyimide (PI-2)

22.5g (0.1 mol) of TCA as tetracarboxylic dianhydride, 7.6g (0.07 mol) of PDA as diamine, 5.2g (0.01 mol) of HCDA and 4.0g (0.02 mol) of 4,4' -diaminodiphenylmethane (DDM) were dissolved in 157g of NMP and reacted at 60 ℃ for 6 hours to obtain a solution containing 20 wt% of polyamic acid. A small amount of the obtained polyamic acid solution was collected, NMP was added thereto to prepare a solution having a polyamic acid concentration of 10% by weight, and the solution viscosity was measured to be 110 mPas.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7 wt%, and 16.6g of pyridine and 21.4g of acetic anhydride were added to conduct a dehydration ring-closure reaction at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was subjected to solvent substitution with fresh NMP to obtain a solution containing polyimide (PI-2) having an imidization rate of about 82% at 26 wt%. A small amount of the obtained polyimide solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10% by weight, and the solution viscosity was measured to be 62 mPas. Then, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyimide (PI-2).

[ Synthesis example 3: synthesis of polyimide (PI-3)

24.9g (0.10 mol) of bicyclo [3.3.0] octane-2, 4,6, 8-tetracarboxylic acid 2:4,6: 8-dianhydride (BODA) as tetracarboxylic dianhydride, 8.6g (0.08 mol) of PDA and 10.4g (0.02 mol) of hcdad as diamine were dissolved in NMP176g, and a reaction was carried out at 60 ℃ for 6 hours to obtain a solution containing 20 wt% of polyamic acid. A small amount of the obtained polyamic acid solution was collected, NMP was added thereto to prepare a solution having a polyamic acid concentration of 10% by weight, and the solution viscosity was measured to be 103 mPas.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7 wt%, and 11.9g of pyridine and 15.3g of acetic anhydride were added thereto to carry out a dehydration ring-closure reaction at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was subjected to solvent substitution with fresh NMP to obtain a solution containing polyimide (PI-3) having an imidization rate of about 71% at 26 wt%. A small amount of the obtained polyimide solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10% by weight, and the solution viscosity was measured to be 57 mPas. Then, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyimide (PI-3).

[ Synthesis example 4: synthesis of polyimide (PI-4)

110g (0.50 mol) of TCA and 160g (0.50 mol) of 1,3,3a,4,5,9 b-hexahydro-8-methyl-5- (tetrahydro-2, 5-dioxo-3-furyl) naphtho [1,2-c ] furan-1, 3-dione as tetracarboxylic dianhydride, 25g (0.10 mol) of PDA91g as diamine, 25g (0.10 mol) of 1, 3-bis (3-aminopropyl) tetramethyldisiloxane and 25g (0.040 mol) of 3, 6-bis (4-aminobenzoyloxy) cholestane as diamine, and 1.4g (0.015 mol) of aniline as monoamine were dissolved in NMP960g and reacted at 60 ℃ for 6 hours, thereby obtaining a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was collected, NMP was added thereto to prepare a solution having a polyamic acid concentration of 10% by weight, and the solution viscosity was measured to be 60 mPas.

Then, 2,700g of NMP was added to the obtained polyamic acid solution, and 390g of pyridine and 410g of acetic anhydride were added thereto to carry out a dehydration ring-closure reaction at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was subjected to solvent substitution with fresh γ -butyrolactone, thereby obtaining about 2,500g of a solution containing polyimide (PI-4) having an imidization rate of 15% by weight of about 95%. A small amount of the solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10 wt%, and the solution viscosity was measured to be 70mPa · s. Then, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyimide (PI-4).

[ Synthesis example 5: synthesis of polyimide (PI-5)

22.4g (0.1 mol) of TCA as tetracarboxylic dianhydride, 8.6g (0.08 mol) of PDA as diamine, 2.0g (0.01 mol) of DDM2 and 3.2g (0.01 mol) of 2,2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl were dissolved in 324g of NMP and reacted at 60 ℃ for 4 hours to obtain a solution containing 10% by weight of polyamic acid.

Then, 360g of NMP was added to the obtained polyamic acid solution, and 39.5g of pyridine and 30.6g of acetic anhydride were added to conduct a dehydration ring-closure reaction at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was subjected to solvent substitution with fresh NMP to obtain a solution containing polyimide (PI-5) having an imidization rate of about 93% by weight of 10%. A small amount of the obtained polyamic acid solution was collected, and the solution viscosity was measured to be 30 mPas. Then, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyimide (PI-5).

[ Synthesis example 6: synthesis of polyimide (PI-6)

A polyamic acid solution was obtained in the same manner as in synthesis example 1, except that the diamine used was changed to 0.08 mol of 3, 5-diaminobenzoic acid (3,5DAB) and 0.02 mol of cholestanyloxy-2, 4-diaminobenzene (HCODA). A small amount of the obtained polyamic acid solution was collected, NMP was added thereto to prepare a solution having a polyamic acid concentration of 10% by weight, and the solution viscosity was measured to be 80 mPas.

Then, imidization was performed by the same method as in synthesis example 1 to obtain a solution containing polyimide (PI-6) having an imidization rate of 26 wt% of about 65%. A small amount of the obtained polyimide solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10% by weight, and the solution viscosity was measured to be 40 mPas. Then, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyimide (PI-6).

[ Synthesis example 7: synthesis of Polyamic acid (PA-1)

200g (1.0 mol) of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride (CB) as tetracarboxylic dianhydride and 210g (1.0 mol) of 2,2 '-dimethyl-4, 4' -diaminobiphenyl as diamine were dissolved in a mixed solvent of 370g of NMP and 3,300g of gamma-butyrolactone, and a reaction was carried out at 40 ℃ for 3 hours to obtain a polyamic acid solution having a solid content of 10% by weight and a solution viscosity of 160 mPas. Then, the polyamic acid solution was injected into excess methanol to precipitate a reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyamic acid (PA-1).

[ Synthesis example 8: synthesis of Polyamic acid (PA-2)

A polyamic acid solution having a solid content of 10 wt% and a solution viscosity of 170mPa · s was obtained in the same manner as in synthesis example 7, except that the tetracarboxylic dianhydride used was pyromellitic dianhydride (PMDA)0.9 mol and CB 0.1 mol, and the diamine was PDA 0.2 mol and 4,4' -diaminodiphenyl ether (DDE)0.8 mol. Then, the polyamic acid solution was injected into excess methanol to precipitate a reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyamic acid (PA-2).

[ Synthesis example 9: synthesis of Polyamic acid (PA-3)

7.0g (0.031 mole) of TCA as a tetracarboxylic dianhydride and 13g (1 mole relative to 1 mole of TCA) as a diamine compound represented by the following formula (R-1) were dissolved in 80g of NMP and reacted at 60 ℃ for 4 hours to obtain a solution containing 20 wt% of polyamic acid (PA-3). The solution viscosity of the polyamic acid solution was 2,000mPa · s. Further, the compound represented by the following formula (R-1) is synthesized according to the description of Japanese patent laid-open publication No. 2011-100099. Then, the polyamic acid solution was injected into excess methanol to precipitate a reaction product. The precipitate was washed with methanol and dried at 40 ℃ for 15 hours under reduced pressure, thereby obtaining polyamic acid (PA-3).

[ solution 6]

[ Synthesis example 10: synthesis of polyorganosiloxane (ASP-1) ]

100.0g of 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane (ECETS), 500g of methyl isobutyl ketone and 10.0g of triethylamine were put into a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, and mixed at room temperature. Then, 100g of deionized water was added dropwise over 30 minutes using a dropping funnel, and the reaction was carried out at 80 ℃ for 6 hours while stirring under reflux. After the reaction was completed, the organic layer was taken out, washed with a 0.2 wt% ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure, whereby the reactive polyorganosiloxane (EPS-1) was obtained as a viscous transparent liquid. The reactive polyorganosiloxane (EPS-1) is subjected to¹As a result of H-NMR analysis, an epoxy-based peak having a theoretical intensity was obtained in the vicinity of chemical shift () (3.2 ppm), and it was confirmed that no side reaction of an epoxy group occurred in the reaction. The resulting reactive polyorganosiloxane had a weight average molecular weight Mw of 3,500 and an epoxy equivalent of 180 g/mole.

Then, 10.0g of reactive polyorganosiloxane (EPS-1), 30.28g of methyl isobutyl ketone as a solvent, 3.98g of 4-dodecyloxybenzoic acid as a reactive compound, and 0.10g of UCAT 18X (trade name, manufactured by Santo Apro Co., Ltd.) as a catalyst were put into a 200mL three-necked flask, and the reaction was carried out with stirring at 100 ℃ for 48 hours. After completion of the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed with water three times, the organic layer was dried over magnesium sulfate, and the solvent was distilled off, whereby 9.0g of liquid crystal alignment polyorganosiloxane (ASP-1) was obtained. The weight average molecular weight Mw of the resulting polymer was 9,900.

[ Synthesis example 11: synthesis of polyorganosiloxane (PS1)

31g of p-vinyltrimethoxysilane, 70g of tetrahydrofuran, 33g of triethylamine and 25g of deionized water were added to a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, and mixed at room temperature. Then, the reaction was carried out at 60 ℃ for 3 hours under reflux with stirring. After completion of the reaction, the organic layer was taken out, and 60g of diethylene glycol diethyl ether was added thereto and concentrated by heating. The mixture was concentrated until the solid content concentration became 30%, whereby a diethylene glycol diethyl ether solution of polyorganosiloxane (PS1) was obtained.

Synthesis examples 12 and 13

A diethylene glycol diethyl ether solution of polyorganosiloxane (PS2) and polyorganosiloxane (PS3) was obtained by the same synthesis method as in synthesis example 11, except that the charged raw materials were as shown in table 1 below. The weight-average molecular weight Mw of the obtained polyorganosiloxane is shown in table 1 below.

[ Table 1]

In table 1, the abbreviations of the raw silane compounds are as follows.

STTMS: p-styryl trimethoxy silane

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

PTMS: phenyltrimethoxysilane

[ example 1]

< preparation of liquid Crystal Aligning agent >

Using polyimide (PI-1) as a polymer, trimethyl Phosphate (PTM), N-methyl-2-pyrrolidone (NMP) and Butyl Cellosolve (BC) were added thereto as a solvent to prepare a solution having a solvent composition of PTM: NMP: BC of 20:40:40 (weight ratio) and a solid content of 6.5 wt%. The solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal aligning agent (S-1). The liquid crystal aligning agent (S-1) is mainly used for the production of a vertical alignment type liquid crystal display device.

< evaluation of swelling Property of printing plate >

The liquid crystal aligning agent (S-1) was used to evaluate the swelling easiness (swelling property) of the APR plate. The APR plate is a resin plate formed of a liquid photosensitive resin partially cured by ultraviolet irradiation, and is generally used for a printing plate of a liquid crystal alignment film printing machine. The fact that the APR plate is not easily swelled when the liquid crystal aligning agent is brought into contact with the APR plate means that: the liquid crystal aligning agent is not easy to be soaked into an APR plate during printing, and the printing performance is good. The swelling property was evaluated by immersing the APR plate in the liquid crystal aligning agent for 1 day and measuring the change in weight of the APR plate before and after the immersion. In this case, when the increase rate of the weight of the APR plate (swelling rate) is less than 4%, the APR plate is less likely to swell and evaluated as good (o), and when the increase rate is 4% or more, the APR plate is more likely to swell and evaluated as bad (x). As a result, in the above examples, the swelling ratio was 3.5%, and the swelling property was "good (∘)". The swelling degree was calculated by using the following numerical formula (2).

Swelling rate [% ]]＝(W²-W¹)/W¹)×100…(2)

(in the numerical formula (2), W¹Weight of APR plate before immersion, W²For weight of APR version after impregnation)

< evaluation of printability >

With respect to the liquid crystal aligning agent (S-1) prepared as described above, printability (continuous printability) when printing was continuously performed on a substrate was evaluated. Evaluation was performed in the following manner. First, a liquid crystal alignment film printer (manufactured by japan portrait printer ("stock"), en gustero (Angstrom) form "S40L-532") was used to print the liquid crystal alignment agent (S-1) on the transparent electrode surface of the glass substrate with the transparent electrode including the ITO film under the condition that the amount of the liquid crystal alignment agent dropped onto the anilox roller was set to 20 drops (about 0.2g) to and fro. Printing on the substrate was performed 20 times while using a new substrate at 1 minute intervals.

Then, the liquid crystal aligning agent (S-1) was dispensed (single pass) onto the anilox roller at 1 minute intervals, and at that time, an operation of bringing the anilox roller into contact with a printing plate (hereinafter referred to as idle operation) was performed 10 times in total (during this time, printing on the glass substrate was not performed). The idle operation is an operation performed for intentionally printing the liquid crystal alignment agent under severe conditions.

After 10 idle runs, main printing was subsequently performed using a glass substrate. In the main printing, 5 substrates were put at 30-second intervals after idling, and each of the substrates after printing was heated at 80 ℃ for 1 minute (prebaking) to remove the solvent, and then heated at 200 ℃ for 10 minutes (postbaking) to form a coating film having a thickness of about 80 nm. The coating film was observed with a microscope at 20-fold magnification to evaluate the printability (continuous printability). For the evaluation, the case where no deposition of the polymer was observed in the first main printing after the idle operation was defined as "good continuous printability" (o), the case where no deposition of the polymer was observed in the first main printing after the idle operation but no deposition of the polymer was observed during the execution of 5 main printing was defined as "good continuous printability" (Δ), and the case where deposition of the polymer was observed after the repetition of 5 main printing was defined as "poor continuous printability" (x). As a result, the continuous printability "good (∘)" in the examples. In addition, it is experimentally found that in a liquid crystal aligning agent having good printability, the deposition of a polymer during continuous feeding of a substrate is improved (disappears). Further, the number of times of idling was changed to 15 times, 20 times, and 25 times, and the printability of the liquid crystal aligning agent was evaluated in the same manner as described above, and as a result, in the above example, "good (. smallcircle)" was obtained when idling was set to 15 times and 20 times, and "fair (. DELTA)" was obtained when idling was set to 25 times.

Examples 2 to 31 and comparative examples 1 to 5

Liquid crystal aligning agents (S-2) to (S-31) and liquid crystal aligning agents (SR-1) to (SR-5) were prepared in the same manner as in example 1, except that the types and compositions of the polymer and the solvent used were changed as described in Table 2 below. In addition, regarding each liquid crystal aligning agent, swelling characteristics and printability of the printing plate were evaluated in the same manner as in example 1. The results of these evaluations are shown in table 2 below.

[ Table 2]

In table 2, the use ratio (weight ratio) of each polymer to 100 parts by weight of the total amount of the polymers used is shown for those using two polymers as polymer components (examples 18 to 31). Of the liquid crystal aligning agents, (S-2) to (S-17), (SR-1) to (SR-5) are mainly used for the production of vertical alignment liquid crystal display devices, (S-18) to (S-23) are mainly used for the production of TN liquid crystal display devices, (S-24) are mainly used for the production of IPS liquid crystal display devices, (S-29) to (S-31) are mainly used for the production of vertical alignment liquid crystal display devices by the photo-alignment method, and (S-25) to (S-28) are mainly used for the production of PSA liquid crystal display devices. In table 2, the numerical values of the solvent composition indicate the blending ratio (weight ratio) of each compound to the total amount of the solvents used for the preparation of the liquid crystal aligning agent (the same applies to tables 3 to 5 below). The symbols of the solvent composition are as follows.

a: phosphoric acid trimethyl ester

b: phosphoric acid triethyl ester

c: hexamethylphosphoric triamide

d: n-methyl-2-pyrrolidone

e: n-ethyl-2-pyrrolidone

f: gamma-butyrolactone

g: gamma-valerolactone

h: -valerolactone

i: n, N-diethyl acetamide

j: butyl cellosolve

k: diethylene glycol diethyl ether

l: propylene glycol monomethyl ether acetate

[ examples 32 to 52]

Liquid crystal aligning agents (S-32) to (S-52) were prepared in the same manner as in example 1, except that the types and compositions of the polymer and the solvent used were changed as described in table 3 below. In addition, regarding each liquid crystal aligning agent, swelling characteristics and printability of the printing plate were evaluated in the same manner as in example 1. The results of these evaluations are shown in table 3 below.

[ Table 3]

Table 3 also shows the use ratio (weight ratio) of each polymer to 100 parts by weight of the total amount of the polymers used, for those using two polymers as the polymer components (examples 40 to 43, and examples 50 to 52). Of the liquid crystal aligning agents, (S-32) to (S-39) and (S-44) to (S-49) are mainly used for the production of vertical alignment type liquid crystal display elements, and (S-40) to (S-43) and (S-50) to (S-52) are mainly used for the production of TN type liquid crystal display elements. In table 3, the symbols of the solvent composition are as follows. d and j are the same as in table 2.

m: n, N-dimethyl propylene urea

n: 4-formyl morpholine

o: 3-methyl-2-oxazolidinones

p: tetrahydro-4H-pyran-4-ones

r: tetramethylene sulfoxide

s: 3-methylcyclohexanone

t: 4-methylcyclohexanone

Example 53 to example 56

Liquid crystal aligning agents (S-53) to (S-56) were prepared in the same manner as in example 1, except that the polymer component and the type and composition of the solvent used were changed as described in table 4 below. In addition, regarding each liquid crystal aligning agent, swelling characteristics and printability of the printing plate were evaluated in the same manner as in example 1. The results of these evaluations are shown in table 4 below.

[ Table 4]

In table 4, the use ratio (weight ratio) of each polymer to 100 parts by weight of the total amount of the polymers used is shown for those using two polymers as the polymer components (example 55, example 56). Of the liquid crystal aligning agents, (S-53) and (S-54) are mainly used for the production of a vertical alignment type liquid crystal display device, and (S-55) and (S-56) are mainly used for the production of a TN type liquid crystal display device. In table 4, the symbols of the solvent composition are as follows. d and j are the same as in table 2.

q: 5-methyl-2-furaldehyde

u: n, N-Dimethyllactamide (a compound represented by the following formula (10-1))

[ solution 7]

[ examples 57 to 60]

Liquid crystal aligning agents (S-57) to (S-60) were prepared in the same manner as in example 1, except that the types and compositions of the polymer and the solvent used were changed as described in table 5 below. In addition, regarding each liquid crystal aligning agent, swelling characteristics and printability of the printing plate were evaluated in the same manner as in example 1. The results of these evaluations are shown in table 5 below. In table 5, the numerical values in the column of the polymer components indicate the use ratio (weight ratio) of each polymer relative to 100 parts by weight of the total amount of the polymers used. The symbols (d, m, j) of the solvent compositions are the same as those in tables 2 and 3.

[ Table 5]

From the results, it is understood that the liquid crystal aligning agents (examples 1 to 60) containing the specific solvents hardly swell the printing plate and have good continuous printability. On the other hand, the swelling property and continuous printability of the liquid crystal aligning agent of the comparative example containing no specific solvent were inferior to those of the examples.

Claims

1. A liquid crystal aligning agent comprising:

a polymer component comprising a polymer having a polymer chain,

compounds represented by the following formulae (p-1-3) to (p-1-7), and

at least one other solvent selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ -butyrolactone, γ -valerolactone, N-diethylacetamide, butyl cellosolve, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate,

2. the liquid crystal aligning agent according to claim 1, wherein the polymer component comprises at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane.

3. The liquid crystal aligning agent according to claim 1 or 2, wherein the content ratio of the compound represented by the formulae (p-1-3) to (p-1-7) is 1 to 80% by weight relative to the total amount of the solvent in the liquid crystal aligning agent.