TWI658065B - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

An object of the present invention is to suppress a film thickness failure at an end portion of a coating region of a liquid crystal alignment agent. The present invention provides a liquid crystal alignment agent containing at least one polymer (A) selected from the group consisting of polyamidic acid, polyamidate, and polyimide, and a solvent, and the solvent contains : A specific solvent (X), which is 1-butoxy-2-propanol; and a specific solvent (Y), which is selected from the group consisting of diethylene glycol diethyl ether, diacetone alcohol, propylene glycol diacetate, and dipropylene glycol At least one of the groups consisting of monomethyl ether.

Description

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

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element. In particular, the present invention relates to a liquid crystal alignment agent for achieving narrow frame, and a liquid crystal alignment film manufactured using the liquid crystal alignment agent, and includes the same. Liquid crystal display element of liquid crystal alignment film.

In the past, liquid crystal display elements have developed various driving methods such as electrode structures, physical properties of liquid crystal molecules used, and manufacturing steps, such as the known twisted nematic (TN) type or super twisted nematic (Super Twisted Nematic). , STN) type, Vertical Alignment (VA) type, In-Plane Switching (IPS) type, Fringe Field Switching (FFS) type, Polymer stabilized alignment (PSA) ) Type and other liquid crystal display elements. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. In terms of various characteristics such as heat resistance, mechanical strength, and affinity with liquid crystals, polyamic acid or polyimide is generally used as a material of the liquid crystal alignment film.

In the liquid crystal alignment agent, a polymer component such as polyamic acid or polyimide is dissolved in a solvent, and the liquid crystal alignment agent is coated on a substrate and heated to form a liquid crystal alignment film. Conventionally, the method of applying a liquid crystal alignment agent to a substrate is usually The method using an offset printing apparatus here has a disadvantage that coating unevenness tends to occur with the recent enlargement of liquid crystal panels. Therefore, in order to solve the above-mentioned problems, in recent years, a coating method using an inkjet method has been introduced into the manufacturing steps of large-scale liquid crystal panels. In addition, along with this, various liquid crystal alignment agents have been proposed for application to coating by an inkjet method (for example, refer to Patent Documents 1 and 2).

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-10899

[Patent Document 2] Japanese Patent Laid-Open No. 2009-300465

According to the application by the inkjet method, it is possible to reduce the uneven application of the liquid crystal alignment agent when manufacturing a large-scale liquid crystal panel. On the other hand, at the end of the application area, due to sag or coating The amount is insufficient, and there is a disadvantage that the film thickness is easily reduced. The poor film thickness causes the display unevenness of the liquid crystal panel. Therefore, in large liquid crystal panels, the quality of the display area has been ensured by designing the panel frame to be wide in the past. However, in recent years, narrower frames have been required for the purpose of further improving the quality of liquid crystal panels. In order to achieve the narrower frames, liquid crystal alignment agents are also required to be further improved.

The present invention has been made in view of the problems described above, and a main object thereof is to provide a liquid crystal alignment agent capable of suppressing poor film thickness at an end portion of a coating region.

The inventors of the present invention conducted active research in order to achieve the problems of the prior art as described above, and as a result, found that a specific compound is added as a liquid crystal alignment A part of the solvent component of the agent can solve the above problems and complete the present invention. Specifically, the present invention provides the following liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element.

One aspect of the present invention is to provide a liquid crystal alignment agent, which contains at least one polymer (A) and a solvent selected from the group consisting of polyamic acid, polyamidate, and polyimide, and The solvent contains: a specific solvent (X), which is 1-butoxy-2-propanol; and a specific solvent (Y), which contains a solvent selected from the group consisting of diethylene glycol diethyl ether, diacetone alcohol, and propylene glycol diacetate. And at least one of the group consisting of dipropylene glycol monomethyl ether.

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

According to the liquid crystal alignment agent of the present invention, by including the specific solvent (X) and the specific solvent (Y) in the liquid crystal alignment agent, it is possible to narrow the area where the film thickness defect occurs in the end portion of the coating area as much as possible. . In addition, since the liquid crystal display element of the present invention has a liquid crystal alignment film formed by using the liquid crystal alignment agent of the present invention, it is difficult to cause display unevenness due to poor film thickness at the end portion of the liquid crystal alignment film, and narrow frames can be realized. Into. This makes it possible to ensure a display area as large as possible with respect to the size of the support (frame) of the display portion. In addition, when used as a multi-display, the non-display area between the displays can be reduced as much as possible.

The liquid crystal alignment agent of the present invention contains at least one polymer (A), a specific solvent (X), and a specific solvent (Y) selected from the group consisting of polyamidic acid, polyamidate, and polyimide. ). Hereinafter, each component contained in the liquid crystal aligning agent of this invention, and other components arbitrarily mix | blended as needed are demonstrated.

<Polymer (A): Polyamic acid>

The polyamic acid as the polymer (A) of the present invention can be obtained by reacting a tetracarboxylic dianhydride with a diamine compound.

[Tetracarboxylic dianhydride]

Examples of the tetracarboxylic dianhydride used to synthesize the polyamic acid of the present invention include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. As specific examples of these tetracarboxylic dianhydrides, examples of the aliphatic tetracarboxylic dianhydride include 1, 2, 3, 4-butane tetracarboxylic dianhydride, and the like; and examples of the alicyclic tetracarboxylic dianhydride include : 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (Tetrahydro-2,5-dioxo-3-furyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-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- Furyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-di Anhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] Monoalkane-3,5,8,10-tetraketone, cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, etc .; Examples of aromatic tetracarboxylic dianhydride: pyromelite dianhydride Other than that, tetracarboxylic dianhydride described in Japanese Patent Laid-Open No. 2010-97188 can be used. The tetracarboxylic dianhydrides may be used alone or in combination of two or more.

From the viewpoints of transparency and solubility in a solvent, the tetracarboxylic dianhydride used for the synthesis preferably contains an alicyclic tetracarboxylic dianhydride. The alicyclic tetracarboxylic dianhydride preferably contains a compound selected from the group consisting of 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (Tetrahydro-2,5-dioxo-3-furyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -8-methyl-5- (tetrahydro-2,5-dioxo-3-furyl) -naphtho [1,2-c] furan-1,3-dione, 2,4,6, 8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, And at least one of the group consisting of cyclopentanetetracarboxylic dianhydride, and more preferably selected from the group consisting of 2,3,5-tricarboxycyclopentylacetic dianhydride, 2,4,6,8-tetracarboxylic group Bicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, and cyclopentane At least one of the group consisting of tetracarboxylic dianhydride (hereinafter also referred to as a specific tetracarboxylic dianhydride).

In the case where the specific tetracarboxylic dianhydride is included as the tetracarboxylic dianhydride used for synthesis, the specific tetracarboxylic dianhydride relative to the total amount of the tetracarboxylic dianhydride used to synthesize polyamino acid is The total content is preferably 10 mol% or more, more preferably 20 mol% to 100 mol%, and even more preferably 50 mol% to 100 mol%.

[Diamine compound]

Examples of the diamine compound used to synthesize the polyamidic acid of the present invention include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, and a diamine organosiloxane. As specific examples of these diamine compounds, examples of the aliphatic diamine include meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, Hexamethylene diamine and the like; Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine), and 1,3-bis (amine Methyl) cyclohexane and the like; examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1 2,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diamine Benzene, 2,7-diaminophosphonium, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9- Bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoro Propane, 4,4 '-(p-phenylene diisopropyl) bisaniline, 4,4'-(m-phenylene diisopropyl) bisaniline, 1,4-bis (4-amino (Phenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine , 3,6-diaminoacridine, 3 , 6-diaminoxazole, N-methyl-3,6-diaminoxazole, N-ethyl-3,6-diaminoxazole, N-phenyl-3,6-diamine Oxazole, N, N'-bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, 1, 4-bis- (4-aminophenyl) -pyrazine, 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, cholesterol Alkoxy-3,5-diaminobenzene, cholestoxy-3,5-diaminobenzene, cholesteroxy-2,4-diaminobenzene, cholestoxy-2 1,4-Diaminobenzoic acid, Cholesteryl 3,5-diaminobenzoate, Cholesteryl 3,5-diaminobenzoate, Lanostane 3,5-diaminobenzoate Ester, 3,6-bis (4-aminobenzyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4'-trifluoro (Methoxybenzyloxy) cyclohexyl-3,5-diaminobenzoate, 4- (4'-trifluoromethylbenzyloxy) cyclohexyl-3,5-diamine Benzoate, 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) phenyl) 4- (4-heptylcyclohexyl) cyclohexane, 2,4-diamino-N, N-diallylaniline, 4-aminobenzylamine, 3-aminobenzylamine, 1 , 3-diamino-4-octadecyloxybenzene, 3- (3,5-diaminobenzyloxy) cholestane, 3,6-bis (4-aminobenzylhydrazone) (Oxy)) cholestane, and the following formula (D-1)

(In the formula (D-1), X ^I and X ^II are each independently a single bond, -O-, -COO-, or -OCO-, and R ^I and R ^II are each independently an alkane group having 1 to 3 carbon atoms. Base, a is 0 or 1, b is an integer from 0 to 2, c is an integer from 1 to 20, and n is 0 or 1, where a and b will not be 0 at the same time)

Represented compounds and the like; examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisilaxane, etc. In addition, Japanese Patent Laid-Open The diamine described in 2010-97188.

The divalent group represented by "-X ^I- (R ^I -X ^II ) _n- " in the formula (D-1) is preferably an alkanediyl group having 1 to 3 carbon atoms, * -O-, * -COO- or * -OC ₂ H ₄ -O- (wherein the bond with "*" is bonded to the diaminophenyl group).

Specific examples of the group "-C _c H _{2c + 1} " include, for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, N-decyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecane Group, n-eicosyl, etc. The two amino groups in the diaminophenyl group are preferably located at the 2,4-position or the 3,5-position with respect to the other groups.

Specific examples of the compound represented by the formula (D-1) include, for example, compounds represented by the following formulae (D-1-1) to (D-1-5).

In addition, as the diamine compound for synthesizing polyamidic acid, the compound may be used alone or in combination of two or more kinds.

The diamine compound used to synthesize the polyamidic acid of the present invention preferably contains a diamine (d-1) having a carboxyl group. By using this diamine (d-1), a polyamic acid which has a carboxyl group in a side chain can be synthesized. When the carboxyl group-containing polyamino acid (carboxyl group-containing polymer (A)) and the compound (b) represented by the formula (D-1) are contained in a liquid crystal alignment agent, it is possible to appropriately obtain When the liquid crystal alignment agent is applied on the substrate, the effect is that the region where the film thickness defect occurs in the end portion of the application region can be made narrower.

As long as the diamine (d-1) has at least one carboxyl group and two primary amine groups, the remaining structure is not particularly limited, and aliphatic diamines, alicyclic diamines, aromatic diamines, and diamines can be used. Based organosiloxanes and the like. The diamine (d-1) is preferably an aromatic diamine among these diamines, and particularly preferably has a carboxyl group bonded to an aromatic ring. The number of carboxyl groups in the molecule of the diamine (d-1) is preferably an integer of 1 to 4, and more preferably 1 or 2.

Preferred specific examples of the diamine (d-1) contained in the liquid crystal alignment agent of the present invention include, for example, a compound represented by the following formula (d1-1), a compound represented by the formula (d1-2), and the like.

(In formulas (d1-1) and (d1-2), R ^a is a halogen atom, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and Z ¹ is a single bond, an oxygen atom, or Alkanediyl with 1 to 3 carbons; e and f are each independently an integer of 1 or 2; g and h are each independently an integer of 0 to 2; s and t are each independently s + t = 2 An integer from 0 to 2; where in formula (d1-2), e + g + s ≦ 5 and f + h + t ≦ 5; when g and h are 2, multiple R ^a independently have (Description)

With respect to formula (D1-1) and the formula (D1-2), R ^a is a halogen atom include: fluorine atom, chlorine atom, bromine atom, iodine atom and the like. Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl. These alkyl groups may be linear It can also be branched. Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentoxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, and decyloxy. These alkoxy groups may be linear or branched.

Examples of the alkanediyl group having 1 to 3 carbon atoms in Z ¹ include methylene, ethylene, trimethylene, and propylene.

g and h are preferably 0 or 1, and more preferably 0.

As specific examples of the diamine (d-1), the compound represented by the formula (d1-1) includes, for example, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2, 5-diaminobenzoic acid and the like; Examples of the compound represented by the formula (d1-2) include 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, and 4,4 ' -Diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl- 2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4, 4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl Ethane-3-carboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylether-3-carboxylic acid, and the like.

From the viewpoint of appropriately suppressing poor film thickness at the ends of the application region, the ratio of the diamine (d-1) is preferably set relative to the total amount of the diamine compound used to synthesize the polyamino acid. It is 5 mol% or more, and more preferably 10 mol% or more. In addition, the upper limit value of the ratio of the diamine (d-1) is not particularly limited, and it is preferably set to 90 mol% or less with respect to the total amount of the diamine compound used for synthesis, and more preferably set to 80 Moore% or less. The diamine compound used in synthesizing the polyamidic acid of the present invention preferably contains 30 mol% or more of the aromatic diamine relative to the total diamine compound, more preferably contains 50 mol% or more, and particularly preferably Contains more than 80 mol%.

[Molecular weight regulator]

When synthesizing polyamic acid, a terminal-modified polymer can be synthesized by using an appropriate molecular weight modifier together with the tetracarboxylic dianhydride and diamine compound as described above. By forming the terminal-modified polymer, it is possible to further improve the coatability (printability) of the liquid crystal alignment agent without impairing the effects of the present invention.

Examples of the molecular weight modifier include acid monoanhydrides, monoamine compounds, and monoisocyanates. Cyanate ester compounds and the like. Specific examples of these compounds include, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, and n-tetradecane. Succinic anhydride, n-hexadecyl succinic anhydride, etc. Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octyl Amines, n-dodecylamines, n-octadecylamines, and the like; examples of the monoisocyanate compounds include phenyl isocyanate and naphthyl isocyanate.

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

<Synthesis of Polyamic Acid>

The use ratio of the tetracarboxylic dianhydride and the diamine compound provided by the synthesis reaction of the polyamidic acid of the present invention is preferably 1 equivalent to the amine group of the diamine compound, and the anhydride group of the tetracarboxylic dianhydride becomes 0.2 equivalent ~ The ratio of 2 equivalents is more preferably a ratio of 0.3 to 1.2 equivalents. The synthesis reaction of polyamic acid is preferably performed in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours.

Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol-based solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. As specific examples of these organic solvents, examples of the aprotic polar solvent include N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidone, N-ethyl-2-pyrrolidone, and N , N-dimethylacetamide, N, N-dimethylformamide, dimethylmethylene, γ-butyrolactone, tetramethylurea, hexamethylphosphonium triamine, etc .; phenolic solvents Examples include: phenol, m-cresol, dimethyl Phenol, halogenated phenol, etc .; Examples of the alcohol include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol, propylene glycol, 1,4-butanediol, and triethylene glycol; Examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; examples of the ester include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, Methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, isoamyl propionate, isoamyl isobutyrate, etc .; examples of the ether include : Diethyl ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ether Acetate, Diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, Diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, Diethylene glycol monomethyl ether acetate, Diethylene glycol monoethyl ether Ethyl acetate, tetrahydrofuran, diisoamyl ether, etc. Examples of halogenated hydrocarbons include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, ortho Dichlorobenzene, etc .; hydrocarbons can be listed : Hexane, heptane, octane, benzene, toluene, xylene and the like.

Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenol-based solvent (organic solvent of the first group), or an organic solvent selected from the first group is preferably used. A mixture of one or more of them with one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (organic solvents of the second group). In the latter case, the ratio of the organic solvent in the second group to the total amount of the organic solvent in the first group and the organic solvent in the second group is preferably 50% by weight or less, and more preferably 40% by weight. % Or less, particularly preferably 30% by weight or less. The used amount (α) of the organic solvent is preferably set to 0.1% by weight based on the total amount (α + β) of the reaction solution, and the total amount (β) of tetracarboxylic dianhydride and diamine. ~ 50% by weight.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. The reaction solution can be directly provided to the preparation of the liquid crystal alignment agent, or the polyamino acid contained in the reaction solution can be separated and then provided to the preparation of the liquid crystal alignment agent, or the separated polyamino acid can be purified and then Provided for preparation of liquid crystal alignment agent. In the case where the polyamidic acid is subjected to dehydration and ring closure to prepare polyimide, the reaction solution may be directly provided to the dehydration ring closure reaction, or the polyamidic acid contained in the reaction solution may be separated and then provided. The dehydration ring-closing reaction may be provided, or the isolated polyamidic acid may be purified and then provided to the dehydration ring-closing reaction. Isolation and purification of a polyamic acid can be performed according to a well-known method.

<Polymer (A): Polyurethane>

The polyamidate which is the polymer (A) of the present invention can be obtained, for example, by the following method: [I] using a hydroxyl-containing compound or an ether compound, the polyamino acid obtained by the synthesis reaction is performed A method for synthesis by esterification; [II] A method for reacting a tetracarboxylic acid ester with a diamine compound. Here, the tetracarboxylic acid ester in the method [II] includes an ester compound of a tetracarboxylic acid as a precursor of the tetracarboxylic dianhydride, and examples thereof include a tetracarboxylic acid diester dichloride and a tetracarboxylic acid. Diesters, etc. Examples of the diamine compound usable in the method [II] include the diamine compounds exemplified in the description of the synthesis of the polyamic acid. In addition, the polyamidate may have only a pseudoamidate structure, or may be a partially esterified product in which a pseudoamidate structure and a pseudoamidate structure coexist.

<Polymer (A): Polyimide>

Polyimide, which is the polymer (A) contained in the liquid crystal alignment agent of the present invention, can be obtained by dehydrating and closing the polyamidic acid synthesized in the manner described above, and then performing imidization.

The polyfluorene imine may be a complete fluorinated imide obtained by dehydrating and closing all the fluorinated acid structures of the polyfluorinated acid as a precursor thereof, or may be a fluorinated acid structure and a fluorinated acid ester A part of the structure undergoes dehydration ring closure, and at least any one of the amido acid structure and the amido acid ester structure coexists with a part of the amidine imidate structure. In terms of improving the voltage holding ratio, the polyimide ratio of the polyimide of the present invention is preferably 30% or more, more preferably 40% to 99%, and even more preferably 50% to 99%. The fluorene imine ratio is a total of the fluorene imine ring structure of the polyfluorene imine, the number of fluorene acid ester structures, and the number of fluorene imine ring structures. The fluorene imine ring structure is expressed as a percentage. Proportion of quantity. Here, a part of the fluorene imine ring may be an isofluorene ring.

The dehydration ring closure of the polyamic acid is preferably performed by the following method: heating the polyamic acid; or dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closing catalyst to the solution, Method of heating as needed. Among these methods, the latter method is preferred.

In the method of adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of a polyamic acid to carry out amidation, the dehydrating agent may be an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride. The use amount of the dehydrating agent is preferably set to 0.01 mol to 20 mol with respect to 1 mol of the fluoric acid structure of the polyamic acid. Examples of the dehydration ring-closing catalyst include tertiary amines such as pyridine, trimethylpyridine, dimethylpyridine, and triethylamine. The use amount of the dehydration ring-closing catalyst is preferably 0.01 mol to 10 mol relative to 1 mol of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closing reaction include organic solvents exemplified as those for synthesizing polyamic acid. The reaction temperature of the dehydration ring-closing reaction is preferably 0 ° C to 180 ° C, and more preferably 10 ° C to 150 ° C. The reaction time is preferably 1.0 to 120 hours, and more preferably 2.0 to 30 hours.

In this way, a reaction solution containing polyfluoreneimine was obtained. The reaction solution can be directly provided to the preparation of the liquid crystal alignment agent, or the dehydrating agent and the dehydration ring-closing catalyst can be removed from the reaction solution and then provided to the preparation of the liquid crystal alignment agent, or the polyimide can be separated and then provided to the liquid crystal alignment agent Preparation of the agent, or the isolated polyfluorene imide may be purified and then provided to the preparation of the liquid crystal alignment agent. These purification operations can be performed according to a known method.

<Solution viscosity and weight average molecular weight of polymer (A)>

The polyamidic acid, polyamidate, and polyimide obtained in the manner described above preferably have 10 mPa when they are made into a solution having a concentration of 10% by weight. s ~ 800mPa. The solution viscosity of s is more preferably 15 mPa. s ~ 500mPa. Solution viscosity of s. In addition, the solution viscosity (mPa.s) of the polymer is a concentration of 10% by weight prepared using a good solvent of the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) The value of the polymer solution measured at 25 ° C using an E-type viscometer. In addition, the polyacrylic acid, polyamidate, and polyimide contained in the liquid crystal alignment agent of the present invention are measured in terms of polystyrene by gel permeation chromatography (GPC). The weight average molecular weight (Mw) is preferably 500 to 100,000, and more preferably 1,000 to 50,000.

<Other ingredients>

The liquid crystal alignment agent of this invention may contain other components as needed. Examples of the other component include polymers other than the polymer (A), compounds having at least one epoxy group in the molecule (hereinafter referred to as "epoxy-containing compounds"), functional silane compounds, and the like .

<Other polymers>

The other polymers can be used to improve solution properties or electrical properties. The other poly Examples of the compound include polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, and poly (styrene-phenylcis butylene diimide). Materials, poly (meth) acrylate, etc.

When other polymers are added to the liquid crystal alignment agent, the blending ratio of the other polymers is preferably 50 parts by weight or less with respect to 100 parts by weight of the total of the polymers contained in the liquid crystal alignment agent. It is 0.1 to 40 parts by weight, and particularly preferably 0.1 to 30 parts by weight.

<Epoxy-containing compound>

The epoxy group-containing compound can be used to improve the adhesion or electrical characteristics of the liquid crystal alignment film to the substrate surface. Examples of such epoxy-containing compounds include the following compounds: ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol Diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopenta Glycol diglycidyl ether, N, N, N ', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane , N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidyl-benzylamine, N, N-diglycidyl -Aminomethylcyclohexane, N, N-diglycidyl-cyclohexylamine and the like. Other examples of the epoxy group-containing compound include an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598.

When these epoxy compounds are added to the liquid crystal alignment agent, the blending ratio of the epoxy compound is preferably 40 parts by weight or less with respect to 100 parts by weight of the total polymer contained in the liquid crystal alignment agent. It is preferably 0.1 parts by weight to 30 parts by weight.

<Functional silane compound>

The functional silane compound can be used for the purpose of improving the printability of a liquid crystal alignment agent. Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, and 2-aminopropyl Triethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxy Silane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-triethoxy Silylpropyltriethylene triamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonylacetic acid Ester, 9-trimethoxysilyl-3,6-diazanonanoic acid methyl ester, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethyl Oxysilane, glycidyloxymethyltrimethoxysilane, 2-glycidyloxyethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and the like.

When these functional silane compounds are added to a liquid crystal alignment agent, the blending ratio of the functional silane compound is preferably 2 parts by weight or less with respect to 100 parts by weight of the total polymer contained in the liquid crystal alignment agent. , More preferably 0.02 parts by weight to 0.2 parts by weight.

Further, in addition to the components described above, a compound having at least one oxetanyl group in the molecule, an antioxidant, or the like may be used.

<Solvent>

The liquid crystal alignment agent of the present invention is preferably constituted by dissolving the polymer (A) and other components optionally blended in an organic solvent as required. The solvent used to prepare the liquid crystal alignment agent of the present invention contains: a specific solvent (X), which is 1-butoxy-2-propanol; and a specific solvent (Y), which contains a solvent selected from the group consisting of diethylene glycol diethyl ether, Dipropylene At least one of a group consisting of keto alcohol, propylene glycol diacetate, and dipropylene glycol monomethyl ether.

The specific solvent (X) is 1-butoxy-2-propanol, and the content of the specific solvent (X) is preferably 0.1% to 63% by weight, and more preferably 1% to 60% by weight. %, Particularly preferably 8% to 55% by weight. By setting it as this range, there exists an effect which suppresses generation | occurrence | production of the uneven texture at the time of apply | coating an alignment agent.

The specific solvent (Y) contains at least one selected from the group consisting of diethylene glycol diethyl ether, diacetone alcohol, propylene glycol diacetate, and dipropylene glycol monomethyl ether, and preferably contains at least one selected from the group consisting of diethylene glycol. At least one selected from the group consisting of diethyl ether, propylene glycol diacetate, and dipropylene glycol monomethyl ether, and more preferably at least one selected from the group consisting of diethylene glycol diethyl ether and dipropylene glycol monomethyl ether. One.

The content of the specific solvent (Y) is preferably 0.1% to 63% by weight, more preferably 1% to 60% by weight, and particularly preferably 8% to 55% by weight. By setting it as this range, it is effective in narrowing the width of the film thickness defect (Halo) which arises at the edge part of a coating area at the time of apply | coating an alignment agent.

The solvent used to prepare the liquid crystal alignment agent of the present invention may be a solvent (Z) other than the specific solvent (X) and the specific solvent (Y) for the purpose of improving the coatability of the liquid crystal alignment agent. Examples of the other solvent (Z) include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-pentyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, 1,3-dimethyl-1-imidazolidinone, 3-butoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol , Tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 2- Butene-1,4-diol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,3-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1, 3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5- Hexanediol, 3,4-hexanediol, 2-methyl-2,4-pentanediol, 1,2-heptanediol, 2,3-heptanediol, 3,4-heptanediol, 1 , 3-heptanediol, 2,4-heptanediol, 3,5-heptanediol, 1,4-heptanediol, 2,5-heptanediol, 1,5-heptanediol, 2,6 -Heptanediol, 1,6-heptanediol, 1,7-heptanediol, 2-ethyl-1,3-hexanediol, 1,2-nonanediol, 1,9-nonanediol, 8-methyl-1,8-nonanediol, 1,2-cyclopentanediol, 1,3-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1 , 4-cyclohexanediol, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol Diethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ether acetate, diethylene glycol Dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol Diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propyl carbonate, ethyl acetone, ethyl acetate Ethyl esters, etc. The other solvents (Z) may be used alone or in combination of two or more.

The total amount of the specific solvent (X) and the specific solvent (Y) is preferably 1% to 70% by weight, particularly preferably 5% to 60% by weight, and particularly preferably 10% by weight relative to the total amount of the solvent. ~ 55% by weight. By setting in this range, it is possible to achieve both suppression of uneven texture and narrow halo when the alignment agent is applied.

The content of the specific solvent (X) is preferably 10% to 90% by weight of the total amount of the specific solvent (X) and the specific solvent (Y), more preferably 15% to 85% by weight, and particularly preferably 20 Weight% ~ 80% by weight. By setting in this range, it is possible to achieve both suppression of uneven texture and narrow halo when the alignment agent is applied.

The solid content concentration in the liquid crystal alignment agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) can be appropriately selected in consideration of viscosity, volatility, and the like, and is relatively The range is preferably from 1% by weight to 10% by weight. That is, the liquid crystal alignment agent of the present invention is applied to the surface of a substrate by a method described later, and is preferably heated to form a coating film as a liquid crystal alignment film or a coating film as a liquid crystal alignment film. When it is less than 1% by weight, the film thickness of the coating film becomes too small, and it is difficult 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, and it is difficult to obtain a good liquid crystal alignment film. In addition, the viscosity of the liquid crystal alignment agent increases, and the coating characteristics deteriorate.

A particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal alignment 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% by weight. In the case of using an offset printing method, it is particularly preferable to set the solid content concentration to a range of 3% to 9% by weight, thereby setting the solution viscosity to 12 mPa. s ~ 50mPa. The range of s. In the case of using the inkjet method, it is particularly preferable to set the solid content concentration to a range of 1% to 5% by weight, thereby setting the solution viscosity to 3mPa. s ~ 15mPa. The range of s. The temperature when preparing the liquid crystal alignment agent of the present invention is preferably 10 ° C to 50 ° C, and more preferably 20 ° C to 30 ° C.

<Liquid crystal alignment film and liquid crystal display element>

The liquid crystal alignment film of the present invention is formed using the liquid crystal alignment agent prepared in the manner described above. The liquid crystal display element of the present invention includes a liquid crystal alignment film formed using the liquid crystal registering agent of the present invention. The driving mode of the liquid crystal display element to which the present invention is applied is not particularly limited, and it can be applied to TN type, STN type, IPS type, FFS type, VA Type, Multidomain Vertical Alignment (MVA) type, PSA type and other driving modes.

The liquid crystal display element of the present invention can be manufactured by, for example, the following steps (1) to (3). Step (1) uses different substrates depending on the required driving mode. Steps (2) and (3) are common to each driving mode.

[Step (1): Formation of Coating Film]

First, the liquid crystal alignment agent of the present invention is coated on a substrate, and then the coated surface is heated to form a coating film on the substrate.

(1-1) When manufacturing a TN type, STN type, VA type, MVA type, or PSA type liquid crystal display element, two substrates provided with a patterned transparent conductive film are used as a pair, and each substrate The formation surface of the transparent conductive film is coated with the liquid crystal alignment agent of the present invention. The substrate can be, for example, glass such as float glass, soda glass, or plastics including polyethylene terephthalate, polybutylene terephthalate, polyether, polycarbonate, and poly (alicyclic olefin). Transparent substrate. As the transparent conductive film provided on one surface of the substrate, a Nesa film (registered trademark of the United States PPG Corporation) containing tin oxide (SnO ₂ ), and an indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) can be used. Indium tin oxide (ITO) film and the like. In order to obtain a patterned transparent conductive film, for example, the following methods can be used: a method of forming a pattern by photoetching after forming a patternless transparent conductive film; a method of using a mask having a desired pattern when forming a transparent conductive film Wait.

The method for applying the liquid crystal alignment agent of the present invention is not particularly limited, and it is preferably performed by an offset printing method, a spin coating method, a roll coater method, or an inkjet method. In particular, the liquid crystal alignment agent of the present invention can be used as a coating application by an inkjet method to appropriately obtain a region where a film thickness defect occurs in an end portion of a coating region as much as possible. It is narrowed to achieve a narrow frame effect of the liquid crystal panel. When the liquid crystal alignment agent is applied, in order to improve the adhesion between the substrate surface and the transparent conductive film and the coating film, the surface on which the coating film is formed may be coated with a functional silane compound and a functional titanium compound in advance. And so on.

After the liquid crystal alignment agent is applied, it is preferable to perform preheating (prebaking) for the purpose of preventing sagging of the applied alignment agent. The pre-baking temperature is preferably 30 ° C to 200 ° C, more preferably 40 ° C to 150 ° C, and particularly preferably 40 ° C to 100 ° C. The pre-baking time is preferably 0.25 minutes to 10 minutes, and more preferably 0.5 minutes to 5 minutes. Then, for the purpose of completely removing the solvent, and for the purpose of thermally fluorinating the fluorinated acid structure or fluorinated acid ester structure present in the polymer, if necessary, the calcination (post-baking) is performed. )step. The sintering temperature (post-baking temperature) at this time is preferably 80 ° C to 300 ° C, and more preferably 120 ° C to 250 ° C. The post-baking time is preferably 5 minutes to 200 minutes, and more preferably 10 minutes to 100 minutes. The film thickness of the film formed in this manner is preferably 0.001 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm.

(1-2) In the case of manufacturing an IPS-type or FFS-type liquid crystal display element, the electrode-forming surface of a substrate provided with an electrode (including a transparent conductive film or a metal film patterned into a comb-tooth type) is not provided. The liquid crystal aligning agent of the present invention is coated on one surface of the electrode facing the substrate, and then each coating surface is heated to form a coating film. About the material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and a preferred film of the formed coating film The thickness is the same as that of (1-1). As the metal film, for example, a film containing a metal such as chromium can be used.

In any of the cases (1-1) and (1-2), after the liquid crystal alignment agent is coated on the substrate, the organic solvent is removed to form a coating that forms an alignment film. membrane. At this time, the polymer contained in the liquid crystal alignment agent of the present invention is a polyfluorinated acid, or a polyfluorinated acid ester, or a fluorinated polymer having a fluorinated imine ring structure and a fluorinated acid structure. In this case, a dehydration ring-closing reaction can be performed by further heating after the formation of the coating film to prepare a coating film that is further imidized.

[Step (2): Rubbing treatment]

In the case of manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, a rubbing treatment is performed on the coating film formed in the step (1), and the rubbing treatment is performed by using Rolls of cloths made of rayon, cotton and other fibers are wiped in a certain direction. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film. On the other hand, in the case of manufacturing a VA-type liquid crystal display element, the coating film formed in the step (1) may be directly used as a liquid crystal alignment film, but the coating film may be subjected to a rubbing treatment. In addition, for the liquid crystal alignment film after the rubbing treatment, the following treatment may be further performed to make the liquid crystal alignment film have different liquid crystal alignment ability in each region: by irradiating a part of the liquid crystal alignment film with ultraviolet rays, the A process of changing the pretilt angle of a part of the area; or a process of removing the resist film after forming a resist film on a part of the surface of the liquid crystal alignment film, and then performing a rubbing treatment in a direction different from the previous rubbing treatment. In this case, the visual field characteristics of the obtained liquid crystal display element can be improved.

In the case of manufacturing a PSA type liquid crystal display element, the coating film formed in the step (1) may be directly used to perform the following step (3). However, in order to control the collapse of the liquid crystal molecules, a simple method is used to For the purpose of alignment division, weak friction treatment can also be performed.

[Step (3): Construction of Liquid Crystal Cell]

(3-1) Prepare two substrates on which a liquid crystal alignment film is formed, A liquid crystal cell is produced by disposing liquid crystal between the two substrates placed. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. First, the first method is a conventionally known method. In this method, first, two substrates are arranged to face each other through a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together with a sealant. After liquid crystal is injected into the divided cell gap, the injection hole is sealed, thereby manufacturing a liquid crystal cell. The second method is a method called a One Drop Fill (ODF) method. In this method, a predetermined portion of one of the two substrates on which the liquid crystal alignment film is formed is coated with, for example, a UV-curable sealant, and is further added dropwise to predetermined positions on the liquid crystal alignment film surface. After the liquid crystal, another substrate is bonded to the liquid crystal alignment film so as to face each other. Next, the liquid crystal is spread on the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant, thereby manufacturing a liquid crystal cell. In the case of using any method, it is desirable to remove the liquid crystal cell manufactured in the manner described above, and then heat it to a temperature at which the liquid crystal used obtains an isotropic phase, and then slowly cool it to room temperature to remove it. Flow alignment during liquid crystal filling.

As the sealant, for example, an epoxy resin containing a hardener and alumina balls as a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, a nematic liquid crystal is preferred. For example, a Schiff base liquid crystal and an azo oxide can be used. (azoxy) -based liquid crystal, biphenyl-based liquid crystal, phenylcyclohexane-based liquid crystal, ester-based liquid crystal, terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, Bicyclooctane-based liquid crystal, cubic-based liquid crystal, and the like. In addition, these liquid crystals may be used by adding, for example, cholesteryl chloride, cholesteryl nonanoate, Cholesteric liquid crystals such as cholesteryl carbonate; chiral agents sold under the trade names "C-15" and "CB-15" (manufactured by Merck) ); Ferroelectric liquid crystal (p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate) and the like.

(3-2) In the case of manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as described in (3-1) except that a photopolymerizable compound is injected or dropped simultaneously with the liquid crystal. Then, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films included in the pair of substrates. The voltage applied here can be, for example, 5V to 50V DC or AC. In addition, as the light to be irradiated, for example, ultraviolet rays and visible rays including light having a wavelength of 150 nm to 800 nm can be used, and ultraviolet rays including light having a wavelength of 300 nm to 400 nm are preferably used. As a light source for irradiating light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, and the like can be used. In addition, the ultraviolet rays in the preferable wavelength region can be obtained by a method in which a light source is used in combination with, for example, a filter, a diffraction grating, and the like. The light irradiation amount is preferably 1,000 J / m ² or more and less than 200,000 J / m ² , and more preferably 1,000 J / m ² to 100,000 J / m ² .

Next, a liquid crystal display element of the present invention can be obtained by laminating a polarizing plate on 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 an “H film” with a protective cellulose acetate film or a polarizing plate including the H film itself. The "H film" is made by absorbing iodine while extending the orientation of polyvinyl alcohol. In addition, when the coating film is subjected to a rubbing treatment, the two substrates form a predetermined angle with each other in the rubbing direction in each coating film, for example, they become positive. Orthogonal or anti-parallel configuration.

The liquid crystal display element of the present invention can be effectively applied to a variety of devices, such as: clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (Personal Digital Assistant (PDA), digital cameras, mobile phones, smartphones, various monitors, LCD TVs and other display devices.

[Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these examples.

In the following examples and comparative examples, the following methods were used to measure the polyimide imidization ratio of the polymer solution, the solution viscosity of the polymer solution, the weight average molecular weight of the polymer, and the epoxy equivalent.

[Perylene imidation rate of polyimide]

A solution of polyfluoreneimide was poured into pure water, and the resulting precipitate was sufficiently dried under reduced pressure at room temperature, and then dissolved in deuterated dimethylsulfine. Tetramethylsilane was used as a reference substance at room temperature. ¹ H-Nuclear Magnetic Resonance (NMR) was measured. Based on the obtained ¹ H-NMR spectrum, the fluorene imidization ratio [%] was determined by the following formula (x).

醯 Imidation rate [%] = (1-A ¹ / A ² × α) × 100 ... (x)

(In formula (x), A ¹ is the peak area of NH-derived protons occurring near the chemical shift of 10 ppm, A ² is the peak area of other protons, and α is the precursor of other protons relative to the polymer. (Number ratio of one proton of NH group in (Polyamic acid))

[Solution viscosity of polymer solution]

Solution viscosity of polymer solution [mPa. s] is a solution prepared by using a predetermined solvent to a polymer concentration of 10% by weight, and measured at 25 ° C using an E-type viscometer.

[Polymer average molecular weight]

The weight average molecular weight is a polystyrene conversion value measured by gel permeation chromatography under the following conditions.

Column: Made by Tosoh, TSKgelGRCXLII

Solvent: Tetrahydrofuran

Temperature: 40 ° C

Pressure: 68kgf / cm ²

[Epoxy equivalent]

The epoxy equivalent is measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.

<Synthesis of Polymer (A)> [Synthesis Example 1: Synthesis of Polyfluorene (PI-1)]

As a tetracarboxylic dianhydride, 22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic dianhydride (TCA) as a diamine, and p-benzene as a diamine 8.6 g (0.08 moles) of p-phenylene diamine (PDA) and 10.5 g (0.02 moles) of cholestanyl 3,5-diaminobenzoate (HCDA), Dissolved in 166 g of N-methyl-2-pyrrolidone (NMP) at 60 ° C The reaction was performed for 6 hours to obtain a solution containing 20% by weight of polyamic acid. The obtained polyamic acid solution was divided into a small amount, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by weight, and the viscosity of the solution was 90 mPa. s.

Next, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7% by weight, 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a dehydration ring-closure reaction was performed at 110 ° C for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with a new NMP (by this operation, the pyridine and acetic anhydride used in the dehydration ring-closing reaction are removed from the system; the same applies hereinafter), thereby obtaining a A solution of polyfluorene imine (PI-1) with a hydrazone imidization rate of about 68%. A small amount of the obtained polyimide solution was added, and NMP was added to prepare a solution having a polyimide concentration of 10% by weight. The measured solution viscosity was 45 mPa. s.

[Synthesis Example 2: Synthesis of polyimide (PI-2)]

22.5 g (0.1 mole) of TCA as tetracarboxylic dianhydride, 6.1 g (0.04 mole) of 3,5-diamino benzoic acid (35DAB) as diamine, and bile 5.0 g (0.010 moles) of cholestanyloxy-2,4-diaminobenzene (HCODA) and the compound (LDA) of the formula (D-1-5) 9.3 g (0.020 mole), 4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine (4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine, APPC) 9.4 g (0.030 mol), dissolved in 210 g of NMP, and reacted at 60 ° C. for 6 hours to obtain a solution containing 20% by weight of polyamic acid. The obtained polyamic acid solution was divided into a small amount, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by weight, and the viscosity of the solution was 76 mPa. s.

Next, NMP was added to the obtained polyamic acid solution to prepare polyamine. A solution having an acid concentration of 7% by weight was added with 11.9 g of pyridine and 15.4 g of acetic anhydride, and the dehydration ring-closure reaction was performed at 110 ° C for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with a new NMP, thereby obtaining a solution containing 25% by weight of polyimide (PI-2) having a imidization rate of about 80%. A small amount of the obtained polyimide solution was added, and NMP was added to prepare a solution having a polyimide concentration of 10% by weight. The measured solution viscosity was 39 mPa. s.

[Synthesis Example 3: Synthesis of Polyimide (PI-3)]

2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride (2,4,6,8-tetracarboxy bicyclo [3.3] .0] octane-2: 4,6: 8-dianhydride (BODA) 18.7 g (0.075 mole) and 1,2,3,4-cyclobutane tetracarboxylic dianhydride (1,2,3,4- cyclobutane tetracarboxylic dianhydride (CB) 4.90 g (0.025 mole), 35DAB as diamine 10.7 g (0.07 mole) and 1,3-diamino-4- {4- [trans-4- (trans- 4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene (1,3-diamino-4- {4- [trans-4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene, PBCH5DAB, 13.1 g (0.03 mole) of the compound represented by the formula (D-1-2), dissolved in 190 g of NMP, and reacted at 60 ° C. for 6 hours to obtain a solution containing 20% by weight of polyamic acid . A small amount of the obtained polyamic acid solution was added, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by weight, and the viscosity of the solution obtained was 85 mPa. s.

Next, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7% by weight, 9.5 g of pyridine and 12.3 g of acetic anhydride were added, and a dehydration ring-closure reaction was performed at 110 ° C for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain 26% by weight of hydrazone. Polyimide (PI-3) solution with an imidization ratio of about 65%. A small amount of the obtained polyimide solution was added, and NMP was added to prepare a solution having a polyimide concentration of 10% by weight. The measured solution viscosity was 45 mPa. s.

[Synthesis Example 4: Synthesis of polyimide (PI-4)]

110 g (0.50 mole) of TCA as tetracarboxylic dianhydride and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo- 3-furanyl) naphtho [1,2-c] furan-1,3-dione 160 g (0.50 mole), 91 g (0.85 mole) of p-phenylenediamine (PDA) as diamine, 1,3 -25 g (0.10 mole) of bis (3-aminopropyl) tetramethyldisilazane and 25 g (0.040 mole) of 3,6-bis (4-aminobenzyloxy) cholestane 1.4 g (0.015 mol) of aniline as a monoamine was dissolved in 960 g of NMP and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was added, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by weight, and the viscosity of the solution was 60 mPa. s.

Next, 2,700 g of NMP was added to the obtained polyamic acid solution, 390 g of pyridine and 410 g of acetic anhydride were added, and a dehydration ring-closure reaction was performed at 110 ° C for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with a new γ-butyrolactone, thereby obtaining a polyimide (PI-4) containing 15% by weight of fluorene imine (PI-4). The solution is approximately 2,500 g. This solution was divided into a small amount, and NMP was added to prepare a solution having a polyimide concentration of 10% by weight. The measured solution viscosity was 70 mPa. s.

[Synthesis Example 5: Synthesis of polyimide (PI-5)]

22.4 g (0.1 mole) of TCA as tetracarboxylic dianhydride, 8.6 g (0.08 mole) of PDA as diamine, 2.0 g (0.01 mole) of 4,4'-diaminodiphenylmethane, and 3.2g (0.01 mole) of 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, dissolved in NMP In 324 g, a reaction was performed at 60 ° C. for 4 hours to obtain a solution containing 10% by weight of polyamic acid.

Then, 360 g of NMP was added to the obtained polyamic acid solution, 39.5 g of pyridine and 30.6 g of acetic anhydride were added, and a dehydration ring-closure reaction was performed at 110 ° C for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with a new NMP to obtain a solution containing 10% by weight of polyimide (PI-5) having a fluorinated imidization rate of about 93%. The obtained polyfluorene imine solution was divided into a small amount, and the viscosity of the solution obtained was 30 mPa. s.

[Synthesis Example 6: Synthesis of polyfluorene (PI-6)]

A polyamic acid solution was obtained by the same method as in Synthesis Example 1 except that the diamine used was changed to 35DAB 12.2 g (0.08 mole) and HCODA 9.8 g (0.02 mole). A small amount of the obtained polyamic acid solution was added, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by weight. The measured solution viscosity was 80 mPa. s.

Next, fluorene imidization was performed by the same method as in Synthesis Example 1, and a solution containing 26% by weight of polyfluorene imine (PI-6) with a fluorene imidization rate of about 65% was obtained. A small amount of the obtained polyimide solution was added, and NMP was added to prepare a solution having a polyimide concentration of 10% by weight. The measured solution viscosity was 40 mPa. s.

[Synthesis Example 7: Synthesis of Polyamidic Acid (PA-1)]

200 g (1.0 mol) of CB as tetracarboxylic dianhydride and 210 g (1.0 mol) of 2,2'-dimethyl-4,4'-diaminobiphenyl as diamine were dissolved in 370 g of NMP And in a mixed solvent of 3,300 g of γ-butyrolactone, a reaction was carried out at 40 ° C. for 3 hours to obtain a solution containing 10% by weight of polyamic acid (PA-1). The obtained polyamic acid solution was divided into a small amount, and the viscosity of the solution obtained was 160 mPa. s.

[Synthesis Example 8: Synthesis of polyamidic acid (PA-2)]

In addition to the tetracarboxylic dianhydride used was 196 g (0.9 mol) of pyromelite dianhydride (PMDA) and 19.6 g (0.1 mol) of CB, and the diamine was set to PDA 0.2 mol and 4, Except for 4'-diaminodiphenylether (DDE), the same method as in Synthesis Example 7 was used to obtain 10% by weight of polyphosphonic acid (PA-2). Solution. The obtained polyamic acid solution was divided into a small amount, and the viscosity of the solution obtained was 170 mPa. s.

[Synthesis Example 9: Synthesis of Polyamic Acid (PA-3)]

The tetracarboxylic dianhydride used was 424 g (1.0 mol) of TMPG (TMPG below) and 348 g (1.0 g of 1,4-BAAB below) diamine. Except for Mohr), a solution containing 10% by weight of polyamic acid (PA-3) was obtained by the same method as in Synthesis Example 7. The obtained polyamic acid solution was divided into a small amount, and the viscosity of the solution obtained was 150 mPa. s.

[Chemical 5]

[Synthesis Example 10: Synthesis of polyorganosiloxane (APS-1)]

In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux cooling tube, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (2- (3,4-epoxycyclohexyl) ethyl trimethoxy) was added. 100.0 g of silane (ECETS), 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine were mixed at room temperature. Then, 100 g of deionized water was added dropwise from the dropping funnel for 30 minutes, and then the reaction was performed at 80 ° C. for 6 hours while stirring under reflux. After the reaction, the organic layer was taken out and washed with a 0.2% by weight ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain reactivity as a thick transparent liquid. Polyorganosiloxane (APS-1). As a result of ¹ H-NMR analysis of this reactive polyorganosiloxane, a chemical shift (δ) = 3.2 ppm was obtained, and a peak based on epoxy groups was obtained as a theoretical intensity. It was confirmed that no epoxy group was generated during the reaction. side effects. The weight average molecular weight Mw of the obtained reactive polyorganosiloxane was 3,500, and the epoxy equivalent was 180 g / mole.

Next, in a 200 mL three-necked flask, 10.0 g of reactive polyorganosiloxane (APS-1), 30.28 g of methyl isobutyl ketone as a solvent, and 4-dodecyloxybenzene as a reactive compound were added. 3.98 g of formic acid and 0.10 g of UCAT 18X (trade name, manufactured by San-Apro) were used as a catalyst, and a reaction was performed at 100 ° C. for 48 hours while stirring. After the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed three times with water, and the organic layer was dried with magnesium sulfate. After drying, the solvent was distilled off to obtain 9.0 g of a liquid crystal-aligned polyorganosiloxane (APS-1). The weight average molecular weight Mw of the obtained polymer was 9,900.

<Preparation of liquid crystal alignment agent (1)> [Example 1]

Polyimide (PI-1) was used as the polymer (A), and 1-butoxy-2-propanol (BP) and diacetone alcohol (DAA) were added thereto. ) And N-methyl-2-pyrrolidone (NMP) as solvents, and a solution having a solvent composition of BP: DAA: NMP = 45: 5: 50 (weight ratio) and a solid content concentration of 3.5% by weight was prepared. This solution was filtered using a sieve with a pore size of 1 μm to prepare a liquid crystal alignment agent (S-1). In addition, the liquid crystal alignment agent (S-1) is mainly used for manufacturing a liquid crystal display element of a vertical alignment type.

[Inkjet applicability evaluation]

The prepared liquid crystal alignment agent (S-1) was coated on a silicon wafer using an inkjet coating apparatus (manufactured by Shibaura Mechatronics (KK)). The coating conditions were set to 64 heads and 0.2 g per head. Two rounds of coating (4 coatings) were performed in seconds. Then, the solvent was removed by heating (pre-baking) on a hot plate at 80 ° C. for 1 minute to form a coating film having an average film thickness of 80 nm.

The coating film formed on the silicon wafer was observed visually, and the case where uneven texture was not observed was evaluated as ○, the case where slight texture unevenness was observed was evaluated as △, and the uneven texture was observed in the plane. Was evaluated as ×.

The coating film formed on the silicon wafer was observed visually, and the width of the portion where the film thickness was thinner than the central portion at the end of the coating film and the color tone changed (portion with poor film thickness) was measured. To perform halo evaluation. The halo evaluation was performed in such a manner that the width of the portion where the hue changed at the end of the coating film was 2.9 mm The following cases were evaluated as ○, the cases where the width was more than 3.0 mm and 3.9 mm or less were evaluated as △, and the cases where the width was more than 4.0 mm were evaluated as ×. The results are shown in Table 1-1 below.

<Example 2 to Example 8, Comparative Example 1 to Comparative Example 5>

A liquid crystal alignment agent (S-2) was prepared in the same manner as in Example 1 except that the types and amounts of the polymer (A), other components, and solvent used were changed to those described in Table 1-1 below. Liquid crystal alignment agent (S-13). In addition, using the prepared liquid crystal alignment agents, a coating film was formed on the substrate in the same manner as in Example 1, and the inkjet coating properties were evaluated. The results are shown in Table 1-1.

<Example 9, Comparative Example 6 to Comparative Example 7>

A liquid crystal alignment agent (S-14) was prepared in the same manner as in Example 1 except that the types and amounts of the polymer (A), other components, and solvents used were changed to those described in Table 1-2 below. Liquid crystal alignment agent (S-16).

[Evaluation of print coatability]

The prepared liquid crystal alignment agent was evaluated for printability to a substrate. Evaluation was performed as follows. First, for the prepared liquid crystal alignment agent (S-14), a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd., Angstromer model "S40L-532") was used. Under the condition that the amount of the liquid crystal alignment agent added to the anilox roll is 20 drops (about 0.2 g), the anilox roll is brought into contact with the printing plate, and the operation (hereinafter referred to as idling) is performed a total of 10 times.

After 10 idle cycles, continue to use silicon wafers for official printing. In the official printing, after idling, 10 substrates are put in at intervals of 60 seconds. Each substrate coated with the liquid crystal alignment agent is heated (pre-baked) at 80 ° C for 1 minute to remove the solvent, and then at 210 ° C. Under heating (post-baking) for 10 minutes, a coating with a film thickness of about 80 nm is formed. membrane. This coating film was observed with a microscope with a magnification of 20 times to evaluate printability.

The evaluation was performed using a silicon wafer that was officially printed for the 10th time after idling. The coating film formed on the silicon wafer was observed visually, and the case where uneven texture was not observed was evaluated as ○, the case where slight texture unevenness was observed was evaluated as △, and the uneven texture was observed in the plane. Was evaluated as ×.

The coating film formed on the silicon wafer was observed visually, and the width of the portion where the film thickness was thinner than the central portion at the end of the coating film and the color tone changed (portion with poor film thickness) was measured. To perform halo evaluation. The halo evaluation is performed as follows: the width of the portion where the color tone changes in the end of the coating film is 1.4 mm or less, the case of the width greater than 1.5 mm and 1.9 mm or less is evaluated as △, and the width is greater than The case of 2.0 mm was evaluated as x. The results are shown in Table 1-2.

Table 1-2 shows the results of evaluating the print coatability of the liquid crystal alignment agent (S-15) and the liquid crystal alignment agent (S-16) in the same manner.

In Table 1, the abbreviations of the solvents have the following meanings.

[Other ingredients]

3-AMP: 3-aminomethylpyridine

[Specific solvent (X)]

BP: 1-butoxy-2-propanol

[Specific solvent (Y)]

DAA: Diacetone alcohol

DEDG: Diethylene glycol diethyl ether

PGDAc: propylene glycol diacetate

DPM: Dipropylene glycol monomethyl ether

[Other solvents]

NMP: N-methyl-2-pyrrolidone

GBL: γ-butyrolactone

Claims (6)

A liquid crystal alignment agent comprising at least one polymer (A) selected from the group consisting of polyamidic acid, polyamidate, and polyimide, and a solvent, and the liquid crystal alignment agent includes: The solvent contains: a specific solvent (X), which is 1-butoxy-2-propanol; and a specific solvent (Y), which is selected from the group consisting of diethylene glycol diethyl ether, diacetone alcohol, and propylene glycol diacetic acid. The total amount of the specific solvent (X) and the specific solvent (Y) of at least one of the group consisting of the ester is 1% to 70% by weight based on the total amount of the solvent. The liquid crystal alignment agent according to item 1 of the scope of patent application, wherein the content of the specific solvent (X) is 10% to 90% by weight of the total amount of the specific solvent (X) and the specific solvent (Y). The liquid crystal alignment agent according to item 1 of the scope of patent application is for coating by an inkjet method. The liquid crystal alignment agent according to item 1 of the scope of patent application, wherein the polymer (A) is a polymer obtained by a reaction of a tetracarboxylic dianhydride and a diamine compound, and the liquid crystal alignment agent includes: Selected from 2,3,5-tricarboxycyclopentylacetic dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 1,2 At least one of the group consisting of 3,4-cyclobutanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, and cyclopentanetetracarboxylic dianhydride is used as the tetracarboxylic dianhydride. A liquid crystal alignment film is formed using the liquid crystal alignment agent according to any one of claims 1 to 4 in the scope of patent application. A liquid crystal display element includes the liquid crystal alignment film according to item 5 of the patent application scope.