JP6248784B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element, and more specifically, includes a liquid crystal aligning agent for realizing a narrow frame, a liquid crystal aligning film produced using the liquid crystal aligning agent, and the same. The present invention relates to a liquid crystal display element.

  Conventionally, as a liquid crystal display element, various drive systems having different electrode structures, physical properties of liquid crystal molecules to be used, manufacturing processes, and the like have been developed. For example, TN type, STN type, VA type, in-plane switching type (IPS type) ), Various liquid crystal display elements such as FFS type and PSA type are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polyamic acid or polyimide is generally used from the viewpoints of various properties such as heat resistance, mechanical strength, and affinity with liquid crystal.

  In the liquid crystal aligning agent, polymer components such as polyamic acid and polyimide are dissolved in a solvent, and the liquid crystal aligning film is formed by applying the liquid crystal aligning agent to a substrate and heating. As a method for applying a liquid crystal aligning agent to a substrate, conventionally, a method using an offset printing apparatus has been generally used, but there is a demerit that uneven coating tends to occur with the recent increase in size of a liquid crystal panel. It was. Therefore, in order to solve such a problem, in recent years, a coating method by an ink jet method has been introduced in a manufacturing process of a large liquid crystal panel. Along with this, various liquid crystal aligning agents have been proposed for application to coating by the ink jet method (see, for example, Patent Document 1 and Patent Document 2).

JP 2008-10899 A JP 2009-300465 A

  According to the application by the ink jet method, it is possible to reduce application unevenness of the liquid crystal aligning agent in the production of a large liquid crystal panel, but at the end of the application region, the film is caused by dripping or insufficient application amount. There is a demerit that the thickness tends to be thin. Since such a film thickness defect causes display unevenness of the liquid crystal panel, the quality of the display area has been ensured so far by designing the panel frame widely in large liquid crystal panels. However, in recent years, there has been a demand for narrowing the frame with the aim of further improving the quality of liquid crystal panels, and further improvements have been demanded for liquid crystal aligning agents in order to achieve this.

  This invention is made | formed in view of the said subject, and makes it a main objective to provide the liquid crystal aligning agent which can suppress the film thickness defect in the edge part of an application | coating area | region.

  As a result of intensive studies to achieve the above-described problems of the prior art, the present inventors can solve the above-mentioned problems by adding a specific compound as a part of the solvent component of the liquid crystal aligning agent. As a result, the present invention has been completed. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element.

  In one aspect, the present invention contains at least one polymer (A) selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide and a solvent, and the solvent is 1-butoxy-2-propanol. Provided is a liquid crystal aligning agent containing a specific solvent (X) and a specific solvent (Y) containing at least one selected from the group consisting of diethylene glycol diethyl ether, diacetone alcohol, propylene glycol diacetate, and dipropylene glycol monomethyl ether.

  In another aspect, the present invention provides 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 aligning agent of the present invention, by including the specific solvent (X) and the specific solvent (Y) in the liquid crystal aligning agent, the region where the film thickness defect occurs at the end of the coating region can be made as narrow as possible. it can. In addition, since the liquid crystal display element of the present invention has a liquid crystal alignment film formed using the liquid crystal aligning agent of the present invention, display unevenness due to film thickness defects hardly occurs at the end of the liquid crystal alignment film, and a narrow frame Can be achieved. Thereby, it is possible to secure 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 made as small as possible.

The liquid crystal aligning agent of this invention contains the at least 1 sort (s) of polymer (A) chosen from the group which consists of a polyamic acid, polyamic acid ester, and a polyimide, a specific solvent (X), and a specific solvent (Y). Below, each component contained in the liquid crystal aligning agent of this invention and the other component arbitrarily mix | blended as needed are demonstrated.
<Polymer (A): Polyamic acid>
The polyamic acid as the polymer (A) in the present invention can be obtained by reacting a tetracarboxylic dianhydride and a diamine compound.
[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride and the like. Can be mentioned. Specific examples of these are:
Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- No 1,2-dicarboxylic acid 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 4,6: 8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride Cyclopentanetetracarboxylic dianhydride and the like;
Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and the like; respectively, and tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  The tetracarboxylic dianhydride used for the synthesis preferably contains an alicyclic tetracarboxylic dianhydride from the viewpoint of transparency and solubility in a solvent. Among alicyclic tetracarboxylic dianhydrides, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5 -Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5 -Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: Includes at least one selected from the group consisting of 8-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, and cyclopentanetetracarboxylic dianhydride thing 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 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 selected from the group consisting of cyclopentanetetracarboxylic dianhydride (hereinafter referred to as a specific tetracarboxylic dianhydride). It is more preferable that it also contains an anhydride.

When the above-mentioned specific tetracarboxylic dianhydride is included as the tetracarboxylic dianhydride used in the synthesis, the total content of the specific tetracarboxylic dianhydride is the tetracarboxylic dianhydride used in the synthesis of polyamic acid. It is preferably 10 mol% or more, more preferably 20 to 100 mol%, still more preferably 50 to 100 mol%, based on the total amount of the product.
[Diamine compound]
Examples of the diamine compound used for synthesizing the polyamic acid in the present invention include aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane and the like. Specific examples of these diamine compounds include aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;
Examples of aromatic diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 2,7-diaminofluorene, 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) hexafluoropropane 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylene Riden) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diamino Pyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N , N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-5-amine, 1- (4-aminophen 2) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, 3,5-diaminobenzoic acid, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3, 5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, 3,5-diamino Lanostanyl benzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5- Diaminobenzoate, 4- (4′-trifluoromethylbenzoyloxy) cyclohexyl-3,5-di Aminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, , 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-diaminobenzoyloxy) cholestane, 3,6-bis (4-aminobenzoyloxy) cholestane and the following formula (D-1)

(In 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 a carbon number. 1 to 3 alkanediyl groups, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and n is 0 or 1, provided that a and b is never 0 at the same time.)
A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, and the like, and diamines described in JP 2010-97188 A can be used.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _n —” in the formula (D-1) include an alkanediyl group having 1 to 3 carbon atoms, * —O—, * —COO— or * —O—C ₂ H ₄ —O— (however, a bond marked with “*” is bonded to a diaminophenyl group) is preferred.

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

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

  In addition, the diamine compound used for the synthesis | combination of a polyamic acid can use the said thing individually by 1 type or in combination of 2 or more types.

  Moreover, it is preferable that the diamine compound used for the synthesis | combination of the polyamic acid in this invention contains the diamine (d-1) which has a carboxyl group. By using the diamine (d-1), a polyamic acid having a carboxyl group in the side chain can be synthesized. By incorporating such a carboxyl group-containing polyamic acid (carboxyl group-containing polymer (A)) into the liquid crystal aligning agent together with the compound (b) represented by the above formula (1), a liquid crystal aligning agent is obtained. When applied to the substrate, it is possible to suitably obtain an effect that the region where the film thickness defect occurs at the end of the applied region can be made narrower.

  The diamine (d-1) is not particularly limited as long as it has at least one carboxyl group and two primary amino groups, and is not limited to aliphatic diamine, alicyclic diamine, aromatic diamine, diamino. Organosiloxane and the like can be used. Among these, the diamine (d-1) is preferably an aromatic diamine, and particularly preferably a carboxyl group is bonded to the aromatic ring. Further, the number of carboxyl groups in the diamine (d-1) molecule is preferably an integer of 1 to 4, and more preferably 1 or 2.

  Preferable specific examples of the diamine (d-1) contained in the liquid crystal aligning 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. Can be mentioned.

(In formula (d1-1) and formula (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 an alkanediyl group having 1 to 3 carbon atoms, 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 Each independently represents an integer of 0 to 2 satisfying s + t = 2, provided that in formula (d1-2), e + g + s ≦ 5 and f + h + t ≦ 5, and when g and h are 2, a plurality of R ^a independently has the above definition.)
In formula (d1-1) and formula (d1-2), examples of the halogen atom in R ^a include a fluorine atom, a chlorine atom, a bromine atom, and a fluorine atom. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group. It may be linear or branched. Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, and decyloxy group. These may be linear or branched.

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

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

  Specific examples of the diamine (d-1) include compounds represented by the above formula (d1-1) such as 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, and 2,5-diaminobenzoic acid. As the compound represented by the above formula (d1-2), for example, 4,4′-diaminobiphenyl-3,3′-dicarboxylic acid, 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'-diamy Diphenylethane-3-carboxylic acid, 4,4'-diaminodiphenyl ether 3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3-carboxylic acid and the like; may be mentioned, respectively.

The ratio of the diamine (d-1) is 5 mol% or more based on the total amount of the diamine compound used for the synthesis of the polyamic acid, from the viewpoint of suitably suppressing the film thickness failure at the end of the coating region. Is preferable, and it is more preferable to set it as 10 mol% or more. Moreover, although the upper limit of the ratio of diamine (d-1) is not specifically limited, It is preferable to set it as 90 mol% or less with respect to the whole quantity of the diamine compound used for a synthesis | combination, and to set it as 80 mol% or less. preferable. The diamine compound used when synthesizing the polyamic acid in the present invention preferably contains an aromatic diamine in an amount of 30 mol% or more, more preferably 50 mol% or more, based on the total diamine compound, and more preferably 80 mol%. It is more preferable to include the above.
[Molecular weight regulator]
When synthesizing a polyamic acid, a terminal-modified polymer may be synthesized using an appropriate molecular weight regulator together with the tetracarboxylic dianhydride and diamine compound as described above. By using such a terminal-modified polymer, the coating property (printability) of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention.

  Examples of molecular weight regulators include acid monoanhydrides, monoamine compounds, monoisocyanate compounds, and the like. Specific examples thereof include acid monoanhydrides such as maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic. Acid anhydrides, n-hexadecyl succinic anhydride, etc .; monoamine compounds such as aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, Examples of the monoisocyanate compound include n-dodecylamine and n-octadecylamine; for example, phenyl isocyanate and naphthyl isocyanate;

The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine used.
<Synthesis of polyamic acid>
The ratio of the tetracarboxylic dianhydride and the diamine compound used in the polyamic acid synthesis reaction in the present invention is such that the acid anhydride group of the tetracarboxylic dianhydride is equivalent to 1 equivalent of the amino group of the diamine compound. A ratio of 0.2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable. 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., more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

Here, examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like. Specific examples of these organic solvents include aprotic polar solvents such as N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, N, N- Dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide and the like; phenolic solvents such as phenol, m-cresol, xylenol and halogenated phenol;
Examples of the alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and the like; examples of the ketone include acetone, methyl ethyl ketone, Methyl isobutyl ketone, cyclohexanone, etc .; as esters, for example, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, Isoamyl propionate, isoamyl isobutyrate and the like;
Examples of ethers include diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, and ethylene glycol ethyl ether acetate. Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, diisopentyl ether and the like;
Examples of the halogenated hydrocarbon include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, and the like. Examples of the hydrocarbon include hexane, heptane, octane, benzene, Toluene, xylene, etc. can be mentioned respectively.

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

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction. Isolation and purification of the polyamic acid can be performed according to known methods.
<Polymer (A): Polyamic acid ester>
The polyamic acid ester as the polymer (A) in the present invention is, for example, [I] a method of synthesizing the polyamic acid obtained by the above synthesis reaction by esterification using a hydroxyl group-containing compound or an ether compound, [ II] A method of reacting a tetracarboxylic acid ester with a diamine compound. Here, examples of the tetracarboxylic acid ester in the method [II] include an ester compound of a tetracarboxylic acid which is a precursor of the tetracarboxylic dianhydride, and examples thereof include tetracarboxylic acid diester dichloride and tetracarboxylic acid diester. Can be mentioned. Moreover, as a diamine compound which can be used in method [II], the diamine compound illustrated by the description of the synthesis | combination of the said polyamic acid can be mentioned. The polyamic acid ester 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.
<Polymer (A): Polyimide>
The polyimide as the polymer (A) contained in the liquid crystal aligning agent of the present invention can be obtained by dehydrating and ring-closing and imidizing the polyamic acid synthesized as described above.

  The polyimide may be a completely imidized product obtained by dehydrating and ring-closing all of the amic acid structure of the polyamic acid that is a precursor thereof, and a part of the amic acid structure and the amic acid ester structure may be dehydrating and ring-closing. Moreover, it may be a partially imidized product in which at least one of an amic acid structure and an amic acid ester structure and an imide ring structure coexist. The polyimide in the present invention is preferably 30% or more, more preferably 40 to 99%, and still more preferably 50 to 99% in that the voltage holding ratio can be increased. . This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of amic acid structures of polyimide, the number of amic acid ester structures, and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

  The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. . Of these, the latter method is preferred.

  In the method of imidizing a polyamic acid solution by adding a dehydrating agent and a dehydrating ring-closing catalyst, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, or after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, it may be used for the preparation of the liquid crystal aligning agent. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods.
<Solution viscosity and weight average molecular weight of polymer (A)>
The polyamic acid, polyamic acid ester and polyimide obtained as described above preferably have a solution viscosity of 10 to 800 mPa · s, when this is made into a solution having a concentration of 10% by weight, and 15 to 500 mPa · s. More preferably, it has a solution viscosity of s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer. Moreover, about the polyamic acid, polyamic acid ester, and polyimide which are contained in the liquid crystal aligning agent of this invention, the weight average molecular weight (Mw) of polystyrene conversion measured by gel permeation chromatography (GPC) is 500-100,000. It is preferable that it is 1,000-50,000.
<Other ingredients>
The liquid crystal aligning agent of this invention may contain the other component as needed. Examples of such other components include other polymers other than the polymer (A), compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy group-containing compound”), and functional silane compounds. Etc.
<Other polymers>
The above other polymers can be used for improving solution properties and electrical properties. Examples of such other polymers include polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate, and the like.

When adding another polymer to a liquid crystal aligning agent, it is preferable that the mixture ratio is 50 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent. The amount is more preferably 40 parts by weight, and still more preferably 0.1 to 30 parts by weight.
<Epoxy group-containing compound>
The epoxy group-containing compound can be used to improve the adhesion and electrical properties with the substrate surface in the liquid crystal alignment film. Examples of such epoxy group-containing compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylylene diene Amine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diamy Diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. In addition, as an example of the epoxy group-containing compound, an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can be used.

When these epoxy compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 40 parts by weight or less, and 0.1 to 30 parts by weight with respect to a total of 100 parts by weight of the polymer contained in the liquid crystal aligning agent. More preferred.
<Functional silane compound>
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane.

  When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less, based on the total of 100 parts by weight of the polymer contained in the liquid crystal aligning agent, 2 parts by weight is more preferred.

As other components, in addition to the above, a compound having at least one oxetanyl group in the molecule, an antioxidant, or the like can be used.
<Solvent>
The liquid crystal aligning agent of the present invention is constituted by dissolving the polymer (A) and other components optionally blended as necessary, preferably in an organic solvent. The solvent used for the preparation of the liquid crystal aligning agent of the present invention is a specific solvent (X) which is 1-butoxy-2-propanol, diethylene glycol diethyl ether, diacetone alcohol, propylene glycol diacetate, dipropylene glycol monomethyl ether A specific solvent (Y) containing at least one selected from the group consisting of:

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 of the total amount of the solvent, and 1 to 60% by weight. It is more preferable that it is 8 to 55% by weight. By setting it in this range, there is an effect of suppressing the generation of streak unevenness when the alignment agent is applied.
The specific solvent (Y) includes at least one selected from the group consisting of diethylene glycol diethyl ether, diacetone alcohol, propylene glycol diacetate, dipropylene glycol monomethyl ether, and from diethylene glycol diethyl ether, propylene glycol diacetate, dipropylene glycol monomethyl ether It is preferable to include at least one selected from the group consisting of, and more preferable to include at least one selected from the group consisting of diethylene glycol diethyl ether and dipropylene glycol monomethyl ether.
The content of the specific solvent (Y) is preferably 0.1 to 63% by weight of the total amount of the solvent, more preferably 1 to 60% by weight, and 8 to 55% by weight. Particularly preferred. By setting it in this range, there is an effect of narrowing the width of the film thickness defect (Halo) generated at the end of the application region when the alignment agent is applied.

  As a solvent used for preparation of the liquid crystal aligning agent of this invention, in order to improve the applicability | paintability of a liquid crystal aligning agent, other solvents (Z) other than the said specific solvent (X) and a specific solvent (Y) are used. Also good. 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-hexane Diol, 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 ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl Ether, ethi Glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate , Isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, acetylacetone, ethyl acetoacetate and the like. In addition, the other solvent (Z) can be used individually by 1 type or in mixture of 2 or more types.

  The total amount of the specific solvent (X) and the specific solvent (Y) is preferably 1 to 70% by weight, more preferably 5 to 60% by weight, and more preferably 10 to 55% by weight based on the total amount of the solvent. It is particularly preferred. By setting it in this range, it becomes possible to achieve both suppression of streak unevenness that occurs when the alignment agent is applied and narrow halo.

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

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of 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. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the film thickness of the coating film is too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics. It becomes.

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, a solid content concentration of 1.5 to 4.5% by weight is particularly preferable. In the case of the offset printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet system, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s. The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.
<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film of the present invention is formed by the liquid crystal aligning agent prepared as described above. Moreover, the liquid crystal display element of this invention comprises the liquid crystal aligning film formed using the liquid crystal aligning agent of this invention. The drive mode to which the liquid crystal display element of the present invention is applied is not particularly limited, and can be applied to various drive modes such as TN type, STN type, IPS type, FFS type, VA type, MVA type, and PSA type.

The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3). In step (1), the substrate to be used varies depending on the desired drive mode. Steps (2) and (3) are common to each drive mode.
[Step (1): Formation of coating film]
First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.

(1-1) When manufacturing a TN type, STN type, VA type, MVA type or PSA type liquid crystal display element, a pair of substrates each provided with a patterned transparent conductive film is used as a pair. The liquid crystal aligning agent of this invention is apply | coated on the formation surface of a transparent conductive film. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a method of using a mask having a desired pattern when forming a transparent conductive film, etc. be able to.

  The application method of the liquid crystal aligning agent of the present invention is not particularly limited, but it can be preferably performed by an offset printing method, a spin coating method, a roll coater method or an ink jet method. In particular, the liquid crystal aligning agent of the present invention is suitably used for ink-jet coating, thereby advantageously obtaining the effect of narrowing the frame of the liquid crystal panel by narrowing the region where the film thickness defect occurs at the end of the coating region as much as possible. be able to. In applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. It is also possible to perform a pretreatment to apply the above in advance.

  After the application of the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Thereafter, a firing (post-baking) step is performed for the purpose of completely removing the solvent and, if necessary, heat imidizing the amic acid structure or the amic acid ester structure present in the polymer. The firing temperature (post-bake temperature) at this time is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. Thus, the film thickness of the formed film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-2) When manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. The liquid crystal aligning agent of this invention is each apply | coated to one surface of the counter substrate which is not, and then a coating film is formed by heating each application surface. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

In both cases (1-1) and (1-2), after applying a liquid crystal aligning agent on the substrate, a coating film to be an alignment film is formed by removing the organic solvent. At this time, when the polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imide ring structure and an amic acid structure, It is good also as a more imidized coating film by advancing the dehydration ring-closing reaction by further heating after the coating film formation.
[Step (2): rubbing treatment]
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, the coating film formed in the above step (1) is fixed by a roll wound with a cloth made of fibers such as nylon, rayon, and cotton. A rubbing process that rubs in the direction is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the step (1) can be used as it is 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, a process for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays, After forming a resist film in part and performing a rubbing process in a direction different from the previous rubbing process, a process for removing the resist film is performed so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. Good. In this case, it is possible to improve the visibility characteristics of the obtained liquid crystal display element.

When manufacturing a PSA type liquid crystal display element, the following step (3) may be carried out using the coating film formed in the above step (1) as it is, but the fall of the liquid crystal molecules is controlled and the alignment is divided. A weak rubbing treatment may be performed for the purpose of performing the above in a simple manner.
[Step (3): Construction of liquid crystal cell]
(3-1) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above and disposing a liquid crystal between the two substrates facing each other. 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 respective liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface And after injecting and filling a liquid crystal in the cell gap divided by the sealing agent, a liquid crystal cell is manufactured by sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. In this method, for example, an ultraviolet light curable sealing material is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed, and a predetermined number of places on the liquid crystal alignment film surface are applied. After the liquid crystal is dropped on the other substrate, the other substrate is bonded so that the liquid crystal alignment film faces. A liquid crystal cell is manufactured by spreading the liquid crystal over the entire surface of the substrate and then irradiating the entire surface of the substrate with ultraviolet light to cure the sealant. Regardless of which method is used, the liquid crystal cell manufactured as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase, and then slowly cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal. It is desirable to do.

  As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenyl cyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals. Biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

(3-2) When manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in the above (3-1) except that a photopolymerizable compound is injected or dropped together with a liquid crystal. Thereafter, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates. The voltage applied here can be, for example, 5 to 50 V direct current or alternating current. Moreover, as light to irradiate, the ultraviolet-ray and visible light which contain light with a wavelength of 150-800 nm can be used, for example, However, The ultraviolet-ray containing light with a wavelength of 300-400 nm is preferable. As a light source of irradiation 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, or the like can be used. In addition, the ultraviolet rays in the above preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter diffraction grating. The irradiation dose of light, preferably less than 1,000 J / ^{m 2} or more 200,000 J / ^{m 2,} more preferably from 1,000~100,000J / ^{m 2.}

  And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned. When the rubbing treatment is performed on the coating film, the two substrates are arranged to face each other so that the rubbing directions in each coating film are at a predetermined angle, for example, orthogonal or antiparallel.

  The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, It can be used for display devices such as various monitors and liquid crystal televisions.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, the imidization ratio of polyimide in the polymer solution, the solution viscosity of the polymer solution, the weight average molecular weight of the polymer, and the epoxy equivalent were measured by the following methods.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting precipitate was sufficiently dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidation ratio [%] was determined by the following formula (x).

Imidation rate [%] = (1-A ¹ / A ² × α) × 100 (x)
(In Formula (x), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a polymer precursor (polyamic acid). The number ratio of other protons to one proton of NH group in)
[Solution viscosity of polymer solution]
The solution viscosity [mPa · s] of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer for a solution prepared to a polymer concentration of 10% by weight using a predetermined solvent.
[Weight average molecular weight of polymer]
The weight average molecular weight is a polystyrene equivalent value measured by gel permeation chromatography under the following conditions.

Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Epoxy equivalent]
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.

<Synthesis of polymer (A)>
[Synthesis Example 1: Synthesis of polyimide (PI-1)]
2,2.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic dianhydride and 8.6 g (0.08 mol) of p-phenylenediamine (PDA) as diamine ) And 10.5 g (0.02 mol) of cholestanyl 3, HC-diaminobenzoate (HCDA) are dissolved in 166 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours to obtain a polyamic acid. A solution containing 20% by weight was obtained. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 90 mPa · s.

  Next, NMP was added to the obtained polyamic acid solution to obtain a polyamic acid concentration of 7% by weight, 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. . After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP (by this operation, pyridine and acetic anhydride used in the dehydration cyclization reaction were removed from the system. The same applies hereinafter), whereby the imidation rate was about 68. A solution containing 26% by weight of polyimide (PI-1) was obtained. A small amount of the obtained polyimide solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 45 mPa · s.

[Synthesis Example 2: Synthesis of polyimide (PI-2)]
22.5 g (0.1 mol) of TCA as tetracarboxylic dianhydride, 6.1 g (0.04 mol) of 3,5-diaminobenzoic acid (35DAB) as diamine, cholestanyloxy-2,4-diaminobenzene ( HCODA) 5.0 g (0.010 mol) and compound (LDA) 9.3 g (0.020 mol) represented by the above formula (D-1-5), 4- (4-aminophenoxycarbonyl) -1 9.4 g (0.030 mol) of-(4-aminophenyl) piperidine (APPC) was 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. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 76 mPa · s.

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

[Synthesis Example 3: Synthesis of polyimide (PI-3)]
1,8.7 g (0.075 mol) of 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride (BODA) as tetracarboxylic dianhydride And 1.90 g (0.025 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CB), 10.7 g (0.07 mol) of 35DAB as a diamine and 1,3-diamino-4- { 4- [trans-4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene (PBCH5DAB, compound represented by the above formula (D-1-2)) 13.1 g (0.03 mol) , 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 collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 85 mPa · s.

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

[Synthesis Example 4: Synthesis of polyimide (PI-4)]
As tetracarboxylic dianhydride, 110 g (0.50 mol) of TCA and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) naphtho 160 g (0.50 mol) of [1,2-c] furan-1,3-dione, 91 g (0.85 mol) of p-phenylenediamine (PDA) as a diamine, 1,3-bis (3-aminopropyl) ) 25 g (0.10 mol) of tetramethyldisiloxane and 25 g (0.040 mol) of 3,6-bis (4-aminobenzoyloxy) cholestane, and 1.4 g (0.015 mol) of aniline as a monoamine, 960 g of NMP And a reaction was conducted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight 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 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 γ-butyrolactone to obtain about 2,500 g of a solution containing 15% by weight of polyimide (PI-4) having an imidation ratio of about 95%. A small amount of this solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 70 mPa · s.

[Synthesis Example 5: Synthesis of polyimide (PI-5)]
TCA 22.4 g (0.1 mol) as tetracarboxylic dianhydride, 8.6 g (0.08 mol) PDA as diamine, 2.0 g (0.01 mol) 4,4′-diaminodiphenylmethane and 4,4 ′ -3.2 g (0.01 mol) of diamino-2,2′-bis (trifluoromethyl) biphenyl was dissolved in 324 g of NMP, reacted at 60 ° C. for 4 hours, and a solution containing 10% by weight of polyamic acid was obtained. Obtained.

  Next, 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 dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new NMP to obtain a solution containing 10% by weight of polyimide (PI-5) having an imidization ratio of about 93%. A small amount of the obtained polyimide solution was taken and measured, and the solution viscosity was 30 mPa · s.

[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 12.2 g (0.08 mol) of 35 DAB and 9.8 g (0.02 mol) of HCODA. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 80 mPa · s.

  Next, imidization was performed by the same method as in Synthesis Example 1 to obtain a solution containing 26% by weight of polyimide (PI-6) having an imidization ratio of about 65%. A small amount of the obtained polyimide solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 40 mPa · s.

[Synthesis Example 7: Synthesis of polyamic acid (PA-1)]
CB 200 g (1.0 mol) as tetracarboxylic dianhydride, 2,2′-dimethyl-4,4′-diaminobiphenyl 210 g (1.0 mol) as diamine, NMP 370 g and γ-butyrolactone 3,300 g mixed It melt | dissolved in the solvent and reacted at 40 degreeC for 3 hours, and obtained the solution containing 10 weight% of polyamic acids (PA-1). The solution viscosity measured by separating a small amount of the obtained polyamic acid solution was 160 mPa · s.

[Synthesis Example 8: Synthesis of polyamic acid (PA-2)]
The tetracarboxylic dianhydride used is pyromellitic dianhydride (PMDA) 196 g (0.9 mol) and CB 19.6 g (0.1 mol), and the diamine is PDA 0.2 mol and 4,4 ′. A solution containing 10% by weight of polyamic acid (PA-2) was obtained in the same manner as in Synthesis Example 7 except that -diaminodiphenyl ether (DDE) was used. A solution viscosity of 170 mPa · s obtained by measuring a small amount of the resulting polyamic acid solution was 170 mPa · s.

[Synthesis Example 9: Synthesis of polyamic acid (PA-3)]
The tetracarboxylic dianhydride used was TMPG (following formula TMPG) 424 g (1.0 mol) and the diamine was 1,4-BABB (following formula 1,4-BAAB) 348 g (1.0 mol). Except for the above, a solution containing 10% by weight of polyamic acid (PA-3) was obtained by the same method as in Synthesis Example 7. A solution viscosity of 150 mPa · s obtained by measuring a small amount of the obtained polyamic acid solution was measured.

[Synthesis Example 10: Synthesis of polyorganosiloxane (APS-1)]
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (ECETS), 500 g of methyl isobutyl ketone and 10.0 g of triethylamine were added. Charged and mixed at room temperature. Next, 100 g of deionized water was dropped from the dropping funnel over 30 minutes, and the reaction was performed at 80 ° C. for 6 hours while stirring under reflux. After completion of the reaction, the organic layer is taken out, washed with 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure, thereby reactive polyorganosiloxane. (EPS-1) was obtained as a viscous transparent liquid. When this reactive polyorganosiloxane was subjected to ¹ H-NMR analysis, a peak based on an epoxy group was obtained in the vicinity of chemical shift (δ) = 3.2 ppm according to the theoretical intensity. Was confirmed not to happen. The obtained reactive polyorganosiloxane had a weight average molecular weight Mw of 3,500 and an epoxy equivalent of 180 g / mol.

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

<Preparation of liquid crystal aligning agent (1)>
[Example 1]
Polyimide (PI-1) is used as the polymer (A), and 1-butoxy-2-propanol (BP), diacetone alcohol (DAA) and N-methyl-2-pyrrolidone (NMP) are added as solvents to the polymer (A). The solvent composition was BP: DAA: NMP = 45: 5: 50 (weight ratio), and the solid content concentration was 3.5% by weight. A liquid crystal aligning agent (S-1) was prepared by filtering this solution using a filter having a pore diameter of 1 μm. The liquid crystal aligning agent (S-1) is mainly used for manufacturing a vertical alignment type liquid crystal display element.

[Inkjet applicability evaluation]
The liquid crystal aligning agent (S-1) prepared above was applied to a silicon wafer using an ink jet coating apparatus (manufactured by Shibaura Mechatronics Co., Ltd.). The coating conditions were such that the number of heads was 64 and the amount of dispensing was 0.2 g / head · second, and two reciprocating coatings (four coatings). Subsequently, the solvent was removed by heating (pre-baking) for 1 minute on an 80 ° C. hot plate to form a coating film having an average film thickness of 80 nm.

  Regarding the coating film formed on the silicon wafer, it was visually observed, ◯ when the streak unevenness was not observed, △ when the slight streak unevenness was observed, and × when the streak unevenness was observed in the plane. .

  The film formed on the silicon wafer is visually observed, and the width of the part where the film thickness is thinner than the center part at the edge of the film and the color tone is changed (the film thickness defective part) is measured. Halo evaluation was performed by the length of the width. In the Halo evaluation, the case where the width of the portion where the color tone is changed at the edge of the coating film is 2.9 mm or less is ◯, the case where the width is longer than 3.0 mm and is 3.9 mm or less is Δ, the width is The case where it was longer than 4.0 mm was evaluated as x. The results are shown in Table 1-1 below.

<Examples 2-8, Comparative Examples 1-5>
Liquid crystal aligning agents (S-2) to (S-13) in the same manner as in Example 1 except that the polymer (A), other components, and types and amounts of the solvents used were changed as shown in Table 1-1 above. Were prepared respectively. In addition, using each of the prepared liquid crystal aligning agents, a coating film was formed on the substrate in the same manner as in Example 1, and the Inkjet coatability was evaluated. The results are shown in Table 1-1.

<Example 9, Comparative Examples 6-7>
Liquid crystal aligning agents (S-14) to (S-16) in the same manner as in Example 1 except that the polymer (A), other components, and types and amounts of the solvents used were changed as shown in Table 1-2. Were prepared respectively.

[Printability evaluation]
About the liquid crystal aligning agent prepared above, the printability to a board | substrate was evaluated. Evaluation was performed as follows. First, about the prepared liquid crystal aligning agent (S-14), the liquid crystal aligning agent to an anilox roll is used for a liquid crystal aligning film printer (Nippon Photo Printing Co., Ltd., Angstromer type "S40L-532"). The operation of bringing the anilox roll into contact with the printing plate (hereinafter referred to as idle operation) was carried out 10 times in total under the condition of 20 drops (about 0.2 g).

  After ten blank runs, the main printing was subsequently performed using a silicon wafer. In this printing, after the idling operation, 10 substrates are loaded at intervals of 60 seconds, and each substrate after applying the liquid crystal aligning agent is heated (prebaked) at 80 ° C. for 1 minute to remove the solvent, and then 210 ° C. Was heated (post-baked) for 10 minutes to form a coating film having a thickness of about 80 nm. The printability was evaluated by observing this coating film with a microscope having a magnification of 20 times.

  Evaluation was carried out using the silicon wafer of the tenth printing after idling. Regarding the coating film formed on the silicon wafer, it was visually observed, ◯ when the streak unevenness was not observed, △ when the slight streak unevenness was observed, and × when the streak unevenness was observed in the plane. .

  The film formed on the silicon wafer is visually observed, and the width of the part where the film thickness is thinner than the center part at the edge of the film and the color tone is changed (the film thickness defective part) is measured. Halo evaluation was performed by the length of the width. The Halo evaluation is ◯ when the width of the portion where the color tone is changed at the edge of the coating film is 1.4 mm or less, Δ when the width is longer than 1.5 mm and 1.9 mm or less, and the width is 2. The case where it was longer than 0 mm was evaluated as x. The results are shown in Table 1-2.

  Similarly, Table 1-2 shows the results of evaluating the print coatability of the liquid crystal aligning agents (S-15) and (S-16).

In Table 1, the abbreviations for 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 BL: γ-butyrolactone

Claims (7)

A liquid crystal aligning agent comprising at least one polymer (A) selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and a solvent,
A specific solvent (X) in which the solvent is 1-butoxy-2-propanol;
A liquid crystal aligning agent containing a specific solvent (Y) containing at least one selected from the group consisting of diethylene glycol diethyl ether, diacetone alcohol, propylene glycol diacetate, and dipropylene glycol monomethyl ether.   The liquid crystal aligning agent of Claim 1 whose total amount of the said specific solvent (X) and a specific solvent (Y) is 1 to 70 weight% with respect to the total amount of solvents.   The liquid crystal aligning agent of Claim 1 or 2 whose content of the said specific solvent (X) is 10 to 90 weight% of the total amount of a specific solvent (X) and a specific solvent (Y).   The liquid crystal aligning agent of Claims 1-3 for application | coating by an inkjet system. The polymer (A) is a polymer obtained by a reaction between a tetracarboxylic dianhydride and a diamine compound,
As the tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8 -Containing at least one selected from the group consisting of dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, and cyclopentanetetracarboxylic dianhydride, Item 5. The liquid crystal aligning agent according to any one of Items 1 to 4.   The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-5. A liquid crystal display device comprising the liquid crystal alignment film according to claim 6.