Polyimide varnish

Abstract

The present invention provides a polyimide varnish suitable for forming a liquid crystal alignment film, etc., the polyimide varnish can suppress the phenomenon of whitening due to moisture absorption, has little viscosity change, and has excellent storage stability. In addition, it is not easy to produce foreign matter, clogging, etc. when obtaining the film, and the surface roughness of the obtained film is less. In addition, even if it is dried and heated, the original characteristics of the polyimide material can be obtained. A polyimide varnish is characterized in that it contains the following (A) components and (B) components. (A) component: polyimide (A) as an imide product of a polyimide precursor. (B) component: an amine compound (B) having any one of a secondary amino group or a tertiary amino group and any one of a nitrogen-containing aromatic heterocycle or an aromatic hydrocarbon group in the molecule, wherein the amino group is bonded to a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group.

Description

Technical Field

[0001] The present invention relates to a polyimide varnish which is suitable as a liquid crystal aligning agent and the like and can suppress whitening due to moisture absorption. Background Art

[0002] Polyimide is widely used as a protective material and insulating material in the electrical / electronic field due to its high mechanical strength, heat resistance and solvent resistance. Specifically, when used as an insulating film for semiconductors, a polyimide film with a thickness of 1 to 10 μm is usually formed on a silicon substrate processed by wiring, and when used as a liquid crystal alignment film, a polyimide film with a thickness of 0.05 to 0.2 μm is usually formed on a transparent substrate with a transparent electrode, and a thin polyimide film is formed on various supporting substrates for use. For forming the polyimide film, a polyimide varnish dissolved in a suitable organic solvent is usually applied to the substrate by spin coating, offset printing, gravure printing, flexographic printing, inkjet printing and the like, and the obtained coating is subjected to heat treatment.

[0003] Polyimide has excellent properties as various protective materials and insulating materials, but on the other hand, it has the disadvantage of poor solubility in organic solvents. Therefore, when dissolving polyimide in an organic solvent, organic polar solvents with high solubility such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, and hexamethylphosphoramide are generally used. However, these solvents have high solubility, but on the other hand, they have the disadvantage of high hygroscopicity.

[0004] Therefore, when a film is obtained using a polyimide varnish containing these organic solvents, the obtained film tends to be easily affected by the environment in which the coating is performed. In particular, when the coating is performed in an environment with high humidity, the solubility of the composition decreases due to moisture absorption before the heat treatment, the polyimide precipitates, and the film becomes white (hygroscopic whitening). In addition, even if the film that causes hygroscopic whitening is dried or heated, the original characteristics of the polyimide cannot be obtained, and the surface of the obtained film is rough.

[0005] Furthermore, when a film is obtained by flexographic printing using a polyimide varnish, the polyimide component may precipitate on the flexographic plate to produce printed foreign matter, or precipitate on the discharge head of the inkjet device to cause clogging of the head, resulting in process defects.

[0006] As a method for suppressing the hygroscopic whitening of the polyimide varnish and the precipitation of the polyimide component, it is proposed to use a high-boiling point solvent such as N-vinylpyrrolidone or N-cyclohexylpyrrolidone as more than 50% of the solvent (Patent Document 1). In addition, it is proposed to add a polyol compound having 3 to 15 carbon atoms and a tertiary nitrogen atom and a quaternary carbon atom to the polyimide varnish (Patent Document 2).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 5-117587

[0010] Patent document 2: International Publication (WO) No. 2011 / 129414 Summary of the invention

[0011] Problems to be solved by the invention

[0012] In view of the above situation, the object of the present invention is to provide a polyimide varnish suitable as a liquid crystal aligning agent, etc., which can suppress the hygroscopic whitening phenomenon, has little viscosity change, and has excellent storage stability. In addition, it is not easy to produce foreign matter, clogging, etc. when obtaining the film, and the surface roughness of the obtained film is less. In addition, even if drying and heating are performed, the original characteristics of the polyimide material can be obtained.

[0013] Solutions for solving problems

[0014] The inventors of the present invention have conducted intensive research to solve the above-mentioned problems, and as a result, they have noticed that the above-mentioned whitening can be eliminated by improving the water solubility of the polyimide in the varnish, and have found that in order to improve the water solubility of the polyimide, an amine compound having a secondary or tertiary amino group and a specific cyclic group is added to the polyimide varnish, thereby suppressing the hygroscopic whitening phenomenon. On the other hand, it is also known that when the above-mentioned amine compound is a primary amine compound, the viscosity of the varnish is unstable and the storage stability is significantly deteriorated.

[0015] The present invention has been accomplished based on the above-mentioned findings, and the gist of the present invention is as follows.

[0016] A polyimide varnish characterized by containing the following components (A) and (B).

[0017] (A) Component: polyimide (A) which is an imidation product of a polyimide precursor.

[0018] Component (B): an amine compound (B) having in the molecule a secondary amino group or a tertiary amino group and a nitrogen-containing aromatic heterocyclic group or a cyclic group of an aromatic hydrocarbon group, wherein the amino group is bonded to a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group.

[0019] Effects of the Invention

[0020] According to the present invention, a polyimide varnish is provided, which can suppress the whitening phenomenon due to moisture absorption, has little viscosity change, and is excellent in storage stability. In addition, when obtaining a film, it is not easy to generate foreign matter, block the discharge head of the inkjet device, etc., and the surface roughness of the obtained film is less. In addition, even if drying and heating are performed, the original characteristics of the polyimide material can be obtained.

[0021] The mechanism by which the above-mentioned effects of the present invention are obtained is not necessarily clear, but the following is considered to be one of the causes.

[0022] It is known that generally polyimide has low solubility, but in the case of partially imidized polyimide, carboxylic acid derived from tetracarboxylic dianhydride remains, so the water solubility can be improved by forming a salt between the carboxylic acid and the amine. By forming a salt between the amine and the polyimide, the precipitation of the polyimide when the polyimide varnish absorbs moisture can be suppressed.

[0023] On the other hand, polyimide is rich in electrophilic carbonyl groups, so it is easy to be attacked by nucleophilic agents such as aliphatic amine compounds. In particular, polyimide derived from aromatic tetracarboxylic dianhydride is easy to obtain a planar structure, with little steric hindrance, so it can be considered to be more susceptible to nucleophilic attack by aliphatic amines. Therefore, from the perspective of less viscosity change and ensuring storage stability, it is preferred to use alicyclic and aliphatic tetracarboxylic dianhydrides as raw materials for polyimide. By adopting such a scheme, the risk of aliphatic amines becoming nucleophilic agents and nucleophilic addition to polyimide can be reduced, and a polyimide varnish with less viscosity change and high storage stability can be obtained.

[0024] Furthermore, from the viewpoint of less viscosity change and ensuring storage stability, the basicity of the polyimide varnish is preferably low. By adopting such a configuration, a decrease in the molecular weight of the polyimide and a decrease in the viscosity of the polyimide varnish can be reduced.

[0025] The amine compound of the present invention having either a secondary amino group or a tertiary amino group in the molecule is considered to be less likely to cause nucleophilic attack due to large steric hindrance, but can suppress precipitation due to moisture absorption of the polyimide varnish by forming a salt of the amine and the carboxylic acid.

[0026] The polyimide varnish of the present invention is suitable as a protective material represented by a liquid crystal aligning agent, an insulating material, and the like. DETAILED DESCRIPTION

[0027] <Polyimide (A)>

[0028] The polyimide varnish of the present invention contains the following component (A).

[0029] (A) Component: polyimide (A) which is an imidation product of a polyimide precursor.

[0030] The polyimide (A) can be used alone or in combination of two or more.

[0031] The polyimide precursor is a substance that generates polyimide by imidization reaction such as polyamic acid and polyamic acid ester, and is preferably a polyamic acid obtained by (polycondensation) reaction of a tetracarboxylic acid component containing tetracarboxylic dianhydride or a derivative thereof with a diamine component. Examples of the derivative of tetracarboxylic dianhydride include tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid diester dichloride, and tetracarboxylic acid diester.

[0032] As tetracarboxylic dianhydride or its derivative, various tetracarboxylic dianhydride or its derivative can be used. Aromatic, non-cyclic aliphatic or alicyclic tetracarboxylic dianhydride or their derivatives can be listed above. Here, aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups containing at least one carboxyl group bonded to an aromatic ring. Non-cyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. Among them, it is not necessary to be composed only of a chain hydrocarbon structure, and alicyclic structure and aromatic ring structure can also be present in a part thereof. In addition, alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups containing at least one carboxyl group bonded to an alicyclic structure. Among them, none of these four carboxyl groups are bonded to an aromatic ring. In addition, it is not necessary to be composed only of an alicyclic structure, and a chain hydrocarbon structure and aromatic ring structure can also be present in a part thereof.

[0033] In the present invention, from the viewpoint of ensuring little viscosity change and storage stability, the tetracarboxylic acid derivative component preferably uses non-cyclic aliphatic or alicyclic tetracarboxylic dianhydride or their derivatives. Among them, it is more preferred to include tetracarboxylic dianhydride or their derivatives having at least one partial structure selected from the group consisting of cyclobutane ring structure, cyclopentane ring structure and cyclohexane ring structure. In addition, its usage is preferably 1 mol% or more, more preferably 5 mol% or more, and further preferably 10 mol% or more relative to 1 mol of all tetracarboxylic acid derivative components used. In the case where the above-mentioned tetracarboxylic acid derivatives include tetracarboxylic dianhydride or their derivatives other than the above-mentioned tetracarboxylic dianhydride and their derivatives, its upper limit is preferably 95 mol% or less, more preferably 90 mol% or less.

[0034] As the tetracarboxylic dianhydride or its derivative, among others, tetracarboxylic dianhydride or its derivative represented by the following formula (3) is preferably used.

[0035]

[0036] In the above formula (3), X represents a structure selected from the group consisting of the following (x-1) to (x-13).

[0037]

[0038] In the above formulas (x-1) to (x-13), R 1 ~R 4 R each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom, a fluorine atom, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group. 5 and R 6 Each independently represents a hydrogen atom or a methyl group. j and k are each independently an integer of 0 or 1, and A1 and A2 are each independently a single bond, -O-, -CO-, -COO-, a phenylene group, a sulfonyl group or an amide group. *1 is a bond to one anhydride group, and *2 is a bond to another anhydride group. Two A2s are optionally the same or different.

[0039] Among them, X is preferably any one of the above formulae (x-1) to (x-7) and (x-11) to (x-13).

[0040] More preferable specific examples of the above formula (x-1) include the following formulas (x1-1) to (x1-6): In the formulas, * represents a bonding bond.

[0041]

[0042] The usage ratio of the tetracarboxylic dianhydride or its derivative represented by the above formula (3) is preferably 1 mol% or more, more preferably 5 mol% or more, and further preferably 10 mol% or more relative to 1 mol of the tetracarboxylic acid component used. In the case where the above tetracarboxylic acid derivatives include tetracarboxylic dianhydride or their derivatives other than the tetracarboxylic dianhydride represented by the above formula (3) and their derivatives, the upper limit is preferably 95 mol% or less, more preferably 90 mol% or less.

[0043] The above-mentioned tetracarboxylic dianhydride or its derivative may be used alone or in combination of two or more.

[0044] On the other hand, the diamine component for obtaining the polyamic acid is not particularly limited, and various diamines can be used.

[0045] Among them, in the present invention, when polyimide is used as a liquid crystal alignment agent for a vertical alignment mode, as a diamine that exhibits high vertical alignment ability, it is preferred to use a diamine having at least one side chain structure selected from the group consisting of the following formulas (S1), (S2) and (S3) (hereinafter also referred to as a specific diamine).

[0046]

[0047] -X 3 -R 2 (S2)

[0048] -X 4 -R 3 (S3)

[0049] In the above formula (S1), X 1 and X 2 Each independently represents a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 -. wherein a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, and m1 is 1 to 2. From the viewpoint of the availability of raw materials and the ease of synthesis, X1 and X2 are each independently preferably a single bond, -(CH2) a -(a is an integer of 1 to 15), -O-, -CH2O- or -COO-, more preferably a single bond, -(CH2) a -(a is an integer of 1 to 10), -O-, -CH2O- or -COO-.

[0050] G1 and G2 each independently represent a divalent cyclic group selected from a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms. Any hydrogen atom on the cyclic group may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorinated alkyl group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. m and n each independently represent integers of 0 to 3, and the total of m and n is 1 to 6, more preferably 1 to 4.

[0051] Examples of the divalent aromatic group having 6 to 12 carbon atoms include phenylene, biphenyl structure, naphthalene, etc. Examples of the divalent alicyclic group having 3 to 8 carbon atoms include cyclopropylene, cyclohexylene, etc.

[0052] R 1represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. 1 Any hydrogen atom of is optionally substituted by a fluorine atom.

[0053] In X 1 , X 2 , G 1 , G 2 When there are two or more a1 and A1, two or more X 1 , X 2 , G 1 , G 2 , a1 and A1 are independently and arbitrarily the same or different.

[0054] Preferred specific examples of the above formula (S1) include the following formulas (S1-x1) to (S1-x7).

[0055]

[0056] In formulas (S1-x1) to (S1-x7), R 1 is an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms, and X p Indicates - (CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-, A1 is an oxygen atom or -COO-* (wherein the bond marked with "*" is a bond with (CH2) a2 bond), A2 is an oxygen atom or *-COO- (wherein the bond marked with "*" is bonded to (CH2) a2 bond), a1 and a3 are each independently an integer of 0 or 1, a2 is an integer of 1 to 10, and Cy is 1,4-cyclohexylene or 1,4-phenylene.

[0057] In the above formula (S2), X 3 It represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -COO-, or -OCO-. Among them, -CONH-, -NHCO-, -O-, -CH2O-, -COO-, or -OCO- is preferred from the viewpoint of liquid crystal orientation.

[0058] R 2 represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, forming R 2Any hydrogen atom of is optionally substituted with a fluorine atom. Among them, an alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms is preferred from the viewpoint of liquid crystal orientation.

[0059] As a preferred embodiment of formula [S2], X 3 is any of -O-, -CH2O-, -COO- or -OCO-, preferably R 2 In the case of an alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, it is more preferred that R 2 In the case of an alkyl group having 3 to 20 carbon atoms, R 2 Any hydrogen atom of is optionally substituted by a fluorine atom.

[0060] In the above formula (S3), X 4 It represents -CONH-, -NHCO-, -O-, -CH2O-, -OCH2-, -COO- or -OCO-.

[0061] R 3 It represents a structure having a steroid skeleton, and specific examples thereof include a structure having a skeleton represented by the following formula (st).

[0062]

[0063] As an example of the above formula (S3), the following formula (S3-x) can be mentioned.

[0064]

[0065] In formula (S3-x), X represents the above formula (X1), (X2) or (X3). In addition, Col represents one selected from the group consisting of the above formulas (Col1) to (Col4), and G represents the above formula (G1) or (G2). * represents a site bonded to another group.

[0066] As more preferable structures of the formula (S3), structures represented by the following formulae (S3-1) to (S3-6) are mentioned.

[0067]

[0068] (* indicates bonding position)

[0069] When specific examples of the specific diamine are given, diamines of the following formulas (V-1) to (V-13) will be mentioned.

[0070]

[0071]

[0072] Where, X v1 ~X v4 , X p1 ~X p8 Each independently represents -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-, X v5 Indicates -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-, X V6 ~X V7 , X s1 ~X s4 Each independently represents -O-, -CH2O-, -OCH2-, -COO- or -OCO-. a ~X f Each independently represents a single bond, -O-, -NH-, -O-(CH2) m -O-, -C(CH3)2-, -CO-, -COO-, -CONH-, -(CH2) m -, -SO2-, -O-C(CH3)2-, -CO-(CH2) m -, -NH-(CH2) m -, -NH-(CH2) m -NH-, -SO2-(CH2) m -、-SO2-(CH2) m -SO2-, -CONH-(CH2) m -、-CONH-(CH2) m -NHCO-, or -COO-(CH2) m -OCO-,R v1 ~R v4 , R 1a ~R 1h Each independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. m represents an integer of 1 to 8.

[0073] From the viewpoint of providing liquid crystal orientation, content of the specific diamine is preferably 5 to 95 mol %, more preferably 5 to 90 mol %, particularly preferably 5 to 80 mol % based on the whole diamine component.

[0074] The above-mentioned specific diamines can be used alone or in combination of two or more.

[0075] <Other diamines>

[0076] As the diamine for obtaining the polyamic acid, diamines other than the above-mentioned specific diamines (also referred to as other diamines) may be used. In addition, other diamines may be used alone or in combination of two or more.

[0077] Specific examples of other diamines include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro -4,4'-biphenyl, 3,3'-trifluoromethyl-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyl diphenylamine, 3,3'-sulfonyl diphenylamine, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4 '-Diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diaminobenzophenone, 2,3'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,4-bis(4-aminophenoxy)benzene, 1,3-Bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(methylene)]diphenylamine, 4,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,4'-[1,4-phenylenebis(methylene)]diphenylamine, 3,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,3'-[1,4-phenylenebis(methylene)]diphenylamine, 3,3'-[1,3-phenylenebis(methylene)]diphenylamine, 1,4-phenylenebis[(4-aminophenyl)methanone], 1,4-phenylenebis [(3-aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3-phenylenebis[(3-aminophenyl)methanone], 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, N,N'-(1,4-phenylene)bis(4-aminobenzamide), N,N'-(1,3-phenylene)bis(4-aminobenzamide), N, N'-(1,4-phenylene)bis(3-aminobenzamide), N,N'-(1,3-phenylene)bis(3-aminobenzamide), N,N'-bis(4-aminophenyl)terephthalamide, N,N'-bis(3-aminophenyl)terephthalamide, N,N'-bis(4-aminophenyl)isophthalamide, N,N'-bis(3-aminophenyl)isophthalamide, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)anthracene 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,5-bis(4-aminophenoxy)hexane, 1,5 ...3-aminophenoxy)hexane, 1,5-bis(4-aminophenoxy)hexane, 1,5-bis(3-aminophenoxy)hexane, 1,5-7-bis(4-aminophenoxy)heptane, 1,7-(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy) 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, diamines represented by the following formulas (NH-1) to (NH-8), diamines represented by the following formulas (Z-1) to (Z-14), diamines represented by the following formulas (R1) to (R5), and diamines having a radical initiating function such as diamines represented by the following formulas (5-1 ) to (5-11) having a group "-N(D)-" (D represents a protective group that is removed by heating and replaced by a hydrogen atom, preferably a tert-butoxycarbonyl group), diamines represented by the following formulas (Dp-1) to (Dp-6), aromatic diamines having a photopolymerizable group at the end such as 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallylaniline, Bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane and other alicyclic diamines, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and other aliphatic diamines.

[0078]

[0079]

[0080] (In formulas (R3) to (R5), n is an integer of 2 to 6.)

[0081]

[0082] (Boc represents tert-butoxycarbonyl.)

[0083]

[0084] The method for obtaining polyamic acid from the above-mentioned tetracarboxylic acid component and diamine component is carried out by a known method. That is, the reaction of the diamine component and the tetracarboxylic acid component is usually carried out in a solvent containing the diamine component and the tetracarboxylic acid component. As the solvent used at this time, as long as it is a solvent that dissolves the generated polyamic acid, there is no particular limitation.

[0085] Specifically, examples thereof include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, etc. In addition, when the polyamic acid has high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or solvents of the following formulas [D1] to [D3] can be used.

[0086]

[0087] (D 1 and D 2 It represents an alkyl group having 1 to 3 carbon atoms. 3 represents an alkyl group having 1 to 4 carbon atoms. )

[0088] These organic solvents may be used alone or in combination. Furthermore, even a solvent that does not dissolve the polyamic acid may be used in combination with the above-mentioned solvents as long as the generated polyamic acid does not precipitate.

[0089] The concentration of the polyamic acid in the reaction system is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoint that the polyamic acid is less likely to precipitate and a high molecular weight body is easily obtained.

[0090] The polyamic acid obtained as described above can be precipitated and recovered by injecting the reaction solution into a poor solvent while fully stirring. In addition, precipitation is performed several times, and after cleaning with a poor solvent, a powder of a refined polyamic acid can be obtained by normal temperature or heating and drying. The poor solvent is not particularly limited, and examples thereof include: water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene, etc.

[0091] Polyamic acid ester can be obtained by subjecting the above-mentioned polyamic acid to an esterification reaction using an esterifying agent, for example.

[0092] The polyimide (A) contained in the polyimide varnish of the present invention is obtained by imidizing the polyimide precursor such as the above-mentioned polyamic acid, polyamic acid ester, etc. In the polyimide (A), the repeating units possessed by the polyimide precursor are ring-closed, but the ratio of the ring-closed repeating units to the total repeating units possessed by the polyimide precursor (also referred to as the ring-closing rate or the imidization rate) does not necessarily need to be 100%, and is preferably 20% to 90%, and more preferably 30% to 80%. Within this range, it can be arbitrarily adjusted according to the use and purpose of the polyimide varnish.

[0093] When the polyimide varnish of this invention is a liquid crystal aligning agent for forming a liquid crystal aligning film, it is preferable that it is 20% to 95%, and, as for the imidization rate, it is more preferable that it is 30% to 95%.

[0094] The imidization of the polyimide precursor can be carried out by stirring polyamic acid in an organic solvent, in the presence of a basic catalyst and an acid anhydride. As an organic solvent, the organic solvent used during the above-mentioned polymerization reaction can be used. As a basic catalyst, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. can be listed. Wherein, pyridine has a suitable alkalinity for making the reaction progress, so it is preferred. In addition, as an acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. can be listed, wherein, when using acetic anhydride, the purification after the reaction ends becomes easy, so it is preferred.

[0095] The temperature during the imidization reaction is -20 to 140°C, preferably 0 to 100°C, and the reaction time is 0.5 to 100 hours, preferably 1 to 80 hours. The amount of the basic catalyst is 0.5 to 30 times by mole of the amic acid, preferably 2 to 20 times by mole, and the amount of the acid anhydride is 1 to 50 times by mole of the amic acid, preferably 3 to 30 times by mole. The imidization rate of the obtained polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time.

[0096] Since the added catalyst and the like remain in the solution after the imidization reaction of the polyamic acid, it is preferred to recover the obtained polyimide by the method described below, redissolve it in an organic solvent, and use it as a component of the liquid crystal aligning agent of the present invention.

[0097] The polyimide solution obtained as described above can be poured into a poor solvent while being sufficiently stirred to precipitate a polymer. The precipitate can be filtered out, washed several times with a poor solvent, and then dried at room temperature or by heating to obtain a purified polyimide powder.

[0098] In consideration of the strength of the film obtained from the polyimide varnish thus obtained, the workability during film formation, and the coating properties, the molecular weight of the polyimide obtained as described above is preferably 2000 to 1000000 by weight average molecular weight (Mw) measured by GPC (Gel Permeation Chromatography), more preferably 10000 to 150000. In addition, the number average molecular weight (Mn) is preferably 3000 to 100000, more preferably 10000 to 50000.

[0099] <Amine compound (B)>

[0100] The polyimide varnish of the present invention comprises the following component (B).

[0101] Component (B): an amine compound (B) having in the molecule a secondary amino group or a tertiary amino group and a nitrogen-containing aromatic heterocyclic group or a cyclic group of an aromatic hydrocarbon group, wherein the amino group is bonded to a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group.

[0102] The amine compound (B) can be used alone or in combination of two or more.

[0103] The amine compound (B) is preferably a compound represented by the following formula (1).

[0104]

[0105] In the above formula (1), R1 and R2 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and at least one of R1 and R2 represents an alkyl group having 1 to 5 carbon atoms.

[0106] The alkyl group having 1 to 5 carbon atoms may be linear or branched, and preferred examples thereof include methyl, ethyl, propyl, butyl, isobutyl, sec-butyl, tert-butyl, and pentyl.

[0107] Ar represents a monovalent group having a nitrogen-containing aromatic heterocycle or an aromatic hydrocarbon group. The hydrogen atom on the nitrogen-containing aromatic heterocycle or the hydrogen atom on the aromatic hydrocarbon group possessed by Ar may be substituted by an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an alkyl group containing a halogen atom, an alkoxy group containing a halogen atom, a carboxyl group, a hydroxyl group, or a nitrile group.

[0108] Preferred examples of the nitrogen-containing aromatic heterocycle include cyclic structures containing at least one partial structure selected from the group consisting of the following formulae [1a], [1b], and [1c]. More preferred examples include cyclic structures containing one to four of the above partial structures.

[0109]

[0110] (wherein Y1 is a straight or branched alkyl group having 1 to 5 carbon atoms)

[0111] More preferred examples of nitrogen-containing aromatic heterocycles include: pyrrole ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, pyrazoline ring, isoquinoline ring, carbazole ring, purine ring, thiadiazole ring, pyridazine ring, triazine ring, triazole ring, pyrazine ring, benzimidazole ring, phenanthroline ring, indole ring, quinoline ring, benzothiazole ring, phenothiazine ring, oxadiazole ring, and acridine ring.

[0112] Preferred examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an azulene ring, an indene ring, a fluorene ring, an anthracene ring, a phenanthrene ring, and a phenalene ring.

[0113] X represents a divalent organic group containing a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group. X is preferably a divalent non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group. As preferred examples of non-cyclic aliphatic hydrocarbon groups, linear or branched alkylene groups having 1 to 10 carbon atoms or unsaturated alkylene groups having 1 to 10 carbon atoms can be cited. As preferred examples of non-aromatic cyclic hydrocarbon groups, alicyclic hydrocarbon groups having 3 to 20 carbon atoms such as cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, cycloundecane ring, cyclododecane ring, cyclotridecane ring, cyclotetradecane ring, cyclopentadecane ring, cyclohexadecane ring, cycloheptadecane ring, cyclooctadecane ring, cyclononadecane ring, cycloeicosane ring, tricycloeicosane ring, bicycloheptane ring, decahydronaphthalene ring, norbornene ring, and adamantane ring can be cited.

[0114] Among them, X is preferably a group represented by *1-X1-X2-*2 because of the ease of synthesis and the availability of raw materials.

[0115] Among them, X1 represents a divalent group containing a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group having 1 to 10 carbon atoms. X1 is preferably a divalent non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group having 1 to 10 carbon atoms. Preferred examples of the non-cyclic aliphatic hydrocarbon group or the non-aromatic cyclic hydrocarbon group of X1 are the same as the examples of X described above.

[0116] X2 is a single bond, -O-, -NH-, -S-, -SO2-, or a divalent organic group having 1 to 19 carbon atoms. The total number of carbon atoms in X1 and X2 is 1 to 20, preferably 1 to 10.

[0117] Note that *1 is a bond to N in formula (1), and *2 is a bond to Ar in formula (1).

[0118] N to which R1 and R2 are bonded is bonded to the above-mentioned non-cyclic aliphatic hydrocarbon group or non-aromatic cyclic hydrocarbon group.

[0119] Preferred examples of the amine compound (B) include compounds represented by the following formulae (b-1) to (b-14).

[0120]

[0121] Among them, the amine compound (B) is preferably one or more compounds represented by any of the above formulae (b-1) to (b-3) for reasons of ease of production and availability of raw materials.

[0122] <Polyimide varnish>

[0123] The polyimide varnish of the present invention contains the polyimide (A) as the component (A) and the amine compound (B) as the component (B). The polyimide varnish can be obtained, for example, by dispersing or dissolving these components in an organic solvent.

[0124] The total content of the polyimide (A) in the polyimide varnish is preferably 1 to 20% by mass, more preferably 1 to 15% by mass, and particularly preferably 1 to 10% by mass, from the viewpoint of easy uniform mixing with the compound (B).

[0125] Furthermore, from the viewpoint of efficiently obtaining the effects of the present invention and improving the stability of the polyimide varnish, the content of the amine compound (B) as the component (B) in the polyimide varnish is preferably 0.1 to 40 parts by mass, more preferably 0.1 to 30 parts by mass, and particularly preferably 0.1 to 10 parts by mass relative to 100 parts by mass of the polyimide (A).

[0126] The organic solvent that may be contained in the polyimide varnish of the present invention is an organic solvent that disperses or dissolves the polyimide (A) as the component (A) and the amine compound (B) as the component (B), and preferably dissolves them.

[0127] Examples of the organic solvent include: lactone solvents such as γ-valerolactone and γ-butyrolactone; lactam solvents such as γ-butyrolactam, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, tetramethylurea, and N,N-diethylformamide; 4-hydroxy-4-methyl-2-pentanone, diisobutyl ketone (2 , 6-dimethyl-4-heptanone), methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isopentyl lactate, n-butyl acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, malonic acid monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, ethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-isopropyl ether, ethylene glycol mono-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, Propylene glycol monobutyl ether, propylene glycol diacetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, isoamyl propionate, isoamyl isobutyrate, diisopropyl ether, diisoamyl ether; carbonate solvents such as ethylene carbonate and propylene carbonate; 1-hexanol, cyclohexanol, 1,2-ethylene glycol, diisobutylcarbinol (2,6-dimethyl-4-heptanol), cyclohexanone, cyclopentanone, etc.

[0128] Preferred combinations of two or more organic solvents include: N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol mono-n-butyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl- 2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and Propylene glycol diacetate, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl carbinol, N-methyl- 2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether, N,N-dimethylpropionamide and propylene glycol diacetate, tetramethyl urea and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monomethyl ether, etc.

[0129] The polyimide varnish of the present invention may contain various components (also referred to as other components) in addition to the polyimide (A) component and the component (B) as described above, depending on the application. Examples thereof include: other polymers other than the polyimide (A), antioxidants (phenolic, phosphite, thioether, etc.), ultraviolet absorbers, hindered amine light stabilizers, nucleating agents, resin additives (fillers, talc, glass fibers, etc.), flame retardants, processability improvers / lubricants, etc.

[0130] <Liquid crystal alignment agent>

[0131] In the case of a liquid crystal aligning agent as a suitable use of the polyimide varnish of the present invention, it is preferably prepared so as to be suitable for forming a liquid crystal aligning film. The liquid crystal aligning agent of the present invention preferably contains the polyimide varnish of the present invention.

[0132] The liquid crystal alignment agent of the present invention can be obtained, for example, by dispersing or dissolving the polyimide varnish of the present invention and other components as needed in an organic solvent. In addition, the liquid crystal alignment agent of the present invention can also be obtained by mixing two or more liquid crystal alignment agents. For example, it can be obtained by mixing two or more liquid crystal alignment agents containing the polyimide varnish of the present invention, or it can be obtained by mixing the liquid crystal alignment agent containing the polyimide varnish of the present invention with a liquid crystal alignment agent containing other components. As the above-mentioned other components, for example, other polymers other than the above-mentioned polyimide (A), cross-linking compounds, functional silane compounds, surfactants, compounds having photopolymerizable groups, organic solvents, etc. can be listed.

[0133] Other polymers are not particularly limited, and examples thereof include polyimide precursors such as polyamic acid and polyamic acid esters, polysiloxanes, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polymers of monomers having polymerizable unsaturated bonds, etc. As other polymers, polymers of monomers having polymerizable unsaturated bonds are preferably used. It should be noted that other polymers may be used alone or in combination of two or more.

[0134] When other polymers are used, the usage ratio is preferably 50% by mass or less, more preferably 0.1 to 40% by mass, and even more preferably 0.1 to 30% by mass, based on the total amount of the polymers contained in the polyimide varnish.

[0135] Examples of the monomer having a polymerizable unsaturated bond include: (meth)acrylic acid compounds (including unsaturated carboxylic acids, unsaturated carboxylic acid esters, and unsaturated polycarboxylic acid anhydrides), (meth)acrylamide compounds, aromatic vinyl compounds, conjugated diene compounds, maleimide group-containing compounds, α-methylene-γ-butyrolactone compounds, vinyl compounds other than aromatic vinyl compounds, and compounds containing a maleic anhydride structure.

[0136] Examples of polymers containing a compound having a maleic anhydride structure include poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, and poly(vinyl ether-maleic anhydride) copolymers. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, 2000, and 3000 (manufactured by Cray Valley Co., Ltd.) and GSM301 (manufactured by Gifu Shellac Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include ISOBAM-600 (manufactured by Kuraray Co., Ltd.). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include GANTREZ AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by ISP Japan Co., Ltd.).

[0137] In the polymer of the (meth)acrylic compound (hereinafter also referred to as polymer (uA)), the (meth)acrylic compound may be used in an amount of 50 mol % or more or 60 mol % or more based on the total amount of monomers used in the synthesis.

[0138] The polymer (uA) can be obtained, for example, by polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. As the polymerization initiator used, for example, azo compounds such as 2,2'-azobis(isobutyronitrile) and 2,2'-azobis(2,4-dimethylvaleronitrile) can be listed. The proportion of the polymerization initiator used is preferably 0.01 to 30 parts by mass relative to 100 parts by mass of all monomers used in the reaction. The above-mentioned polymerization reaction is preferably carried out in an organic solvent. As the organic solvent used in the reaction, for example, alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, etc. can be listed, preferably diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate, etc. The reaction temperature is preferably 30 to 120°C. The amount of the organic solvent used (a) is preferably an amount of 0.1 to 60% by mass of the total amount (b) of the monomers used in the reaction relative to the total amount (a+b) of the reaction solution.

[0139] As the monomer for obtaining the polymer (uA), a monomer represented by the following formula (S-mA), a monomer having a carboxyl group and a polymerizable unsaturated bond, a monomer having an epoxy skeleton and a polymerizable unsaturated bond, and other monomers having other polymerizable unsaturated bonds can be used.

[0140] PXJ (S-mA) (P represents a (meth)acryloyloxy group, a styryl group, a vinyloxy group (CH2=CH-O-), a maleimide group, or an α-methylene-γ-butyrolactone structure. X represents a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1-(a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, and m1 is an integer of 1 to 2. When m1 is 2, multiple a1s and A1s each independently have the above definition), or a group "-L-OCO-CR'=CR"-". Where P is a (meth)acryloyloxy group, a vinyloxy group (CH2=CH-O-), or a maleimide group, X represents a single bond or a linking group bonded to P via a carbon atom. J represents a structure selected from an alicyclic hydrocarbon group having 4 to 40 carbon atoms and an aromatic hydrocarbon group having 6 to 40 carbon atoms ) A monovalent organic group of at least one group selected from the group consisting of halogen atoms, alkyl groups containing halogen atoms, alkoxy groups containing halogen atoms, alkyl groups having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, alkenyl groups having 3 to 10 carbon atoms, and heteroatom-containing groups in which the carbon-carbon bond of any methylene group of the above-mentioned alkyl groups containing halogen atoms, alkoxy groups containing halogen atoms, alkyl groups, alkoxy groups, and alkenyl groups is interrupted by an oxygen atom.

[0141] It should be noted that, when J in the above formula (S-mA) is a monovalent organic group having two or more groups selected from the group consisting of at least one alicyclic hydrocarbon group having 4 to 40 carbon atoms and an aromatic hydrocarbon group having 6 to 40 carbon atoms, as long as at least one alicyclic hydrocarbon group or aromatic hydrocarbon group has the above-mentioned substituent, the other alicyclic hydrocarbon groups or aromatic hydrocarbon groups possessed by J in the above formula (S-mA) may be unsubstituted or have substituents other than those exemplified above.

[0142] In the group "-L-OCO-CR'=CR"-", L represents a single bond or -(B1-(CH2) b1 ) m’ -(b1 is an integer of 1 to 15. B1 represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO- or -OCO-. m' is an integer of 1 to 2. When m' is 2, multiple b1s and B1s each independently have the above definition, and at least one B1 represents a linking group other than a single bond). R', R" represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0143] As more preferable specific examples of the above group "-X-J", groups represented by any of the following formulae (S1) to (S2) can be mentioned.

[0144]

[0145] (X 1 Represents a single bond, -(CH2) a-(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO-, -((CH2) a1 -A1) m1 -(a1 is an integer of 1 to 15. A1 represents an oxygen atom or -COO-, and m1 is an integer of 1 to 2. When m1 is 2, a plurality of a1s and A1s each independently have the above definition), or a group "-L-OCO-CR'=CR"-".G 1 represents a divalent cyclic group selected from a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms and a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms. Any hydrogen atom on the cyclic group may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorinated alkyl group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. m is an integer of 1 to 4. When m is 2 or more, multiple X 1 , G 1 Each independently has the above definition. 1 represents a fluorine atom, an alkyl group having 1 to 10 carbon atoms and containing a fluorine atom, an alkoxy group having 1 to 10 carbon atoms and containing a fluorine atom, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or an alkoxyalkyl group having 3 to 10 carbon atoms. In the group "-L-OCO-CR'=CR"-", L represents a single bond or -(B1-(CH2) b1 ) m '-(b1 is an integer of 1 to 15. B1 represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO- or -OCO-. m' is an integer of 1 to 2. When m' is 2, multiple b1s and B1s each independently have the above definition, and at least one B1 represents a linking group other than a single bond).

[0146] In the group "-L-OCO-CR'=CR"-", the above R' and R" represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0147] *-X2-G2 (S2)

[0148] (X 2 Indicates -CONH-, -NHCO-, -O-, -CH2O-, -OCH2-, -COO- or -OCO-. 2Represents a structure having a steroid skeleton. At least one of the hydrogen atoms in the structure having a steroid skeleton is substituted by a substituent selected from the group consisting of a halogen atom, an alkyl group containing a halogen atom, an alkoxy group containing a halogen atom, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, and a heteroatom-containing group in which the carbon-carbon bond of any methylene group of the above-mentioned alkyl group containing a halogen atom, an alkoxy group containing a halogen atom, an alkyl group, an alkoxy group, and an alkenyl group is interrupted by an oxygen atom.)

[0149] In the above formula (S1), as G 1 The divalent cyclic group in the formula (a) includes, for example, cyclopropylene, cyclohexylene, and phenylene. Any hydrogen atom on these cyclic groups may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorinated alkyl group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms, or a fluorine atom.

[0150] In the above formula (S2), as G 2 Examples of the structure having a steroid skeleton include a structure containing a cholestanyl group, a cholesterol group, or a lanostanyl group.

[0151] Specific examples of the monomer having a carboxyl group and a polymerizable unsaturated bond include: carboxyl group-containing (meth)acrylate compounds such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, 2-hydroxyethyl (meth)acrylate, 2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, 5-carboxypentyl (meth)acrylate, 2-acryloyloxyethyl succinate, and 2-methacryloyloxyethyl succinate; vinyl group-containing aromatic carboxylic acids such as 4-vinylbenzoic acid; carboxyl group-containing maleimides such as 4-maleimidobenzoic acid; and carboxyl group-containing (meth)acrylamide compounds such as N-(carboxyphenyl)methacrylamide and N-(carboxyphenyl)acrylamide.

[0152] Examples of the monomer having an epoxy skeleton and a polymerizable unsaturated bond include allyl glycidyl ether, glycidyl (meth)acrylate, 2-methyl glycidyl (meth)acrylate, α-ethyl glycidyl (meth)acrylate, α-n-propyl glycidyl (meth)acrylate, α-n-butyl glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3-vinyl-7-oxabicyclo[4.1.0]heptane, 1,2-epoxy-5-hexene, and 1,7-octadiene monoepoxy compounds.

[0153] Examples of the monomer having other polymerizable unsaturated bonds include the following monomers.

[0154] (Meth)acrylate compounds containing amino groups such as aminoethyl (meth)acrylate and aminopropyl (meth)acrylate; (meth)acrylamide compounds containing hydroxymethyl or alkoxymethyl groups such as N-hydroxymethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide; 3-(acryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)oxetane, 3-(acryloyloxymethyl)-2-methyloxetane, 3-(methacryloyloxymethyl) Compounds having an oxetane skeleton such as 2-(2-pyridylcarbonyloxy)ethyl (meth)acrylate, 2-(3-pyridylcarbonyloxy)ethyl (meth)acrylate, and 2-(4-pyridylcarbonyloxy)ethyl (meth)acrylate; methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, benzyl (meth)acrylate, Phenyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 2-ethoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-propyl-2-adamantyl (meth)acrylate, 8-methyl-8-tricyclodecanyl (meth)acrylate, and (meth)acrylate. ) (Meth)acrylate compounds such as 8-ethyl-8-tricyclodecyl acrylate; (meth)acrylamide compounds such as acrylamide, methacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide; vinyl ether compounds such as methyl vinyl ether, benzyl vinyl ether, vinylnaphthalene, vinylcarbazole; aromatic vinyl compounds such as styrene, methylstyrene, chlorostyrene and bromostyrene; maleimide group-containing compounds such as maleimide, N-methylmaleimide, N-phenylmaleimide and N-cyclohexylmaleimide.

[0155] As a monomer component for obtaining the polymer (uA), the total amount of the monomer having a carboxyl group and a polymerizable unsaturated bond, the monomer having an epoxy skeleton and a polymerizable unsaturated bond, and the monomer represented by the above formula (S-mA) is preferably 10 mol% or more, preferably 20 mol% or more. In the case of using the above monomer having other polymerizable unsaturated bonds, the total amount of the monomer having a carboxyl group and a polymerizable unsaturated bond and the monomer represented by the above formula (S-mA) is preferably 99 mol% or less, preferably 95 mol% or less, and more preferably 90 mol% or less.

[0156] The molecular weight of the polymer (uA) obtained as described above is preferably 2,000 to 1,000,000, more preferably 10,000 to 150,000, as measured by GPC (Gel Permeation Chromatography) method, and the number average molecular weight (Mn) is preferably 3,000 to 100,000, more preferably 10,000 to 50,000.

[0157] The crosslinking compound can be used for the purpose of improving the strength of the liquid crystal alignment film. Examples of the crosslinking compound include compounds having a hydroxyalkylamide bond described in Japanese Patent Application Laid-Open No. 2016-118753 and WO2015 / 156314, compounds having an alkoxyalkylamide bond, compounds having at least one group selected from the group consisting of an epoxy group, an oxetane group, a hydroxyl group, a hydroxyalkyl group, an isocyanate group, a cyclocarbonate group, and a lower alkoxyalkyl group described in paragraphs

[0109] to

[0113] of WO2016 / 047771, and compounds having a blocked isocyanate group.

[0158] Preferred examples of the compound having an epoxy group 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, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as EPIKOTE 828 (manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol F type epoxy resins such as EPIKOTE 807 (manufactured by Mitsubishi Chemical Co., Ltd.), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Co., Ltd.), and YX6954BH30 (manufactured by Mitsubishi Chemical Co., Ltd.). Epoxy resins containing a biphenyl skeleton such as EPPN-201 (manufactured by Nippon Explosives Co., Ltd.), phenol novolac type epoxy resins such as EOCN-102S (manufactured by Nippon Explosives Co., Ltd.), triglycidyl isocyanurate such as TEPIC (manufactured by Nissan Chemical Co., Ltd.), alicyclic epoxy resins such as Celloxide 2021P (manufactured by Daicel Chemical Industries, Ltd.), N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and tetrakis(glycidyloxymethyl)methane.

[0159] The blocked isocyanate compound is commercially available, and for example, CORONATE APstable M, CORONATE 2503, 2515, 2507, 2513, 2555, MILLIONATE MS-50 (all manufactured by Tosoh Corporation), TAKENATE B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.) and the like can be preferably used.

[0160] Specific examples of preferred crosslinking compounds include compounds represented by the following formulae (CL-1) to (CL-11).

[0161]

[0162]

[0163] The above is an example of the crosslinking compound, but the invention is not limited thereto. Moreover, the crosslinking compound used for the liquid crystal aligning agent of the present invention may be combined with two or more kinds of the crosslinking compound.

[0164] As for content of the crosslinking compound in a liquid crystal aligning agent, 0.1-150 mass parts is preferable with respect to 100 mass parts of all polymer components, 0.1-100 mass parts is more preferable, and 1-50 mass parts is particularly preferable.

[0165] The functional silane compound can be used for the purpose of improving the adhesion between the liquid crystal alignment film and the base substrate. As a specific example, the silane compound described in paragraph

[0019] of International Publication Gazette 2014 / 119682 can be cited. The content of the functional silane compound is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the total polymer components.

[0166] Surfactants can be used to improve the uniformity of the film thickness and surface smoothness of the liquid crystal alignment film. Examples of surfactants include fluorine-based surfactants, silicone-based surfactants, nonionic surfactants, and the like. Specific examples thereof include the surfactants described in paragraph

[0117] of WO2016 / 047771. The amount of surfactant used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of all polymers contained in the liquid crystal alignment agent.

[0167] Examples of the compound having a photopolymerizable group include compounds having one or more polymerizable unsaturated groups such as an acrylate group or a methacrylate group in the molecule, and examples thereof include compounds represented by any of the following formulae (M-1) to (M-7).

[0168]

[0169] As the organic solvent which may be contained in the liquid crystal aligning agent, the organic solvents described in the polyimide varnish can be used, and the type and content of the solvent can be appropriately selected according to the coating device, coating conditions, coating environment, and the like of the liquid crystal aligning agent.

[0170] The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of components other than the organic solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably 1 to 10 mass %.

[0171] The particularly preferred solid content concentration varies depending on the method used when applying the liquid crystal alignment agent on the substrate. For example, in the case of spin coating, it is particularly preferably 1 to 10% by mass. In the case of printing, it is particularly preferably 3 to 9% by mass, and thus it is particularly preferred to make the solution viscosity 12 to 50 mPa·s. In the case of inkjet method, it is particularly preferably 1 to 5% by mass, and thus it is particularly preferred to make the solution viscosity 3 to 15 mPa·s.

[0172] The liquid crystal alignment agent can be applied on a substrate, fired, and then used as a liquid crystal alignment film by rubbing, light irradiation, etc. In addition, in the case of vertical alignment, it can be used as a liquid crystal alignment film even without alignment treatment.

[0173] The substrate used at this time is not particularly limited as long as it is a substrate with high transparency. In addition to glass substrates, plastic substrates such as acrylic substrates, polycarbonate substrates, and PET (polyethylene terephthalate) substrates, and their films can also be used. In addition, from the viewpoint of process simplification, it is preferred to use a substrate formed with metal electrodes such as ITO electrodes, IZO (Indium Zinc Oxide: Indium Zinc Oxide) electrodes and IGZO (Indium Gallium Zinc Oxide: Indium Gallium Zinc Oxide) electrodes for driving liquid crystals, and an organic conductive film. In addition, in the case of a reflective liquid crystal display element, if only on one side of the substrate, a substrate formed with a metal or dielectric multilayer film such as a silicon wafer, aluminum, etc. can be used.

[0174] The coating method of the liquid crystal alignment agent is not particularly limited, and is generally performed industrially by screen printing, offset printing, flexographic printing, or inkjet method, etc. Other coating methods include dipping, roll coating, slit coating, spin coating, or spray coating, and these methods can be used according to the purpose.

[0175] After coating the liquid crystal alignment agent on the substrate, a heating unit such as a heating plate, a heat circulation oven or an IR (infrared) oven is used to evaporate the solvent at a temperature of 30 to 300° C., preferably 30 to 250° C., to form a liquid crystal alignment film, depending on the solvent used in the liquid crystal alignment agent.

[0176] The thickness of the liquid crystal alignment film after firing is preferably 5 to 300 nm, more preferably 10 to 200 nm, because if it is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease.

[0177] When the liquid crystal is horizontally aligned or tiltedly aligned, the liquid crystal alignment film after baking is processed by brushing, polarized ultraviolet ray irradiation, or the like.

[0178] As the ultraviolet rays, ultraviolet rays containing light with a wavelength of 300 to 400 nm are preferred. As the light source of the 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, etc. can be used. The ultraviolet rays in the preferred wavelength range can be obtained by using the light source together with, for example, a filter, a diffraction grating, etc. As the irradiation amount of light, 1000 J / m 2 Above and less than 100000J / m 2 , more preferably 1000 to 50000 J / m 2 .

[0179] The liquid crystal used in the liquid crystal display element is not particularly limited, and for example, nematic liquid crystal, smectic liquid crystal or cholesteric liquid crystal can be used. In this case, liquid crystal having positive or negative dielectric anisotropy can be selected according to the mode of the liquid crystal display element. In addition, a dichroic dye can be dissolved in a liquid crystal to prepare a guest-host type liquid crystal display element.

[0180] The liquid crystal aligning film obtained from the liquid crystal aligning agent of the present invention can be used as a liquid crystal aligning film for a horizontal alignment type or vertical alignment type liquid crystal display element.

[0181] As a liquid crystal orientation film for a horizontally aligned liquid crystal display element, it is suitable as a liquid crystal orientation film for a lateral electric field liquid crystal display element such as an IPS mode and an FFS mode, or a liquid crystal orientation film for a horizontally aligned liquid crystal display element such as a TN mode, and is particularly useful as a liquid crystal orientation film for an FFS mode liquid crystal display element.

[0182] As for the liquid crystal alignment film obtained by the liquid crystal alignment agent of the present invention, the liquid crystal alignment film for a vertically aligned liquid crystal display element such as a VA mode or a PSA mode is preferred. In addition, the liquid crystal alignment film for a vertically aligned liquid crystal display element such as a VA mode or a PSA mode can also be obtained by using an alignment treatment including a photo-alignment treatment. The preferred schemes of the light irradiated in the photo-alignment treatment, the light source, and the irradiation amount of the light are as described above.

[0183] In addition, the liquid crystal orientation film obtained from the liquid crystal orientation agent containing the polyimide varnish of the present invention can also be used for a liquid crystal orientation film for a phase difference film, a liquid crystal orientation film for a scanning antenna, a liquid crystal array antenna, or a liquid crystal orientation film for a transmission scattering type liquid crystal dimming element, or uses other than these, such as a protective film for a color filter, a gate insulating film for a flexible display, and a substrate material.

[0184] The liquid crystal display element using the liquid crystal alignment agent of the present invention can be applied to various devices, such as clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, portable video cameras (camcorders), PDAs, digital cameras, mobile phones, smart phones, various monitors, liquid crystal televisions, information displays, etc.

[0185] Example

[0186] The following is a further detailed description based on examples, but the present invention is not limited to these examples. The abbreviations of the compounds used below and the measurement methods and the like are as follows.

[0187] (Tetracarboxylic dianhydride)

[0188] BODA: bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic dianhydride.

[0189] CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0190] PMDA: pyromellitic anhydride.

[0191] TCA: 2,3,5-tricarboxycyclopentylacetic dianhydride.

[0192] TDA: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride.

[0193] 13DM-CBDA: 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0194]

[0195] (Diamine)

[0196] PDA: p-phenylenediamine.

[0197] DBA: 3,5-diaminobenzoic acid.

[0198] 3AMPDA: 3,5-diamino-N-(pyridin-3-ylmethyl)benzamide.

[0199]

[0200] A vertically aligning diamine represented by the following formula DA-1.

[0201]

[0202] Diamines represented by the following formulae DA-2 to DA-9.

[0203]

[0204] (Boc represents tert-butoxycarbonyl.)

[0205] (Methacrylic acid compound)

[0206] Methacrylic acid compounds represented by the following formulae MA-1 to MA-3.

[0207]

[0208] (Free Radical Polymerization Initiator)

[0209] AIBN: azobisisobutyronitrile.

[0210] <Solvent>

[0211] NMP: N-methyl-2-pyrrolidone, BCS: butyl cellosolve.

[0212] <Amine compound (B)>

[0213] 3AMP: 3-aminomethylpyridine, Me-3AMP: N-methyl-3-aminomethylpyridine. MBA: N-methylbenzylamine, DMBA: N, N-dimethylbenzylamine.

[0214]

[0215] <Molecular weight measurement>

[0216] Apparatus: Normal temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by SENSHU Scientific Co., Ltd.

[0217] Column: Column manufactured by Shodex Corporation (KD-803, KD-805).

[0218] Column temperature: 50℃.

[0219] Eluent: N,N-dimethylformamide (as additives, lithium bromide monohydrate (LiBr·H2O) is 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) is 30 mmol / L, and tetrahydrofuran (THF) is 10 mL / L), flow rate: 1.0 ml / min.

[0220] Standard samples for preparing the calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weight: about 900,000, 150,000, 100,000, 30,000); and polyethylene glycol manufactured by Polymer Laboratories (molecular weight: about 12,000, 4,000, 1,000).

[0221] <Measurement of Imidization Rate>

[0222] Add 20 mg of polyimide powder to an NMR sample tube (NMR standard sampling tube φ5 manufactured by Kusano Scientific Co., Ltd.), add 1.0 mL of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS mixture), and apply ultrasound to completely dissolve it. The solution was measured for 500 MHz proton NMR using an NMR measuring instrument (JNW-ECA500) manufactured by DATUM, Japan Electronics Co., Ltd. The imidization rate was determined as follows: the proton derived from the structure that did not change before and after imidization was determined as the reference proton, and the peak integral value of the proton derived from the NH group of the amic acid appearing near 9.5 to 10.0 ppm was used to determine the following formula.

[0223] In the following formula, x represents the peak integral value of protons derived from NH groups of amic acid, y represents the peak integral value of reference protons, and α represents the number ratio of reference protons to one proton of NH groups of amic acid in the case of polyamic acid (imidation ratio 0%).

[0224] Imidization rate (%) = (1-α·x / y) × 100

[0225] <Viscosity measurement>

[0226] The viscosity of the liquid crystal aligning agent was measured at a temperature of 25° C. using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample amount of 1.1 mL and a conical rotor TE-1 (1°34′, R24).

[0227] (Synthesis example 1)

[0228] BODA (15.0 g, 60.0 mmol), DBA (18.3 g, 120 mmol), 3AMPDA (21.8 g, 90.0 mmol) and DA-1 (34.3 g, 90.0 mmol) were dissolved in NMP (357 g), reacted at 60° C. for 3 hours, then PMDA (13.1 g, 60.0 mmol) was added, followed by CBDA (34.1 g, 174 mmol) and NMP (137 g), and reacted at 25° C. for 10 hours to obtain a polyamic acid solution.

[0229] NMP was added to the polyamic acid solution (500 g) and diluted to 6.5% by mass. Acetic anhydride (111 g) and pyridine (34.5 g) were added as imidization catalysts and reacted at 60° C. for 3 hours. The reaction solution was put into methanol (7000 mL) and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain a polyimide powder (A). The imidization rate of the polyimide was 80%, the number average molecular weight was 12,000, and the weight average molecular weight was 24,000.

[0230] (Synthesis example 2)

[0231] TCA (43.9 g, 196 mmol), DA-2 (30.3 g, 40.0 mmol), DA-4 (9.49 g, 40.0 mmol), DA-5 (13.9 g, 70.0 mmol), and DA-6 (16.5 g, 50.0 mmol) were mixed in NMP (455 g), and reacted at 60° C. for 15 hours to obtain a polyamic acid solution having a resin solid content concentration of 20% by mass.

[0232] NMP was added to the polyamic acid solution (100 g) and diluted to 6.5% by mass. Acetic anhydride (17.9 g) and pyridine (5.55 g) were added as imidization catalysts and reacted at 100 ° C for 3 hours. The reaction solution was put into methanol (1160 ml) and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 ° C to obtain a polyimide powder (B). The imidization rate of the polyimide was 72%, the number average molecular weight was 13300, and the weight average molecular weight was 40500.

[0233] (Synthesis example 3)

[0234] TDA (30.0 g, 100 mmol), PDA (9.73 g, 90 mmol), and DA-3 (3.77 g, 10.0 mmol) were dissolved in NMP (247 g), and the mixture was reacted at 40° C. for 3 hours to obtain a polyamic acid solution.

[0235] NMP was added to the polyamic acid solution (50 g) and diluted to 5% by mass. Acetic anhydride (17.6 g) and pyridine (8.20 g) were added as imidization catalysts and reacted at 40° C. for 3 hours. The reaction solution was put into methanol (600 ml) and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain a polyimide powder (C). The imidization rate of the polyimide was 85%, the number average molecular weight was 13400, and the weight average molecular weight was 27000.

[0236] (Synthesis Example 4)

[0237] 13DM-CBDA (17.1 g, 76.4 mmol), PDA (1.73 g, 16.0 mmol), DA-7 (5.86 g, 24.0 mmol), DA-8 (7.69 g, 24.0 mmol), and DA-9 (5.46 g, 16.0 mmol) were dissolved in NMP (277 g) and reacted at 50° C. for 15 hours to obtain a polyamic acid solution.

[0238] NMP was added to the polyamic acid solution (100 g) and diluted to 9% by mass. Acetic anhydride (7.60 g) and pyridine (0.98 g) were added as imidization catalysts and reacted at 55° C. for 3 hours. The reaction solution was put into methanol (530 ml) and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60° C. to obtain a polyimide powder (D). The imidization rate of the polyimide was 66%, the number average molecular weight was 14,300, and the weight average molecular weight was 35,800.

[0239] (Synthesis Example 5)

[0240] MA-1 (10.2 g, 20.0 mmol), MA-2 (2.61 g, 30.0 mmol), MA-3 (2.35 g, 16.5 mmol) and NMP (60.6 g) were added to a four-necked flask to completely dissolve the monomer components. The solution was degassed using a diaphragm pump, and AIBN (0.550 g, 3.33 mmol) was added as a polymerization initiator and degassed again. Thereafter, the mixture was reacted at 60°C for 13 hours to obtain a methacrylic acid polymer solution (E). The number average molecular weight of the polymer was 15,800, and the weight average molecular weight was 68,200.

[0241] (Example 1)

[0242] NMP (44.0 g) was added to the obtained polyimide powder (A) (6.00 g), and the mixture was stirred at 70° C. for 20 hours to dissolve. Me-3AMP (2 mass % NMP solution, 6.00 g) was added to the solution as an amine compound (B), and NMP (4.00 g) and BCS (40.0 g) were further added, and the mixture was stirred at room temperature for 3 hours to obtain a liquid crystal aligning agent (A1).

[0243] (Examples 2, 3 and Comparative Examples 1, 2)

[0244] Liquid crystal aligning agents (A2) to (A5) were prepared in the same manner as in Example 1 except that the kind of the amine compound (B) to be added was changed. The obtained liquid crystal aligning agents and the amine compound (B) used therein are shown in Table 1 below.

[0245] In addition, in Comparative Example 2, the amine compound (B) was not added.

[0246] [Table 1]

[0247]

[0248] <Storage stability test>

[0249] The liquid crystal aligning agents obtained in Examples 1 to 3 and Comparative Example 1 or 2 were placed in a vial and sealed, and allowed to stand at 25° C. in a light-shielding environment. Changes in the viscosity of the liquid crystal aligning agent during the standing and the molecular weight of the polyimide contained in the liquid crystal aligning agent were tracked.

[0250] Table 2 below shows a change in the viscosity of the liquid crystal aligning agent. Table 3 also shows a change in the molecular weight (number average molecular weight) of the polyimide contained in the liquid crystal aligning agent.

[0251] [Table 2]

[0252]

[0253] [Table 3]

[0254]

[0255] <Evaluation of whitening characteristics>

[0256] 0.1 mL of the liquid crystal aligning agent obtained in Examples 1 to 3 and Comparative Example 1 or 2 was dropped onto a chromium substrate and allowed to stand at 23° C. and 70% humidity. The edge and center of the droplet were observed with an optical microscope, and the time until precipitates were generated was measured.

[0257] It should be noted that in this evaluation, the phenomenon in which the dissolved polyimide precipitates or aggregates and the droplets become turbid is defined as a whitening phenomenon. The state in which the droplets are not completely whitened is evaluated as "0", the state in which only the edge of the droplets is whitened is evaluated as "△", and the state in which the entire surface of the droplets is whitened is evaluated as "×".

[0258] Table 4 shows the evaluation results of the whitening properties after 3 days of the above storage stability test of the liquid crystal aligning agent.

[0259] [Table 4]

[0260]

[0261] From the results of Tables 2 and 3, it is understood that, compared with the changes in viscosity and molecular weight in Comparative Example 1, the decreases in viscosity and molecular weight were significantly suppressed in Examples 1 to 3, and the storage stability of the polyimide varnish was improved.

[0262] Furthermore, as can be seen from the results of the whitening test in Table 4, Examples 1 to 3 have significantly improved whitening characteristics compared to Comparative Example 2.

[0263] Furthermore, from the results in Table 4, it can be seen that the whitening characteristics of Examples 1 to 3 are less likely to deteriorate than those of Comparative Example 1. This is probably because the aliphatic amine of 3AMP is a primary amine and therefore easily performs a nucleophilic attack on the polyimide main chain, whereas the nucleophilicity of secondary and tertiary amines to the polyimide main chain is suppressed due to the influence of steric hindrance.

[0264] (Examples 4 to 8, Comparative Examples 3 to 12, Synthesis Examples 6 to 8)

[0265] In Example 1, except having changed the polyimide powder, the amine compound, and the organic solvent as shown in the following Table 5, it carried out similarly, and prepared the liquid crystal aligning agents (B1)-(B2), (C1)-(C3), and (D1)-(D3).

[0266] In addition, NMP (24.0 g), BCS (40.0 g), and MBA (2 mass% NMP solution) 6.00 g were added to the methacrylic acid polymer solution (E) (30.0 g) obtained in Synthesis Example 5, and stirred at room temperature for 3 hours to obtain a liquid crystal aligning agent (E1) (Synthesis Example 6). Furthermore, in Synthesis Example 6, except that the amine compound was changed as shown in Table 5 below, liquid crystal aligning agents (E2) to (E3) (Synthesis Examples 7 and 8) were prepared in the same manner.

[0267] Table 5 shows the combination of each liquid crystal aligning agent and the additive used therein.

[0268] [Table 5]

[0269]

[0270] Next, mixing of the liquid crystal aligning agents (B1) to (B3), (E1) to (E3) obtained so far and the liquid crystal aligning agents (A2), (A4), and (A5) is carried out.

[0271] Table 6 shows the combination of the mixed liquid crystal aligning agents and the combination of the additives contained in the liquid crystal aligning agent.

[0272] [Table 6]

[0273]

[0274] The storage stability test and the evaluation of the whitening property were performed similarly to the above about the liquid crystal aligning agent obtained above. The results are shown in Tables 7 to 10 below.

[0275] <Storage stability test>

[0276] [Table 7]

[0277]

[0278] [Table 8]

[0279]

[0280] <Evaluation of whitening characteristics>

[0281] Table 9 shows the evaluation results carried out on the preparation day of the liquid crystal aligning agent, and Tables 9 and 10 show the evaluation results after 3 days of the above-mentioned storage stability test.

[0282] [Table 9]

[0283]

[0284] [Table 10]

[0285]

[0286] From the results of Tables 7 and 8, it is understood that in Examples 5 to 8, decreases in viscosity and molecular weight can be significantly suppressed, and storage stability is improved.

[0287] Furthermore, from the results of the whitening tests in Tables 9 and 10, it can be seen that Examples 5 to 8 have significantly improved whitening characteristics compared to Comparative Examples 5 to 12.

[0288] Industrial Applicability

[0289] The polyimide varnish of the present invention is widely used in a wide range of fields such as a liquid crystal aligning agent for forming a liquid crystal aligning film in a liquid crystal display element, and particularly a film-shaped protective material and an insulating material in the electrical and electronic fields including an insulating film for semiconductors.

[0290] It should be noted that all the contents of the specification, claims, and abstract of Japanese Patent Application No. 2020-30729 filed on February 26, 2020 are incorporated herein by reference and incorporated as a disclosure of the specification of the present invention.

Claims

1. A polyimide varnish, characterized in that: Contains the following components (A) and (B), (A) component: polyimide (A) which is an imide product of a polyimide precursor, Component (B): an amine compound (B) having in the molecule a secondary amino group or a tertiary amino group and a nitrogen-containing aromatic heterocyclic group or a cyclic group of an aromatic hydrocarbon group, wherein the amino group is bonded to a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group, The amine compound (B) is represented by the following formula (1): In formula (1), R1 and R2 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, at least one of R1 and R2 represents an alkyl group having 1 to 5 carbon atoms, Ar represents a nitrogen-containing aromatic heterocyclic ring or an aromatic hydrocarbon group, X represents a divalent organic group containing a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group, and the N to which R1 and R2 are bonded is bonded to the non-cyclic aliphatic hydrocarbon group or the non-aromatic cyclic hydrocarbon group. The polyimide precursor of the polyimide (A) is obtained using a tetracarboxylic acid component containing tetracarboxylic dianhydride represented by the following formula (3) or a derivative thereof. In formula (3), X represents a structure selected from the group consisting of the following (x-1) to (x-11), In the (x-1)~(x-11) structures, R 1 ~R 4 each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom, a fluorine atom, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group, and R 5 and R 6 Each independently represents a hydrogen atom or a methyl group, *1 is a bond to one acid anhydride group, and *2 is a bond to another acid anhydride group.

2. The polyimide varnish according to claim 1, wherein The amine compound (B) is a compound wherein X in the formula (1) is represented by *1-X1-X2-*2, In this compound, X1 represents a divalent organic group including a non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group having 1 to 10 carbon atoms, X2 represents a single bond, -O-, -NH-, -S-, -SO2- or a divalent organic group having 1 to 19 carbon atoms, and the total number of carbon atoms possessed by X1 and X2 is 1 to 20, *1 is a bond bonded to N of formula (1), and *2 is a bond bonded to Ar of formula (1).

3. The polyimide varnish according to claim 2, wherein In the above-X1-X2-, X1 is a divalent non-cyclic aliphatic hydrocarbon group or a non-aromatic cyclic hydrocarbon group having 1 to 10 carbon atoms.

4. The polyimide varnish according to any one of claims 1 to 3, wherein The amine compound (B) is one or more compounds represented by any of the following formulas (b-1) to (b-14), 5. The polyimide varnish according to claim 1, wherein The tetracarboxylic dianhydride or its derivative represented by the formula (3) is a tetracarboxylic dianhydride or its derivative wherein X is (x-1) to (x-7) or (x-11).

6. The polyimide varnish according to any one of claims 1 to 3, wherein The polyimide precursor of the polyimide (A) is obtained by using a diamine having a side chain structure represented by the following formulae (S1) to (S3), In formula (S1), X 1 and X 2 Each independently represents a single bond, -(CH2) a -, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 -, a is an integer of 1 to 15, wherein a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, m1 is 1 to 2, G 1 and G 2 Each independently represents a divalent cyclic group of a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms, any hydrogen atom on the cyclic group is optionally substituted, m and n are each independently an integer of 0 to 3, m+n is 1 to 6, R 1 represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms, forming R 1 Any hydrogen atom of X is optionally substituted by a fluorine atom. 1 , X 2 , G 1 , G 2 When there are two or more a1 and A1, two or more X 1 , X 2 , G 1 , G 2 , a1 and A1 are independently and optionally the same or different, -X 3 -R 2 (S2) In formula (S2), X 3 represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -COO- or -OCO-, R 2 represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, forming R 2 Any hydrogen atom of is optionally substituted by a fluorine atom, -X 4 -R 3 (S3) In formula (S3), X 4 Indicates -CONH-, -NHCO-, -O-, -CH2O-, -OCH2-, -COO- or -OCO-, R 3 Represents a structure having a steroid skeleton.

7. The polyimide varnish according to claim 6, wherein The diamine is at least one diamine selected from the group consisting of the following formulae (V-1) to (V-13), In the above formulas (V-1) to (V-13), X v1 ~X v4 , X p1 ~X p8 Each independently represents -(CH2) a -, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-, a is an integer of 1 to 15, X v5 Indicates -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-, X V6 ~X V7 , X s1 ~X s4 Each independently represents -O-, -CH2O-, -OCH2-, -COO- or -OCO-, X a ~X f Each independently represents a single bond, -O-, -NH-, -O-(CH2) m -O-, -C(CH3)2-, -CO-, -COO-, -CONH-, -(CH2) m -, -SO2-, -O-C(CH3)2-, -CO-(CH2) m -, -NH-(CH2) m -, -NH-(CH2) m -NH-, -SO2-(CH2) m -、-SO2-(CH2) m -SO2-, -CONH-(CH2) m -、-CONH-(CH2) m -NHCO-, or -COO-(CH2) m -OCO-,R v1 ~R v4 , R 1a ~R 1h Each independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms; and m represents an integer of 1 to 8.

8. The polyimide varnish according to any one of claims 1 to 3, wherein The polyimide (A) has a structure in which 20% to 90% of all repeating units of a polyimide precursor are ring-closed.

9. The polyimide varnish according to any one of claims 1 to 3, wherein The amine compound (B) is contained in a ratio of 0.1 to 50 parts by mass relative to 100 parts by mass of the polyimide (A). 10 . A liquid crystal aligning agent obtained from the polyimide varnish according to claim 1 .

11. The liquid crystal alignment agent according to claim 10, wherein: The liquid crystal aligning agent further contains at least one other polymer selected from the group consisting of a polyimide precursor, polysiloxane, polyester, polyamide, polyurea, polyorganosiloxane, a cellulose derivative, polyacetal, and a polymerizable unsaturated bond-containing monomer polymer.

12. The liquid crystal alignment agent according to claim 11, wherein The polymer of the monomer having a polymerizable unsaturated bond is obtained using at least one compound selected from the group consisting of (meth)acrylic acid compounds, (meth)acrylamide compounds, aromatic vinyl compounds, conjugated diene compounds, maleimide group-containing compounds, α-methylene-γ-butyrolactone compounds, vinyl compounds other than aromatic vinyl compounds, and compounds containing a maleic anhydride structure.

13. The liquid crystal aligning agent according to claim 11 or 12, wherein: The polymer of the monomer having a polymerizable unsaturated bond is obtained using at least one monomer selected from the group consisting of a monomer represented by the following formula (S-mA), a monomer having a carboxyl group and a polymerizable unsaturated bond, and a monomer having an epoxy skeleton and a polymerizable unsaturated bond. PXJ (S-mA) In the formula (S-mA), P represents a (meth)acryloyloxy group, a styryl group, a vinyloxy group CH2=CH-O-, a maleimide group, or an α-methylene-γ-butyrolactone structure. X represents a single bond, -(CH2) a -, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 - or a group "-L-OCO-CR'=CR"-", a is an integer of 1 to 15, a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, m1 is an integer of 1 to 2, and when m1 is 2, a1 and A1 each independently have the above definition, wherein when P is a (meth)acryloyloxy group, a vinyloxy group CH2=CH-O-, or a maleimide group, X represents a single bond or a linking group bonded to P via a carbon atom, J represents a monovalent organic group having at least one group selected from the group consisting of an alicyclic hydrocarbon group having 4 to 40 carbon atoms and an aromatic hydrocarbon group having 6 to 40 carbon atoms, wherein at least one of the hydrogen atoms possessed by the alicyclic hydrocarbon group and the aromatic hydrocarbon group is substituted with a substituent selected from the group consisting of a halogen atom, an alkyl group containing a halogen atom, an alkoxy group containing a halogen atom, an alkyl group containing 3 to 10 carbon atoms, an alkoxy group containing 3 to 10 carbon atoms, an alkenyl group containing 3 to 10 carbon atoms, and a heteroatom-containing group in which the carbon-carbon bond possessed by any methylene group of the alkyl group containing a halogen atom, the alkoxy group containing a halogen atom, the alkyl group, the alkoxy group, and the alkenyl group is interrupted by an oxygen atom, In the group "-L-OCO-CR'=CR"-", L represents a single bond or -(B1-(CH2) b1 ) m’ -, b1 is an integer of 1 to 15, B1 represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO- or -OCO-, m' is an integer of 1 to 2, when m' is 2, a plurality of b1 and B1 each independently have the above definition, at least one B1 represents a linking group other than a single bond, and R', R" represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 14 . A liquid crystal alignment film formed using the liquid crystal aligning agent according to claim 10 . 15 . A liquid crystal display element comprising the liquid crystal alignment film according to claim 14 .

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