JP6686298B2 - Liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display device.

  Conventionally, as a liquid crystal display element, various driving methods having different electrode structures and physical properties of liquid crystal molecules to be used have been developed. For example, TN (Twisted Nematic) type, STN type, VA (Vertical Alignment) type, MVA type Various in-plane switching type (IPS type), FFS (Fringe Field Switching) type, optical compensation bend type (OCB type) liquid crystal display elements are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polymers such as polyamic acid, polyimide, polyamic acid ester, polyamide, polyester and polyorganosiloxane are used. Among them, various properties such as heat resistance, mechanical strength and affinity with liquid crystal are used. Polyamic acid and polyimide are generally used because of their good properties.

  In recent years, liquid crystal panels have been used not only in display devices such as personal computers as in the past, but also in various applications such as liquid crystal televisions, car navigation systems, mobile phones, smartphones, and information displays. One of the important characteristics of a liquid crystal panel is high reliability with little deterioration in quality due to use, and various liquid crystal aligning agents have been proposed to satisfy this characteristic (for example, refer to Patent Document 1).

  In Patent Document 1, an aromatic diamine in which an amino group protected by a tertiary butoxycarbonyl group (t-BOC group) is introduced at the ortho position with respect to the primary amino group is used, and obtained using this diamine. It has been proposed that the liquid crystal aligning agent contains a polyamic acid or polyimide. According to this technique, the t-BOC group is deprotected by heating during film formation to generate an amino group, and the reliability is improved by an intramolecular reaction or an intermolecular reaction (crosslinking reaction) of the generated amino group. It is described in Patent Document 1.

International Publication No. 2013/115228

  The technique described in Patent Document 1 is a technique that utilizes an amino group generated by heating during film formation, and it is considered that the reliability of the liquid crystal panel cannot be sufficiently improved because the crosslinking reaction is difficult to proceed.

  Further, when a thermally decomposable monomer is used, if a large amount of unreacted functional groups remain after heating, it is conceivable that bubbles may be generated in the liquid crystal panel during long-term lighting. In order to suppress the occurrence of such an inconvenience, it is required that the outgas from the liquid crystal alignment film is small after post-baking.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a highly reliable liquid crystal display device with a small amount of outgas from a liquid crystal aligning film.

  The inventors of the present invention have made earnest studies to achieve the above-mentioned problems of the prior art, and have attempted to introduce a specific structure considered to exhibit thermal decomposability into a polymer. Then, they have found that the above problems can be solved by using a polymer having this specific structure as a polymer component of a liquid crystal aligning agent, and have completed the present invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display device.

  In one aspect, the present invention contains at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyamide, and at least a part of the polymer is represented by the following formula (1). Provided is a liquid crystal aligning agent which is a polymer (P) having a partial structure.

(In formula (1), A ¹ and A ² are each independently a hydrogen atom or a monovalent organic group, and the total number of carbon atoms of A ¹ and A ² is 0 to 7. Y ¹ is an oxygen atom. Or a sulfur atom, R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, X ¹ is a single bond or a divalent organic group, and “*” represents a bond. )

  The present invention, in another aspect, provides a liquid crystal alignment film formed using the above liquid crystal alignment agent, and a liquid crystal display device including the liquid crystal alignment film.

  With the liquid crystal aligning agent containing the polymer (P), a liquid crystal aligning film with a small outgas amount can be formed. Further, since the liquid crystal display device of the present invention has the liquid crystal alignment film formed by using the liquid crystal alignment agent containing the above-mentioned polymer (P), the quality deterioration due to use is little and the reliability is excellent.

The figure which shows the electrode pattern of the transparent electrode film used in the Example and the comparative example. The figure which shows the electrode pattern of the transparent electrode film used in the Example. The figure which shows the electrode pattern of the transparent electrode film used in the Example.

  Each component contained in the liquid crystal aligning agent and other components optionally blended as necessary will be described below.

<Polymer (P)>
The liquid crystal aligning agent according to the present invention has, as a polymer component, at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyamide as a main skeleton, and a partial structure represented by the following formula (1). The polymer (P) having
(In formula (1), A ¹ and A ² are each independently a hydrogen atom or a monovalent organic group. However, the total number of carbon atoms of A ¹ and A ² is 0 to 7. Y ¹ is An oxygen atom or a sulfur atom, R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, X ¹ is a single bond or a divalent organic group, and “*” is a bond. Show.)

In the above formula (1), examples of the monovalent organic group of A ¹ and A ² include a monovalent hydrocarbon group; a methylene group of a monovalent hydrocarbon group is —O—, —S—, —CO—. , -COO-, -COS-, and other groups substituted with a divalent heteroatom-containing group; at least one hydrogen atom of the monovalent hydrocarbon group is a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine). Groups substituted with atoms etc .; monovalent groups having a heterocycle, and the like. A ¹ and the carbon number of ^{A 2} is, ^{A 1} and is the total number of carbon atoms of ^{A 2} is not any is particularly limited in the range of 0 to 7, post-baking desorbed group "-CHA ¹ A by heating in the From the viewpoint of reducing the amount of the compound derived from " ² " remaining in the alignment film, it is preferably 0 to 6, more preferably 0 to 4, and further preferably 0 to 3.

  Here, in the present specification, the “hydrocarbon group” is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The “chain hydrocarbon group” means a straight chain hydrocarbon group or a branched chain hydrocarbon group which does not include a cyclic structure in the main chain and is composed of only a chain structure. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it does not need to be composed only of an alicyclic hydrocarbon structure, and may include a part of which has a chain structure. The “aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, the structure need not be composed of only the aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

Specific examples of the monovalent hydrocarbon group include chain hydrocarbon groups such as alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, and heptyl group: ethenyl group, propenyl group. And alkenyl groups such as butenyl group; alkynyl groups such as ethynyl group and propynyl group; and the like, which may be linear or branched. Further, examples of the alicyclic hydrocarbon group include a cyclohexyl group and a methylcyclohexyl group, and examples of the aromatic hydrocarbon group include a phenyl group and a tolyl group.
As A ¹ and A ² , a hydrogen atom, or a substituted or unsubstituted monovalent chain hydrocarbon group is preferable from the viewpoint of ease of elimination of the group “—CHA ¹ A ² ” by heating. More preferably, it is a hydrogen atom, or a substituted or unsubstituted alkyl group. In addition, A ¹ and A ² may be the same as or different from each other.

Examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms of R ¹ include an alkyl group having 1 to 6 carbon atoms, an alkenyl group, an alkynyl group, a cyclohexyl group, a phenyl group and the like. Specific examples of the alkyl group, the alkenyl group and the alkynyl group include those having 1 to 6 carbon atoms among the groups exemplified in A ¹ and A ² . R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Examples of the divalent organic group for X ¹ include a divalent hydrocarbon group; a methylene group of a divalent hydrocarbon group, -O-, -S-, -CO-, -COO-, -COS-,-. A group substituted with a divalent heteroatom-containing group such as NR ³ —, —CONR ³ — (wherein R ³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms); Examples thereof include a group in which at least one hydrogen atom of a hydrocarbon group is substituted with a halogen atom or the like; a divalent group having a heterocycle, and the like.
Specific examples of the divalent hydrocarbon group include chain hydrocarbon groups such as methylene group, ethylene group, propanediyl group, butanediyl group, pentanediyl group, and alkanediyl group such as hexanediyl group. These may be linear or branched. Further, examples of the alicyclic hydrocarbon group include a cyclohexylene group and the like; examples of the aromatic hydrocarbon group include a phenylene group, a biphenylene group, a naphthalene group and the like.
X ¹ is preferably a single bond or a substituted or unsubstituted divalent chain hydrocarbon group, and more preferably a single bond or a substituted or unsubstituted alkanediyl group.

“*” In formula (1) is preferably bonded to an aromatic ring. Examples of the aromatic ring to which “*” in formula (1) is bonded include a benzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, an imidazole ring, a thiol ring and the like. Preferred is a benzene ring, naphthalene ring or pyridine ring.
Y ¹ is preferably an oxygen atom from the viewpoint of easy synthesis of the compound.

  The polyamic acid, polyamic acid ester, polyimide and polyamide as the polymer (P) can be synthesized by a conventionally known method. As a specific example, tetracarboxylic acid dianhydride, tetracarboxylic acid diester, at least one carboxylic acid derivative selected from the group consisting of tetracarboxylic acid diester dihalide and dicarboxylic acid, and a polymer using a raw material containing a diamine Examples include a method of synthesizing (P).

[Polyamic acid]
The polyamic acid as the polymer (P) can be obtained, for example, by reacting a tetracarboxylic dianhydride and a diamine. As a specific method, [1] a method of synthesizing by tetrapolymeric dianhydride having a structure represented by the above formula (1) by polymerization containing a raw material composition, [2] represented by the above formula (1) A method of synthesizing a diamine having a structure having a structure represented by the formula: [3] a tetracarboxylic dianhydride having a structure represented by the above formula (1) and a structure represented by the above formula (1) A method in which diamine is included in the raw material composition for synthesis, and the like can be mentioned. Of these, the method [2] is preferable because there are few restrictions on the monomer.

(Tetracarboxylic acid dianhydride)
Examples of the tetracarboxylic acid dianhydride used in the synthesis of the polyamic acid include, for example, aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, and aromatic tetracarboxylic acid dianhydride. it can. Specific examples of these are:
As the aliphatic tetracarboxylic dianhydride, for example, 1,2,3,4-butanetetracarboxylic dianhydride and the like;
Examples of the alicyclic tetracarboxylic acid dianhydride include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4. 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- No 1,2-dicarboxylic acid 1,3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 4,6: 8 dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10- tetraone, cyclohexane tetracarboxylic acid dianhydride , Cyclopentanetetracarboxylic dianhydride and the like;
Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride;
Other than these, the tetracarboxylic dianhydride described in JP 2010-97188 A and the like can be used. In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

The tetracarboxylic acid dianhydride used for the synthesis of the polyamic acid preferably contains an alicyclic tetracarboxylic acid dianhydride in terms of good solubility and transparency in a solvent. Among them, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 1,2,4. At least selected from the group consisting of 5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride Better to include one Specifically, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 1, From the group consisting of 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 1,2,3,4-cyclopentanetetracarboxylic dianhydride It is more preferable to contain at least one selected compound (hereinafter, also referred to as “specific tetracarboxylic acid dianhydride”).
As the tetracarboxylic dianhydride used for the synthesis of the polyamic acid, the above-mentioned specific tetracarboxylic dianhydride should be 20 mol% or more based on the total amount of the tetracarboxylic dianhydride used for the synthesis. Are preferred, those containing 40 mol% or more are more preferred, and those containing 60 mol% or more are even more preferred.

(Diamine)
The diamine used for synthesizing the polyamic acid preferably contains a compound having the structure represented by the above formula (1) and two primary amino groups (hereinafter also referred to as “specific diamine”).

Specific examples of the specific diamine include compounds represented by the following formula (c).
(In the formula (c), B ¹ is a divalent organic group having a partial structure represented by the above formula (1), and B ² and B ³ are each independently a hydrogen atom or the above formula (1). Is a monovalent organic group having a partial structure represented by, Z ¹ and Z ² are each independently a single bond or a divalent linking group, and R ⁵ and R ⁶ are each independently a halogen atom or It is a monovalent hydrocarbon group having 1 to 6 carbon atoms, n1 and n2 are each independently an integer of 0 to 2, and m1 and m2 are each independently 0 or 1, provided that m1 = 1. In the case of, B ² has a partial structure represented by the above formula (1), and when m1 = 0 and m2 = 0, at least one of B ² and B ³ is represented by the above formula (1). has a partial structure that, in the case of m1 = 0 and m @ 2 = ^1, Sukunakutomoizu of B 1, ^{B 2} and ^{B 3} Or has the partial structure represented by the above formula (1).)

In the above formula (c), specific examples of B ¹ include, for example, a group represented by the following formula (b-1).
(In the formula (b-1), R ⁴ is a nitrogen atom or a trivalent hydrocarbon group. A ¹ , A ² , Y ¹ , R ¹ and X ¹ are each synonymous with the above formula (1). Yes, "*" indicates a bond.)

In the above formula (b-1), the trivalent hydrocarbon group of R ⁴ is preferably an aromatic ring group.
The monovalent organic group of B ² and B ³ may be a group having at least one partial structure represented by the above formula (1). Preferably, it is a monovalent group represented by the above formula (1).
The divalent linking group for Z ¹ and Z ² is —O—, —NH—, an alkanediyl group having 1 to 10 carbon atoms, or one or more methylene groups having 1 to 10 carbon atoms. It is preferably a divalent group substituted with O-.
0 or 1 is preferable and, as for n1 and n2, 0 is more preferable.

Specific preferred examples of the specific diamine include compounds represented by the following formula (d).
(In the above formula (d), R ⁷ is a halogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, and n 3 is an integer of 0 to ^2. A ¹ , A ² , Y ¹ , and R. ¹ and X ¹ are respectively synonymous with the above formula (1).)

In the above formula (d), the description of the above formula (1) can be applied to the examples and preferable specific examples of A ¹ , A ² , Y ¹ , R ¹ and X ¹ .
In the formula (d), the bonding positions of the two primary amino groups in the diaminophenyl group are 2,4-position, 2,5-position, and 3-position with respect to the group represented by the formula (1). , 5-position and the like, but from the viewpoint of high reliability improving effect, 3,5-position is preferable.
n3 is preferably 0 or 1, and more preferably 0.

Moreover, the compound represented by following formula (e) is mentioned as a preferable specific example of a specific diamine.
(In formula (e), Z ³ is a single bond or a divalent linking group, V ¹ is a hydrogen atom or a monovalent group represented by the above formula (1), and R ⁸ and R ⁹ are , Each independently a halogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, n4 and n5 each independently represent an integer of 0 to ^2. A ¹ , A ² , Y ¹ , R ¹ and X ¹ has the same meaning as in the above formula (1).)

In the above formula (e), the description of the above formula (1) can be applied to the examples and preferred specific examples of A ¹ , A ² , Y ¹ , R ¹ and X ¹ . Z ³ is preferably a divalent linking group, and the preferred examples of Z ¹ and Z ^{2 in} the above formula (c) can be applied to the specific examples thereof.
n4 and n5 are preferably 0 or 1, and more preferably 0.

Specific examples of the specific diamine include compounds represented by the following formulas (MDA-1) to (MDA-21).

  In addition, a specific diamine can be used individually by 1 type or in combination of 2 or more types. Hereinafter, the compound represented by the formula (MDA-X) may be referred to as "compound (MDA-X)".

The diamine used for synthesizing the polyamic acid may be only the specific diamine, or other diamine may be used together with the specific diamine. Examples of other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples of these include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine.
Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;

As the aromatic diamine, for example, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 2,2'-bis (trifluoromethyl) -4,4 '-Diaminobiphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) Phenyl] hexafluoropropane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophen) Noxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, N, N′-bis (4-aminophenyl) -benzidine, 1- (4-aminophenyl) -2 , 3-Dihydro-1,3,3-trimethyl-1H-indene-5-amine, 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6- Amine, 3,5-diaminobenzoic acid, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4 -Diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostanyl 3,5-diaminobenzoate 3, -Bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4'-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1- Bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 2,4-diamino-N, N-diallylaniline, 4-aminobenzylamine, and the following formula (D-1)
(In Formula (D-1), X ^I and X ^II are each independently a single bond, —O—, —COO—, or —OCO—, and R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and n is It is 0 or 1. However, a and b cannot be 0 at the same time.)
A compound represented by

  Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and diamines described in JP 2010-97188 A can be used.

In the above formula (D-1) ^{"-X I - (R I -X II} ) n - " Examples of the divalent group represented by the alkanediyl group having 1 to 3 carbon atoms, * - O -, * It is preferably —COO— or * —O—C ₂ H ₄ —O— (however, the bond marked with “*” bonds to the diaminophenyl group). Specific examples of the group “—C _c H _{2c + 1} ” include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group. , N-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group , N-eicosyl group and the like. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or the 3,5-position with respect to the other groups.

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

As the other diamine, in addition to the two primary amino groups, at least one structure selected from the group consisting of a nitrogen-containing heterocycle, a secondary amino group and a tertiary amino group (hereinafter also referred to as "nitrogen-containing structure"). .) And the like. By using a diamine having such a nitrogen-containing structure as a raw material, a polymer having a corresponding nitrogen-containing structure and the structure represented by the above formula (1) can be obtained. Such a polymer is preferable because the effect of improving the reliability of the liquid crystal display device can be enhanced.
Specific examples of the diamine having a nitrogen-containing structure include, for example, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diamino. Examples include carbazole, 1,4-bis- (4-aminophenyl) -piperazine, compounds represented by the following formulas (D-2-1) to (D-2-6), and the like.

As the diamine used in the synthesis of the polyamic acid, the mixing ratio of the specific diamine is preferably 1 mol% or more, more preferably 3 mol% or more, and more preferably 5 mol% with respect to the total amount of the diamine. It is more preferable that the amount is above, and it is particularly preferable that the amount is 10 mol% or more. The upper limit of the use ratio of the specific diamine is not particularly limited, but it is preferably 90 mol% or less, and 80 mol% or less from the viewpoint of enhancing various properties such as liquid crystal orientation and electric properties with other diamines. Is more preferable, and 70 mol% or less is further preferable.
The use ratio of the diamine having a nitrogen-containing structure is preferably 0.1 mol% or more, more preferably 1 mol% or more, more preferably 2 mol% or more, based on the total amount of diamine used in the synthesis. More preferably, The use ratio of the diamine having a nitrogen-containing structure is preferably 60 mol% or less, more preferably 50 mol% or less, and further preferably 40 mol% or less.
In addition, as other diamine, 1 type can be used individually or in combination of 2 or more types.

(Synthesis of specific diamine)
The specific diamine can be synthesized by appropriately combining known methods. As an example thereof, for example, a dinitro intermediate having a nitro group in place of the primary amino group in a specific diamine is synthesized, and then the nitro group of the obtained dinitro intermediate is aminated using a suitable reducing system. Method etc. are mentioned. The method for synthesizing the dinitro intermediate can be appropriately selected depending on the target compound. For example, a method of reacting dinitroaniline with an alkyl chloroformic acid, a method of reacting dinitrobenzoic acid chloride with a hydroxyl group-containing compound having a structure represented by the above formula (1), an isocyanate group-containing dinitrophenyl isocyanate, etc. Examples thereof include a method of reacting a compound with a compound having a group “—CHA ¹ A ² ” and a hydroxyl group.

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the above-mentioned tetracarboxylic dianhydride and diamine together with a molecular weight modifier, if necessary. The ratio of the tetracarboxylic dianhydride and the diamine used for the synthesis reaction of the polyamic acid is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 with respect to 1 equivalent of the amino group of the diamine. The equivalent ratio is preferable, and the 0.3-1.2 equivalent ratio is more preferable.
Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Can be mentioned. The proportion of the molecular weight modifier used is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less, based on 100 parts by weight of the total tetracarboxylic dianhydride and diamine used.

  The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

  Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (organic solvent of the first group), or one or more selected from the organic solvent of the first group. And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (organic solvent of the second group). In the latter case, the use ratio of the second group organic solvent is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. It is below, and more preferably 30% by weight or less.

  Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. It is preferable to use one or more selected from the group consisting of and halogenated phenols as a solvent, or to use a mixture of one or more of these with other organic solvents in the range of the above ratio. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine becomes 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. Is good

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be directly subjected to the next step, may be subjected to the next step after isolating the polyamic acid, or may be subjected to the next step after purifying the isolated polyamic acid. Good. These purification operations can be performed according to known methods.

[Polyamic acid ester]
The polyamic acid ester is, for example, [I] a method of reacting the polyamic acid obtained by the above synthetic reaction with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, [III] tetracarboxylic acid. It can be obtained by a method of reacting a diester dihalide with a diamine, or the like.

  Here, examples of the esterifying agent used in the method [I] include a hydroxyl group-containing compound, an acetal compound, a halide, and an epoxy group-containing compound. Specific examples thereof include hydroxyl group-containing compounds such as alcohols such as methanol, ethanol and propanol, phenols such as phenol and cresol, and the like; acetal compounds such as N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethylacetal and the like; halides such as methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride and 1,1,1-trifluoro-2-iodoethane; epoxy group-containing Examples of the compound include propylene oxide and the like.

The tetracarboxylic acid diester used in the method [II] can be obtained by ring-opening a tetracarboxylic acid dianhydride using the above alcohols. The tetracarboxylic acid diester dihalide used in the method [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. When obtaining a polyamic acid ester having a partial structure represented by the above formula (1), in the methods [II] and [III], the structure represented by the above formula (1) is used as at least a part of the diamine used in the reaction. A polyamic acid ester having a partial structure represented by the above formula (1) can be obtained by using a diamine having The polyamic acid ester may have only an amic acid ester structure, or may be a partial esterified product in which an amic acid structure and an amic acid ester structure coexist.
The reaction solution obtained by dissolving the polyamic acid ester may be directly subjected to the next step, may be subjected to the next step after isolating the polyamic acid ester, or the isolated polyamic acid ester is purified. Alternatively, it may be subjected to the next step. These purification operations can be performed according to known methods.

[Polyimide]
The polyimide as the polymer (P) can be obtained by subjecting the polyamic acid synthesized as described above to dehydration ring closure to imidize.

  Polyimide may be a completely imidized product obtained by dehydration ring closure of all of the amic acid structure of the precursor polyamic acid, dehydration ring closure of only a portion of the amic acid structure, the amic acid structure and imide It may be a partial imidized product having a ring structure. The imidation ratio of the polyimide is preferably 30% or more, more preferably 50 to 99%, further preferably 60 to 99%. This imidization ratio is a percentage of the ratio of the number of imide ring structures to the total number of amic acid structures and imide ring structures of polyimide. Here, a part of the imide ring may be an isoimide ring.

  The dehydration ring closure of the polyamic acid is preferably carried out by a method of heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, and by adding a dehydrating agent and a dehydration ring-closing catalyst to the solution and heating as necessary. . Of these, the latter method is preferable.

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

  In this way, a reaction solution containing polyimide is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution. The alignment agent may be prepared, or the isolated polyimide may be purified and then used to prepare the liquid crystal alignment agent. These purification operations can be performed according to known methods. The method for synthesizing the polyimide is not limited to the above, and for example, imidization of polyamic acid ester may be performed.

[polyamide]
The polyamide as the polymer (P) can be obtained, for example, by reacting a dicarboxylic acid with a diamine. Examples of the dicarboxylic acid used in the reaction include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, phthalic acid, isophthalic acid, terephthalic acid, and 5-decanooxyisophthalic acid. . The dicarboxylic acids may be used alone or in combination of two or more selected from these. As the diamine used in the reaction, the specific diamine may be used alone, or other diamine may be used together with the specific diamine.

  The reaction of dicarboxylic acid and diamine is preferably carried out in a suitable organic solvent. At this time, the dicarboxylic acid may be converted to an acid chloride and then reacted with a diamine. The reaction temperature can be preferably -100 to 200 ° C, more preferably -20 to 150 ° C. When the dicarboxylic acid is used as it is for reaction with the diamine, the reaction temperature is preferably room temperature (25 ° C.) or higher, and when the dicarboxylic acid is converted to acid chloride and then reacted with the diamine, The reaction temperature is preferably lower than room temperature. The reaction time is preferably 0.1 to 40 hours, more preferably 0.5 to 20 hours.

The polyamic acid, polyamic acid ester, polyimide and polyamide as the polymer (P) obtained as described above have a solution viscosity of 10 to 800 mPa · s when this is made into a solution having a concentration of 10% by weight. Is preferable, and one having a solution viscosity of 15 to 500 mPa · s is more preferable. The solution viscosity (mPa · s) of the polymer (P) is 10% by weight prepared using a good solvent for the polymer (P) (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using an E-type rotational viscometer for the polymer solution.
The polystyrene equivalent weight average molecular weight of the polymer (P) measured by gel permeation chromatography (GPC) is preferably 500 to 100,000, more preferably 1,000 to 50,000. .

Although not limiting the present invention, in the liquid crystal aligning agent containing the polymer (P) having the structure represented by the above formula (1), the above formula by heating (post-baking) during coating film formation. The group “—CHA ¹ A ² ” in the structure represented by (1) is eliminated to regenerate the isocyanate group, and between the regenerated isocyanate group and the carboxyl group, hydroxy group, amino group or the like in the system. It is presumed that the cross-linking reaction will proceed sufficiently with. It is presumed that such intermolecular or intramolecular cross-linking reaction is unlikely to cause deterioration of various properties due to use, and as a result, a liquid crystal display device having good reliability was obtained.

<Other ingredients>
The liquid crystal aligning agent may contain other components other than the polymer (P), if necessary. Examples of such other components include other polymers other than the polymer (P), compounds having at least one epoxy group in the molecule (hereinafter referred to as "epoxy group-containing compound"), functional silane compounds, and the like. Can be mentioned.

[Other polymers]
The above-mentioned other polymers can be used for improving solution properties and electric properties. Examples of such other polymer include polyamic acid having no partial structure represented by the above formula (1), polyimide having no partial structure represented by the above formula (1), and the above formula (1). Polyamic acid ester having no partial structure represented, polyamide having no partial structure represented by the above formula (1), polyorganosiloxane, polyester, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) ) Derivatives, poly (meth) acrylates, and the like.
When the other polymer is blended in the liquid crystal aligning agent, the blending ratio thereof is preferably 50% by weight or less, more preferably 0.1 to 40% by weight, based on the total amount of the polymer in the composition. 1 to 30% by weight is more preferable.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesiveness of the liquid crystal alignment film to the substrate surface and the electrical characteristics. Here, as the epoxy group-containing compound, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ', N'-tetraglycidyl-m-xylenediamine 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodi Enirumetan, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. In addition, as an example of the epoxy group-containing compound, the epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can also be used.
When these epoxy group-containing compounds are compounded in the liquid crystal aligning agent, the compounding ratio is preferably 40 parts by weight or less, and 0.1 to 30 parts by weight, based on 100 parts by weight of the total amount of the polymers contained in the liquid crystal aligning agent. Is more preferable.

[Functional silane compound]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such a functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3, 6- Methyl azanonanate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid Xypropyltrimethoxysilane etc. can be mentioned.
When these functional silane compounds are added to the liquid crystal aligning agent, the mixing ratio is preferably 2 parts by weight or less, and more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the total amount of the polymer.

  In addition, as the other components, additives other than the above may be appropriately blended within a range that does not impair the objects and effects of the present invention. Specific examples of the additives other than the above include, for example, a compound having at least one oxetanyl group in the molecule, an antioxidant, a surfactant, a defoaming agent, a sensitizer, a dispersant, an adhesion aid, an antistatic agent. , Leveling agents, antibacterial agents and the like.

[solvent]
The liquid crystal aligning agent according to the present invention is prepared as a liquid composition in which the polymer (P) and other components used as necessary are dispersed or dissolved in a suitable organic solvent.

  Examples of the organic solvent used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether , Ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol Recall diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. be able to. These may be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferably It is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the surface of a substrate as described below and preferably heated to form a coating film which is a liquid crystal alignment film or a coating film which becomes a liquid crystal alignment film. At this time, if the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessively large, and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases and the coating property deteriorates. There is a tendency.

  The particularly preferable range of the solid content concentration depends on the method used when the liquid crystal aligning agent is applied to the substrate. For example, in the case of using the spinner method, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is in the range of 1.5 to 4.5% by weight. Is particularly preferred. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and the solution viscosity is in the range of 3 to 15 mPa · s. The temperature for preparing the liquid crystal aligning agent is preferably 10 to 50 ° C, more preferably 20 to 30 ° C.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film according to the present invention is formed by the liquid crystal alignment agent prepared as described above. Further, the liquid crystal display element according to the present invention includes a liquid crystal alignment film formed using the above liquid crystal alignment agent. The drive mode of the liquid crystal display element is not particularly limited, and it can be applied to various drive modes such as TN type, STN type, IPS type, FFS type, VA type, MVA type and PSA type.

  The liquid crystal display element can be manufactured by, for example, a method including the following steps (1) to (3). In step (1), the substrate used differs depending on the desired drive mode. Steps (2) and (3) are common to each drive mode.

[Step (1): Formation of coating film]
First, the liquid crystal aligning agent of the present invention is applied onto a substrate, and then the applied surface is heated to form a coating film on the substrate.
(1-1) When manufacturing a TN type, STN type, VA type, MVA type or PSA type liquid crystal display element, two substrates provided with a patterned transparent conductive film are set as a pair and The liquid crystal aligning agent prepared above is applied onto the surface on which the transparent conductive film is formed, preferably by offset printing, spin coating, roll coater or inkjet printing. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, poly (alicyclic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ) and the like are used. Can be used. To obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming an unpatterned transparent conductive film, a method of using a mask having a desired pattern when forming the transparent conductive film, etc. be able to. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. You may perform the pre-processing which applies in advance.

  After the application of the liquid crystal aligning agent, preheating (prebaking) is preferably performed for the purpose of preventing liquid drip of the applied aligning agent. The prebaking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The prebaking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. After that, a baking (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, for thermal imidization of the amic acid structure present in the polymer. The baking temperature (post-baking temperature) at this time is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-2) When manufacturing an IPS-type or FFS-type liquid crystal display element, an electrode formation surface of a substrate provided with an electrode made of a comb-shaped patterned transparent conductive film or a metal film, and an electrode are provided. A liquid crystal aligning agent is applied to one surface of the counter substrate which is not formed, and then each applied surface is heated to form a coating film. The materials of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferable film thickness of the coating film formed are as described above. It is the same as (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

  In each of the cases (1-1) and (1-2) described above, after the liquid crystal aligning agent is applied onto the substrate, the organic solvent is removed to form a coating film to be an alignment film. At this time, when the polymer contained in the liquid crystal aligning agent is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imide ring structure and an amic acid structure, a coating film is formed. The coating may be further imidized by allowing the dehydration ring-closing reaction to proceed by further heating later.

[Step (2): Alignment treatment]
When manufacturing a TN-type, STN-type, IPS-type or FFS-type liquid crystal display device, a treatment (alignment treatment) for imparting a liquid crystal aligning ability to the coating film formed in the above step (1) is performed. As a result, the ability of aligning liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As the orientation treatment, for example, a rubbing treatment for imparting a liquid crystal orientation ability to the coating film by rubbing the coating film in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon and cotton, a coating film formed on a substrate A photo-alignment treatment in which the coating film is provided with a liquid crystal alignment ability by irradiating the film with light is given. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1) can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to a rubbing treatment.
In addition, with respect to the liquid crystal alignment film after the rubbing treatment, a process of changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays, Even if a liquid crystal alignment film has different liquid crystal alignment ability for each region, after forming a resist film on a part of the film, performing a rubbing process in a direction different from the previous rubbing process, and then removing the resist film. Good. In this case, it is possible to improve the visual field characteristics of the obtained liquid crystal display element.
When manufacturing a PSA type (Polymer sustained alignment) liquid crystal display element, the following step (3) may be carried out using the coating film formed in the above step (1) as it is, but the collapse of liquid crystal molecules It is also possible to carry out an alignment treatment such as a weak rubbing treatment for the purpose of controlling the above and performing alignment division by a simple method. The liquid crystal alignment film suitable for the VA type liquid crystal display element can be also suitably used for the PSA type liquid crystal display element.

[Step (3): Construction of liquid crystal cell]
(3-1) A liquid crystal cell is manufactured by preparing two substrates on which the liquid crystal alignment film is formed as described above, and disposing the liquid crystal between the two substrates arranged to face each other. For manufacturing the liquid crystal cell, for example, the following two methods can be mentioned. First, the first method is a conventionally known method. In this method, first, two substrates are arranged so as to face each other with a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together by using a sealant, and the substrate surface A liquid crystal cell is manufactured by injecting and filling liquid crystal into the cell gap defined by the sealant and then sealing the injection hole. The second method is a method called ODF (One Drop Fill) method. In this method, for example, an ultraviolet curable sealant is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed, and further a predetermined number of places on the surface of the liquid crystal alignment film are applied. After dropping the liquid crystal on the substrate, the other substrate is attached so that the liquid crystal alignment films face each other. Then, the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant to manufacture a liquid crystal cell. In either case, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used has an isotropic phase, and then gradually cooled to room temperature to remove the flow orientation at the time of filling the liquid crystal. It is desirable to do.

  As the sealing agent, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and among them, nematic liquid crystal is preferable, for example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal. A biphenylcyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubane liquid crystal, or the like can be used. In addition to these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate; chiral agents such as those sold under the product names "C-15" and "CB-15" (manufactured by Merck). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate or the like may be added and used.

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

  Then, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. As a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing plate in which a polarizing film called “H film” in which polyvinyl alcohol is stretched and oriented to absorb iodine and sandwiched between cellulose acetate protective films or the H film itself is used. A polarizing plate consisting of When the coating film is rubbed, the two substrates are arranged so that the rubbing directions of the coating films are at a predetermined angle, for example, orthogonal or antiparallel.

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

  Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, the imidization ratio of the polyimide in the polymer solution, the solution viscosity of the polymer solution, the weight average molecular weight of the polymer and the epoxy equivalent were measured by the following methods.
[Imidization rate of polyimide]
The polyimide solution was poured into pure water, the obtained precipitate was sufficiently dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidization ratio [%] was calculated by the following mathematical formula (1).
Imidization ratio [%] = (1−A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from a proton of an NH group appearing near a chemical shift of 10 ppm, A ² is a peak area derived from another proton, and α is a precursor of a polymer (polyamic acid). The ratio of the number of other protons to one proton of the NH group in).
[Solution viscosity of polymer solution]
The solution viscosity [mPa · s] of the polymer solution was measured at 25 ° C. using a E-type rotational viscometer for a solution prepared to have a polymer concentration of 10% by weight using a predetermined solvent.
[Weight average molecular weight of polymer]
The weight average molecular weight is a polystyrene conversion value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Corp., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Epoxy equivalent]
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C2105.

<Synthesis of compound>
[Synthesis Example 1A: Synthesis of compound (MDA-1)]
Compound (MDA-1) was synthesized according to the following scheme 1.

  A 0.5-liter four-necked flask equipped with a nitrogen inlet tube, a dropping funnel, a reflux condenser, a thermometer and a stirring blade was charged with 3,5-dinitroaniline (16.5 g, 0.090 mol) under a nitrogen stream. Pyridine 14.2 g (0.180 mol) and THF were added and dissolved to make the total volume 80 ml. While cooling the flask with ice water, a solution of 12.7 g (0.135 mol) of methylchloroformic acid in 90 ml of dichloromethane was added dropwise and stirred. After the dropping, the mixture was stirred at room temperature for 24 hours, 600 ml of ethyl acetate was added, and the mixture was stirred for several minutes. The whole solution was transferred to a separatory funnel, 1N hydrochloric acid solution was added and mixed, and then the aqueous layer was separated. Further, the operation of mixing with 500 ml of pure water and the operation of taking out the water layer were carried out three times, and then the lower organic layer was taken out and dried with anhydrous magnesium sulfate. The organic solvent was distilled off from the dried solution with an evaporator to obtain an intermediate (1) (yield 95%).

  Then, into a 0.5-liter four-necked flask equipped with a nitrogen introducing tube, a dropping funnel, a thermometer and a stirring blade, 4.80 g (0.020 mol) of the intermediate (1) and 25.4 g of zinc ( 0.400 mol), 4.28 g (0.080 mol) of ammonium chloride, 180 ml of THF, and 20 ml of EtOH were added and dissolved. While cooling this flask with ice water, 10 ml of pure water was dropped and stirred. After the dropping, the mixture was stirred at room temperature for 48 hours and then filtered through Celite. After adding 100 ml of ethyl acetate to the filtrate and transferring the whole amount to a separatory funnel, an operation of mixing with 300 ml of pure water and an operation of taking out an aqueous layer were carried out three times, and then a lower organic layer was taken out, This was dried over anhydrous magnesium sulfate. The organic solvent was distilled off from the dried solution with an evaporator to obtain a compound (MDA-1) (yield 87%).

[Synthesis Examples 2A and 3A: Synthesis of Compound (MDA-2) and Compound (MDA-3)]
Compound (MDA-2) and compound (MDA-3) were prepared in the same manner as the compound (MDA-1), except that ethylchloroformic acid and hexylchloroformic acid were used instead of methylchloroformic acid as starting materials. Obtained.

[Synthesis Example 4A; Synthesis of Compound (MDA-4)]
A compound (MDA-1) was prepared in the same manner as the compound (MDA-1) except that butylchloroformic acid was used as a starting material in place of butylchloroformic acid and 3,4-dinitroaniline was used in place of 2,4-dinitroaniline. -4) was obtained.

[Synthesis Example 5A; Synthesis of compound (MDA-5)]
A compound (MDA-5) was synthesized according to the following scheme 5.

  In a four-necked flask having a capacity of 0.5 liter equipped with a nitrogen introducing tube, a dropping funnel, a reflux condenser, a thermometer and a stirring blade, 1.53 g (0.025 mol) of aminoethanol and 7 potassium fluoride under a nitrogen stream. 0.25 g (0.125 mol), potassium carbonate 17.3 g (0.125 mol) and THF were added and dissolved to make the total volume 80 ml. While cooling this flask with ice water, 3.20 g (0.026 mol) of propylchloroformic acid was added dropwise and stirred. After the dropping, the mixture was stirred at room temperature for 24 hours and then filtered through Celite. After adding 300 ml of ethyl acetate to the filtrate, the whole solution was transferred to a separatory funnel, and 500 ml of pure water was added and mixed, and then the aqueous layer was separated. After performing this three times in total, the lower organic layer was taken out and dried over anhydrous magnesium sulfate. The organic solvent was distilled off from the dried solution with an evaporator to obtain an intermediate (2) (yield 85%). Then, using the intermediate (2) and 3,5-dinitrobenzoic acid chloride, a compound (MDA-5) was obtained by a method similar to the method of synthesizing the compound (MDA-1).

[Synthesis Example 6A: Synthesis of compound (MDA-6)]
Compound (MDA-6) was obtained by the same method as the synthesis method of compound (MDA-5) except that aminobutanol was used instead of aminoethanol as a starting material.

[Synthesis Example 7A: Synthesis of compound (MDA-7)]
A compound (MDA-7) was synthesized according to the following scheme 7.

  In a 4-necked flask having a capacity of 0.5 liter equipped with a nitrogen introduction tube, a dropping funnel, a reflux condenser, a thermometer and a stirring blade, 6.00 g (0.100 mol) of diaminoethane and 3.16 g of pyridine under a nitrogen stream. (0.040 mol) and THF were added and dissolved to make the total volume 80 ml. While cooling this flask with ice water, 2.16 g (0.020 mol) of ethylchloroformic acid was added dropwise and stirred. After the dropping, the mixture was stirred at room temperature for 24 hours and then filtered through Celite. After adding 300 ml of ethyl acetate to the filtrate, the whole solution was transferred to a separatory funnel, and 500 ml of pure water was added and mixed, and then the aqueous layer was separated. After performing this a total of 3 times, the lower organic layer was taken out and dried over anhydrous magnesium sulfate. The organic solvent was distilled off from the dried solution with an evaporator to obtain an intermediate (3) (yield 81%). Then, using the intermediate (3) and 3,5-dinitrobenzoic acid chloride, a compound (MDA-7) was obtained by a method similar to the method for synthesizing the compound (MDA-1).

[Synthesis Example 8A: Synthesis of compound (MDA-11)]
A compound (MDA-11) was synthesized according to the following scheme 8.

To a four-necked flask with a capacity of 0.5 liter equipped with a nitrogen introducing tube and a stirring blade, 10.7 g (0.050 mol) of 2-phenoxybenzoic acid and 100 ml of mixed acid were added under a nitrogen stream, and placed in an oil bath at 60 ° C. And stirred for 6 hours. Then, sodium hydroxide was added for neutralization. The entire solution was transferred to a separatory funnel, 300 ml of ethyl acetate and 500 ml of a saturated aqueous solution of ammonium chloride were added and mixed, and then the aqueous layer was separated. The liquid separation operation was performed three times in total, and then the organic layer was taken out and dried over anhydrous magnesium sulfate. The organic solvent was distilled off from the dried solution with an evaporator to obtain 2- (4-nitro) phenoxy-5-nitrobenzoic acid (yield 80%).
Next, in a four-necked flask having a capacity of 0.5 liter equipped with a nitrogen introduction tube, a dropping funnel, a reflux condenser, a thermometer and a stirring blade, 2- (4-nitro) phenoxy-5-nitro was introduced under a nitrogen stream. Benzoic acid (6.08 g, 0.020 mol), diphenylphosphoric acid azide (DPPA) (6.61 g, 0.024 mol), triethylamine (2.87 g, 0.028 mol) and dehydrated toluene (100 ml) were added and the mixture was stirred at room temperature for 3 hours. Then, the mixture was heated under reflux at 120 ° C. for 2 hours. Thereafter, the whole solution was transferred to a separatory funnel, 300 ml of ethyl acetate and 500 ml of a saturated aqueous solution of ammonium chloride were added and mixed, and then the aqueous layer was separated. The liquid separation operation was performed three times in total, and then the organic layer was taken out and dried over anhydrous magnesium sulfate. The organic solvent was distilled off from the dried solution with an evaporator to obtain 2- (4-nitro) phenoxy-5-nitro-cyanatobenzene (yield 85%).
Next, in a 4-necked flask having a capacity of 0.5 liter equipped with a nitrogen introduction tube, a stirring blade and a dropping funnel, 6.02 g of 2- (4-nitro) phenoxy-5-nitro-cyanatobenzene was introduced under a nitrogen stream. (0.020 mol) and 50 ml of dehydrated methylene chloride were added and stirred. Then, 10 ml of dehydrated methanol was dropped using a dropping funnel. The resulting solution was distilled off with an evaporator to obtain 2- (4-nitro) phenoxy-5-nitro-N-methoxycarbonylaniline (yield 95%).
Next, a compound (MDA-11) was obtained by the same method as the synthesis method for obtaining the compound (MDA-1) from the intermediate (1) in Synthesis Example 1A (yield 89%).

[Synthesis Example 9A: Synthesis of compound (MDA-14)]
A compound (MDA-14) was synthesized according to the following scheme 9.

2.94 g (0.020 mol) of the intermediate (2) obtained in Synthesis Example 5A and a 2- (2) obtained in Synthesis Example 8A were placed in a 0.5-liter four-necked flask equipped with a nitrogen introducing tube and a stirring blade. 4-nitro) phenoxy-5-nitrobenzoic acid 6.08 g (0.020 mol), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) 5.75 g (0.030 mol), 4- Dimethylaminopyridine (DMAP) 0.49 g (0.004 mol) was added under a nitrogen stream, and the mixture was stirred at room temperature for 12 hours. Then, the whole solution was transferred to a separatory funnel, 300 ml of ethyl acetate and 500 ml of a saturated aqueous solution of ammonium chloride were added and mixed, and then the aqueous layer was separated. The liquid separation operation was performed three times in total, and then the organic layer was taken out and dried over anhydrous magnesium sulfate. The organic solvent was distilled off from the dried solution with an evaporator to obtain an intermediate (4) (yield 88%).
Next, the compound (MDA-14) was obtained by the same method as the method for synthesizing the compound (MDA-1) from the intermediate (1) in Synthesis Example 1A (yield 80%).

<Synthesis of polymer>
[Synthesis Example 1: Synthesis of Polyimide (PI-1)]
100 mol parts of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic acid dianhydride, 60 mol parts of p-phenylenediamine (PDA) as diamine, cholestanyl 3,5-diaminobenzoate (HCDA) ) 20 mol parts and a compound (MDA-1) 20 mol parts are melt | dissolved in N-methyl-2-pyrrolidone (NMP), it is made to react at 60 degreeC for 6 hours, and the solution containing 20 weight% of polyamic acid. Obtained. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 56 mPa · s.
Next, NMP was added to the obtained polyamic acid solution to form a solution having a polyamic acid concentration of 7% by weight, and pyridine and acetic anhydride were added to each of the tetracarboxylic acid dianhydride in an amount of 1.0 times the total amount. Each of them was added by mole and dehydration ring closure reaction was carried out at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP (the pyridine and acetic anhydride used in the dehydration ring-closing reaction were removed outside the system by this operation. The same applies to the following). A solution containing 26% by weight of polyimide (PI-1) was obtained.

[Synthesis Examples 2 to 15 and 22]
Polyimide (PI-2) was prepared in the same manner as in Synthesis Example 1 except that the types and amounts of tetracarboxylic dianhydride and diamine used, and the amounts of pyridine and acetic anhydride used for imidization were changed as shown in Table 1 below. )-(PI-16) were each synthesize | combined. The measurement results of the imidization ratio of the obtained polymer are also shown in Table 1 below. In Synthesis Example 8, 1.5 parts by mole of aniline was blended as a monoamine together with tetracarboxylic dianhydride and diamine.

In Table 1, the values in parentheses for tetracarboxylic dianhydride represent the ratio [mol part] to the total 100 mol parts of the tetracarboxylic dianhydride used in the synthesis of the polymer. The numerical values in parentheses for diamine and monoamine represent the ratio [mol part] of the tetracarboxylic dianhydride used for the synthesis of the polymer to 100 mol parts in total. The abbreviations in Table 1 have the following meanings. In addition, "-" in Table 1 means that the compound in the corresponding column was not used.
<Tetracarboxylic acid dianhydride>
t-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA)
t-2: 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride (BODA)
t-3: 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CB)
t-4: 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1, 3-dione (MTDA)
t-5: pyromellitic dianhydride (PMDA)
t-6: 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride (PMDA-HS)
<Diamine>
d-1: compound represented by the following formula (d-1) d-2: compound represented by the following formula (d-2) d-3: p-phenylenediamine (PDA)
d-4: 4,4'-diaminodiphenylmethane d-5: 4,4'-diaminodiphenyl ether d-6: 2,2'-dimethyl-4,4'-diaminobiphenyl d-7: 2,2'-bis (Trifluoromethyl) -4,4'-diaminobiphenyl d-8: 3,5-diaminobenzoic acid (35DAB)
d-9: 1,3-bis (3-aminopropyl) -tetramethyldisiloxane d-10: 3,5-diaminocholestanyl benzoate (HCDA)
d-11: Cholestanyloxy-2,4-diaminobenzene (HCODA)
d-12: 3,6-bis (4-aminobenzoyloxy) cholestane d-13: compound represented by the above formula (D-1-5) d-14: 1,3-diamino-4- {4- [Trans-4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene (a compound represented by the above formula (D-1-2))
d-15: 1,4-benzenedicarboxylic acid bis (4-aminophenyl)
mda-11: Compound represented by the following formula (mda-11) mda-12: Compound represented by the following formula (mda-12) mda-13: Compound represented by the following formula (mda-13) mda- 14: a compound represented by the following formula (mda-14)
<Monoamine>
m-1: aniline

[Synthesis Example 16: Synthesis of polyamic acid (PA-1)]
1,2,3,4-Cyclobutanetetracarboxylic dianhydride (CB) 100 parts by mole as the tetracarboxylic dianhydride, 30 parts by mole of the compound represented by the formula (d-1) as the diamine, 2,2 Mixing 40 mol parts of'-dimethyl-4,4'-diaminobiphenyl and 30 mol parts of the compound (MDA-1) with NMP and γ-butyrolactone (γBL) (NMP: γBL = 10: 90 (weight ratio)). It was dissolved in a solvent and reacted at 40 ° C. for 3 hours to obtain a solution containing 10% by weight of polyamic acid (PA-1). The solution viscosity of the obtained polyamic acid solution measured in a small amount was 180 mPa · s.

[Synthesis Example 17: Synthesis of polyamic acid (PA-2)]
A solution containing 10% by weight of polyamic acid (PA-2) by performing the same operation as in Synthesis Example 16 except that the types and amounts of the tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 above. Got The solution viscosity of the obtained polyamic acid solution measured in a small amount was 210 mPa · s.
[Synthesis Example 18: Synthesis of polyamic acid (PA-3)]
A solution containing 10% by weight of polyamic acid (PA-3) by performing the same operation as in Synthesis Example 16 except that the types and amounts of the tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 above. Got The solution viscosity of the obtained polyamic acid solution measured in a small amount was 230 mPa · s.

[Synthesis Example 19: Synthesis of polyorganosiloxane (APS-1)]
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (ECETS), 500 g of methyl isobutyl ketone and 10.0 g of triethylamine were placed. Charged and mixed at room temperature. Next, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then the reaction was carried out at 80 ° C. for 6 hours while stirring under reflux. After completion of the reaction, the organic layer was taken out, washed with a 0.2% by weight aqueous ammonium nitrate solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a reactive polyorganosiloxane. (EPS-1) was obtained as a viscous transparent liquid. As a result of ¹ H-NMR analysis of this reactive polyorganosiloxane, a peak based on an epoxy group was obtained in the vicinity of a chemical shift (δ) = 3.2 ppm according to the theoretical intensity, and a side reaction of the epoxy group was observed during the reaction. It was confirmed that was not happening. The weight average molecular weight Mw of the obtained reactive polyorganosiloxane was 3,500, and the epoxy equivalent was 180 g / mol.
Then, in a 200 mL three-necked flask, 10.0 g of reactive polyorganosiloxane (EPS-1), 30.28 g of methyl isobutyl ketone as a solvent, 3.98 g of 4-dodecyloxybenzoic acid as a reactive compound, and UCAT as a catalyst. 18X (trade name, manufactured by San-Apro Co., Ltd.) (0.10 g) was charged, and the reaction was carried out at 100 ° C. for 48 hours with stirring. After the reaction was completed, ethyl acetate was added to the reaction mixture to wash the resulting solution three times with water, the organic layer was dried using magnesium sulfate, and the solvent was distilled off to give a liquid crystal aligning polyorganosiloxane (APS- 9.0 g of 1) was obtained. The weight average molecular weight Mw of the obtained polymer was 9,900.

[Synthesis Example 20: Synthesis of polyamic acid (PA-4)]
A solution containing 10% by weight of polyamic acid (PA-4) by performing the same operation as in Synthesis Example 16 except that the types and amounts of the tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 above. Got The solution viscosity of the obtained polyamic acid solution measured in a small amount was 212 mPa · s.
[Synthesis Example 21: Synthesis of polyamic acid (PA-5)]
A solution containing 10% by weight of polyamic acid (PA-5) by performing the same operation as in Synthesis Example 16 except that the types and amounts of the tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 above. Got The solution viscosity of the obtained polyamic acid solution measured in a small amount was 250 mPa · s.

[Example 1]
<Preparation of liquid crystal aligning agent>
To the polyimide (PI-1) obtained as a polymer, NMP and butyl cellosolve (BC) were added as organic solvents, the solvent composition was NMP: BC = 50: 50 (weight ratio), and the solid content concentration was 6.0% by weight. And A liquid crystal aligning agent (S1) was prepared by filtering this solution using a filter having a pore size of 1 μm.

<Manufacture of VA type liquid crystal cell>
The liquid crystal aligning agent prepared above was applied onto a transparent electrode surface of a glass substrate with a transparent electrode (thickness 1 mm) made of an ITO film using a liquid crystal aligning film printer (manufactured by Nissha Printing Co., Ltd.), It was heated on a hot plate at 80 ° C. for 1 minute (pre-baking), and further heated on a hot plate at 200 ° C. for 60 minutes (post-baking) to form a coating film (liquid crystal alignment film) with an average film thickness of 0.08 μm. . This operation was repeated to obtain a pair (two) of glass substrates each having a liquid crystal alignment film on the transparent conductive film. Next, on one of the pair of substrates, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edge of the surface having the liquid crystal alignment film, and then the pair of substrates was attached to the liquid crystal alignment film surface. Were overlapped and pressure-bonded so as to face each other, and the adhesive was cured. Then, after filling a nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) between the pair of substrates from the liquid crystal inlet, the liquid crystal inlet was sealed with an acrylic photo-curing adhesive to manufacture a VA type liquid crystal cell. .

<Reliability evaluation>
The reliability of the liquid crystal display element was evaluated using the liquid crystal cell manufactured as described above. The evaluation was performed as follows. First, a voltage of 5 V was applied to the above liquid crystal cell for 60 microseconds for a duration of 167 milliseconds, and the voltage holding ratio (VHR1) was measured 167 milliseconds after the application was released. Then, the liquid crystal cell was allowed to stand in an oven at 80 ° C. under irradiation with an LED lamp for 200 hours, then allowed to stand at room temperature and naturally cooled to room temperature. After cooling, a voltage of 5 V was applied to the liquid crystal cell for an application time of 60 microseconds and a span of 167 milliseconds, and the voltage holding ratio (VHR2) was measured 167 milliseconds after the application was released. The measuring device used was "VHR-1" manufactured by Toyo Corp. The rate of change of VHR (ΔVHR) at this time was calculated by the following mathematical expression (2), and the reliability was evaluated by ΔVHR. The evaluation is that if ΔVHR is less than 1%, the reliability is “excellent (⊚)”, and if 1% or more and less than 2%, the reliability is “good”, 2% or more and less than 3%. The reliability was "good (△)" when it was 3%, and the reliability was "poor (x)" when it was 3% or more. As a result, in Example 1, ΔVHR = 1.9 [%], and the reliability was “good (◯)”.
ΔVHR [%] = (VHR1−VHR2) / (VHR1) × 100 (2)

<Evaluation of outgas amount>
The liquid crystal aligning agent (S1) was applied onto the substrate by the same operation as in the production of the liquid crystal cell, and prebaking and postbaking were performed to form a coating film on the substrate. The amount of outgas of the substrate after the post-baking was analyzed using pyrolysis gas chromatography (JPS-700 manufactured by Nippon Analytical Industry Co., Ltd., pyrolysis condition 590 ° C. × 5 sec, GC column BPX-5). For the outgas amount, a calibration curve was prepared using a standard product, and the detected substance amount (%) was calculated by comparing the amount of the introduced pyrolyzable monomer with the substance amount. The evaluation is “excellent (⊚)” when the amount of detected substance is less than 4%, “good (◯)” when 4% or more and less than 7%, and 7% or more and less than 10%. The case was rated as "OK", and the case of 10% or more was rated as "Poor". As a result, in Example 1, the amount of outgas was small and the evaluation was “excellent (⊚)”.

[Examples 2 to 6, Examples 10 to 11 and Comparative Examples 1 to 5]
Liquid crystal aligning agents were prepared in the same manner as in Example 1 except that the composition of the liquid crystal aligning agents was changed as shown in Table 2 below. Further, a liquid crystal cell was manufactured in the same manner as in Example 1 using each liquid crystal aligning agent, and the manufactured liquid crystal cell was evaluated. The evaluation results are shown in Table 2 below.

[Example 7]
Γ-Butyrolactone (BL), NMP and butyl cellosolve (BC) were used as organic solvents so that the polyimide (PI-8) obtained as a polymer and the polyamic acid (PA-1) had a solid content weight ratio of 20:80. In addition, a solution having a solvent composition of BL: NMP: BC = 70: 15: 15 (weight ratio) and a solid content concentration of 6.0% by weight was prepared. A liquid crystal aligning agent (S7) was prepared by filtering this solution with a filter having a pore size of 1 μm.

<Manufacture of TN type liquid crystal cell>
The liquid crystal aligning agent prepared above was applied to a transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a liquid crystal aligning film printer (manufactured by Nissha Printing Co., Ltd.), and then on a hot plate at 80 ° C. After heating (pre-baking) for 1 minute to remove the solvent, heating (post-baking) was performed for 10 minutes on a hot plate at 200 ° C. to form a coating film having an average film thickness of 0.08 μm. This coating film was rubbed by a rubbing machine having a roll around which a rayon cloth was wound at a roll rotation speed of 400 rpm, a stage moving speed of 30 mm / sec, and a foot pressing length of 0.4 mm to give a liquid crystal aligning ability. . After that, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then drying was performed in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. Further, the above operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, one of the pair of substrates was coated with an epoxy resin adhesive containing 5.5 μm diameter aluminum oxide spheres on the outer edge of the surface having the liquid crystal alignment film, and then paired so that the rubbing directions were orthogonal to each other. The substrates were laminated and pressure-bonded so that the liquid crystal alignment film surfaces faced each other, and the adhesive was cured. Then, after filling a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) between the pair of substrates from the liquid crystal inlet, the liquid crystal inlet is sealed with an acrylic photo-curable adhesive to form a TN liquid crystal cell. Manufactured.
<Evaluation of reliability and amount of outgas>
When the reliability and the outgas amount were evaluated by the same method as in Example 1 using the TN type liquid crystal cell manufactured above, ΔVHR = 0.6 [%], the reliability was “excellent”, and the outgas amount was It was 6% and was evaluated as “good”.

[Example 8]
<Preparation of liquid crystal aligning agent>
Γ-Butyrolactone (BL), NMP and butyl cellosolve (BC) were used as organic solvents so that the polyimide (PI-9) obtained as a polymer and the polyamic acid (PA-2) had a solid content weight ratio of 40:60. In addition, the solvent composition was BL: NMP: BC = 40: 40: 20 (weight ratio), and the solution had a solid content concentration of 6.0% by weight. A liquid crystal aligning agent (S8) was prepared by filtering this solution with a filter having a pore size of 1 μm.

<Manufacture of IPS / FFS type liquid crystal cell>
The liquid crystal aligning agent prepared above was applied to a transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a liquid crystal aligning film printer (manufactured by Nissha Printing Co., Ltd.), and then on a hot plate at 80 ° C. After heating (pre-baking) for 1 minute to remove the solvent, heating (post-baking) was performed for 10 minutes on a hot plate at 200 ° C. to form a coating film having an average film thickness of 0.08 μm. The coating film was subjected to a rubbing treatment with a rubbing machine having a roll around which a rayon cloth was wound at a roll rotation speed of 1000 rpm, a stage moving speed of 20 mm / sec, and a push-in length of 0.4 mm to give a liquid crystal aligning ability. . After that, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then drying was performed in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. Further, the above operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, after applying an epoxy resin adhesive containing 5.5 μm diameter aluminum oxide spheres to the outer edge of the surface having the liquid crystal alignment film on one of the pair of substrates, the rubbing directions are antiparallel. Then, a pair of substrates were superposed on each other so that the liquid crystal alignment film surfaces faced each other and pressure-bonded to cure the adhesive. Then, after filling a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to obtain an IPS / FFS type liquid crystal. A cell was manufactured.
<Evaluation of reliability and amount of outgas>
Using the IPS / FFS type liquid crystal cell manufactured as described above, the reliability and the amount of outgas were evaluated by the same method as in Example 1 above. As a result, ΔVHR = 0.6 [%] and the reliability was “excellent”, The amount was 6%, which was evaluated as “good”.

[Example 9]
<Preparation of liquid crystal aligning agent>
NMP and butyl cellosolve (BC) were added as organic solvents so that the polyimide (PI-10) obtained as a polymer and the polyorganosiloxane (APS-1) had a solid content weight ratio of 95: 5, and the solvent composition was NMP. : BC = 50: 50 (weight ratio) and a solid content concentration of 6.0% by weight. A liquid crystal aligning agent (S9) was prepared by filtering this solution with a filter having a pore size of 1 μm.

<Preparation of liquid crystal composition>
[Preparation of Liquid Crystal Composition LC1]
A liquid crystal composition LC1 was obtained by adding 0.3% by weight of a photopolymerizable compound represented by the following formula (pc-1) to 10 g of nematic liquid crystal (MLC-6608 manufactured by Merck Ltd.) and mixing them. .

<Production of PSA-VA type liquid crystal cell>
The liquid crystal aligning agent prepared above was patterned into a slit shape as shown in FIGS. 1 to 3, and a liquid crystal aligning film was formed on each electrode surface of two glass substrates each having an ITO electrode partitioned into a plurality of regions. After coating using a printing machine (manufactured by Nissha Printing Co., Ltd.) and heating (pre-baking) on a hot plate at 80 ° C for 1 minute to remove the solvent, heating on a hot plate at 200 ° C for 10 minutes (post) After baking, a coating film having an average film of 800 Å was formed. Further, the above operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film. The electrode pattern used is the same type as the electrode pattern in the PSA mode.
Next, on one of the pair of substrates, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edge of the surface having the liquid crystal alignment film, and then the pair of substrates was attached to the liquid crystal alignment film surface. Were overlapped with each other so as to face each other and pressure-bonded to cure the adhesive. Next, the liquid crystal composition LC1 prepared above was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive. After that, light irradiation was performed with an irradiation amount of 100,000 J / m ² in a state where a voltage was applied between the conductive films of the obtained liquid crystal cell. As a result, a PSA-VA type liquid crystal cell was obtained.
<Evaluation of reliability and amount of outgas>
Using the PSA-VA type liquid crystal cell manufactured as described above, the reliability and the amount of outgas were evaluated by the same method as in Example 1 above. ΔVHR = 0.4 [%] and the reliability was “excellent”, and the outgas amount was high. The amount was 2%, which was evaluated as "excellent".

[Example 12]
<Preparation of liquid crystal aligning agent>
To the polyamic acid (PA-3) obtained as a polymer, NMP and butyl cellosolve (BC) were added as an organic solvent, the solvent composition was NMP: BC = 50: 50 (weight ratio), and the solid content concentration was 6.0% by weight. It was a solution. A liquid crystal aligning agent (S12) was prepared by filtering this solution with a filter having a pore size of 1 μm.

<Manufacture of IPS / FFS type liquid crystal cell using photo-alignment method>
The liquid crystal aligning agent prepared above was applied to a transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a liquid crystal aligning film printer (manufactured by Nissha Printing Co., Ltd.), and then on a hot plate at 80 ° C. The solvent was removed by heating (prebaking) for 1 minute. Thereafter, using a Hg-Xe lamp, polarized ultraviolet rays including a bright line of 254 nm were irradiated from the substrate normal line at an irradiation dose of 700 mJ / cm ² , and then heated (post-baked) on a hot plate at 200 ° C. for 10 minutes. Thus, a coating film having an average film thickness of 800Å provided with a liquid crystal alignment film was formed. Further, the above operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, on one of the pair of substrates, an epoxy resin adhesive containing 5.5 μm diameter aluminum oxide spheres was applied to the outer edge of the surface having the liquid crystal alignment film, and then the polarization plane of polarized ultraviolet light was applied to the substrate. The pair of substrates were stacked and pressure-bonded so that the surfaces of the liquid crystal alignment films face each other so that the projected directions were parallel, and the adhesive was cured. Then, after filling a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to obtain an IPS / FFS type liquid crystal. A cell was manufactured.

<Evaluation of reliability and amount of outgas>
Using the IPS / FFS type liquid crystal cell manufactured by the photo-alignment method as described above, the reliability and the outgas amount were evaluated by the same method as in Example 1 above. As a result, ΔVHR = 0.5 [%], and the reliability was "Excellent" and the amount of outgas was 3%, which was evaluated as "excellent".

[Examples 13 to 14]
Liquid crystal aligning agents were prepared in the same manner as in Example 12 except that the composition of the liquid crystal aligning agents was changed as shown in Table 2 below. A liquid crystal cell was manufactured in the same manner as in Example 12 using each liquid crystal aligning agent, and the manufactured liquid crystal cell was evaluated. The evaluation results are shown in Table 2 below.

  In Table 2, the numerical value of the amount of the polymer represents the use ratio [parts by weight] of each polymer to 100 parts by weight in total of the polymers used for preparing the liquid crystal aligning agent.

As shown in Table 2, in Examples 1 to 14, the reliability was evaluated as "excellent" to "good", and the amount of outgas was small. On the other hand, in Comparative Examples 1 to 5, reliability was evaluated as “poor”, and in Comparative Example 4, the amount of outgas was large and evaluated as “poor”.
In Comparative Examples 2, 3 and 5 using the thermally decomposable monomer having a tertiary alkyl structure, the reason why the reliability evaluation was lower than that of the example is not clear, but in the case of the tertiary alkyl structure, It is considered that one of the factors is that the cross-linking reaction is less likely to proceed as compared with those in the examples, since it is mainly decarboxylated to generate an amino group. Further, in Comparative Example 4 in which a diamine having a straight chain structure having 10 carbon atoms is used as the thermally decomposable monomer, it is speculated that outgas was likely to be generated due to the carbon chain being too long.

  1 ... ITO electrode, 2 ... slit part, 3 ... light-shielding film

Claims (7)

Polyamic acid, polyamic acid ester, containing at least one polymer selected from the group consisting of polyimide and polyamide,
A group consisting of a partial structure derived from a specific diamine, which is a diamine having a structure represented by the following formula (1), and a nitrogen-containing heterocycle, a secondary amino group and a tertiary amino group A partial structure derived from a diamine having at least one nitrogen-containing structure selected from a polymer (P),
The polymer (P) is 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-. Dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride and 1,2,4,5-cyclohexanetetracarboxylic dianhydride have a partial structure derived from the acid anhydride is at least one selected from the group consisting of anhydride,
The diamine having a nitrogen-containing structure is 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1, 4-bis- (4-aminophenyl) -piperazine, and at least one selected from the group consisting of compounds represented by the following formulas (D-2-1) to (D-2-6),
The proportion of the partial structure derived from the specific diamine is 1 mol% or more and 90 mol% or less, and the diamine having the nitrogen-containing structure, with respect to the total amount of the partial structure derived from the diamine contained in the polymer (P). A liquid crystal aligning agent in which the ratio of the partial structure derived from is 0.1 mol% or more and 60 mol% or less .
(In formula (1), A ¹ and A ² are each independently a hydrogen atom or a monovalent organic group, and the total number of carbon atoms of A ¹ and A ² is 0 to 7. Y ¹ is an oxygen atom. Or a sulfur atom, R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, X ¹ is a single bond or a divalent organic group, and “*” represents a bond. )
The liquid crystal aligning agent according to claim 1, wherein the polymer (P) is a polymer having a partial structure derived from a diamine represented by the following formula (c) as a partial structure derived from the specific diamine .
(In the formula (c), B ¹ is a divalent organic group having a partial structure represented by the above formula (1), and B ² and B ³ are each independently a hydrogen atom or the above formula (1). Is a monovalent organic group having a partial structure represented by, Z ¹ and Z ² are each independently a single bond or a divalent linking group, and R ⁵ and R ⁶ are each independently a halogen atom or It is a monovalent hydrocarbon group having 1 to 6 carbon atoms, n1 and n2 are each independently an integer of 0 to 2, and m1 and m2 are each independently 0 or 1, provided that m1 = 1. In the case of, B ² has a partial structure represented by the above formula (1), and when m1 = 0 and m2 = 0, at least one of B ² and B ³ is represented by the above formula (1). has a partial structure that, in the case of m1 = 0 and m @ 2 = ^1, Sukunakutomoizu of B 1, ^{B 2} and ^{B 3} Or has the partial structure represented by the above formula (1).) The liquid crystal aligning agent according to claim 1 or 2, wherein the polymer (P) is a polymer having a partial structure derived from a diamine represented by the following formula (d) as a partial structure derived from the specific diamine. .
(In the above formula (d), R ⁷ is a halogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, and n 3 is an integer of 0 to ^2. A ¹ , A ² , Y ¹ , and R. ¹ and X ¹ are respectively synonymous with the above formula (1).)   In the diaminophenyl group contained in the compound represented by the above formula (d), two primary amino groups are bonded to the 3,5-position with respect to the structure represented by the above formula (1). The liquid crystal aligning agent according to claim 3. The polymer (P) is a polymer having a partial structure derived from a diamine represented by the following formula (e) as a partial structure derived from the specific diamine, according to any one of claims 1 to 4. The liquid crystal aligning agent described.
(In formula (e), Z ³ is a single bond or a divalent linking group, V ¹ is a hydrogen atom or a monovalent group represented by the above formula (1), and R ⁸ and R ⁹ are , Each independently a halogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, n4 and n5 each independently represent an integer of 0 to ^2. A ¹ , A ² , Y ¹ , R ¹ and X ¹ has the same meaning as in the above formula (1).) Liquid crystal alignment film formed by using the liquid crystal aligning agent according to any one of claims 1-5. A liquid crystal display device comprising the liquid crystal alignment film according to claim 6 .