JP2007332357A - Vertically orientated liquid crystal aligning agent and vertically orientated liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertically orientated liquid crystal orientating agent which has a high voltage retention and exhibits good applicability to a substrate. <P>SOLUTION: The agent comprises a polymer which has an amic acid repeating unit and/or an imide repeating unit, wherein the group derived from the diamine in the repeating unit comprises, for example, a group derived from both at least one of a specific diamine such as dodecanoxy-2,4-diaminobenzene or having a steroid skeletal, and another specific diamine such as 1,4-bis(aminomethyl)-bicyclo[2,2,1]heptane. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display element having a vertical alignment liquid crystal aligning agent and a vertical alignment liquid crystal alignment film. More specifically, the present invention relates to a liquid crystal display element having a vertical alignment type liquid crystal aligning agent and a vertical alignment type liquid crystal alignment film that exhibits good printability and is excellent in various electrical characteristics.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A nematic liquid crystal layer having positive dielectric anisotropy is formed in a cell having a sandwich structure so that the major axis of the liquid crystal molecules is continuously twisted 90 degrees from one substrate to the other. A TN type liquid crystal display element having a so-called TN type (Twisted Nematic) liquid crystal cell is known.
Further, STN (Super Twisted Nematic) type liquid crystal display elements and vertical alignment type liquid crystal display elements, which have a higher contrast than the TN type liquid crystal display elements and have less viewing angle dependency, have been developed. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of liquid crystal molecules is continuously twisted over 180 degrees between substrates. The birefringence effect generated by the above is utilized.

  In recent years, the development of new liquid crystal display elements has also been active, and as one of them, two electrodes for driving a liquid crystal are arranged in a comb shape on one substrate, and an electric field parallel to the substrate surface is arranged. A lateral electric field type liquid crystal display element that generates liquid crystal and controls liquid crystal molecules has been proposed. This element is generally called an in-plane switching type (IPS type), and is known for its excellent wide viewing angle characteristics. Recently, an optical compensation film is used to further improve the wide viewing angle characteristics, so that it is possible to obtain a wide viewing angle comparable to that of a cathode ray tube without tone reversal or color change.

As a liquid crystal display element different from the above, a vertical alignment type called an MVA (Multi domain Vertical Alignment) method or a PVA (Patterned Vertical Alignment) method in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicularly to a substrate. Liquid crystal display elements have been proposed. These MVA type and PVA type liquid crystal display elements are excellent not only in viewing angle and contrast, but also in terms of manufacturing processes, such as not having to perform a rubbing treatment in forming a liquid crystal alignment film.
Conventionally, these liquid crystal alignment films have excellent heat resistance, affinity with liquid crystals, or mechanical strength, so in any display mode, polyamic acid or polyimide obtained by dehydrating and ring-closing this has been used in many liquid crystal display elements. Yes.

Currently, a liquid crystal alignment film of a vertical alignment type liquid crystal display element is formed by applying a liquid crystal alignment agent to a substrate as described in Patent Document 1, and as a basic characteristic, a vertical alignment capable of vertically aligning liquid crystals. Sexuality is required. In recent years, with the spread of the vertical alignment type liquid crystal display element, the demand for improvement in display quality and productivity that can be achieved by the vertical type liquid crystal alignment film is becoming higher. There are various characteristics required for the alignment film, but as the most important characteristics among them, as described in Patent Documents 1 to 4, for high voltage holding characteristics and good coating properties on the substrate. An improvement is mentioned. In general, in order to achieve a high voltage holding characteristic, as described in Patent Document 5, a technique is known in which the polyimide used in the alignment film has a high imidization ratio. However, since the increase in the imidization ratio decreases the solubility in a solvent, the range of solvents that can be used is limited, and as a result, it becomes difficult to achieve good coating properties. Thus, the improvement of the imidization ratio that can provide high voltage holding characteristics greatly deteriorates the coating property, and thus becomes a trade-off relationship, which is a problem.
Japanese Patent Laid-Open No. 2002-327058 JP 2002-162630 A JP 2004-67589 A JP 2005-308924 A JP 2004-163724 A

  An object of the present invention is to provide a vertical alignment type liquid crystal aligning agent having high voltage holding characteristics and good coating properties on a substrate.

  Another object of the present invention is to provide a vertical alignment type liquid crystal display element having a liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention and exhibiting high voltage holding characteristics.

  Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are as follows. First, an amic acid repeating unit represented by the following formula (I-1) and an imide repeating unit represented by the following formula (I-2): It consists of a polymer comprising at least one repeating unit, and Q ^{1 in the} above formula (I-1) and Q ² in the above formula (I-2) are represented by the following formulas (II-1) and (II-2) A vertical alignment comprising at least one of divalent organic groups represented by each and at least one of divalent organic groups represented by the following formula (III-1): This is achieved by the type liquid crystal aligning agent.

(Here, P ¹ represents a tetravalent organic group constituting tetracarboxylic acid, and Q ¹ represents a divalent organic group constituting diamine.)

(Here, P ² represents a tetravalent organic group constituting tetracarboxylic acid, and Q ² represents a divalent organic group constituting diamine.)

（上式中、Ｘ^１は、単結合、−Ｏ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−、−Ｓ−、メチレン基、炭素数２〜６のアルキレン基またはフェニレン基であり、Ｒ^１は、炭素数１０〜２０のアルキル基、炭素数４〜４０の脂環式骨格を有する一価の有機基または炭素数６〜２０のフッ素原子を有する一価の有機基であり、Ｒ^２は、炭素数４〜４０の脂環式骨格を有する二価の有機基または炭素数５〜３０のフッ素原子を有する二価の有機基である。）

(In the above formula, X ¹ represents a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, a methylene group, or an alkylene having 2 to 6 carbon atoms. R ¹ is a group having 10 to 20 carbon atoms, a monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent having a fluorine atom having 6 to 20 carbon atoms. R ² is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms or a divalent organic group having a fluorine atom having 5 to 30 carbon atoms.)

(In the above formula, X ² is a methylene group or an alkylene group having 2 to 20 carbon atoms, and R ³ is an aromatic ring-containing skeleton, an organosiloxane skeleton, —R— (O—C ₂ H ₄ ) _n —O. divalent organic group represented by -R- (R represents an alkylene radical, n is 1 to 100 of 2 to 5 carbon _{atoms), - R- (O-C} 3 H 6) n -O-R- A divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms (R is an alkylene group having 2 to 5 carbon atoms, n is 1 to 50), and And a plurality of X ² present in the formula may be the same or different.)

According to the present invention, the above objects and advantages of the present invention are as follows. Secondly, P ¹ in the above formula (I-1) and P ² in (I-2) are represented by the following formula (IV-1) to It is achieved by a vertical alignment type liquid crystal aligning agent containing at least one of tetravalent organic groups represented by each of (IV-6).

(Here, R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom or a monovalent organic group.)

According to the present invention, the above objects and advantages of the present invention are as follows. Thirdly, P ¹ in the above formula (I-1) and P ² in (I-2) are represented by the above formula (IV-5) and Vertical alignment characterized by containing at least one of the tetravalent organic groups represented by each of (IV-6) in an amount of 50 mol% or more based on the total tetravalent organic groups (P ¹ + P ² ). This is achieved by the type liquid crystal aligning agent.

  According to the present invention, the above object and advantage of the present invention are as follows. Fourthly, the divalent organic group represented by the above formula (III-1) is represented by the following formulas (V-1) to (V-5). It is achieved by a vertical alignment type liquid crystal aligning agent characterized by containing at least one of divalent organic groups represented by each of the above.

(Here, R ^a represents a hydrogen atom or a monovalent organic group, R ^b represents an alkylene group having 1 to 20 carbon atoms, and a plurality of R ^a and R ^b may be the same or different. Well, p is an integer from 1 to 99, and q is an integer from 1 to 20.)

  According to the present invention, the above objects and advantages of the present invention are, fifthly, the polymer is represented by the amic acid repeating unit represented by the above formula (I-1) and the above formula (I-2). This is achieved by a vertical alignment type liquid crystal aligning agent characterized in that it is an imidized polymer in which the imide repeating unit accounts for 40 mol% or more with respect to the total of imide repeating units.

  According to the present invention, the above-mentioned objects and advantages of the present invention are sixthly the compound containing at least two epoxy groups in the molecule represented by each of the following formulas (VI-1) and (VI-2). This is achieved by a vertical alignment type liquid crystal aligning agent characterized by further containing 1 to 50 parts by weight of at least one epoxy group-containing compound selected from the group consisting of 100 parts by weight of the polymer.

(In the formula, s is an integer of 2 to 6, t is an integer of 1 to 4, R ^c is an s-valent organic group, and R ^d is a t-valent organic group.)

  According to the present invention, the object and advantage of the present invention are as follows. Seventh, a vertical alignment type liquid crystal display device comprising a vertical alignment type liquid crystal alignment film formed from the liquid crystal alignment agent of the present invention. Is achieved.

The vertical liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention is excellent in vertical alignment, has a high voltage holding characteristic, and provides a suitable liquid crystal alignment film having a good coating property to the substrate.
The liquid crystal display element of the present invention can be effectively used in various devices, and is suitable for display devices such as desk calculators, watches, table clocks, mobile phones, counting display boards, word processors, personal computers, and liquid crystal televisions. Can be used.

  Hereinafter, the present invention will be described in detail.

  The vertical alignment type liquid crystal aligning agent in the present invention (hereinafter also referred to as “liquid crystal aligning agent of the present invention”) is composed of a polymer containing an amic acid repeating unit and / or an imide repeating unit as described above. Among the above repeating units, a polymer containing an amic acid repeating unit (hereinafter also referred to as “polyamic acid polymer”) is obtained, for example, by reacting a tetracarboxylic dianhydride and a diamine compound in an organic solvent. . In addition, a polymer containing an imide repeating unit (hereinafter also referred to as “imidized polymer”) can be obtained by dehydrating and ring-closing the amic acid portion of the polyamic acid polymer. The polymer containing an amic acid repeating unit and / or an imide repeating unit used in the present invention may be a combined use of a polyamic acid polymer and an imidized polymer, and an amic acid repeating unit and an imide repeating unit in one polymer. It may be a polymer containing Hereafter, the manufacturing method of the polyamic acid polymer and imidized polymer which can be used for this invention is described.

[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride that can be used in the polyamic acid polymer and / or the polyimide polymer constituting the liquid crystal aligning agent in the present invention include, for example, butanetetracarboxylic dianhydride, the following formula (IV-10) ^: )

Here, R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, a halogen atom or a monovalent organic group.
Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4 , 4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,4-tricarboxycyclopentylacetic acid dianhydride, bicyclo [2,2,1] heptane- 2,3,5,6-tetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, tetracyclo [4,4,0,12,5,17,10] dodecane- 3,4,8,9-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, the following formula (IV-6 ⁰ )

Here, R ⁹ is a hydrogen atom or a monovalent organic group.
Dicarboxylic dianhydride represented by the formula: 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct -4-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, Aliphatic and alicyclic tetracarboxylic dianhydrides such as compounds represented by the following formulas (1) and (2);

(In the formula, R ¹⁰ and R ¹² represent a divalent organic group having an aromatic ring, R ¹¹ and R ¹³ represent a hydrogen atom or an alkyl group, and a plurality of R ¹¹ and R ¹³ are the same. But it may be different.)

  Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bi (3,4-Dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic acid Dianhydrides, bis (phthalic acid) phenylphosphine oxide dianhydrides, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anne) Hydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane -Aromatic tetra such as bis (anhydrotrimellitate), compounds represented by the following formulas (3) to (6) It can be mentioned carboxylic acid dianhydride. These may be used alone or in combination of two or more.

Examples of the cyclobutanetetracarboxylic dianhydride represented by the above formula (IV-1 ⁰ ) include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3. , 4-Cyclobutanetetracarboxylic dianhydride, 1,2-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic Acid dianhydride, 1,3-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1 2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride.

Examples of the dicarboxylic dianhydride represented by the above formula (IV-6 ⁰ ) include 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-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) ) -Naphtho [1,2-c] -furan-1,3- 1,3,3a, 4,5,9b-Hexahydro-7-ethyl-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, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3- Dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1, 3-dione may be mentioned.

Among these, cyclobutanetetracarboxylic dianhydride represented by the above formula (IV-1 ⁰ ), for example 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3 , 4-Cyclobutanetetracarboxylic dianhydride, 1,2-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic Acid dianhydride, 1,3-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1 , 2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride; bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride 1, , 3,4 cyclopentane tetracarboxylic dianhydride; 1,2,4,5-cyclohexane tetracarboxylic dianhydride; tetracarboxylic dianhydride example 1 represented by formula ^{(IV-6 0),} 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-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-Hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-Hexahydro-7-methyl 5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl- 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, 1,3,3a, 4,5,9b-hexahydro-8-ethyl- 5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8- Dimethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) At least one tetracarboxylic dianhydride selected from naphtho [1,2-c] -furan-1,3-dione; 2,3,5-tricarboxycyclopentylacetic dianhydride It is preferable to contain 50 mol% or more with respect to an anhydride, and 70 mol% or more is more preferable from a viewpoint of a characteristic improvement.

[Diamine compound]
Each of the above formulas (II-1), (II-2) and (III-1) represented by each of Q ¹ and Q ² in the repeating units represented by the above formulas (I-1) and (I-2) Is a diamine-derived group and corresponds to a residue obtained by removing two amino groups from the diamine.

In the formula (II-1), examples of the alkyl group having 10 to 20 carbon atoms represented by R ¹ include an n-decyl group, an n-dodecyl group, an n-pentadecyl group, an n-hexadecyl group, and an n-octadecyl group. Group, n-eicosyl group and the like. Examples of the monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms include cycloaliphatic skeletons derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, and cyclodecane; bridged fats such as norbornene and adamantane And monovalent organic groups having a cyclic skeleton; a steroid skeleton such as cholesterol and cholestanol. The monovalent organic group having the alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom. Examples of the monovalent organic group having a fluorine atom having 6 to 20 carbon atoms include linear alkyl groups having 6 to 20 carbon atoms such as n-hexyl group, n-octyl group and n-decyl group; A part or all of hydrogen atoms in an organic group such as an alicyclic hydrocarbon group having 6 to 20 carbon atoms such as a group or a cyclooctyl group; an aromatic hydrocarbon group having 6 to 20 carbon atoms such as a phenyl group or a biphenyl group Are groups substituted with a fluorine atom or a fluoroalkyl group. In the above formula (II-1), the group represented by X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, A methylene group, an alkylene group having 2 to 6 carbon atoms, or a phenylene group, and among these, particularly preferred are groups represented by —O—, —CO—, —COO—, and —OCO—.
Specific examples of the diamine having the group represented by the formula (II-1) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- Preferable examples include 2,4-diaminobenzene and compounds represented by the following formulas (7) to (21).

Next, in the above formula (II-2), examples of the divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms represented by R ² include cyclobutane, cyclopentane, cyclohexane, cyclodecane and the like. Examples thereof include divalent organic groups having an alicyclic skeleton derived from alkane; a bridged alicyclic skeleton such as norbornene and adamantane; and a steroid skeleton such as cholesterol and cholestanol. The divalent organic group having the alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom.
Specific examples of the diamine having a group represented by the above formula (II-2) include compounds represented by the following formulas (22) to (26).

  In the polyamic acid polymer and / or polyimide polymer of the present invention, the ratio of the divalent organic group represented by each of the above formulas (II-1) and (II-2) is, from the viewpoint of vertical orientation, Preferably it is 7 mol% or more with respect to the total amount of diamine, More preferably, it is 10 mol% or more.

Next, in the above formula (III-1), examples of the divalent organic group having an aromatic ring-containing skeleton represented by R ³ include a phenylene group, a biphenylene group, a naphthylene group, a methylenediphenylene group, and an oxydiphenylene. Groups. Arbitrary hydrogen in the aromatic ring in these aromatic ring-containing skeletons may be substituted by halogen or an alkyl group having 1 to 5 carbon atoms. Examples of the divalent organic group having an organosiloxane skeleton include a tetramethyldisiloxane group. Examples of the divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms include cycloaliphatic skeletons derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, and cyclodecane; bridged fats such as norbornene and adamantane And a divalent organic group having a cyclic skeleton. The divalent organic group having the alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom.

  Specific examples of the diamine having the group represented by the above formula (III-1) include 1,4-bis (aminomethyl) -bicyclo [2,2,1] heptane, 1,4-bis (aminopropyl). -Bicyclo [2,2,1] heptane, isophoronediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-bis (aminopropyl) cyclohexane, metaxylenediamine , P-xylenediamine, 3,3 ′-(hexamethyltrisiloxane-1,3-diyl) bis (propylamine), compounds represented by the following formulas (27) and (28), and the like are preferable. it can.

(In the above formula, n is an integer of 1 to 100.)
The ratio of the divalent organic group represented by the above formula (III-1) in the polyamic acid polymer and / or polyimide polymer of the present invention is based on the total amount of diamine from the viewpoint of improving the solubility of the polymer. Therefore, it is preferably 2% or more, more preferably 5% or more.

In the synthesis of the polyamic acid polymer and / or the polyimide polymer used in the present invention, other diamine compounds can be used in combination so as not to impair the effects of the present invention. Examples of other diamine compounds include p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, and 2 , 5-diethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl Ethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-di (trifluoromethyl) -4,4 '-Diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3, 3'-di (trifluoromethyl) -4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1 -(4'-aminophenyl) -1,3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoroprop 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1, 4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10 -Hydroanthracene, 2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetra Chloro-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, , 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) Phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl , Aromatic diamines such as 4- (4-n-heptylcyclohexyl) phenoxy-2,4-diaminobenzene;
Aliphatic diamines such as 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6 Methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1, 3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine, 5,6-diamino-1,3-dimethyl Luuracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3, A diamine having two primary amino groups and a nitrogen atom other than the primary amino group in the molecule, such as 6-diaminoacridine and bis (4-aminophenyl) phenylamine;
Examples thereof include compounds represented by the following formulas (29) and (30). These diamine compounds can be used alone or in combination of two or more.

(In the formula, y is an integer of 2 to 12, and z is an integer of 1 to 5.)
Among these, p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2,5-diethyl- 1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 4,4′-diaminodiphenylmethane, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2, 2′-di (trifluoromethyl) -4,4′-diaminobiphenyl, 2,2′-diethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3, 3′-diethyl-4,4′-diaminobiphenyl, 3,3′-di (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4′-diaminodiphenyl ether, 4,4′-di Preferred examples include minobenzophenone, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,6-diaminopyridine, 3,4-diaminopyridine and the like. be able to.

[Synthesis of polyamic acid]
The ratio of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is 0.2 to 2.2 based on 1 equivalent of amino group of diamine and tetracarboxylic dianhydride acid anhydride group. A ratio of 0 equivalent is preferable, and a ratio of 0.8 to 1.2 equivalent is more preferable. The polyamic acid synthesis reaction is preferably performed in an organic solvent under a temperature condition of −20 ° C. to 150 ° C., more preferably 0 to 100 ° C.

  Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of organic solvent used (α) is such that the total amount (β) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight based on the total amount of the reaction solution (α + β). It is preferable that

  In addition, the said organic solvent can use together the alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, etc. which are poor solvents of a polyamic acid in the range in which the polyamic acid to produce | generate does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol. , Ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, malon Acid diethyl, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i Propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. The reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a polyamic acid. The polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent once or several times.

[Synthesis of imidized polymer]
The imidized polymer constituting the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and ring-closing the polyamic acid. The imidized polymer used in the present invention may be partially dehydrated and ring-closed with an imidation rate of less than 100%. The “imidation ratio” here is a value expressed as a percentage of the ratio of repeating units having an imide ring or an isoimide ring in all repeating units of the polymer. The imidation ratio of the polyamic acid polymer and / or imidized polymer used in the present invention is preferably 40% or more, and more preferably 70% or more from the viewpoint of voltage holding characteristics. The polyamic acid is dehydrated and closed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. Depending on the method, a method of condensing and synthesizing is used.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease.

  On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, it is preferable to set it as 0.01-20 mol with respect to 1 mol of repeating units of polyamic acid. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. 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. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. In addition, as an organic solvent used for dehydration ring closure reaction, the same organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. And reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC. In addition, the imidized polymer can be purified by performing the same operation as in the polyamic acid purification method on the reaction solution thus obtained.

[End-modified polymer]
The polyamic acid / imidized polymer of the present invention may be a terminal-modified type having a controlled molecular weight. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified polymer can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing a polyamic acid. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-undecylamine. N-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. Can do. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

[Logarithmic viscosity of polymer]
The polyamic acid and / or imidized polymer thus obtained has a logarithmic viscosity (η _ln ) value of preferably 0.05 to 10 dl / g, more preferably 0.05 to 5 dl / g. .
The value of the logarithmic viscosity (η _ln ) in the present invention is determined by measuring the viscosity at 30 ° C. for a solution having a concentration of 0.5 g / 100 ml using N-methyl-2-pyrrolidone as a solvent. ).

[Imidation rate of polymer]
The imidized polymer obtained as described above has an imidation rate of preferably 50 to 100%, more preferably 65 to 100%, and even more preferably 75 to 100% from the viewpoint of improving voltage holding characteristics.
The imidation rate of the imidized polymer in the present invention is determined by ¹ H-NMR at room temperature using tetramethylsilane as a reference substance after drying the imidized polymer at 60 ° C. under reduced pressure and then dissolving it in deuterated dimethyl sulfoxide. Is obtained by the following equation (ii).
Imidization rate (%) = (1-A1 / A2 × α) × 100 −−−−−− (ii)
A1: Peak area derived from proton of NH group (10 ppm)
A2: Peak area derived from protons derived from aromatic rings (7 to 8 ppm)
α: Number ratio of protons derived from aromatic ring to one proton of NH group in polymer precursor (polyamic acid)

[Vertical alignment type liquid crystal alignment agent]
In order to obtain the liquid crystal aligning agent of the present invention, the polyamic acid polymer and / or imidized polymer is preferably dissolved and contained in an organic solvent. Moreover, the temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0 to 200 degreeC, More preferably, it is 20 to 60 degreeC.

  Examples of the organic solvent constituting the liquid crystal aligning agent of the present invention 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 ethoxypropionate, 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 Examples include ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate. Among these, a preferable solvent composition is a composition obtained by combining the above-mentioned solvents, so that no polymer is precipitated in the aligning agent, and the surface tension of the aligning agent is in the range of 30 to 40 mN / m. Composition.

The solid content concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a resin film that becomes a liquid crystal aligning film. When the solid content concentration is less than 1% by weight, the film thickness of the resin film is If the solid content concentration exceeds 10% by weight, the resin film becomes too thick to obtain a good liquid crystal alignment film. In addition, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics. The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 4 to 10% by weight, and thereby the solution viscosity is in the range of 10 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 2 to 5% by weight, and thereby the solution viscosity is in the range of 5 to 15 mPa · s.
The liquid crystal aligning agent of this invention may contain the epoxy group containing compound represented by following formula (VI-1) and (VI-2) within the range which does not impair the target physical property.

(In the formula, s is an integer of 2 to 6, t is an integer of 1 to 4, R ^c is an s-valent organic group, and R ^d is a t-valent organic group.)
Examples of such epoxy group-containing compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentylglycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-p-phenylenediamine, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, N, N, N ′, N′-tetraglycidyl-2,2′-di Methyl-4.4′-diaminobiphenyl, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] propane, N, N, N ′, N′-tetraglycidyl-4,4 '-Diaminodiphenylmethane, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,4-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,3-bis (N, N-di) Glycidylaminomethyl) benzene, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, and the like. The content of the epoxy group-containing compound is preferably 1 to 50 parts by weight, more preferably 5 to 45 parts by weight with respect to 100 parts by weight of the polymer.

  In addition, the liquid crystal aligning agent of the present invention may contain a functional silane-containing compound from the viewpoint of improving the adhesion to the substrate surface within a range that does not impair the intended physical properties. Examples of such functional silane-containing compounds 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-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl 1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl Acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- ( N, N-diglycidyl) aminopropyltrimethoxysilane It can be mentioned.

[Production of display element using liquid crystal aligning agent]
The liquid crystal display element using the vertical alignment type liquid crystal aligning agent of this invention can be manufactured, for example with the following method.

(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method, a printing method, an ink jet method, etc. Is heated to form a coating film. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. In applying the liquid crystal aligning agent, for example, a functional silane-containing compound or a functional titanium-containing compound can be applied in advance in order to further improve the adhesion between the substrate surface and the resin film. The heating temperature after application of the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The liquid crystal aligning agent of the present invention forms a resin film that becomes an alignment film by removing the organic solvent after coating. However, when imidization has not progressed completely, dehydration ring closure proceeds by further heating. It is also possible to obtain a more imidized resin film. The film thickness of the formed resin film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(2) Two substrates on which the vertical liquid crystal alignment film is formed as described above are manufactured, the two substrates are arranged to face each other with a gap (cell gap) therebetween, and the peripheral portions of the two substrates are sealed. A liquid crystal cell is formed by laminating using an agent, injecting and filling liquid crystal into the cell gap defined by the substrate surface and the sealing agent, and sealing the injection hole. And a liquid crystal display element is obtained by arrange | positioning a polarizing plate to the outer surface of a liquid crystal cell, ie, the transparent substrate side which comprises a liquid crystal cell.
Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.

Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable, for example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane. Type liquid crystal, cubane type liquid crystal and the like can be used. Further, for these liquid crystals, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, and chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck). Etc. can also be used. Furthermore, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can also be used.
Further, as a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an H film that absorbs iodine while sandwiching and stretching polyvinyl alcohol is sandwiched between cellulose acetate protective films. The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Various measurements in Examples and Comparative Examples were performed by the following methods.

(1) Evaluation of vertical alignment The vertical alignment type liquid crystal display device produced by the above method is visually observed from the vertical direction with respect to the liquid crystal display device when no voltage is applied under crossed Nicols and when an AC voltage of 8 V (peak-peak) is applied. When it was observed with a white display without a display failure such as light leakage, it was judged as “good”.
(2) Measurement of voltage holding ratio After applying a voltage of 5 V to a liquid crystal display element at 60 ° C. for 60 microseconds with a span of 16.7 microseconds, the voltage is held 16.7 milliseconds after the application release. The rate was measured.
(3) Solubility Evaluation of Polymer Viscosity 15 to 25 mPa · sec (solid content concentration 6.0 wt% to 8.0 wt%), solvent composition is 100, and γ-butyrolactone: N-methyl-2 -Pyrrolidone: butyl cellosolve = 40: (60-A): When prepared so as to be A (weight ratio), the presence or absence of suspension was visually observed, and even if the content A of butyl cellosolve, which is a poor solvent, was 30 or more The case where it was not suspended was defined as “good”.
(4) Printability evaluation About what was favorable in "the solubility evaluation of a polymer" of said (3), after apply | coating and baking by the printing method using the said preparation solution, the coating film was observed visually. A coating film having no repellency or coating unevenness was defined as “good”.

Synthesis Examples 1-25, Comparative Synthesis Examples 1-6
To N-methyl-2-pyrrolidone, the composition shown in Tables 1 and 2 was added in the order of diamine and tetracarboxylic dianhydride (shown as “acid anhydride” in the table) in this order, and the solid content concentration was 20% by weight. And reacted at 60 ° C. for 4 hours to obtain a polyamic acid polymer. The resulting polyamic acid polymer was added with pyridine and acetic anhydride in the number of moles shown in Table 1 with respect to the total amount of the polyacic acid polymer, and then heated to 110 ° C. for 4 hours for dehydration ring closure reaction. The obtained solution was reprecipitated with diethyl ether, and then recovered and dried under reduced pressure, whereby (A-1) to (A) having the logarithmic viscosities and imidization ratios shown in Table 1 and Table 2. -25) and (a-1) to (a-6) were obtained.

In Tables 1 and 2, for diamine compounds and acid anhydrides, the numbers in parentheses indicate the content ratio, and the meanings of the symbols in the tables are as follows.

<Diamine compound>
D-1: Diamine represented by formula (10) D-2: Diamine represented by formula (11) D-3: Diamine represented by formula (14) D-4: Formula (20) D-5: 1,4-bis (aminomethyl) -bicyclo [2.2.1] heptane D-6: 1,3-bis (aminomethyl) cyclohexane D-7: metaxylenediamine D-8: 3,3 ′-(tetramethyldisiloxane-1,3-diyl) bis (propylamine)
D-9: Diamine represented by the above formula (28) (average molecular weight 1,000)
D-10: p-phenylenediamine D-11: 4,4′-diaminodiphenylmethane D-12: 4,4′-diaminodiphenyl ether D-13: 2,2′-dimethyl-4,4′-diaminobiphenyl

<Tetracarboxylic dianhydride>
T-1: 1,2,4,5-cyclohexanetetracarboxylic dianhydride T-2: 2,3,5-tricarboxycyclopentylacetic acid dianhydride T-3: 1,2,3,4-cyclobutanetetra Carboxylic dianhydride 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 T-5: pyromellitic dianhydride

Example 1
The imidized polymer (A-1) obtained in Synthesis Example 1 was dissolved in a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solution (weight ratio 40/30/30) to obtain a polyethylene glycol diester. Glycidyl ether (molecular weight: about 400; additive A) was dissolved in 20 parts by weight with respect to 100 parts by weight of the polymer to obtain a solution having a solid content concentration of 6% by weight. When this solution was visually observed, a clear solution without turbidity was obtained, and it was confirmed that it showed good solubility. Subsequently, filtration was performed using a filter having a pore size of 0.2 μm to prepare the film forming composition of the present invention, and then evaluation of printability was performed. It was confirmed that it has sex.

Next, the film forming composition of the present invention was prepared in the same manner as described above except that the solid content concentration was 4%.
Next, the film-forming composition is applied by a spinner onto a transparent conductive film made of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm, and dried at 200 ° C. for 60 minutes. A 0.08 μm film was formed.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm to the outer edges of the pair of transparent electrodes / transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, the liquid crystal alignment film The adhesive was cured by overlapping and pressing so that the surfaces were opposed. Next, a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled between the substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and polarizing plates are formed on both sides of the substrate. Were laminated to prepare a liquid crystal display element. When the vertical alignment evaluation was performed on the obtained liquid crystal display element, it was good. Further, when the voltage holding ratio was measured, it was 99% or more, and good voltage holding characteristics were shown. The results are summarized in Table 3.

Examples 2-67, Comparative Examples 1-11
According to the formulations shown in Tables 3 and 4 below, a film forming composition having a solid content concentration of 6% was prepared in the same manner as in Example 1, and the solubility and printability were evaluated. Similarly, a film-forming composition having a solid content concentration of 4% was prepared to produce a liquid crystal display device. Then, vertical alignment evaluation and voltage holding ratio were performed. The results are shown in Tables 3, 4 and 5.

In Tables 3, 4 and 5, in the additives, the numbers in parentheses indicate the content ratios, and the meanings of the symbols in the tables are as follows.

<Additives>
Additive A: Polyethylene glycol diglycidyl ether (molecular weight about 400)
Additive B: 1,6-hexanediol diglycidyl ether additive C: N, N, N ′, N′-tetraglycidyl-2,2′-dimethyl-4,4′-diaminobiphenyl additive D: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane additive E: 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane additive F: N, N, N ′, N '-Tetraglycidyl-m-xylenediamine

Claims (7)

The polymer comprises at least one repeating unit of an amic acid repeating unit represented by the following formula (I-1) and an imide repeating unit represented by the following formula (I-2). Q ^{1 in the} formula and Q ² in the formula (I-2) are represented by the following formulas (II-1) and (II-2): A vertical alignment type liquid crystal aligning agent comprising at least one of divalent organic groups represented by (III-1).

(Here, P ¹ represents a tetravalent organic group constituting tetracarboxylic acid, and Q ¹ represents a divalent organic group constituting diamine.)

(Here, P ² represents a tetravalent organic group constituting tetracarboxylic acid, and Q ² represents a divalent organic group constituting diamine.)

(In the above formula, X ¹ represents a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, a methylene group, or an alkylene having 2 to 6 carbon atoms. R ¹ is a group having 10 to 20 carbon atoms, a monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent having a fluorine atom having 6 to 20 carbon atoms. R ² is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms or a divalent organic group having a fluorine atom having 5 to 30 carbon atoms.)

(In the above formula, X ² is a methylene group or an alkylene group having 2 to 20 carbon atoms, and R ³ is an aromatic ring-containing skeleton, an organosiloxane skeleton, —R— (O—C ₂ H ₄ ) _n —O. divalent organic group represented by -R- (R represents an alkylene radical, n is 1 to 100 of 2 to 5 carbon _{atoms), - R- (O-C} 3 H 6) n -O-R- A divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms (R is an alkylene group having 2 to 5 carbon atoms, n is 1 to 50), and And a plurality of X ² present in the formula may be the same or different.) P ¹ in the above formula (I-1) and P ² in (I-2) are at least one of tetravalent organic groups represented by the following formulas (IV-1) to (IV-6): The vertical alignment liquid crystal aligning agent of Claim 1 containing 1 type.

(Here, R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom or a monovalent organic group.) P ¹ in the above formula (I-1) and P ² in (I-2) are at least one of the tetravalent organic groups represented by each of the above formulas (IV-5) and (IV-6). one of the vertical alignment type liquid crystal aligning agent of claim 2 containing at least 50 mol% based on the total tetravalent organic group ^(P 1 ⁺ P ^2). The divalent organic group represented by the formula (III-1) contains at least one of the divalent organic groups represented by the following formulas (V-1) to (V-5). The vertical alignment type liquid crystal aligning agent in any one of Claims 1-3.

(Here, R ^a represents a hydrogen atom or a monovalent organic group, R ^b represents an alkylene group having 1 to 20 carbon atoms, and a plurality of R ^a and R ^b may be the same or different. Well, p is an integer from 1 to 99, and q is an integer from 1 to 20.) The imide repeating unit accounts for 40 mol% or more of the polymer based on the total of the amic acid repeating unit represented by the formula (I-1) and the imide repeating unit represented by the formula (I-2). It is an imidized polymer, The vertical alignment type liquid crystal aligning agent in any one of Claims 1-4. At least one epoxy group-containing compound selected from the group consisting of compounds containing at least two epoxy groups in the molecule represented by each of the following formulas (VI-1) and (VI-2) The vertical alignment liquid crystal aligning agent according to any one of claims 1 to 5, further containing 1 to 50 parts by weight with respect to parts.

(In the formula, s is an integer of 2 to 6, t is an integer of 1 to 4, R ^c is an s-valent organic group, and R ^d is a t-valent organic group.) A vertical alignment type liquid crystal display element comprising a vertical alignment type liquid crystal alignment film formed from the vertical alignment type liquid crystal alignment agent according to claim 1.