JP5130907B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a polyamic acid mainly composed of a tertiary amine and a diamine having an alkylene main chain as a main component, or a polymer containing a polyamic acid which is a derivative thereof and a polyimide, and a liquid crystal aligning agent formed using the polymer. The present invention also relates to a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film.

  Liquid crystal display elements are used in various liquid crystal display devices, such as monitors for notebook computers and desktop computers, viewfinders for video cameras, and projection displays. Recently, they are also used as display elements for televisions. It has become. Furthermore, it is also used as an optoelectronic-related element such as an optical printer head, an optical Fourier transform element, or a light valve. As a conventional liquid crystal display element, a display element using a nematic liquid crystal is mainly used. A TN (Twisted Nematic) type liquid crystal display element twisted by 90 degrees, and a STN (Super Twisted Nematic) type liquid crystal display element usually twisted by 180 degrees or more. A so-called TFT (Thin-film-transistor) type liquid crystal display element using a thin film transistor has been put into practical use.

  However, these liquid crystal display elements have a drawback in that the viewing angle at which an image can be properly viewed is narrow, and when viewed from an oblique direction, luminance and contrast are lowered, and luminance is inverted in a halftone. In recent years, with respect to the problem of viewing angle, a TN liquid crystal display element using an optical compensation film, an MVA (Multi-domain Vertical Alignment) liquid crystal display element using a technique of vertical alignment and protrusion structure, or a horizontal electric field method The IPS (In-Plane Switching) type liquid crystal display element has been improved, and this improved technique has been put into practical use (see, for example, Patent Documents 1 to 3).

  The development of the technology of the liquid crystal display element is achieved not only by simply improving these driving methods and element structures, but also by improving the components used in the liquid crystal display element. Among the components used in the liquid crystal display element, the liquid crystal alignment film is one of the important elements related to the display quality of the liquid crystal display element. Roles are becoming important year after year.

  Important characteristics required for the liquid crystal alignment film in order to improve the display quality of the liquid crystal display element include voltage holding ratio and residual DC. When the voltage holding ratio is low, the voltage applied to the liquid crystal during the frame period is lowered, and as a result, the luminance is lowered, which may hinder normal gradation display. On the other hand, when the residual DC is large, a so-called “afterimage” may occur in which an image to be erased remains even though the voltage is turned off after voltage application.

  In addition, contrast, which is a ratio of the luminance of white display to the luminance of black display, is used as one index indicating the performance of other liquid crystal display elements. In general, since the brightness of white display does not change greatly, the contrast greatly depends on the brightness of black display. Therefore, it is important to reduce the luminance of black display in order to increase the contrast.

  It is known that the contrast of liquid crystal display elements can be solved by using a liquid crystal alignment film with high uniaxial orientation, aligning liquid crystal molecules in the liquid crystal display elements more uniformly, and improving black display characteristics. (For example, refer to Patent Document 4) In other words, increasing the uniaxial orientation of the liquid crystal alignment film means that the retardation of the liquid crystal alignment film should be increased.

  As described above, in order to improve the display quality of the liquid crystal display element, a material having a high voltage holding ratio, a small residual DC, and a large retardation is required.

On the other hand, as a material for the liquid crystal aligning agent, polyamic acid having a divalent organic group containing phenylenediamino or a derivative thereof is known (for example, see Patent Document 5). There is room for further study from the viewpoint of further improvement.
Japanese Examined Patent Publication No. 63-21907 JP-A-6-160878 JP-A-9-15650 JP 2005-258397 A International Publication No. 2004/053583 Pamphlet

  An object of the present invention is to use a polyamic acid that can form a liquid crystal alignment film having a high voltage holding ratio, a low residual DC, and a large retardation, a polyamic acid that is a derivative thereof, a polyimide polymer, and the polymer. And a liquid crystal display element that has the liquid crystal alignment film and has excellent contrast and does not cause image sticking.

  The present inventors have intensively studied to solve the above-mentioned problems, and by introducing an alkylene structure into diamine, which is a polymer raw material, the liquid crystal alignment film made of the polymer has more liquid crystal molecules in the liquid crystal display element. As a result, it was found that a liquid crystal display element using the liquid crystal alignment film has a large retardation. Further, it has been found that a liquid crystal alignment film provides a high voltage holding ratio and low residual DC when used in a liquid crystal display element by introducing a tertiary amine into the diamine and using a polymer incorporating the diamine. It was.

  The present invention comprises the following.

[1] In a liquid crystal aligning agent containing polyamic acid or a derivative thereof which is a reaction product of tetracarboxylic dianhydride and diamine,
The diamine is a liquid crystal aligning agent containing a diamine represented by the following general formula (1).

In general formula (1), R ¹ independently represents a monovalent organic group, R ² independently represents a monovalent group, and Z represents a divalent group containing an alkylene having 1 to 5 carbon atoms. Represent.

[2] Liquid crystal alignment according to [1], wherein R ¹ is independently alkyl having 1 to 3 carbons, and R ² is independently hydrogen, alkyl having 1 to 3 carbons, fluorine, chlorine, or bromine. Agent.

[3] The liquid crystal aligning agent according to [1] or [2], wherein the diamine represented by the general formula (1) has an amino at each para position with respect to the NZN main chain in phenyl at both ends.

[4] The diamine represented by the general formula (1) is represented by the following structural formulas 239 to 253 and 258 to 2.
62. The liquid crystal aligning agent according to [3], which is one or more selected from the group consisting of 62.

[5] The liquid crystal alignment according to any one of [1] to [4], wherein the tetracarboxylic dianhydride is one or more selected from the following structural formulas 500, 505 to 508, 511, 515, and 517. Agent.

[6] The liquid crystal aligning agent according to [5], wherein the tetracarboxylic dianhydride is one or both of the structural formulas 500 and 511.

[7] The liquid crystal aligning agent according to any one of [1] to [6], wherein the diamine further includes a diamine represented by the following general formula (2).

In the general formula (2), R ³ is substituted not including a good good diacetic above also represent a divalent organic group.

[8] The liquid crystal aligning agent according to [7], wherein the diamine represented by the general formula (2) includes a diamine represented by the following general formulas (3) to (5).

  In General Formula (3), Y represents a divalent group containing one or more alkylene having 1 to 5 carbon atoms, oxygen, and sulfur.

In General Formula (4), X ¹ independently represents methylene or oxygen, and X ² represents C 1-8 alkylene which may have methyl or CF ₃ as a substituent.

In general formula (5), X ¹ independently represents alkylene having 1 to 6 carbons or oxygen, X ³ represents a single bond or alkylene having 1 to 3 carbons, and ring T is 1,4-phenylene or 1,4-cyclohexylene, R ⁴ is hydrogen or alkyl having 1 to 30 carbons (provided that any methylene in the alkyl having 2 to 30 carbons is independently oxygen, —CH═ CH— or —C≡C— may be substituted, but in the alkyl, oxygen is not adjacent.), H represents 0 or 1.

[9] The liquid crystal aligning agent according to [8], wherein in the general formulas (3) to (5), two amino positions are para to Y or X ¹ .

[10] The diamine represented by the general formula (3) is one or more selected from the group consisting of the following structural formulas 301 to 304, 306, 307, and 313, and the diamine represented by the general formula (4) is One or more selected from the group consisting of structural formulas 360, 364, 365, 367, and 372, and the diamine represented by general formula (5) is selected from the group consisting of the following structural formulas 381, 384, 390, and 398 [9] The liquid crystal aligning agent according to [9].

[11] In the diamine, the content of the diamine represented by the general formula (1) is 20 to 99 mol%, and the content of the diamine represented by the general formula (2) is 1 to 80 mol%. [8] The liquid crystal aligning agent as described in any one of [10].

[12] Polyamic acid which is a reaction product of tetracarboxylic dianhydride A and diamine A or a derivative A thereof, and polyamic acid which is a reaction product of tetracarboxylic dianhydride B and diamine B or a derivative thereof In the liquid crystal aligning agent containing B,
The diamine A includes a diamine represented by the general formula (1),
The diamine B is a liquid crystal aligning agent not containing the diamine represented by the general formula (1).

[13] In General Formula (1), R ¹ is independently alkyl having 1 to 3 carbon atoms, and R ² is independently hydrogen, alkyl having 1 to 3 carbon atoms, fluorine, chlorine, or bromine. The liquid crystal aligning agent as described in [12].

[14] The liquid crystal aligning agent according to [12] or [13], wherein the diamine represented by the general formula (1) has an amino at each para position with respect to the NZN main chain in phenyl at both ends.

[15] The liquid crystal aligning agent according to [14], wherein the diamine represented by the general formula (1) is one or more selected from the group consisting of the structural formulas 239 to 253 and 258 to 262.

[16] The liquid crystal aligning agent according to any one of [12] to [15], wherein the diamine B includes a diamine represented by the general formula (2).

[17] The liquid crystal aligning agent according to [16], wherein the general formula (2) diamine includes a diamine represented by the general formulas (3) to (5).

[18] The liquid crystal aligning agent according to [17], wherein in the general formulas (3) to (5), two amino positions are para to Y or X ¹ .

[19] The diamine represented by the general formula (3) is one or more selected from the group consisting of the structural formulas 301 to 304, 306, 307, and 313, and the diamine represented by the general formula (4) One or more selected from the group consisting of structural formulas 360, 364, 365, 367, and 372, and the diamine represented by general formula (5) is selected from the group consisting of structural formulas 381, 384, 390, and 398. [18] The liquid crystal aligning agent as described in [18].

[20] The tetracarboxylic dianhydride A and the tetracarboxylic dianhydride B are one or more selected from the structural formulas 500, 505 to 508, 511, 515, and 517 of [12] to [19] The liquid crystal aligning agent as described in any one.

[21] The liquid crystal aligning agent according to [20], wherein the tetracarboxylic dianhydride A and the tetracarboxylic dianhydride B are one or both of the structural formulas 500 and 511.

[22] The liquid crystal aligning agent according to any one of [1] to [21], further including an epoxy compound.

[23] The liquid crystal aligning agent according to [22], wherein the epoxy compound is one or more selected from the group consisting of the following structural formulas (E1) to (E3), (E5) and the following general formula (E4). .

In general formula (E4), n represents the integer of 0-10.

[24] The liquid crystal aligning agent according to [22] or [23], wherein the epoxy compound is contained in an amount of 0.1 to 40% by weight based on the total amount of the polyamic acid or a derivative thereof.

[25] A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of [1] to [24].

[26] A pair of substrates, a liquid crystal layer containing liquid crystal molecules and formed between the pair of substrates, an electrode for applying a voltage to the liquid crystal layer, and a liquid crystal alignment for aligning the liquid crystal molecules in a predetermined direction A liquid crystal display element having a film, wherein the liquid crystal alignment film is a liquid crystal alignment film according to [25].

[27] The liquid crystal display element according to [26], wherein the electrode is a liquid crystal display element for a horizontal electric field mode in which a voltage is applied to the liquid crystal layer in a horizontal direction with respect to the surface of the substrate.

[28] The liquid crystal display element according to [26], wherein the electrode is a vertical electric field mode liquid crystal display element that applies a voltage to the liquid crystal layer in a direction perpendicular to the surface of the substrate.

[29] In a polymer which is a reaction product of tetracarboxylic dianhydride and diamine,
The diamine is a polymer containing the diamine represented by the general formula (1) and the diamine represented by the general formula (2).

[30] In General Formula (1), R ¹ is independently alkyl having 1 to 3 carbon atoms, and R ² is independently hydrogen, alkyl having 1 to 3 carbon atoms, fluorine, chlorine, or bromine. [29] The polymer described.

[31] The polymer according to [29] or [30], wherein the diamine represented by the general formula (1) has an amino at each para position relative to the NZN main chain in the phenyl at both ends.

[32] The polymer according to [31], wherein the diamine represented by the general formula (1) is one or more selected from the group consisting of the structural formulas 239 to 253 and 258 to 262.

[33] The polymer according to [32], wherein the diamine represented by the general formula (1) is the structural formula 240.

[34] The polymer according to any one of [29] to [33], wherein the diamine represented by the general formula (2) includes the diamine represented by the general formulas (3) to (5).

[35] The polymer according to [34], wherein in the general formulas (3) to (5), the two amino positions are para to Y or X ¹ .

[36] The diamine represented by the general formula (3) is one or more selected from the group consisting of the structural formulas 301 to 304, 306, 307, and 313, and the diamine represented by the general formula (4) One or more selected from the group consisting of structural formulas 360, 364, 365, 367, and 372, and the diamine represented by general formula (5) is selected from the group consisting of structural formulas 381, 384, 390, and 398. [35] The polymer according to [35].

[37] The diamine represented by the general formula (3) is one or both of the structural formulas 301 and 306, the diamine represented by the general formula (4) is the structural formula 364, and the general formula (5). The polymer according to [36], wherein the diamine represented by the formula is the structural formula 381.

[38] The polymer according to any one of [29] to [37], wherein the tetracarboxylic dianhydride is one or more selected from the structural formulas 500, 505 to 508, 511, 515, and 517. .

[39] The polymer according to [38], wherein the tetracarboxylic dianhydride is one or both of the structural formulas 500 and 511.

  According to the present invention, a liquid crystal display device having a particularly excellent contrast, a high voltage holding ratio and a reduction in residual DC, a so-called accumulated charge reduction liquid crystal display device that does not cause image sticking, and a liquid crystal alignment film therefor are formed. The polymer and the liquid crystal aligning agent which can be provided can be provided.

  The liquid crystal aligning agent of this invention contains the polyamic acid which is a reaction product of tetracarboxylic dianhydride and diamine, or its derivative (s). The polyamic acid derivative is a component that dissolves in a solvent when the liquid crystal aligning agent described later contains a solvent. When the liquid crystal aligning agent is used as a liquid crystal aligning film described later, the main component is polyimide. It is a component that can form a liquid crystal alignment film. Examples of such polyamic acid derivatives include soluble polyimides, polyamic acid esters, polyamic acid amides, and the like. More specifically, 1) polyimide in which all amino acids and carboxyls of polyamic acid are subjected to a dehydration ring-closing reaction, 2) Partially dehydrated ring-closing partial polyimide, 3) Polyamic acid ester in which carboxyl of polyamic acid is converted to ester, 4) Part of acid dianhydride contained in tetracarboxylic dianhydride compound is organic dicarboxylic Examples thereof include polyamic acid-polyamide copolymers obtained by reacting with an acid, and 5) polyamideimide obtained by subjecting a part or all of the polyamic acid-polyamide copolymer to a dehydration ring-closing reaction. The polyamic acid or derivative thereof may be a single compound or two or more.

  The diamine includes a diamine represented by the following general formula (1). One kind of compound may be sufficient as the diamine represented by General formula (1), and a 2 or more types of compound may be sufficient as it.

In the general formula (1), R ¹ independently represents a monovalent organic group, R ² independently represents a monovalent group, and Z represents a divalent group containing an alkylene having 1 to 5 carbon atoms. Represents.

Wherein the R ¹ is can be used various monovalent organic group, R ¹ is preferably alkyl having 1 to 3 carbon atoms independently. Wherein the R ^2, can be used various monovalent radicals, hydrogen R ² are each independently alkyl of 1 to 3 carbon atoms, fluorine, chlorine, or be a bromine preferred.

  As the Z, divalent groups having various structures including alkylene having 1 to 5 carbon atoms can be used. Z may be an alkylene having 1 to 5 carbon atoms, or a group having an alkylene having 1 to 5 carbon atoms and another divalent group. The alkylene may be one kind, or two or more kinds (but not discontinuous). Examples of such Z include a divalent group represented by the following general formula (8).

In the general formula (8), R ⁸ independently represents hydrogen or alkyl having 1 to 3 carbon atoms, and n represents an integer of 1 to 5. The alkylene is preferably an alkylene having 2 to 5 carbon atoms.

The diamine represented by the general formula (1) has an amino in each of the phenyls at both ends. These amino positions may be in any of ortho, meta, and para positions with respect to the NZN main chain, but from the viewpoint of improving the black display characteristics at the time of voltage application in the liquid crystal display element. Both are preferably in the para position.

  In the present invention, examples of the diamine represented by the general formula (1) include the following compounds.

  More preferable examples of the diamine represented by the general formula (1) include the following compounds.

  More preferable examples of the diamine represented by the general formula (1) include the compounds represented by the above structural formulas 239 to 253 and 258 to 262, and even more preferable examples of the diamine represented by the general formula (1) include the above structural formula. The compounds of 240-243 and 259-262 are mentioned.

  The diamine may contain only the diamine represented by the general formula (1), or may further contain another diamine represented by the following general formula (2). One kind of compound may be sufficient as the diamine represented by General formula (2), and a 2 or more types of compound may be sufficient as it.

In the general formula (2), R ³ is substituted not including a good good diacetic above also represent a divalent organic group.

  The diamine represented by the general formula (2) includes various diamines, and preferably diamines represented by the following general formulas (3) to (6).

  In General Formula (3), Y represents a divalent group containing one or more alkylene having 1 to 5 carbon atoms, oxygen, and sulfur.

In General Formula (4), X ¹ independently represents methylene or oxygen, and X ² represents C 1-8 alkylene which may have methyl or CF ₃ as a substituent.

In general formula (5), X ¹ independently represents alkylene having 1 to 6 carbons or oxygen, X ³ represents a single bond or alkylene having 1 to 3 carbons, and ring T is 1,4-phenylene or 1,4-cyclohexylene, R ⁴ represents hydrogen or alkyl having 1 to 30 carbon atoms, and h represents 0 or 1. However, in the alkyl of R ⁴ , any methylene in the alkyl having 2 to 30 carbon atoms may be independently replaced by oxygen, —CH═CH— or —C≡C—. Are not next to each other.

In general formula (6), R ⁵ represents hydrogen or a monovalent group. Although various organic groups can be used for the monovalent group, it is preferably a hydrocarbon group having 1 to 30 carbon atoms. This hydrocarbon group is preferably a group having a divalent hydrocarbon group such as alkylene, cycloalkylene, or arylene, and alkyl.

In the general formulas (3) to (5), the positions of the two amino groups bonded to phenyl at both ends may be any of ortho, meta, and para with respect to Y or X ¹ . From the viewpoint of improving the black display characteristics at the time of voltage application, it is preferably in the para position with respect to Y or X ¹ .

  In the general formula (6), the position of the two aminos bonded to the terminal phenyl may be any of ortho, meta, and para, but a viewpoint of developing a relatively large pretilt angle in the liquid crystal display device. Therefore, it is preferable that they are in the meta position.

  Examples of the diamine represented by the general formula (3) include the following compounds.

  Examples of the diamine represented by the more general formula (3) include the following compounds.

  More preferable examples of the diamine represented by the general formula (3) include the compounds represented by the structural formulas 301 to 307 and 311 to 319. The diamine represented by the more preferable general formula (3) is the structural formula 301 to Examples include 304, 306, 307, and 313 compounds.

  Examples of the diamine represented by the general formula (4) include the following compounds.

  Examples of the diamine represented by the more general formula (4) include the following compounds.

  More preferable examples of the diamine represented by the general formula (4) include the compounds represented by the structural formulas 360, 364 to 367, and 372. The diamine represented by the more preferable general formula (4) is the structural formula 360 described above. 364, 365, 367, and 372.

  Examples of the diamine represented by the general formula (5) include the following compounds.

  Examples of the diamine represented by the more general formula (5) include the following compounds.

  More preferable examples of the diamine represented by the general formula (5) include the compounds represented by the structural formulas 381, 382, 384, 390, and 398, and the diamine represented by the more preferable general formula (5) includes the structure described above. Compounds of formulas 381, 384, 390, and 398 are included.

  Examples of the diamine represented by the general formula (6) include the following compounds.

  Examples of the diamine represented by the more general formula (6) include the following compounds.

  More preferable examples of the diamine represented by the general formula (6) include the compounds represented by the structural formulas 438, 443, 447, and 449 to 451.

  In the present invention, other diamines other than the diamines represented by the general formulas (1) and (2) can be further used as the diamine. Examples of such other diamines include diamines represented by the following general formula (9a) or (9b), and siloxane-based diamines having a siloxane bond.

In general formulas (9a) and (9b), Q is oxygen, sulfur, sulfonyl, an arylene having 6 to 20 carbon atoms that may have a substituent, or 3 to 20 carbon atoms that may have a substituent. Of cycloalkylene, or imino which may have a substituent. Examples of the substituent that the arylene, cycloalkylene, and imino may have independently include monovalent organic groups such as alkyl having 1 to 3 carbon atoms, fluorine, chlorine, and bromine. The arylene includes 1,4-phenylene, and the cycloalkylene includes 1,4-cyclohexylene. R ¹ , R ² and R ⁸ in the general formulas (9a) and (9b) are the same as those in the general formulas (1) and (8). Examples of the diamine represented by the general formula (9a) or (9b) include the following compounds.

  The diamine represented by the general formula (9a) or (9b) has an amino in each of the phenyls at both ends. These amino positions may be in any of ortho, meta, and para positions with respect to the divalent organic group, but from the viewpoint of improving the black display characteristics at the time of voltage application in the liquid crystal display element. Is also preferably in the para position.

  Preferred examples of the diamine represented by the general formula (9a) or (9b) include the following compounds.

  Although the said siloxane type diamine is not specifically limited, The diamine represented by General formula (7) can be used preferably in this invention.

In the general formula (7), R ²² and R ²³ independently represent alkyl having 1 to 3 carbon atoms or phenyl, R ²¹ independently represents methylene, phenylene or alkyl-substituted phenylene, and x is independently Represents an integer of 1 to 6, and y represents an integer of 1 to 10.

  In the present invention, the kind of the diamine used can be determined according to the electric field system in the liquid crystal display element. The horizontal electric field method and the vertical electric field method are known as the electric field method of the liquid crystal display element, but the liquid crystal display element of the horizontal electric field method needs to have a so-called low pretilt angle that expresses a small pretilt angle. If it is diamine represented by General formula (2), the diamine represented by General formula (3) and (4) is mainly used.

  In the present invention, a liquid crystal display device obtained from a liquid crystal aligning agent using 100 mol% of the diamine represented by the general formula (1) as the diamine has characteristics of large contrast, low residual DC, and low pretilt angle. Therefore, it is effective as a horizontal electric field type liquid crystal alignment film. For a vertical electric field type liquid crystal display element that requires a relatively large pretilt angle, it is necessary to use a diamine having a so-called side chain that exhibits a relatively large pretilt angle. Examples of the diamine having such a side chain include the diamines represented by the general formulas (5) and (6) as long as the diamine is represented by the general formula (2). Mixing of a polyamic acid obtained by using a diamine having a chain or a derivative thereof with another polyamic acid or a derivative thereof (for example, having a low pretilt angle), or a combination of a diamine having a side chain and a diamine having a low pretilt angle. Polymerization is required.

  Furthermore, in the polymer in the present invention, the diamine represented by the general formula (1) is used in combination with one or more diamines represented by the general formula (2). At this time, the content of the diamine represented by the general formula (1) in the diamine is preferably 20 mol% or more from the viewpoint of clearly reducing the residual DC in the liquid crystal display element. When the content of the diamine represented by the general formula (1) is less than 20 mol%, the effect of reducing residual DC may be weakened, and the effect of afterimage may not be seen.

  Further, in the lateral electric field type liquid crystal display element, it is possible to use one or more diamines represented by the general formulas (3) and (4) in combination with the diamine represented by the general formula (1). This is preferable from the viewpoint of improving the black display characteristics. Furthermore, the use of these diamines is very effective for the transverse electric field system because of the low pretilt angle. The more the diamine represented by the general formulas (3) and (4) in the diamine, the better the voltage holding ratio in the liquid crystal display device, but considering the reduction of residual DC, the content is 1 mol% to 80%. It is preferably in the range of mol%.

In addition, in the TN method, the OCB method, and the VA method, which are vertical electric field methods, it is essential to develop a relatively large pretilt angle. In this case, it is necessary to use one or more diamines represented by the general formulas (5) and (6) with side chains in combination with the diamine represented by the general formula (1). By controlling the types and proportions of these diamines, a predetermined pretilt angle can be expressed, but considering the residual DC reduction, the content is preferably in the range of 1 mol% to 80 mol%. . By using the diamines represented by the general formulas (5) and (6) in combination, the liquid crystal display element to which the obtained polymer is applied becomes a vertical electric field type liquid crystal display element with further improved voltage holding ratio. sell.

  Moreover, when it contains further diamine other than said general formula (1)-(6), the content rate of other diamine is 30 mol% or less of the whole diamine, and the obtained polymer is used. In the applied liquid crystal display element, it is preferable from the viewpoint of sufficiently exhibiting the effects of reducing residual DC and improving black display characteristics.

  As the tetracarboxylic dianhydride, unless the effect of the present invention is impaired, aromatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, etc. One or more of various tetracarboxylic dianhydrides can be used.

  Examples of the tetracarboxylic dianhydride that can be used in the present invention include the following compounds.

  The tetracarboxylic dianhydride is preferably a compound of the structural formulas 500, 505 to 508, 511, 515, and 517, and more preferably a compound of the structural formulas 500 and 511.

  The molecular weight of the polyamic acid or a derivative thereof is, for example, a weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) method, preferably 10,000 to 500,000, more preferably 20,000 to 200. , 000.

  The polyamic acid or derivative thereof can be produced in the same manner as a known polyamic acid or derivative thereof used for forming a polyimide film, except that the tetracarboxylic dianhydride and diamine described above are used. For example, in a reaction vessel equipped with a raw material inlet, a nitrogen inlet, a thermometer, a stirrer and a condenser, with one or more diamines represented by the general formulas (1) and (2) to (6), Is charged with one or more diamines selected from other diamines and, if necessary, the desired amount of monoamines.

  Next, one or more of a solvent (for example, N-methyl-2-pyrrolidone and dimethylformamide which are amide polar solvents) and tetracarboxylic dianhydride, and a carboxylic anhydride as necessary are added. . At this time, it is preferable that the total charge amount of tetracarboxylic dianhydride is approximately equal to the total number of moles of diamine (molar ratio of about 0.9 to 1.1).

The polyamic acid or derivative thereof includes a structure formed by a reaction between a diamine represented by the general formula (1) and a tetracarboxylic dianhydride, and further includes a diamine and a tetra represented by the general formula (2). It may contain structures formed by reaction with carboxylic dianhydrides. Examples of the reaction product structure of the diamine represented by the general formula (1) and the tetracarboxylic dianhydride include structures represented by the following general formulas (10) and (11). Examples of the reaction product structure of the diamine and tetracarboxylic dianhydride represented by the formula include structures represented by the following general formulas (12) and (13). In the general formulas (10) to (13), R ¹⁰ represents a tetravalent organic group derived from tetracarboxylic dianhydride, R ¹ and R ² are the same as those in the general formula (1), and R ³ is the same as in the general formula (2).

  The structure represented by the general formulas (10) to (13) in the polyamic acid or a derivative thereof can be specified by an ordinary technique in specifying the structure of the polymer, and more specifically, specified by IR or NMR. can do.

  More specifically, the polyamic acid or derivative thereof in the present invention can be identified by precipitating with a large amount of a poor solvent, completely separating the solid content and the solvent by filtration or the like, and analyzing by IR or NMR. Furthermore, after decomposing solid polyamic acid or its derivative with an aqueous solution of strong alkali such as KOH or NaOH, it is extracted with an organic solvent, and analyzed by GC, HPLC or GC-MS, and used monomers. Can be identified.

  The liquid crystal aligning agent of this invention may further contain other components other than the said polyamic acid or its derivative (s). Other components may be one kind or two or more kinds.

  For example, the liquid crystal aligning agent of this invention may contain the epoxy compound further from a viewpoint of improving the durability in a liquid crystal aligning film, for example. The epoxy compound is not particularly limited as long as it has an epoxy, but a compound having two or more oxiranes is preferable. The epoxy compound may be a kind of compound or two or more kinds of compounds.

  In the present invention, the content of the epoxy compound in the liquid crystal aligning agent is not particularly limited, but the liquid crystal aligning film formed from the liquid crystal aligning agent is 0.1 to 40% by weight with respect to the liquid crystal aligning agent. It is preferable from the viewpoint of improving durability such that the film is hardly scraped by rubbing treatment, and is more preferably 0.2 to 30% by weight.

  Examples of the epoxy compound include a bisphenol A type epoxy compound, a glycidyl ester type epoxy compound, an alicyclic epoxy compound, a polymer of a monomer having an oxirane, a copolymer of a monomer having an oxirane and another monomer, and the following structure: Examples thereof include compounds represented by formulas (E1) to (E3) and (E5), and compounds represented by the following general formula (E4).

  In general formula (E4), n represents the integer of 0-10.

More specifically, examples of the epoxy compound include trade names “Epicoat 807”, “Epicoat 815”, “Epicoat 825”, and “Epicoat 827”.

  As the compound represented by the general formula (E4), trade names “Epicoat 828”, “Epicoat 190P”, “Epicoat 191P” (manufactured by Yuka Shell Epoxy Co., Ltd.), trade names “Epicoat 1004”, “ Epicoat 1256 ”(manufactured by Japan Epoxy Resin Co., Ltd.), and trade name“ Araldite CY177 ”.

  Examples of the compound represented by the structural formula (E1) include trade name “Araldite CY184” (manufactured by Ciba Geigy Japan Ltd.).

  Examples of the compound represented by the structural formula (E2) include trade names “Celoxide 2021P” and “EHPE-3150” (manufactured by Daicel Chemical Industries, Ltd.).

  Examples of the compound represented by the structural formula (E3) include trade name “Techmore VG3101L” (manufactured by Mitsui Chemicals, Inc.).

  Examples of the compound represented by the structural formula (E5) include “4,4′-methylenebis (N, N-diglycidylaniline)” (manufactured by Sigma-Aldrich).

  Among these, the said epoxy compound is a compound represented by "Epicoat 828" which is a compound (mixture of the compound of n = 0-4) represented by general formula (E4), and structural formula (E1). Araldite CY184 "(manufactured by Ciba-Geigy Japan), trade name" Celoxide 2021P "(manufactured by Daicel Chemical Industries), a compound represented by structural formula (E2), compound represented by structural formula (E3) "Techmore VG3101L" (manufactured by Mitsui Chemicals) and the compound "4,4'-methylenebis (N, N-diglycidylaniline)" represented by the structural formula (E5) (Sigma-Aldrich) From the viewpoint of improving the transparency and flatness of the liquid crystal alignment film.

  Further, examples of the epoxy compound include glycidyl ether, glycidyl ester, glycidyl amine, epoxy group-containing acrylic resin, glycidyl amide, glycidyl isocyanurate, chain aliphatic epoxy compound, and cyclic aliphatic epoxy compound. In addition, an epoxy compound means the compound which has an epoxy group, and an epoxy resin means resin which has an epoxy group.

  Examples of the glycidyl ether include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, bisphenol type epoxy compounds, hydrogenated bisphenol-A type epoxy compounds, hydrogenated bisphenol-F type epoxy compounds, and hydrogenated compounds. Bisphenol-S type epoxy compound, hydrogenated bisphenol type epoxy compound, brominated bisphenol-A type epoxy compound, brominated bisphenol-F type epoxy compound, phenol novolac type epoxy compound, cresol novolak type epoxy compound, brominated phenol novolak type epoxy Compounds, brominated cresol novolac epoxy compounds, bisphenol A novolac epoxy compounds, naphthalene skeleton-containing epoxy compounds, aromatic Polyglycidyl ether compounds, dicyclopentadiene phenol type epoxy compound, alicyclic diglycidyl ether compounds, aliphatic polyglycidyl ether compound, a polysulfide-type diglycidyl ether compound, and biphenol type epoxy compound.

  Examples of the glycidyl ester include diglycidyl ester compounds and glycidyl ester epoxy compounds.

  Examples of the glycidylamine include polyglycidylamine compounds.

  Examples of the epoxy group-containing acrylic compound include homopolymers and copolymers of monomers having oxiranyl.

  Examples of the glycidyl amide include glycidyl amide type epoxy compounds.

  Examples of the chain aliphatic epoxy compound include a compound containing an epoxy group obtained by oxidizing a carbon-carbon double bond of an alkene compound.

  Examples of the cycloaliphatic epoxy compound include a compound containing an epoxy group obtained by oxidizing a carbon-carbon double bond of a cycloalkene compound.

  Examples of the bisphenol A type epoxy compound include 828, 1001, 1002, 1003, 1004, 1007, and 1010 (all manufactured by Japan Epoxy Resin), Epototo YD-128 (manufactured by Tohto Kasei Co., Ltd.), DER-331, and DER-332. , DER-324 (all manufactured by Dow Chemical Company), Epicron 840, Epicron 850, Epicron 1050 (all manufactured by Dainippon Ink), Epomic R-140, Epomic R-301, and Epomic R-304 (all Mitsui) Chemical).

  Examples of the bisphenol F-type epoxy compound include 806, 807, 4004P (all manufactured by Japan Epoxy Resin), Epototo YDF-170, Epototo YDF-175S, Epototo YDF-2001 (all manufactured by Toto Kasei Co., Ltd.), DER-354. (Dow Chemical Co., Ltd.), Epicron 830, and Epicron 835 (all manufactured by Dainippon Ink) are listed.

  Examples of the bisphenol type epoxy compound include epoxidized products of 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane.

  Examples of the hydrogenated bisphenol-A type epoxy compound include Santo Tote ST-3000 (manufactured by Toto Kasei Co., Ltd.), Rica Resin HBE-100 (manufactured by Shin Nippon Chemical Co., Ltd.), and Denacol EX-252 (manufactured by Nagase ChemteX Corporation). .

  Examples of the hydrogenated bisphenol type epoxy compound include epoxidized products of hydrogenated 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane.

  Examples of the brominated bisphenol-A type epoxy compound include 5050, 5051 (all manufactured by Japan Epoxy Resin), Epototo YDB-360, Epototo YDB-400 (all manufactured by Toto Kasei Co., Ltd.), DER-530, DER-538. (All manufactured by Dow Chemical Co., Ltd.), Epicron 152, and Epicron 153 (all manufactured by Dainippon Ink).

  Examples of the phenol novolac type epoxy compound include 152, 154 (all manufactured by Japan Epoxy Resin), YDPN-638 (manufactured by Tohto Kasei Co., Ltd.), DEN431, DEN438 (all manufactured by Dow Chemical Co., Ltd.), Epicron N-770 ( Dainippon Ink & Chemicals, Inc.), EPPN-201, and EPPN-202 (all manufactured by Nippon Kayaku Co., Ltd.).

  Examples of the cresol novolac type epoxy compound include 180S75 (manufactured by Japan Epoxy Resin), YDCN-701, YDCN-702 (all manufactured by Tohto Kasei Co., Ltd.), Epicron N-665, Epicron N-695 (all Dainippon Ink and Chemicals). Kogyo Co., Ltd.), EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1020, EOCN-1025, and EOCN-1027 (all manufactured by Nippon Kayaku Co., Ltd.).

  Examples of the bisphenol A novolac type epoxy compound include 157S70 (manufactured by Japan Epoxy Resin Co., Ltd.) and Epicron N-880 (manufactured by Dainippon Ink & Chemicals, Inc.).

  Examples of the naphthalene skeleton-containing epoxy compound include Epicron HP-4032, Epicron HP-4700, Epicron HP-4770 (all manufactured by Dainippon Ink and Chemicals), and NC-7000 (manufactured by Nippon Kayaku Co., Ltd.). Can be mentioned.

  Examples of the aromatic polyglycidyl ether compound include hydroquinone diglycidyl ether (the following structural formula E101), catechol diglycidyl ether (the following structural formula E102), resorcinol diglycidyl ether (the following structural formula E103), and tris (4-glycidyloxyphenyl). ) Methane (following structural formula E105), 1031S, 1032H60 (all manufactured by Japan Epoxy Resin), TACTIX-742 (manufactured by Dow Chemical Company), Denacol EX-201 (manufactured by Nagase ChemteX Corporation), DPPN-503, DPPN- 502H, DPPN-501H, NC6000 (all manufactured by Nippon Kayaku Co., Ltd.), Techmore VG3101L (manufactured by Mitsui Chemicals), a compound represented by the following structural formula E106, and a compound represented by the following structural formula E107 It is.

  Examples of the dicyclopentadiene phenol type epoxy compound include TACTIX-556 (manufactured by Dow Chemical Co.) and Epicron HP-7200 (manufactured by Dainippon Ink & Chemicals, Inc.).

  Examples of the alicyclic diglycidyl ether compound include cyclohexane dimethanol diglycidyl ether compound and licarresin DME-100 (manufactured by Shin Nippon Rika).

Examples of the aliphatic polyglycidyl ether compound include ethylene glycol diglycidyl ether (the following structural formula E108), diethylene glycol diglycidyl ether (the following structural formula E109), polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether (the following structural formula E110). ), Tripropylene glycol diglycidyl ether (the following structural formula E111), polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether (the following structural formula E112), 1,4-butanediol diglycidyl ether (the following structural formula E113), 1,6-hexanediol diglycidyl ether (the following structural formula E114), dibromoneopentyl glycol diglycidyl ether (the following structural formula E 15), Denacol EX-810, Denacol EX-851, Denacol EX-8301, Denacol EX-911, Denacol EX-920,
Denacol EX-931, Denacol EX-211, Denacol EX-212, Denacol EX-313 (all manufactured by Nagase ChemteX), DD-503 (Asahi Denka), Rica Resin W-100 (New Nippon Rika), 1 , 3,5,6-tetraglycidyl-2,4-hexanediol (the following structural formula E116), glycerin polyglycidyl ether, sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, Denacol EX-313 , Denacol EX-611, Denacol EX-321, and Denacol EX-411 (all manufactured by Nagase ChemteX Corporation).

  Examples of the polysulfide-type diglycidyl ether compound include FLDP-50 and FLDP-60 (both manufactured by Toraythiol Coal).

  Examples of the biphenol type epoxy compound include YX-4000, YL-6121H (all manufactured by Japan Epoxy Resin), NC-3000P, and NC-3000S (all manufactured by Nippon Kayaku Co., Ltd.).

Examples of the diglycidyl ester compound include diglycidyl terephthalate (the following structural formula 117), diglycidyl phthalate (the following structural formula E118), bis (2-methyloxiranylmethyl) phthalate (the following structural formula E119), and the following structural formula. Examples thereof include a compound represented by E121, a compound represented by the following structural formula E122, and a compound represented by the following structural formula E123.

  Examples of the glycidyl ester epoxy compound include 871, 872 (all manufactured by Japan Epoxy Resin), Epicron 200, Epicron 400 (all manufactured by Dainippon Ink & Chemicals, Inc.), Denacol EX-711, and Denacol EX-721. (Both manufactured by Nagase ChemteX Corporation).

Examples of the polyglycidylamine compound include N, N-diglycidylaniline (the following structural formula E124), N, N-diglycidyl-o-toluidine (the following structural formula E125), N, N-diglycidyl-m-toluidine (the following structural formula). Structural formula E126), N, N-diglycidyl-2,4,6-tribromoaniline (the following structural formula E127), 3- (N, N-diglycidyl) aminopropyltrimethoxysilane (the following structural formula E128), N, N, O-triglycidyl-p-aminophenol (the following structural formula E129), N, N, O-triglycidyl-m-aminophenol (the following structural formula E130), N, N, N ′, N′-tetraglycidyl -M-xylylenediamine (TETRAD-X (Mitsubishi Gas Chemical), structural formula E132 below), 1,3-bis (N, N-digly Dilaminomethyl) cyclohexane (TETRAD-C (Mitsubishi Gas Chemical), structural formula E133), 1,4-bis (N, N-diglycidylaminomethyl) cyclohexane (structural formula E134), 1,3-bis ( N, N-diglycidylamino) cyclohexane (the following structural formula E135), 1,4-bis (N, N-diglycidylamino) cyclohexane (the following structural formula E136), 1,3-bis (N, N-diglycidyl) Amino) benzene (the following structural formula E137), 1,4-bis (N, N-diglycidylamino) benzene (the following structural formula E138), 2,6-bis (N, N-diglycidylaminomethyl) bicyclo [2 2.1] heptane (the following structural formula E139), N, N, N ′, N′-tetraglycidyl-4,4′-diaminodicyclohexylmethane (the following Structural formula E140), 2,2′-dimethyl- (N, N, N ′, N′-tetraglycidyl) -4,4′-diaminobiphenyl (the following structural formula E141), N, N, N ′, N ′ -Tetraglycidyl-4,4'-diaminodiphenyl ether (the following structural formula E142), 1,3,5-tris (4- (N, N-diglycidyl) aminophenoxy) benzene (the following structural formula E143), 2,4, 4′-tris (N, N-diglycidylamino) diphenyl ether (the following structural formula E144), tris (4- (N, N-diglycidyl) aminophenyl) methane (the following structural formula E145), 3,4,3 ′, 4′-tetrakis (N, N-diglycidylamino) biphenyl (the following structural formula E146), 3,4,3 ′, 4′-tetrakis (N, N-diglycidylamino) diphenyl ether (the following structure) Equation E147), a compound represented by the following structural formula E148, and compounds represented by the following structural formula E149.

  Examples of the homopolymer of the monomer having oxiranyl include polyglycidyl methacrylate. Examples of the oxiranyl-containing monomer copolymer include N-phenylmaleimide-glycidyl methacrylate copolymer, N-cyclohexylmaleimide-glycidyl methacrylate copolymer, benzyl methacrylate-glycidyl methacrylate copolymer, butyl methacrylate-glycidyl methacrylate copolymer. Examples include polymers, 2-hydroxyethyl methacrylate-glycidyl methacrylate copolymers, (3-ethyl-3-oxetanyl) methyl methacrylate-glycidyl methacrylate copolymers, and styrene-glycidyl methacrylate copolymers.

  Examples of the monomer having oxiranyl include glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, and methyl glycidyl (meth) acrylate.

Examples of the monomer other than the oxiranyl-containing monomer in the oxiranyl-containing monomer copolymer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl ( (Meth) acrylate, iso-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Examples include styrene, methylstyrene, chloromethylstyrene, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, N-cyclohexylmaleimide, and N-phenylmaleimide.

  Examples of the glycidyl isocyanurate include 1,3,5-triglycidyl-1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione (the following structural formula E150), 1,3. -Diglycidyl-5-allyl-1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione (the following structural formula E151), and glycidyl isocyanurate type epoxy resin.

  Examples of the chain aliphatic epoxy compound include epoxidized polybutadiene and epolide PB3600 (manufactured by Daicel Chemical Industries, Ltd.).

  Examples of the cycloaliphatic epoxy compound include 2-methyl-3,4-epoxycyclohexylmethyl-2′-methyl-3 ′, 4′-epoxycyclohexylcarboxylate (the following structural formula E153), 2,3-epoxy. Cyclopentane-2 ′, 3′-epoxycyclopentane ether (the following structural formula E154), ε-caprolactone-modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 1, 2: 8,9 -Diepoxy limonene (Celoxide 3000 (manufactured by Daicel Chemical Industries, Ltd.), the following structural formula E155), a compound represented by the following structural formula E156, CY-175, CY-177, CY-179 (all CIBA-GEIGY EHPD-3150 (manufactured by Daicel Chemical Industries, Ltd.), and Jo aliphatic epoxy resins.

For example, the liquid crystal aligning agent of the present invention may further contain a coupling agent such as a silane coupling agent, a titanium-based coupling agent, and an aminosilicon compound from the viewpoint of improving the adhesion to the substrate. Good. The coupling agent may be a single compound or two or more compounds.

  Examples of the aminosilicon compound include paraaminophenyltrimethoxysilane, paraaminophenyltriethoxysilane, metaaminophenyltrimethoxysilane, metaaminophenyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, and the like.

  The content of the coupling agent is preferably 0.01 to 3% by weight in the liquid crystal aligning agent.

  In addition, for example, the liquid crystal aligning agent of the present invention further includes polymer components such as polyester, acrylic acid polymer, and acrylate polymer within a range that does not impair the characteristics of the present invention (preferably within 20% by weight of the polyamic acid or its derivative). You may contain.

  Further, for example, the liquid crystal aligning agent of the present invention is a polyamide which is a reaction product of dicarboxylic acid or its derivative and diamine, or a polyamide which is a reaction product of tetracarboxylic dianhydride, dicarboxylic acid or its derivative and diamine. You may further contain other polymer components, such as an imide, in the range which does not impair the objective of this invention.

  Further, for example, the liquid crystal aligning agent of the present invention may further contain a surfactant according to the purpose from the viewpoint of improving the coating property of the liquid crystal aligning agent, and the antistatic property of the liquid crystal aligning agent is improved. From the viewpoint of making it, an antistatic agent may be further contained.

  For example, the liquid crystal aligning agent of this invention may further contain the solvent from a viewpoint of the applicability | paintability of a liquid crystal aligning agent, and the adjustment of the density | concentration of the said polyamic acid or its derivative (s). The solvent can be applied without any particular limitation as long as it has a capability of dissolving the polymer component. The said solvent contains the solvent normally used in the manufacturing process and use surface of polymer components, such as a polyamic acid and a soluble polyimide, and can be suitably selected according to the intended purpose. The solvent may be one kind or a mixed solvent of two or more kinds.

  Examples of the solvent include a parent solvent for the polyamic acid or a derivative thereof and other solvents for the purpose of improving coatability.

  Examples of the aprotic polar organic solvent that is a parent solvent for the polyamic acid or derivative thereof include N-methyl-2-pyrrolidone, dimethylimidazolidinone, N-methylcaprolactam, N-methylpropionamide, N, N-dimethyl. Examples include lactones such as acetamide, dimethyl sulfoxide, N, N-dimethylformamide, N, N-diethylformamide, diethylacetamide, and γ-butyrolactone.

  Examples of other solvents for the purpose of improving coating properties include alkyl lactate, 3-methyl-3-methoxybutanol, tetralin, isophorone, ethylene glycol monoalkyl ethers such as ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, etc. Diethylene glycol monoalkyl ether, ethylene glycol monoalkyl or phenyl acetate, triethylene glycol monoalkyl ether, propylene glycol monoalkyl ether such as propylene glycol monobutyl ether, dialkyl malonate such as diethyl malonate, dipropylene glycol monomethyl ether, etc. Examples include propylene glycol monoalkyl ether and ester compounds such as these acetates.

  Among these, the solvent particularly includes N-methyl-2-pyrrolidone, dimethylimidazolidinone, γ-butyrolactone, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and the like. It can be preferably used.

  In the present invention, the concentration of the polymer component containing the polyamic acid or derivative thereof in the liquid crystal aligning agent is not particularly limited, but is preferably 0.1 to 40% by weight. When the liquid crystal aligning agent is applied to the substrate, it may be necessary to dilute the polymer component contained in advance with a solvent in order to adjust the film thickness. A concentration of the polymer component of 40% by weight or less is suitable for easily mixing a solvent with the liquid crystal aligning agent when the liquid crystal aligning agent needs to be diluted for film thickness adjustment. The viscosity is preferable from the viewpoint of adjusting the viscosity of the liquid crystal aligning agent.

  Further, the concentration of the polymer component in the liquid crystal aligning agent may be adjusted by a coating method of the liquid crystal aligning agent. When the application method of the liquid crystal aligning agent is a spinner method or a printing method, the concentration of the polymer component is usually 10% by weight or less in order to maintain a good film thickness. Other coating methods such as a dipping method or an ink jet method may further reduce the concentration. On the other hand, when the concentration of the polymer component is 0.1% by weight or more, the thickness of the obtained liquid crystal alignment film tends to be optimal. Therefore, the concentration of the polymer component is 0.1% by weight or more, preferably 0.5 to 10% by weight in the usual spinner method or printing method. However, depending on the application method of the liquid crystal aligning agent, it may be used at a dilute concentration.

  In addition, when using for preparation of a liquid crystal aligning film, the viscosity of the liquid crystal aligning agent of this invention can be determined according to the means and method of forming this liquid crystal aligning agent film. For example, when a film of a liquid crystal aligning agent is formed using a printing machine, it is preferably 5 mPa · s or more from the viewpoint of obtaining a sufficient film thickness, and 100 mPa · s or less from the viewpoint of suppressing printing unevenness. It is preferably 10 to 80 mPa · s. When a liquid crystal aligning agent is applied by spin coating to form a liquid crystal aligning agent film, it is preferably 5 to 200 mPa · s, more preferably 10 to 100 mPa · s from the same viewpoint. The viscosity of the liquid crystal aligning agent can be reduced by curing with dilution or stirring with a solvent.

  The liquid crystal aligning agent of the present invention may be in the form of a so-called polymer blend. The liquid crystal aligning agent of such a form includes a reaction product of polyamic acid or its derivative A, which is a reaction product of tetracarboxylic dianhydride A and diamine A, and tetracarboxylic dianhydride B and diamine B. In the liquid crystal aligning agent containing the polyamic acid or its derivative B, which is a product, the diamine A contains the diamine represented by the general formula (1), and the diamine B does not contain the diamine represented by the general formula (1). A liquid crystal aligning agent is mentioned.

  The polyamic acid or derivative A thereof is the same as the polyamic acid or derivative thereof in the present invention described above. The polyamic acid or its derivative B is the above-mentioned polyamic acid or its derivative in the present invention except that the diamine does not contain the diamine represented by the general formula (1), that is, the diamine is the other diamine. The same.

  As the tetracarboxylic dianhydrides A and B, the above-described tetracarboxylic acids can be used. The diamine A only needs to contain the diamine represented by the general formula (1), and may further contain other diamines described above. As the diamine B, other diamines other than the diamine represented by the general formula (1) can be used.

The content of the polyamic acid or its derivative B in the liquid crystal aligning agent of the present invention is not particularly limited as long as the effect of the present invention is manifested, but is 1 to the total amount of the polymer in the liquid crystal aligning agent. The amount is preferably 50% by weight from the viewpoint of achieving both the expression of the effect of the present invention and the adjustment of the orientation, and more preferably 2 to 30% by weight.

  The liquid crystal aligning film of this invention is obtained from the liquid crystal aligning agent of this invention mentioned above. The liquid crystal alignment film of the present invention can be obtained by an ordinary method for producing a liquid crystal alignment film from a liquid crystal aligning agent. For example, the liquid crystal alignment film of the present invention includes a step of forming a coating film of the liquid crystal aligning agent of the present invention. The step of heating and baking this can be obtained. About the liquid crystal aligning film of this invention, you may rub the film | membrane obtained at the said baking process as needed.

  The said coating film can be formed by apply | coating the liquid crystal aligning agent of this invention to the board | substrate in a liquid crystal display element similarly to preparation of a normal liquid crystal aligning film. Examples of the substrate include a glass substrate on which an electrode such as an ITO (Indium Tin Oxide) electrode, a color filter, or the like may be provided.

  As a method for applying a liquid crystal aligning agent to a substrate, a spinner method, a printing method, a dipping method, a dropping method, an ink jet method and the like are generally known. These methods are similarly applicable in the present invention.

  The coating film can be baked under conditions necessary for the polyamic acid or its derivative to exhibit a dehydration / ring-closing reaction. For the baking of the coating film, a method of heat treatment in an oven or an infrared furnace, a method of heat treatment on a hot plate, and the like are generally known. These methods are equally applicable in the present invention. In general, it is preferably performed at a temperature of about 150 to 300 ° C. for 1 minute to 3 hours.

  The rubbing treatment can be performed in the same manner as the rubbing treatment for the alignment treatment of a normal liquid crystal alignment film, and may be any conditions as long as sufficient retardation is obtained in the liquid crystal alignment film of the present invention. Particularly preferable conditions are a push-in amount of 0.2 to 0.8 mm, a stage moving speed of 5 to 250 mm / sec, and a roller rotation speed of 500 to 2,000 rpm. As an alignment treatment method for the liquid crystal alignment film, in addition to the rubbing method, an optical alignment method, a transfer method, and the like are generally known. As long as the effects of the present invention can be obtained, these other alignment treatment methods may be used in combination in the rubbing treatment.

  The liquid crystal alignment film of the present invention can be suitably obtained by a method that further includes steps other than the steps described above. Examples of such other steps include a step of drying the coating film and a step of washing the film before and after the rubbing treatment with a washing liquid.

  As the drying step, a method of heat treatment in an oven or an infrared furnace, a method of heat treatment on a hot plate, and the like are generally known as in the baking step. These methods are also applicable to the drying step. The drying step is preferably performed at a temperature within a range where the solvent can be evaporated, and more preferably at a temperature relatively lower than the temperature in the baking step.

  Examples of the cleaning method using the cleaning liquid for the liquid crystal alignment film before and after the alignment treatment include brushing, jet spray, steam cleaning, and ultrasonic cleaning. These methods may be performed alone or in combination. The cleaning liquid is pure water or various alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol, aromatic hydrocarbons such as benzene, toluene and xylene, halogen solvents such as methylene chloride, and ketones such as acetone and methyl ethyl ketone. Although it can be used, it is not limited to these. Of course, these cleaning liquids are sufficiently purified and have few impurities. Such a cleaning method can also be applied to the cleaning step in the formation of the liquid crystal alignment film of the present invention.

  Although the film thickness of the liquid crystal aligning film of this invention is not specifically limited, It is preferable that it is 10-300 nm, and it is more preferable that it is 30-150 nm. The film thickness of the liquid crystal alignment film of the present invention can be measured by a known film thickness measuring device such as a step meter or an ellipsometer.

  The liquid crystal display element of the present invention includes a pair of substrates, a liquid crystal layer containing liquid crystal molecules, formed between the pair of substrates, an electrode for applying a voltage to the liquid crystal layer, and the liquid crystal molecules in a predetermined direction. And a liquid crystal alignment film to be aligned. The liquid crystal alignment film of the present invention is used for the liquid crystal alignment film.

  The glass substrate described above with the liquid crystal alignment film of the present invention can be used as the substrate, and the ITO electrode formed on the glass substrate as described above with the liquid crystal alignment film of the present invention can be used as the electrode. Can be used.

  The liquid crystal layer is formed of a liquid crystal composition that is sealed in a gap between a pair of substrates facing each other so that a surface of one of the pair of substrates on which a liquid crystal alignment film is formed faces the other substrate. .

  The liquid crystal composition is not particularly limited, and various liquid crystal compositions having a positive or negative dielectric anisotropy can be used. Preferred liquid crystal compositions having a positive dielectric anisotropy include Japanese Patent No. 3086228, Japanese Patent No. 2635435, Japanese Patent Laid-Open No. 5-501735, Japanese Patent Laid-Open No. 8-157826, and Japanese Patent Laid-Open No. 8-231960. JP-A-9-241644 (EP88272A1 specification), JP-A-9-302346 (EP806466A1 specification), JP-A-8-199168 (EP722998A1 specification), JP-A-9-235552, JP Japanese Laid-Open Patent Publication Nos. 9-255958, 9-241463 (EP882711A1), 10-204016 (EP844229A1), 10-204436, 10-231482, and JP 2000-087040, JP 2001-488 The liquid crystal composition disclosed in 2 publications, and the like.

  Preferred liquid crystal compositions having a negative dielectric anisotropy include JP-A-57-114532, JP-A-2-4725, JP-A-4-222485, JP-A-8-40953, JP-A-8-104869, JP-A-10-168076, JP-A-10-168453, JP-A-10-236989, JP-A-10-236990, JP-A-10-236992, JP-A-10- No. 236993, JP-A-10-236994, JP-A-10-237000, JP-A-10-237004, JP-A-10-237024, JP-A-10-237035, JP-A-10-237075 Publication, Unexamined-Japanese-Patent No. 10-237076, Unexamined-Japanese-Patent No. 10-237448 (EP967261A1 specification), Japanese Laid-Open Patent Publication Nos. 10-287874, 10-287875, 10-291945, 11-029581, 11-080049, 2000-256307, 2001-2001. Examples thereof include liquid crystal compositions disclosed in Japanese Unexamined Patent Application Publication No.

  One or more optically active compounds may be added to the liquid crystal composition having a positive or negative dielectric anisotropy.

In the liquid crystal display element of the present invention, the liquid crystal alignment film of the present invention is formed on at least one of a pair of substrates, and the obtained pair of substrates are opposed to each other with a liquid crystal alignment film facing inward through a spacer. It is obtained by enclosing a liquid crystal composition in the formed gap to form a liquid crystal layer. The production of the liquid crystal display element of the present invention may include additional steps such as attaching a polarizing film to the substrate as necessary.

  The liquid crystal display element of the present invention can form liquid crystal display elements for various electric field systems. In such a liquid crystal display element for electric field mode, a liquid crystal display element for horizontal electric field mode in which the electrode applies a voltage to the liquid crystal layer in a horizontal direction with respect to the surface of the substrate, or a surface of the substrate. In addition, there is a vertical electric field type liquid crystal display element in which the electrode applies a voltage to the liquid crystal layer in the vertical direction.

  Since the liquid crystal display element for the horizontal electric field mode does not have to exhibit a relatively large pretilt angle, a liquid crystal alignment film using the liquid crystal alignment agent of the present invention obtained from a diamine not containing a diamine having a side chain is suitable. Used.

  Since the liquid crystal display element for the vertical electric field method requires a relatively large pretilt angle, it can be obtained from a diamine containing a diamine having a side chain in addition to the diamine represented by the general formula (1), or The liquid crystal aligning film by the liquid crystal aligning agent of this invention containing the diamine which has a side chain in the said diamine B is used suitably.

  As described above, the liquid crystal alignment film produced using the liquid crystal aligning agent of the present invention as a raw material can be applied to liquid crystal display elements of various display drive systems by appropriately selecting a polymer as the raw material.

  Examples Hereinafter, the liquid crystal aligning agent and the liquid crystal display element obtained by using the polymer of the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In the examples, GPC was used for measuring the molecular weight, polystyrene was used as the standard solution, and DMF was used as the eluent. In the following examples, the unit liter of volume is indicated by L. Therefore, mL means milliliter.

Below, the evaluation method of the liquid crystal display element used in the Example is described.
(1) Residual DC
After a 3 V DC voltage was superimposed on a 30 Hz, 3 V rectangular wave for 30 minutes, the flicker erasing voltage after 5 minutes was measured, and the absolute value of this value was defined as residual DC. It can be said that the smaller the residual DC, the less the seizure and the better.
(2) Voltage holding ratio (VHR)
The method described in “Mizushima et al., Proceedings of the 14th Liquid Crystal Symposium p78 (1988)” was used. In the measurement, a rectangular wave having a gate width of 69 μs, a frequency of 60 Hz, and a wave height of ± 5 V was applied to the cell. The measurement temperature was 60 ° C.
(3) Retardation (R) Measurement The retardation (R) of the alignment film was determined using a spectroscopic ellipsometer M-2000U (manufactured by JA Woollam Co. Inc.). The larger the value of R, the longer the alignment film is stretched in the rubbing direction and the higher the uniaxial orientation. As a result, it can be said that black display is good.
(4) Pretilt angle (Pt angle)
Measurement was performed at room temperature using a liquid crystal evaluation apparatus (OMS-CA3) manufactured by Chuo Seiki Co., Ltd.

  The names of tetracarboxylic dianhydrides, diamines and solvents used in the examples and comparative examples are indicated by abbreviations. This abbreviation may be used in the following description.

Tetracarboxylic dianhydride 1,2,3,4-cyclobutanetetracarboxylic dianhydride: CBDA
Pyromellitic dianhydride: PMDA
Diamine 4,4'-Diaminodiphenylmethane: DDM
1,3-bis (4- (4-aminobenzyl) phenyl) propane: BZ3
4,4′-diaminodiphenyl ether: APE
1,1-bis [4-[(4-aminophenyl) methyl] phenyl] -4-n-butylcyclohexane: PMBCh
N, N′-bis (4-aminophenyl) -N, N′-dimethylethylenediamine
: NN2DAMe
2,6-diaminopyridine: DAPY
4,4′-Diaminodiphenylamine: DADPA
Solvent component N-methyl-2-pyrrolidone: NMP
γ-butyrolactone: GBL
Butyl cellosolve: BC

Synthesis example 1
Preparation of Liquid Crystal Alignment Film Composition A1 (Varnish A1) 2.83 g of NN2DAMe and 53.4 mL of dehydrated NMP were placed in a 100 mL four-necked flask equipped with a thermometer, stirrer, raw material charging inlet and nitrogen gas inlet. The solution was stirred and dissolved under a dry nitrogen stream. While maintaining the temperature of the reaction system at 5 ° C., 1.03 g of CBDA and 1.14 g of PMDA were added and reacted for 30 hours, and then 27.7 mL of BC and 13.3 mL of GBL were added to increase the concentration of the polymer component. A varnish of 5% by weight polyamic acid was prepared. When the reaction temperature rose due to reaction heat during the reaction of the raw materials, the reaction was carried out with the reaction temperature kept at about 70 ° C. or lower.

  In the examples of the present invention, the reaction was carried out while checking the viscosity during the reaction, and when the viscosity of the varnish after addition of BC reached 30 to 35 mPa · s (using an E-type viscometer, 25 ° C.). The reaction was terminated with and stored at a low temperature. The resulting polyamic acid had a weight average molecular weight of 62,320. In addition, the weight average molecular weight was measured at a column temperature of 50 ° C. using a GPC measuring apparatus (software Empower) manufactured by Waters.

  The varnish obtained as described above is diluted with a mixed solvent of NMP / BC / GBL (= 60/25/15, weight ratio) to adjust the concentration of all polymer components to 3% by weight. Varnish A1.

Synthesis Examples 2-8
Preparation of various varnishes Varnish A2 to A8 were prepared by the same method as varnish A1 except that the raw materials in Table 1 were used in the molar ratios shown in Table 1 below. Table 1 shows the raw material types and molar ratios of varnishes A1 to A8, and the weight average molecular weight of the resulting polyamic acid.

Example 1
Preparation of Pretilt Angle, Voltage Retention Ratio and Residual DC Measurement Cell a A glass substrate with an ITO electrode was used as the substrate of the measurement cell a.

  Varnish A1 obtained in Synthesis Example 1 was applied onto the above glass substrate with an ITO electrode with a spinner. The coating conditions were 1,700 rpm and 15 seconds. After the coating, pre-baking was performed at 80 ° C. for about 3 minutes, and then heat treatment was performed at 230 ° C. for 20 minutes to form a liquid crystal alignment film having a thickness of about 70 nm. Using a rubbing treatment apparatus manufactured by Iinuma Gauge Co., Ltd., the resulting polyimide film was pushed into a rubbing cloth (hair length 1.8 mm: rayon) by 0.40 mm, the stage moving speed was 60 mm / sec, and a roller The substrate was rubbed at a rotation speed of 1,000 rpm to obtain a liquid crystal sandwich substrate.

  The obtained liquid crystal sandwiching substrate was subjected to ultrasonic cleaning in ultrapure water for 5 minutes and then dried in an oven at 120 ° C. for 30 minutes. A 7 μm gap agent was sprayed on one glass substrate with an ITO electrode, and the other glass substrate with an ITO electrode was sealed with an epoxy curing agent to produce an anti-parallel cell with a gap of 7 μm. A liquid crystal material was injected into the cell, and the injection port was sealed with a photocuring agent. Subsequently, a heat treatment was performed at 110 ° C. for 30 minutes to obtain a cell a for measuring a pretilt angle, a voltage holding ratio, and a residual DC. The composition of the liquid crystal composition A used as the liquid crystal material is shown below. The NI point of this composition was 100.0 ° C., and the birefringence was 0.093.

Measurement of pretilt angle, voltage holding ratio and residual DC Using the measurement cell a, the pretilt angle, voltage holding ratio and residual DC were measured by the method described above. The pretilt angle was 2.3 ° and the voltage holding ratio. Was 99.0%, and the residual DC was 2 mV.

Production of Retardation Measurement Substrate b A transparent glass substrate was used as the measurement substrate b.

  Varnish A1 obtained in Synthesis Example 1 was applied onto the transparent glass substrate with a spinner. The coating conditions were 1,700 rpm and 15 seconds. After the coating, pre-baking was performed at 80 ° C. for about 3 minutes, and then heat treatment was performed at 230 ° C. for 20 minutes to form a liquid crystal alignment film having a thickness of about 70 nm. Using a rubbing treatment apparatus manufactured by Iinuma Gauge Co., Ltd., the resulting polyimide film was pushed into a rubbing cloth (hair length 1.8 mm: rayon) by 0.40 mm, the stage moving speed was 60 mm / sec, and a roller A rubbing process was performed at a rotation speed of 1,000 rpm to obtain a measurement substrate b.

Retardation measurement The retardation was calculated | required with the spectroscopic ellipsometer using the obtained board | substrate b for a measurement. The obtained R was 0.65 nm.

Examples 2-7
Using the varnishes A2 to A7 obtained in Synthesis Examples 2 to 7, the measurement cell a and the measurement substrate b were produced in the same manner as in Example 1, and the pretilt angle, the voltage holding ratio (VHR), the residual DC, and the retardation were produced. (R) was measured in the same manner as in Example 1. The measurement results are shown in Table 2.

  In the test methods of the examples of the present invention, the voltage holding ratio is good if it is a value of 99.0% or more, good if the residual DC is a value of 10 mV or less, and the retardation is 0.2 nm or more. A value of is good. When the retardation value is 0.2 nm or less, the alignment force is weak, and light leakage may occur during flow alignment or when no voltage is applied. This is an important parameter especially for the horizontal electric field method. Regarding the pretilt angle, the desired value differs depending on each driving method, so it cannot be determined whether the obtained numerical value is good or bad. However, a small value is preferable (less than 3.0 °) in the lateral electric field method such as IPS. In the vertical electric field system represented by TN, a relatively large value (4.0 ° or more) is preferable.

Examples 8 and 9
Varnishes A1, A2 and A8 were prepared with the polymer compositions (weight ratios) shown in Table 3 below, and the pretilt angle, voltage holding ratio, residual DC and retardation were measured using the same as in Example 1. Went to. Table 3 shows the measurement results.

Example 10
20 g of varnish A1 obtained in Synthesis Example 1 (solid content concentration 5 wt%) and 0.1 g of epoxy compound 4,4′-methylenebis (N, N-diglycidylaniline) (manufactured by Sigma-Aldrich) (10% by weight based on the polymer of varnish A1) was mixed to prepare varnish B1, and using this, the pretilt angle, voltage holding ratio, residual DC, and retardation were measured in the same manner as in Example 1. It was.

Synthesis Examples 10-14
Preparation of various varnishes Varnishes C1 to C5 were prepared by the same method as varnish A1 except that the raw materials shown in Table 5 below were used in the molar ratios shown in Table 5 below. Table 5 shows the types of raw materials of varnishes C1 to C5, the molar ratio thereof, and the weight average molecular weight of the obtained polyamic acid.

Comparative Examples 1-5
Using the varnishes C1 to C5 obtained in Synthesis Examples 10 to 14 instead of the varnish A1, the measurement cell a and the measurement substrate b were prepared in the same manner as in Example 1, and the pretilt angle, voltage holding ratio, residual DC, The retardation was measured in the same manner as in Example 1. Table 6 shows the measurement results.

  As is clear from the results of Examples 1 to 10 and Comparative Examples 1 to 5, by using a polyamic acid containing a diamine containing a tertiary amine in the present invention, a reduction in residual DC and a large retardation are simultaneously satisfied. A liquid crystal display element that can be manufactured can be manufactured.

Claims (39)

In the liquid crystal aligning agent containing polyamic acid or a derivative thereof which is a reaction product of tetracarboxylic dianhydride and diamine,
The diamine is a liquid crystal aligning agent containing a diamine represented by the following general formula (1).

(In the general formula (1), R ¹ independently represents a monovalent organic group, R ² independently represents a monovalent group, and Z represents a divalent group containing an alkylene having 1 to 5 carbon atoms. Represents.) The liquid crystal aligning agent according to claim 1, wherein R ¹ is independently alkyl having 1 to 3 carbon atoms, and R ² is independently hydrogen, alkyl having 1 to 3 carbon atoms, fluorine, chlorine, or bromine.   The liquid crystal aligning agent according to claim 1 or 2, wherein the diamine represented by the general formula (1) has an amino at each para position relative to the NZN main chain in phenyl at both ends. The liquid crystal aligning agent according to claim 3, wherein the diamine represented by the general formula (1) is one or more selected from the group consisting of the following structural formulas 239 to 253 and 258 to 262.

5. The liquid crystal aligning agent according to claim 1, wherein the tetracarboxylic dianhydride is one or more selected from the following structural formulas 500, 505 to 508, 511, 515, and 517.

  The liquid crystal aligning agent according to claim 5, wherein the tetracarboxylic dianhydride is one or both of the structural formulas 500 and 511. The liquid crystal aligning agent according to any one of claims 1 to 6, wherein the diamine further includes a diamine represented by the following general formula (2).

(In the general formula (2), R ³ is substituted not including a good good diacetic above also represent a divalent organic group.) The liquid crystal aligning agent of Claim 7 in which the diamine represented by General formula (2) contains the diamine represented by the following general formula (3)-(5).

(In General Formula (3), Y represents a divalent group containing one or more alkylene having 1 to 5 carbon atoms, oxygen, and sulfur.)

(In General Formula (4), X ¹ independently represents methylene or oxygen, and X ² represents methyl or CF ₃ alkylene which may have CF ₃ as a substituent.)

(In General Formula (5), X ¹ independently represents alkylene having 1 to 6 carbon atoms or oxygen, X ³ represents a single bond or alkylene having 1 to 3 carbon atoms, and ring T represents 1,4-phenylene. Or R ⁴ is hydrogen or alkyl having 1 to 30 carbons (provided that any methylene in the alkyl having 2 to 30 carbons is independently oxygen, -CH ═CH— or —C≡C—, but in the alkyl, oxygen is not adjacent.) And h represents 0 or 1.) The liquid crystal aligning agent according to claim 8, wherein in the general formulas (3) to (5), the two amino positions are para to Y or X ¹ . The diamine represented by the general formula (3) is one or more selected from the group consisting of the following structural formulas 301 to 304, 306, 307, and 313,
The diamine represented by the general formula (4) is one or more selected from the group consisting of the following structural formulas 360, 364, 365, 367, and 372,
The liquid crystal aligning agent according to claim 9, wherein the diamine represented by the general formula (5) is one or more selected from the group consisting of the following structural formulas 381, 384, 390, and 398.

  The diamine has a content of diamine represented by the general formula (1) of 20 to 99 mol%, and a content of diamine represented by the general formula (2) of 1 to 80 mol%. The liquid crystal aligning agent as described in any one of 10-10. A polyamic acid or derivative A thereof, which is a reaction product of tetracarboxylic dianhydride A and diamine A, and a polyamic acid or derivative B thereof which is a reaction product of tetracarboxylic dianhydride B and diamine B. In the liquid crystal aligning agent to contain,
The diamine A includes a diamine represented by the following general formula (1),
The diamine B is a liquid crystal aligning agent not containing a diamine represented by the following general formula (1).

(In the general formula (1), R ¹ independently represents a monovalent organic group, R ² independently represents a monovalent group, and Z represents a divalent group containing an alkylene having 1 to 5 carbon atoms. Represents.) In the general formula (1), R ¹ is independently alkyl having 1 to 3 carbon atoms, and R ² is independently hydrogen, alkyl having 1 to 3 carbon atoms, fluorine, chlorine, or bromine. The liquid crystal aligning agent of description.   The diamine represented by General formula (1) is a liquid crystal aligning agent of Claim 12 or 13 which has an amino in each para position with respect to a NZN main chain in phenyl of both ends. The liquid crystal aligning agent according to claim 14, wherein the diamine represented by the general formula (1) is one or more selected from the group consisting of the following structural formulas 239 to 253 and 258 to 262.

The liquid crystal aligning agent as described in any one of Claims 12-15 in which the said diamine B contains the diamine represented by following General formula (2).

(In the general formula (2), R ³ is substituted not including a good good diacetic above also represent a divalent organic group.) The liquid crystal aligning agent according to claim 16, wherein the general formula (2) diamine includes a diamine represented by the following general formulas (3) to (5).

(In General Formula (3), Y represents a divalent group containing one or more alkylene having 1 to 5 carbon atoms, oxygen, and sulfur.)

(In General Formula (4), X ¹ independently represents methylene or oxygen, and X ² represents methyl or CF ₃ alkylene which may have CF ₃ as a substituent.)

(In General Formula (5), X ¹ independently represents alkylene having 1 to 6 carbon atoms or oxygen, X ³ represents a single bond or alkylene having 1 to 3 carbon atoms, and ring T represents 1,4-phenylene. Or R ⁴ is hydrogen or alkyl having 1 to 30 carbons (provided that any methylene in the alkyl having 2 to 30 carbons is independently oxygen, -CH ═CH— or —C≡C—, but in the alkyl, oxygen is not adjacent.) And h represents 0 or 1.) The liquid crystal aligning agent according to claim 17, wherein in the general formulas (3) to (5), the two amino positions are para to Y or X ¹ . The diamine represented by the general formula (3) is one or more selected from the group consisting of the following structural formulas 301 to 304, 306, 307, and 313,
The diamine represented by the general formula (4) is one or more selected from the group consisting of the following structural formulas 360, 364, 365, 367, and 372,
The liquid crystal aligning agent according to claim 18, wherein the diamine represented by the general formula (5) is one or more selected from the group consisting of the following structural formulas 381, 384, 390, and 398.

20. The tetracarboxylic dianhydride A and the tetracarboxylic dianhydride B are one or more selected from the following structural formulas 500, 505 to 508, 511, 515, and 517. The liquid crystal aligning agent of description.

  21. The liquid crystal aligning agent according to claim 20, wherein the tetracarboxylic dianhydride A and the tetracarboxylic dianhydride B are one or both of the structural formulas 500 and 511.   The liquid crystal aligning agent according to any one of claims 1 to 21, further comprising an epoxy compound. The liquid crystal aligning agent of Claim 22 whose said epoxy compound is one or more chosen from the group which consists of following structural formula (E1)-(E3), (E5) and the following general formula (E4).

(In General Formula (E4), n represents an integer of 0 to 10)   The liquid crystal aligning agent of Claim 22 or 23 in which the said epoxy compound is contained 0.1 to 40weight% with respect to the total amount of the said polyamic acid or its derivative (s).   The liquid crystal aligning film obtained from the liquid crystal aligning agent as described in any one of Claims 1-24.   A pair of substrates, a liquid crystal layer containing liquid crystal molecules and formed between the pair of substrates, an electrode for applying a voltage to the liquid crystal layer, and a liquid crystal alignment film for aligning the liquid crystal molecules in a predetermined direction 26. The liquid crystal display element according to claim 25, wherein the liquid crystal alignment film is a liquid crystal alignment film according to claim 25.   27. The liquid crystal display element according to claim 26, wherein the electrode is a liquid crystal display element for a horizontal electric field mode in which a voltage is applied to the liquid crystal layer in a horizontal direction with respect to the surface of the substrate.   27. The liquid crystal display element according to claim 26, wherein the electrode is a vertical electric field type liquid crystal display element that applies a voltage to the liquid crystal layer in a direction perpendicular to a surface of the substrate. In the polymer that is a reaction product of tetracarboxylic dianhydride and diamine,
The diamine is a polymer containing a diamine represented by the following general formula (1) and a diamine represented by the following general formula (2).

(In the general formula (1), R ¹ independently represents a monovalent organic group, R ² independently represents a monovalent group, and Z represents a divalent group containing an alkylene having 1 to 5 carbon atoms. Represents.)

(In the general formula (2), R ³ is substituted not including a good good diacetic above also represent a divalent organic group.) 30. In the general formula (1), R ¹ is independently alkyl having 1 to 3 carbons, and R ² is independently hydrogen, alkyl having 1 to 3 carbons, fluorine, chlorine, or bromine. The polymer described.   The polymer according to claim 29 or 30, wherein the diamine represented by the general formula (1) has an amino at each para position with respect to the NZN main chain in phenyl at both ends. 32. The polymer according to claim 31, wherein the diamine represented by the general formula (1) is one or more selected from the group consisting of the following structural formulas 239 to 253 and 258 to 262.

  The polymer according to claim 32, wherein the diamine represented by the general formula (1) is the structural formula 240. The polymer according to any one of claims 29 to 33, wherein the diamine represented by the general formula (2) includes a diamine represented by the following general formulas (3) to (5).

(In General Formula (3), Y represents a divalent group containing one or more alkylene having 1 to 5 carbon atoms, oxygen, and sulfur.)

(In General Formula (4), X ¹ independently represents methylene or oxygen, and X ² represents methyl or CF ₃ alkylene which may have CF ₃ as a substituent.)

(In General Formula (5), X ¹ independently represents alkylene having 1 to 6 carbon atoms or oxygen, X ³ represents a single bond or alkylene having 1 to 3 carbon atoms, and ring T represents 1,4-phenylene. Or R ⁴ is hydrogen or alkyl having 1 to 30 carbons (provided that any methylene in the alkyl having 2 to 30 carbons is independently oxygen, -CH ═CH— or —C≡C—, but in the alkyl, oxygen is not adjacent.) And h represents 0 or 1.) In the general formula (3) to (5), polymer of claim 34 positions of the two amino is para to Y or X ^1. The diamine represented by the general formula (3) is one or more selected from the group consisting of the following structural formulas 301 to 304, 306, 307, and 313,
The diamine represented by the general formula (4) is one or more selected from the group consisting of the following structural formulas 360, 364, 365, 367, and 372,
36. The polymer according to claim 35, wherein the diamine represented by the general formula (5) is one or more selected from the group consisting of the following structural formulas 381, 384, 390, and 398.

  The diamine represented by the general formula (3) is one or both of the structural formulas 301 and 306, the diamine represented by the general formula (4) is the structural formula 364, and is represented by the general formula (5). The polymer according to claim 36, wherein the diamine is structural formula 381. The polymer according to any one of claims 29 to 37, wherein the tetracarboxylic dianhydride is one or more selected from the following structural formulas 500, 505 to 508, 511, 515, and 517.

  39. The polymer of claim 38, wherein the tetracarboxylic dianhydride is one or both of structural formulas 500 and 511.