JP5387428B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent containing a polyamic acid obtained by reacting a diamine having an aromatic ring containing one or two nitrogen atoms with tetracarboxylic dianhydride or a derivative thereof. 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 laptop computers and desktop computers, video camera viewfinders, and projection displays. Recently, they are also widely used as display elements for televisions. Yes. 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 nematic liquid crystal is mainly used, and a TN (Twisted Nematic) type liquid crystal display element twisted by 90 degrees, and an STN (Super Twisted Nematic) type liquid crystal display element usually twisted by 180 degrees or more So-called TFT (Thin-film-transistor) type liquid crystal display elements using thin film transistors have been put into practical use.

  However, these liquid crystal display elements have a drawback 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 regard to this viewing angle problem, TN liquid crystal display elements using optical compensation films, MVA (Multi-domain Vertical Alignment) type liquid crystal display elements using vertical alignment and protrusion structure technology, or horizontal electric field system The IPS (In-Plane Switching) type liquid crystal display element and the like have 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.

  Residual DC is an important characteristic required for the liquid crystal alignment film in order to improve the display quality of the liquid crystal display element. When the residual DC is large, a so-called “afterimage” occurs in which an image to be erased remains even though the voltage is turned off after the voltage application.

  As an attempt to solve this afterimage, a liquid crystal aligning agent that provides a liquid crystal display element with less accumulated charge by using a sulfide bond-containing polyimide has been proposed (for example, see Patent Document 4).

  Furthermore, the combination of the ultraviolet light irradiation and the liquid crystal aligning agent containing the polyamic acid containing a pyrimidine skeleton is proposed (for example, refer patent document 5).

  These prior arts are further studied in terms of the electrical properties of the obtained liquid crystal alignment film and the materials for obtaining desired electrical properties as the liquid crystal alignment agent for forming the present liquid crystal alignment film, which is required to be further improved. There is room for.

Japanese Examined Patent Publication No. 63-21907 JP-A-6-160878 JP-A-9-15650 JP-A-5-263077 Japanese Patent Laid-Open No. 6-148637

  The present invention relates to a liquid crystal alignment film having a small residual DC, a polyamic acid and a polyimide polymer capable of forming the liquid crystal alignment film, an alignment film formed using the polymer, and the alignment film. An object is to provide a liquid crystal display element that does not occur.

  When the present inventors use, as a liquid crystal aligning agent, a composition containing a polyamic acid or a derivative thereof using a diamine having a heteroaromatic ring containing one or two nitrogen atoms in the molecule as a raw material, it is formed thereby. The present inventors have found that a liquid crystal display element having a liquid crystal alignment film can achieve low residual DC.

ここに、環Ｐはピリジン−２，５−ジイル、ピリダジン−３，６−ジイル、ピリミジン−２，５−ジイルまたはピラジン−２，５−ジイルであり；ｋは０または１である；但し、ｋ＝０のとき、環Ｐはピリジン−２，５−ジイルまたはピリミジン−２，５−ジイルであって、これらの環におけるアミノ基の結合位置は５位である。 The liquid crystal aligning agent of this invention is shown by the following [1] term.
[1] A polyamic acid obtained by reacting a diamine represented by the formula (P) or a mixture of the diamine represented by the formula (P) and another diamine with a tetracarboxylic dianhydride and a derivative thereof. Liquid crystal aligning agent containing at least one polymer selected from the group:

Wherein ring P is pyridine-2,5-diyl, pyridazine-3,6-diyl, pyrimidine-2,5-diyl or pyrazine-2,5-diyl; k is 0 or 1; When k = 0, ring P is pyridine-2,5-diyl or pyrimidine-2,5-diyl, and the binding position of the amino group in these rings is the 5-position.

  According to the present invention, it is possible to provide a liquid crystal display element having a low residual DC and applicable to various driving methods.

First, terms used in this specification will be described.
The diamine represented by the formula (P) may be abbreviated as diamine (P). Similarly, diamines represented by other formulas may be abbreviated. The tetracarboxylic dianhydride represented by Formula (1) may be abbreviated as an acid anhydride (1). Similarly, tetracarboxylic dianhydrides represented by other formulas may be abbreviated in the same manner. “(Meth) acryloyloxy” is a generic term for acryloyloxy and methacryloyloxy, “(meth) acrylate” is a generic term for acrylates and methacrylates, and “(meth) acrylic acid” is a term for acrylic acid and methacrylic acid. It is a generic name.

The term “arbitrary” used in describing a chemical structural formula means that not only the position but also the number is arbitrary. And, for example, the expression “any A may be replaced by B, C or D” means that at least one A may be replaced by B and at least one A may be replaced by C , Meaning that at least one A may be replaced by D, and more than one A may be replaced by at least two of BD. However, when arbitrary —CH ₂ — may be replaced with another group, it does not include the replacement of a plurality of consecutive —CH ₂ — with the same group. Ph means phenylene and Me means methyl.

  A substituent that is not clearly bonded to any one of the carbons constituting the ring means that the bonding position is free as long as there is no chemical problem. In the chemical structural formula, a group in which a letter (for example, P) is surrounded by a hexagon means a group having a ring structure (ring P). When the same symbol is used in more than one formula, it means that the ring, linking group or terminal group represented by the symbol has the same defined range, but the same group within the defined range at the same time in all formulas Doesn't mean it must be. The same group may be used in a plurality of formulas, or different groups may be used for each formula.

The present invention is composed of the above item [1] and the following items [2] to [21].
[2] The liquid crystal aligning agent according to the item [1], wherein the diamine represented by the formula (P) is at least one of the diamines represented by the formulas (P-1) to (P-10).

[3] The liquid crystal aligning agent according to the item [2], wherein the diamine represented by the formula (P) is at least one of the diamines represented by the formula (P-5) and the formula (P-8).

式（VIII）において、Ａ^３は単結合、−Ｏ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＣＨ_２Ｏ−、−ＣＦ_２Ｏ−、または炭素数１〜６のアルキレンであって、このアルキレンにおける任意の−ＣＨ_２−は−Ｏ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよく；Ｒ^１はステロイド骨格を有する基、炭素数３〜３０のアルキル、置換基として炭素数１〜３０のアルキルもしくは炭素数１〜３０のアルコキシを有するフェニル、または式（IX）で表される基であって、この炭素数３〜３０のアルキルにおける任意の−ＣＨ_２−は−Ｏ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよい：

式（IX）において、Ａ^４およびＡ^５は独立して単結合、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、炭素数１〜４のアルキレン、炭素数１〜３のオキシアルキレン、または炭素数１〜３のアルキレンオキシであり；環Ｂおよび環Ｃは独立して１，４−フェニレンまたは１，４−シクロヘキシレンであり；Ｒ^２およびＲ^３は独立してフッ素またはメチルであって、ｆおよびｇは独立して０、１または２であり；ｃ、ｄおよびｅは独立して０〜２の整数であって、これらの合計は１以上であり；ｃが２であるとき、２つの環Ｂは同じであっても異なってもよく、２つのＡ^４も同じ結合基であっても異なる結合基であってもよく；ｄが２であるとき、２つのＡ^５は同じ結合基であっても異なる結合基であってもよく；ｅが２であるとき、２つの環Ｃは同じであっても異なってもよく；Ｒ^４は炭素数１〜３０のアルキル、炭素数１〜３０のアルコキシまたは炭素数２〜３０のアルコキシアルキルであり、これらのアルキル、アルコキシおよびアルコキシアルキルにおいて、任意の水素はフッ素で置き換えられてもよい：

式（Ｘ）および式（XI）において、Ｒ^５は独立して水素またはメチルであり、Ｒ^６は水素、炭素数１〜２０のアルキルまたは炭素数２〜２０のアルケニルであり、Ｒ^７およびＲ^８は独立して炭素数１〜２０のアルキルまたはフェニルであり、Ａ^６は独立して単結合、−ＣＯ−または−ＣＨ_２−である：

式（XII）および式（XIII）において、Ｒ^９はメチルまたは炭素数２〜３０のアルキルであって、このアルキルの任意の−ＣＨ_２−は、−Ｏ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよく；Ｒ^１０は炭素数６〜２２のアルキルであり；Ｒ^１１は炭素数１〜２２のアルキルであり；Ａ^７は独立して−Ｏ−または炭素数１〜６のアルキレンであり；Ａ^８は単結合または炭素数１〜３のアルキレンであり；環Ｔは１，４−フェニレンまたは１，４−シクロヘキシレンであり；ｈは０または１である。 [4] The other diamine is at least one diamine selected from the group of diamines having a side chain group represented by formula (VIII) and formula (X) to formula (XIII), [1] to [3 ] The liquid crystal aligning agent in any one of these:

In formula (VIII), ^{A 3} is a single bond, -O -, - CO -, - COO -, - OCO -, - CONH -, - CH 2 O -, - CF 2 O-, or 6 carbon atoms Wherein any —CH ₂ — in the alkylene may be replaced by —O—, —CH═CH—, or —C≡C—; R ¹ is a group having a steroid skeleton, 3 carbon atoms An alkyl having 1 to 30 carbon atoms, phenyl having 1 to 30 carbon atoms or phenyl having 1 to 30 carbon atoms as a substituent, or a group represented by formula (IX), wherein the alkyl having 3 to 30 carbon atoms is Any —CH ₂ — may be replaced by —O—, —CH═CH— or —C≡C—:

In the formula (IX), A ⁴ and A ⁵ are independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or ring B and ring C are each independently 1,4-phenylene or 1,4-cyclohexylene; R ² and R ³ are each independently fluorine or methyl; And f and g are independently 0, 1 or 2; c, d and e are independently integers of 0 to 2 and their sum is 1 or more; c is 2 Sometimes the two rings B may be the same or different and the two A ⁴ may be the same or different linking groups; when d is 2, the two A ⁵ are They may be the same or different linking groups; when e is 2, One of the ring C may be the same or different; R ⁴ is an alkoxyalkyl of the alkoxy or C2-30 1-30 alkyl, carbon atoms having 1 to 30 carbon atoms, these alkyl, alkoxy and In alkoxyalkyl, any hydrogen may be replaced with fluorine:

In Formula (X) and Formula (XI), R ⁵ is independently hydrogen or methyl, R ⁶ is hydrogen, alkyl having 1 to 20 carbons or alkenyl having 2 to 20 carbons, R ⁷ and R ⁸ is independently alkyl having 1 to 20 carbons or phenyl, and A ⁶ is independently a single bond, —CO— or —CH ₂ —:

In Formula (XII) and Formula (XIII), R ⁹ is methyl or alkyl having 2 to 30 carbons, and any —CH ₂ — in the alkyl is —O—, —CH═CH— or —C R ¹⁰ is alkyl having 6 to 22 carbon atoms; R ¹¹ is alkyl having 1 to 22 carbon atoms; A ⁷ is independently —O— or 1 to carbon atoms. 6 is alkylene; A ⁸ is a single bond or alkylene having 1 to 3 carbon atoms; ring T is 1,4-phenylene or 1,4-cyclohexylene; h is 0 or 1.

これらの式において、Ｒ^２３、Ｒ^２９およびＲ^３０は独立して炭素数１〜３０のアルキル、または炭素数１〜３０のアルコキシである。 [5] Other diamines are represented by formula (VIII-2), formula (VIII-4) to formula (VIII-6), formula (XII-2), formula (XII-4) and formula (XII-6). The liquid crystal aligning agent according to item [4], which is at least one selected from diamines to be prepared:

In these formulas, R ²³ , R ²⁹ and R ³⁰ are independently alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons.

これらの式において、Ｘは炭素数２〜１２の直鎖アルキレンであり；Ｙは独立して単結合、−Ｏ−、−ＣＯ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯＮＨ−、−ＮＨＣＯ−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｏ−（ＣＨ_２）_ｔ−Ｏ−、−Ｓ−、−Ｓ−Ｓ−、−ＳＯ_２−、−Ｓ−（ＣＨ_２）_ｔ−Ｓ−または炭素数１〜１２の直鎖アルキレンであって、ｔは１〜１２の整数であり；Ｚ^１およびＺ^２は水素であるが、Ｙが−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＨ_２−、−Ｃ（ＣＨ_３）_２−または−Ｃ（ＣＦ_３）_２−であるときには互いに結合して単結合を形成してもよく；環Ｄはフェニレンまたは１，４−ジアザシクロヘキシレンであり；Ｒ^３３およびＲ^３４は独立して炭素数１〜３のアルキルまたはフェニルであり；Ａ^３は独立して炭素数１〜６のアルキレン、フェニレンまたはアルキル置換されたフェニレンであり；ｍは１〜１０の整数であり；シクロヘキサン環またはベンゼン環の任意の水素は、フッ素、メチル、トリフルオロメチル、−ＯＨ、−ＣＯＯＨ、−ＳＯ_３Ｈ、−ＰＯ_３Ｈ_２、ベンジルまたはヒドロキシベンジルで置き換えられてもよい。 [6] At least one other diamine selected from the group of diamines having a side chain group according to item [4], and side chains represented by formulas (I) to (VII) and (XV) The liquid crystal aligning agent according to any one of [1] to [3], which is a mixture with at least one selected from the group of diamines having no group:

In these formulas, X is a linear alkylene having 2 to 12 carbon atoms; Y is independently a single bond, —O—, —CO—, —NH—, —N (CH ₃ ) —, —CONH—. , —NHCO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —O— (CH ₂ ) _t —O—, —S—, —S—S—, —SO ₂ —, —S— (CH ₂ ) _t —S— or a linear alkylene having 1 to 12 carbon atoms, t is an integer of 1 to 12; Z ¹ and Z ² are hydrogen, but Y is —NH When-, -N (CH ₃ )-, -CH _2- , -C (CH ₃ ) ₂ -or -C (CF ₃ ) _2- , they may combine with each other to form a single bond; is phenylene or ^{1,4-diaza-cyclohexylene;} alkyl or phenyl ^{R 33} and ^{R 34} having 1 to 3 carbon atoms independently There; A ³ is independently an alkylene having 1 to 6 carbon atoms, be phenylene or alkyl-substituted phenylene; m is an integer from 1 to 10; cyclohexane ring or arbitrary hydrogen of benzene ring, fluorine, methyl , Trifluoromethyl, —OH, —COOH, —SO ₃ H, —PO ₃ H ₂ , benzyl or hydroxybenzyl.

これらの式において、Ｒ^２３、Ｒ^２９およびＲ^３０は独立して炭素数１〜３０のアルキル、または炭素数１〜３０のアルコキシである。

[7] Other diamines are represented by formula (VIII-2), formula (VIII-4) to formula (VIII-6), formula (XII-2), formula (XII-4) and formula (XII-6). At least one selected from diamines having a side chain group, formula (IV-1), formula (IV-2), formula (IV-15) to formula (IV-17), formula (V-1) To Formula (V-12), Formula (V-33), Formula (V-35) to Formula (V-37), Formula (VI-7), Formula (VII-2), and Formula (XV-1) The liquid crystal aligning agent as described in the item [6], which is a mixture with at least one selected from diamines having no side chain group.

In these formulas, R ²³ , R ²⁹ and R ³⁰ are independently alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons.

[8] The side chain group according to [4], wherein the polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to item [2]. A polyamic acid obtained by reacting a mixture with at least one selected from the group of diamines having a tetracarboxylic dianhydride or a derivative thereof, and the group of diamines having no side chain group according to item [6] The liquid crystal aligning agent as described in the item [1], which is a mixture with a polyamic acid obtained by reacting at least one selected from tetracarboxylic dianhydride or a derivative thereof.

[9] The side chain group according to [4], wherein the polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to item [2]. A polyamic acid obtained by reacting a mixture with at least one selected from the group of diamines having a tetracarboxylic dianhydride or a derivative thereof, and the group of diamines having no side chain group according to item [6] A polyamic acid obtained by reacting a mixture of at least one selected from the group consisting of at least one selected from the group of diamines represented by formulas (P-1) to (P-10) with tetracarboxylic dianhydride Alternatively, the liquid crystal aligning agent according to the item [1], which is a mixture with a derivative thereof.

[10] The side chain group according to [4], wherein the polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to item [2]. A mixture comprising at least one selected from the group of diamines having a diamine and at least one selected from the group of diamines having no side chain group described in item [6] is reacted with tetracarboxylic dianhydride. In the item [1], the polyamic acid or derivative thereof obtained is a mixture of the polyamic acid or derivative thereof obtained by reacting at least one diamine having no side chain group with tetracarboxylic dianhydride. The liquid crystal aligning agent of description.

[11] The side chain group according to [4], wherein the polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to item [2]. A mixture comprising at least one selected from the group of diamines having a diamine and at least one selected from the group of diamines having no side chain group described in item [6] is reacted with tetracarboxylic dianhydride. At least one selected from the group of diamines having no side chain group and at least one selected from the group of diamines represented by formulas (P-1) to (P-10) The liquid crystal aligning agent as described in the item [1], which is a mixture with a polyamic acid or a derivative thereof obtained by reacting a mixture with one with a tetracarboxylic dianhydride.

[12] The side chain group according to [6], wherein the polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to item [2]. A polyamic acid obtained by reacting a mixture of at least one selected from the group of diamines having no carboxylic acid with tetracarboxylic dianhydride or a derivative thereof, and the group of diamines having a side chain group according to item [4] The liquid crystal aligning agent as described in the item [1], which is a mixture with a polyamic acid obtained by reacting at least one selected from tetracarboxylic dianhydride or a derivative thereof.

[13] At least one polymer selected from the group of diamines represented by formula (P-1) to formula (P-10) according to item [2] and the side chain group according to item [6] A polyamic acid obtained by reacting a mixture of at least one selected from the group of diamines having no carboxylic acid with tetracarboxylic dianhydride or a derivative thereof, and the group of diamines having a side chain group according to item [4] A mixture of at least one selected from the group consisting of at least one selected from the group of diamines having no side chain group and a polyamic acid obtained by reacting with a tetracarboxylic dianhydride or a derivative thereof. The liquid crystal aligning agent as described in the item [1].

[14] The tetracarboxylic dianhydride is composed of at least one aromatic tetracarboxylic dianhydride or at least one aromatic tetracarboxylic dianhydride and at least one non-aromatic tetracarboxylic dianhydride. The liquid crystal aligning agent according to any one of [1] to [13], which is a mixture.

[15] Aromatics wherein tetracarboxylic dianhydride is represented by formula (H-1), formula (H-5), formula (H-8) to formula (H-10) and formula (H-22) The liquid crystal aligning agent according to any one of [1] to [13], which is at least one of tetracarboxylic dianhydrides.

[16] The liquid crystal aligning agent according to any one of [1] to [13], wherein the tetracarboxylic dianhydride is an aromatic tetracarboxylic dianhydride represented by the formula (H-1).

[17] Aromatics in which tetracarboxylic dianhydride is represented by formula (H-1), formula (H-5), formula (H-8) to formula (H-10) and formula (H-22) At least one of tetracarboxylic dianhydrides and formula (S-1), formula (S-6), formula (S-9) to formula (S-10), formula (S-21) to formula (S-22) ), Formula (S-30), formula (S-43) to formula (S-45), formula (S-48) and tetracarboxylic dianhydride other than aromatic represented by formula (S-52) The liquid crystal aligning agent of any one of [1]-[13] which is a mixture with at least 1 of these.

[18] A tetracarboxylic dianhydride other than aromatic is represented by formula (S-1), formula (S-6), formula (S-9), formula (S-45), formula (S-48) and formula The liquid crystal aligning agent as described in the item [17], which is at least one of the compounds represented by (S-52).

[19] The aromatic tetracarboxylic dianhydride is a compound represented by the formula (H-1), and the non-aromatic tetracarboxylic dianhydrides are the formula (S-1) and the formula (S-48). The liquid crystal aligning agent as described in the item [17], which is at least one of the compounds represented by:

[20] A liquid crystal alignment film formed by heating a coating film of the liquid crystal aligning agent according to any one of [1] to [19].

[21] A liquid crystal display device comprising a pair of substrates, a liquid crystal layer formed between the substrates, an electrode for applying a voltage to the liquid crystal layer, and a liquid crystal alignment film according to item [20].

  The liquid crystal aligning agent of this invention is a composition containing the at least 1 polymer chosen from the group which consists of a polyamic acid and its derivative (s). The derivatives of polyamic acid include 1) polyimide obtained by completely dehydrating and ring-closing reaction of polyamic acid, 2) partially imidized polyamic acid obtained by partially dehydrating and ring-closing reaction of polyamic acid, and 3) polyamic acid ester, 4) Polyamic acid-polyamide copolymer obtained by substituting a part of tetracarboxylic dianhydride with dicarboxylic acid, 5) Obtained by subjecting a part or all of this polyamic acid-polyamide copolymer to a dehydration ring-closing reaction. And polyamideimide. Of these, polyimide and partially imidized polyamic acid are preferable, and polyimide is more preferable. In the following description excluding examples, unless otherwise specified, “polyamic acid” is used as a general term for polyamic acid and its derivatives.

環Ｐはピリジン−２，５−ジイル、ピリダジン−３，６−ジイル、ピリミジン−２，５−ジイルまたはピラジン−２，５−ジイルであり、好ましくはピリジン−２，５−ジイルまたはピリダジン−３，６−ジイルである。そして、ｋは０または１である。即ち、ジアミン（Ｐ）は２環または３環の化合物であるが、２環であるとき環Ｐは、５位にアミノ基が結合しているピリジン−２，５−ジイル、または５位にアミノ基が結合しているピリミジン−２，５−ジイルである。 The polymer is a tetracarboxylic acid obtained by mixing at least one diamine selected from the group of diamines represented by the formula (P) or a mixture of the diamines (these) and other diamines not represented by the formula (P). It is a polyamic acid obtained by reacting with a dianhydride or a derivative thereof.

Ring P is pyridine-2,5-diyl, pyridazine-3,6-diyl, pyrimidine-2,5-diyl or pyrazine-2,5-diyl, preferably pyridine-2,5-diyl or pyridazine-3 , 6-Diyl. K is 0 or 1. That is, diamine (P) is a bicyclic or tricyclic compound, but when it is bicyclic, ring P is pyridine-2,5-diyl with an amino group bonded to the 5-position, or amino at the 5-position. Pyrimidine-2,5-diyl to which the group is attached.

Preferred examples of diamine (P) are shown below. Of these, diamine (P-5) and diamine (P-8) are more preferred.

  Diamine (P) can be produced by a known method. For example, a method as described in CN17333736A publication or CN101338462A publication can be used.

  The diamine that is a raw material for producing the polyamic acid used in the liquid crystal aligning agent of the present invention may be at least one diamine selected from the group of diamines (P), or other diamines other than these. At least one may be further included. That is, the proportion of the diamine selected from the diamine (P) group is preferably 10 to 100 mol%, and preferably 30 to 100 mol%, as a proportion of the diamine raw material used for producing the polyamic acid. More preferred. By using such a use ratio, a desired residual DC can be realized in the liquid crystal display element.

  The other diamines can be classified into two types depending on the structure. That is, when a skeleton connecting two amino groups is viewed as a main chain, a group branched from the main chain, that is, a diamine having a side chain group and a diamine having no side chain group. By reacting a diamine having a side chain group with tetracarboxylic dianhydride, a polyamic acid having a large number of side chain groups with respect to the main chain of the polymer is obtained. When a polyamic acid having a side chain group with respect to such a polymer main chain is used, the liquid crystal alignment film formed from the liquid crystal alignment agent containing this polymer can increase the pretilt angle in the liquid crystal display element. . That is, this side chain group is a group having an effect of increasing the pretilt angle. The side chain group having such an effect needs to be a group having 3 or more carbon atoms. Specific examples include alkyl having 3 or more carbon atoms, alkoxy having 3 or more carbon atoms, alkoxyalkyl having 3 or more carbon atoms, and A group having a steroid skeleton can be exemplified. A group having one or more rings, wherein the terminal ring has any one of alkyl having 1 or more carbon atoms, alkoxy having 1 or more carbon atoms and alkoxyalkyl having 2 or more carbon atoms as a substituent; It has an effect as a side chain group. The side chain group in the present invention is selected from these groups. In the following description, a diamine having such a side chain group may be referred to as a side chain diamine. Such a diamine having no side chain group may be referred to as a non-side chain diamine.

  Then, by properly using the side chain diamine and the non-side chain diamine, it is possible to cope with the pretilt angle required for each of the various display elements. That is, in the vertical electric field method represented by the TN method and the VA method, a relatively large pretilt angle is required, and therefore, a side chain type diamine is mainly used. At this time, in order to further control the pretilt angle, a non-side chain diamine may be used in combination. What is necessary is just to determine the compounding ratio of non-side chain type diamine and side chain type diamine according to the magnitude | size of the target pretilt angle. Of course, it is possible to use only a side chain type diamine by appropriately selecting a side chain group. In the lateral electric field method, since the pretilt angle is small and high liquid crystal orientation is required, at least one of non-side chain diamines may be used. As described above, the liquid crystal aligning agent of the present invention can be applied to any kind of liquid crystal display element.

Specific examples of the side chain group are as follows.
First, alkyl, alkyloxy, alkyloxyalkyl, alkylcarbonyl, alkylcarbonyloxy, alkyloxycarbonyl, alkylaminocarbonyl, alkenyl, alkenyloxy, alkenylcarbonyl, alkenylcarbonyloxy, alkenyloxycarbonyl, alkenylaminocarbonyl, alkynyl, Alkynyloxy, alkynylcarbonyl, alkynylcarbonyloxy, alkynyloxycarbonyl, alkynylaminocarbonyl and the like can be mentioned. Alkyl, alkenyl and alkynyl in these groups are all groups having 3 or more carbon atoms. However, in alkyloxyalkyl, it is sufficient if it has 3 or more carbon atoms as a whole. These groups may be linear or branched.

  Next, phenyl, phenylalkyl, phenylalkyloxy, phenyloxy, provided that the terminal ring has alkyl having 1 or more carbon atoms, alkoxy having 1 or more carbon atoms or alkoxyalkyl having 2 or more carbon atoms as a substituent. Phenylcarbonyl, phenylcarbonyloxy, phenyloxycarbonyl, phenylaminocarbonyl, phenylcyclohexyloxy, cycloalkyl having 3 or more carbon atoms, cyclohexylalkyl, cyclohexyloxy, cyclohexyloxycarbonyl, cyclohexylphenyl, cyclohexylphenylalkyl, cyclohexylphenyloxy, bis ( Cyclohexyl) oxy, bis (cyclohexyl) alkyl, bis (cyclohexyl) phenyl, bis (cyclohexyl) phenylalkyl, bis ( Kurohekishiru) oxycarbonyl, and bis (cyclohexyl) phenyloxycarbonyl and cyclohexyl bis (phenyl) group of a ring structure, such as oxycarbonyl,.

  Further, a group having two or more benzene rings, a group having two or more cyclohexane rings, or two or more groups composed of a benzene ring and a cyclohexane ring, wherein the bonding groups are independently a single bond, -O-, -COO-, -OCO-, -CONH-, or alkylene having 1 to 3 carbon atoms, the terminal ring is alkyl having 1 or more carbon atoms as a substituent, fluorine-substituted alkyl having 1 or more carbon atoms, carbon A ring assembly group having an alkoxy of several or more or an alkoxyalkyl having two or more carbons can be given. The upper limit of the carbon number of these substituents is not particularly limited, and may be determined in consideration of production costs and physical properties. A group having a steroid skeleton is also effective as a side chain group.

Preferable examples of the side chain diamine are diamines represented by formula (VIII) and formula (X) to formula (XIII).

In formula (VIII), ^{A 3} is a single bond, -O -, - CO -, - COO -, - OCO -, - CONH -, - CH 2 O -, - CF 2 O-, or 6 carbon atoms And any —CH ₂ — in the alkylene may be replaced by —O—, —CH═CH— or —C≡C—. Preferred examples of A ³ are a single bond, —O—, —COO—, —OCO—, —CH ₂ O—, and alkylene having 1 to 3 carbon atoms, and particularly preferred examples are a single bond, —O—, — _{COO -, - OCO -, -} CH 2 O -, - CH 2 - and _-CH 2 CH ₂ -. R ¹ is a group having a steroid skeleton, alkyl having 3 to 30 carbon atoms, phenyl having 1 to 30 carbon atoms or alkoxy having 1 to 30 carbon atoms as a substituent, or a group represented by the formula (IX) In the alkyl having 3 to 30 carbon atoms, any —CH ₂ — may be replaced by —O—, —CH═CH— or —C≡C—. Preferred examples of R ¹ are alkyl having 3 to 30 carbon atoms, alkyl having 1 to 30 carbon atoms or phenyl having 1 to 30 carbon atoms as a substituent, and a group represented by formula (IX). The bonding positions of the two amino groups with the benzene ring are preferably the 3-position and 5-position or the 2-position and 5-position when the bonding position of A ³ is the 1-position.

In the formula (IX), A ⁴ and A ⁵ are independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or alkyleneoxy having 1 to 3 carbon atoms, preferably a single bond or alkylene having 1 to 4 carbon atoms. Ring B and ring C are independently 1,4-phenylene or 1,4-cyclohexylene. R ² and R ³ are independently fluorine or methyl. f and g are each independently 0, 1 or 2, preferably 0. c, d and e are each independently an integer of 0 to 2, and the sum thereof is 1 or more. When c is 2, the two rings B may be the same or different, and the two A ⁴ may be the same linking group or different linking groups. When d is 2, the two A ⁵ groups may be the same linking group or different linking groups. And when e is 2, the two rings C may be the same or different. R ⁴ is alkyl having 1 to 30 carbons, alkoxy having 1 to 30 carbons, or alkoxyalkyl having 2 to 30 carbons, and in these alkyls, alkoxys and alkoxyalkyls, any hydrogen is replaced with fluorine. Also good. Preferred examples of R ⁴ are alkyl having 1 to 30 carbons and alkoxy having 1 to 30 carbons.

In formula (X) and formula (XI), R ⁵ is independently hydrogen or methyl. R ⁶ is hydrogen, alkyl having 1 to 20 carbons or alkenyl having 2 to 20 carbons. R ⁷ and R ⁸ are each independently alkyl having 1 to 20 carbons or phenyl. A ⁶ is independently a single bond, —CO— or —CH ₂ —. In the formula (X), it is preferable that one of the two “NH ₂ —Ph—A ⁶ —O—” is bonded to the 3-position of the steroid skeleton and the other is bonded to the 6-position. The coupling position of the benzene ring of the two amino groups is preferably both with respect to the binding position of A ^6, meta or para position. In the formula (XI), the bonding positions of the two “NH ₂ — (R ⁸ —) Ph—A ⁶ —O—” with the benzene ring are all meta-positions relative to the carbon to which the steroid skeleton is bonded. The para position is preferred. The coupling position of the benzene ring of the two amino groups is preferably both with respect to the binding position of A ^6, meta or para position.

In the formulas (XII) and (XIII), R ⁹ is alkyl having 1 to 30 carbons, and any —CH ₂ — in the alkyl is —O—, —CH═CH—, or —C≡C. It may be replaced with-. R ¹⁰ is alkyl having 6 to 22 carbon atoms, and R ¹¹ is alkyl having 1 to 22 carbon atoms. A ⁷ is independently —O— or alkylene having 1 to 6 carbons. A ⁸ represents a single bond or alkylene having 1 to 3 carbon atoms. Ring T is 1,4-phenylene or 1,4-cyclohexylene. h is 0 or 1. In the formula (XII), bonding position of the benzene ring of the two amino groups is preferably either a meta or para position with respect to the binding position of A ^7. In the formula (XIII), bonding position of the benzene ring of the two amino groups is preferably either a meta or para position with respect to the binding position of A ^7.

Specific examples of diamine (VIII) are shown below.

In the formulas (VIII-1) to (VIII-11), R ²³ is alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons, preferably alkyl having 3 to 25 carbons or 3 to 3 carbons. 25 alkoxy.

In Formula (VIII-12) to Formula (VIII-17), R ²⁵ is alkyl having 4 to 30 carbons, and preferably alkyl having 6 to 25 carbons. R ²⁶ is alkyl having 6 to 30 carbon atoms, preferably alkyl having 8 to 25 carbon atoms.

In the formula (VIII-18) to the formula (VIII-37), R ²⁷ is alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons, preferably alkyl having 3 to 25 carbons or 3 to 3 carbons. 25 alkoxy. R ²⁸ is hydrogen, fluorine, alkyl having 1 to 30 carbons, alkoxy having 1 to 30 carbons, —C≡N, —OCH ₂ F, —OCHF ₂ or —OCF ₃ , preferably ₃ to 25 carbons. Or alkyl having 3 to 25 carbon atoms.

  Among the above diamines (VIII-1) to diamines (VIII-43), diamines (VIII-1) to diamines (VIII-11) are preferable, and diamines (VIII-2) and diamines (VIII-4) to diamines ( VIII-6) is more preferable.

Specific examples of diamine (X) are shown below.

Specific examples of diamine (XI) are shown below.

Specific examples of diamine (XII) are shown below.

In formula (XII-1) to formula (XII-3), R ²⁹ is alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons, preferably alkyl having 3 to 30 carbons or 3 to 3 carbons. 30 alkoxy. In the formulas (XII-4) to (XII-8), R ³⁰ is alkyl having 1 to ³⁰ carbons or alkoxy having 1 to 30 carbons, preferably alkyl having 3 to 30 carbons or 3 to 3 carbons. 30 alkoxy.

Specific examples of diamine (XIII) are shown below.

In Formula (XIII-1) to Formula (XIII-3), R ³¹ is alkyl having 6 to 22 carbons, and preferably alkyl having 6 to 20 carbons. R ³² is alkyl having 1 to 22 carbons, preferably alkyl having 1 to 10 carbons.

  Among the specific examples of the side chain diamine, diamine (VIII-2), diamine (VIII-4) to diamine (VIII-6), diamine (XII-2), diamine (XII-4) and diamine (XII) -6) is preferred.

  When the side chain type diamine as described above is intended to develop a large pretilt angle in a liquid crystal display element, when the polymer used in the liquid crystal aligning agent of the present invention is produced, the ratio in the total amount of diamine is 1 to It is preferable to set it as 90 mol%, and it is more preferable to set it as 5-70 mol%.

Preferable examples of the diamine having no side chain group as described above, that is, a non-side chain diamine include compounds represented by the formulas (I) to (VII) and (XV).

In these formulas, X is a linear alkylene having 2 to 12 carbon atoms. Y is independently a single bond, —O—, —CO—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) _2- , -O- (CH ₂ ) _t -O-, -S-, -S-S-, -SO _2- , -S- (CH ₂ ) _t -S- or straight chain having 1 to 12 carbon atoms Chain alkylene, t is an integer of 1-12. Z ¹ and Z ² are hydrogen, but when Y is —NH—, —N (CH ₃ ) —, —CH ₂ —, —C (CH ₃ ) ₂ — or —C (CF ₃ ) ₂ —. They may be bonded together to form a single bond. Ring D is phenylene or 1,4-diazacyclohexylene. R ³³ and R ³⁴ are each independently alkyl or phenyl having 1 to 3 carbon atoms. A ³ is independently alkylene having 1 to 6 carbon atoms, phenylene, or alkyl-substituted phenylene. m is an integer of 1-10. Any hydrogen in the cyclohexane or benzene ring may be replaced with fluorine, methyl, trifluoromethyl, —OH, —COOH, —SO ₃ H, —PO ₃ H ₂ , benzyl or hydroxybenzyl.

Examples of diamine (I) are shown below.

Specific examples of diamine (II) are shown below.

Specific examples of diamine (III) are shown below.

Specific examples of diamine (IV) are shown below.

Specific examples of diamine (V) are shown below.

Specific examples of diamine (VI) are shown below.

Specific examples of diamine (VII) are shown below.

Specific examples of diamine (XV) are shown below.

  Among the above-mentioned non-side chain diamines, diamine (IV-1) to diamine (IV-5), diamine (IV-15) to diamine (IV-17), diamine (V-1) to diamine (V-12) ), Diamine (V-26), diamine (V-27), diamine (V-31), diamine (V-33), diamine (V-35) to diamine (V-37), diamine (VI-1) Diamine (VI-2), diamine (VI-6), diamine (VII-1) to diamine (VII-5) and diamine (XV-1) are preferred, and diamine (IV-1) and diamine (IV-2). ), Diamine (IV-15) to diamine (IV-17), diamine (V-1) to diamine (V-12), diamine (V-33), diamine (V-35) to diamine (V-37) , Diamine (VI-7), diamine (VII-2) and diamine (XV-1) Is more preferable.

  In consideration of adjusting the electrical characteristics such as ion density in the liquid crystal display element to a preferable range, such a non-side chain diamine is mol% in the total amount of diamine as a raw material of polyamic acid in the liquid crystal aligning agent of the present invention. The content is preferably 1 to 98%, more preferably 10 to 95%, and still more preferably 20 to 80%.

  Diamines other than the diamine (I) to diamine (VIII), diamine (X) to diamine (XIII), and diamine (XV) can be used as the diamine used in the present invention. Examples of such diamines include fluorene diamines having a fluorene ring and side chain diamines other than diamine (VIII) to diamine (XII).

これらの式において、Ｒ^３５およびＲ^３６はそれぞれ独立して炭素数３〜３０のアルキル基である。これらのジアミンは、本発明の液晶配向剤におけるポリアミック酸を製造する際に、本発明の効果が損なわれない程度の範囲で用いることができる。 Examples of the side chain diamine other than diamine (VIII) to diamine (XII) are diamine (1 ′) to diamine (8 ′).

In these formulas, R ³⁵ and R ³⁶ are each independently an alkyl group having 3 to 30 carbon atoms. These diamines can be used in such a range that the effects of the present invention are not impaired when the polyamic acid in the liquid crystal aligning agent of the present invention is produced.

  When producing a polyamic acid, a monoamine may be added to the diamine. By adding a monoamine, termination of the polymerization reaction when producing the polyamic acid can be caused, and further progress of the polymerization reaction can be suppressed. That is, the molecular weight of the obtained polymer (polyamic acid or derivative thereof) can be easily controlled, and for example, the coating properties of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. What is necessary is just to adjust the addition ratio of a monoamine suitably considering the molecular weight of the target polyamic acid. If the effects of the present invention are not impaired, two or more monoamines may be added. Examples of monoamines are aniline, 4-hydroxyaniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecyl. Amine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, and n-eicosylamine .

  In the present invention, when a diamine is reacted with tetracarboxylic dianhydride to obtain a polyamic acid, a mixture of a diamine selected from the diamine (P) group and other diamines as described above can be used. At this time, one of the preferable examples of the other diamine is at least one of side chain type diamines selected from the group of diamine (VIII) and diamine (X) to diamine (XIII). Another preferred example of the other diamines includes diamine (VIII) and at least one side chain diamine selected from the group of diamine (X) to diamine (XIII) and diamine (I) to diamine (VII) and diamine ( XV) is a mixture with at least one non-side chain diamine selected from the group of XV). Said [4]-[7] term is a preferable example of the combination of the diamine selected from the group of diamine (P), a side chain type diamine, and a non-side chain type diamine.

  In the present invention, the polyamic acid obtained by reacting the mixed diamine with tetracarboxylic acid as described above may be used as the polymer component, or a mixture of polyamic acids of different raw materials may be used as the polymer component. One preferred example of the mixture of polyamic acids is at least one diamine selected from the group of diamine (P) and a side chain diamine selected from the group of diamine (VIII) and diamine (X) to diamine (XIII) Or a mixture obtained by further adding at least one non-side chain diamine selected from the group consisting of diamine (I) to diamine (VII) and diamine (XV) to this diamine mixture. A mixture of at least one of the non-side chain diamines or at least one of the non-side chain diamines and at least one diamine selected from the group of diamines (P) Is a mixture with a polyamic acid obtained by reacting with a tetracarboxylic dianhydride. The polymers shown in the items [8] to [11] correspond to these polyamic acid mixtures.

  Another preferred example of the mixture of polyamic acids is at least one diamine selected from the group of diamine (P) and a non-side chain selected from the group of diamine (I) to diamine (VII) and diamine (XV) A polyamic acid obtained by reacting a mixture of at least one type diamine with tetracarboxylic dianhydride, and at least a side chain type diamine selected from the group consisting of diamine (VIII) and diamine (X) to diamine (XIII) It is a mixture of polyamic acid obtained by reacting one or a mixture of at least one of the side chain diamines and at least one of the non-side chain diamines with tetracarboxylic dianhydride. The polymers shown in the items [12] and [13] correspond to these polyamic acid mixtures.

  The tetracarboxylic dianhydride used in the present invention may be one compound or a mixture of two or more compounds. Examples of tetracarboxylic dianhydrides include aromatic tetracarboxylic dianhydrides and non-aromatic tetracarboxylic dianhydrides. Examples of non-aromatic tetracarboxylic dianhydrides are alicyclic tetracarboxylic dianhydrides and aliphatic tetracarboxylic dianhydrides. The aromatic tetracarboxylic dianhydride means a compound obtained by dehydration of four carboxyl groups bonded to an aromatic group. An alicyclic tetracarboxylic dianhydride means a compound obtained by dehydration of four carboxyl groups bonded to a cyclic aliphatic group. An aliphatic tetracarboxylic dianhydride means a compound obtained by dehydration of four carboxyl groups bonded to a chain aliphatic group.

Examples of aromatic tetracarboxylic dianhydrides are shown below.

  Among the above aromatic tetracarboxylic dianhydrides, acid anhydride (H-1), acid anhydride (H-5), acid anhydride (H-8) to acid anhydride (H-10) and acid Anhydride (H-22) is preferred, and acid anhydride (H-1) is particularly preferred.

Examples of alicyclic tetracarboxylic dianhydrides are shown below.

  Among the alicyclic tetracarboxylic dianhydrides, acid anhydride (S-1) to acid anhydride (S-5), acid anhydride (S-8) to acid anhydride (S-30) and Acid anhydride (S-35) to acid anhydride (S-46) are preferable, and acid anhydride (S-1) is more preferable.

Examples of aliphatic tetracarboxylic dianhydrides are shown below.

  Of the above aliphatic tetracarboxylic dianhydrides, acid anhydride (S-6), acid anhydride (S-48) and acid anhydride (S-52) are preferred.

  When manufacturing a polyamic acid, you may use it, adding a dicarboxylic acid anhydride to tetracarboxylic dianhydride. By doing so, termination of the polymerization reaction at the time of producing the polyamic acid can be caused, and further progress of the polymerization reaction can be suppressed. That is, the molecular weight of the resulting polymer (polyamic acid) can be easily controlled, and for example, the coating properties of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. What is necessary is just to adjust suitably the addition ratio of dicarboxylic acid anhydride in consideration of the molecular weight of the target polyamic acid. Further, two or more kinds of dicarboxylic acid anhydrides may be added as long as the effects of the present invention are not impaired. Examples of dicarboxylic anhydrides are maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl succinic anhydride And cyclohexane acid anhydride.

  In the present invention, a monoisocyanate compound may be further added when producing a polyamic acid. By adding a monoisocyanate compound, the terminal of the resulting polyamic acid is modified, and the molecular weight is adjusted. By using this terminal-modified polyamic acid, for example, the coating properties of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. The addition amount of the monoisocyanate compound is preferably 1 to 10 mol% with respect to the total amount of diamine and tetracarboxylic dianhydride from the above viewpoint. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

  The polyamic acid used in the present invention can be produced in the same manner as a known polyamic acid used for forming a polyimide film. The total amount of tetracarboxylic dianhydride is preferably approximately equimolar to the total number of moles of diamine (molar ratio of about 0.9 to 1.1).

  The molecular weight of the polyamic acid is preferably a weight average molecular weight (Mw) in terms of polystyrene of 10,000 to 500,000, and more preferably 20,000 to 200,000. The molecular weight of the polyamic acid can be determined from a measured value by a gel permeation chromatography (GPC) method.

  The presence of polyamic acid can be confirmed by analyzing the solid content obtained by precipitation with a large amount of poor solvent by IR or NMR. The raw material used can be confirmed by decomposing polyamic acid with an aqueous solution of strong alkali such as KOH and NaOH and analyzing the extract of the decomposed product with an organic solvent by GC, HPLC or GC-MS. .

  The liquid crystal aligning agent of this invention may further contain other components other than the said polyamic acid. The other component may be one type or two or more types.

  For example, the liquid crystal aligning agent of the present invention may further contain an alkenyl-substituted nadiimide compound from the viewpoint of stabilizing the electrical characteristics of the liquid crystal display element over a long period of time. The content in the case of adding the alkenyl-substituted nadiimide compound is preferably 0.01 to 0.50 as a weight ratio with respect to the polyamic acid in the liquid crystal aligning agent.

  The alkenyl-substituted nadiimide compound is preferably a compound that can be dissolved in a solvent that dissolves the polyamic acid or derivative thereof used in the present invention. A particularly preferred example of such an alkenyl-substituted nadiimide compound is a bis {4- (allylbicyclo [2.2.1] hept-5-ene-2,3-dicarboximide represented by the formula (Ina-1). ) Phenyl} methane, N, N′-m-xylylene-bis (allylbicyclo [2.2.1] hept-5-ene-2,3-dicarboximide) represented by the formula (Ina-2), And N, N′-hexamethylene-bis (allylbicyclo [2.2.1] hept-5-ene-2,3-dicarboximide) represented by the formula (Ina-3).

  Such an alkenyl-substituted nadiimide compound, for example, as described in Japanese Patent No. 2729565, holds an alkenyl-substituted nadic acid anhydride derivative and a diamine at a temperature of 80 to 220 ° C. for 0.5 to 20 hours, A compound obtained by reacting or a commercially available compound can be used.

  For example, the liquid crystal aligning agent of this invention may further contain the compound which has radically polymerizable unsaturated double bonds other than an alkenyl substituted nadiimide compound from a viewpoint of stabilizing the electrical property of a liquid crystal display element for a long period of time. . The content in the case of using the compound having a radical polymerizable unsaturated double bond is preferably 0.01 to 0.50 in a weight ratio with respect to the polyamic acid.

  Examples of the compound having a radical polymerizable unsaturated double bond include (meth) acrylic acid esters, (meth) acrylic acid derivatives such as (meth) acrylic acid amide, and bismaleimide. A (meth) acrylic acid derivative having two or more bonds is more preferred.

  For example, the liquid crystal aligning agent of this invention may further contain the oxazine compound from a viewpoint of the long-term stability of the electrical property in a liquid crystal display element. The content in the case of adding the oxazine compound is preferably 0.01 to 0.20 in terms of a weight ratio to the polyamic acid.

Examples of the oxazine compound include compounds represented by the following general formulas (a) to (f).

In the above formula, ^{R 1} and ^{R 2} represents an organic group having 1 to 30 carbon atoms. R ^{3 to} R ⁶ represent hydrogen or a hydrocarbon group having 1 to 6 carbon atoms. X is a single bond, —O—, —S—, —S—S—, —SO ₂ —, —CO—, —CONH—, —NHCO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, — (CH ₂ ) _m —, —O— (CH ₂ ) _m —O—, or —S— (CH ₂ ) _m —S—. Here, m is an integer of 1-6. Y independently represents a single bond, —O—, —S—, —CO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ — or alkylene having 1 to 3 carbon atoms. Any hydrogen in the benzene ring and naphthalene ring may be replaced with fluorine, methyl, —OH, —COOH, —SO ₃ H, or —PO ₃ H ₂ .

  The oxazine compound can be produced by the same method as described in International Publication No. 2004/009708, JP-A-11-12258, and JP-A-2004-352670.

In addition, from the viewpoint of long-term stability of electrical characteristics in the liquid crystal display element, the liquid crystal display device may further contain an oxazoline compound having the following oxazoline structure. Moreover, the compound which has an oxiranyl group can also be added, and polymers other than a polyamic acid can also be added. Furthermore, various additives, for example, 1) a surfactant in accordance with the purpose when improvement in coatability is desired, 2) an antistatic agent when improvement in antistatic is required, and 3) adhesion to the substrate Further, when it is desired to improve the rubbing resistance, a silane coupling agent or a titanium-based coupling agent can be added, and 4) an imidization catalyst can be added when the imidization proceeds at a low temperature.

  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 said polyamic acid density | concentration. This solvent can be used without any particular limitation as long as it has the ability to dissolve the polymer component. That is, it can be appropriately selected from many solvents including those usually used in the production process and application of polymer components such as polyamic acid and soluble polyimide according to the purpose of use. This solvent may be used alone or in combination with a plurality of solvents.

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

  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 monomethyl ether, propylene glycol monobutyl ether, dialkyl malonate such as diethyl malonate, dipropylene glycol monomethyl Dipropylene glycol monoalkyl ethers such as ethers and esters such as these acetates Compounds, and the like.

  Among these, particularly preferred solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, dimethylimidazolidinone, γ-butyrolactone, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl. Ether, and dipropylene glycol monomethyl ether.

  In the present invention, the concentration of the polymer component containing the polyamic acid in the liquid crystal aligning agent is not particularly limited, but is preferably 0.1 to 40% by weight. When this liquid crystal aligning agent is applied to a substrate, an operation of previously diluting a polymer component contained for adjusting the film thickness with a solvent may be required. At this time, from the viewpoint of adjusting the viscosity of the liquid crystal aligning agent to a viscosity suitable for easily mixing the solvent with the liquid crystal aligning agent, the concentration of the polymer component is preferably 40% by weight or less.

  The concentration of the polymer component in the liquid crystal aligning agent may be adjusted depending on the method of applying 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 dipping and ink jet methods may further reduce the concentration. On the other hand, when the concentration of the polymer component is 0.1% by weight or more, the film 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 lower 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 alignment film of the present invention is a film formed by heating the coating film of the liquid crystal aligning agent of the present invention described 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.

  Firing of the coating film can be performed under conditions necessary for the polyamic acid to exhibit dehydration and ring closure reactions. As 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-treating in an oven or an infrared furnace, a method of heat-treating 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, vapor cleaning, and ultrasonic cleaning. These methods may be performed alone or in combination. The cleaning liquid is pure water, various alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, aromatic hydrocarbons such as benzene, toluene, 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 contains a pair of substrates and liquid crystal molecules, a liquid crystal layer formed between the pair of substrates, an electrode for applying a voltage to the liquid crystal layer, and the liquid crystal molecules aligned in a predetermined direction. And the liquid crystal alignment film of the present invention.

  The glass substrate described above in 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 in the liquid crystal alignment film of the present invention can be used as the electrode. it can. The liquid crystal layer is formed of a liquid crystal composition that is sealed between substrates having a liquid crystal alignment film surface inside.

  The liquid crystal composition to be used 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 2001-48 It disclosed in 22 JP liquid crystal composition and the like are.

  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 Unexamined Patent Publication Nos. 10-287874, 10-287875, 10-291945, 11-029581, 11-080049, 2000-256307, 2001 Examples thereof include liquid crystal compositions disclosed in Japanese Patent Application Publication No. -019655, Japanese Patent Application Laid-Open No. 2001-072626, Japanese Patent Application Laid-Open No. 2001-192657, and the like.

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

  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.

  A liquid crystal display element for a horizontal electric field method may not exhibit a relatively large pretilt angle. Therefore, a liquid crystal alignment film formed from a liquid crystal aligning agent containing a non-side chain type polyamic acid obtained by using a non-side chain type diamine is suitably used for a liquid crystal display element for a horizontal electric field mode.

  A liquid crystal display element for a vertical electric field system requires a relatively large pretilt angle. Therefore, a liquid crystal alignment film formed from a liquid crystal alignment agent containing a side chain type polyamic acid obtained by using a side chain type diamine or a diamine mixture containing the same is suitably used for a liquid crystal display element for a vertical electric field mode. It is done.

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

  The liquid crystal display element of the present invention may further include elements other than the above-described components. As such other components, the liquid crystal display element of the present invention is mounted with components usually used for liquid crystal display elements such as a polarizing plate (polarizing film), a wave plate, a light scattering film, and a drive circuit. May be.

The present invention is illustrated by examples. The compounds used in the examples are as follows.
<Tetracarboxylic dianhydride>
Acid anhydride (H-1): pyromellitic dianhydride acid anhydride (S-1): 1,2,3,4-cyclobutanetetracarboxylic dianhydride:
Acid anhydride (S-48): ethylenediaminetetraacetic acid dianhydride:

<Diamine>
Diamine (P-5): 2,5-bis (4-aminophenyl) pyridinediamine (P-8): 2,5-bis (4-aminophenyl) pyrimidinediamine (V-1): 4,4′- Diaminodiphenylmethane
Diamine (V-7): 4,4′-diaminodiphenylethanediamine (VI-7): 1,4-bis (4-aminophenyl) -1,4-diazacyclohexanediamine (XII-2-1) ( R ²⁹ = n-heptyl): 1,1-bis (4- (4-aminophenylmethyl) phenyl) -4-n-heptylcyclohexanediamine (XII-4-1) (R ³⁰ = n-pentyl): 1 , 1-bis (4- (4-aminophenoxy) phenyl) -4- (n-pentylcyclohexyl) cyclohexanediamine (XII-6-1) (R ³⁰ = n-heptyl): 1,1-bis (4- (4-Aminophenoxy) phenyl) -4- (2- (n-heptylcyclohexyl) ethyl) cyclohexane DAPY: 2,6-diaminopyridine DAPM: 2,4-diaminopyrimidine PPD 2-amino-5- (4-aminophenyl) pyrimidine

<Solvent>
NMP: N-methyl-2-pyrrolidone
BC: Butyl cellosolve (ethylene glycol monobutyl ether)

<Synthesis of polyamic acid>
[Synthesis Example 1]
1.673 g of diamine (P-5) and 30.0 g of dehydrated NMP were placed in a 100 mL four-necked flask equipped with a thermometer, a stirrer, a raw material charging inlet and a nitrogen gas inlet, and dissolved under stirring in a dry nitrogen stream. . Next, 0.6984 g of acid anhydride (H-1), 0.6280 g of acid anhydride (S-1), and 70.0 g of dehydrated NMP were added and reacted for 15 hours in a room temperature environment. When the reaction temperature rose during the reaction, the reaction temperature was kept at about 70 ° C. or lower for the reaction. To the resulting solution, 10.0 g of BC was added to obtain a polyamic acid solution having a concentration of 6% by weight. This polyamic acid is designated as PA1. The weight average molecular weight of PA1 was 27300.

  The weight average molecular weight of the polyamic acid was diluted with a phosphoric acid-DMF mixed solution (phosphoric acid / DMF = 0.6 / 100: weight ratio) so that the polyamic acid concentration was about 2% by weight. Using a 2695 separation module / 2414 differential refractometer (manufactured by Waters), the above mixed solution was measured by a GPC method using a developing agent, and was calculated by polystyrene conversion. In addition, the column used HSPgel RT MB-M (product made from Waters), and measured it on the conditions of column temperature 50 degreeC and the flow rate of 0.40 mL / min.

[Synthesis Examples 2 to 12]
Polyamic acid solutions (PA2) to (PA12) were prepared according to Synthesis Example 1 except that tetracarboxylic dianhydride and diamine were changed as shown in Table 1. The results are summarized in Table 1 including Synthesis Example 1.

<Table 1>

[Comparative Synthesis Examples 1 to 9]
Polyamic acid solutions (PA13) to (PA21) were prepared according to Synthesis Example 1 except that tetracarboxylic dianhydride and diamine were changed as shown in Table 1. The results are summarized in Table 2.

<Table 2>

  The polyamic acid solution (PA7) having a concentration of 6% by weight prepared in Synthesis Example 7 and the polyamic acid solution (PA13 to PA15) having a concentration of 6% by weight prepared in Comparative Synthesis Examples 1 to 3 are in a weight ratio of 20/80 (the former / the latter). ) To obtain liquid crystal aligning agents (PA22 to PA24). The composition ratios of PA22 to PA24 are summarized in Table 3.

<Table 3>

  Bis {4- (allylbicyclo [2.2.1] hept-5-ene-2,3-dicarboximide) phenyl} methane was added to the polyamic acid solution (PA7) having a concentration of 6% by weight prepared in Synthesis Example 7. , 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 4,4-methylenebis (N, N-diglycidylaniline) or N, N- (1,2-dihydroxyethylene) bisacrylamide per polymer weight, respectively 10 weight% was added and it was set as the liquid crystal aligning agent (PA25-PA28). The composition table of PA25 to PA28 is summarized in Table 4.

<Table 4>

[Example 1]
<Production of liquid crystal display element>
The polyamic acid solution (PA1) having a concentration of 6% by weight synthesized in Synthesis Example 1 was diluted to 4% by weight by adding a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a liquid crystal aligning agent. . Using the obtained liquid crystal aligning agent, a liquid crystal display element was produced as follows.

<Method for manufacturing liquid crystal display element>
The liquid crystal aligning agent was applied to two glass substrates with an ITO electrode with a spinner to form a film with a thickness of 100 nm. After coating, the film was heated and dried at 80 ° C. for about 1 minute, and then heat-treated at 210 ° C. for 15 minutes to form a liquid crystal alignment film. Using a rubbing treatment device manufactured by Iinuma Gauge Co., Ltd., with a rubbing cloth (hair length 1.8 mm: rayon) push-in amount of 0.40 mm, stage moving speed 60 mm / sec, roller rotation speed 1,000 rpm The obtained liquid crystal alignment film was rubbed. Thereafter, the liquid crystal alignment film was ultrasonically cleaned in ultrapure water for 5 minutes and then dried in an oven at 120 ° C. for 30 minutes.

  One glass substrate was sprayed with a gap material of 4 μm, and the surface on which the liquid crystal alignment film was formed was placed inside so that the rubbing direction was antiparallel, then sealed with an epoxy curing agent, and an anti-gap with a gap of 4 μm. A parallel cell was produced. The liquid crystal composition shown below was injected into the cell, and the injection port was sealed with a photocuring agent. Next, a heat treatment was performed at 110 ° C. for 30 minutes to manufacture a liquid crystal display element.

[Examples 2 to 19]
A polyamic acid solution (PA2 to PA12 and PA22 to PA28) having a concentration of 6% by weight described in Tables 1, 3 and 4 was added to a mixed solvent of NMP / BC = 1/1 (weight ratio) to give a total of 4% by weight. To obtain a liquid crystal aligning agent. A liquid crystal display element was produced in the same manner as in Example 1 using the obtained liquid crystal aligning agent.

[Comparative Examples 1 to 9]
A polyamic acid solution (PA13 to PA21) having a concentration of 6% by weight shown in Table 2 was diluted to 4% by weight by adding a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a liquid crystal aligning agent and did. A liquid crystal display element was produced in the same manner as in Example 1 using the obtained liquid crystal aligning agent.

<Evaluation of electrical characteristics>
About the liquid crystal display element produced in Examples 1-19 and Comparative Examples 1-9, the measurement of residual DC was performed as follows.

1) Measurement of residual DC After a DC voltage of 3 V was superimposed on a 30 Hz, 3 V rectangular wave for 30 minutes, the flicker erasing voltage after 10 minutes was measured, and the absolute value of this value was defined as the residual DC. In addition, in the test method of the Example of this invention, it can be said that residual DC is favorable if it is a value of 10 mV or less.

<Table 5>

  As shown in Table 5, when a polyamic acid is produced using diamine (P) as a raw material and a liquid crystal aligning agent containing this is prepared, a liquid crystal display having a liquid crystal aligning film obtained from this liquid crystal aligning agent In the element, the effect of reducing the residual DC is remarkable.

Claims (21)

Selected from the group consisting of polyamic acid obtained by reacting diamine represented by formula (P) or a mixture of diamine represented by formula (P) and other diamine with tetracarboxylic dianhydride and derivatives thereof Liquid crystal aligning agent containing at least one polymer

Wherein ring P is pyridine-2,5-diyl, pyridazine-3,6-diyl, pyrimidine-2,5-diyl or pyrazine-2,5-diyl; k is 0 or 1; When k = 0, ring P is pyridine-2,5-diyl or pyrimidine-2,5-diyl, and the binding position of the amino group in these rings is the 5-position. The liquid crystal aligning agent of Claim 1 whose diamine represented by Formula (P) is at least 1 of the diamine represented by Formula (P-1)-Formula (P-10).

  The liquid crystal aligning agent of Claim 2 whose diamine represented by Formula (P) is at least 1 of the diamine represented by Formula (P-5) and Formula (P-8). The other diamine is at least one diamine selected from the group of diamines having a side chain group represented by formula (VIII) and formula (X) to formula (XIII). The liquid crystal aligning agent according to item:

In formula (VIII), ^{A 3} is a single bond, -O -, - CO -, - COO -, - OCO -, - CONH -, - CH 2 O -, - CF 2 O-, or 6 carbon atoms Wherein any —CH ₂ — in the alkylene may be replaced by —O—, —CH═CH—, or —C≡C—; R ¹ is a group having a steroid skeleton, 3 carbon atoms An alkyl having 1 to 30 carbon atoms, phenyl having 1 to 30 carbon atoms or phenyl having 1 to 30 carbon atoms as a substituent, or a group represented by formula (IX), wherein the alkyl having 3 to 30 carbon atoms is Any —CH ₂ — may be replaced by —O—, —CH═CH— or —C≡C—:

In the formula (IX), A ⁴ and A ⁵ are independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or ring B and ring C are each independently 1,4-phenylene or 1,4-cyclohexylene; R ² and R ³ are each independently fluorine or methyl; And f and g are independently 0, 1 or 2; c, d and e are independently integers of 0 to 2 and their sum is 1 or more; c is 2 Sometimes the two rings B may be the same or different and the two A ⁴ may be the same or different linking groups; when d is 2, the two A ⁵ are They may be the same or different linking groups; when e is 2, One of the ring C may be the same or different; R ⁴ is an alkoxyalkyl of the alkoxy or C2-30 1-30 alkyl, carbon atoms having 1 to 30 carbon atoms, these alkyl, alkoxy and In alkoxyalkyl, any hydrogen may be replaced with fluorine:

In Formula (X) and Formula (XI), R ⁵ is independently hydrogen or methyl, R ⁶ is hydrogen, alkyl having 1 to 20 carbons or alkenyl having 2 to 20 carbons, R ⁷ and R ⁸ is independently alkyl having 1 to 20 carbons or phenyl, and A ⁶ is independently a single bond, —CO— or —CH ₂ —:

In Formula (XII) and Formula (XIII), R ⁹ is methyl or alkyl having 2 to 30 carbons, and any —CH ₂ — in the alkyl is —O—, —CH═CH— or —C R ¹⁰ is alkyl having 6 to 22 carbon atoms; R ¹¹ is alkyl having 1 to 22 carbon atoms; A ⁷ is independently —O— or 1 to carbon atoms. 6 is alkylene; A ⁸ is a single bond or alkylene having 1 to 3 carbon atoms; ring T is 1,4-phenylene or 1,4-cyclohexylene; h is 0 or 1. Other diamines represented by formula (VIII-2), formula (VIII-4) to formula (VIII-6), formula (XII-2), formula (XII-4) and formula (XII-6) The liquid crystal aligning agent of Claim 4 which is at least 1 selected from:

In these formulas, R ²³ , R ²⁹ and R ³⁰ are independently alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons. The other diamine does not have at least one selected from the group of diamines having a side chain group according to claim 4 and the side chain groups represented by formulas (I) to (VII) and (XV). The liquid crystal aligning agent of any one of Claims 1-3 which is a mixture with at least 1 selected from the group of diamine:

In these formulas, X is a linear alkylene having 2 to 12 carbon atoms; Y is independently a single bond, —O—, —CO—, —NH—, —N (CH ₃ ) —, —CONH—. , —NHCO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —O— (CH ₂ ) _t —O—, —S—, —S—S—, —SO ₂ —, —S— (CH ₂ ) _t —S— or a linear alkylene having 1 to 12 carbon atoms, t is an integer of 1 to 12; Z ¹ and Z ² are hydrogen, but Y is —NH When-, -N (CH ₃ )-, -CH _2- , -C (CH ₃ ) ₂ -or -C (CF ₃ ) _2- , they may combine with each other to form a single bond; is phenylene or ^{1,4-diaza-cyclohexylene;} alkyl or phenyl ^{R 33} and ^{R 34} having 1 to 3 carbon atoms independently There; A ³ is independently an alkylene having 1 to 6 carbon atoms, be phenylene or alkyl-substituted phenylene; m is an integer from 1 to 10; cyclohexane ring or arbitrary hydrogen of benzene ring, fluorine, methyl , Trifluoromethyl, —OH, —COOH, —SO ₃ H, —PO ₃ H ₂ , benzyl or hydroxybenzyl. The other diamine is represented by the formula (VIII-2), the formula (VIII-4) to the formula (VIII-6), the formula (XII-2), the formula (XII-4) and the formula (XII-6). At least one selected from diamines having a chain group, and Formula (IV-1), Formula (IV-2), Formula (IV-15) to Formula (IV-17), Formula (V-1) to Formula ( V-12), Formula (V-33), Formula (V-35) to Formula (V-37), Formula (VI-7), Formula (VII-2), and Formula (XV-1). The liquid crystal aligning agent of Claim 6 which is a mixture with at least 1 selected from the diamine which does not have a side chain group.

In these formulas, R ²³ , R ²⁹ and R ³⁰ are independently alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons.

  The polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to claim 2, and the group of diamines having a side chain group according to claim 4. A polyamic acid obtained by reacting a mixture with at least one selected from tetracarboxylic dianhydride or a derivative thereof, and at least one selected from the group of diamines having no side chain group according to claim 6. The liquid crystal aligning agent of Claim 1 which is a mixture with the polyamic acid obtained by making one react with tetracarboxylic dianhydride or its derivative (s).   The polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to claim 2, and the group of diamines having a side chain group according to claim 4. A polyamic acid obtained by reacting a mixture with at least one selected from tetracarboxylic dianhydride or a derivative thereof, and at least one selected from the group of diamines having no side chain group according to claim 6. And a mixture of at least one selected from the group of diamines represented by formulas (P-1) to (P-10) with tetracarboxylic dianhydride, or a mixture with a polyamic acid or a derivative thereof The liquid crystal aligning agent of Claim 1 which is.   The polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to claim 2, and the group of diamines having a side chain group according to claim 4. A polyamic acid or a derivative thereof obtained by reacting a mixture of at least one selected from the group consisting of at least one selected from the group consisting of diamines having no side chain group and tetracarboxylic dianhydride according to claim 6 with a tetracarboxylic dianhydride The liquid crystal aligning agent of Claim 1 which is a mixture with said polyamic acid obtained by making at least 1 of the diamine which does not have the said side chain group react with tetracarboxylic dianhydride, or its derivative (s).   The polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to claim 2, and the group of diamines having a side chain group according to claim 4. A polyamic acid or a derivative thereof obtained by reacting a mixture of at least one selected from the group consisting of at least one selected from the group consisting of diamines having no side chain group and tetracarboxylic dianhydride according to claim 6 with a tetracarboxylic dianhydride A mixture of at least one selected from the group of diamines having no side chain group and at least one selected from the group of diamines represented by formulas (P-1) to (P-10) The liquid crystal aligning agent of Claim 1 which is a mixture with the polyamic acid obtained by making it react with carboxylic dianhydride or its derivative (s).   The polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to claim 2, and diamine having no side chain group according to claim 6. A polyamic acid obtained by reacting a mixture of at least one selected from the group with tetracarboxylic dianhydride or a derivative thereof, and at least one selected from the group of diamines having side chain groups according to claim 4 The liquid crystal aligning agent of Claim 1 which is a mixture with the polyamic acid obtained by making one react with tetracarboxylic dianhydride or its derivative (s).   The polymer is at least one selected from the group of diamines represented by formula (P-1) to formula (P-10) according to claim 2, and diamine having no side chain group according to claim 6. A polyamic acid obtained by reacting a mixture of at least one selected from the group with tetracarboxylic dianhydride or a derivative thereof, and at least one selected from the group of diamines having side chain groups according to claim 4 And a polyamic acid obtained by reacting a mixture of at least one selected from the group of diamines having no side chain group with tetracarboxylic dianhydride or a derivative thereof. The liquid crystal aligning agent of description.   The tetracarboxylic dianhydride is a mixture of at least one of the aromatic tetracarboxylic dianhydrides or at least one of the aromatic tetracarboxylic dianhydrides and at least one of the non-aromatic tetracarboxylic dianhydrides. The liquid crystal aligning agent of any one of Claims 1-13. Aromatic tetracarboxylic acid in which tetracarboxylic dianhydride is represented by formula (H-1), formula (H-5), formula (H-8) to formula (H-10) and formula (H-22) The liquid crystal aligning agent of any one of Claims 1-13 which is at least 1 of a dianhydride.

The liquid crystal aligning agent of any one of Claims 1-13 whose tetracarboxylic dianhydride is an aromatic tetracarboxylic dianhydride represented by a formula (H-1).

Aromatic tetracarboxylic acid in which tetracarboxylic dianhydride is represented by formula (H-1), formula (H-5), formula (H-8) to formula (H-10) and formula (H-22) At least one of dianhydrides, Formula (S-1), Formula (S-6), Formula (S-9) to Formula (S-10), Formula (S-21) to Formula (S-22), Formula (S-30), at least one of tetracarboxylic dianhydrides other than aromatic represented by formula (S-43) to formula (S-45), formula (S-48) and formula (S-52) The liquid crystal aligning agent of any one of Claims 1-13 which is a mixture with one.

  Non-aromatic tetracarboxylic dianhydrides are represented by formula (S-1), formula (S-6), formula (S-9), formula (S-45), formula (S-48) and formula (S- The liquid crystal aligning agent of Claim 17 which is at least 1 of the compound represented by 52).   The aromatic tetracarboxylic dianhydride is a compound represented by the formula (H-1), and the non-aromatic tetracarboxylic dianhydrides are represented by the formula (S-1) and the formula (S-48). The liquid crystal aligning agent according to claim 17, which is at least one of the following compounds.   The liquid crystal aligning film formed by heating the coating film of the liquid crystal aligning agent of any one of Claims 1-19.   The liquid crystal display element which has a pair of board | substrate, the liquid crystal layer formed between this board | substrate, the electrode which applies a voltage to a liquid crystal layer, and the liquid crystal aligning film of Claim 20.