JP5407261B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention mainly contains a polyamic acid or a derivative thereof obtained by reacting a diamine mixture composed of 3,5-diamino-1,2,4-triazole and a specific diamine with tetracarboxylic dianhydride. The present invention relates to a liquid crystal aligning agent.

  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.

  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.

  Moreover, generation | occurrence | production of the amount of impurity ions in a liquid crystal display element is mentioned as one of the parameter | index showing the performance of another liquid crystal display element. This amount of impurity ions is generally referred to as ion density (Non-Patent Document 1), and can be measured and quantified using a Toyo Technica Corporation liquid crystal evaluation device or the like. It is often reported that when the numerical value of the ion density is large, an afterimage is generated at the boundary between pixels even though the voltage is turned off.

Japanese Examined Patent Publication No. 63-21907 JP-A-6-160878 JP-A-9-15650 Liquid crystal Vol.6 No.4 P44-P53.

  An object of the present invention is to provide a liquid crystal alignment film having a high voltage holding ratio, a low ion density, and a low residual DC, and to provide a liquid crystal alignment agent capable of forming this liquid crystal alignment film. It is another object of the present invention to provide a liquid crystal display element in which seizure hardly occurs.

The present inventors have intensively studied to solve the above problems, and use a diamine mixture composed of a 3,5-diamino-1,2,4-triazole derivative and a specific diamine as a diamine that is a polymer raw material. Thus, it was found that the liquid crystal alignment film made of the obtained polymer has a high voltage holding ratio, a low ion density, and a low residual DC when used in a liquid crystal display element. Patent Document 4 discloses an alignment film using a polyamic acid made from a diamine containing nitrogen in addition to an amino group, and this diamine contains 3,5-diamino-1,2,4-triazole. However, this publication does not disclose a specific example in which a diamine containing nitrogen other than this amino group and another diamine are used in combination, and the effect thereof is also partially transmitted in STN and NTN liquid crystal displays. However, only the improvement of the so-called crosstalk is shown.
JP-A-5-249473

ここに、Ｌ^１は水素、炭素数１〜４のアルキル、フェニルまたはベンジルであり；Ｘ^１は炭素数２〜１２の直鎖アルキレンであり；Ｘ^２は炭素数１〜１２の直鎖アルキレンであり；Ｘ^３、Ｘ^４およびＸ^５は独立して単結合、−Ｏ−、−ＣＯ−、−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、そして式（VI）におけるＸ^４および式（VII）におけるＸ^５はそれぞれ同一でも異なってもよく；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、−ＣＨ_３、−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。 The present invention is shown in the following item [1].
[1] Contains at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a mixture of a diamine represented by the formula (a) and another diamine with tetracarboxylic dianhydride and a derivative thereof. The other diamine is at least one selected from the group of non-side chain diamines represented by formula (I) to formula (VII), alkyl having 3 or more carbon atoms, and having 3 or more carbon atoms. Alkoxy, an alkoxyalkyl having 3 or more carbon atoms, a group having a steroid skeleton, and a ring-containing group having, as a substituent, an alkyl having 3 or more carbon atoms, an alkoxy having 3 or more carbon atoms or an alkoxyalkyl having 3 or more carbon atoms in the terminal ring At least one of the side chain diamines having a side chain group selected from: or at least one of the non-side chain diamines and the side chain diamine Liquid crystal aligning agent which is a mixture of both:

Wherein L ¹ is hydrogen, alkyl having 1 to 4 carbon atoms, phenyl or benzyl; X ¹ is a linear alkylene having 2 to 12 carbon atoms; X ² is a linear alkylene having 1 to 12 carbon atoms. Yes; X ³ , X ⁴ and X ⁵ are independently a single bond, —O—, —CO—, —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. Wherein t is an integer from 1 to 12, and X ⁴ in formula (VI) and X ⁵ in formula (VII) may be the same or different; any hydrogen on the cyclohexane ring or benzene ring is fluorine _{, -CH 3, -OH, -COOH,} -SO 3 H, -PO 3 H 2, benzyl Or may be replaced by hydroxybenzyl.

  According to the present invention, it is possible to provide a liquid crystal display element that has a high voltage holding ratio and a low ion density, and has reduced residual DC (that is unlikely to cause image sticking).

First, terms used in the present invention will be described.
“Liquid crystal aligning agent” means a composition used for forming a liquid crystal aligning film. The compound represented by formula (a) may be referred to as compound (a). The same applies to compounds represented by other formulas. Other diamine means diamines other than compound (a). Regarding the side chain type diamine and the non-side chain type diamine, definitions of these terms will be described at the beginning of the explanation on the other diamines used in the present invention. 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 any A is replaced by B, any A is replaced by C, and any A is D In addition to the case where it is replaced with, it is meant to include the case where a plurality of A are replaced with at least two of B to D. However, in the case where any —CH ₂ — may be replaced by —O—, the replacement of a plurality of consecutive —CH ₂ — with —O— is not included. A substituent that is not clearly bonded to the atoms constituting the ring is a substituent whose bonding position can be freely determined within a chemically acceptable range. A letter, for example, a symbol in which A is surrounded by a hexagon means ring A.

（ここに、Ｒ^１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^２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３〜３０のアルキルもしくは炭素数３〜３０のアルコキシを有するフェニル、または式（Ｄ−１）で表される基であって、これらのアルキルおよびアルコキシにおける任意の−ＣＨ_２−は−Ｏ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよく；

ここに、Ｒ^１３、Ｒ^１４およびＲ^１５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^１６およびＲ^１７は独立してフッ素またはメチルであって、ｍ１およびｍ２は独立して０、１または２であり；ｅ、ｆおよびｇは独立して０〜３の整数であって、これらの合計は１以上であり；Ｒ^１８は炭素数３〜３０のアルキル、炭素数３〜３０のアルコキシ、または炭素数３〜３０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く、そして任意の−ＣＨ_２−はジフルオロメチレンまたは式（Ｄ−２）で表される基で置き換えられてもよく；

ここに、Ｒ^１９、Ｒ^２０、Ｒ^２１およびＲ^２２は、独立して炭素数１〜１０のアルキルまたはフェニルであり、そしてｎは１〜１００の整数である。）

（ここに、Ｒ^３は独立して水素またはメチルであり；Ｒ^４は水素、炭素数１〜３０のアルキル、または炭素数２〜３０のアルケニルであり；そして、Ｒ^５は独立して単結合、−ＣＯ−または−ＣＨ_２−である。）

（ここに、Ｒ^３は独立して水素またはメチルであり；Ｒ^４は水素、炭素数１〜３０のアルキル、または炭素数２〜３０のアルケニルであり；Ｒ^５は独立して単結合、−ＣＯ−または−ＣＨ_２−であり；そして、Ｒ^６およびＲ^７は独立して水素、炭素数１〜３０のアルキル、またはフェニルである。）

（ここに、Ｒ^８は炭素数３〜３０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^９は独立して−Ｏ−または炭素数１〜６のアルキレンであり；環Ａは１，４−フェニレンまたは１，４−シクロヘキシレンであり；ａは０または１であり；ｂは０、１または２であり；そして、ｃは独立して０または１である。）

（ここに、Ｒ^１０は炭素数３〜３０のアルキルまたは炭素数３〜３０のフッ素化アルキルであり；Ｒ^１１は水素、炭素数１〜３０のアルキルまたは炭素数１〜３０のフッ素化アルキルであり；Ｒ^１２は独立して−Ｏ−または炭素数１〜６のアルキレンであり；そして、ｄは独立して０または１である。） The present invention comprises the above item [1] and the following items [2] to [24].
[2] The liquid crystal aligning agent according to item [1], wherein the side chain diamine is a diamine selected from the group of compounds represented by formulas (VIII) to (XII).

(Here, ^{R 1} is a single bond, -O -, - CO -, - COO -, - OCO -, - CONH -, - CH 2 O -, - CF 2 O-, or an alkylene having 1 to 6 carbon atoms And any —CH ₂ — in the alkylene may be replaced by —O—, —CH═CH— or —C≡C—; R ² is a group having a steroid skeleton, having 3 to 30 carbon atoms Alkyl having 3 to 30 carbon atoms or phenyl having 3 to 30 carbon atoms as a substituent, or a group represented by formula (D-1), and any- CH ₂ — may be replaced by —O—, —CH═CH— or —C≡C—;

Here, R ¹³ , R ¹⁴ and R ¹⁵ are each independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or ring C and C are independently 1,4-phenylene or 1,4-cyclohexylene; R ¹⁶ and R ¹⁷ are independently fluorine or methyl; M1 and m2 are independently 0, 1 or 2; e, f and g are each independently an integer of 0 to 3, and their sum is 1 or more; R ¹⁸ is carbon number An alkyl having 3 to 30 carbons, an alkoxy having 3 to 30 carbons, or an alkoxyalkyl having 3 to 30 carbons, and in these alkyls, alkoxys and alkoxyalkyls, any hydrogen is replaced by fluorine. And any —CH ₂ — may be replaced by difluoromethylene or a group represented by formula (D-2);

Here, R ¹⁹ , R ²⁰ , R ²¹ and R ²² are independently alkyl having 1 to 10 carbons or phenyl, and n is an integer of 1 to 100. )

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; and R ⁵ is independently a single bond. , -CO- or -CH ₂ - is).

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; R ⁵ is independently a single bond, — CO— or —CH ₂ —; and R ⁶ and R ⁷ are independently hydrogen, alkyl having 1 to 30 carbons, or phenyl.)

(Wherein R ⁸ is alkyl having 3 to 30 carbon atoms, and any —CH ₂ — in the alkyl may be replaced by —O—, —CH═CH— or —C≡C—; R ⁹ is independently —O— or alkylene having 1 to 6 carbons; Ring A is 1,4-phenylene or 1,4-cyclohexylene; a is 0 or 1; b is 0; 1 or 2; and c is independently 0 or 1.)

(Where R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms; R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms or fluorinated alkyl having 1 to 30 carbon atoms. Yes; R ¹² is independently —O— or alkylene having 1 to 6 carbons; and d is independently 0 or 1.

（ここに、Ｒ^２３、Ｒ^２４、Ｒ^２９およびＲ^３０は、独立して炭素数３〜３０のアルキル、または炭素数３〜３０のアルコキシである。） [3] The non-side chain diamine is represented by formula (IV-1), formula (IV-2), formula (IV-15), formula (IV-16), formula (V-1) to formula (V-12). , A diamine selected from the compounds represented by formula (V-33) and formula (VII-2), and the side chain diamine is formula (VIII-2), formula (VIII-4), formula (VIII-5) ), A liquid crystal aligning agent according to item [1], which is a diamine selected from compounds represented by formula (VIII-6), formula (XI-2) and formula (XI-4).

(Here, R ²³ , R ²⁴ , R ²⁹ and R ³⁰ are each independently alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms.)

[4] The tetracarboxylic dianhydride is represented by formula (1), formula (2), formula (5) to formula (9), formula (14), formula (19), formula (23), formula (25), Any one of [1] to [3], which is at least one selected from the compounds represented by formula (35) to formula (37), formula (39), formula (44) and formula (49) A liquid crystal aligning agent according to item.

[5] At least one tetracarboxylic dianhydride is selected from compounds represented by formula (1), formula (6) to formula (9), formula (19), formula (23) and formula (25). The liquid crystal aligning agent of any one of [1]-[3] which is one.

[6] Any one of [1] to [3], wherein the tetracarboxylic dianhydride is at least one selected from the compounds represented by formula (1), formula (19), and formula (23). A liquid crystal aligning agent according to item.

[7] Based on the total amount of diamine, the content of diamine represented by formula (a) is 1 to 50 mol%, and the content of other diamines is 50 to 99 mol%. [6] The liquid crystal aligning agent according to any one of [6].

[8] At least one polymer selected from the group consisting of a polyamic acid obtained by reacting a mixture of a diamine represented by formula (a) and a non-side chain diamine with tetracarboxylic dianhydride and a derivative thereof. And at least one polymer selected from the group consisting of polyamic acid obtained by reacting a mixture of a diamine represented by formula (a) and a side chain diamine with tetracarboxylic dianhydride and a derivative thereof The liquid crystal aligning agent as described in item [1].

（ここに、Ｒ^２３、Ｒ^２４、Ｒ^２９およびＲ^３０は、独立して炭素数３〜３０のアルキル、または炭素数３〜３０のアルコキシである。） [9] The non-side chain diamine is represented by formula (IV-1), formula (IV-2), formula (IV-15), formula (IV-16), formula (V-1) to formula (V-12). , A diamine selected from the compounds represented by formula (V-33) and formula (VII-2), and the side chain diamine is formula (VIII-2), formula (VIII-4), formula (VIII-5) ), A liquid crystal aligning agent according to item [8], which is a diamine selected from compounds represented by formula (VIII-6), formula (XI-2) and formula (XI-4).

(Here, R ²³ , R ²⁴ , R ²⁹ and R ³⁰ are each independently alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms.)

[10] At least one tetracarboxylic dianhydride is selected from the compounds represented by formula (1), formula (6) to formula (9), formula (19), formula (23) and formula (25). The liquid crystal aligning agent as described in the item [8] or [9].

[11] It further contains at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a diamine other than the diamine represented by formula (a) with tetracarboxylic dianhydride and a derivative thereof, [ The liquid crystal aligning agent according to any one of [1] to [6] and [8] to [10].

ここに、Ｘ^１は炭素数２〜１２の直鎖アルキレンであり；Ｘ^２は炭素数１〜１２の直鎖アルキレンであり；Ｘ^３、Ｘ^４およびＸ^５は独立して単結合、−Ｏ−、−ＣＯ−、−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、そして式（VI）におけるＸ^４および式（VII）におけるＸ^５はそれぞれ同一でも異なってもよく；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、−ＣＨ_３、−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。 [12] At least one diamine other than the diamine represented by the formula (a) selected from the group of non-side chain diamines represented by the formula (I) to the formula (VII), an alkyl having 3 or more carbon atoms, A terminal ring of alkoxy having 3 or more carbon atoms, alkoxyalkyl having 3 or more carbon atoms, a group having a steroid skeleton, and alkyl having 3 or more carbon atoms, alkoxy having 3 or more carbon atoms or alkoxyalkyl having 3 or more carbon atoms as a substituent Item [11], which is at least one side chain diamine having a side chain group selected from ring-containing groups in the above, or a mixture of at least one non-side chain diamine and side chain diamine. Liquid crystal aligning agent:

Wherein X ¹ is a linear alkylene having 2 to 12 carbon atoms; X ² is a linear alkylene having 1 to 12 carbon atoms; X ³ , X ⁴ and X ⁵ are independently a single bond, —O -, - CO -, - 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, and in the formula (VI) X ⁴ and X ⁵ in formula (VII) may be the same or different; any hydrogen of the cyclohexane ring or the benzene ring is fluorine, —CH ₃ , —OH, —COOH, —SO ₃ H, —PO ₃ H _2, may be replaced by benzyl or hydroxybenzyl.

（ここに、Ｒ^１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^２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３〜３０のアルキルもしくは炭素数３〜３０のアルコキシを有するフェニル、または式（Ｄ−１）で表される基であって、これらのアルキルおよびアルコキシにおける任意の−ＣＨ_２−は−Ｏ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよく；

ここに、Ｒ^１３、Ｒ^１４およびＲ^１５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^１６およびＲ^１７は独立してフッ素またはメチルであって、ｍ１およびｍ２は独立して０、１または２であり；ｅ、ｆおよびｇは独立して０〜３の整数であって、これらの合計は１以上であり；Ｒ^１８は炭素数３〜３０のアルキル、炭素数３〜３０のアルコキシ、または炭素数３〜３０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く、そして任意の−ＣＨ_２−はジフルオロメチレンまたは式（Ｄ−２）で表される基で置き換えられてもよく；

ここに、Ｒ^１９、Ｒ^２０、Ｒ^２１およびＲ^２２は、独立して炭素数１〜１０のアルキルまたはフェニルであり、そしてｎは１〜１００の整数である。）

（ここに、Ｒ^３は独立して水素またはメチルであり；Ｒ^４は水素、炭素数１〜３０のアルキル、または炭素数２〜３０のアルケニルであり；そして、Ｒ^５は独立して単結合、−ＣＯ−または−ＣＨ_２−である。）

（ここに、Ｒ^３は独立して水素またはメチルであり；Ｒ^４は水素、炭素数１〜３０のアルキル、または炭素数２〜３０のアルケニルであり；Ｒ^５は独立して単結合、−ＣＯ−または−ＣＨ_２−であり；そして、Ｒ^６およびＲ^７は独立して水素、炭素数１〜３０のアルキル、またはフェニルである。）

（ここに、Ｒ^８は炭素数３〜３０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^９は独立して−Ｏ−または炭素数１〜６のアルキレンであり；環Ａは１，４−フェニレンまたは１，４−シクロヘキシレンであり；ａは０または１であり；ｂは０、１または２であり；そして、ｃは独立して０または１である。）

（ここに、Ｒ^１０は炭素数３〜３０のアルキルまたは炭素数３〜３０のフッ素化アルキルであり；Ｒ^１１は水素、炭素数１〜３０のアルキルまたは炭素数１〜３０のフッ素化アルキルであり；Ｒ^１２は独立して−Ｏ−または炭素数１〜６のアルキレンであり；そして、ｄは独立して０または１である。） [13] The liquid crystal aligning agent according to item [12], wherein the side chain diamine is a diamine selected from the group of compounds represented by formulas (VIII) to (XII).

(Here, ^{R 1} is a single bond, -O -, - CO -, - COO -, - OCO -, - CONH -, - CH 2 O -, - CF 2 O-, or an alkylene having 1 to 6 carbon atoms And any —CH ₂ — in the alkylene may be replaced by —O—, —CH═CH— or —C≡C—; R ² is a group having a steroid skeleton, having 3 to 30 carbon atoms Alkyl having 3 to 30 carbon atoms or phenyl having 3 to 30 carbon atoms as a substituent, or a group represented by formula (D-1), and any- CH ₂ — may be replaced by —O—, —CH═CH— or —C≡C—;

Here, R ¹³ , R ¹⁴ and R ¹⁵ are each independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or ring C and C are independently 1,4-phenylene or 1,4-cyclohexylene; R ¹⁶ and R ¹⁷ are independently fluorine or methyl; M1 and m2 are independently 0, 1 or 2; e, f and g are each independently an integer of 0 to 3, and their sum is 1 or more; R ¹⁸ is carbon number An alkyl having 3 to 30 carbons, an alkoxy having 3 to 30 carbons, or an alkoxyalkyl having 3 to 30 carbons, and in these alkyls, alkoxys and alkoxyalkyls, any hydrogen is replaced by fluorine. And any —CH ₂ — may be replaced by difluoromethylene or a group represented by formula (D-2);

Here, R ¹⁹ , R ²⁰ , R ²¹ and R ²² are independently alkyl having 1 to 10 carbons or phenyl, and n is an integer of 1 to 100. )

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; and R ⁵ is independently a single bond. , -CO- or -CH ₂ - is).

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; R ⁵ is independently a single bond, — CO— or —CH ₂ —; and R ⁶ and R ⁷ are independently hydrogen, alkyl having 1 to 30 carbons, or phenyl.)

(Wherein R ⁸ is alkyl having 3 to 30 carbon atoms, and any —CH ₂ — in the alkyl may be replaced by —O—, —CH═CH— or —C≡C—; R ⁹ is independently —O— or alkylene having 1 to 6 carbons; Ring A is 1,4-phenylene or 1,4-cyclohexylene; a is 0 or 1; b is 0; 1 or 2; and c is independently 0 or 1.)

(Where R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms; R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms or fluorinated alkyl having 1 to 30 carbon atoms. Yes; R ¹² is independently —O— or alkylene having 1 to 6 carbons; and d is independently 0 or 1.

（ここに、Ｒ^２３、Ｒ^２４、Ｒ^２９およびＲ^３０は、独立して炭素数３〜３０のアルキル、または炭素数３〜３０のアルコキシである。） [14] The non-side chain diamine is represented by formula (IV-1), formula (IV-2), formula (IV-15), formula (IV-16), formula (V-1) to formula (V-12). , A diamine selected from the compounds represented by formula (V-33) and formula (VII-2), and the side chain diamine is formula (VIII-2), formula (VIII-4), formula (VIII-5) ), A liquid crystal aligning agent according to item [12], which is a diamine selected from compounds represented by formula (VIII-6), formula (XI-2) and formula (XI-4).

(Here, R ²³ , R ²⁴ , R ²⁹ and R ³⁰ are each independently alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms.)

[15] The tetracarboxylic dianhydride is represented by formula (1), formula (2), formula (5) to formula (9), formula (14), formula (19), formula (23), formula (25), Any one of [12] to [14], which is at least one selected from the compounds represented by formula (35) to formula (37), formula (39), formula (44) and formula (49) A liquid crystal aligning agent according to item.

[16] At least one tetracarboxylic dianhydride is selected from compounds represented by formula (1), formula (6) to formula (9), formula (19), formula (23) and formula (25). The liquid crystal aligning agent of any one of [12]-[14] which is one.

[17] Any one of [12] to [14], wherein the tetracarboxylic dianhydride is at least one selected from the compounds represented by formula (1), formula (19), and formula (23). A liquid crystal aligning agent according to item.

[18] The liquid crystal aligning agent according to any one of [1] to [6], further comprising a compound having at least two oxiranyl groups.

[19] The liquid crystal aligning agent according to any one of [8] to [10], further containing a compound having at least two oxiranyl groups.

[20] The liquid crystal aligning agent according to any one of [11] to [17], further comprising a compound having at least two oxiranyl groups.

（ここに、ｎは０〜１０の整数である。） [21] The any one of [18] to [20], wherein the compound having at least two oxiranyl groups is at least one selected from the compounds represented by formulas (E1) to (E5). Liquid crystal aligning agent.

(Here, n is an integer from 0 to 10.)

[22] The ratio of the compound having at least two oxiranyl groups is 0.001 to 0.40 in a weight ratio with respect to the total amount of at least one polymer selected from the group consisting of polyamic acid and derivatives thereof. [21] The liquid crystal aligning agent according to any one of [21].

[23] A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of [1] to [22].

[24] The liquid crystal according to item [23], having a pair of substrates, a liquid crystal layer sandwiched between the substrates, and an electrode for applying a voltage to the liquid crystal layer, and a surface of the substrate in contact with the liquid crystal layer A liquid crystal display element on which an alignment film is formed.

式（ａ）において、Ｌ^１は水素、炭素数１〜４のアルキル、フェニルまたはベンジルであり、好ましくは水素または炭素数１〜４のアルキルである。そして、特に好ましいＬ^１は水素およびメチルである。本発明では、このような化合物（ａ）の２つ以上を用いてもよい。 The liquid crystal aligning agent of the present invention is at least selected from the group consisting of a polyamic acid obtained by reacting a mixture of a diamine represented by formula (a) and another diamine with tetracarboxylic dianhydride and a derivative thereof. A composition containing one polymer.

In the formula (a), L ¹ is hydrogen, alkyl having 1 to 4 carbons, phenyl or benzyl, preferably hydrogen or alkyl having 1 to 4 carbons. Particularly preferred L ¹ is hydrogen and methyl. In the present invention, two or more of such compounds (a) may be used.

  Examples of polyamic acid derivatives are soluble polyimides, polyamic acid esters, and polyamic acid amides. More specifically, a polyimide obtained by completely dehydrating and cyclizing an amide bond and a carboxyl group of a polyamic acid, a partial polyimide obtained by partially dehydrating and cyclizing a polyamic acid, a polyamic acid ester obtained by converting a carboxyl group of a polyamic acid into an ester, tetra A polyamic acid-polyamide copolymer obtained by reacting a part of a carboxylic dianhydride with a dicarboxylic acid (or its halide or anhydride), and the polyamic acid-polyamide copolymer partially or completely. And polyamideimide obtained by dehydration ring closure. In addition, when tetracarboxylic dianhydride and dicarboxylic acid are mixed and used as an acid component, not only a polyamic acid-polyamide copolymer but also a mixture containing polyamide and / or polyamic acid may be obtained. However, in the present invention, it is referred to as a polyamic acid-polyamide copolymer based on such a possibility. The liquid crystal aligning agent of this invention contains the at least 1 polymer chosen from such polyamic acid and its derivative (s). In the present invention, polyamic acid and polyimide are particularly preferable among polyamic acid and derivatives thereof. Since polyimide is a polymer obtained by dehydrating and ring-closing polyamic acid, a mixture of polyamic acid and partially imidized polyamic acid may be obtained depending on the heating conditions in the synthesis process of polyamic acid. .

  By the way, diamine can be divided into two types depending on the difference in 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 or polyimide having a large number of side chain groups with respect to the main chain of the polymer is obtained. When a polyamic acid or polyimide 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 aligning agent containing this polymer increases the pretilt angle in the liquid crystal display element. Can do. That is, this side chain group is a group having an effect of increasing the pretilt angle. Examples of the side chain group having such an effect are 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. A group having one or more rings, wherein the terminal ring has any one of alkyl having 3 or more carbon atoms, alkoxy having 3 or more carbon atoms and alkoxyalkyl having 3 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 present invention, a diamine having such a side chain group is referred to as a side chain diamine. Such a diamine having no side chain group is referred to as a non-side chain diamine. In addition, both a side chain type diamine and a non-side chain type diamine are defined as the kind of diamine which does not contain a compound (a).

  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, on condition that the terminal ring has alkyl having 3 or more carbon atoms, alkoxy having 3 or more carbon atoms or alkoxyalkyl having 3 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 an alkyl having 3 or more carbon atoms as a substituent, a fluorine-substituted alkyl having 3 or more carbon atoms, carbon A ring assembly group having an alkoxy having several or more carbon atoms or an alkoxyalkyl having three or more carbon atoms can be given. Of course, a group having a steroid skeleton is also effective as a side chain group.

  In the present invention, the compound (a) and other diamine are used in combination, and the other diamine is at least one non-side chain diamine, at least one side chain diamine, or non-side chain diamine. It is a mixture of at least one and at least one side chain diamine. The non-side chain diamine used in the present invention is a diamine represented by the formula (I) to the formula (VII).

これらの式における記号の意味は前記の通りである。

The meanings of the symbols in these formulas are as described above.

Preferred examples of the diamine represented by the formula (I) are shown below.

Preferred examples of the diamine represented by the formula (II) are shown below.

Preferred examples of the diamine represented by the formula (III) are shown below.

Preferred examples of the diamine represented by the formula (IV) are shown below.

Preferred examples of the diamine represented by the formula (V) are shown below.

Preferred examples of the diamine represented by the formula (VI) are shown below.

Preferred examples of the diamine represented by the formula (VII) are shown below.

  Among these diamines, more preferred examples include compound (IV-1) to compound (IV-5), compound (IV-15), compound (IV-16), compound (V-1) to compound (V- 12), Compound (V-26), Compound (V-27), Compound (V-31), Compound (V-33), Compound (VI-1), Compound (VI-2), Compound (VI-6) ), And compound (VII-1) to compound (VII-5), and particularly preferred examples are compound (IV-1), compound (IV-2), compound (IV-15), and compound (IV-16). Compound (V-1) to Compound (V-12), Compound (V-33), and Compound (VII-2).

Specific examples of the side chain diamine used in the present invention include diamines represented by the following formulas (VIII) to (XII).

Wherein (VIII), ^{R 1} 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—. R ² is a group having a steroid skeleton, alkyl having 3 to 30 carbons, phenyl having 3 to 30 alkyls or alkoxy having 3 to 30 carbons as a substituent, or represented by formula (D-1) It is a group. Then, any -CH ₂ - in the alkyl and alkoxy - is -O -, - may be replaced by CH = CH- or -C≡C-.

ここに、Ｒ^１３、Ｒ^１４およびＲ^１５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^１６およびＲ^１７は独立してフッ素またはメチルであって、ｍ１およびｍ２は独立して０、１または２であり；ｅ、ｆおよびｇは独立して０〜３の整数であって、これらの合計は１以上であり；Ｒ^１８は炭素数３〜３０のアルキル、炭素数３〜３０のアルコキシ、または炭素数３〜３０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く、そして任意の−ＣＨ_２−はジフルオロメチレンまたは式（Ｄ−２）で表される基で置き換えられてもよい。

Here, R ¹³ , R ¹⁴ and R ¹⁵ are each independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or ring C and C are independently 1,4-phenylene or 1,4-cyclohexylene; R ¹⁶ and R ¹⁷ are independently fluorine or methyl; M1 and m2 are independently 0, 1 or 2; e, f and g are each independently an integer of 0 to 3, and their sum is 1 or more; R ¹⁸ is carbon number An alkyl having 3 to 30 carbons, an alkoxy having 3 to 30 carbons, or an alkoxyalkyl having 3 to 30 carbons, and in these alkyls, alkoxys and alkoxyalkyls, any hydrogen is replaced by fluorine. And any —CH ₂ — may be replaced by difluoromethylene or a group represented by the formula (D-2).

ここに、Ｒ^１９、Ｒ^２０、Ｒ^２１およびＲ^２２は、独立して炭素数１〜１０のアルキルまたはフェニルであり、そしてｎは１〜１００の整数である。

Here, R ¹⁹ , R ²⁰ , R ²¹ and R ²² are independently alkyl having 1 to 10 carbons or phenyl, and n is an integer of 1 to 100.

ここに、Ｒ^３は独立して水素またはメチルであり；Ｒ^４は水素、炭素数１〜３０のアルキル、または炭素数２〜３０のアルケニルであり；そして、Ｒ^５は独立して単結合、−ＣＯ−または−ＣＨ_２−である。２つのアミノフェニル−Ｒ^５−Ｏ−基の一方はステロイド骨格の３位に結合し、もう一方は６位に結合していることが好ましい。また、２つのアミノ基のベンゼン環への結合位置はそれぞれ、Ｒ^５の結合位置に対してメタ位またはパラ位であることが好ましい。なお、ステロイド骨格を形成する炭素に結合している任意の水素はメチルで置き換えられてもよい。

Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; and R ⁵ is independently a single bond, —CO— or —CH ₂ —. One of the two aminophenyl-R ⁵ —O— groups is preferably bonded to the 3-position of the steroid skeleton and the other is bonded to the 6-position. Moreover, it is preferable that the bonding position of the two amino groups to the benzene ring is meta or para with respect to the bonding position of R ⁵ . Note that any hydrogen bonded to carbon forming the steroid skeleton may be replaced with methyl.

ここに、Ｒ^３は独立して水素またはメチルであり；Ｒ^４は水素、炭素数１〜３０のアルキル、または炭素数２〜３０のアルケニルであり；Ｒ^５は独立して単結合、−ＣＯ−または−ＣＨ_２−であり；そして、Ｒ^６およびＲ^７は独立して水素、炭素数１〜３０のアルキル、またはフェニルである。２つのＲ^７置換アミノフェニル−Ｒ^５−Ｏ−基のベンゼン環への結合位置はそれぞれ、ステロイド骨格が結合している炭素に対してメタ位またはパラ位であることが好ましい。また、２つのアミノ基のベンゼン環への結合位置はそれぞれ、Ｒ^５に対してメタ位またはパラ位であることが好ましい。

Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; R ⁵ is independently a single bond, —CO — Or —CH ₂ —; and R ⁶ and R ⁷ are independently hydrogen, alkyl having 1 to 30 carbons, or phenyl. The bonding positions of the two R ⁷ -substituted aminophenyl-R ⁵ —O— groups to the benzene ring are each preferably in the meta position or the para position with respect to the carbon to which the steroid skeleton is bonded. Moreover, it is preferable that the bonding position of the two amino groups to the benzene ring is meta or para with respect to R ⁵ .

ここに、Ｒ^８は炭素数３〜３０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^９は独立して−Ｏ−または炭素数１〜６のアルキレンであり；環Ａは１，４−フェニレンまたは１，４−シクロヘキシレンであり；ａは０または１であり；ｂは０、１または２であり；そして、ｃは独立して０または１である。２つのアミノ基のベンゼン環への結合位置は、それぞれＲ⁹に対してメタ位またはパラ位であることが好ましい。

Here, R ⁸ is alkyl having 3 to 30 carbons, and any —CH ₂ — in the alkyl may be replaced by —O—, —CH═CH— or —C≡C—; R ⁹ is independently -O- or alkylene having 1 to 6 carbon atoms; ring A is 1,4-phenylene or 1,4-cyclohexylene; a is 0 or 1; b is 0, 1 Or c; and c is independently 0 or 1. The bonding position of the two amino groups to the benzene ring is preferably meta or para to R ⁹ , respectively.

ここに、Ｒ^１０は炭素数３〜３０のアルキルまたは炭素数３〜３０のフッ素化アルキルであり；Ｒ^１１は水素、炭素数１〜３０のアルキルまたは炭素数１〜３０のフッ素化アルキルであり；Ｒ^１２は独立して−Ｏ−または炭素数１〜６のアルキレンであり；そして、ｄは独立して０または１である。２つのアミノ基のベンゼン環への結合位置は、それぞれＲ^１２に対してメタ位またはパラ位であることが好ましい。

Wherein R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms; R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms or fluorinated alkyl having 1 to 30 carbon atoms. R ¹² is independently —O— or alkylene having 1 to 6 carbons; and d is independently 0 or 1. The bonding position of the two amino groups to the benzene ring is preferably meta or para to R ¹² , respectively.

Examples of the diamine represented by the formula (VIII) include diamines represented by the formula (VIII-1) to the formula (VIII-43).

In the formulas (VIII-1) to (VIII-11), R ²³ and R ²⁴ are each preferably alkyl having 3 to 30 carbons or alkoxy having 3 to 30 carbons, and having 5 to 25 carbons. More preferably, it is alkyl or alkoxy having 5 to 25 carbon atoms.

In Formula (VIII-12) to Formula (VIII-15), R ²⁵ is preferably alkyl having 4 to 30 carbons, and more preferably alkyl having 6 to 25 carbons. In the formulas (VIII-16) and (VIII-17), R ²⁶ is preferably alkyl having 6 to 30 carbons, and more preferably alkyl having 8 to 25 carbons.

In formulas (VIII-18) to (VIII-37), R ²⁷ and R ²⁸ are each preferably alkyl having 3 to 30 carbons or alkoxy having 3 to 30 carbons, and having 5 to 25 carbons. It is more preferable that they are alkyl or alkoxy having 5 to 25 carbon atoms.

  Of these, diamines represented by the formulas (VIII-1) to (VIII-11) are preferable, and the formulas (VIII-2), (VIII-4), (VIII-5) and (VIII-) are preferred. The diamine represented by any one of 6) is more preferable.

Examples of the diamine represented by the formula (IX) include diamines represented by the formula (IX-1) to the formula (IX-4).

Examples of the diamine represented by the formula (X) include diamines represented by the formula (X-1) to the formula (X-8).

Examples of the diamine represented by the formula (XI) include diamines represented by the formula (XI-1) to the formula (XI-8).

In Formula (XI-1) to Formula (XI-3), R ²⁹ is preferably alkyl having 3 to 30 carbon atoms. In Formula (XI-4) to Formula (XI-8), R ³⁰ is carbon. It is preferable that it is a C3-C20 alkyl. And among a compound (XI-1)-a compound (XI-8), a compound (XI-2) and a compound (XI-4) are preferable.

これらの式において、Ｒ^３１は炭素数６〜２０のアルキルであることが好ましく、Ｒ^３２は水素、または炭素数１〜１０のアルキルであることが好ましい。 Examples of the diamine represented by the formula (XII) include diamines represented by the formula (XII-1) to the formula (XII-3).

In these formulas, R ³¹ is preferably alkyl having 6 to 20 carbon atoms, and R ³² is preferably hydrogen or alkyl having 1 to 10 carbon atoms.

  Among the above side chain diamines, compound (VIII-2), compound (VIII-4), compound (VIII-5), compound (VIII-6), compound (XI-2) and compound (XI-4) Is preferred. In the present invention, a diamine other than the compound (a) and the compounds (I) to (XII) may be used in combination. Examples of such diamines include naphthalene diamines having a naphthalene structure, fluorene diamines having a fluorene structure, and siloxane diamines having a siloxane bond, and these diamines have side chain groups. May be.

式（XV）において、Ｒ^３３およびＲ^３４はそれぞれ独立して炭素数１〜３のアルキルまたはフェニルであり、Ｘ^４は独立して炭素数１〜６のアルキレン、またはフェニレンであり、ｍは１〜１０の整数である。なお、このフェニレンの任意の水素は炭素数１〜４のアルキルで置き換えられてもよい。 A preferred example of the siloxane-based diamine is a compound represented by the following formula (XV).

In the formula (XV), R ³³ and R ³⁴ are each independently alkyl or phenyl having 1 to 3 carbon atoms, X ⁴ is independently alkylene having 1 to 6 carbon atoms or phenylene, and m is 1 It is an integer of -10. In addition, arbitrary hydrogen of this phenylene may be replaced by C1-C4 alkyl.

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のアルキルである。 Preferred examples of the diamine other than the compound (a) and the compounds (I) to (XII) include compounds represented by the following formulas (1 ′) to (8 ′) in addition to the siloxane-based diamine. Can be mentioned.

In these formulas, R ³⁵ and R ³⁶ are each independently alkyl having 3 to 30 carbon atoms.

  In the present invention, a monoamine may be used in addition to the diamine. By so doing, termination of the polymerization reaction can be caused, and further progress of the reaction can be suppressed, so that the molecular weight of the resulting polymer (polyamic acid) can be easily controlled. The ratio of the monoamine to the diamine may be in a range that does not impair the effects of the present invention, but as a guideline, it is preferably 10 mol% or less of the total amine amount.

  In the production of the polymer in the present invention, the compound (a) is used by mixing with other diamine. At this time, the content of the compound (a) in the total amount of diamine is preferably 1 mol% or more from the viewpoint of improving the voltage holding ratio, reducing the ion density and residual DC in the liquid crystal display device. If the content rate of a compound (a) is 1 mol% or more, it can prevent that the improvement effect with respect to these electrical characteristics fades, or the effect with respect to an afterimage is not seen.

  It is preferable to mix and use at least one of the compound (a) and the non-side chain diamine from the viewpoint of improving black display characteristics when no voltage is applied in a horizontal electric field type liquid crystal display element. Further, the use of these diamines is very effective for the transverse electric field system because it brings a low pretilt angle to the liquid crystal display element. Although the liquid crystal orientation improves as the content of the non-side chain diamine in the total amount of diamine increases, the content is preferably in the range of 1 to 50 mol% in consideration of the reduction of residual DC.

  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 a mixture of at least one side chain diamine and compound (a). By controlling the type and ratio of these diamines, a predetermined pretilt angle can be expressed, but considering the reduction of residual DC, the content of side chain diamines is in the range of 1 to 50 mol%. Is preferred. By using the side chain type diamine in combination, the liquid crystal display element to which the obtained polymer is applied can be a vertical electric field type liquid crystal display element having a further improved voltage holding ratio.

  Moreover, when it contains further diamine other than said compound (a) and compound (I)-compound (XII), it is obtained that the content rate of this diamine is 30 mol% or less of the total amount of diamine. In the liquid crystal display element to which is applied, it is preferable from the viewpoint of sufficiently exhibiting the voltage holding ratio improvement, the reduction of ion density and residual DC, the improvement effect of contrast, and the like.

Next, the tetracarboxylic dianhydride used in the present invention will be described.
The tetracarboxylic dianhydride can be selected on the condition that the polyamic acid obtained using the tetracarboxylic dianhydride is soluble in the solvent used for the liquid crystal aligning agent. Such tetracarboxylic dianhydrides are exemplified separately from aromatic tetracarboxylic dianhydrides and the others. First, the preferable example of aromatic tetracarboxylic dianhydride is shown next.

Preferred examples of non-aromatic tetracarboxylic dianhydrides are shown below.

  Of the above tetracarboxylic dianhydrides, compound (1), compound (6), compound (9), compound (19), compound (23) and compound (25) are more preferred, and compound (1) and compound (19) and compound (23) are particularly preferred.

  In the present invention, a part of the tetracarboxylic dianhydride may be replaced with a carboxylic anhydride. Replacing a part of tetracarboxylic dianhydride with carboxylic acid anhydride can cause polymerization reaction termination, and further progress of the reaction can be suppressed, so the molecular weight of the resulting polyamic acid is easy Can be controlled. The ratio of the carboxylic acid anhydride to the tetracarboxylic dianhydride may be in a range that does not impair the effects of the present invention, but it is preferably set to 10 mol% or less of the total tetracarboxylic dianhydride amount.

  As described above, the aligning agent of the present invention is selected from the group consisting of polyamic acid obtained by reacting a mixture of compound (a) and non-side chain diamine with tetracarboxylic dianhydride and derivatives thereof. At least one polymer, at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a mixture of a compound (a) and a side chain diamine and tetracarboxylic dianhydride and a derivative thereof (a 3) of at least one polymer selected from the group consisting of polyamic acid obtained by reacting a mixture of non-side-chain diamine and side-chain diamine with tetracarboxylic dianhydride and derivatives thereof It is a composition containing at least one kind. In the following description excluding the examples, “polyamic acid” is used as a generic term for polyamic acid and its derivatives.

  That is, it may be an aligning agent containing only one of these three kinds of polymers, or an aligning agent containing two kinds. As an alignment agent containing two kinds of polymers, a polyamic acid obtained by using a mixture of a polyamic acid obtained by using a mixture of a compound (a) and a non-side chain diamine, a compound (a) and a side chain diamine, and the like. Those containing an acid are preferred.

  The liquid crystal aligning agent of this invention can further contain at least 1 of the polyamic acid obtained without using a compound (a). It is preferable to make each selection range of diamine other than the compound (a) used at this time and tetracarboxylic dianhydride the same as said case using a compound (a).

  When at least one polyamic acid obtained without using the compound (a) is added to form a polymer blend composition, the content thereof should be 1 to 50% by weight based on the total amount of the polymer in the liquid crystal aligning agent. From the viewpoint of achieving both the manifestation of the effect of the present invention and the adjustment of orientation. A more preferable range of this ratio is 2 to 30% by weight.

  In reacting the tetracarboxylic dianhydride with the diamine, the amount of tetracarboxylic dianhydride used should be approximately equimolar to the total number of diamines (molar ratio of about 0.9 to 1.1). Is preferred. And the molecular weight of a polyamic acid is a weight average molecular weight (Mw) of polystyrene conversion by gel permeation chromatography (GPC) method, for example, Preferably it is 10,000-500,000, More preferably, it is 20,000-200,000. It is.

  The polyamic acid in the present invention is identified by precipitating with a large amount of a poor solvent, separating the solid and the solvent completely by filtration or the like, and analyzing by IR or NMR. Furthermore, after the solid polyamic acid is decomposed 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 to identify the raw material compound used. can do.

  The liquid crystal aligning agent of this invention may further contain an epoxy compound from a viewpoint of improving the durability in a liquid crystal aligning film, for example as other components other than the said polyamic acid. The epoxy compound is preferably a compound having two or more oxiranyl groups. The following compounds (E1) to (E5) are preferable examples of such epoxy compounds.

（ここに、ｎは０〜１０の整数である。）

(Here, n is an integer from 0 to 10.)

  When using an epoxy compound, the preferable addition amount is 0.001-0.40 in the weight ratio with respect to the total amount of polyamic acid. At this time, in the liquid crystal alignment film formed from this liquid crystal aligning agent, it is possible to expect an effect of improving durability such as prevention of film abrasion due to rubbing treatment. And this more preferable addition ratio is 0.002-0.30 by the said weight ratio.

  Examples of epoxy compounds other than compound (E1) to compound (E5) include bisphenol A type epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, polymer of monomer having oxirane, monomer having oxirane and others And a copolymer with the monomer. Specific examples include “Epicoat 807”, “Epicoat 815”, “Epicoat 825”, and “Epicoat 827” of Japan Epoxy Resin Co., Ltd.

  Compound (E1) can be obtained as “Araldite CY184” of Ciba Geigy Japan. The compound (E2) can be obtained as “Celoxide 2021P” or “EHPE-3150” from Daicel Chemical Industries, Ltd. The compound (E3) is available as “Techmore VG3101L” from Mitsui Chemicals. Compound (E4) is “Epicoat 828”, “Epicoat 190P”, “Epicoat 191P”, “Epicoat 1004”, “Epicoat 1256” of Japan Epoxy Resin Co., Ltd. or “Araldite CY177” of Ciba Geigy Japan Co., Ltd. Available. Compound (E5) (4,4'-methylenebis (N, N-diglycidylaniline)) can be obtained from Sigma-Aldrich.

  Among these, “Epicoat 828”, “Araldite CY184”, “Celoxide 2021P”, “Techmore VG3101L”, and the compound (E5), which are a mixture of compounds where n = 0 to 4 in the formula (E4), are liquid crystal alignment. It is more preferable from the viewpoint of improving the transparency and flatness of the film.

  For example, the liquid crystal aligning agent of the present invention may further contain a silane coupling agent, a titanium-based coupling agent, and a coupling agent such as an aminosilicon compound from the viewpoint of improving adhesion to the substrate. Good. Such a coupling agent may be used alone, or two or more compounds may be mixed and used. When using a coupling agent, the preferable density | concentration in a liquid crystal aligning agent is 0.01 to 6 weight%.

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

  Examples of the epoxy compound include glycidyl ether, glycidyl ester, glycidyl amine, epoxy group-containing acrylic resin, glycidyl amide, glycidyl isocyanurate, a chain aliphatic epoxy compound, and a 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 glycidyl ether are bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol S type epoxy compound, bisphenol type epoxy compound, hydrogenated bisphenol-A type epoxy compound, hydrogenated bisphenol-F type epoxy compound, hydrogenated 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 novolac type epoxy compound, brominated phenol novolak type epoxy compound , Brominated cresol novolac type epoxy compound, bisphenol A novolac type epoxy compound, naphthalene skeleton-containing epoxy compound, aromatic polyglycy 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 glycidyl esters are diglycidyl ester compounds and glycidyl ester epoxy compounds. An example of a glycidylamine is a polyglycidylamine compound. Examples of the epoxy group-containing acrylic compound are homopolymers and copolymers of acrylic monomers having oxiranyl. An example of glycidyl amide is a glycidyl amide type epoxy compound.

  An example of the chain aliphatic epoxy compound is an epoxy group-containing compound obtained by oxidizing a carbon-carbon double bond of an alkene compound. An example of the cycloaliphatic epoxy compound is an epoxy group-containing compound obtained by oxidizing a carbon-carbon double bond of a cycloalkene compound.

  The liquid crystal aligning agent of this invention may further contain polymer components, such as polyester, an acrylic acid polymer, an acrylate polymer, and polyamide, in the range which does not impair the characteristic of this invention. A preferable addition ratio of these polymer components is 0.20 or less by weight ratio to the polyamic acid.

  The liquid crystal aligning agent of the invention may further contain a surfactant in accordance with the purpose from the viewpoint of improving the coating property of the liquid crystal aligning agent, or charged from the viewpoint of improving the antistatic property of the liquid crystal aligning agent. An inhibitor may be further contained.

  The liquid crystal aligning agent of the present invention may further contain a solvent from the viewpoint of the application property of the liquid crystal aligning agent and the adjustment of the concentration of the polyamic acid. This solvent can be used without any particular limitation as long as it has the ability to dissolve the polymer component. For example, it can be used from the solvents usually used in the production process and application of polymer components such as polyamic acid and soluble polyimide. Can be selected appropriately according to the conditions and are used alone or as a mixture of two or more solvents.

  Examples of such a solvent include a parent solvent for polyamic acid and other solvents for improving coating properties. Examples of the aprotic polar organic solvent that is a parent solvent for polyamic acid are N-methyl-2-pyrrolidone, dimethylimidazolidinone, N-methylcaprolactam, N-methylpropionamide, N, N-dimethylacetamide, dimethyl Lactones such as 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 such as dipropylene glycol monomethyl ether Examples include glycol monoalkyl ethers and ester compounds such as these acetates.

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

  In this invention, the preferable density | concentration of the polymer component containing the said polyamic acid in a liquid crystal aligning agent is 0.1 to 40 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. When the concentration of the polymer component is 40% by weight or less, the viscosity suitable for easily mixing the solvent with the liquid crystal aligning agent when the liquid crystal aligning agent needs to be diluted for film thickness adjustment. It is preferable from the viewpoint of adjusting the viscosity of the liquid crystal aligning agent.

  The concentration of the polymer component in the liquid crystal aligning agent may be adjusted by the application 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 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 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 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, it can be obtained by a step of forming a coating film of the liquid crystal aligning agent of the present invention and a step of heating and baking the same. 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 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, 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 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 2001-48 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.

  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 mixture of the compound (a) and the non-side chain diamine is used for the production of the liquid crystal alignment film of this element. A polyamic acid obtained by reacting with an anhydride is preferably used.

  Since the liquid crystal display element for the vertical electric field mode requires a relatively large pretilt angle, the liquid crystal alignment film of this element can be produced by using a mixture of the compound (a) and the side chain diamine, or the compound (a), side A polyamic acid obtained by reacting a mixture of a chain diamine and a non-side chain diamine with a tetracarboxylic dianhydride, or a mixture of the compound (a) and a side chain diamine with a tetracarboxylic dianhydride. A mixture of the polyamic acid obtained and a polyamic acid obtained by reacting a mixture of the compound (a) and the non-side chain diamine with tetracarboxylic dianhydride is preferably used.

  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 drive systems by appropriately selecting a polymer as the raw material.

  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.

The evaluation method of the liquid crystal display element used in the examples is shown below.
(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 the residual DC. It can be said that the smaller the residual DC is, the better the less seizure.
(2) Voltage holding ratio (VHR)
Measurement was performed at a frequency of 30 Hz, a voltage of ± 5 V, and a measurement temperature of 60 ° C. using a “6254 type liquid crystal physical property evaluation system” manufactured by Toyo Technica Co., Ltd.
(3) Ion density (ID)
Measurement was performed at a frequency of 0.01 Hz, a voltage of ± 10 V, and a measurement temperature of 60 ° C. using a “6254 type liquid crystal physical property evaluation system” manufactured by Toyo Technica Co., Ltd.
(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 tetracarboxylic dianhydride, diamine, and solvent used in Examples and Comparative Examples are shown below. In the following description, this compound number or abbreviation may be used.
<Tetracarboxylic dianhydride>
Compound (19): 1,2,3,4-cyclobutanetetracarboxylic dianhydride Compound (1): pyromellitic dianhydride Compound (23): 1,2,3,4-butanetetracarboxylic dianhydride <Diamine>
Compound (a-1): 3,5-diamino-1,2,4-triazole (a compound in which L ¹ is hydrogen in formula (a))
Compound (V-1): 4,4′-diaminodiphenylmethane Compound (V-7): 4,4′-diaminodiphenylethane Compound (VIII-5-1): 5- [4- (4-n-pentylcyclohexyl) ) Cyclohexyl] phenylmethyl-1,3-diaminobenzene (compound in which R ²³ is n-pentyl in formula (VIII-5))
Compound (IV-16): 2- (phenylmethyl) -1,4-diaminobenzene Compound (XI-2-1): 1,1-bis [4-[(4-aminophenyl) methyl] phenyl] -4 -N-butylcyclohexane (compound in which R ²⁹ is n-butyl in formula (XI-2))
Compound (XI-6-1): 1,1-bis [4- (4-aminophenoxy) phenyl] -4- [4- (n-heptyl) cyclohexylethyl] cyclohexane In the formula (XI-6), R Compound in which ³⁰ is n-heptyl)
<Epoxy compound>
Compound (E4): Epicoat 828 (Japan Epoxy Resin Co., Ltd.)
Compound (E5): 4,4′-methylenebis (N, N-diglycidylaniline)
<Solvent component>
NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BC: ethylene glycol monobutyl ether

[Synthesis Example 1]
<Preparation of liquid crystal alignment film composition A1 (varnish A1)>
0.125 g of compound (a-1), 2.26 g of compound (V-1), and 24 mL of dehydrated NMP in a 100 mL four-necked flask equipped with a thermometer, stirrer, raw material charging inlet and nitrogen gas inlet The mixture was dissolved under stirring in a dry nitrogen stream. While maintaining the temperature of the reaction system at 5 ° C., 1.24 g of compound (19) and 1.38 g of compound (1) were added and reacted for 30 hours, and then 13 mL of BC and 28 mL of GBL were added to increase the concentration of the polymer component. A 5% by weight polyamic acid solution was prepared. When the reaction temperature rises due to the heat of reaction during the reaction of the raw materials, the reaction was carried out while suppressing the reaction temperature to about 70 ° C.

  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 weight average molecular weight of the obtained polyamic acid was 61600. The weight average molecular weight of the polymer was determined by diluting the obtained polymer with a diluent (phosphoric acid / DMF = 0.6 / 100: weight ratio) so that the polymer concentration was about 1% by weight, and measured by GPC made by Waters. Using an apparatus (software Empower), the above dilution was used as a developing agent, measured by a GPC method at a column temperature of 50 ° C., and calculated by polystyrene conversion.

  The varnish obtained as described above was 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, and then applied. Varnish A1 for use.

[Synthesis Examples 2 to 6]
<Preparation of varnish A2-A6>
Varnishes A2 to A6 were prepared in the same manner as in Synthesis Example 1 except that the type and mixing ratio (mol%) of tetracarboxylic dianhydride and diamine were changed as shown in Table 1. The molar ratio of the total amount of tetracarboxylic dianhydride and the total amount of diamine is 1. The weight average molecular weight of the obtained polyamic acid is shown in Table 1.

<Table 1>

[Example 1]
<Production of characteristic measurement cell>
Varnish A1 obtained in Synthesis Example 1 was applied onto a glass substrate with an ITO electrode by 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 a 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 bonded together and 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. This cell was heat-treated at 110 ° C. for 30 minutes to obtain a characteristic measuring cell. 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.

<Liquid crystal composition A>

<Measurement of characteristics>
The pretilt angle, voltage holding ratio (VHR), ion density (ID), and residual DC were measured using the measurement cell. The results are shown in Table 2.

[Examples 2-3]
Using the varnishes A2 to A3 obtained in Synthesis Examples 2 to 3, a measurement cell was prepared in the same manner as in Example 1, and the pretilt angle, voltage holding ratio, ion density, and residual DC were measured in the same manner as in Example 1. . The measurement results are shown in Table 2.

<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, and it is good if the ion density is 50 pC or less. Furthermore, it is good if the residual DC is a value of 20 mV or less. 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. Further, 90 ° is preferable in the VA mode.

[Example 4]
A varnish was prepared by mixing varnish A1 and varnish A5 at A1 / A5 = 8/2 (weight ratio). A pretilt angle, a voltage holding ratio, an ion density, and a residual DC were measured in the same manner as in Example 1 for a characteristic measurement cell that was produced in the same manner as in Example 1. The results are shown below.
Pretilt angle: 7.3 °
Voltage holding ratio: 99.0%
Ion density: 38pC
Residual DC: 8 mV

[Example 5]
To 20 g of the varnish A2 obtained in Synthesis Example 2 (solid content concentration 5% by weight), 0.44′-methylenebis (N, N-diglycidylaniline) (manufactured by Sigma-Aldrich) as an epoxy compound was added to 0. 1 g (10% by weight based on the polymer of varnish A1) was added to prepare varnish B1. A pretilt angle, a voltage holding ratio, an ion density, and a residual DC were measured in the same manner as in Example 1 for a characteristic measurement cell that was produced in the same manner as in Example 1. The results are shown below.
Pretilt angle: 7.5 °
Voltage holding ratio: 99.3%
Ion density: 25 pC
Residual DC: 15 mV

[Example 6]
<Production of characteristic measurement cell>
Varnish B2 obtained by mixing varnishes A4 and A6 obtained in Synthesis Examples 4 and 6 at A4 / A6 = 9/1 (weight ratio) was applied onto a glass substrate with an ITO electrode using a spinner. The coating conditions were 1,700 rpm and 15 seconds. After the coating, it was pre-baked at 80 ° C. for about 3 minutes and then heat-treated at 180 ° C. for 20 minutes to form a liquid crystal alignment film having a thickness of about 70 nm.

  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 4 μm gap agent was sprayed on one glass substrate with an ITO electrode, and the other glass substrate with an ITO electrode was bonded together and sealed with an epoxy curing agent to produce a cell with a gap of 4 μm. A liquid crystal material 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 obtain a characteristic measurement cell. The composition of the liquid crystal composition B used as the liquid crystal material is shown below. The NI point of this composition was 75.4 ° C., and the birefringence was 0.081.

<Liquid crystal composition B>

<Measurement of characteristics>
The results of measuring the pretilt angle, voltage holding ratio, ion density, and residual DC using the above measurement cell are shown below.
Pretilt angle: 90 °
Voltage holding ratio: 99.4%
Ion density: 48pC
Residual DC: 5 mV

[Synthesis Examples 7 to 8]
<Preparation of varnish>
Varnishes C1 and C2 were prepared in the same manner as in Synthesis Example 1 except that the types and mixing ratios (mol%) of tetracarboxylic dianhydride and diamine were changed as shown in Table 3. The molar ratio of the total amount of tetracarboxylic dianhydride and the total amount of diamine is 1. Table 3 shows the weight average molecular weight of the obtained polyamic acid.
<Table 3>

[Comparative Examples 1-2]
Using the varnishes C1 and C2 obtained in Synthesis Examples 7 to 8 instead of the varnish A1, a measurement cell was prepared in the same manner as in Example 1, and the pretilt angle, voltage holding ratio, ion density, and residual DC were measured. . The measurement is shown in Table 4.
<Table 4>

[Comparative Example 3]
Using varnishes A6 and C1 obtained in Synthesis Examples 6 and 7, varnish C3 was prepared by mixing at a weight ratio of C1 / A6 = 9/1. A measurement cell was prepared in the same manner as in Example 6 using varnish C3. The pretilt angle, voltage holding ratio, ion density, and residual DC of this cell were measured in the same manner as in Example 1. The results are shown below.
Pretilt angle: 90 °
Voltage holding ratio: 98.4%
Ion density: 194pC
Residual DC: 24 mV

  As is clear from the results of Examples 1 to 6 and Comparative Examples 1 to 3, by using the liquid crystal aligning agent of the present invention, a liquid crystal display element that simultaneously satisfies a high voltage holding ratio, a low ion density, and a low residual DC is manufactured. can do.

[Synthesis Example 9]
<Preparation of polymer solution (D1)>
In a 100 ml four-necked flask equipped with a thermometer, stirrer, raw material charging inlet and nitrogen gas inlet, 0.137 g of compound (a-1), 2.9901 g of compound (VIII-5-1), compound 1.096 g of (IV-16) and 58.24 g of dehydrated NMP were added and dissolved by stirring under a dry nitrogen stream. Next, 0.548 g of the compound (23), 0.603 g of the compound (1) and 1.626 g of the compound (19) were added, and reacted for 30 hours in a room temperature environment. The compounding ratio (mol%) of the tetracarboxylic dianhydride used here is compound (1): compound (19): compound (23) = 20: 60: 20. The molar ratio between the total amount of tetracarboxylic dianhydride and the total amount of diamine is 1. 36.62 g of BC was added to the resulting solution to prepare a polymer solution (D1) having a polyamic acid concentration of 7% by weight. The weight average molecular weight of the produced polymer was 18,000.

[Synthesis Examples 10-15]
<Preparation of polymer solutions (D2) to (D7)>
The blending ratio of tetracarboxylic dianhydride was fixed to the same as in Synthesis Example 9, and the diamine was blended as shown in Table 5, and the polymer solutions (D2) to (D7) shown in Table 5 were prepared in the same manner as in Synthesis Example 9. Prepared. Table 5 shows the weight average molecular weight of the obtained polyamic acid.
<Table 5>

[Example 7]
<Production of characteristic measurement cell>
The polymer solution (D1) of Synthesis Example 9 and the polymer solution (D5) of Synthesis Example 13 were mixed at a weight ratio of 1: 9. The obtained mixed solution was diluted with a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a coating varnish having a polymer concentration of 4% by weight. This varnish was applied to two glass substrates with an ITO electrode with a spinner to form a film with a thickness of 70 nm. After coating, the film was heated and dried at 80 ° C. for about 5 minutes, and then heat-treated at 220 ° C. for 20 minutes to form a liquid crystal alignment film. The glass substrate on which the alignment film was formed was ultrasonically cleaned in ultrapure water for 5 minutes and then dried in an oven at 120 ° C. for 30 minutes. Next, a 4 μm gap material was sprayed on one glass substrate, and the surface on which the alignment film was formed was sealed inside with an epoxy curing agent to produce a cell with a gap of 4 μm. The following liquid crystal composition C was injected into this cell, and the injection port was sealed with a photocuring agent. Next, heat treatment was performed at 110 ° C. for 30 minutes, and a cell for characteristic measurement was produced. The NI point of the liquid crystal composition C was 75.4 ° C., and the birefringence was 0.081.

<Liquid crystal composition C>

<Measurement of characteristics>
For the obtained measurement cell, the pretilt angle, voltage holding ratio (VHR), ion density (ID), and residual DC were measured in the same manner as in Example 1. The results are shown in Table 6.

[Example 8]
The polymer solution (D2) of Synthesis Example 10 and the polymer solution (D4) of Synthesis Example 12 were mixed at a weight ratio of 9: 1. This mixed solution was diluted with a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a coating varnish having a polymer concentration of 4% by weight. Using this varnish, the pretilt angle, the voltage holding ratio (VHR), the ion density (ID), and the residual DC of the measurement cell produced in the same manner as in Example 7 were measured. The results are shown in Table 6.

[Example 9]
The polymer solution (D3) of Synthesis Example 11 and the polymer solution (D2) of Synthesis Example 10 were mixed at a weight ratio of 1: 9. This mixed solution was diluted with a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a coating varnish having a polymer concentration of 4% by weight. Using this varnish, the pretilt angle, the voltage holding ratio (VHR), the ion density (ID), and the residual DC of the measurement cell produced in the same manner as in Example 7 were measured. The results are shown in Table 6.

[Comparative Example 4]
The polymer solution (D4) of Synthesis Example 12 and the polymer solution (D5) of Synthesis Example 13 were mixed at a weight ratio of 1: 9. This mixed solution was diluted with a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a coating varnish having a polymer concentration of 4% by weight. Using this varnish, the pretilt angle, the voltage holding ratio (VHR), the ion density (ID), and the residual DC of the measurement cell produced in the same manner as in Example 7 were measured. The results are shown in Table 6.

[Comparative Example 5]
The polymer solution (D6) of Synthesis Example 14 and the polymer solution (D5) of Synthesis Example 13 were mixed at a weight ratio of 1: 9. This mixed solution was diluted with a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a coating varnish having a polymer concentration of 4% by weight. Using this varnish, the pretilt angle, the voltage holding ratio (VHR), the ion density (ID), and the residual DC of the measurement cell produced in the same manner as in Example 7 were measured. The results are shown in Table 6.

[Comparative Example 6]
The polymer solution (D7) of Synthesis Example 15 was diluted with a mixed solvent of NMP / BC = 1/1 (weight ratio) to obtain a coating varnish having a polymer concentration of 4% by weight. Using this varnish, the pretilt angle, the voltage holding ratio (VHR), the ion density (ID), and the residual DC of the measurement cell produced in the same manner as in Example 7 were measured. The results are shown in Table 6.

<Table 6>

  As is clear from the results of Examples 7 to 9 and Comparative Examples 4 to 6, the liquid crystal aligning agent of the present invention can reduce the residual DC even in a VA liquid crystal display element having a large pretilt angle, and the ion density. Give relatively good results.

[Examples 10 to 14 and Comparative Example 7]
A solution in which compound (E4) and compound (E5) were added as shown in Table 7 to a polymer solution having the same composition as the polymer solution of Example 9 was prepared. And the cell for a measurement was produced like Example 7 using these solutions, and ion density (ID) was measured about these cells. Thereafter, these cells were left in a thermostat set at 100 ° C. for 500 hours, and the ion density (ID) was measured again to calculate the degree of deterioration. The polymer solution of Example 9 and the polymer solution of Comparative Example 5 were similarly evaluated.
Degradation degree of ID = (measured value after putting in constant temperature layer) / (measured value before putting in constant temperature layer)

（注）添加量はポリマー溶液に対する重量比である。 <Table 7>

(Note) The amount added is a weight ratio to the polymer solution.

  Comparing Examples 10 to 14 with Comparative Example 7, it can be seen that the polymer containing compound (a-1) as a diamine raw material has an effect of preventing deterioration of the liquid crystal cell. Furthermore, deterioration can be suppressed by adding a compound having at least two oxiranyl groups. It can also be seen that the greater the amount of compound (E5) added, the higher the effect of preventing deterioration.

Claims (24)

A composition containing at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a mixture of a diamine represented by the formula (a) and another diamine with tetracarboxylic dianhydride and a derivative thereof. And the other diamine is at least one selected from the group of non-side chain diamines represented by formulas (I) to (VII), alkyl having 3 or more carbon atoms, alkoxy having 3 or more carbon atoms, carbon It is selected from an alkoxyalkyl having a number of 3 or more, a group having a steroid skeleton, and a ring-containing group having an alkyl having 3 or more carbons, an alkoxy having 3 or more carbons or an alkoxyalkyl having 3 or more carbons as a substituent on the terminal ring At least one side chain diamine having a side chain group, or at least one non-side chain diamine and at least one side chain diamine. The liquid crystal alignment agent is a mixture of:

Wherein L ¹ is hydrogen, alkyl having 1 to 4 carbon atoms, phenyl or benzyl; X ¹ is a linear alkylene having 2 to 12 carbon atoms; X ² is a linear alkylene having 1 to 12 carbon atoms. Yes; X ³ , X ⁴ and X ⁵ are independently a single bond, —O—, —CO—, —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. Wherein t is an integer from 1 to 12, and X ⁴ in formula (VI) and X ⁵ in formula (VII) may be the same or different; any hydrogen on the cyclohexane ring or benzene ring is fluorine _{, -CH 3, -OH, -COOH,} -SO 3 H, -PO 3 H 2, benzyl Or may be replaced by hydroxybenzyl. The liquid crystal aligning agent of Claim 1 whose side chain type diamine is diamine chosen from the group of the compound represented by Formula (VIII)-Formula (XII).

(Here, ^{R 1} is a single bond, -O -, - CO -, - COO -, - OCO -, - CONH -, - CH 2 O -, - CF 2 O-, or an alkylene having 1 to 6 carbon atoms And any —CH ₂ — in the alkylene may be replaced by —O—, —CH═CH— or —C≡C—; R ² is a group having a steroid skeleton, having 3 to 30 carbon atoms Alkyl having 3 to 30 carbon atoms or phenyl having 3 to 30 carbon atoms as a substituent, or a group represented by formula (D-1), and any- CH ₂ — may be replaced by —O—, —CH═CH— or —C≡C—;

Here, R ¹³ , R ¹⁴ and R ¹⁵ are each independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or ring C and C are independently 1,4-phenylene or 1,4-cyclohexylene; R ¹⁶ and R ¹⁷ are independently fluorine or methyl; M1 and m2 are independently 0, 1 or 2; e, f and g are each independently an integer of 0 to 3, and their sum is 1 or more; R ¹⁸ is carbon number An alkyl having 3 to 30 carbons, an alkoxy having 3 to 30 carbons, or an alkoxyalkyl having 3 to 30 carbons, and in these alkyls, alkoxys and alkoxyalkyls, any hydrogen is replaced by fluorine. And any —CH ₂ — may be replaced by difluoromethylene or a group represented by formula (D-2);

Here, R ¹⁹ , R ²⁰ , R ²¹ and R ²² are independently alkyl having 1 to 10 carbons or phenyl, and n is an integer of 1 to 100. )

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; and R ⁵ is independently a single bond. , -CO- or -CH ₂ - is).

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; R ⁵ is independently a single bond, — CO— or —CH ₂ —; and R ⁶ and R ⁷ are independently hydrogen, alkyl having 1 to 30 carbons, or phenyl.)

(Wherein R ⁸ is alkyl having 3 to 30 carbon atoms, and any —CH ₂ — in the alkyl may be replaced by —O—, —CH═CH— or —C≡C—; R ⁹ is independently —O— or alkylene having 1 to 6 carbons; Ring A is 1,4-phenylene or 1,4-cyclohexylene; a is 0 or 1; b is 0; 1 or 2; and c is independently 0 or 1.)

(Where R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms; R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms or fluorinated alkyl having 1 to 30 carbon atoms. Yes; R ¹² is independently —O— or alkylene having 1 to 6 carbons; and d is independently 0 or 1. The non-side chain diamine is represented by formula (IV-1), formula (IV-2), formula (IV-15), formula (IV-16), formula (V-1) to formula (V-12), formula (IV) V-33) and a diamine selected from the compounds represented by formula (VII-2), and the side chain diamine is represented by formula (VIII-2), formula (VIII-4), formula (VIII-5), formula The liquid crystal aligning agent of Claim 1 which is a diamine chosen from the compound represented by (VIII-6), Formula (XI-2), and Formula (XI-4).

(Here, R ²³ , R ²⁴ , R ²⁹ and R ³⁰ are each independently alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms.) Tetracarboxylic dianhydride is represented by formula (1), formula (2), formula (5) to formula (9), formula (14), formula (19), formula (23), formula (25), formula (35). The liquid crystal according to any one of claims 1 to 3, which is at least one selected from the compounds represented by formula (37), formula (39), formula (44) and formula (49). Alignment agent.

The tetracarboxylic dianhydride is at least one selected from compounds represented by formula (1), formula (6) to formula (9), formula (19), formula (23) and formula (25). The liquid crystal aligning agent of any one of Claims 1-3.

The liquid crystal according to any one of claims 1 to 3, wherein the tetracarboxylic dianhydride is at least one selected from compounds represented by formula (1), formula (19), and formula (23). Alignment agent.

  The content rate of the diamine represented by Formula (a) is 1-50 mol% on the basis of the diamine whole quantity, The content rate of other diamine is 50-99 mol%, Any one of Claims 1-6 Item 1. A liquid crystal aligning agent according to item 1.   At least one polymer selected from the group consisting of a polyamic acid obtained by reacting a mixture of a diamine represented by formula (a) and a non-side chain diamine with tetracarboxylic dianhydride and a derivative thereof; It contains at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a mixture of a diamine represented by a) and a side chain diamine with a tetracarboxylic dianhydride and a derivative thereof. The liquid crystal aligning agent of 1. The non-side chain diamine is represented by formula (IV-1), formula (IV-2), formula (IV-15), formula (IV-16), formula (V-1) to formula (V-12), formula (IV) V-33) and a diamine selected from the compounds represented by formula (VII-2), and the side chain diamine is represented by formula (VIII-2), formula (VIII-4), formula (VIII-5), formula The liquid crystal aligning agent of Claim 8 which is a diamine chosen from the compound represented by (VIII-6), Formula (XI-2), and Formula (XI-4).

(Here, R ²³ , R ²⁴ , R ²⁹ and R ³⁰ are each independently alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms.) The tetracarboxylic dianhydride is at least one selected from compounds represented by formula (1), formula (6) to formula (9), formula (19), formula (23) and formula (25). The liquid crystal aligning agent of Claim 8 or 9.

  It further contains at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a diamine other than the diamine represented by formula (a) with tetracarboxylic dianhydride and a derivative thereof. The liquid crystal aligning agent of any one of 6 and 8-10. A diamine other than the diamine represented by formula (a) is at least one selected from the group of non-side chain diamines represented by formula (I) to formula (VII), an alkyl having 3 or more carbon atoms, and 3 carbon atoms. A ring having a terminal ring having the above alkoxy, an alkoxyalkyl having 3 or more carbon atoms, a group having a steroid skeleton, and an alkyl having 3 or more carbon atoms, an alkoxy having 3 or more carbon atoms or an alkoxyalkyl having 3 or more carbon atoms as a substituent. The liquid crystal aligning agent according to claim 11, wherein the liquid crystal aligning agent is at least one side chain diamine having a side chain group selected from the containing groups, or a mixture of at least one non-side chain diamine and side chain diamine. :

Wherein X ¹ is a linear alkylene having 2 to 12 carbon atoms; X ² is a linear alkylene having 1 to 12 carbon atoms; X ³ , X ⁴ and X ⁵ are independently a single bond, —O -, - CO -, - 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, and in the formula (VI) X ⁴ and X ⁵ in formula (VII) may be the same or different; any hydrogen of the cyclohexane ring or the benzene ring is fluorine, —CH ₃ , —OH, —COOH, —SO ₃ H, —PO ₃ H _2, may be replaced by benzyl or hydroxybenzyl. The liquid crystal aligning agent of Claim 12 whose side chain type diamine is diamine chosen from the group of the compound represented by Formula (VIII)-Formula (XII).

(Here, ^{R 1} is a single bond, -O -, - CO -, - COO -, - OCO -, - CONH -, - CH 2 O -, - CF 2 O-, or an alkylene having 1 to 6 carbon atoms And any —CH ₂ — in the alkylene may be replaced by —O—, —CH═CH— or —C≡C—; R ² is a group having a steroid skeleton, having 3 to 30 carbon atoms Alkyl having 3 to 30 carbon atoms or phenyl having 3 to 30 carbon atoms as a substituent, or a group represented by formula (D-1), and any- CH ₂ — may be replaced by —O—, —CH═CH— or —C≡C—;

Here, R ¹³ , R ¹⁴ and R ¹⁵ are each independently a single bond, —O—, —COO—, —OCO—, —CONH—, alkylene having 1 to 4 carbons, or oxyalkylene having 1 to 3 carbons. Or ring C and C are independently 1,4-phenylene or 1,4-cyclohexylene; R ¹⁶ and R ¹⁷ are independently fluorine or methyl; M1 and m2 are independently 0, 1 or 2; e, f and g are each independently an integer of 0 to 3, and their sum is 1 or more; R ¹⁸ is carbon number An alkyl having 3 to 30 carbons, an alkoxy having 3 to 30 carbons, or an alkoxyalkyl having 3 to 30 carbons, and in these alkyls, alkoxys and alkoxyalkyls, any hydrogen is replaced by fluorine. And any —CH ₂ — may be replaced by difluoromethylene or a group represented by formula (D-2);

Here, R ¹⁹ , R ²⁰ , R ²¹ and R ²² are independently alkyl having 1 to 10 carbons or phenyl, and n is an integer of 1 to 100. )

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; and R ⁵ is independently a single bond. , -CO- or -CH ₂ - is).

(Wherein R ³ is independently hydrogen or methyl; R ⁴ is hydrogen, alkyl having 1 to 30 carbons, or alkenyl having 2 to 30 carbons; R ⁵ is independently a single bond, — CO— or —CH ₂ —; and R ⁶ and R ⁷ are independently hydrogen, alkyl having 1 to 30 carbons, or phenyl.)

(Wherein R ⁸ is alkyl having 3 to 30 carbon atoms, and any —CH ₂ — in the alkyl may be replaced by —O—, —CH═CH— or —C≡C—; R ⁹ is independently —O— or alkylene having 1 to 6 carbons; Ring A is 1,4-phenylene or 1,4-cyclohexylene; a is 0 or 1; b is 0; 1 or 2; and c is independently 0 or 1.)

(Where R ¹⁰ is alkyl having 3 to 30 carbon atoms or fluorinated alkyl having 3 to 30 carbon atoms; R ¹¹ is hydrogen, alkyl having 1 to 30 carbon atoms or fluorinated alkyl having 1 to 30 carbon atoms. Yes; R ¹² is independently —O— or alkylene having 1 to 6 carbons; and d is independently 0 or 1. The non-side chain diamine is represented by formula (IV-1), formula (IV-2), formula (IV-15), formula (IV-16), formula (V-1) to formula (V-12), formula (IV) V-33) and a diamine selected from the compounds represented by formula (VII-2), and the side chain diamine is represented by formula (VIII-2), formula (VIII-4), formula (VIII-5), formula The liquid crystal aligning agent of Claim 12 which is a diamine chosen from the compound represented by (VIII-6), Formula (XI-2), and Formula (XI-4).

(Here, R ²³ , R ²⁴ , R ²⁹ and R ³⁰ are each independently alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms.) Tetracarboxylic dianhydride is represented by formula (1), formula (2), formula (5) to formula (9), formula (14), formula (19), formula (23), formula (25), formula (35). The liquid crystal according to any one of claims 12 to 14, which is at least one selected from the compounds represented by formula (37), formula (39), formula (44) and formula (49). Alignment agent.

The tetracarboxylic dianhydride is at least one selected from compounds represented by formula (1), formula (6) to formula (9), formula (19), formula (23) and formula (25). The liquid crystal aligning agent of any one of Claims 12-14.

The liquid crystal according to any one of claims 12 to 14, wherein the tetracarboxylic dianhydride is at least one selected from compounds represented by formula (1), formula (19), and formula (23). Alignment agent.

  The liquid crystal aligning agent of any one of Claims 1-6 which further contains the compound which has at least 2 oxiranyl group.   The liquid crystal aligning agent of any one of Claims 8-10 which further contains the compound which has an at least 2 oxiranyl group.   The liquid crystal aligning agent of any one of Claims 11-17 which further contains the compound which has at least 2 oxiranyl group. 21. The liquid crystal aligning agent according to any one of claims 18 to 20, wherein the compound having at least two oxiranyl groups is at least one selected from compounds represented by formulas (E1) to (E5).

(Here, n is an integer from 0 to 10.)   The ratio of the compound having at least two oxiranyl groups is 0.001 to 0.40 in a weight ratio with respect to the total amount of at least one polymer selected from the group consisting of polyamic acid and derivatives thereof. 2. A liquid crystal aligning agent according to item 1.   The liquid crystal aligning film obtained from the liquid crystal aligning agent of any one of Claims 1-22.   24. The liquid crystal alignment film according to claim 23, comprising a pair of substrates, a liquid crystal layer sandwiched between the substrates, and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal alignment film according to claim 23 is formed on a surface in contact with the liquid crystal layer of the substrate. Liquid crystal display element.