JP2010102184A - Liquid crystal aligning agent, liquid crystal alignment layer, and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display element which is low in residual voltage, is excellent in long-term reliability, and is applicable to various driving modes. <P>SOLUTION: The liquid crystal alignment layer is formed by using the liquid crystal aligning agent containing a polyamic acid which is a reaction product of a predetermined diamine and a tetracarboxylic acid dianhydride or a derivative thereof, and an epoxy compound having two or more epoxy groups, and the liquid crystal display element having the liquid crystal alignment layer is constructed thereby. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal aligning agent containing a polyamic acid or a derivative thereof and an epoxy compound, a liquid crystal alignment film formed from the liquid crystal aligning agent, and a liquid crystal display device including the same.

  Liquid crystal display elements are used in various liquid crystal display devices such as monitors for notebook computers and desktop computers, video camera viewfinders, and projection displays. Recently, they have also been used as televisions. . Furthermore, liquid crystal display elements are also used as optoelectronic-related elements such as optical printer heads, optical Fourier transform elements, and light valves.

  The liquid crystal display element usually has 1) a pair of substrates arranged opposite to each other, 2) electrodes formed on one or both of the opposed surfaces of each of the pair of substrates, and 3) each of the pair of substrates. And 4) a liquid crystal layer formed between the pair of substrates.

  As a conventional liquid crystal display element, a display element using a nematic liquid crystal is a mainstream, and 1) a TN (twisted nematic) type liquid crystal display element twisted by 90 degrees, and 2) a STN (super twisted nematic) twisted usually by 180 degrees or more. 3) A so-called TFT (Thin Film Transistor) type liquid crystal display element using a thin film transistor has been put into practical use. These liquid crystal display elements have a drawback that a viewing angle at which an image can be properly viewed is narrow, and when viewed from an oblique direction, luminance and contrast decrease and luminance inversion occurs in a halftone.

  In recent years, the problem of viewing angle is as follows: 1) TN-TFT type liquid crystal display element using optical compensation film, 2) VA (vertical alignment) type liquid crystal display element using vertical alignment and optical compensation film, 3) vertical MVA (Multi Domain Vertical Alignment) type liquid crystal display element using alignment and protrusion structure technology together, or 4) IPS (In-Plane Switching) type liquid crystal display element of lateral electric field type, 5) ECB (Electrically Controlled Birefringence type) Liquid crystal display element, 6) Optically compensated bend (Optically self-compensated birefringence: OCB) type liquid crystal It has been improved by techniques such as display elements, and the improved techniques have been put into practical use or are being studied.

  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.

The liquid crystal alignment film is prepared from a liquid crystal aligning agent. The liquid crystal aligning agent mainly used at present is a solution in which polyamic acid or soluble polyimide is dissolved in an organic solvent. After applying such a solution to a substrate, a polyimide-based alignment film is formed by film formation by means such as heating. As such a liquid crystal aligning agent, for example, a liquid crystal aligning agent in which a tetracarboxylic dianhydride and a diamine which are raw materials of polyamic acid or a derivative thereof and a pretilt angle to be expressed is defined (for example, , See Patent Document 1). Various liquid crystal aligning agents other than polyamic acid are also being studied, but they are almost practical in terms of heat resistance, chemical resistance (liquid crystal resistance), coating properties, liquid crystal alignment properties, electrical properties, optical properties, display properties, etc. It has not been converted.

  An important characteristic required for the liquid crystal alignment film in order to improve the display quality of the liquid crystal display element is a residual voltage. This characteristic of residual voltage is a problem common to all liquid crystal display elements, and is related to a phenomenon called burn-in in which the same image is displayed as an afterimage when the same screen is displayed for a long time and then moved to another screen. The image sticking is considered to occur because a predetermined voltage is not applied to the liquid crystal molecules due to charge accumulation such as impurity ions contained in the liquid crystal on the alignment film surface, that is, a residual voltage. In order to obtain a high-quality liquid crystal display element, it is very important to improve the image sticking.

As an attempt to solve the above problems, for example, a liquid crystal aligning agent containing polyamic acid or polyimide which is a reaction product of a linear diamine containing sulfur in the main chain and tetracarboxylic dianhydride is known. (For example, refer to Patent Document 1).
However, further improvement in display quality in liquid crystal display elements is required, and development of a liquid crystal aligning agent that can provide a liquid crystal display element with higher performance is still required.
JP 2006-220676 A

  In view of the above situation, it is desired to develop a liquid crystal aligning agent for a liquid crystal display element in which the problem of image sticking is improved, a liquid crystal alignment film formed using the same, and a liquid crystal display element including the same.

The present inventors have intensively studied to solve the above problems.
As a result, it has been found that a liquid crystal aligning agent containing a specific polyamic acid or a derivative thereof and a specific epoxy compound can reduce the residual voltage of a liquid crystal display device comprising a liquid crystal alignment film produced using this, The present invention has been completed.
The present invention has the following configuration.

（一般式（Ｉ）中、−Ｘ¹−は、−Ｓ−、または−Ｓ−（ＣＨ₂）_n−Ｓ−で表される２価の基であり、ｎは１〜１６の整数である。） (1) A liquid crystal aligning agent comprising polyamic acid or a derivative thereof, which is a reaction product of diamine or a derivative thereof and tetracarboxylic acid or a derivative thereof, and an epoxy compound having two or more epoxy groups,
The diamine or a derivative thereof is a liquid crystal aligning agent containing a diamine represented by the following general formula (I).

(In the general formula (I), -X ¹ - is, -S-, or -S- (CH ₂₎ a bivalent group represented by _n -S-, n is 1 to 16 integer .)

(2) -X ^{1-of the} diamine represented by the general formula (I) is -S-, -S-CH ₂ -S-, -S- (CH ₂ ) ₂ -S-, -S- ( _{CH 2) 3 -S -, -} S- (CH 2) 4 -S -, - S- (CH 2) according to ₅ -S- or -S- (CH _{2) 6} a -S- (1) Liquid crystal aligning agent.

(3) —X ¹ — of the diamine represented by the general formula (I) is —S—, —S—CH ₂ —S—, —S— (CH ₂ ) ₂ —S—, —S— ( _{CH 2) 3 -S -, -} S- (CH 2) liquid crystal aligning agent according to ₄ -S- or -S- (CH _{2) 5} is -S- (1).

(4) The tetracarboxylic acid or a derivative thereof includes one or more of tetracarboxylic dianhydrides represented by the following structural formulas (1), (14), and (i), and the diamine or a derivative thereof is further The liquid crystal aligning agent in any one of (1)-(3) containing 1 or more types of diamine represented by general formula (A)-(D) and (XII-A).

（一般式（Ａ）中、ｎは、１から１２の整数である。一般式（Ｂ１）、（Ｂ２）及び（Ｂ３）中、−Ｙ¹、−Ｙ²、および−Ｙ³はそれぞれ独立して、−Ｈまたは炭素数１から３０のアルキルである。一般式（Ｄ）中、Ａ¹は独立して、−（ＣＨ₂）_m−又は−Ｎ（ＣＨ₃）−（ＣＨ₂）_m−Ｎ（ＣＨ₃）−を表す。ここでｍは１〜１２の整数を表す。一般式（ＸＩＩ−Ａ）中、−Ｙ⁴は炭素数１から３０のアルキル、

、または

であり、−Ｙ⁵および−Ｙ⁶はそれぞれ独立して炭素数１から３０のアルキルであり、Ｘ²は−ＣＨ₂−又は−Ｏ−を表わす。）

(In the general formula (A), n is an integer from 1 to 12. Formula (B1), (B2) and (B3) in, -Y ^1, -Y ^2, and -Y ³ are each independently -H or alkyl having 1 to 30 carbon atoms, and in general formula (D), A ¹ is independently-(CH ₂ ) _m -or -N (CH ₃ )-(CH ₂ ) _m-. Represents N (CH ₃ ) —, where m represents an integer of 1 to 12. In the general formula (XII-A), —Y ⁴ represents an alkyl having 1 to 30 carbon atoms;

Or

In and, -Y ⁵ and -Y ⁶ are each independently alkyl having 1 to 30 carbon atoms, X ² is -CH ₂ - represents or -O-. )

(5) The diamines represented by the general formulas (A) to (D) and (XII-A) are represented by the following structural formulas (A1), (B1-1), (B2-1), (B3-1), (C1), (C2), (C3), (D1), (D2), (D3), (D4), (XII-2-1), (XII-4-1) and (XII-7-1) The liquid crystal aligning agent as described in (4) which is 1 or more types of diamine represented by this.

(6) The diamine or derivative thereof has the following structural formulas (A1), (C1), (C2), (C
3) The liquid crystal aligning agent as described in (5) which is 1 or more types of diamine represented by (D1) and (D2).

(7) The liquid crystal aligning agent as described in (6) whose said diamine or its derivative (s) is 1 or more types of diamine represented by following structural formula (A1), (D1), and (D2).

(8) The diamine or derivative thereof is represented by the following structural formulas (D2), (D3), (D4), (XII-2-1), (XII-4-1), and (XII-7-1). The liquid crystal aligning agent as described in (5) which is 1 or more types of diamines.

(9) The diamine or derivative thereof is described in (8), which is one or more diamines represented by the following structural formulas (XII-2-1), (XII-4-1), and (XII-7-1). Liquid crystal aligning agent.

(10) The liquid crystal according to (5), wherein the diamine or derivative thereof is one or more diamines represented by the following structural formulas (B1-1), (B2-1), (B3-1), and (D1). Alignment agent.

(11) One or more diamines represented by the structural formulas (B1-1), (B2-1), (B3-1), and (D1) are diamines represented by the structural formula (B1-1). One or more tetracarboxylic dianhydrides represented by the structural formulas (1), (14) and (i) are tetracarboxylic dianhydrides represented by the structural formula (14). The liquid crystal aligning agent of description.

(12) The epoxy compound is selected from the group consisting of glycidyl ether, glycidyl ester, glycidyl amine, epoxy group-containing acrylic resin, glycidyl amide, glycidyl isocyanurate, chain aliphatic epoxy compound, and cyclic aliphatic epoxy compound. The liquid crystal aligning agent in any one of (1)-(11) which is one or more selected.

(13) The epoxy compound is N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, 2- [4- (2,3-epoxypropoxy) phenyl] -2- [4- [1,1-bis [4-([2,3- Epoxypropoxy] phenyl)] ethyl] phenyl] propane, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, N-phenylmaleimide-glycidyl methacrylate copolymer, bisphenol A novolac type epoxy compound, Cresol novolac-type epoxy compound and N, N, O-triglycidyl-p-aminophenol The liquid crystal aligning agent according to, characterized in that at al one or more selected (12).

(14) A liquid crystal alignment film formed by firing the liquid crystal aligning agent film according to any one of (1) to (13).

(15) A pair of substrates disposed opposite to each other, electrodes formed on one or both of the surfaces facing each other of the pair of substrates, and surfaces facing each of the pair of substrates. A liquid crystal display element having a liquid crystal alignment film and a liquid crystal layer formed between the pair of substrates, wherein the liquid crystal alignment film is the liquid crystal alignment film according to (14). element.

  In the present specification, the terms “alkyl”, “alkenyl”, and “alkynyl” may be linear or branched.

  The present invention can provide liquid crystal display elements of various driving systems that have a low residual voltage and are less likely to cause a burn-in problem.

  The liquid crystal aligning agent of this invention contains polyamic acid or its derivative (s), and the epoxy compound which has a 2 or more epoxy group. One or more polyamic acids or derivatives thereof may be used. The epoxy compound may be one type or two or more types. The content of the polyamic acid or derivative thereof is preferably 0.1 to 50% by weight, more preferably 1 to 30% by weight in the liquid crystal aligning agent. Moreover, it is preferable that it is 0.1-100 weight part with respect to 100 weight part of said polyamic acids or its derivative (s), and, as for content of the said epoxy compound, it is more preferable that it is 0.5-80 weight part.

  The polyamic acid and its derivative are reaction products of diamine or its derivative and tetracarboxylic acid or its derivative. The derivative of the polyamic acid is a form dissolved in a solvent when the liquid crystal aligning agent described later is used, and when the liquid crystal aligning agent is used as a liquid crystal aligning film described later, a liquid crystal aligning film mainly composed of polyimide is used. It is a component that can be formed. Examples of such polyamic acid derivatives include soluble polyimides, polyamic acid esters, polyamic acid amides, and the like. More specifically, 1) polyimide in which all amino acids and carboxyls of polyamic acid are subjected to a dehydration ring-closing reaction, 2) Partially dehydrated ring-closing partial polyimide, 3) Polyamic acid ester in which carboxyl of polyamic acid is converted to ester, 4) Part of acid dianhydride contained in tetracarboxylic dianhydride compound is organic dicarboxylic A polyamic acid-polyamide copolymer obtained by reacting with an acid, and 5) a polyamideimide obtained by subjecting a part or all of the polyamic acid-polyamide copolymer to a dehydration ring-closing reaction.

  In the polyamic acid or derivative thereof, the tetracarboxylic acid or derivative thereof and the diamine or derivative thereof are preferably 0.8: 1.2 to 1.2: 0.8 in molar ratio, : 1.1 to 1.1: 0.9 is more preferable.

  Although the said diamine or its derivative may be 1 type, or 2 or more types, it contains the sulfide-containing diamine represented by the following general formula (I). The diamine represented by the general formula (I) may be one kind or two or more kinds. In the diamine, the diamine represented by the general formula (I) is preferably 0.5 to 100 mol%, and more preferably 1 to 100 mol%.

In the general formula (I), -X ¹ - is, -S-, or -S- (CH ₂₎ a bivalent group represented by _n -S-, n is 1 to 16 integer.

In the diamine represented by the general formula (I), for example, as represented by the following structural formulas (I-1) to (I-6), —X ¹ — is —S—, —S—CH ₂ —. _{S -, - S- (CH 2} ) 2 -S -, - S- (CH 2) 3 -S -, - S- (CH 2) 4 -S -, - S- (CH 2) 5 -S- or -S- (CH _{2) 6} is preferably -S-.

  As the diamine represented by the general formula (I), diamines represented by the structural formulas (I-1) to (I-5) are particularly preferably used.

  The diamine or derivative thereof may further contain a diamine other than the diamine represented by the general formula (I). Examples of such other diamines include diamines represented by the following general formulas (A) to (D) and the following general formulas (II) to (XIII) and (XV).

（一般式（Ａ）中、ｎは、１から１２の整数である。一般式（Ｂ１）、（Ｂ２）及び（Ｂ３）中、−Ｙ¹、−Ｙ²、および−Ｙ³はそれぞれ独立して、−Ｈまたは炭素数１から３０のアルキルである。一般式（Ｄ）中、Ａ¹は独立して、−（ＣＨ₂）_m−又は−Ｎ（ＣＨ₃）−（ＣＨ₂）_m−Ｎ（ＣＨ₃）−を表す。ここでｍは１〜１２の整数を表す。）

(In the general formula (A), n is an integer from 1 to 12. Formula (B1), (B2) and (B3) in, -Y ^1, -Y ^2, and -Y ³ are each independently -H or alkyl having 1 to 30 carbon atoms, and in general formula (D), A ¹ is independently-(CH ₂ ) _m -or -N (CH ₃ )-(CH ₂ ) _m-. N (CH ₃ ) —, where m represents an integer of 1 to 12.

As the diamine represented by the general formula (A), for example, a diamine represented by the following structural formula (A1) is preferably used.

As the diamines represented by the general formulas (B1) to (B3), for example, diamines represented by the following structural formulas (B1-1) to (B3-1) are preferably used.

As the diamine represented by the general formula (C), for example, diamines represented by the following structural formulas (C1) to (C3) are preferably used.

As the diamine represented by the general formula (D), for example, diamines represented by the following structural formulas (D1) to (D4) are preferably used.

  Examples of the diamine other than the diamine represented by the general formula (I) include linear diamines represented by the following general formulas (II) to (VIII). The linear diamine may be one kind or two or more kinds.

In the general formula (II), A ¹ is, - (CH _{2) m} - represents a. Here, m represents an integer of 1 to 12. A ¹ in the general formula (IV) is independently a single bond, —O—, —S—, —S—S—, —SO ₂ —, —CO—, —CONH—, —NHCO—, _{-C (CH 3) 2 -,} - C (CF 3) 2 -, - (CH 2) m -, - O- (CH 2) m -O -, - N (CH 3) - (CH 2) m _{-N (CH 3) -, -} S- (CH 2) represents an _m -S-. A ^{1 ′} in the general formula (VI) is independently a single bond, —S—, —S—S—, —SO ₂ —, —CO—, —CONH—, —NHCO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —O— (CH ₂ ) _m —O—, and —S— (CH ₂ ) _m —S—. Here, m represents an integer of 1 to 12.

In general formula (VII), A ² independently represents —S—, —CO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ — or alkylene having 1 to 3 carbon atoms. .

In the general formula (VIII), A ¹ is independently —S—, —SS—, —SO ₂ —, —CO—, —CONH—, —NHCO—, —C (CF ₃ ) ₂ —. _{, -O- (CH 2) m -O} -, - S- (CH 2) represents an _m -S-. Here, m represents an integer of 1 to 12. In General Formula (VIII), A ² is a single bond, —O—, —S—, —CO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, or C 1 to C 3. Represents alkylene.

Hydrogen which is further coupled to the general formula (III) ~ (VIII) cyclohexane ring or a benzene ring in is independently _{-F, -Cl, -CH 3, -OH} , -COOH, -SO 3 H, - It may be replaced with PO ₃ H ₂ or 4-hydroxybenzyl.

  Examples of the linear diamine represented by the general formula (II) include diamines represented by the following structural formulas (II-1) to (II-3).

  Examples of the linear diamine represented by the general formula (III) include diamines represented by the following structural formulas (III-1) and (III-2).

  Examples of the linear diamine represented by the general formula (VI) include diamines represented by the following structural formulas (IV-1) to (IV-3).

  Examples of the linear diamine represented by the general formula (V) include diamines represented by the following structural formulas (V-1) to (V-14).

  Examples of the linear diamine represented by the general formula (VI) include diamines represented by the following structural formulas (VI-1) to (VI-27).

  Examples of the linear diamine represented by the general formula (VII) include diamines represented by the following structural formulas (VII-1) to (VII-6).

  Examples of the linear diamine represented by the general formula (VIII) include diamines represented by the following structural formulas (VIII-1) to (VIII-6).

  Of these, more preferred linear diamines include the structural formulas (V-1) to (V-5), (VI-1) to (VI-10), (VI-21), and (VI-22). ), (VI-26), (VII-1), (VII-2), (VII-6), and diamines represented by (VIII-1), and more preferable linear diamines include Examples include diamines represented by the structural formulas (V-1), (V-2), (VI-1) to (VI-10), and (VI-26).

  The molar ratio of the linear diamine in the diamine is preferably 1 to 90% in TN and IPS, and 5 to 80% from the viewpoint of obtaining appropriate orientation when a liquid crystal display device is obtained. More preferably.

  In applications that require a large pretilt angle, such as VA liquid crystal display elements, OCB liquid crystal display elements, TN liquid crystal display elements, and STN liquid crystal display elements, the diamine preferably contains a diamine having a side chain structure. Therefore, a diamine having such a side chain structure can be used as another diamine other than the diamine represented by the general formula (I). Examples of the diamine having such a side chain structure include side chain diamines represented by the following general formulas (IX) to (XIII). One or two or more side chain diamines may be used.

In General Formula (IX), A ³ represents a single bond, —O—, —COO—, —OCO—, —CO—, —CONH—, or — (CH ₂ ) _m —. Here, m represents an integer of 1 to 6. R ⁷ represents a group having a steroid skeleton, a group represented by the following general formula (XIV), or alkyl having 1 to 30 carbon atoms. In the alkyl, any —CH ₂ — may be independently replaced by —CF ₂ —, —CHF—, —O—, —CH═CH— or —C≡C—, ₃ may be replaced by —CH ₂ F, —CHF ₂ or —CF ₃ . However, -O- is not adjacent in the alkyl.

In general formula (XIV), A ⁴ and A ⁵ are each independently a single bond, —O—, —COO—, —OCO—, —CONH—, —CH═CH—, or alkylene having 1 to 20 carbon atoms. Represents. R ⁸ and R ⁹ each independently represents —F or —CH ₃ . Ring S is 1,4-phenylene, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, naphthalene-1,5- Represents diyl, naphthalene-2,7-diyl or anthracene-9,10-diyl. R ¹⁰ represents -F, alkyl having 1 to 30 carbon atoms, a fluorine-substituted alkyl having 1 to 30 carbon atoms, alkoxy having 1 to 30 carbon atoms, -CN, a -OCH ₂ F, -OCHF ₂ or -OCF _3. A and b each independently represent an integer of 0 to 4, and when a or b is 2 to 4, adjacent A ⁴ or A ⁵ are different groups, and c, d and e are each independently Represents an integer of 0 to 3, and when e is 2 or 3, the plurality of rings S may be the same group or different groups. f and g each independently represent an integer of 0 to 2 and c + d + e ≧ 1.

In general formula (X), the hydrogen bonded to the carbon forming the steroid skeleton may be independently replaced with —CH ₃ . In the general formulas (X) and (XI), R ¹¹ independently represents —H or —CH ₃ , and R ¹² represents —H or C 1-20 alkyl or alkenyl. A ⁶ each independently represents a single bond, —C (═O) — or —CH ₂ —. In General Formula (XI), R ¹³ and R ¹⁴ each independently represent —H, C 1-20 alkyl or phenyl.

In the general formula (XII), R ¹⁵ represents —H or alkyl having 1 to 30 carbons. Arbitrary —CH ₂ — in the alkyl having 2 to 30 carbon atoms out of the alkyl may be independently replaced by —O—, —CH═CH— or —C≡C—. However, -O- is not adjacent in the alkyl. In general formulas (XII) and (XIII), A ⁷ independently represents —O— or alkylene having 1 to 6 carbon atoms. In General Formula (XII), A ⁸ represents a single bond or alkylene having 1 to 3 carbon atoms. Ring T represents 1,4-phenylene or 1,4-cyclohexylene. h represents 0 or 1; In General Formula (XIII), R ¹⁶ represents alkyl having 6 to 22 carbon atoms, and R ¹⁷ represents —H or alkyl having 1 to 22 carbon atoms.

In the side chain diamine represented by the general formula (IX), it is preferable that the bonding position relationship between the two amino groups in which the two amino groups are bonded to the carbon of the phenyl ring is meta or para. Further binding positional relationship between the two amino groups, "R ⁷ -A ³ -" 3-position when the 1-position of the bond position of the 5-position, or is preferably 2-position and 5-position.

  Examples of the diamine represented by the general formula (IX) include diamines represented by the following general formulas (IX-1) to (IX-9).

In the general formulas (IX-1), (IX-2), (IX-5) and (IX-6), R ¹⁸ is preferably alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons, and carbon C3-C30 alkyl or C3-C30 alkoxy is more preferable, C5-C25 alkyl or C5-C25 alkoxy is still more preferable. In the general formulas (IX-3), (IX-4) and (IX-7) to (IX-9), R ¹⁹ is preferably alkyl having 1 to 30 carbons or alkoxy having 1 to 30 carbons, More preferred is alkyl having 3 to 25 carbon atoms or alkoxy having 3 to 25 carbon atoms. Among the diamines represented by the general formula (IX), the diamines represented by the general formulas (B1) to (B3) are more preferable, and the diamines represented by the structural formulas (B1-1) to (B3-1). Is particularly preferred.

  Examples of the side chain diamine represented by the general formula (IX) include diamines represented by the following general formulas (IX-10) to (IX-15).

In the general formulas (IX-10) to (IX-13), R ²⁰ is preferably an alkyl having 4 to 30 carbon atoms, and more preferably an alkyl having 6 to 25 carbon atoms. In the general formulas (IX-14) and (IX-15), R ²¹ is preferably an alkyl having 6 to 30 carbon atoms, more preferably an alkyl having 8 to 25 carbon atoms.

  Examples of the side chain diamine represented by the general formula (IX) include diamines represented by the following general formulas (IX-16) to (IX-36).

The general formulas (IX-16), (IX-17), (IX-20), (IX-22), (IX-23), (IX-26), (IX-28), (IX-29) In (IX-34) and (IX-35), R ²² is preferably alkyl having 1 to 30 carbons, alkoxy having 1 to 30 carbons, alkyl having 3 to 25 carbons or alkoxy having 3 to 25 carbons. Is more preferable.
Formulas (IX-18), (IX-19), (IX-21), (IX-24), (IX-25), (IX-27), (IX-30) to (IX-33) and (IX-36) in, R ²³ is -H, -F, alkyl having 1 to 30 carbon atoms, alkoxy having 1 to 30 carbon atoms, -CN, are -OCH ₂ F, -OCHF ₂ or -OCF ₃ preferably Further, alkyl having 3 to 25 carbon atoms or alkoxy having 3 to 25 carbon atoms is more preferable. In the general formulas (IX-31) and (IX-32), A ⁹ represents alkylene having 1 to 20 carbon atoms.

  Examples of the side chain diamine represented by the general formula (IX) include diamines represented by the following structural formulas (IX-37) to (IX-46).

The side chain type diamine represented by the general formula (IX) is represented by the general formulas (IX-1) to (IX-9).
The diamine represented by general formula (IX-2) or (IX-4) is more preferable.

In the side chain diamine represented by the general formula (X), one of two “NH ₂ —Ph—A ⁶ —O—” is bonded to the 3-position of the steroid nucleus and the other is bonded to the 6-position. It is preferable. Further, the two amino groups bonded to the two phenyl groups are preferably bonded to the meta position or the para position with respect to the bonding position of A ⁶ .

  Examples of the side chain diamine represented by the general formula (X) include diamines represented by the following structural formulas (X-1) to (X-4).

In the side chain type diamine represented by the general formula (XI), two “NH ₂ — (R ¹⁴ —) Ph—A ⁶ —O—” are bonded to the carbon of phenyl, respectively, It is preferable that it is couple | bonded with the meta position or the para position with respect to the carbon in the phenyl which has couple | bonded. Further, the two amino groups bonded to the two phenyl groups are preferably bonded to the meta position or the para position with respect to the bonding position of A ⁶ .

  Examples of the side chain diamine represented by the general formula (XI) include diamines represented by the following structural formulas (XI-1) to (XI-8).

In the side chain diamine represented by the general formula (XII), it is preferable that two amino groups bonded to two phenyl groups are bonded to A ^{7 in} a meta position or a para position.

（−Ｙ⁴は炭素数１から３０のアルキル、

、または

であり、−Ｙ⁵および−Ｙ⁶はそれぞれ独立して炭素数１から３０のアルキルであり、Ｘ²は−ＣＨ₂−又は−Ｏ−を表わす。） Examples of the side chain diamine represented by the general formula (XII) include diamines represented by the following general formula (XII-A).

(—Y ⁴ is alkyl having 1 to 30 carbon atoms,

Or

In and, -Y ⁵ and -Y ⁶ are each independently alkyl having 1 to 30 carbon atoms, X ² is -CH ₂ - represents or -O-. )

  Moreover, as a side chain type diamine represented by the said general formula (XII), the diamine represented by the following general formula (XII-1)-(XII-9) is mentioned, for example.

In the general formulas (XII-1) and (XII-2), R ²⁴ is preferably —H or an alkyl group having 1 to 30 carbon atoms, and the general formulas (XII-4) and (XII-5) Among them, R ²⁵ is preferably —H or an alkyl group having 1 to 30 carbon atoms. In the general formula (XII-3), R ²⁴ is preferably —H or an alkyl group having 1 to 30 carbon atoms. In the general formulas (XII-6) to (XII-9), R ²⁵ is It is preferable that it is -H or a C1-C20 alkyl group.

  As the diamine represented by the general formula (XII), for example, diamines represented by the following structural formulas (XII-2-1), (XII-4-1) and (XII-7-1) are preferably used.

In the side chain diamine represented by the general formula (XIII), it is preferable that two amino groups bonded to two phenyl groups are bonded to A ^{7 in} a meta position or a para position.

  Examples of the side chain diamine represented by the general formula (XIII) include diamines represented by the following general formulas (XIII-1) to (XIII-3).

In the general formula, R ²⁶ is preferably an alkyl group having 6 to 20 carbon atoms, and R ²⁷ is preferably —H or an alkyl group having 1 to 10 carbon atoms.

  The molar ratio of the side chain diamine in the diamine is preferably 1 to 90% in TN and VA from the viewpoint of obtaining an appropriate pretilt angle when a liquid crystal display device is obtained, and is 5 to 80%. More preferably.

  The diamine or a derivative thereof, as a diamine other than the diamine represented by the general formula (I), a naphthalene diamine having a naphthalene structure, a fluorene diamine having a fluorene structure, or a siloxane diamine having a siloxane bond, Alternatively, a diamine having a side chain structure other than the side chain structures represented by the general formulas (IX) to (XIII) may be further included.

  For example, examples of the siloxane diamine include diamines represented by the following general formula (XV).

In the general formula (XV), R ²⁸ and R ²⁹ independently represent alkyl having 1 to 3 carbon atoms or phenyl, and A ¹⁰ independently represents methylene, phenylene, or alkyl-substituted phenylene. i represents an integer of 1 to 6, and j represents an integer of 1 to 10.

  Examples of the diamine represented by the general formula (XV) include diamines represented by the following structural formulas (XV-1) to (XV-7).

  Furthermore, although it does not specifically limit as said other diamine, For example, the diamine represented by the following general formula (1 ')-(8') is mentioned.

In the general formula, R ³⁰ independently represents an alkyl group having 3 to 30 carbon atoms, and in the general formulas (4 ′), (6 ′) and (8 ′), R ³¹ has 3 to 30 carbon atoms. Represents an alkyl group.

Examples of the diamine derivative include a silylated diamine compound obtained by silylating a diamine.
Examples of silylating agents used for silylation of diamines include trimethylchlorosilane, trimethylbromosilane, trimethyliodosilane, triethylchlorosilane, triethylbromosilane, tripropylchlorosilane, tributylchlorosilane, trihexylchlorosilane, dimethylpropylchlorosilane, and dimethylpropylchlorosilane. , Trialkyl halogenated silanes such as dimethyloctylchlorosilane, dimethyloctadecylchlorosilane, t-butyldimethylchlorosilane; vinyl group-containing halogenated silanes such as dimethylvinylchlorosilane; dimethylphenylchlorosilane, diphenylmethylchlorosilane, dimethylphenylchlorosilane, diphenylmethylchlorosilane, Fe, such as methylphenylvinylchlorosilane Group containing halogenated silanes; halogenated alkyl group containing silanes such as chloromethyldimethylchlorosilane, 3-chloropropyldimethylchlorosilane, dichloromethyldimethylchlorosilane; alkoxy groups containing trimethoxychlorosilane, triethoxychlorosilane, dimethoxymethylchlorosilane, etc. Halogenated silanes; alkyl group-containing dihalogenated silanes such as dimethyldichlorosilane, diethyldichlorosilane, dipropyldichlorosilane, dibutyldichlorosilane, and dihexyldichlorosilane; disilanes such as hexamethyldisilane, hexaethyldisilane, and hexaphenyldisilane; bis ( Trimethylsilyl) acetamide, bis (triethylsilyl) acetamide, bis (triphenylsilyl) acetamide, etc. Silylated acetamide; and disilazane such as hexamethyldisilazane.
Examples of a method for obtaining a silylated diamine compound by silylating a diamine include the method described in JP-A-1-217420.

The other diamines are not limited to the diamines described above, and various other types of diamines can be used as long as the object of the present invention is achieved. Needless to say.

  A part of the diamine may be replaced with a monoamine. Replacing a part of the diamine with a monoamine causes the termination of the polymerization reaction that produces the polyamic acid or its derivative and suppresses the progress of the further reaction, so the molecular weight of the resulting polyamic acid or its derivative can be easily controlled. From the viewpoint of Although the ratio of the monoamine with respect to diamine should just be a range which does not impair the effect of this invention, it is preferable that it is 10 mol% or less of all the amines as a standard.

  Preferably, tetracarboxylic dianhydride is used as the tetracarboxylic acid or derivative thereof. The tetracarboxylic dianhydride may be one kind or two or more kinds. From the viewpoint of making the polyamic acid or derivative thereof in the present invention soluble in a solvent, it is preferable to appropriately select the tetracarboxylic dianhydride. Examples of the tetracarboxylic dianhydride include aromatic tetracarboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides, and alicyclic tetracarboxylic dianhydrides. The tetracarboxylic dianhydride may include a silsesquioxane dianhydride derivative.

  Examples of the aromatic tetracarboxylic dianhydride include compounds represented by the following structural formulas (1) to (13).

  The aromatic tetracarboxylic dianhydride is preferably a compound represented by the following structural formulas (1), (2), (5), (6) and (7). More preferred is pyromellitic dianhydride.

  Examples of the aliphatic tetracarboxylic dianhydride and the alicyclic tetracarboxylic dianhydride include compounds represented by the following structural formulas (14) to (62).

  The aliphatic tetracarboxylic dianhydride and the alicyclic tetracarboxylic dianhydride are preferably compounds represented by the structural formulas (14) to (29) and (60). It is more preferable that it is 1,2,3,4-cyclobutanetetracarboxylic dianhydride represented by (14).

  In addition, the aliphatic tetracarboxylic dianhydride and the alicyclic tetracarboxylic dianhydride are the structural formulas (19) and (20) from the viewpoint that the polyamic acid or a derivative thereof in the present invention is a polyimide soluble in a solvent. ), (27) to (29), and (60).

Examples of the silsesquioxane dianhydride derivative include compounds represented by the following structural formula (i).

Further, the tetracarboxylic dianhydride may contain a tetracarboxylic dianhydride having a side chain structure. The tetracarboxylic dianhydride having a side chain structure can increase the pretilt angle in the liquid crystal display element. Examples of the tetracarboxylic dianhydride having a side chain structure include compounds having a steroid skeleton represented by the following structural formulas (63) and (64).

  Examples of the tetracarboxylic acid derivative include dicarboxylic acid diester compounds obtained by esterifying a tetracarboxylic dianhydride represented by the following general formula (10000).

In the Formula 10000, Y ¹⁰⁰ represents an alkyl having 1 to 4 carbon atoms.

Examples of monohydric alcohols and monohydric alcohol derivatives that esterify tetracarboxylic dianhydride include methanol, ethanol, propanol, and butanol. A method of obtaining a dicarboxylic acid diester compound by esterifying tetracarboxylic dianhydride is carried out according to the method described in JP-A-61-72022.
As a method for obtaining a polyimide derivative from a dicarboxylic acid diester compound and a diamine, a method using carbodiimide as a condensing agent (Japanese Patent Laid-Open No. Sho 61-72022), a method using a carbonic acid diester (Japanese Patent Laid-Open No. Sho 62-72724), a phosphorus system Examples thereof include a method using a compound (Japanese Patent Laid-Open No. 2002-356554), and a method of heating in a phenol solvent (Japanese Patent Laid-Open No. 53-124596).

The tetracarboxylic dianhydride includes the aromatic tetracarboxylic dianhydride and one or both of an aliphatic tetracarboxylic dianhydride and an alicyclic tetracarboxylic dianhydride. This is preferable from the viewpoint of reducing the residual voltage.

  The tetracarboxylic dianhydride includes various other forms of tetracarboxylic dianhydride, and is not limited to the tetracarboxylic dianhydride described above. As the tetracarboxylic dianhydride, various other forms of tetracarboxylic dianhydride can be used within the scope of achieving the object of the present invention.

  A part of the tetracarboxylic dianhydride may be replaced with a carboxylic anhydride. Replacing a part of the tetracarboxylic dianhydride with a carboxylic acid anhydride causes termination of the polymerization reaction to produce the polyamic acid or a derivative thereof, and suppresses further progress of the reaction. This is preferable from the viewpoint of easily controlling the molecular weight of the derivative. The ratio of the carboxylic anhydride to the tetracarboxylic dianhydride may be in a range that does not impair the effects of the present invention, but it is preferably 10 mol% or less of the tetracarboxylic dianhydride as a guide.

More specific examples of the combination of the diamine or derivative thereof and the tetracarboxylic acid or derivative thereof described above are preferable.
(1) One or more diamines represented by the structural formulas (I-1) to (I-5), and the structural formulas (A1), (B1-1), (B2-1). , (B3-1), (C1), (C2), (C3), (D1), (D2), (D3), (D4), (XII-2-1), (XII-4-1) And one or both of the tetracarboxylic dianhydrides represented by the structural formulas (1) and (14), wherein the tetracarboxylic acid or a derivative thereof is one or both of the diamines represented by (XII-7-1) A combination including
(2) The diamine or derivative thereof is one or more diamines represented by the structural formulas (I-1) to (I-5), and the structural formulas (A1), (C1), (C2), (C3). And one or both of the tetracarboxylic dianhydrides represented by the structural formulas (1) and (14), wherein the tetracarboxylic acid or a derivative thereof is one or both of the diamines represented by (D1) and (D2) A combination including A preferred application of this combination is an IPS liquid crystal display element and a TN liquid crystal display element.
(3) In the above (2), the diamine or derivative thereof is one or more diamines represented by the structural formulas (I-1) to (I-5), the structural formulas (A1), (D1) and ( A combination containing one or both of the tetracarboxylic dianhydrides represented by the structural formulas (1) and (14), including one or more diamines represented by D2). A preferred application of this combination is an IPS liquid crystal display element.
(4) One or more diamines represented by the structural formulas (I-1) to (I-5) and the structural formulas (D2), (D3), (D4), (XII- 2-1), one or more diamines represented by (XII-4-1) and (XII-7-1), wherein the tetracarboxylic acid or a derivative thereof is represented by the structural formulas (1) and (14). A combination comprising one or both of the tetracarboxylic dianhydrides represented. A preferred application of this combination is a TN liquid crystal display element.
(5) In the above (4), the diamine or derivative thereof is one or more diamines represented by the structural formulas (I-1) to (I-5), the structural formula (XII-2-1), ( XII-4-1) and one or more diamines represented by (XII-7-1), wherein the tetracarboxylic acid or a derivative thereof is represented by the structural formulas (1) and (14). A combination comprising one or both anhydrides. A preferred application of this combination is a TN liquid crystal display element.
(6) One or more diamines represented by the structural formulas (I-1) to (I-5) and the structural formulas (B1-1), (B2-1), (B3- 1) and (D1
And a combination of one or more tetracarboxylic dianhydrides represented by the structural formulas (1), (14) and (i). A preferred application of this combination is a VA liquid crystal display element.
(7) In the above (6), the diamine or derivative thereof is one or more diamines represented by the structural formulas (I-1) to (I-5) and the diamine represented by the structural formula (B1-1). And the tetracarboxylic acid or derivative thereof includes a tetracarboxylic dianhydride represented by the structural formula (14). A preferred application of this combination is a VA liquid crystal display element.
Moreover, it is preferable to employ the combination of (1) to (7) from the viewpoint of reducing the residual voltage of the liquid crystal display element.

The weight average molecular weight of the polyamic acid or derivative thereof is not particularly limited, but when used as a component of a liquid crystal aligning agent, it does not evaporate in the step of firing the liquid crystal aligning film, and obtains preferable physical properties as a component of the liquid crystal aligning agent. From the viewpoint, it is preferably 5 × 10 ³ or more, and more preferably 1 × 10 ⁴ or more. The weight average molecular weight is preferably 1 × 10 ⁶ or less from the viewpoint of easy handling as a liquid crystal aligning agent such as viscosity.

  The weight average molecular weight of the polyamic acid or derivative thereof is measured by gel permeation chromatography (GPC). For example, the obtained polyamic acid or derivative thereof is diluted with dimethylformamide (DMF) so that the concentration of the polyamic acid or derivative thereof is about 1% by weight, and Chromatopack C-R7A (manufactured by Shimadzu Corporation) is used. It is determined by gel permeation chromatographic analysis (GPC) method using DMF as a developing solvent and converted to polystyrene. Furthermore, from the viewpoint of improving the accuracy of GPC measurement, a developing solvent in which an inorganic acid such as phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid or the like or an inorganic salt such as lithium bromide or lithium chloride is dissolved in a DMF solvent may be prepared and used. .

  The polyamic acid or a derivative thereof can be produced using a known method. For example, the diamine is charged into a reaction vessel equipped with a raw material inlet, a nitrogen inlet, a thermometer, a stirrer, and a condenser, and a desired amount of monoamine is charged as necessary.

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

  A solution of polyamic acid can be suitably obtained by reacting at a temperature of 0 to 70 ° C. for 1 to 48 hours under stirring. Moreover, polyamic acid with small molecular weight can also be obtained by heating and raising reaction temperature (for example, 50-80 degreeC). The produced polyamic acid is obtained by precipitating with a large amount of a poor solvent and completely separating the solid and the solvent by filtration or the like.

  Soluble polyimide, which is a polyamic acid derivative, is usually prepared by removing a polyamic acid solution from acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride as dehydrating agents, and triethylamine, pyridine, collidine, etc. as dehydrating ring closure catalysts. It can obtain by imidating at 20-150 degreeC with the tertiary amine of.

Or, polyamic acid is precipitated from a solution of polyamic acid using a large amount of poor solvent (alcohol solvent or glycol solvent such as methanol, ethanol, isopropanol),
The precipitated polyamic acid can also be obtained by imidization reaction at a temperature of 20 to 150 ° C. in a solvent such as toluene and xylene together with the same dehydrating agent and dehydrating ring-closing catalyst.

  In the imidization reaction, the ratio of the dehydrating agent to the dehydrating ring-closing catalyst is preferably 0.1 to 10 (molar ratio). The total amount of both is preferably 1.5 to 10 times the total molar amount of acid dianhydride contained in the tetracarboxylic dianhydride used. By adjusting the dehydrating agent, catalyst amount, reaction temperature and reaction time of this chemical imidization, the degree of imidization can be controlled to obtain a partial polyimide.

  Further, when a part of the tetracarboxylic dianhydride is replaced with an organic dicarboxylic acid, a polyamic acid-polyamide copolymer can be obtained. Here, the ratio of the organic dicarboxylic acid to the tetracarboxylic dianhydride may be in a range that does not impair the effects of the present invention, but as a guide, it should be 10 mol% or less of the tetracarboxylic dianhydride. preferable.

  Furthermore, polyamideimide can be produced by chemically imidizing the polyamic acid-polyamide copolymer.

  The polyamic acid or derivative thereof can be identified by analyzing by IR or NMR. Furthermore, after decomposing solid polyamic acid or its derivatives with an aqueous solution of strong alkali such as KOH or NaOH, the monomer used is identified by extracting with an organic solvent and analyzing by GC, HPLC or GC-MS. can do.

  The obtained polyamic acid or derivative thereof can be used after being diluted with a solvent in order to adjust to a desired viscosity.

  The obtained polyamic acid or derivative thereof can be separated from the solvent and re-dissolved in the solvent described later together with the epoxy compound described later and used as a liquid crystal aligning agent, or the epoxy compound without being separated from the solvent. Can also be used as a liquid crystal aligning agent.

  The polyamic acid or a derivative thereof can appropriately adjust the pretilt angle in the liquid crystal display device by using a diamine having a side chain structure such as the side chain diamine or tetracarboxylic dianhydride. It can be applied to various types of liquid crystal display elements. As the pretilt angle, in the case of a VA liquid crystal display element, a large pretilt angle of about 80 to 90 °, and in the case of an OCB liquid crystal display element, a pretilt angle of about 7 to 20 ° is used. In the case of an STN type liquid crystal display element, a pretilt angle of about 3 to 10 ° is often required, and in the case of an IPS type liquid crystal display element, a small pretilt angle of about 0 to 3 ° is often required.

  The characteristic expressed by the monomer of polyamic acid or its derivative like the above-mentioned pretilt angle can be obtained by producing polyamic acid or its derivative using a monomer that provides such characteristic. The characteristics of the monomer can be obtained from one kind of polyamic acid obtained by using a plurality of types of monomers that provide such characteristics, or derivatives thereof, and two types of characteristics that can be obtained by using a plurality of types of monomers that provide such characteristics. It can be obtained from more than one polyamic acid or derivative thereof.

  It is preferable from the viewpoint of imparting preferable characteristics as the liquid crystal aligning agent of the present invention that two or more kinds of polyamic acids or derivatives thereof different in part or all of the monomers are contained in the liquid crystal aligning agent. The mixing ratio of two or more kinds of polyamic acids or derivatives thereof may be such that desired characteristics according to the use of the liquid crystal aligning agent can be obtained.

  More specifically, by appropriately selecting the type of diamine or derivative thereof, tetracarboxylic acid or derivative thereof, and a combination thereof, further reduction in residual voltage required for the liquid crystal aligning agent of the present invention and suitable Desired characteristics such as a pretilt angle can be imparted and improved.

  The epoxy compound is a compound having two or more epoxy groups. The epoxy compound may be one type or two or more types. An epoxy compound is used by the kind and content which form the solution of an epoxy compound and the said polyamic acid or its derivative (s) in a liquid crystal aligning agent. The epoxy resin means a resin having an epoxy group.

  Examples of the epoxy compound include glycidyl ether, glycidyl ester, glycidyl amine, epoxy group-containing acrylic resin, glycidyl amide, glycidyl isocyanurate, chain aliphatic epoxy compound, and cyclic aliphatic epoxy compound.

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

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

  Examples of the glycidylamine include polyglycidylamine compounds and glycidylamine type epoxy resins.

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

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

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

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

Examples of the bisphenol A type epoxy compound include 828, 1001, 1002, 1003, 1004, 1007, 1010 (all manufactured by Japan Epoxy Resin), Epototo YD-128 (manufactured by Tohto Kasei Co., Ltd.), DER-331, and DER-332. , DER-3
24 (all manufactured by Dow Chemical Company), Epicron 840, Epicron 850, Epicron 1050 (all manufactured by Dainippon Ink), Epomic R-140, Epomic R-301, and Epomic R-304 (all manufactured by Mitsui Chemicals) Is mentioned.

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

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

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

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

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

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

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

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

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

Examples of the aromatic polyglycidyl ether compound include hydroquinone diglycidyl ether (the following structural formula 101), catechol diglycidyl ether (the following structural formula 102), resorcinol diglycidyl ether (the following structural formula 103), 2- [4- (2 , 3-epoxypropoxy) phenyl] -2- [4- [1,1-bis [4-([2,3-epoxypropoxy] phenyl)] ethyl] phenyl] propane (Structural Formula 104 below), Tris (4 -Glycidyloxyphenyl) methane (the following structural formula 105), 1031S, 1032H60 (all manufactured by Japan Epoxy Resin), TACTIX-742 (manufactured by Dow Chemical), Denacol EX-201 (manufactured by Nagase ChemteX), DPPN- 503, DPPN-502H, DPPN-50 H, NC6000 (all manufactured by Nippon Kayaku Co.), Techmore VG3101L (manufactured by Mitsui Chemicals, Inc.), compounds represented by the following structural formula 106, and compounds represented by the following structural formula 107.

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

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

  Examples of the aliphatic polyglycidyl ether compound include ethylene glycol diglycidyl ether (the following structural formula 108), diethylene glycol diglycidyl ether (the following structural formula 109), polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether (the following structural formula 110). ), Tripropylene glycol diglycidyl ether (the following structural formula 111), polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether (the following structural formula 112), 1,4-butanediol diglycidyl ether (the following structural formula 113), 1,6-hexanediol diglycidyl ether (the following structural formula 114), dibromoneopentyl glycol diglycidyl ether (the following structural formula 115), Denaco EX-810, Denacol EX-851, Denacol EX-8301, Denacol EX-911, Denacol EX-920, Denacol EX-931, Denacol EX-211, Denacol EX-212, Denacol EX-313 (all Nagase ChemteX Co., Ltd.), DD-503 (Asahi Denka Co., Ltd.), Rica Resin W-100 (Nippon Nippon Chemical Co., Ltd.), 1,3,5,6-tetraglycidyl-2,4-hexanediol (the following structural formula 116), glycerin poly Glycidyl ether, sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, Denacol EX-313, Denacol EX-611, Denacol EX-321, and Denacol EX-411 (all Nagaseke Made-Tex), and the like.

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

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

  Examples of the diglycidyl ester compound include diglycidyl terephthalate (the following structural formula 117), diglycidyl phthalate (the following structural formula 118), bis (2-methyloxiranylmethyl) phthalate (the following structural formula 119), and diglycidyl hexa. Examples include hydrophthalate (the following structural formula 120), a compound represented by the following structural formula 121, a compound represented by the following structural formula 122, and a compound represented by the following structural formula 123.

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

Examples of the polyglycidylamine compound include N, N-diglycidylaniline (the following structural formula 124), N, N-diglycidyl-o-toluidine (the following structural formula 125), N, N-diglycidyl-m-toluidine (the following). Structural formula 126), N, N-diglycidyl-2,4,6-tribromoaniline (the following structural formula 127), 3- (N, N-diglycidyl) aminopropyltrimethoxysilane (the following structural formula 128), N, N, O-triglycidyl-p-aminophenol (the following structural formula 129), N, N, O-triglycidyl-m-aminophenol (the following structural formula 130), N, N, N ′, N′-tetraglycidyl -4,4'-diaminodiphenylmethane (the following structural formula 131), N, N, N ', N'-tetraglycidyl-m-xylylenediamine (TETR) DX (Mitsubishi Gas Chemical), structural formula 132 below, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (TETRAD-C (Mitsubishi Gas Chemical), structural formula 133 below), 1,4 -Bis (N, N-diglycidylaminomethyl) cyclohexane (the following structural formula 134), 1,3-bis (N, N-diglycidylamino) cyclohexane (the following structural formula 135), 1,4-bis (N, N-diglycidylamino) cyclohexane (the following structural formula 136), 1,3-bis (N, N-diglycidylamino) benzene (the following structural formula 137), 1,4-bis (N, N-diglycidylamino) Benzene (the following structural formula 138), 2,6-bis (N, N-diglycidylaminomethyl) bicyclo [2.2.1] heptane (the following structural formula 139), N, N, N ′, N′-te Laglycidyl-4,4′-diaminodicyclohexylmethane (the following structural formula 140), 2,2′-dimethyl- (N, N, N ′, N′-tetraglycidyl) -4,4′-diaminobiphenyl (the following structure) Formula 141), N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenyl ether (Structure 142 below), 1,3,5-tris (4- (N, N-diglycidyl) aminophenoxy ) Benzene (the following structural formula 143), 2,4,4′-tris (N, N-diglycidylamino) diphenyl ether (the following structural formula 144), tris (4- (N, N-diglycidyl) aminophenyl) methane ( The following structural formula 145), 3,4,3 ′, 4′-tetrakis (N, N-diglycidylamino) biphenyl (the following structural formula 146), 3,4,3 ′, 4′-tetrakis (N, N— Glycidyl amino) diphenyl ether (Formula 147), a compound represented by the following structural formula 148, and compounds represented by the following structural formula 149.

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

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

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

  Examples of the glycidyl isocyanurate include 1,3,5-triglycidyl-1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione (the following structural formula 150), 1,3. -Diglycidyl-5-allyl-1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione (the following structural formula 151), and glycidyl isocyanurate type epoxy resin.

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

  Examples of the cycloaliphatic epoxy compound include 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate (Celoxide 2021 (manufactured by Daicel Chemical Industries, Ltd.), the following structural formula 152), 2 -Methyl-3,4-epoxycyclohexylmethyl-2'-methyl-3 ', 4'-epoxycyclohexylcarboxylate (the following structural formula 153), 2,3-epoxycyclopentane-2', 3'-epoxycyclopentane Ether (the following structural formula 154), ε-caprolactone-modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 1,2: 8,9-diepoxy limonene (Celoxide 3000 (Daicel Chemical Industries ( Co., Ltd.), the following structural formula 155), the following structural formula 56, CY-175, CY-177, CY-179 (all manufactured by CIBA-GEIGY), EHPD-3150 (manufactured by Daicel Chemical Industries, Ltd.), and cyclic aliphatic epoxy resins. It is done.

The epoxy compound is preferably one or more of a polyglycidylamine compound, a bisphenol A novolac epoxy compound, a cresol novolac epoxy compound, and a cyclic aliphatic epoxy compound, and N, N, N ′, N′-tetra Glycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, trade name “Techmore VG3101L 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate, N-phenylmaleimide-glycidyl methacrylate copolymer, N, N, O-triglycidyl-p-aminophenol, bisphenol A novolak Type epoxy compounds and It is preferably one or more of sol novolak type epoxy compounds.

  The liquid crystal aligning agent of this invention may further contain components other than the polyamic acid mentioned above or its derivative (s), and an epoxy compound. Examples of such additional components include solvents and various additives contained in ordinary liquid crystal aligning agents.

  The said solvent contains the solvent normally used in the manufacturing process and use of polymer components, such as a polyamic acid, a soluble polyimide, and a polyamideimide, and can be suitably selected according to the intended purpose. For example, the solvent can be used from the viewpoints of adjusting physical properties such as the viscosity of the liquid crystal aligning agent, ease of handling, and simplification of the process. The solvent may be one type or two or more types. Examples of the solvent include an aprotic polar organic solvent that is easily soluble in polyamic acid or a derivative thereof, and a coating property improving solvent for improving coating property by changing the surface tension. A mixed solvent containing these is preferable.

  Examples of the aprotic polar organic solvent include N-methyl-2-pyrrolidone, N, N′-dimethylimidazolidinone, N-methylcaprolactam, N, N-dimethylpropionamide, N, N-dimethylacetamide, and dimethyl. Examples include sulfoxide, N, N-dimethylformamide, N, N-diethylformamide, N, N-diethylacetamide, N, N, N ′, N′-tetramethylurea, γ-butyrolactone, and γ-valerolactone. The aprotic polar organic solvent is preferably at least one selected from N-methyl-2-pyrrolidone, N, N′-dimethylimidazolidinone, γ-butyrolactone, and γ-valerolactone.

  Examples of the coating property improving solvent include alkyl lactate, 3-methyl-3-methoxybutanol, tetralin, isophorone, ethylene glycol monoalkyl ether such as ethylene glycol monobutyl ether, diethylene glycol monoalkyl ether such as diethylene glycol monoethyl ether, ethylene glycol Monoalkyl or phenyl acetate, propylene glycol monoalkyl ether such as triethylene glycol monoalkyl ether, propylene glycol monobutyl ether, dialkyl malonate such as diethyl malonate, dipropylene glycol monoalkyl ether such as dipropylene glycol monomethyl ether, and the like Examples include ester compounds such as acetates. The coating property improving solvent is preferably at least one selected from ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, and dipropylene glycol monomethyl ether.

  The types and ratios of the aprotic polar solvent and the coatability improving solvent can be appropriately set in consideration of the printability, coatability, solubility, storage stability, and the like of the liquid crystal aligning agent. The aprotic polar solvent is relatively superior in solubility and storage stability to the applicability improving solvent, and the applicability improving solvent tends to be excellent in printability and applicability.

  The additive may be a component used for the purpose of improving specific properties of the liquid crystal aligning agent, and may be one kind or two or more kinds. Examples of the additive include a high molecular compound and a low molecular compound other than polyamic acid or a derivative thereof used according to each purpose.

  The polymer compound is preferably a polymer compound that is soluble in an organic solvent from the viewpoint of controlling the electrical properties and orientation of the liquid crystal alignment film to be formed. Examples of such a polymer compound include polyamide, polyurethane, polyurea, polyester, polyepoxide, polyester polyol, silicone-modified polyurethane, and silicone-modified polyester.

  Examples of the low molecular weight compound include surfactants, antistatic agents, silane coupling agents, titanium-based coupling agents, and imidization catalysts. The surfactant is preferable from the viewpoint of improving the coating property of the liquid crystal aligning agent. The antistatic agent is preferable from the viewpoint of improving the antistatic property of the liquid crystal aligning agent and the liquid crystal alignment film. The silane coupling agent and the titanium-based coupling agent agent are preferable from the viewpoint of improving the adhesion of the liquid crystal alignment film to the substrate and the rubbing resistance. The imidization catalyst is preferable from the viewpoint of allowing imidization to proceed at a low temperature in the formation of the liquid crystal alignment film.

  Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-aminopropylmethyl. Trimethoxysilane, paraaminophenyltrimethoxysilane, paraaminophenyltriethoxysilane, metaaminophenyltrimethoxysilane, metaaminophenyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycid Xylpropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloro Propyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propylamine, and N , N′-bis [3- (trimethoxysilyl) propyl] ethylenediamine.

  Examples of the imidization catalyst include aliphatic amines such as trimethylamine, triethylamine, tripropylamine, and tributylamine; aromatic amines such as N, N-dimethylaniline, N, N-diethylaniline, methyl-substituted aniline, and hydroxy-substituted aniline. Cyclic amines such as pyridine, methyl substituted pyridine, hydroxy substituted pyridine, quinoline, methyl substituted quinoline, hydroxy substituted quinoline, isoquinoline, methyl substituted isoquinoline, hydroxy substituted isoquinoline, imidazole, methyl substituted imidazole, hydroxy substituted imidazole . The imidization catalyst is preferably at least one selected from N, N-dimethylaniline, o-, m-, p-hydroxyaniline, o-, m-, p-hydroxypyridine, and isoquinoline.

  The addition amount of the silane coupling agent is usually 0 to 30 parts by weight and preferably 0.05 to 20 parts by weight with respect to 100 parts by weight of the polyamic acid or derivative thereof.

  The amount of the imidation catalyst added is usually 0 to 5 equivalents, preferably 0.05 to 3 equivalents, relative to the carbonyl group of the polyamic acid or derivative thereof.

  The addition amount of other additives varies depending on the application, but is usually 0 to 30 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of polyamic acid or a derivative thereof. .

The content rate of the polyamic acid or its derivative in the liquid crystal aligning agent of this invention may be selected also by the coating method to the board | substrate of a liquid crystal aligning agent. For example, if it is a liquid crystal aligning agent used in a printing machine (including an offset printing machine and an ink jet printing machine, hereinafter may be abbreviated as “printing machine”) used in a manufacturing process of a normal liquid crystal display element, The content of the polyamic acid or its derivative is preferably 0.5 to 30% by weight, more preferably 1 to 15% by weight, but it is appropriately adjusted in relation to the viscosity (described later) of the liquid crystal aligning agent. The

  The viscosity of the liquid crystal aligning agent of the present invention varies depending on the coating method, the concentration of the polyamic acid or derivative thereof, the type of polyamic acid or derivative thereof used, and the type and ratio of the solvent. For example, in the case of application by a printing press, the viscosity of the liquid crystal aligning agent is preferably 5 to 100 mPa · s, and more preferably 10 to 80 mPa · s. When the viscosity of the liquid crystal aligning agent is smaller than 5 mPa · s, it is difficult to obtain a sufficient film thickness of the liquid crystal aligning film, and when it exceeds 100 mPa · s, printing unevenness may be increased. In the case of application by spin coating, the viscosity of the liquid crystal aligning agent is preferably 5 to 200 mPa · s, more preferably 10 to 100 mPa · s.

  The viscosity of the liquid crystal aligning agent is measured by a rotational viscosity measuring method, and is measured using a rotational viscometer (TVE-20L type manufactured by Toki Sangyo Co., Ltd.) (measurement temperature: 25 ° C.).

  The liquid crystal alignment film of the present invention is formed by baking the film of the liquid crystal aligning agent of the present invention described above. Formation and baking of the liquid crystal aligning agent film can be performed by a usual method in a photoresist.

  The liquid crystal alignment film is, for example, a liquid crystal display element substrate or a measurement substrate such as calcium fluoride or silicon applied to the liquid crystal alignment agent of the present invention. Preferably it can form by heating at 180-280 degreeC. Here, the film thickness of the liquid crystal alignment film is preferably 10 to 300 nm, and more preferably 30 to 100 nm. In addition, the liquid crystal alignment film is preferably rubbed when it is used for a horizontal electric field type liquid crystal display element such as an IPS liquid crystal display element.

  The film thickness of the liquid crystal alignment film can be adjusted by the viscosity of the liquid crystal aligning agent and the application method of the liquid crystal aligning agent. The film thickness of the liquid crystal alignment film can be measured by a known film thickness measuring device such as a step meter or an ellipsometer. Furthermore, the components in the liquid crystal alignment film can be analyzed using a normal analysis means such as IR or MS after performing a treatment such as hydrolysis as necessary. For example, “Performance improvement of polybenzoxazine by alloying with polyimide: effect of preparation method on the properties” (Tsutomu Takeichi et al., Polymer, 2005, 46, p.4909-4916).

  The liquid crystal display element of the present invention includes a pair of opposed substrates, electrodes formed on one or both of the opposed surfaces of the pair of substrates, and the pair of substrates facing each other. And a liquid crystal layer formed between the pair of substrates.

  The pair of substrates with electrodes arranged opposite to each other is preferably a transparent substrate (for example, a glass substrate).

An electrode is provided on the surface of at least one or both of the pair of substrates according to the form of the liquid crystal display element. The electrode is not particularly limited as long as it is an electrode formed on one surface of the substrate. Examples of such electrodes include ITO and metal vapor deposition films. The electrode may be formed on the entire surface of the substrate, or may be formed in a predetermined shape that is patterned, for example. Further, the electrode may be provided on only one of the pair of substrates, or may be provided on both. For example, the liquid crystal alignment film of the present invention is formed on the surface of the substrate on which the electrode is not provided, and the liquid crystal alignment film of the present invention is formed on the electrode on the substrate on which the electrode is provided. The formation of the liquid crystal alignment film of the present invention is as described above.

  The liquid crystal layer sandwiched between the pair of substrates includes a liquid crystal composition. Here, the liquid crystal composition is not particularly limited, and either a liquid crystal composition having a positive dielectric anisotropy or a liquid crystal composition having a negative dielectric anisotropy may be used depending on the driving mode. it can.

  Examples of preferable liquid crystal compositions having a positive dielectric anisotropy are disclosed in Japanese Patent No. 3086228, Japanese Patent No. 2635435, Japanese Patent Laid-Open No. 5-501735, Japanese Patent Laid-Open No. 8-157826, Japanese Patent Laid-Open No. 8- No. 231960, JP-A-9-241644 (EP882722A1), JP-A-9-302346 (EP806466A1), JP-A-8-199168 (EP722998A1), JP-A-9-235552, JP-A-9-255556. JP, 9-241643 (EP882711A1), JP 10-204016 (EP844229A1), JP 10-204436, JP 10-231482, JP 2000-087040, JP It is disclosed in 2001-48822 gazette etc. .

  The liquid crystal composition used in the VA liquid crystal display element can be various liquid crystal compositions having negative dielectric anisotropy. Examples of preferred liquid crystal compositions include JP-A-57-141432, JP-A-2-4725, JP-A-4-224858, JP-A-8-40953, JP-A-8-104869, Japanese Laid-Open Patent Publication No. 10-168076, Japanese Laid-Open Patent Publication No. 10-168453, Japanese Laid-Open Patent Publication No. 10-236989, Japanese Laid-Open Patent Publication No. 10-236990, Japanese Laid-Open Patent Publication No. 10-236992, Japanese Laid-Open Patent Publication No. 10-236993, Japanese Laid-open Patent Publication No. -236994, JP-A-10-237000, JP-A-10-237004, JP-A-10-237024, JP-A-10-237035, JP-A-10-237075, JP-A-10-237076 JP, 10-237448, (EP967261A1), JP 10-28787. JP-A-10-287875, JP-A-10-291945, JP-A-11-029581, JP-A-11-080049, JP-A-2000-256307, JP-A-2001-019965, JP 2001-072626 A, JP 2001-192657 A, and the like.

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

  Of course, the liquid crystal display element of the present invention may have other members. For example, in a color display TFT type liquid crystal element using a thin film transistor, a thin film transistor, an insulating film, a protective film, a signal electrode, a pixel electrode, and the like are formed on a first transparent substrate, and the second transparent substrate is formed. A black matrix, a color filter, a planarization film, a pixel electrode, and the like that block light outside the pixel region may be included.

  Further, in a VA liquid crystal display element, in particular, an MVA liquid crystal display element, a minute protrusion called a domain is formed on a first transparent substrate. A spacer may be formed for adjusting the cell gap between the substrates.

The liquid crystal display element of the present invention can be produced by any method. For example, 1) a step of applying a liquid crystal alignment agent on the two transparent substrates, 2) a step of drying the applied liquid crystal alignment agent, 3 ) A step of performing a heat treatment necessary for dehydrating and ring-closing reaction of the dried liquid crystal aligning agent, 4) a step of aligning the obtained liquid crystal alignment film, 5) after bonding the two substrates, It is manufactured by a method including a step of encapsulating a liquid crystal composition in between, or a step of dropping a liquid crystal composition on one substrate and then bonding it to the other substrate.

  As a coating method in the step of applying the liquid crystal aligning agent, 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 also applicable in the present invention.

  Further, as a method of the drying step and the step of performing the heat treatment necessary for the dehydration reaction, 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 also applicable in the present invention. The drying step is preferably performed at a relatively low temperature (50 to 140 ° C.) within a range where the solvent can be evaporated. In general, the heat treatment step is preferably performed at a temperature of about 150 to 300 ° C.

  The alignment treatment for the liquid crystal alignment film is usually a rubbing treatment for IPS liquid crystal display elements, OCB liquid crystal display elements, TN liquid crystal display elements, and STN liquid crystal display elements. In many cases, the VA liquid crystal display element is not subjected to the rubbing treatment.

  Next, an adhesive is applied onto one substrate, and the liquid crystal is injected in a vacuum. In the case of the dropping injection method, the liquid crystal composition is dropped on a substrate before bonding, and then bonded on the other substrate. The liquid crystal display element of the present invention is produced by curing the adhesive used for bonding with heat or ultraviolet rays.

  A polarizing plate (polarizing film), a wave plate, a light scattering film, a driving circuit, and the like may be mounted on the liquid crystal display element of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. The compounds used in the examples are as follows.

<Tetracarboxylic dianhydride>
Compound: pyromellitic dianhydride: PMDA
Compound: 1,2,3,4-cyclobutanetetracarboxylic dianhydride: CBDA

<Diamine>
Compound: 4,4′-diaminodiphenyl sulfide: ASD
Compound: 1,2-bis (4-aminophenyl) thioethane: DDSE
Compound: 1,3-bis (4-aminophenyl) thiopropane: DDSP
Compound: 1,4-bis (4-aminophenyl) thiobutane: DDSB
Compound: 1,5-bis (4-aminophenyl) thiopentane: DDSN
Compound: 4,4′-diaminodiphenylmethane: DDM
Compound: 4,4′-diaminodiphenyl ether: DDE
Compound: 4,4′-diaminodiphenylpropane: DDPr
Compound: N, N′-bis (4-aminophenyl) -N, N′-dimethylethylenediamine: NN2DAMe
Compound: 1,5-bis (4-aminophenyl) oxypentane: DDON

<Epoxy compound>
Compound: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane: TGDDM

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

<1. Synthesis of polyamic acid>
[Synthesis Example 1]
3. Add 4430 g (12.409 mmol) of DDSE and 54.0 g of dehydrated NMP to a 100 mL four-necked flask equipped with a thermometer, stirrer, raw material charging inlet and nitrogen gas inlet, and stir and dissolve in a dry nitrogen stream did. Next, 1.353 g (6.24 mmol) of PMDA, 1.217 g (6.24 mmol) of CBDA, and 15.0 g of dehydrated GBL were added, and the mixture was reacted at room temperature for 30 hours. When the reaction temperature rose during the reaction, the reaction temperature was kept at about 70 ° C. or lower for the reaction. 25.0 g of BC was added to the obtained solution to obtain a polyamic acid solution having a concentration of 6% by weight. This polyamic acid solution is designated as PA1.

[Synthesis Examples 2 to 10]
Polyamic acid solutions PA2 to PA10 were prepared according to Synthesis Example 1 except that tetracarboxylic dianhydride and diamine were changed as shown in Table 1. The results are summarized in Table 1 including Synthesis Example 1.

<2. Production of liquid crystal display element>
[Comparative Example 1]
A liquid crystal aligning agent was obtained by adding a mixed solvent of NMP / BC = 1/1 (weight ratio) to PA1 and diluting the whole so that the concentration of polyamic acid was 4% by weight. Using the obtained liquid crystal aligning agent, a liquid crystal display element was produced as follows.

<Method for Producing Liquid Crystal Display Elements (Examples 1 to 5, Comparative Examples 1 to 10)>
The liquid crystal aligning agent was applied to two glass substrates with an ITO electrode with a spinner to form a film with a thickness of 70 nm. After coating, the film was heated and dried at 80 ° C. for about 5 minutes, and then heat-treated at 210 ° C. for 20 minutes to form a liquid crystal alignment film. Next, the surface of the substrate on which the liquid crystal alignment film was formed was rubbed with a rubbing apparatus to perform the alignment treatment. Thereafter, the liquid crystal alignment film was ultrasonically cleaned in ultrapure water for 5 minutes and then dried in an oven at 120 ° C. for 30 minutes.

  One glass substrate was sprayed with a 7 μm gap material, and the surface on which the liquid crystal alignment film was formed was placed inside so as to face each other so that the rubbing direction was anti-parallel, and then sealed with an epoxy curing agent, and the gap was 7 μm. A parallel cell was produced. The liquid crystal composition shown below was injected into the cell, and the injection port was sealed with a photocuring agent. Next, a heat treatment was performed at 110 ° C. for 30 minutes to manufacture a liquid crystal display element.

[Example 1]
In 4% by weight of the liquid crystal aligning agent obtained in Comparative Example 1, 20 parts by weight of TGDDM was dissolved in 100 parts by weight of polyamic acid to obtain a liquid crystal aligning agent. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 2]
A liquid crystal aligning agent was obtained by adding a mixed solvent of NMP / BC = 1/1 (weight ratio) to PA2 and diluting the whole so that the concentration of polyamic acid was 4% by weight. Using the obtained liquid crystal aligning agent,
A liquid crystal display element was produced as described above.

[Example 2]
In 4% by weight of the liquid crystal aligning agent obtained in Comparative Example 2, 20 parts by weight of TGDDM was dissolved in 100 parts by weight of polyamic acid to obtain a liquid crystal aligning agent. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 3]
A liquid crystal aligning agent was obtained by adding a mixed solvent of NMP / BC = 1/1 (weight ratio) to PA3 and diluting the whole so that the polyamic acid concentration was 4% by weight. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Example 3]
In 4% by weight of the liquid crystal aligning agent obtained in Comparative Example 3, 20 parts by weight of TGDDM was dissolved in 100 parts by weight of polyamic acid to obtain a liquid crystal aligning agent. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 4]
A liquid crystal aligning agent was obtained by adding a mixed solvent of NMP / BC = 1/1 (weight ratio) to PA4 and diluting the whole so that the concentration of polyamic acid was 4% by weight. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Example 4]
In 4% by weight of the liquid crystal aligning agent obtained in Comparative Example 4, 20 parts by weight of TGDDM was dissolved in 100 parts by weight of polyamic acid to obtain a liquid crystal aligning agent. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 5]
A liquid crystal aligning agent was obtained by adding a mixed solvent of NMP / BC = 1/1 (weight ratio) to PA5 and diluting the whole so that the concentration of polyamic acid was 4% by weight. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Example 5]
In 4% by weight of the liquid crystal aligning agent obtained in Comparative Example 5, 20 parts by weight of TGDDM was dissolved in 100 parts by weight of polyamic acid to obtain a liquid crystal aligning agent. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 6]
A mixed solvent of NMP / BC = 1/1 (weight ratio) is added to PA6 to dilute the whole so that the concentration of polyamic acid is 4% by weight, and 20 parts by weight of TGDDM is added to 100 parts by weight of polyamic acid. A liquid crystal aligning agent was obtained by dissolution. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 7]
A mixed solvent of NMP / BC = 1/1 (weight ratio) is added to PA7 to dilute the whole so that the concentration of polyamic acid is 4% by weight, and 20 parts by weight of TGDDM is added to 100 parts by weight of polyamic acid. A liquid crystal aligning agent was obtained by dissolution. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 8]
A mixed solvent of NMP / BC = 1/1 (weight ratio) is added to PA8 to dilute the whole so that the concentration of polyamic acid is 4% by weight, and 20 parts by weight of TGDDM is added to 100 parts by weight of polyamic acid. A liquid crystal aligning agent was obtained by dissolution. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 9]
A mixed solvent of NMP / BC = 1/1 (weight ratio) is added to PA9 to dilute the whole so that the concentration of polyamic acid is 4% by weight, and 20 parts by weight of TGDDM is added to 100 parts by weight of polyamic acid. A liquid crystal aligning agent was obtained by dissolution. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

[Comparative Example 10]
A mixed solvent of NMP / BC = 1/1 (weight ratio) is added to PA10 to dilute the whole so that the concentration of polyamic acid is 4% by weight, and 20 parts by weight of TGDDM is added to 100 parts by weight of polyamic acid. A liquid crystal aligning agent was obtained by dissolution. A liquid crystal display element was produced as described above using the obtained liquid crystal aligning agent.

<3. Evaluation of residual voltage>
The residual voltage was measured about the liquid crystal display element produced in Examples 1-5 and Comparative Examples 1-10. In the measurement, a 30 Hz, 1.62 V rectangular wave biased with a direct current of 3 V was applied to the liquid crystal display element for 30 minutes, and the voltage remaining in the liquid crystal cell immediately after the DC voltage was turned off was obtained by a flicker erasing method. It can be said that the seizure phenomenon is less likely to occur as the residual voltage value is smaller. The results are shown in Table 2.

  As shown in Table 2, in the liquid crystal display element using the liquid crystal aligning agent of Examples 1 to 5 to which the epoxy compound was added, the residual was compared with the liquid crystal aligning agent of Comparative Examples 1 to 5 to which no epoxy compound was added. The voltage can be reduced. Moreover, in the liquid crystal display element using the liquid crystal aligning agent of Examples 1-4, a residual voltage can be reduced compared with the liquid crystal aligning agent of Comparative Examples 6-8. Furthermore, in the liquid crystal display element using the liquid crystal aligning agent of Example 5, a residual voltage can be reduced compared with the liquid crystal aligning agent of Comparative Examples 9-10.

Claims (15)

A liquid crystal aligning agent comprising polyamic acid or a derivative thereof, which is a reaction product of diamine or a derivative thereof and tetracarboxylic acid or a derivative thereof, and an epoxy compound having two or more epoxy groups,
The diamine or a derivative thereof is a liquid crystal aligning agent containing a diamine represented by the following general formula (I).

(In the general formula (I), -X ¹ - is, -S-, or -S- (CH ₂₎ a bivalent group represented by _n -S-, n is 1 to 16 integer .) The —X ¹ — of the diamine represented by the general formula (I) is —S—, —S—CH ₂ —S—, —S— (CH ₂ ) ₂ —S—, —S— (CH ₂ ). _{3 -S -, - S- (CH} 2) 4 -S -, - S- (CH 2) 5 -S- or -S- (CH ₂₎ liquid crystal alignment according to claim 1 ₆ is -S- Agent. The —X ¹ — of the diamine represented by the general formula (I) is —S—, —S—CH ₂ —S—, —S— (CH ₂ ) ₂ —S—, —S— (CH ₂ ). _{3 -S -, - S- (CH} 2) 4 -S- or -S- (CH _{2) 5} liquid crystal aligning agent according to claim 1 -S- and is. The tetracarboxylic acid or a derivative thereof includes one or more tetracarboxylic dianhydrides represented by the following structural formulas (1), (14), and (i), and the diamine or a derivative thereof is further represented by the following general formula ( The liquid crystal aligning agent in any one of Claims 1-3 containing the 1 or more types of diamine represented by A)-(D) and (XII-A).

(In the general formula (A), n is an integer from 1 to 12. Formula (B1), (B2) and (B3) in, -Y ^1, -Y ^2, and -Y ³ are each independently -H or alkyl having 1 to 30 carbon atoms, and in general formula (D), A ¹ is independently-(CH ₂ ) _m -or -N (CH ₃ )-(CH ₂ ) _m-. Represents N (CH ₃ ) —, where m represents an integer of 1 to 12. In the general formula (XII-A), —Y ⁴ represents an alkyl having 1 to 30 carbon atoms;

Or

In and, -Y ⁵ and -Y ⁶ are each independently alkyl having 1 to 30 carbon atoms, X ² is -CH ₂ - represents or -O-. ) The diamines represented by the general formulas (A) to (D) and (XII-A) are represented by the following structural formulas (A1), (B1-1), (B2-1), (B3-1), (C1). , (C2), (C3), (D1), (D2), (D3), (D4), (XII-2-1), (XII-4-1) and (XII-7-1). The liquid crystal aligning agent according to claim 4, which is one or more diamines.

The liquid crystal alignment according to claim 5, wherein the diamine or a derivative thereof is one or more diamines represented by the following structural formulas (A1), (C1), (C2), (C3), (D1), and (D2). Agent.

The liquid crystal aligning agent according to claim 6, wherein the diamine or a derivative thereof is one or more diamines represented by the following structural formulas (A1), (D1), and (D2).

The diamine or a derivative thereof is one or more represented by the following structural formulas (D2), (D3), (D4), (XII-2-1), (XII-4-1) and (XII-7-1) The liquid crystal aligning agent according to claim 5, which is a diamine.

The liquid crystal alignment according to claim 8, wherein the diamine or a derivative thereof is one or more diamines represented by the following structural formulas (XII-2-1), (XII-4-1), and (XII-7-1). Agent.

The liquid crystal aligning agent according to claim 5, wherein the diamine or a derivative thereof is one or more diamines represented by the following structural formulas (B1-1), (B2-1), (B3-1), and (D1).

  One or more diamines represented by the structural formulas (B1-1), (B2-1), (B3-1) and (D1) are diamines represented by the structural formula (B1-1), and the structure The liquid crystal according to claim 10, wherein the one or more tetracarboxylic dianhydrides represented by the formulas (1), (14) and (i) are tetracarboxylic dianhydrides represented by the structural formula (14). Alignment agent.   The epoxy compound is selected from the group consisting of glycidyl ether, glycidyl ester, glycidyl amine, epoxy group-containing acrylic resin, glycidyl amide, glycidyl isocyanurate, chain aliphatic epoxy compound, and cyclic aliphatic epoxy compound. It is the above, The liquid crystal aligning agent as described in any one of Claims 1-11.   The epoxy compound is N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′— Tetraglycidyl-4,4'-diaminodiphenylmethane, 2- [4- (2,3-epoxypropoxy) phenyl] -2- [4- [1,1-bis [4-([2,3-epoxypropoxy]] Phenyl)] ethyl] phenyl] propane, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, N-phenylmaleimide-glycidyl methacrylate copolymer, bisphenol A novolak type epoxy compound, cresol novolak type Selected from epoxy compounds and N, N, O-triglycidyl-p-aminophenol The liquid crystal aligning agent according to claim 12, characterized in that one or more that.   The liquid crystal aligning film formed by baking the film | membrane of the liquid crystal aligning agent as described in any one of Claims 1-13.   A pair of substrates disposed opposite to each other, electrodes formed on one or both of the opposed surfaces of the pair of substrates, and liquid crystal formed on the opposed surfaces of the pair of substrates. A liquid crystal display element having an alignment film and a liquid crystal layer formed between the pair of substrates, wherein the liquid crystal alignment film is the liquid crystal alignment film according to claim 14.