KR20110097650A - Liquid crystal aligning agents, liquid crystal aligning layers and liquid crystal display devices - Google Patents

Abstract

식 (I) 에 있어서의 X 는 탄소수 2 ∼ 12 의 알킬렌이다. The present invention provides a liquid crystal aligning agent containing at least one polymer selected from polyamic acid and derivatives thereof obtained by reacting a mixture of tetracarboxylic dianhydride and other tetracarboxylic dianhydride represented by formula (I) with diamine. to be. Based on the total amount of the mixture of this tetracarboxylic dianhydride, the ratio of the tetracarboxylic dianhydride represented by Formula (I) is 5-95 mol%, and the ratio of the other tetracarboxylic dianhydride is It is characterized by 5-95 mol%. By using the liquid crystal aligning agent of this invention, the liquid crystal aligning property is high and a favorable black level can obtain the liquid crystal aligning film.

X in Formula (I) is C2-C12 alkylene.

Description

Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element {LIQUID CRYSTAL ALIGNING AGENTS, LIQUID CRYSTAL ALIGNING LAYERS AND LIQUID CRYSTAL DISPLAY DEVICES}

This invention relates to the liquid crystal aligning agent containing a polyamic acid or its derivative (s), and its use.

Liquid crystal display elements have been used in various liquid crystal display devices such as monitors of note PCs and desktop PCs, viewfinders of projection cameras, projection displays, and the like. It is also used as an optoelectronics related element, such as an optical printer head, an optical Fourier conversion element, a light valve.

The liquid crystal display device is usually 1) a pair of substrates arranged oppositely, 2) electrodes formed on one or both sides of the pair of substrates facing each other, and 3) a pair of substrates facing each other. And a liquid crystal layer formed between the pair of substrates.

Conventional liquid crystal display elements are mainly display elements using nematic liquid crystals, 1) twisted nematic (TN) type liquid crystal display elements twisted at 90 degrees, and 2) STN (Super Twisted Nematic) type liquid crystals twisted at least 180 degrees. Element, 3) A so-called TFT (Thin Film Transistor) type liquid crystal display element using a thin film transistor as a switching element of a voltage for driving a liquid crystal has been put into practical use. These liquid crystal display elements have a drawback in that the viewing angle at which an image can be appropriately viewed is narrow, causing a decrease in luminance and contrast and inversion of luminance in halftones when viewed in an inclined direction.

Recently, in view of this viewing angle problem, 1) TN-TFT mode liquid crystal display element using an optical compensation film, 2) vertical alignment and VA (Vertical Alignment) mode liquid crystal display element using an optical compensation film, 3) vertical alignment and projection MVA (Multi Domain Vertical Alignment) mode liquid crystal display element using a technique of a structure, or 4) In-Plane Switching (IPS) mode liquid crystal display element of a transverse electric field system, etc., are improved, and each element is put to practical use, have.

The development of the technology of a liquid crystal display element is achieved not only by the improvement of these drive system and element structure but also the improvement of the structural member used for an element. Among the constituent members used in the liquid crystal display element, in particular, the liquid crystal alignment film is one of important materials related to the display quality, and it is important to improve the performance of the alignment film as the quality of the liquid crystal display element is improved.

A liquid crystal aligning film is prepared from a liquid crystal aligning agent. Currently, the liquid crystal aligning agent mainly used is the solution which melt | dissolved the polyamic acid or soluble polyimide in the organic solvent. After applying such a solution to a substrate, a film is formed by means of heating or the like to form an alignment film. Although the liquid crystal aligning agent using polymers other than a polyamic acid is also examined, it is hardly put into practical use from a viewpoint of heat resistance, chemical-resistance (liquid crystal resistance), applicability | paintability, liquid crystal alignability, electrical characteristics, optical characteristics, display characteristics, etc.

In such an alignment film, the effect brought about by the following liquid crystal display element is calculated | required.

(1) Give an appropriate pretilt angle to liquid crystal molecules. In addition, the pretilt angle is unlikely to be affected by the indentation strength at the time of rubbing or the temperature condition at the time of heating.

(2) The defect of the orientation of a liquid crystal molecule should not generate | occur | produce by rubbing nonuniformity, a flaw, or cutting of an orientation film.

(3) Provide an appropriate voltage holding ratio (VHR) to the liquid crystal display element.

(4) After the arbitrary image is displayed on the liquid crystal display element for a long time, the phenomenon of "transfer" in which the previous image remains as an afterimage is difficult to occur when the image is changed to another image.

As described above, the liquid crystal display element using the VA mode or the IPS mode has been used in most of the liquid crystal TVs that have been recently developed because of the good viewing angle characteristics. When the performances of the two modes are compared, there is one piece of work each due to the driving principle. For example, in the IPS mode, the viewing angle characteristic is particularly good, and the response speed in the halftone is relatively high. However, the contrast is bad compared to the VA mode. In the IPS mode, black is displayed when voltage is not applied. One of the causes of the deterioration of contrast is that this state depends on the initial alignment state of the liquid crystal accompanying rubbing. In short, in the IPS alignment film, an alignment film having a high liquid crystal alignment property and capable of displaying a black display more black (a black level is good) is strongly required. Patent document 1 is mentioned as an example of the prior art aimed at solving such a subject, The technique of this document is characterized by using the diamine which has a triple bond at the terminal.

Japanese Unexamined Patent Publication No. 2009-300940

An object of this invention is to develop the liquid crystal aligning agent for obtaining the liquid crystal aligning film with high liquid crystal alignability and favorable black level.

MEANS TO SOLVE THE PROBLEM The present inventors discovered that the liquid crystal display element with the said characteristic was improved by using the liquid crystal aligning agent containing the polyamic acid which has a specific structure, or its derivative (s), and completed this invention. That is, the liquid crystal aligning agent of this invention is shown in following [1] term.

[1] A composition containing at least one polymer selected from polyamic acid and derivatives thereof obtained by reacting a mixture of tetracarboxylic dianhydride and other tetracarboxylic dianhydride represented by formula (I) with diamine, Based on the total amount of the mixture of this tetracarboxylic dianhydride, the ratio of the tetracarboxylic dianhydride represented by Formula (I) is 5-95 mol%, and the ratio of the other tetracarboxylic dianhydride is 5-95 mol% of liquid crystal aligning agents:

Here, X is a C2-C12 alkylene.

Moreover, the example which used the polyamic acid obtained using the tetracarboxylic dianhydride of Formula (I) for a liquid crystal aligning agent is disclosed by Unexamined-Japanese-Patent No. 2001-131285. However, there is no specific example using the mixture of tetracarboxylic dianhydride and other tetracarboxylic dianhydride of Formula (I) in this prior document, and there is no technique regarding the improvement of a black level. Moreover, the example of the diamine which becomes a reaction partner is also limited.

Based on this invention, the liquid crystal aligning agent with favorable orientation can be obtained. It is particularly effective for improving the black level regarding the IPS mode.

First, the term used by this invention is demonstrated. Tetracarboxylic dianhydride may be abbreviated as acid anhydride, and therefore, tetracarboxylic dianhydride represented by Formula (I) may be abbreviated as acid anhydride (I). Tetracarboxylic dianhydride represented by another formula may also be represented by the same abbreviation method. The diamine represented by Formula (2) may be called diamine (2). Diamine represented by another formula may also be represented by the same abbreviation method.

The term "arbitrary" used in the definition of a chemical formula means "a thing which can be selected freely not only in position but also in number." For example, the expression "any A may be substituted with B, C, D or E" means that one A may be substituted with B, C, D or E, and both of the plurality of A are B In addition to the meaning of being substituted with any one of C, D and E, at least two of A substituted with B, A substituted with C, A substituted with D, and A substituted with E may also be mixed. Have However, any -CH ₂ - that is to be substituted with another, a plurality of successive -CH ₂ - are not included in the same group is substituted.

The substituent which is not specifically bonded to any one of the carbons constituting the ring means that the bonding position is free within a chemically problematic range.

When the same symbol is used in a plurality of formulas, it means that the group has the same definition range, but it does not mean that the group must be the same group in all formulas at the same time. In such a case, the same group may be selected in several formula, and a different group may be selected for every formula. Under the present circumstances, when several same symbol is used for one formula, all of these some group may differ from the group in another formula, and only a part may differ.

Me in the formula means methyl.

This invention consists of said [1] term | item and following [2]-[12] term | item.

[2] Other tetracarboxylic dianhydride is at least one of tetracarboxylic dianhydride represented by formula (A-1) to formula (A-46), and diamine is formula (1-1) to formula (1 The liquid crystal aligning agent of [1] term | claim which is at least 1 diamine chosen from -3), the diamine group represented by Formula (2), Formula (3), and Formula (4):

In formula (1-1), b is 0 or 1; arbitrary hydrogen in cyclohexylene may be substituted by methyl;

In formula (1-2), W ¹ is -CH ₂ -or -NH-:

X ¹ is a single bond or alkylene having 1 to 10 carbon atoms; and any -CH ₂ -of this alkylene is -O-, -S-, -NH-, -N (CH ₃ )-,- Substituted by C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -SO _2- , 1,3-phenylene, 1,4-phenylene or piperazine-1,4-diyl May be;

In formula (3), X <^2> is single-bond, -O-, -COO-, -OCO-, or C1-C6 alkylene; R <^1> is C3-C30 alkyl or Formula (a) It is group to represent;

In formula (a), X ³ and X ⁴ are independently a single bond or alkylene having 1 to 4 carbon atoms; ring B and ring C are independently 1,4-phenylene or 1,4-cyclohexylene R ² and R ³ are independently fluorine or methyl, f and g are independently 0, 1 or 2; c, d and e are independently 0 or 1, and the sum thereof is 1 to 3; R ⁴ is alkyl of 1 to 30 carbon atoms, alkoxy of 1 to 30 carbon atoms, alkoxyalkyl or cholesteryl group of 2 to 30 carbon atoms, and in these alkyl, alkoxy and alkoxyalkyl, arbitrary hydrogen may be substituted with fluorine:

X ⁵ is independently —O— or alkylene having 1 to 6 carbon atoms; j is 0 or 1; R ⁵ is hydrogen, alkyl having 2 to 12 carbon atoms or alkoxy having 2 to 12 carbon atoms; ring T Is 1,4-phenylene or 1,4-cyclohexylene; X ⁶ is a single bond or alkylene having 1 to 3 carbon atoms; h is 0 or 1;

[3] Other tetracarboxylic dianhydride is formula (A-1) to formula (A-4), formula (A-11), formula (A-12), formula (A-14), formula (A -18)-formula (A-21), formula (A-28)-formula (A-30), formula (A-32), formula (A-37), formula (A-39)-formula (A- 41) and at least one of tetracarboxylic anhydrides represented by formulas (A-43) to (A-46), and diamine is formula (1-2-1), formula (1-3), formula (2- 1) to formula (2-3), formula (2-7), formula (2-10) to formula (2-27), formula (2-29), formula (2-37) to formula (2-39 ), Formula (2-41), formula (2-43) to formula (2-47), formula (2-51), formula (3-1) to formula (3-12), and formula (4-1) -The liquid crystal aligning agent as described in [2] which is at least one of diamine represented by Formula (4-12):

R ²⁰ is alkyl having 5 to 16 carbons, R ²¹ is alkyl having 3 to 10 carbons, and R ²² is alkyl or cholesteryl group having 6 to 16 carbons;

R ²⁶ is alkyl having 4 to 7 carbons here.

[4] Other tetracarboxylic dianhydride is formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A -20), tetracarboxyl represented by formula (A-21), formula (A-28), formula (A-30), formula (A-37), formula (A-40) and formula (A-45) At least one acid anhydride, diamine is formula (1-2-1), formula (1-3), formula (2-7), formula (2-10) to formula (2-12), formula (2- 16) to formula (2-19), formula (2-21) to formula (2-27), formula (2-37) to formula (2-39), formula (2-41), formula (2-43) ) Is at least one of the diamine represented by formula (2-47), formula (2-51), formula (3-1) to formula (3-12) and formula (4-1) to formula (4-12). The liquid crystal aligning agent of [3] term | claim.

[5] Tetracar, wherein other tetracarboxylic dianhydride is represented by formula (A-1), formula (A-12), formula (A-14), formula (A-18) and formula (A-45) At least one of the acid anhydrides, diamine is formula (1-2-1), formula (1-3), formula (2-7), formula (2-10) to formula (2-12), formula (2 -26) The liquid crystal aligning agent as described in [4] which is at least one of diamine represented by Formula (2-44), Formula (2-45), and Formula (3-1)-Formula (3-6).

[6] Other tetracarboxylic dianhydride is formula (A-14), formula (A-18), formula (A-19), formula (A-20), formula (A-21), formula (A -28), formula (A-29), formula (A-30), formula (A-32), formula (A-39), formula (A-40), formula (A-41), formula (A- 43), at least one of tetracarboxylic anhydrides represented by formula (A-44) and formula (A-46), and diamine is formula (1-2-1), formula (1-3), formula (2- 1) to formula (2-3), formula (2-26), formula (2-29), formula (2-37), formula (2-43) to formula (2-47), formula (3-1 The liquid crystal aligning agent as described in [3] which is at least one of the diamine represented by-) Formula (3-12) and Formula (4-1)-Formula (4-12).

[7] Other tetracarboxylic dianhydrides are formula (A-14), formula (A-20), formula (A-21), formula (A-39), formula (A-44) and formula (A -46) and at least one of tetracarboxylic anhydrides represented by diamine is formula (1-2-1), formula (1-3), formula (2-1) to formula (2-3), and formula (2). -26) The liquid crystal aligning agent of [6] term | claim which is at least one of diamine represented by Formula (2-29), Formula (2-44), and Formula (3-1)-Formula (3-6).

[8] Other tetracarboxylic dianhydride is formula (A-1), formula (A-2), formula (A-3), formula (A-4), formula (A-11), formula (A -12) and at least one of tetracarboxylic anhydrides represented by formula (A-45), wherein diamine is formula (1-2-1), formula (1-3), formula (2-1) to formula (2) -3), formula (2-13) to formula (2-15), formula (2-20) to formula (2-26), formula (2-29), formula (2-39) and formula (2- The liquid crystal aligning agent as described in [3] which is at least one of diamine represented by 41).

[9] Tetracar, wherein other tetracarboxylic dianhydride is represented by formula (A-1), formula (A-2), formula (A-4), formula (A-12) and formula (A-45) At least one of the acid anhydrides, diamine is formula (1-2-1), formula (1-3), formula (2-1) to formula (2-3), formula (2-13) to formula (2 -15) The liquid crystal aligning agent as described in [8] term | claim which is at least one of diamine represented by Formula (2-26) and Formula (2-29).

[10] Any of [1] to [9], further containing at least one polymer selected from other polyamic acids and derivatives thereof produced without using tetracarboxylic dianhydride represented by formula (I). The liquid crystal aligning agent of one term | claim.

[11] A liquid crystal aligning film formed by heating the coating film of the liquid crystal aligning agent in any one of [1]-[10].

[12] A liquid crystal display device comprising a pair of substrates and a liquid crystal layer formed between the substrates, an electrode for applying a voltage to the liquid crystal layer, and the liquid crystal alignment film according to [11].

The liquid crystal aligning agent of this invention is a composition containing the at least 1 polymer and solvent chosen from polyamic acid and its derivative (s). As the derivative of the polyamic acid, a part of a polyimide obtained by completely dehydrating the ring-closure reaction of the polyamic acid, a partially imidized polyamic acid, a polyamic acid ester, and a tetracarboxylic dianhydride obtained by partially dehydrating the ring-closure reaction of the polyamic acid is dicarboxed. The polyamideimide obtained by carrying out the dehydration ring-closure reaction of the polyamic-acid-polyamide copolymer obtained by substitution with an acid, and part or all of this polyamic-acid-polyamide copolymer is mentioned. Among these, polyimide and partially imidized polyamic acid are preferable, and polyimide is more preferable.

In the present invention, at least one polymer selected from the group consisting of polyamic acid and derivatives thereof obtained by reacting a mixture of acid anhydride (I) and other acid anhydride with diamine is used.

X in Formula (I) is C2-C12 alkylene. The alkylene is preferably a linear alkylene having 5 to 12 carbon atoms, because it gives a large liquid crystal alignment property to the alignment film.

This polymer may be used alone or in combination of at least two polyamic acids having different raw materials, or may be used in combination of the polyamic acid and its derivatives. In addition, as will be described later, at least one polymer selected from the polyamic acid and its derivatives, and other polyamic acid obtained without using the acid anhydride (I) and at least one polymer selected from the derivatives thereof may be used in combination. You may also In addition, in the following description except an Example, "polyamic acid" used without tin means the generic name of the polyamic acid obtained by reacting a mixture of an acid anhydride (I) and other acid anhydrides with diamine, and its derivatives. Has

The other acid anhydrides used in combination with the acid anhydride (I) can be selected without being limited from known acid anhydrides. Examples of the acid anhydride (A-1) to the acid anhydride (A-46) shown below are preferable examples. Can be mentioned. It is preferable to use at least one of these acid anhydrides.

As other acid anhydrides, among the above acid anhydrides, an acid anhydride (A-1) to an acid anhydride (A-4), an acid anhydride (A-11), an acid anhydride (A-12) and an acid anhydride (A) shown below -14), acid anhydride (A-18)-acid anhydride (A-21), acid anhydride (A-28)-acid anhydride (A-30), acid anhydride (A-32), acid anhydride (A-37 ), Acid anhydride (A-39) to acid anhydride (A-41), and acid anhydride (A-43) to acid anhydride (A-46) are more preferable.

In the case where emphasis is placed on further improving the orientation of the liquid crystal, an acid anhydride (A-1), an acid anhydride (A-2), an acid anhydride (A-12) and an acid anhydride (A-14) among the other acid anhydrides described above. ), Acid anhydride (A-18), acid anhydride (A-20), acid anhydride (A-21), acid anhydride (A-28), acid anhydride (A-30), acid anhydride (A-37), Acid anhydrides (A-40) and (A-45) are more preferable, and acid anhydrides (A-1), acid anhydrides (A-12), acid anhydrides (A-14), acid anhydrides (A-18) and (A-45) is especially preferable.

When it is important to improve the VHR of the liquid crystal display device, among the above other acid anhydrides, an acid anhydride (A-14), an acid anhydride (A-18), an acid anhydride (A-19) and an acid anhydride (A- 20), acid anhydride (A-21), acid anhydride (A-28), acid anhydride (A-29), acid anhydride (A-30), acid anhydride (A-32), acid anhydride (A-39) More preferred are alicyclic compounds of acid anhydride (A-40), acid anhydride (A-41), acid anhydride (A-43), acid anhydride (A-44) and acid anhydride (A-46). Especially preferred are anhydrides (A-14), acid anhydrides (A-20), acid anhydrides (A-21), acid anhydrides (A-39), acid anhydrides (A-44) and acid anhydrides (A-46). .

By lowering the volume resistance value of the liquid crystal aligning film, improving the relaxation rate of the residual charge (residual DC) in the alignment film is effective as one of methods for preventing the transfer. In the case where the object is important, among the other acid anhydrides, an acid anhydride (A-1), an acid anhydride (A-2), an acid anhydride (A-3), an acid anhydride (A-4), an acid anhydride ( A-11), acid anhydride (A-12) and acid anhydride (A-45) are more preferable, and acid anhydride (A-1), acid anhydride (A-2), acid anhydride (A-4), and acid Especially preferred are anhydrides (A-12) and acid anhydrides (A-45). An acid anhydride is not limited to these, You may use another well-known compound within the range in which the objective of this invention is achieved.

These mixing ratios in the mixture of the acid anhydride (I) and other acid anhydride are ratios based on the total amount of this mixture, and the acid anhydride (I) is 5-95 mol%, and other acid anhydrides It is 5-95 mol%. As for this mixing ratio, it is preferable that acid anhydride (I) is 15-85 mol%, and other acid anhydride is 15-85 mol%.

The diamine used in the present invention is selected without limitation from known diamines, and as preferred diamines, diamine (1-1) to diamine (1-3), diamine (2), diamine (3) and diamine ( 4) can be mentioned. Preference is given to using at least one diamine selected from the group of these diamines.

In Formula (1-1), b is 0 or 1, and arbitrary hydrogen in cyclohexylene may be substituted by methyl.

In Formula (1-2), W ¹ is -CH ₂ -or -NH-.

Specific examples of these diamines are shown below.

In the formula (2), X ¹ is a single bond or alkylene having 1 to 10 carbon atoms, in the alkylene arbitrary -CH ₂ - is -O-, -S-, -NH-, -N ( CH 3 )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -SO _2- , 1,3-phenylene, 1,4-phenylene or piperazine-1,4 It may be substituted by -diyl. Preferred examples of X ¹ are alkylene having 1 to 10 carbon atoms, wherein any -CH ₂ -of alkylene is -O-, -S-, -NH-, -C (CH ₃ ) _2- , 1, It may be substituted with 4-phenylene or piperazine-1,4-diyl. And although arbitrary hydrogen of the benzene ring which an amino group couple | bonds may be substituted by methyl, it is preferable that it is not substituted by methyl.

The specific example of diamine (2) is shown next.

In Formula (3), X <^2> is a single bond, -O-, -COO-, -OCO-, or C1-C6 alkylene, Preferably it is a single bond, -O-, -COO-, or C1 Alkylene of -3. R <^1> is a C3-C30 alkyl or group represented by Formula (a), Preferably it is a C4-C20 alkyl or group represented by Formula (a).

In the formula (a), X ³ and X ⁴ are independently a single bond or alkylene having 1 to 4 carbon atoms, preferably a single bond, -CH ₂ -or -CH ₂ CH _2- . Ring B and Ring C are independently 1,4-phenylene or 1,4-cyclohexylene. R ² and R ³ are independently fluorine or methyl, and f and g are independently 0, 1 or 2, but it is preferable that both f and g are zero. c, d, and e are 0 or 1 independently, and the sum total is 1-3. R ⁴ is alkyl having 1 to 30 carbons, alkoxy having 1 to 30 carbons, alkoxyalkyl or cholesteryl group having 2 to 30 carbon atoms, and in these alkyls, alkoxy and alkoxyalkyl, arbitrary hydrogen may be substituted with fluorine. Preferred examples of R ⁴ are alkyl having 1 to 20 carbons, alkoxy having 1 to 20 carbons, alkoxyalkyl and cholesteryl group having 2 to 20 carbons, and hydrogen in these alkyls, alkoxy and alkoxyalkyl is substituted with fluorine. There is no case.

Preferred examples of the diamine (3) are as follows.

In Formulas (3-1) to (3-25), R ²⁰ is alkyl having 1 to 20 carbon atoms or alkoxy having 1 to 20 carbon atoms, preferably alkyl having 5 to 16 carbon atoms. R <^21> is C1-C20 alkyl or C1-C20 alkoxy, Preferably it is C3-C10 alkyl. R ²² is an alkyl or cholesteryl group having 4 to 20 carbon atoms, preferably an alkyl or cholesteryl group having 6 to 16 carbon atoms. R ²³ is alkyl having 4 to 20 carbons, preferably alkyl having 6 to 16 carbons. R <^24> is C3-C20 alkyl or C3-C20 alkoxy, Preferably it is C5-C12 alkyl.

In the formula (4), X ⁵ is independently -O- or an alkylene group having 1 to 6 carbon atoms, preferably all -O-, -CH ₂ - or -CH ₂ CH ₂ - is. j is 0 or 1. R ⁵ is hydrogen, alkyl having 1 to 20 carbon atoms or alkoxy having 1 to 20 carbon atoms, preferably hydrogen, alkyl having 1 to 12 carbon atoms or alkoxy having 1 to 12 carbon atoms, and more preferably alkyl having 4 to 7 carbon atoms. to be. Ring T is 1,4-phenylene or 1,4-cyclohexylene. X ⁶ is a single bond or alkylene having 1 to 3 carbon atoms. And h is 0 or 1. In addition, it is preferable that the bonding position of the amino group with respect to the benzene ring is a para position with respect to X <^5> .

Preferred examples of the diamine (4) are as follows.

In formulas (4-1) to (4-16), R ²⁶ is hydrogen, alkyl having 1 to 12 carbons or alkoxy having 1 to 12 carbons, preferably alkyl having 4 to 7 carbons.

In the specific example of the said diamine, the following diamine (1-2-1), diamine (1-3), diamine (2-1)-diamine (2-3), diamine (2-7), diamine (2 -10) to diamine (2-27), diamine (2-29), diamine (2-37) to diamine (2-39), diamine (2-41), diamine (2-43) to diamine (2- 47), diamine (2-51), diamine (3-1) -diamine (3-12), and diamine (4-1) -diamine (4-12) are more preferable.

R ²⁰ is alkyl having 5 to 16 carbons, R ²¹ is alkyl having 3 to 10 carbons, and R ²² is alkyl or cholesteryl group having 6 to 16 carbons.

R ²⁶ is alkyl having 4 to 7 carbons here.

In the specific example of said more preferable diamine, when it makes much emphasis on further improving the orientation of a liquid crystal, diamine (1-2-1), diamine (1-3), diamine (2-7), diamine (2- 10) to diamine (2-12), diamine (2-16) to diamine (2-19), diamine (2-21) to diamine (2-27), diamine (2-37) to diamine (2-39 ), Diamine (2-41), diamine (2-43) to diamine (2-47), diamine (2-51), diamine (3-1) to diamine (3-11), and diamine (4-1 ) -Diamine (4-12) are more preferable, diamine (1-2-1), diamine (1-3), diamine (2-7), diamine (2-10)-diamine (2-12), Diamine (2-26), diamine (2-44), diamine (2-45), and diamine (3-1) -diamine (3-6) are especially preferable.

In the specific example of the said more preferable diamine, when attaching importance to giving high VHR to a liquid crystal aligning film, diamine (1-2-1), diamine (1-3), diamine (2-1)-diamine (2 -3), diamine (2-26), diamine (2-29), diamine (2-37), diamine (2-43) to diamine (2-47), diamine (3-1) to diamine (3- 11) and diamine (4-1) -diamine (4-12) are more preferable, diamine (2-1) -diamine (2-3), diamine (2-26), diamine (2-29), Diamine (2-44) and diamine (3-1) -diamine (3-6) are especially preferable.

In the specific example of said more preferable diamine, when focusing on reducing the volume resistance value of a liquid crystal aligning film, diamine (1-2-1), diamine (1-3), diamine (2-1)-diamine ( 2-3), diamine (2-13) to diamine (2-15), diamine (2-20) to diamine (2-26), diamine (2-29), diamine (2-39) and diamine (2 -41) are more preferable, and diamine (2-1)-diamine (2-3), diamine (2-13)-diamine (2-15), diamine (2-26), and diamine (2-29) are Particularly preferred.

By the way, diamine can be divided into two types according to the difference of the structure. That is, when looking at the backbone chain which connects two amino groups as a main chain, it is a diamine which does not have a group branched from a main chain, ie, a diamine which has a side chain group, and a side chain group. By reacting the diamine which has a side chain group with tetracarboxylic dianhydride, the polyamic acid which has many side chain groups with respect to the main chain of a polymer is obtained. When the polyamic acid which has a side chain group with respect to such a polymer main chain is used, the liquid crystal aligning film formed from the liquid crystal aligning agent containing this polymer can enlarge the pretilt angle in a liquid crystal display element. That is, this side chain group is group which has an effect which enlarges a pretilt angle. The side chain group having such an effect needs to be a group having 3 or more carbon atoms, and specific examples include groups having 3 or more alkyl, alkoxy 3 or more, and alkoxyalkyl having 3 or more carbon atoms. A group having at least one ring, the ring of which terminal has an effect as an airside side chain group having any one of alkyl having at least 1 carbon, alkoxy having 1 or more alkoxy and alkoxyalkyl having 2 or more carbon atoms as a substituent. When the diamine which has such a side chain group is made into side chain type diamine, and the diamine which does not have such a side chain group is made into non-side chain type diamine, the said diamine (3) and diamine (4) are side chain type diamine, and a diamine ( 1-1) -diamine (1-3) and diamine (2) are non-side-chain diamine.

In addition, by appropriately dividing the side chain diamine and the non-side chain diamine, it is possible to cope with the pretilt angle required for each of the various display elements. That is, the side chain type diamine is mainly used because the transverse electric field system represented by the TN system or VA system requires a relatively large pretilt angle. At this time, in order to further control the pretilt angle, the non-side chain type diamine may be used together. What is necessary is just to determine the compounding ratio of a non-side chain type diamine and a side chain type diamine according to the magnitude | size of the pretilt angle made into the objective. Of course, by selecting a side chain group suitably, it can also respond using only a side chain type diamine. Since the pretilt angle is small and high liquid crystal alignability is needed as a transverse electric field system, at least one of non-side-chain-type diamine may be used.

In this invention, in order to express a pretilt angle of 2 degrees or more especially, it is preferable to make use ratio of a side chain type diamine into 5 to 70 mol% in diamine whole quantity, and to make it into 10-50 mol% more. desirable.

The polyamic acid used for the liquid crystal aligning agent of this invention is obtained by making the mixture and the diamine of the said acid anhydride react in a solvent. In this synthesis reaction, special conditions other than the selection of the raw materials are not necessary, and the conditions in the general polyamic acid synthesis can be applied as it is. The solvent to be used is mentioned later.

In order to prevent cutting by rubbing, you may use together the at least 1 of a siloxane-type diamine to this invention liquid crystal aligning agent. The diamine represented by Formula (15) is mentioned as a preferable example of this siloxane-type diamine.

Wherein R ³⁰ and R ³¹ are independently alkyl or phenyl having 1 to 3 carbon atoms, R ³² is alkylene, phenylene or alkyl substituted phenylene having 1 to 6 carbon atoms, and y is an integer of 1 to 10; .

As specific examples of the diamine (15), the following compounds or polymers may be mentioned.

(Molecular weight of polymer of formula (15-2) is 850-3000)

When using these siloxane diamines, it is preferable that it is 0.5-30 mol% with respect to the whole amount of the diamine used as a raw material, and, as for the addition amount, it is more preferable that it is 1-10 mol%.

The aligning agent of this invention may contain the organosilicon compound further from a viewpoint of adjusting the adhesiveness with respect to the glass substrate of an oriented film. Examples of the organosilicon compound include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, vinyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2- Aminoethyl) -3-aminopropyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxy Silane coupling agents such as silane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and silicone oils such as dimethylpolysiloxane, polydimethylsiloxane, and polydiphenylsiloxane.

There is no restriction | limiting in particular if the addition ratio with respect to the aligning agent of this organosilicon compound is a range from which the effect of this invention is acquired, To say, the density | concentration is the range of 0.01-5 weight% with respect to the weight of the polymer contained in an aligning agent. It is preferable. If it is 5 weight% or less, it is not necessary to consider the possibility of the orientation defect of the liquid crystal resulting from addition of an organosilicon compound. This addition ratio becomes like this. Especially preferably, it is 0.1 to 3 weight% of range.

The aligning agent of the present invention may further contain a compound having two or more functional groups reacting with the carboxyl group of the polyamic acid or its derivatives, and a so-called crosslinking agent, from the viewpoint of preventing the deterioration of the characteristic over time and deterioration due to the environment. do. As an example of such a crosslinking agent, the polyfunctional epoxy, isocyanate material, etc. which are described in Unexamined-Japanese-Patent No. 3049699, Unexamined-Japanese-Patent No. 2005-275360, Unexamined-Japanese-Patent No. 10-212484, etc. are mentioned.

Moreover, the crosslinking agent itself reacts to become a polymer of a net structure, and a crosslinking agent for improving the film strength of polyamic acid or polyimide can also be used for the same purpose as described above. As such a crosslinking agent, the polyfunctional vinyl ether, maleimide, bisallyl naimide derivative etc. which are described in Unexamined-Japanese-Patent No. 10-310608, Unexamined-Japanese-Patent No. 2004-341030, etc. are mentioned. When using these crosslinking agents, the preferable ratio is 5-100 weight% with respect to the total amount of a polymer component, More preferably, it is 10-50 weight%.

Although it is preferable to use at least one of a polyamic acid as a liquid crystal aligning agent of this invention, you may use combining the polyamic acid and the other polyamic acid manufactured without using an acid anhydride (I). The mixing ratio in the case of combining other polyamic acids is 10 to 95% by weight of polyamic acid and 5 to 90% by weight of other polyamic acids based on the total amount of the polymer, and the ratio of the polyamic acid is at least sufficient to obtain an effect. Can be. In the liquid crystal aligning agent of this invention, polymers other than the polyamic acid obtained by reaction of an acid anhydride and diamine, for example, polyester, an epoxy resin, etc. can be used together. However, it is preferable that the ratio at the time of using such another polymer together is 30 weight% or less based on the total weight of a polymer.

The alignment agent of this invention is the solution which melt | dissolved the polyamic acid in the solvent. This solvent can be suitably selected from the solvents used in manufacture and use of well-known polyamic acid, according to the purpose of use. When these solvents are illustrated, it is as follows.

Examples of aprotic polar organic solvents include N-methyl-2-pyrrolidone (NMP), dimethylimidazolidinone, N-methylcaprolactam, N-methylpropionamide, N, N-dimethylacetamide, and dimethylsulfoxide. And lactones such as N, N-dimethylformamide (DMF), N, N-diethylformamide, N, N-diethylacetamide (DMAc), and γ-butyrolactone (GBL). .

As a solvent other than the above, preferable examples of the solvent for the purpose of improving the coating properties include alkyl lactate, 3-methyl-3-methoxybutanol, tetraine, isophorone and ethylene glycol monoalkyl ether (e.g., ethylene glycol mono). Butyl ether (BCS)), diethylene glycol monoalkyl ether (e.g. diethylene glycol monoethyl ether), ethylene glycol monophenyl ether, triethylene glycol monoalkyl ether, propylene glycol monoalkyl ether (e.g. propylene glycol monobutyl ether ), Dialkyl malonate (e.g. diethyl malonate), dipropylene glycol monoalkyl ether (e.g. dipropylene glycol monomethyl ether), and ester compounds of these glycol monoethers. Among these, NMP, dimethyl imidazolidinone, GBL, BCS, diethylene glycol monoethyl ether, propylene glycol monobutyl ether and dipropylene glycol monomethyl ether are particularly preferable.

The alignment agent of this invention can contain various additives further as needed. For example, when a new improvement in applicability is desired, a surfactant corresponding to the purpose may be contained, and an antistatic agent may be contained in an appropriate amount when a new improvement in antistatic is required.

It is preferable that it is 0.1-40 weight%, and, as for the density | concentration of the polymer in the aligning agent of this invention, it is more preferable that it is 1-10 weight%. When adjustment of a film thickness is needed in apply | coating this aligning agent to a board | substrate, it can dilute with a solvent previously and can adjust the density | concentration of a containing polymer.

The alignment film of this invention apply | coats the said aligning agent to a board | substrate according to the method described below, heat-removing (preliminarily baking) a solvent at comparatively low temperature as needed; and then accelerate | stimulates solvent removal further, and the polyamic acid In order to raise the imidation ratio and to express the characteristic of an orientation film, it is obtained by heating (main baking) at comparatively high temperature. The film thus obtained may be subjected to a rubbing treatment as necessary.

The liquid crystal display element of this invention opposes each pair of board | substrates arrange | positioned, the electrode formed in the one or both sides of the opposing surface of each of said pair of board | substrates, and each said pair of board | substrates. It is a liquid crystal display element which has the liquid crystal aligning film of this invention formed in the surface, and the liquid crystal layer formed between the said pair of board | substrates.

The electrode is not particularly limited as long as it is an electrode formed on one surface of the substrate. As such an electrode, ITO, a metal vapor deposition film, etc. are mentioned, for example. Moreover, the electrode may be formed in the whole surface of one surface of a board | substrate, for example, may be formed in the desired shape patterned. As said desired shape of an electrode, a comb-tooth type or a zigzag structure etc. are mentioned, for example. An electrode may be formed in one board | substrate among a pair of board | substrates, and may be formed in both board | substrates. Formation forms of electrodes differ according to the kind of liquid crystal display element, For example, in the case of an IPS type liquid crystal display element, an electrode is arrange | positioned at one side of the said pair of board | substrates, and in the case of other liquid crystal display elements, the said pair The electrodes are arranged on both sides of the substrate. The liquid crystal alignment layer is formed on the substrate or the electrode.

The liquid crystal layer is formed in such a manner that the liquid crystal composition is sandwiched by the pair of substrates on which the surface on which the liquid crystal alignment film is formed is opposed. In formation of a liquid crystal layer, the spacer which forms a suitable space | interval through said pair of board | substrates, such as microparticles | fine-particles and a resin sheet, can be used as needed. The liquid crystal composition is not particularly limited, and a known liquid crystal composition can be used.

When the alignment film of this invention forms a liquid crystal display element as a liquid crystal aligning film, the characteristic can be improved with respect to all the well-known liquid crystal compositions. The alignment film of the present invention produced by the above method is particularly effective in improving alignment defects of large-screen displays that are difficult to perform rubbing treatment. Such a large screen display is driven and controlled by the TFT. Moreover, the liquid crystal composition used for such a TFT type liquid crystal display element is described in Unexamined-Japanese-Patent No. 3086228, Unexamined-Japanese-Patent No. 5-501735, and Unexamined-Japanese-Patent No. 9-255956. have. Therefore, it is preferable to use the alignment film of this invention in combination with the liquid crystal composition as described in these.

The liquid crystal display element of this invention is excellent in orientation, for example, showing high black level value when it uses for IPS. The value of this black level can be measured as follows. That is, the cell assembled with the rubbing direction anti-parallel is arrange | positioned at the stage of a microscope, and a polarizer and an analyzer are rotated so that it may become minimum brightness. The minimum luminance is measured using a photoelectron multiplier tube (100 times magnification of polarizing microscope; 10 times eyepiece × 10 times object). The smaller the luminance value, the better the black level. According to the measurement system, it is very suitable that the minimum luminance is 1500 Hz or less, and more preferably 900 Hz or less. In this application, this minimum luminance value is used as a value of a black level.

The liquid crystal display element of this invention is excellent also in the electrical characteristic which concerns on the reliability of a liquid crystal display element. As such electrical characteristics, voltage retention and ion density are mentioned. The voltage retention VHR is a ratio at which the voltage applied to the liquid crystal display element in the frame main period is maintained in the liquid crystal display element, and represents the display characteristics of the liquid crystal display element. The liquid crystal display of the present invention has a voltage retention of 97.0% or more measured at 60 ° C using a rectangular wave of 5 V and a frequency of 30 Hz, and 60 ° C using a rectangular wave of 5 V and a frequency of 0.3 Hz. It is preferable from the viewpoint of preventing display defects that the voltage retention measured at a temperature condition of is 85.0% or more.

The ion density is a transient current other than that resulting from the driving of the liquid crystal generated when voltage is applied to the liquid crystal display element, and represents the magnitude of the concentration of the ionic impurities contained in the liquid crystal in the liquid crystal display element. It is preferable that the ion density of the liquid crystal display element of this invention is 300 pC or less from a viewpoint of preventing the transfer of a liquid crystal display element.

The pretilt angle in the liquid crystal display element of this invention uses the liquid crystal characteristic evaluation apparatus OMS-CA3 type | mold of central periodic manufacture, for example, Journal of Applied Physics, Vol. 48, No. 5, p.1783-1792 It can measure by the crystal rotation method described in (1977).

Example

Hereinafter, an Example and a comparative example demonstrate this invention.

The evaluation method of the liquid crystal display element in an Example is as follows.

<Retardation, Film Thickness, and Pretilt Angle Measurement of Orientation Film>

It calculated | required using the spectroscopic ellipsometer M-2000U (made by J.A. Woollam Co. Inc.). In the case of this embodiment, the retardation value of the film increases in proportion to the degree of orientation of the polymer main chain. That is, what has a big retardation value has a big orientation degree.

<Voltage retention rate>

It carried out by the method as described in "Mizushima et al. 14th liquid crystal debate notice p78 (1988)". The measurement was performed by applying a rectangular wave of wavelength height ± 5 V to the cell. The measurement was performed at 60 degreeC. This value is an index indicating how much the applied voltage is held after the frame period, and when this value is 100%, it indicates that all charges are held.

<Ion amount measurement in liquid crystal (ion density)>

According to the method of the application physics, Vol. 65, No. 10, 1065 (1996), it measured using the Toyo Technica Corporation make, the liquid crystal physical property measuring system 6254 type. Using a triangular wave with a frequency of 0.01 Hz, the temperature was measured at a voltage range of ± 10 V at a temperature of 60 ° C. (area of electrode was 1 cm 2). If the ion density is large, problems such as transfer by ionic impurities are likely to occur. In other words, the ion density is a physical property value that is an index for predicting transcription occurrence.

<Weight Average Molecular Weight (Mw)>

The weight average molecular weight (Mw) of the polyamic acid in a liquid crystal aligning agent uses the gel permeation chromatography (GPC, Shodex company make, GF7MHQ) and uses 0.6 weight% phosphoric acid containing DMF as eluent, and uses the column The temperature was measured at 50 ° C. using polystyrene as a standard solution.

<Viscosity>

It measured at 25 degreeC using the viscometer (The Toki Sangyo company make, TV-22).

The compound used by the Example and the comparative example is shown below.

Acid Anhydride (I)

Acid anhydride (A-1): pyromellitic dianhydride (PMDA)

Acid anhydride (A-2): 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride (BPDA)

Acid anhydride (A-12): 2,3,6,7-naphthalene tetracarboxylic dianhydride (NPDA)

Acid anhydride (A-14): 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA)

Acid anhydride (A-18): 1,2,3,4-butane tetracarboxylic dianhydride (BDA),

Acid anhydride (A-20): 1,2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA)

Acid anhydride (A-30): Rikaside TDA-100 (Shin Nippon Ewha Co., Ltd.)

Acid anhydride (A-45): Ethylenediaminetetraacetic acid dianhydride (EDTA)

The acid anhydride described above was used after acetic anhydride treatment of a commercially available compound, followed by vacuum drying. Acetic anhydride treatment was performed as follows. First, about each compound, it heated at 80 degreeC for 2 hours using 10 times amount of acetic anhydride and the same amount of toluene as needed. After cooling to room temperature, the precipitate was filtered off.

Acid anhydride (A-21): 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCMP)

Acid anhydride (A-44): 2,4,6,8-tetracarboxybicyclo [3.3.0] octane dianhydride (BODA)

The above acid anhydrides are disclosed in Japanese Patent Application Laid-Open No. 58-109479, J. Am. Chem. Soc., Vol. 82, 6342 (1960).

Diamine (2-1): 4,4'-diaminodiphenylmethane (DDM)

Diamine (2-7): 1, 2-bis (4-aminophenyl) ethane (DD2)

The diamine mentioned above used a commercially available compound as it was for experiment.

Diamine (2-11): 1, 4-bis (4-aminophenyl) butane (DD4)

Diamine (2-26): N, N'-dimethyl-N, N'-bis (4-aminophenyl) ethylenediamine (MPED)

Diamine (2-29): 1, 4-bis (4-aminophenyl) piperazine (APPD)

Diamine (2-44): 1, 3-bis (4- (4-aminophenylmethyl) phenyl) propane (APMPP)

The above diamine is J. Appl. Poly. Sci., Vol. 8, No. 1, 533 (1964), J. Polym. Sci., Part A, Polym. Chem., Vol. 30, No. 6, 1099 (1992), Unexamined-Japanese-Patent No. 51-136917, and Unexamined-Japanese-Patent No. 11-193346 were synthesize | combined according to the method.

Diamine (3-5-1): R ²¹ = pentyl

Diamine (4-6-1): R ²⁶ = heptyl

Diamine (4-9-1): R ²⁶ = Propyl

The above diamine is synthesize | combined with reference to the method of Unexamined-Japanese-Patent No. 2004-341030, EP601813, and Unexamined-Japanese-Patent No. 02-210328, respectively, and is represented by Formula (N) (Hereafter, a compound (N Abbreviated as)) was synthesized by the method described in Japanese Unexamined Patent Publication No. 2002-162630.

In addition, all the preparation of a polymer was performed in nitrogen stream.

Synthesis Example 1

<Preparation of polyamic acid varnish A>

DDM (2.2611 g, 11.405 mmol) was dissolved in NMP (22.5 g) and acid anhydride (I-1) (0.9988 g, 2.851 mmol), PMDA (0.6219 g, 2.851 mmol), and CBDA (1.1183, 5.702 mmol) was added keeping the temperature below room temperature. After stirring for 2 hours, NMP (10.0 g) and BC (12.5 g) were added. The viscosity of this thing was 83 mPa * s. This solution was stirred at 70 degreeC for about 4 hours, and the varnish A of viscosity 34mPa * s was obtained. The weight average molecular weight of the polyamic acid of this varnish was 52,000.

Synthesis Examples 2 to 23

<Preparation of polyamic acid varnishes B to W>

By the raw material composition shown in Table 1 and 2, polyamic acid varnish B-W was prepared by the method similar to the synthesis example 1, and the physical property was measured similarly to the synthesis example 1. In addition, the parenthesis shows mol%.

EXAMPLE 1

<Production of Cells for Measuring Black Levels>

1.0 g of varnish A was measured to the sample bottle, and the mixed solvent of NMP / BC = 1/1 (weight ratio) was added, and it was 1.67 g. On the transparent glass substrate, this polyamic-acid solution of about 3 weight% of this polymer concentration was dripped, and it applied by the spinner method (2,000 rpm, 15 second). After application | coating, the board | substrate was heated at 80 degreeC for 3 minutes, and after evaporating a solvent, it heat-processed at 230 degreeC and 20 minutes in oven. A polyimide film having a thickness of about 70 nm was subjected to a rubbing treatment (indentation; 0.3 mm, stage transfer speed; 60 m / s, rotation speed; 1000 rpm, rubbing cloth; YA-18-R (rayon)). Thereafter, the glass substrate on which the alignment film was formed was ultrasonically cleaned in ultrapure water for 5 minutes, and then dried at 120 ° C in an oven for 30 minutes.

After the surface on which the alignment film was formed was disposed to face the rubbing direction so as to be anti-parallel, an anti-parallel cell having a gap of 25 μm was produced by sealing with an epoxy curing agent containing a 25 μm gap agent. The liquid crystal composition A shown below was injected into this cell, and the injection hole was sealed with the photocuring agent. Subsequently, heat processing were performed for 30 minutes at 110 degreeC, and the liquid crystal display element was manufactured. The black level of this cell was measured and found to be 1,250 Hz.

<Preparation of Cells for Measuring Pretilt Angle and Electrical Properties>

Using the alignment film formation glass substrate produced by carrying out similarly to the above, the 7 micrometers gap agent was spread | dispersed on one alignment film. After arranging this and one board | substrate so that the rubbing direction might become antiparallel with the orientation film surface inside, it was sealed with the epoxy hardening | curing agent, and the antiparallel cell of gap 7micrometer was produced. The liquid crystal composition A was injected into the cell similarly to the above, and the injection hole was sealed with the photocuring agent. Subsequently, heat processing were performed for 30 minutes at 110 degreeC, and the liquid crystal display element was manufactured. The VHR (30 Hz and 0.3 Hz) and ion density of this cell were measured, and found to be 98.3%, 88.8%, and 157 pC.

<Liquid crystal composition A>

[Examples 2-15]

Using varnish B-varnish O shown in Table 1, it carried out similarly to Example 1, and obtained the liquid crystal display element. The value of black level, VHR, and ion density at this time is shown in Table 3 with the result of Example 1. FIG.

[Comparative Example 1]

A liquid crystal display device was produced in the same manner as in Example 1 except that varnish T was used instead of varnish A. The black level, VHR (30 Hz and 0.3 Hz) and ion density of this cell were measured, and the results were 2,810 Pa, 99.0%, 91.5%, and 46 pC.

[Comparative example 2]

A liquid crystal display device was produced in the same manner as in Example 1 except that varnish U was used instead of varnish A. The black level, VHR (30 Hz and 0.3 Hz) and ion density of this cell were measured, and the results were 2,130 Hz, 95.0%, 79.8%, and 421 pC.

[Example 16]

A liquid crystal display device was manufactured in the same manner as in Example 1 except that varnish R was used instead of varnish A. The pretilt angle, VHR (30 Hz and 0.3 Hz), and ion density of this cell were measured, and found to be 5.8 °, 98.7%, 90.0%, and 101 pC. Moreover, it was 0.23 nm as a result of measuring the retardation of the glass substrate in which the orientation film before cell assembly was formed.

[Examples 17-19]

Using varnish S, it carried out similarly to Example 1, and obtained the liquid crystal display element. Moreover, the liquid crystal display element was obtained like Example 1 using the mixture which varnish R and varnish S were added to varnish T, respectively. The pretilt angle, VHR (30 Hz and 0.3 Hz), and ion density value were measured about these liquid crystal display elements, and the retardation measurement value of the glass substrate in which the orientation film before cell assembly was formed is shown in Table 4. In addition, the parenthesis shows a weight%.

EXAMPLE 20

A liquid crystal display device was produced in the same manner as in Example 16 except that 20% by weight of the compound (N) was added to the varnish R with respect to the polymer component. The pretilt angle, VHR (30 Hz and 0.3 Hz) and ion density of this cell were measured, and found to be 5.3 degrees, 99.2%, 92.3%, and 63 pC. Moreover, it was 0.17 nm as a result of measuring the retardation of the glass substrate in which the orientation film before cell assembly was formed.

EXAMPLE 21

A liquid crystal display device was produced in the same manner as in Example 16 except that 3 wt% of 3-aminopropyltrimethoxysilane was added to the varnish R with respect to the polymer component. The pretilt angle, VHR (30 Hz and 0.3 Hz), and ion density of this cell were measured, and the results were 5.5 °, 99.0%, 91.2%, and 96 pC. Moreover, it was 0.18 nm as a result of measuring the retardation of the glass substrate in which the orientation film before cell assembly was formed.

[Comparative Example 3]

A liquid crystal display device was produced in the same manner as in Example 16 except that a varnish V was used instead of the varnish R. The pretilt angle, VHR (30 Hz and 0.3 Hz), and ion density of this cell were measured, and the results were 6.0 °, 97.5%, 84.8%, and 248 pC. Moreover, the retardation value of the glass substrate in which the orientation film before cell assembly was formed was 0.13 nm.

EXAMPLE 23

A liquid crystal display device was manufactured in the same manner as in Example 1 except that varnish P was used instead of varnish A. At this time, instead of the liquid crystal composition A, the following liquid crystal composition B was enclosed in the cell. The pretilt angle, VHR (30 Hz and 0.3 Hz), and ion density of this cell were measured, and the results were 98.2 °, 99.3%, 92.1%, and 52 pC. When the cell was subjected to polarization microscopy under cross nicol, streaks of light omission resulting from rubbing were observed slightly, but in good orientation.

<Liquid crystal composition B>

[Example 24]

A liquid crystal display device was produced in the same manner as in Example 20 except that varnish Q was used instead of varnish P. The pretilt angle, VHR (30 Hz and 0.3 Hz), and ion density of this cell were measured, and found to be 98.0 °, 99.0%, 90.6%, and 89 pC. When the cell was subjected to polarization microscopy under cross nicol, streaks of light omission resulting from rubbing were observed slightly, but in good orientation.

[Comparative example 4]

A liquid crystal display device was manufactured in the same manner as in Example 23 except that varnish W was used instead of varnish P. The pretilt angle, VHR (30 Hz and 0.3 Hz) and ion density of this cell were measured, and the results were 98.3 °, 98.5%, 87.3%, and 186 pC.

When the cell was observed under a polarized microscope under cross nicol, compared with Example 23 or Example 24, there were many streaks of light omission resulting from rubbing, which was in a bad state.

The liquid crystal aligning agent of this invention can be used for the oriented film for liquid crystal display elements. Since the alignment film obtained from the liquid crystal aligning agent of this invention has high liquid crystal aligning property, it is especially useful for IPS mode, TN mode, and VA mode which rub and use an alignment film.

Claims (14)

A composition containing at least one polymer selected from polyamic acid and derivatives thereof obtained by reacting a mixture of tetracarboxylic dianhydride and other tetracarboxylic dianhydride represented by formula (I) with diamine, wherein Based on the total amount of the mixture of the acid dianhydride, the ratio of the tetracarboxylic dianhydride represented by Formula (I) is 5-95 mol%, and the ratio of the other tetracarboxylic dianhydride is 5-95 Liquid crystal aligning agent which is mol%:

Here, X is a C2-C12 alkylene. The method of claim 1,
Other tetracarboxylic dianhydride is at least one of tetracarboxylic dianhydride represented by Formula (A-1)-Formula (A-46), and diamine is Formula (1-1)-Formula (1-3) , Liquid crystal aligning agent which is at least 1 diamine chosen from the diamine group represented by Formula (2), Formula (3), and Formula (4):

In formula (1-1), b is 0 or 1; arbitrary hydrogen in cyclohexylene may be substituted by methyl;
In formula (1-2), W ¹ is -CH ₂ -or -NH-:

X ¹ is a single bond or alkylene having 1 to 10 carbon atoms; and any -CH ₂ -of this alkylene is -O-, -S-, -NH-, -N (CH ₃ )-,- Substituted by C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -SO _2- , 1,3-phenylene, 1,4-phenylene or piperazine-1,4-diyl May be;

In formula (3), X <^2> is single-bond, -O-, -COO-, -OCO-, or C1-C6 alkylene; R <^1> is C3-C30 alkyl or Formula (a) It is group to represent;
In formula (a), X ³ and X ⁴ are independently a single bond or alkylene having 1 to 4 carbon atoms; ring B and ring C are independently 1,4-phenylene or 1,4-cyclohexylene R ² and R ³ are independently fluorine or methyl, f and g are independently 0, 1 or 2; c, d and e are independently 0 or 1, and the sum thereof is 1 to 3; R ⁴ is alkyl of 1 to 30 carbon atoms, alkoxy of 1 to 30 carbon atoms, alkoxyalkyl or cholesteryl group of 2 to 30 carbon atoms, and in these alkyl, alkoxy and alkoxyalkyl, arbitrary hydrogen may be substituted with fluorine:

X ⁵ is independently —O— or alkylene having 1 to 6 carbon atoms; j is 0 or 1; R ⁵ is hydrogen, alkyl having 2 to 12 carbon atoms or alkoxy having 2 to 12 carbon atoms; ring T Is 1,4-phenylene or 1,4-cyclohexylene; X ⁶ is a single bond or alkylene having 1 to 3 carbon atoms; h is 0 or 1; The method of claim 2,
Other tetracarboxylic dianhydride is formula (A-1)-formula (A-4), formula (A-11), formula (A-12), formula (A-14), and formula (A-18) Formula (A-21), Formula (A-28), Formula (A-30), Formula (A-32), Formula (A-37), Formula (A-39) to Formula (A-41), and It is at least one of tetracarboxylic anhydride represented by Formula (A-43)-Formula (A-46), and diamine is Formula (1-2-1), Formula (1-3), Formula (2-1)- Formula (2-3), Formula (2-7), Formula (2-10) to Formula (2-27), Formula (2-29), Formula (2-37) to Formula (2-39), Formula (2-41), formula (2-43) to formula (2-47), formula (2-51), formula (3-1) to formula (3-12), and formula (4-1) to formula ( Liquid crystal aligning agent which is at least one of diamine represented by 4-12):

R ²⁰ is alkyl having 5 to 16 carbons, R ²¹ is alkyl having 3 to 10 carbons, and R ²² is alkyl or cholesteryl group having 6 to 16 carbons;

R ²⁶ is alkyl having 4 to 7 carbons here. The method of claim 3, wherein
Other tetracarboxylic dianhydride is formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20) At least tetracarboxylic anhydride represented by formula (A-21), formula (A-28), formula (A-30), formula (A-37), formula (A-40) and (A-45). One, diamine is formula (1-2-1), formula (1-3), formula (2-7), formula (2-10)-formula (2-12), formula (2-16)-formula (2-19), formula (2-21) to formula (2-27), formula (2-37) to formula (2-39), formula (2-41), formula (2-43) to formula ( 2-47), a liquid crystal aligning agent which is at least one of diamine represented by Formula (2-51), Formula (3-1)-Formula (3-12), and Formula (4-1)-Formula (4-12). The method of claim 4, wherein
Tetracarboxylic dianhydride in which other tetracarboxylic dianhydride is represented by Formula (A-1), Formula (A-12), Formula (A-14), Formula (A-18), and Formula (A-45). Diamine is at least one of formula (1-2-1), formula (1-3), formula (2-7), formula (2-10) to formula (2-12), and formula (2-26) , At least one of diamine represented by formula (2-44), formula (2-45) and formula (3-1) to formula (3-6). The method of claim 3, wherein
Other tetracarboxylic dianhydride is formula (A-14), formula (A-18), formula (A-19), formula (A-20), formula (A-21), formula (A-28) , Formula (A-29), formula (A-30), formula (A-32), formula (A-39), formula (A-40), formula (A-41), formula (A-43), It is at least one of the tetracarboxylic anhydride represented by Formula (A-44) and Formula (A-46), and diamine is Formula (1-2-1), Formula (1-3), Formula (2-1)- Formula (2-3), formula (2-26), formula (2-29), formula (2-37), formula (2-43) to formula (2-47), formula (3-1) to formula Liquid crystal aligning agent which is at least one of diamine represented by (3-12) and Formula (4-1)-Formula (4-12). The method according to claim 6,
Other tetracarboxylic dianhydrides are formula (A-14), formula (A-20), formula (A-21), formula (A-39), formula (A-44) and formula (A-46) It is at least one of tetracarboxylic anhydride shown, and a diamine is Formula (1-2-1), Formula (1-3), Formula (2-1)-Formula (2-3), Formula (2-26) , At least one of diamine represented by formula (2-29), formula (2-44) and formula (3-1) to formula (3-6). The method of claim 3, wherein
Other tetracarboxylic dianhydride is formula (A-1), formula (A-2), formula (A-3), formula (A-4), formula (A-11), formula (A-12) And at least one of tetracarboxylic anhydride represented by formula (A-45), wherein diamine is formula (1-2-1), formula (1-3), formula (2-1) to formula (2-3) , Formula (2-13) to formula (2-15), formula (2-20) to formula (2-26), formula (2-29), formula (2-39) and formula (2-41) The liquid crystal aligning agent which is at least one of the diamine shown. The method of claim 8,
Tetracarboxylic dianhydride in which other tetracarboxylic dianhydride is represented by Formula (A-1), Formula (A-2), Formula (A-4), Formula (A-12), and Formula (A-45). It is at least one of, and diamine is a formula (1-2-1), a formula (1-3), a formula (2-1)-a formula (2-3), a formula (2-13)-a formula (2-15) , At least one of diamine represented by formula (2-26) and formula (2-29). The method according to any one of claims 1 to 9,
The liquid crystal aligning agent which further contains at least 1 polymer chosen from other polyamic acid and its derivative (s) manufactured without using tetracarboxylic dianhydride represented by Formula (I). The liquid crystal aligning film formed by heating the coating film of the liquid crystal aligning agent in any one of Claims 1-9. The liquid crystal aligning film formed by heating the coating film of the liquid crystal aligning agent of Claim 10. The liquid crystal display element which has a pair of board | substrates, the liquid crystal layer formed between this board | substrate, the electrode which applies a voltage to a liquid crystal layer, and the liquid crystal aligning film of Claim 11. The liquid crystal display element which has a pair of board | substrates, the liquid crystal layer formed between this board | substrate, the electrode which applies a voltage to a liquid crystal layer, and the liquid crystal aligning film of Claim 12.