KR101878518B1 - Liquid crystal aligning agent suitable for photo-alignment process, and liquid crystal alignment film using same - Google Patents

Abstract

A liquid crystal alignment film which suppresses burn-in due to AC driving generated in an IPS driving method or an FFS driving type liquid crystal display device and which can alleviate the residual charges accumulated by the DC voltage, and a photo alignment treatment method for obtaining the liquid crystal alignment film A liquid crystal aligning agent suitable for use.
At least one diamine selected from the group consisting of a tetracarboxylic acid dianhydride having a specific structure having a cyclobutane skeleton and a structure represented by the following formulas (D-1) and (D-2) At least one polymer (component (A)) selected from a polyamic acid obtained by reaction of a diamine compound having an amino group protected by a thermally cleavable group and its imidized polymer, a tetracarboxylic acid dianhydride, (B) component selected from a polyamic acid obtained by a reaction of a diamine compound containing a diamine having an aromatic heterocyclic ring having a nitrogen atom and an imidized polymer thereof (component (B)), and an organic solvent , A liquid crystal aligning agent suitable for the photo-alignment treatment method.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal aligning agent suitable for a photo-alignment treatment method, and a liquid crystal alignment film using the same,

The present invention relates to a liquid crystal aligning agent for producing a liquid crystal alignment film, and a liquid crystal alignment film obtained from the liquid crystal aligning agent. More specifically, the present invention relates to a liquid crystal aligning agent which is suitable for forming a liquid crystal alignment film capable of imparting liquid crystal aligning ability by irradiation with polarized ultraviolet rays, and a liquid crystal alignment agent which is obtained from such a liquid crystal aligning agent .

In a liquid crystal display element used for a liquid crystal television, a liquid crystal display, or the like, a liquid crystal alignment film for controlling the alignment state of the liquid crystal is usually formed in the element.

At present, according to the most industrially popular method, this liquid crystal alignment film is formed by laminating the surface of a polyamic acid film formed on an electrode substrate and / or a polyimide film obtained by imidizing the polyamic acid film with a cloth such as cotton, nylon, Rubbing in one direction, so-called rubbing treatment.

The rubbing treatment of the film surface in the alignment process of the liquid crystal alignment film is an industrially useful method which is simple and excellent in productivity. However, the demand for higher performance, higher definition, and larger size of liquid crystal display elements is further increased. In the case of rubbing treatment, scratches, oscillations, effects due to mechanical force or static electricity on the surface of the resulting alignment film, Various problems such as in-plane nonuniformity have become apparent.

As a method for replacing the rubbing treatment, there is known a photo alignment method in which a liquid crystal aligning ability is imparted by irradiating polarized ultraviolet rays. The liquid crystal alignment treatment by the photo alignment method has been proposed by using a photoisomerization reaction, a photo-crosslinking reaction or a photo-decomposition reaction (see Non-Patent Document 1). Further, in Patent Document 1, it has been proposed to use a polyimide film having an alicyclic structure such as a cyclobutane ring in the main chain for the photo alignment method. When used in an alignment film for photo-alignment using polyimide, its usefulness is expected in that it has higher heat resistance than the other.

The optical alignment method is an advantage of being able to be produced by a manufacturing process that is industrially easy as a rubbing-less alignment treatment method. In addition, in a liquid crystal display device of IPS driving method or fringe field switching (hereinafter, FFS) driving method, The use of the liquid crystal alignment film obtained by the photo alignment method can improve the contrast of the liquid crystal display element and the viewing angle characteristics compared with the liquid crystal alignment film obtained by the rubbing treatment method and improve the performance of the liquid crystal display element. Has attracted attention as an alignment treatment method.

In addition to the basic characteristics such as excellent liquid crystal alignability and electrical characteristics, liquid crystal alignment films used in liquid crystal display devices of the IPS drive method and the FFS drive method are required to have an AC drive It is necessary to suppress the burn-in by the DC voltage and also to have characteristics such as fast relaxation of the residual charge accumulated by the DC voltage. However, the liquid crystal alignment film obtained by the photo alignment method has insufficient alignment control power of liquid crystal, electric characteristics as a liquid crystal display element, and stability of these characteristics, and it is difficult to satisfy the above characteristics.

Japanese Patent Application Laid-Open No. 9-297313

 &Quot; Liquid crystal photo alignment layer " Kidowaki, Ichimura functional material Nov. 1997, Vol.17, No.11, 13-22

The present invention relates to a liquid crystal alignment film capable of suppressing afterimage due to AC driving generated in an IPS driving method or an FFS driving type liquid crystal display device and capable of alleviating residual charges accumulated by a direct current voltage and a method for obtaining a liquid crystal alignment film And a liquid crystal aligning agent suitable for the photo-alignment treatment method.

In order to achieve the above-described object, the present inventors have found that a liquid crystal alignment component (hereinafter also referred to as a liquid crystal alignment component) having excellent liquid crystal alignability and strong alignment control force of liquid crystal and a component (hereinafter, (Hereinafter also referred to as " charge relaxation component ").

However, such a liquid crystal aligning agent does not always solve the above problems. That is, in the liquid crystal alignment film obtained from the liquid crystal aligning agent containing the above two components, afterimage generated by AC driving is generated even when the accumulated residual electric charge accumulated by the DC voltage is accelerated, It does not.

In order to achieve the above object, the present inventors have conducted intensive studies and found that tetracarboxylic acid dianhydride having a specific structure having a cyclobutane skeleton, p-phenylenediamines, and hydrogen At least one polymer selected from a polyamic acid comprising a polyamic acid obtained by reaction of a diamine containing a specific diamine having a diamine having an amino group protected by a substituted thermal depolarizing group and an imidated polymer thereof, And a polyamic acid comprising a polyamic acid obtained by reaction of a tetracarboxylic acid dianhydride and a diamine compound containing a diamine having an aromatic heterocyclic ring having a nitrogen atom as a charge relaxation component and an imidized polymer thereof, The use of polymers of the species and the incorporation of these components And that the above object can be achieved by the liquid crystal aligning agent.

Thus, the present invention provides the following.

1. A liquid crystal aligning agent comprising the following components (A), (B), and an organic solvent.

(A): at least one diamine selected from the group consisting of a tetracarboxylic acid dianhydride represented by the following formula (1) and a structure represented by the following formula (D-1) and (D-2) A polyamic acid obtained from a diamine represented by the following formula (2) and an imidized polymer thereof.

[Chemical Formula 1]

(In the formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group or alkynyl group having 2 to 6 carbon atoms, They may be the same or different)

(In the formula (2), A ₁ is at least a group selected from the group consisting of a single bond, -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O- and -OCO- Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R ₅ is a hydrogen atom or a divalent organic group having 1 to 8 carbon atoms; )

(2)

(In the formula (D-2), Z ₁ represents a single bond, an ester bond, an amide bond, a thioester bond, or a divalent organic group having 2 to 6 carbon atoms)

Component (B): at least one polymer selected from a polyamic acid obtained from a tetracarboxylic acid dianhydride and a diamine compound containing a diamine represented by the following formula (3), and an imidized polymer thereof.

(3)

(In the formula (3), B ₁ represents at least one kind selected from the group consisting of -O-, -NQ ² -, -CONQ ² -, -NQ ² CO-, -CH ₂ O- and -OCO- B ₂ is a single bond or an alkylene group having 1 to 4 carbon atoms, B ₃ is a nitrogen-containing heterocyclic ring, n is an integer of 1 to 4, and Q ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, B ₂ is a single bond, It is an integer of 4.)

Wherein the content ratio of the component (A) to the component (B) is 3/7 to 7/3 in terms of a mass ratio (A / B) and the content of the component (A) (B) and 1 to 10% by weight based on the total amount of the organic solvent.

3. The method of claim 1 wherein the tetracarboxylic acid dianhydride of component (A) is 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracar Wherein the tetracarboxylic acid dianhydride is at least one tetracarboxylic acid dianhydride selected from a tetracarboxylic acid dianhydride and a tetracarboxylic dianhydride.

4. The liquid crystal aligning agent according to any one of 1 to 3 above, wherein the tetracarboxylic acid dianhydride of component (A) is 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride .

5. The liquid crystal aligning agent according to any one of 1 to 4 above, wherein the diamine of the component (A) is a diamine containing the diamine represented by the formula (2) in an amount of 5 to 30 mol% based on the total diamine of the component (A).

6. The liquid crystal display device according to any one of 1 to 5 above, wherein the diamine represented by the formula (2) contained in the component (A) is at least one selected from the following formulas (DA-1) to (DA- Orientation agent.

7. The liquid crystal aligning agent according to any one of 1 to 6 above, wherein the diamine of the component (B) is a diamine containing the diamine represented by the formula (3) in an amount of 30 to 100 mol% based on the total diamine of the component (B).

8. The liquid crystal display device according to any one of 1 to 7 above, wherein the diamine represented by the formula (3) contained in the component (B) is at least one selected from the following formulas (DB-1) to (DB- Orientation agent.

9. The tetracarboxylic acid dianhydride as the component (B) is a compound represented by the following formula (4), wherein the structure of X ₁ is at least one selected from the following structures, 4. The liquid crystal aligning agent according to any one of claims 1 to 3,

10. The method according to any one of claims 1 to 8, wherein the tetracarboxylic acid dianhydride of component (B) is selected from 1,2,3,4-butanetetracarboxylic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride The liquid crystal aligning agent according to any one of (1) to (9) above, which contains at least one tetracarboxylic acid dianhydride and has a content of 50 to 100 mol% with respect to the total tetracarboxylic acid dianhydride as the component (B).

11. The liquid crystal aligning agent according to any one of 1 to 10 above, wherein the tetracarboxylic acid dianhydride as the component (B) is 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride.

12. The liquid crystal aligning agent according to any one of 1 to 11 above, wherein the diamine of the component (B) is a diamine containing a carboxylic acid-containing diamine represented by the following formula (5), in addition to the diamine represented by the formula (3).

[Chemical Formula 4]

(In the formula (5), B ₃ is the same as B ₁ , B ₄ is a single bond or an alkylene group having 1 to 4 carbon atoms, and m is an integer of 1 to 4)

Wherein the diamine of the component (B) contains the diamine represented by the formula (3) and the diamine represented by the formula (5), and the total amount of the diamine is from 40 to 100 mol% The liquid crystal aligning agent according to any one of 1 to 12.

14. The liquid crystal aligning agent according to any one of 1 to 13 above, wherein the diamine represented by the formula (5) is at least one selected from the group consisting of 3,5-diaminobenzoic acid and 2,5-diaminobenzoic acid.

15. A liquid crystal alignment film obtained by applying and firing the liquid crystal aligning agent according to any one of 1 to 14 above.

16. A liquid crystal alignment film obtained by coating and firing the liquid crystal aligning agent according to any one of 1 to 14 above, and irradiating further polarized radiation.

17. An IPS driving type or FFS driving type liquid crystal display device comprising the liquid crystal alignment film according to the above 15 or 16.

According to the present invention, there is provided a liquid crystal alignment film capable of suppressing afterimage due to AC driving generated in an IPS driving method or an FFS driving type liquid crystal display device and capable of alleviating residual charges accumulated by a DC voltage, and a liquid crystal alignment film A novel liquid crystal aligning agent suitable for the photo-alignment treatment method is obtained.

The reason why the above effect is obtained in the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention is not necessarily clarified, but it is considered as follows.

Generally, it is known that when two components having different surface energies are blended, components with low surface energy are localized on the surface of the film, and components with high surface energy are localized in the interface between the film and the substrate. The component (A) of the liquid crystal aligning agent of the present invention is a polyamic acid having a low surface energy because it uses a t-butyl group having a low polarity and becomes a liquid crystal alignment component. On the other hand, since the charge relaxation component has a nitrogen-containing aromatic heterocyclic ring such as a pyridine ring, it becomes a polyamic acid having a higher surface energy than the liquid crystal alignment component. Thus, when the liquid crystal aligning agent of the present invention is applied and baked, the resulting film has a liquid crystal alignment film in which the liquid crystal alignment component is localized on the film surface, and the charge relaxation component is localized on the interface between the film and the substrate. butyl group, the internal structure of the film does not have such a structure as described above, and the charge relaxation component exists on the surface of the film. Therefore, the liquid crystal alignability deteriorates, The afterimage due to the exposure is generated.

However, in a bulky structure such as a t-butyl group, since the interaction between the liquid crystal and the alignment film is inhibited, the liquid crystal alignability is lowered. However, the t-butyl group contained in the liquid crystal alignment component of the present invention The t-butyl group is substituted by a hydrogen atom, so that the t-butyl group is not already present in the resulting liquid crystal alignment film. Therefore, the obtained liquid crystal alignment film has excellent liquid crystal alignability as in the case of using a polyamic acid having no bulky structure such as a t-butyl group.

Thus, in the surface layer of the liquid crystal alignment film obtained in the present invention, a liquid crystal alignment component having excellent liquid crystal alignability is unevenly distributed, and a charge relaxation component that is fast in relaxation of the residual charge accumulated by the DC voltage exists in the inside of the film and at the electrode interface And therefore, it is considered to have excellent properties.

≪ Component (A) >

The component (A) contained in the liquid crystal aligning agent of the present invention is preferably a tetracarboxylic acid dianhydride having a cyclobutane ring represented by the following formula (1) and a tetracarboxylic acid dianhydride represented by the following formulas (D-1) and , And a diamine compound containing a diamine having a t-butoxycarbonyl group, which is a protecting group of an amino group substituted with a hydrogen atom by heating represented by the following formula (2), and a diamine compound containing a diamine having a tert- At least one kind of polymer selected from the polyamic acid obtained by the reaction and the imidized polymer thereof.

[Chemical Formula 5]

R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group or alkynyl group having 2 to 6 carbon atoms, or a phenyl group, They may be the same or different.

When R ₁ , R ₂ , R ₃ , and R ₄ have a three-dimensionally bulky structure, they deteriorate the liquid crystal alignability. Therefore, R ₁ , R ₂ , R ₃ and R ₄ are preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group.

Specific examples of the tetracarboxylic acid dianhydride having a cyclobutane ring represented by the above formula (1) include the following formulas (1-1) to (1-5). (1-1) and (1-2) are more preferable, and (1-2) is more preferable from the viewpoint of liquid crystal alignability.

[Chemical Formula 6]

In the formula (D-2), Z ₁ is a single bond, an ester bond, an amide bond, a thioester bond, or a divalent organic group having 2 to 4 carbon atoms.

In the Z ₁ , the ester bond is represented by -C (O) O-, or -OC (O) -. The amide bond may represent a structure represented by -C (O) NH-, or -C (O) NR-, -NHC (O) - or -NRC (O) -. R is an alkyl group having 1 to 4 carbon atoms.

Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a t-butyl group.

When Z ₁ is an organic group having 2 to 4 carbon atoms, it may be represented by the following formula (D2).

(7)

-Z ₄ -R ₆ -Z ₅ - (D 2)

Z ₄ and Z ₅ in the formula (D-2) are each independently a single bond or a group selected from the group consisting of -O-, -S-, -NR ₁₁ -, ester bond, amide bond, thioester bond, urea bond , Carbonate bond, carbamate bond. R ₁₁ is a hydrogen atom or a methyl group.

Z ₄ , Z ₅ and Z ₆ , ester bonds, amide bonds, and thioester bonds may represent the same structure of the above ester bond, amide bond and thioester bond.

The urea bond may represent a structure represented by -NH-C (O) NH-, or -NR-C (O) NR-. R is an alkyl group having 1 to 3 carbon atoms, and examples of the alkyl group include the same.

The carbonate bond may represent a structure represented by -O-C (O) -O-.

The carbamate bond includes a structure represented by -NH-C (O) -O-, -OC (O) -NH-, -NR-C (O) -O-, or -OC Lt; / RTI > R is an alkyl group having 1 to 4 carbon atoms, and examples of the alkyl group include the same.

R ₆ in the formula (D-2) is independently selected from the group consisting of a single bond, an alkylene group having 1 to 4 carbon atoms, an alkenylene group, an alkynylene group, an arylene group, and a combination thereof.

Examples of the alkylene group include a methylene group, a 1,1-ethylene group, a 1,2-ethylene group, a 1,2-propylene group, a 1,3-propylene group, And the like.

Examples of the alkenylene group include a 1,1-ethenylene group, a 1,2-ethenylene group, a 1,2-ethenylene methylene group, a 1-methyl-1,2-ethenylene group, , A 1-ethylene group, and a 1,2-ethenylene-1,2-ethylene group.

Examples of the alkynylene group include an ethynylene group, an ethynylene methylene group, an ethynylene-1,1-ethylene group, and an ethynylene-1,2-ethylene group.

Examples of the arylene group include a 1,2-phenylene group, a 1,3-phenylene group and a 1,4-phenylene group.

In the case where the structure of the diamine is a linear structure or a rigid structure, a liquid crystal alignment film having good liquid crystal alignability can be obtained. Therefore, as the structure of Z ₁ , a single bond or a structure represented by the following formulas (A1-1) to -18) is more preferable.

[Chemical Formula 8]

(D-1) and (D-2), since a liquid crystal orientation film having excellent liquid crystal alignability can be obtained as the diamine structure has a high linearity or a rigid structure. Diamines represented by the formula (D-1) or diamines represented by the following formulas (D2-1) to (D2-7) are more preferable, and diamines represented by the formula (D-1) desirable.

[Chemical Formula 9]

In the formula (2), A ₁ is a single bond or a group selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O- and -OCO- At least one divalent organic group or an alkylene group having 1 to 3 carbon atoms, wherein Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ₅ is a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms.

When Q ¹ is a bulky structure, the liquid crystal alignability is deteriorated. Therefore, Q ¹ is preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group.

As A ₁ , a single bond or an alkylene group having 1 to 3 carbon atoms is preferable, and a single bond or a methylene group or an ethylene group is more preferable.

Specific examples of the monovalent organic group having 1 to 8 carbon atoms in R ₅ include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a hexyl group, an octyl group, a cyclopentyl group, A cyclohexyl group, and the like; a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 2-butenyl group, a 1,3-butadienyl group, a 2-pentenyl group, (R-1) to (R-2) shown below, or an alkenyl group such as a methyl group, an ethyl group, And a structure having a thermally-cleavable group substituted with a hydrogen atom by heating as shown in Fig.

Even in the case of R ₅ , if the structure has a volume as large as Q ¹ , the liquid crystal alignability is deteriorated. Therefore, R ₅ is preferably a hydrogen atom, a methyl group, an ethyl group, and (R-1) or (R-2) ) Is more preferable.

[Chemical formula 10]

Specific examples of the diamine represented by the formula (2) include diamines of the following formulas (DA-1) to (DA-3). (DA-1) or (DA-2) is preferable, and (DA-1) is more preferable from the viewpoint of liquid crystal alignability.

(11)

In the component (A) contained in the liquid crystal aligning agent of the present invention, the higher the ratio of p-phenylenediamine in the diamine compound used is, the better the liquid crystal alignability and the stronger the interaction with the liquid crystal molecules. It is possible to reduce the afterimage generated by the exposure apparatus. On the other hand, the higher the proportion of the diamine represented by the formula (2) in the diamine compound, the lower the surface energy of the component (A), and the component (A) tends to be localized on the surface of the film.

In view of the above, the content of the p-phenylenediamine forming the component (A) used in the present invention is preferably 70 to 95 mol%, more preferably 80 to 95 mol%, and most preferably 90 To 95 mol% is more preferable. On the other hand, the content of the diamine represented by the above formula (2) is preferably from 30 to 5 mol%, more preferably from 20 to 5 mol%, still more preferably from 10 to 5 mol%, of the diamine compound.

≪ Component (B) >

The component (B) contained in the liquid crystal aligning agent of the present invention is a polyamic acid obtained from a tetracarboxylic acid dianhydride represented by the following formula (6) and a diamine compound containing a diamine represented by the following formula (3) And at least one kind of polymer selected from hydrogenated polymers.

[Chemical Formula 12]

In formula (3), B ₁ represents at least one kind selected from the group consisting of -O-, -NQ ² -, -CONQ ² -, -NQ ² CO-, -CH ₂ O-, and -OCO- Wherein Q ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Q ² includes a preferred example, and the same structure as Q ¹ can be given. B ₂ is a single bond or an alkylene group having 1 to 4 carbon atoms, B ₃ is a nitrogen-containing heterocyclic ring, and n is an integer of 1 to 4.

As B ₁ , a structure having a high polarity is preferable and a -O-, -NQ ² -, -CONQ ² -, and -OCO- are more preferable since the surface energy of the component (B) can be increased. As B ₂ , an alkylene group having 1 to 4 carbon atoms, preferably 1 or 2 carbon atoms is preferable for ease of synthesis.

Specific examples of the nitrogen atom-containing aromatic heterocyclic ring of B ₃ include a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, a triazole ring, a pyrazine ring, A benzoimidazole ring, and the like. A pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, or a pyrimidine ring is more preferable, and an imidazole ring, a pyridine ring, or a pyrimidine ring is more preferable from the viewpoint of availability of raw materials.

Specific examples of the diamine having a nitrogen atom-containing aromatic heterocyclic ring represented by the formula (3) include the following formulas (DB-1) to (DB-6).

The content of the diamine having a nitrogen atom-containing aromatic heterocyclic ring represented by the formula (3) is preferably 30 to 100 mol%, more preferably 40 to 100 mol%, and still more preferably 50 to 100 mol% ㏖%.

[Chemical Formula 13]

In the formula (6), X is a tetravalent organic group and its structure is not particularly limited. Specific examples thereof include structures of the following formulas (X-1) to (X-46). From the viewpoint of the availability of the compound, the structure of X may be X-1, X-2, X-3, X-4, X-5, X-6, X-8, X- 19, X-21, X-25, X-26, X-27, X-28, X-32 or X-46. It is preferable to use a tetracarboxylic acid dianhydride having an aliphatic or aliphatic cyclic structure because the resulting liquid crystal alignment film has improved transparency. The structure of X is preferably X-1, X-2, or X-25 And X-1 is more preferable from the viewpoint of reactivity with a diamine.

When X in the formula (6) contains a tetracarboxylic acid dianhydride represented by X-1, X-2, or X-25 in the tetracarboxylic acid dianhydride of the component (B) It is preferable that it contains 50 to 100 mol% of the carboxylic acid dianhydride. More preferably from 70 to 100 mol%, and still more preferably from 80 to 100 mol%.

[Chemical Formula 14]

[Chemical Formula 15]

[Chemical Formula 16]

[Chemical Formula 17]

When the component (B) contained in the liquid crystal aligning agent of the present invention is a liquid crystal alignment film by using a diamine compound having a carboxylic acid represented by the following formula (5) in addition to the diamine represented by the formula (3) It is possible to further alleviate the accumulated residual charge due to the DC voltage. Further, by using the diamine compound represented by the following formula (5), the surface energy of the component (B) becomes higher, the component (A) is localized by the film surface, and the component (B) Can be ubiquitous.

[Chemical Formula 18]

In formula (5), B ₃ has the same definition as B ₁ in the formula (3) and is a single bond, -O-, -NQ ³ -, -CONQ ³ -, -NQ ³ CO-, -CH ₂ O-, and -OCO-, wherein Q ³ includes a preferable example, and the same structure as Q ¹ can be given. B ₄ is a single bond or an alkylene group having 1 to 4 carbon atoms, and m is an integer of 1 to 4.

B ₃ is preferably a structure having a high polarity and more preferably a single bond, -CONQ ² -, or -OCO- because the surface energy of the component (B) can be increased.

Specific examples of the diamine having a carboxylic acid represented by the above formula (5) include 3,5-diaminobenzoic acid and 2,5-diaminobenzoic acid.

The diamine forming the component (B) preferably contains both a diamine represented by the formula (3) and a diamine represented by the formula (5). When containing both the diamine represented by the above formula (3) and the diamine represented by the above formula (5), the total content of these diamines is preferably from 40 to 100 mol%, more preferably from 50 to 100 mol% , More preferably from 60 to 100 mol%.

As the diamine component of the component (B), a diamine other than the above-mentioned formula (3) and the above-mentioned formula (5) may contain a diamine represented by the following formula (7). In the formula, Y ₁ is a divalent organic group and its structure is not particularly limited. Specific examples of Y ₁ include structures of the following formulas (Y-1) to (Y-75).

[Chemical Formula 19]

H ₂ NY ₁ -NH ₂ (7)

[Chemical Formula 20]

[Chemical Formula 21]

[Chemical Formula 22]

(23)

≪ EMI ID =

(25)

(26)

(27)

(28)

[Chemical Formula 29]

(30)

(31)

In order to improve the solubility of the component (B) of the liquid crystal aligning agent of the present invention in an organic solvent, examples of the structure of Y ₁ include Y-8, Y-20, Y-21, Y-22, -29, and Y-30.

There is a possibility that the orientation of the liquid crystal is disturbed if the polyamic acid of the component (B) is localized on the surface of the film. Therefore, the surface energy of the component (B) , It is preferable to use a diamine having a substituent having a high polarity. As the diamine having a substituent having a high polarity, a diamine containing a secondary or tertiary amino group, a hydroxyl group, an amide group or a urea group is preferable. Therefore, as Y _{1 in the} above formula (7), Y-19, Y-31, Y-40, Y-45, Y-49 to Y-51 or Y-61 are more preferable.

<Production method of polyamic acid>

The polyamic acid of the present invention can be obtained by the reaction of a tetracarboxylic acid dianhydride with a diamine.

Specifically, the tetracarboxylic acid dianhydride and the diamine are reacted in the presence of an organic solvent at -20 ° C to 150 ° C, preferably 0 ° C to 50 ° C for 30 minutes to 24 hours, preferably 1 to 12 hours And then synthesized.

The organic solvent used in the reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone or? -Butyrolactone from the solubility of the monomer and the polymer, May be mixed and used. The concentration of the polymer is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that the precipitation of the polymer does not occur well and a high molecular weight polymer is easily obtained.

The polyamic acid thus obtained can be recovered by precipitating the polymer by injecting the reaction solution into a poor solvent with good stirring. It is also possible to obtain a purified polyamic acid powder by conducting precipitation several times, washing with a poor solvent, and then drying at room temperature or by heating. Examples of the poor solvent include, but are not limited to, water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

<Production method of polyimide>

The imidized polymer (polyimide) of the polyamic acid used in the present invention can be prepared by imidizing the polyamic acid.

When a polyimide is produced from polyamic acid, chemical imidization by adding a catalyst to a solution of the polyamic acid obtained by the reaction of the diamine component and the tetracarboxylic acid dianhydride is simple. The chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the molecular weight of the polymer is not lowered in the process of imidization.

The chemical imidization can be carried out by stirring the polymer to be imidized in the presence of a basic catalyst and an acid anhydride in an organic solvent. As the organic solvent, a solvent used in the polymerization reaction described above may be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferred since it has a basicity suitable for proceeding the reaction. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like can be mentioned. Among them, acetic anhydride is preferable because the purification after completion of the reaction becomes easy.

The temperature at which the imidization reaction is carried out may be -20 ° C to 140 ° C, preferably 0 ° C to 100 ° C, and the reaction time may be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 molar times, preferably 2 to 20 molar times, and the amount of the acid anhydride is 1 to 50 molar equivalents, preferably 3 to 30 molar equivalents, of the amic acid group. The imidization rate of the resulting polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time.

Since the added catalyst remains in the solution after the imidation reaction of the polyamic acid ester or polyamic acid, the imidized polymer thus obtained is recovered and redissolved in an organic solvent to obtain the liquid crystal of the present invention It is preferable to use an orientation agent.

The solution of the polyimide obtained as described above can be precipitated by injecting into a poor solvent with good stirring. After several times of precipitation and washing with a poor solvent, the purified polyamic acid ester powder can be obtained at room temperature or by heating and drying.

Examples of the poor solvent include, but are not limited to, methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene and benzene.

<Liquid Crystal Aligner>

The liquid crystal aligning agent of the present invention has a form of a solution containing a component (A), a component (B) and an organic solvent, and the components (A) and (B) are dissolved in an organic solvent.

The molecular weight of the polyamic acid of the component (A) and the polyamic acid of the component (B) is preferably from 2,000 to 500,000, more preferably from 5,000 to 300,000, and still more preferably from 10,000 to 100,000. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 5,000 to 50,000.

In the liquid crystal aligning agent of the present invention, the ratio of the component (A) to the component (B) is preferably 3/7 to 7/3 in terms of the mass ratio of the component (A) / the component (B). This ratio is more preferably 4/6 to 6/4. By setting this ratio in this range, it is preferable to form a liquid crystal alignment film which suppresses the afterimage due to the AC drive and can alleviate the residual charge accumulated by the DC voltage.

The liquid crystal aligning agent of the present invention is not limited as long as the components (A) and (B) have the form of a solution dissolved in an organic solvent. For example, a method of mixing the component (A) and the powder of the component (B) and dissolving them in an organic solvent, a method of mixing a powder of the component (A) and a solution of the component (B) And a powder of the component (B), or a method of mixing a solution of the component (A) and a solution of the component (B). A method of mixing a solution of the component (A) and a solution of the component (B) is more preferable because a homogeneous mixed solution can be obtained even when the components (A) and (B) .

The concentration of the polymer of the liquid crystal aligning agent of the present invention can be appropriately changed depending on the setting of the thickness of the coating film to be formed, but it is preferably 1% by weight or more from the viewpoint of forming a uniform and defect- And more preferably 10 wt% or less.

The organic solvent contained in the liquid crystal aligning agent of the present invention is not particularly limited as long as the components (A) and (B) are uniformly dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl- , N-methylcaprolactam, 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethylsulfoxide, dimethylsulfone,? -Butyrolactone, 1,3-dimethyl- imidazolidinone, N, N-dimethylpropanamide, and the like. These may be used alone or in combination of two or more. Insofar as the solvent alone can not dissolve the polymer component uniformly, it may be mixed with the organic solvent as long as the polymer does not precipitate.

The liquid crystal aligning agent of the present invention may contain, in addition to the organic solvent for dissolving the polymer component, a solvent for improving the uniformity of the coating film when the liquid crystal aligning agent is applied to the substrate. Such a solvent generally uses a solvent having a lower surface tension than the organic solvent. Specific examples thereof include ethylcellosolve, butylcellosolve, ethylcarbitol, butylcarbitol, ethylcarbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy- 2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether- Propanol, lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-butyl ester, lactic acid, isoamyl acetate, Esters and the like. These solvents may be used in combination of two or more.

The liquid crystal aligning agent of the present invention may contain other components than the polymer of the component (A) and the component (B), such as the liquid crystal alignment film, to change electric characteristics such as the dielectric constant and conductivity of the liquid crystal alignment film A silane coupling agent for improving the adhesion between the liquid crystal alignment film and the substrate, a crosslinkable compound for increasing the hardness or density of the film when the film is used as a liquid crystal alignment film, and further, a polyamic acid An imidization accelerator for the purpose of efficiently promoting the imidization of the imidization accelerator may be added.

&Lt; Liquid crystal alignment film &

The liquid crystal alignment film of the present invention is a coating film obtained by applying the liquid crystal aligning agent thus obtained to a substrate, followed by drying and firing.

The substrate to which the liquid crystal aligning agent of the present invention is applied is not particularly limited as long as it is a substrate having high transparency and can be a glass substrate, a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, It is preferable from the viewpoint of simplification of the process. In the reflection type liquid crystal display device, an opaque material such as a silicon wafer can be used as long as it is a substrate on only one side. In this case, a material that reflects light such as aluminum can also be used as the electrode in this case. Examples of the application method of the liquid crystal aligning agent of the present invention include a spin coating method, a printing method, and an ink jet method.

The drying and firing steps after the application of the liquid crystal aligning agent of the present invention can be carried out at arbitrary temperature and time. Usually, it is dried at 50 to 120 ° C for 1 to 10 minutes to sufficiently remove the contained organic solvent, and then baked at 150 to 300 ° C for 5 to 120 minutes. The thickness of the coated film after firing is not particularly limited, but if it is too thin, the reliability of the liquid crystal display element may deteriorate. Therefore, it is 5 to 300 nm, preferably 10 to 200 nm.

The liquid crystal aligning agent of the present invention can be subjected to conventional rubbing alignment treatment, but is particularly useful when used in a photo alignment treatment method.

As a specific example of the photo-alignment treatment method, there is a method of irradiating the surface of the above coating film with polarized radiation in a predetermined direction and, if necessary, further heating treatment at a temperature of 150 to 250 ° C to give a liquid crystal aligning ability . As the wavelength of the radiation, ultraviolet rays and visible rays having a wavelength of 100 nm to 800 nm can be used. Of these, ultraviolet rays having a wavelength of 100 nm to 400 nm are preferable, and those having a wavelength of 200 nm to 400 nm are particularly preferable. Further, in order to improve the liquid crystal alignment property, the coated film substrate may be irradiated with radiation while heating at 50 to 250 ° C. The irradiation dose of the radiation is preferably in the range of 1 to 10,000 mJ / cm 2, and particularly preferably in the range of 100 to 5,000 mJ / cm 2.

The liquid crystal alignment film produced as described above can stably orient liquid crystal molecules in a certain direction.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Hereinafter, the abbreviations of the compounds used in this embodiment and the comparative examples and the measurement methods of the respective properties are as follows.

DA-1, DA-2, and DB-1: defined above.

NMP: N-methyl-2-pyrrolidone

BCS: butyl cellosolve

[Viscosity]

In the synthesis examples, the viscosity of the polyamic acid ester and the polyamic acid solution was 1.1 ml of a sample amount, the cone TE-1 (1 ° 34 ', R24), and the viscosity of the solution was measured using an E-type viscometer TVE-22H The temperature was measured at 25 캜.

[Molecular Weight]

The molecular weight of the polymer was measured by a GPC (room temperature gel permeation chromatography) apparatus to give a number average molecular weight (hereinafter also referred to as Mn) and a weight average molecular weight (hereinafter also referred to as Mw) as the values in terms of polyethylene glycol and polyethylene oxide .

GPC apparatus: manufactured by Shodex Corp. (GPC-101)

Column: manufactured by Shodex Co., Ltd. (serial of KD803, KD805)

Column temperature: 50 ° C

Eluent: N, N-dimethylformamide (30 m mol / l of lithium bromide-hydrate (LiBr.H ₂ O) as additive, 30 mmol / l of phosphoric acid anhydrous crystal (o-phosphoric acid) (THF) of 10 ml / l) Flow rate: 1.0 ml / min

Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (weight average molecular weight (Mw) of about 900,000, 150,000, 100,000 and 30,000) manufactured by Tosoh Corporation and polyethylene glycol (peak top molecular weight (Mp) of about 12,000 and 4,000 , 1,000). In order to avoid peaks overlapping, two samples of samples mixed with four types of 900,000, 100,000, 12,000 and 1,000 and three samples of 150,000, 30,000 and 4,000 were separately measured.

[AC drive burn-in characteristics of FFS driven liquid crystal cell]

An ITO electrode having a thickness of 50 nm in the form of an electrode was formed on the first layer, silicon nitride having a thickness of 500 nm in the form of an insulating film on the second layer, and a comb-shaped ITO electrode (electrode width: , A liquid crystal aligning agent was applied by spin coating to a glass substrate on which an electrode for driving Fringe Field Switching (hereinafter referred to as FFS) having an electrode pitch of 6 μm and an electrode height of 50 nm was formed Respectively. Dried on a hot plate at 80 DEG C for 5 minutes and then fired in a hot air circulating oven at 250 DEG C for 60 minutes to form a coating film having a thickness of 100 nm.

An ultraviolet ray having a wavelength of 254 nm was irradiated to the coated film surface via a polarizing plate to obtain a substrate having a liquid crystal alignment film formed thereon. A coating film was similarly formed on a glass substrate having a columnar spacer with a height of 4 占 퐉, on which no electrode was formed as a counter substrate, and alignment treatment was carried out.

A sealant was printed on the substrate using the above two substrates as a set and the other substrate was adhered so that the alignment direction of the liquid crystal alignment film face was 0 deg. Cells were prepared. A liquid crystal MLC-2041 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell.

The VT characteristic (voltage-transmittance characteristic) of this FFS-driven liquid crystal cell under a temperature of 58 캜 was measured, and then a square wave of 賊 4 V / 120 Hz was applied for 4 hours. After 4 h, it disconnects the voltage was calculated and then allowed to stand for 60 minutes, re-measures the VT characteristics, difference between the voltage square wave that is 50% of the transmittance before and after (ΔV ₅₀₎ at a temperature of 58 ℃.

[Charge relaxation characteristics]

The liquid crystal cell was placed on a light source, and the transmittance (T _a ) of the liquid crystal cell in a state in which a VT characteristic (voltage-transmittance characteristic) was measured and then a square wave of ± 1.5 V / 60 Hz was applied was measured. Thereafter, a square wave of ± 1.5 V / 60 Hz was applied for 10 minutes, and then 2 V of direct current was superimposed and driven for 180 minutes. Breaking the direct-current voltage, again with ± 1.5 V / 20 bun only rectangular wave of 60 Hz, 60 minutes, and the transmittance of the liquid crystal cell at the time sikyeoteul drive 90 minutes (T _b) of the respective measurement, the transmittance at each time (T _b) and from a difference (ΔT) of the initial transmittance (T _a) of yielding a difference in transmittance caused by a voltage remaining in the liquid crystal display device.

(Synthesis Example 1)

2.92 g (27.0 mmol) of p-phenylenediamine and 0.67 g (3.0 mmol) of DA-1 were taken in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 52.27 g of NMP was added , And dissolved with stirring while nitrogen was being supplied. While this diamine solution was stirred, 6.66 g (29.7 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride was added, and further NMP And the mixture was stirred at room temperature for 24 hours to obtain a solution of polyamic acid (PAA-1). The viscosity of this polyamic acid solution at 25 캜 was 680 mPa s. The molecular weight of the polyamic acid was Mn = 9,279 and Mw = 21,886.

(Synthesis Example 2)

2.60 g (24.0 mmol) of p-phenylenediamine and 1.34 g (6.0 mmol) of DA-1 were taken in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 52.65 g of NMP was added , And dissolved with stirring while nitrogen was being supplied. While this diamine solution was stirred, 6.59 g (29.4 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride was added, and NMP And the mixture was stirred at room temperature for 24 hours to obtain a solution of polyamic acid (PAA-2). The viscosity of this polyamic acid solution at 25 캜 was 357 mPa.. The molecular weight of the polyamic acid was Mn = 9,042 and Mw = 19,958.

(Synthesis Example 3)

1.94 g (17.9 mmol) of p-phenylenediamine and 0.44 g (1.97 mmol) of DA-1 were taken in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 49.86 g of NMP was added , And dissolved with stirring while nitrogen was being supplied. While stirring the diamine solution, 3.77 g (19.2 mmol) of 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride was added, NMP was further added so that the solid concentration became 10% by weight, Followed by stirring for 24 hours to obtain a solution of polyamic acid (PAA-3). The viscosity of this polyamic acid solution at 25 캜 was 142 mPa.. The molecular weight of the polyamic acid was Mn = 11,494 and Mw = 24,376.

(Synthesis Example 4)

3.181 g (28.8 mmol) of p-phenylenediamine and 0.85 g (3.20 mmol) of DA-2 were taken in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 51.89 g of NMP was added , And dissolved with stirring while nitrogen was being supplied. While stirring the diamine solution, 6.21 g (31.7 mmol) of 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride was added, NMP was further added so that the solid content concentration became 15% by weight, And stirred for 24 hours to obtain a solution of polyamic acid (PAA-4). The viscosity of this polyamic acid solution at 25 캜 was 10010 mPa s. The molecular weight of this polyamic acid was Mn = 21,525 and Mw = 58,007.

(Synthesis Example 5)

2.16 g (20.0 mmol) of p-phenylenediamine was added to a 100 ml four-necked flask equipped with a stirrer and a nitrogen-introducing tube, 52.02 g of NMP was added, and dissolved with stirring while nitrogen was being supplied. 4.43 g (19.8 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride was added while stirring the diamine solution, and NMP And the mixture was stirred at room temperature for 24 hours to obtain a solution of polyamic acid (PAA-5). The viscosity of this polyamic acid solution at 25 캜 was 89.1 mPa s. The molecular weight of the polyamic acid was Mn = 7,048 and Mw = 16,664.

(Synthesis Example 6)

2.16 g (20.0 mmol) of p-phenylenediamine was added to a 100 ml four-necked flask equipped with a stirrer and a nitrogen-introducing tube, 47.70 g of NMP was added, and dissolved with stirring while nitrogen was being supplied. While stirring the diamine solution, 3.84 g (19.6 mmol) of 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride was added, NMP was further added so that the solid concentration became 10% by weight, Followed by stirring for 24 hours to obtain a solution of polyamic acid (PAA-6). The viscosity of the polyamic acid solution at 25 캜 was 303 mPa.. The molecular weight of the polyamic acid was Mn = 19,188 and Mw = 49,182.

(Synthesis Example 7)

2.74 g (18.0 mmol) of 3,5-diaminobenzoic acid and 2.92 g (12.1 mmol) of DB-1 were taken in a 100 ml four-necked flask equipped with a stirrer and equipped with a nitrogen inlet tube and 58.77 g And the mixture was stirred to dissolve while nitrogen was being fed. 5.88 g (30.0 mmol) of 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride was added while stirring the diamine solution, NMP was further added so that the solid content concentration became 15% by weight, And stirred for 24 hours to obtain a solution of polyamic acid (PAA-7). The viscosity of this polyamic acid solution at 25 캜 was 256 mPa.. The molecular weight of the polyamic acid was Mn = 11,589 and Mw = 36,055.

(Synthesis Example 8)

9.13 g (60.0 mmol) of 3,5-diaminobenzoic acid and 9.69 g (40.0 mmol) of DB-1 were taken in a 300 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 55.83 g And the mixture was stirred to dissolve while nitrogen was being fed. While this diamine solution was stirred, 9.91 g (50.0 mmol) of 1,2,3,4-butanetetracarboxylic acid dianhydride was added, NMP was further added so that the solid concentration became 25% by weight, And stirred for 2 hours. After 2 hours, 10.69 g (49.0 mmol) of pyromellitic dianhydride was added to the polymerization solution, NMP was further added so that the solid concentration became 15% by weight, and the mixture was stirred at room temperature for 24 hours to obtain polyamic acid (PAA- 8) was obtained. The viscosity of this polyamic acid solution at 25 캜 was 860 mPa.. The molecular weight of the polyamic acid was Mn = 11,319 and Mw = 28,237.

(Synthesis Example 9)

1.83 g (12.0 mmol) of 3,5-diaminobenzoic acid and 1.93 g (7.97 mmol) of DB-1 were taken in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 12.33 g And the mixture was stirred to dissolve while nitrogen was being fed. 9.91 g (10.0 mmol) of 1,2,3,4-butanetetracarboxylic acid dianhydride was added while stirring the diamine solution, NMP was further added so that the solid concentration became 25% by weight, And stirred for 2 hours. After 2 hours, 3.06 g (9.99 mmol) of 3,3 ', 4,4'-bicyclohexyltetracarboxylic dianhydride was added to the polymerization solution, and NMP was further added thereto so that the solid content concentration became 20 wt% And the mixture was stirred at room temperature for 24 hours to obtain a solution of polyamic acid (PAA-9). The viscosity of this polyamic acid solution at 25 캜 was 760 mPa s. The molecular weight of this polyamic acid was Mn = 10,635 and Mw = 28,670.

(Synthesis Example 10)

3.66 g (24.0 mmol) of 3,5-diaminobenzoic acid and 3.88 g (16.0 mmol) of DB-1 were taken in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube. 57.56 g And the mixture was stirred to dissolve while nitrogen was being fed. 8.58 g (39.3 mmol) of pyromellitic dianhydride was added while stirring the diamine solution, NMP was further added so that the solid content concentration became 20% by weight, and the mixture was stirred at room temperature for 24 hours to obtain polyamic acid (PAA-10) &Lt; / RTI &gt; The viscosity of this polyamic acid solution at 25 캜 was 2221 mPa s. The molecular weight of the polyamic acid was Mn = 18,343 and Mw = 47,290.

(Example 1)

2.12 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 1 and 2.81 g of the polyamic acid solution (PAA-7) obtained in Synthesis Example 7, 5.04 g of NMP and 5.04 g of BCS Was added and the mixture was stirred for 30 minutes using a magnetic stirrer to obtain a liquid crystal aligning agent (A-1).

(Example 2)

3.41 g of the polyamic acid solution (PAA-2) obtained in Synthetic Example 2 and 5.22 g of the polyamic acid solution (PAA-7) obtained in Synthetic Example 7 were taken in a 50 ml sample tube equipped with a stirrer, 7.39 g of NMP, Was added thereto, and the mixture was stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (A-2).

(Example 3)

3.12 g of the polyamic acid solution (PAA-3) obtained in Synthesis Example 3 and 2.82 g of the polyamic acid solution (PAA-7) obtained in Synthesis Example 7 were taken in a 20 ml sample tube into which an agitator was placed, 4.09 g of NMP, And the mixture was stirred for 30 minutes using a magnetic stirrer to obtain a liquid crystal aligning agent (A-3).

(Example 4)

2.09 g of the polyamic acid solution (PAA-4) obtained in Synthetic Example 4 and 2.81 g of the polyamic acid solution (PAA-7) obtained in Synthetic Example 7 were taken in a 20 ml sample tube into which a stirrer was inserted, 5.11 g of NMP, Was added and the mixture was stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (A-4).

(Comparative Example 1)

8.52 g of the polyamic acid solution (PAA-2) obtained in Synthesis Example 2 was placed in a 50 ml sample tube equipped with a stirrer, 7.47 g of NMP and 3.99 g of BCS were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent B-1).

(Comparative Example 2)

12.39 g of the polyamic acid solution (PAA-5) obtained in Synthetic Example 5 was taken in a 50 ml sample tube equipped with a stirrer, 3.62 g of NMP and 4.07 g of BCS were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent B-2).

(Comparative Example 3)

5.96 g of the polyamic acid solution (PAA-6) obtained in Synthetic Example 6 was taken in a 50 ml sample tube equipped with a stirrer, 1.93 g of NMP and 1.98 g of BCS were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent B-3).

(Comparative Example 4)

4.96 g of the polyamic acid solution (PAA-5) obtained in Synthetic Example 5 and 5.22 g of the polyamic acid solution (PAA-7) obtained in Synthetic Example 7 were taken in a 50 ml sample tube equipped with a stirrer, 5.81 g of NMP, And the mixture was stirred for 30 minutes using a magnetic stirrer to obtain a liquid crystal aligning agent (B-4).

(Example 5)

ITO electrode having a film thickness of 50 nm as a first layer, silicon nitride having a film thickness of 500 nm as an insulating film as a second layer, ITO electrode (electrode width: 3 mu m, electrode spacing: : A liquid crystal aligning agent (A-1) obtained in Example 1 was filtered with a filter of 1.0 占 퐉 on a glass substrate provided with an FFS driving electrode having a thickness of 5 占 퐉 and a height of 50 占 퐉, Lt; / RTI &gt; Subsequently, the substrate was dried on a hot plate at 80 DEG C for 5 minutes, and then fired in a hot air circulating oven at 230 DEG C for 30 minutes to form a coating film having a thickness of 120 nm. This coated film surface was irradiated with ultraviolet rays of 254 nm through a polarizing plate at 500 mJ / cm 2 to obtain a substrate having a liquid crystal alignment film formed thereon. A coating film was similarly formed on a glass substrate having a columnar spacer with a height of 4 占 퐉, on which no electrode was formed as a counter substrate, and alignment treatment was carried out.

A sealant was printed on the substrate with two sets of the above substrates as one set and another substrate was adhered so that the alignment direction of the liquid crystal alignment film face was 0 °, Cells were prepared. A liquid crystal MLC-2041 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell.

The AC drive burn-in characteristics of this FFS-driven liquid crystal cell were evaluated. As a result,? V ₅₀ was 1.0 mV. As a result of evaluating the charge relaxation characteristics,? T after 20, 60, and 90 minutes of AC driving were 8%, 0%, and 0%, respectively.

(Example 6)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that polarized ultraviolet ray of 400 mJ / cm 2 was irradiated using the liquid crystal aligning agent (A-2) obtained in Example 2. The AC drive burn-in characteristics of this FFS-driven liquid crystal cell were evaluated. As a result,? V ₅₀ was 4.3 mV. As a result of evaluating the charge relaxation characteristics,? T after 20 minutes, 60 minutes, and 90 minutes of AC driving were 1.5%, 0%, and 0%, respectively.

(Example 7)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal aligning agent (A-3) obtained in Example 3 was used and irradiated with polarized ultraviolet rays of 750 mJ / cm 2. As a result of evaluating the AC drive burn-in characteristics of this FFS-driven liquid crystal cell, the difference in voltage having a transmittance of 50% before and after application of the square wave was 2.2 mV. As a result of evaluating the charge relaxation characteristics,? T after 20, 60, and 90 minutes of AC driving were 0%, 0%, and 0%, respectively.

(Example 8)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal aligning agent (A-4) obtained in Example 4 was used and 1000 mJ / cm 2 of polarized ultraviolet light was irradiated. As a result of evaluating the AC drive burn-in characteristics for this FFS-driven liquid crystal cell,? V ₅₀ was 3.6 mV. As a result of evaluating the charge relaxation characteristics,? T after 20, 60, and 90 minutes of AC driving were 0%, 0%, and 0%, respectively.

(Comparative Example 5)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal aligning agent (B-1) obtained in Comparative Example 1 was used and irradiated with polarized ultraviolet rays of 400 mJ / cm 2. As a result of evaluating the AC drive burn-in characteristics of this FFS-driven liquid crystal cell,? V ₅₀ was 3.5 mV. As a result of evaluating the charge relaxation characteristics,? T after 20, 60, and 90 minutes of AC driving were 0.6%, 0.3%, and 0.3%, respectively.

(Comparative Example 6)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal aligning agent (B-2) obtained in Comparative Example 2 was irradiated with polarized ultraviolet rays of 400 mJ / cm 2. The AC drive burn-in characteristics of this FFS-driven liquid crystal cell were evaluated. As a result,? V ₅₀ was 1.0 mV. As a result of evaluating the charge relaxation characteristics,? T after 20, 60, and 90 minutes of AC driving were 0.6%, 0.3%, and 0.4%, respectively.

(Comparative Example 7)

An FFS-driving liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal aligning agent (B-3) obtained in Comparative Example 3 was irradiated with polarized ultraviolet rays of 1000 mJ / cm 2. As a result of evaluating the AC drive burn-in characteristics of this FFS-driven liquid crystal cell,? V ₅₀ was 0.8 mV. As a result of evaluating the charge relaxation characteristics,? T after 20, 60, and 90 minutes of AC driving were 2.1%, 0.4%, and 0.1%, respectively.

(Comparative Example 8)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal aligning agent (B-4) obtained in Comparative Example 4 was used and irradiated with polarized ultraviolet rays of 400 mJ / cm 2. As a result of evaluating the AC drive burn-in characteristics of this FFS-driven liquid crystal cell,? V ₅₀ was 5.2 mV. As a result of evaluating the charge relaxation characteristics,? T after 20, 60, and 90 minutes of AC driving were 4%, 0%, and 0%, respectively.

As is apparent from Table 1, the results of Comparative Example 5 show that when the component (A) of the aligning agent of the present invention is used singly, the AC drive burn-in characteristics are good, but the accumulated charge is slow. On the other hand, the results of Examples 5 to 8 show that the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention exhibits an AC drive burn-in property almost equivalent to that of the component (A) alone, It was confirmed to be an alignment film.

On the other hand, from the results of Comparative Example 6 and Comparative Example 7, it was found that when the component (A) of the liquid crystal aligning agent of the present invention was used alone and the polyamic acid obtained without using the diamine represented by the formula (2) The driving burn-in characteristics are degraded, and the accumulated charges are slowed down. From the results of Comparative Example 8, when the component (B) was mixed as the charge relaxation component in the polyamic acid obtained without using the diamine represented by the formula (2) as the component (A) of the liquid crystal aligning agent, the charge relaxation property However, it was confirmed that the AC drive burn-in characteristics were greatly deteriorated.

(Example 9)

3.20 g of the polyamic acid solution (PAA-1) obtained in Synthetic Example 1 and 3.98 g of the polyamic acid solution (PAA-8) obtained in Synthetic Example 8 were taken in a 50 ml sample tube equipped with a stirrer, 8.85 g of NMP, Was added thereto, and the mixture was stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (A-5).

(Example 10)

3.22 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 1 and 3.77 g of the polyamic acid solution (PAA-9) obtained in Synthesis Example 9 were taken in a 50 ml sample tube into which an agitator was placed, 9.04 g of NMP, Was added thereto, and the mixture was stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (A-6).

(Example 11)

3.21 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 1 and 3.62 g of the polyamic acid solution (PAA-10) obtained in Synthesis Example 10 were taken in a 50 ml sample tube containing the stirrer, 9.28 g of NMP, And the mixture was stirred for 30 minutes using a magnetic stirrer to obtain a liquid crystal aligning agent (A-7).

(Example 12)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that the liquid crystal aligning agent (A-5) obtained in Example 9 was used and irradiated with polarized ultraviolet rays of 400 mJ / cm 2. As a result of evaluating the AC drive burn-in characteristics of this FFS-driven liquid crystal cell,? V ₅₀ was 0.9 mV.

(Example 13)

An FFS-driven liquid crystal cell was produced in the same manner as in Example 5 except that polarized ultraviolet light of 400 mJ / cm 2 was irradiated using the liquid crystal aligning agent (A-6) obtained in Example 10. As a result of evaluating the AC drive burn-in characteristics for this FFS-driven liquid crystal cell,? V ₅₀ was 1.5 mV.

(Example 14)

An FFS-driving liquid crystal cell was produced in the same manner as in Example 5 except that polarized ultraviolet ray of 400 mJ / cm 2 was irradiated using the liquid crystal aligning agent (A-7) obtained in Example 11. As a result of evaluating the AC drive burn-in characteristics of this FFS-driven liquid crystal cell,? V ₅₀ was 1.1 mV.

The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2010-234933 filed on October 19, 2010 are hereby incorporated herein by reference as the disclosure of the specification of the present invention.

Claims (18)

A liquid crystal aligning agent characterized by comprising a component (A), a component (B), and an organic solvent.
(A): at least one diamine selected from the group consisting of a tetracarboxylic acid dianhydride represented by the following formula (1) and a structure represented by the following formula (D-1) and (D-2) At least one polymer selected from a polyamic acid obtained by reaction of a diamine-containing diamine compound represented by the following formula (2) and an imidized polymer thereof.

(In the formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group or alkynyl group having 2 to 6 carbon atoms, or a phenyl group )
(In the formula (2), A ₁ represents a single bond or a group represented by -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O-, -OCO-, , Wherein Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ₅ is a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms to be.)

(In the formula (D-2), Z ₁ represents a single bond, an ester bond, an amide bond, a thioester bond, or a divalent organic group having 2 to 6 carbon atoms)
Component (B): at least one polymer selected from the group consisting of a polyamic acid obtained by reaction of a tetracarboxylic acid dianhydride with a diamine compound containing a diamine represented by the following formula (3), and an imidized polymer thereof.

(In the formula (3), B ₁ represents at least one kind selected from the group consisting of -O-, -NQ ² -, -CONQ ² -, -NQ ² CO-, -CH ₂ O- and -OCO- Q ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, B ₂ is a single bond, or an alkylene group having 1 to 4 carbon atoms, B ₃ is a nitrogen atom-containing heterocyclic ring, n Is an integer of 1 to 4.) The method according to claim 1,
Wherein the content ratio (A / B) of the component (A) to the component (B) is 3/7 to 7/3 and the total content of the component (A) ) Component, and an organic solvent in an amount of 1 to 10% by weight based on the total amount of the liquid crystal aligning agent. The method according to claim 1,
Wherein the tetracarboxylic acid dianhydride of component (A) is at least one selected from the group consisting of 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid And at least one tetracarboxylic acid dianhydride selected from dianhydrides. The method according to claim 1,
Wherein the tetracarboxylic acid dianhydride of component (A) is 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. The method according to claim 1,
Wherein the diamine compound of the component (A) is a diamine containing 5 to 30 mol% of a diamine represented by the formula (2). The method according to claim 1,
Wherein the diamine represented by the formula (2) contained in the component (A) is at least one selected from the following formulas (DA-1), (DA-2) and (DA-3).

The method according to claim 1,
Wherein the diamine compound of the component (B) is a diamine containing 30 to 100 mol% of a diamine represented by the formula (3). The method according to claim 1,
Wherein the diamine represented by the formula (3) contained in the component (B) is at least one selected from the following formulas (DB-1) to (DB-6).

The method according to claim 1,
Wherein the tetracarboxylic acid dianhydride as the component (B) is represented by the following formula (4) and X ₁ is at least one selected from the following structures.

The method according to claim 1,
The tetracarboxylic acid dianhydride of component (B) is at least one selected from 1,2,3,4-butanetetracarboxylic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. Type tetracarboxylic acid dianhydride, and the content of the tetracarboxylic acid dianhydride is 50 to 100 mol% based on the total tetracarboxylic acid dianhydride of the component (B). The method according to claim 1,
Wherein the tetracarboxylic acid dianhydride of component (B) is 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. The method according to claim 1,
Containing diamine represented by the following formula (5), in addition to the diamine represented by the formula (3), in the diamine compound of the component (B).

(In the formula (5), B ₃ is the same as B ₁ , B ₄ is a single bond, or an alkylene group having 1 to 4 carbon atoms, and m is an integer of 1 to 4) 13. The method of claim 12,
Wherein the diamine of the component (B) contains the diamine represented by the formula (3) and the diamine represented by the formula (5), and the total amount thereof is 40 to 100 mol% with respect to the total diamine of the component (B). 13. The method of claim 12,
A liquid crystal aligning agent wherein the diamine represented by the formula (5) is at least one selected from 3,5-diaminobenzoic acid and 2,5-diaminobenzoic acid. A liquid crystal alignment film characterized by being obtained by applying the liquid crystal alignment agent according to any one of claims 1 to 14 and firing the liquid crystal alignment film as the liquid crystal alignment film. Wherein the liquid crystal alignment layer is obtained by coating and firing the liquid crystal aligning agent according to any one of claims 1 to 14 and further irradiating polarized radiation as the liquid crystal alignment layer. An IPS driving type or FFS driving type liquid crystal display device comprising the liquid crystal alignment film according to claim 15. An IPS driving type or FFS driving type liquid crystal display device comprising the liquid crystal alignment film according to claim 16.