KR102672865B1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display device - Google Patents

Abstract

(식 중의 기호의 정의는 명세서에 나타내는 바와 같다.) Provided are polyamic acid esters that can maintain various properties at a high level even when blended with various polyamic acids, and polyamic acid ester/polyamic acid blend liquid crystal aligning agents using the same. A liquid crystal aligning agent containing polyamic acid ester (A) which has a repeating unit represented by Formula (1) and a repeating unit represented by Formula (2), and a polyamic acid (B).

(The definitions of symbols in the formula are as shown in the specification.)

Description

Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display device

This invention relates to a liquid crystal aligning agent containing polyamic acid ester, and a liquid crystal aligning film and a liquid crystal display element obtained from the liquid crystal aligning agent.

Liquid crystal display elements are currently widely used as display elements in digital cameras, notebook personal computers, and mobile portable terminals. Liquid crystal display elements are generally constructed from structural members such as liquid crystals, liquid crystal alignment films, electrodes, and substrates, and various drive methods are adopted depending on their uses. For example, in order to realize a wide viewing angle of a liquid crystal display device, an IPS (In Plane Switching) driving method using a transverse electric field or an improved version thereof, an FFS (Fringe-Field Switching) driving method, etc. have been adopted.

As a liquid crystal aligning film used in the above drive system, a liquid crystal aligning film using polyamic acid has been widely used. However, in order to satisfy the demand for further improvement in liquid crystal orientation, a liquid crystal aligning agent using polyamic acid ester is used.

Liquid crystal aligning agents using polyamic acid ester (hereinafter also referred to as PAE) are often used in a blended form with polyamic acid (hereinafter also referred to as PAA) in order to satisfy various properties required for liquid crystal display elements ( Hereinafter, such a liquid crystal aligning agent is also called a PAE/PAA blend liquid crystal aligning agent).

However, from the behavior of PAE, PAA, and solvent when a PAE/PAA blend liquid crystal aligning agent is applied, cases often occur in which the resulting liquid crystal alignment film cannot satisfy various properties required for a liquid crystal display element. In order to solve this problem, a liquid crystal aligning agent that blends PAA and PAE of a specific structure has been reported (Patent Document 1).

International Gazette WO2014-157143 Pamphlet

However, in recent years, with the high definition of liquid crystal display elements, it has been demanded that liquid crystal aligning agents also have various characteristics compatible at a high level. Among them, the fact that the material that can be used for PAA blended with PAE is limited to a specific structure makes it difficult to provide various characteristics to polyamic acid and, by extension, to the PAE/PAA blend liquid crystal aligning agent using it.

Therefore, the subject of this invention is to develop PAE which can make various characteristics compatible at a high level even if it blends with any PAA, and to develop a PAE/PAA blend type liquid crystal aligning agent using such PAE.

As a result of repeated studies, the present inventors have found a PAE/PAA blend liquid crystal that provides a liquid crystal alignment film having excellent liquid crystal orientation and electrical properties, regardless of the structure of the blended PAA, by PAE using a diamine of a specific structure as a raw material. An orientation agent was discovered, and the present invention was completed.

That is, the present invention is as follows.

1. A liquid crystal aligning agent characterized by containing a polyamic acid ester (A) having a repeating unit represented by the following formula (1) and a repeating unit represented by the formula (2), and a polyamic acid (B).

[Formula 1]

(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms. R ² to R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Y ¹ is represented by the following formula (Y ^1-2 ) Y ² is a divalent organic group represented by at least one divalent organic group selected from the group consisting of (Y ² -1) and (Y ² -2).

[Formula 2]

(In the formula, A ¹ and A ⁵ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms. A ² and A ⁴ are each independently an alkylene group having 1 to 5 carbon atoms. A ³ is an alkylene group having 1 to 6 carbon atoms, or B ¹ and B ² are each independently a single bond, -O-, -NH-, -NMe-, -C(=O)-, -. C(=O)O-, -C(=O)NH-, -C(=O)NMe-, -OC(=O)-, -NHC(=O)-, or -N(Me)C( =O)-. D ₁ is a tert-butoxycarbonyl group or 9-fluorenylmethoxycarbonyl group. a is 0 or 1, and n is an integer of 2 to 6.

The PAE/PAA blend liquid crystal aligning agent of the present invention is capable of expressing high liquid crystal orientation in the resulting liquid crystal aligning film, regardless of the structure of the PAA to be blended. Therefore, it becomes possible to select various PAAs, and it becomes possible to obtain a liquid crystal aligning agent that can satisfy various characteristics required for a liquid crystal display element at a high level.

＜Polyamic acid ester (A)＞

The polyamic acid ester used for the liquid crystal aligning agent of this invention contains a repeating unit of said formula (1) and a repeating unit of formula (2). The definitions of the symbols in equations (1) and (2) are as described above.

In addition, the alkyl group having 1 to 6 carbon atoms in formulas (1) and (2) may be linear or branched, and preferably has 1 to 4 carbon atoms. Preferred specific examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, and hexyl group.

In formula (1) and formula (2), from the viewpoint of liquid crystal orientation, R ² to R ⁵ is hydrogen, ^and R ³ and R ^{5 are} an alkyl group having 1 to 6 carbon atoms, especially a methyl group or It is preferable that it is an ethyl group, or that R ² and R ⁴ are an alkyl group having 1 to 6 carbon atoms, especially a methyl group or an ethyl group, and R ³ and R ⁵ are hydrogen.

Y ¹ in formula (1) is a divalent organic group represented by the following formula (Y ¹ -2), and the divalent organic group is derived from a diamine compound represented by the formula: H ₂ NY ¹ -NH ₂ .

[Formula 3]

The definitions of A ¹ , A ⁵ , A ² and A ⁴ in (Y ¹ -2) are the same as above, but in particular, from the point of reactivity with the functional group in the sealing agent, A ¹ and A ⁵ are: A single bond or methylene group is preferred. Moreover, A ² and A ⁴ are preferably methylene groups or ethylene groups.

A ³ is preferably a methylene group or an ethylene group from the viewpoint of reactivity with the functional group in the sealing agent. B ¹ and B ² are preferably a single bond or -O- from the viewpoint of liquid crystal orientation. D ₁ is preferably a tert-butoxycarbonyl group from the viewpoint of deprotection temperature. a is preferably 0 to 3.

Preferred specific examples of formula (Y ¹ -2) include the following formulas (1-1) to (1-21).

[Formula 4]

[Formula 5]

[Formula 6]

In formulas (1-1) to (1-21), Me represents a methyl group and D ₂ represents a tert-butoxycarbonyl group.

The content ratio of the repeating unit represented by formula (1) in the polyamic acid ester (A) is preferably 5 to 60 mol%, and more preferably 10 to 20 mol%, based on all repeating units.

Y ² in the repeating unit represented by formula (2) is a divalent organic group represented by at least one selected from the following formulas (Y ² -1) and (Y ² -2). The divalent organic group is derived from a diamine compound represented by the formula: H ₂ NY ² -NH ₂ .

[Formula 7]

In the formulas (Y ² -1) and (Y ² -2), n is particularly preferably an integer of 2 to 5, and more preferably an integer of 2.

The content ratio of the repeating unit represented by formula (2) in the polyamic acid ester (A) is preferably 10 to 70 mol% and more preferably 20 to 40 mol% with respect to all repeating units.

The polyamic acid ester used for the liquid crystal aligning agent of this invention has a repeating unit of the following formula (3) other than the repeating units of the said formula (1) and formula (2), to the degree which can exhibit the effect of this invention. It doesn’t matter if you have it.

[Formula 8]

In formula (3), R ¹ to R ⁵ have the same meaning as in formula (1) and formula (2). Moreover, Y ³ is a divalent organic group derived from a diamine compound represented by the formula: H ₂ NY ³ -NH ₂ , and its structure is appropriately selected from divalent organic groups other than Y ¹ and Y ² . Specific examples of Y ³ are given below.

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

As Y ³ , the structure represented by (Y-7) above is preferable from the viewpoint of liquid crystal orientation.

When the polyamic acid ester (A) contains the repeating unit represented by formula (3), the content ratio is preferably 10 to 50 mol%, more preferably 30 to 50 mol%, relative to all repeating units. .

＜Polyamic acid (B)＞

The polyamic acid used for the liquid crystal aligning agent of this invention is obtained by making a tetracarboxylic dianhydride component and a diamine component (polycondensation) react, and its structure is not specifically limited.

＜Tetracarboxylic dianhydride component＞

The tetracarboxylic dianhydride component, which is a raw material of the polyamic acid used in the present invention, is preferably represented by the following formula.

[Formula 23]

Specific examples of X include the following formulas (X-1) to (X-43). From the viewpoint of availability, (X-1) to (X-14) are more preferable, (X-1) (where R ₇ to R ₁₀ are all hydrogen atoms), (X-2), (X-3 ), (X-5), (X-6), (X-7), (X-8), (X-10), (X-11), or (X-14) are particularly preferred.

[Formula 24]

[Formula 25]

[Formula 26]

[Formula 27]

＜Diamine ingredient＞

Specific examples of diamine, which is the raw material of the polyamic acid used in the present invention, are H ₂ NY ¹ -NH ₂ , H ₂ NY ² -NH ₂ , or NH ₂ -Y, which are the raw materials of the polyamic acid ester (A) described above. ³ -NH ₂ (The definitions of Y ¹ , Y ² and Y ³ are the same as above).

<Production method of polyamic acid ester (A)>

<Method for producing polyamic acid ester>

The polyamic acid ester represented by the above formula (1) is tetracarboxylic dianhydride or any of its derivatives represented by the following formula (1a) or formula (1a'), H ₂ NY ¹ -NH ₂ , H ₂ NY ² -NH ₂ , or NH ₂ -Y ³ -NH ₂ (Y ¹ , Y ² and Y ³ are defined as above.) Formula: H ₂ NY ¹ -NH ₂ , H ₂ NY ² -NH ₂ , or NH ₂ -Y ³ -NH ₂ (the definitions of Y ¹ , Y ² and Y ³ are as described above).

[Formula 28]

In formula (1a) and formula (1a'), R ¹ to R ⁵ have the same meaning as above, and R is a hydroxyl group or a chlorine atom.

The polyamic acid ester represented by the formula (1) can be synthesized using the monomer, for example, by the methods (i) to (iii) shown below.

(i) Production method from polyamic acid

Polyamic acid ester can be manufactured by esterifying polyamic acid obtained from tetracarboxylic dianhydride represented by formula (1a) and a diamine compound represented by formula: H ₂ NY ¹ -NH ₂ .

Specifically, it is produced by reacting polyamic acid and an esterifying agent 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 4 hours. can do.

The esterifying agent is preferably one that can be easily removed by purification, and includes N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, and N,N-dimethylformamide dipropyl acetal. , N,N-dimethylformamide dineopentylbutyl acetal, N,N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltri Azene, 1-propyl-3-p-tolyltriazene, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, etc. . The amount of the esterifying agent used is preferably 2 to 6 molar equivalents per 1 mole of repeating units of the polyamic acid.

From the viewpoint of polymer solubility, the organic solvent is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, and γ-butyrolactone, and these can be used singly or in a mixture of two or more. It's okay too. The concentration of the polymer in the reaction system is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, because precipitation of the polymer does not occur easily and a high molecular weight body is easy to obtain.

(ii) Production method from tetracarboxylic acid dialkyl ester dichloride and diamine compound

Polyamic acid ester can be manufactured by polycondensing a tetracarboxylic acid dialkyl ester dichloride (when R is a chlorine atom) represented by formula (1a') and a diamine compound represented by formula (1b).

Specifically, tetracarboxylic acid dialkyl ester dichloride and a diamine compound are reacted in the presence of a base and an organic solvent at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 hours. It can be prepared by reacting for 1 to 4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine, etc. can be used, but pyridine is preferred so that the reaction proceeds gently. The amount of base added is preferably 2 to 4 times the mole of the tetracarboxylic acid dialkyl ester dichloride from the viewpoint of being an amount that is easy to remove and making it easy to obtain a high molecular weight product.

From the viewpoint of solubility of monomers and polymers, N-methyl-2-pyrrolidone and γ-butyrolactone are preferable as the organic solvent, and these may be used singly or in combination of two or more. The concentration of the polymer in the reaction system is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoints that precipitation of the polymer does not occur easily and that a high molecular weight polymer is easy to obtain. In addition, in order to prevent hydrolysis of tetracarboxylic acid dialkyl ester dichloride, the solvent used in the production of polyamic acid ester is preferably dehydrated as much as possible, and the incorporation of outside air is prevented in a nitrogen atmosphere. It is desirable to do so.

(iii) Production method from tetracarboxylic acid dialkyl ester and diamine compound

Polyamic acid ester can be manufactured by polycondensing a tetracarboxylic acid dialkyl ester (when R is a hydroxyl group) represented by formula (1a') and a diamine compound represented by the formula: H ₂ NY ¹ -NH ₂ .

Specifically, the tetracarboxylic acid dialkyl ester and the diamine compound are reacted in the presence of a condensing agent, a base, and an organic solvent at 0°C to 150°C, preferably 0°C to 100°C, for 30 minutes to 24 hours. It can be produced by reacting for 3 to 15 hours.

The condensing agent includes triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldiimidazole, and dimethoxy-1. ,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluroniumtetrafluoroborate, O-(benzotriazole- 1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzooxazolyl)phosphonate diphenyl, etc. You can. The amount of condensing agent used is preferably 2 to 3 times the mole of the tetracarboxylic acid dialkyl ester.

As the base, tertiary amines such as pyridine and triethylamine can be used. The amount of base added is preferably 2 to 4 times the mole of the diamine component from the viewpoint of being an amount that is easy to remove and making it easy to obtain a high molecular weight body.

Examples of the organic solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, and N,N-dimethyl from the viewpoint of solubility in tetracarboxylic acid dialkyl esters and diamines. Acetamide, N-methylcaprolactam, dimethylsulfoxide, dimethylsulfone and hexamethylsulfoxide are preferred. These may be used one type or two or more types.

Additionally, in this production method, the reaction proceeds efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The amount of Lewis acid added is preferably 0 to 1.0 times the mole of the diamine component.

Among the production methods of the above three types of polyamic acid esters, the production method (i) or (ii) above is particularly preferable because a high molecular weight polyamic acid ester is obtained.

The solution of polyamic acid ester obtained as described above can be injected into a poor solvent while stirring well to precipitate the polymer. Precipitation can be performed several times, washed with a poor solvent, and dried at room temperature or by heating to obtain a purified polyamic acid ester powder. The poor solvent is not particularly limited, but includes water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene, etc.

<Method for producing end-modified polyamic acid ester>

The terminal-modified polyamic acid ester has the following formula (1c') with respect to the polyamic acid ester having an amino group at the terminal obtained as described above:

[Formula 29]

(In the formula, A ⁵ and R ⁸ have the same meaning as above)

It is obtained by reacting the chlorocarbonyl compound represented by .

As for the chlorocarbonyl compound, the smaller the number of carbon atoms in the structure, the smaller the interaction between terminals, which can suppress aggregation of polyamic acid ester. Therefore, chlorocarbonyl compounds include acrylic acid chloride, methacrylic acid chloride, crotonic acid chloride, 2-furoyl chloride, 2-thenoyl chloride, ethyl chloroformate, vinyl chloroformate, cyclopentyl chloroformate, and chlorothioformate S. -phenyl, or C-29 is more preferred. Acrylic acid chloride, methacrylic acid chloride, crotonic acid chloride, 2-furoyl chloride or 2-thenoyl chloride are more preferred.

The terminal-modified polyamic acid ester is, specifically, a method of dissolving a powder of a polyamic acid ester having an amino group at the terminal in an organic solvent and then adding a chlorocarbonyl compound in the presence of a base to react, or formula: H ₂ When a diamine compound represented by NY ¹ -NH ₂ and a tetracarboxylic acid dialkyl ester derivative represented by formula (1a') are reacted in an organic solvent to obtain a polyamic acid ester having an amino group at the terminal, the polyamic acid ester is isolated. Alternatively, a method of adding a chlorocarbonyl compound to the reaction system and reacting it with a polyamic acid ester having an amino group at the terminal present in the reaction system may be mentioned. Among them, the method of adding a chlorocarbonyl compound to the latter reaction system is more preferable because the polyamic acid ester can be purified once by reprecipitation and the manufacturing process can be shortened.

In order to obtain the terminal-modified polyamic acid ester of the present invention, it is necessary to produce a polyamic acid ester in which an amino group is present at the terminal of the main chain. Therefore, the molar ratio of the diamine compound represented by formula (1b) and the tetracarboxylic acid dialkyl ester derivative represented by formula (1a') is preferably 1:0.7 to 1:1, and is 1:0.8 to 1:1. It is more preferable to be

Methods for adding a chlorocarbonyl compound to the above reaction system include adding it simultaneously with the tetracarboxylic acid dialkyl ester derivative and reacting it with diamine, or reacting the tetracarboxylic acid dialkyl ester derivative with the diamine sufficiently, so that the terminal There is a method of adding a chlorocarbonyl compound after producing polyamic acid ester, which is an amino group. The latter method is more preferable because it is easy to control the molecular weight of the polymer.

In the case of obtaining a terminal-modified polyamic acid ester, the reaction between a polyamic acid ester having an amino group at the terminal and a chlorocarbonyl compound is carried out in the presence of a base and an organic solvent at -20 to 150°C, preferably 0 to 50°C. At °C, it is preferably carried out for 30 minutes to 24 hours, preferably 30 minutes to 4 hours.

The amount of the chlorocarbonyl compound added is preferably 0.5 to 60 mol%, more preferably 1 to 40 mol%, based on one repeating unit of the polyamic acid ester having an amino group at the terminal. If the amount added is large, the unreacted chlorocarbonyl compound remains and it is difficult to remove, so it is more preferable that it is 1 to 20 mol%.

As the base, pyridine, triethylamine, or dimethylaminopyridine can be preferably used, but pyridine is preferred because the reaction proceeds gently. If the amount of base added is too large, removal is difficult, and if it is too small, the molecular weight becomes small. Therefore, the amount of base added is preferably 2 to 4 times the mole of the chlorocarbonyl compound.

The organic solvent used in the production of terminal-modified polyamic acid ester is preferably N-methyl-2-pyrrolidone and γ-butyrolactone from the solubility of monomers and polymers, and these are used singly or in a mixture of two or more. You can use it. If the concentration during production is too high, polymer precipitation is likely to occur, and if it is too low, the molecular weight does not increase. Therefore, the concentration is preferably 1 to 30 mass%, and more preferably 5 to 20 mass%. In addition, in order to prevent hydrolysis of the chlorocarbonyl compound, it is desirable to dehydrate the organic solvent used in the production of the terminal-modified polyamic acid ester as much as possible and store it in a nitrogen atmosphere to prevent entry of external air. do.

<Method for producing polyamic acid (B)>

The polyamic acid (B) of the present invention can be obtained by reaction between a tetracarboxylic dianhydride component and a diamine component. Specifically, the tetracarboxylic dianhydride component and the diamine component are incubated at -20°C to 150°C, preferably 0°C to 50°C, in the presence of an organic solvent for 30 minutes to 24 hours, preferably 1. It can be prepared by reacting for ~12 hours.

From the viewpoint of the solubility of monomers and polymers, the organic solvent is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone, and one or two or more of these are used. You may mix and use them. The concentration of the polymer in the reaction system is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoints that precipitation of the polymer does not occur easily and that a high molecular weight body is easy to obtain.

The polyamic acid obtained as described above can be recovered by injecting the reaction solution into a poor solvent while stirring well to precipitate the polymer. In addition, a purified polyamic acid powder can be obtained by performing precipitation several times, washing with a poor solvent, and drying at room temperature or by heating. The poor solvent is not particularly limited, but includes water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene, etc.

＜Liquid crystal alignment agent＞

The liquid crystal aligning agent of this invention preferably has the form of a solution in which polyamic acid ester (A) and polyamic acid (B) were dissolved in an organic solvent. The molecular weight of polyamic acid ester (A) is the weight average molecular weight, and is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and even more preferably 10,000 to 100,000. Moreover, 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.

On the other hand, the weight average molecular weight of the polyamic acid (B) is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and still more preferably 10,000 to 100,000. Moreover, 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.

By making the molecular weight of the polyamic acid ester (A) smaller than the molecular weight of the polyamic acid (B), micro-irregularities due to phase separation can be further reduced. The difference between the average molecular weight of the polyamic acid ester (A) and the polyamic acid (B) is the weight average molecular weight, preferably 1,000 to 1,200,000, more preferably 3,000 to 80,000, and especially 5,000 to 60,000. desirable.

It is preferable that the mass ratio (polyamic acid ester/polyamic acid) of polyamic acid ester (A) and polyamic acid (B) contained in the liquid crystal aligning agent of this invention is 1/9 - 9/1. This ratio is more preferably 2/8 to 8/2, and particularly preferably 3/7 to 7/3. By setting this ratio within this range, it is possible to provide a liquid crystal aligning agent with good liquid crystal orientation and electrical properties.

The liquid crystal aligning agent of this invention preferably has the form of a solution in which polyamic acid ester (A) and polyamic acid (B) were dissolved in an organic solvent. There is no particular limitation on the production method, but for example, a method of mixing the powder of both polyamic acid ester and polyamic acid and dissolving it in an organic solvent, a method of mixing the powder of polyamic acid ester and a solution of polyamic acid, polyamic acid There is a method of mixing a solution of polyamic acid ester and a polyamic acid powder, and a method of mixing a solution of polyamic acid ester and a solution of polyamic acid. Since a uniform polyamic acid ester-polyamic acid mixed solution can be obtained even when the good solvents for dissolving the polyamic acid ester and the polyamic acid are different, the method of mixing the polyamic acid ester solution and the polyamic acid solution is more preferable.

In addition, when producing polyamic acid ester or polyamic acid in an organic solvent, the solution of polyamic acid ester and the solution of polyamic acid may be the reaction solutions obtained respectively, or may be diluted with an appropriate solvent. It's okay. Additionally, when polyamic acid ester or polyamic acid is obtained as a powder, it may be dissolved in an organic solvent to form a solution. At this time, the total polymer concentration in the organic solvent is preferably 10 to 30 mass%, and particularly preferably 10 to 15 mass%. Additionally, you may heat the polyamic acid ester and/or polyamic acid powder when dissolving it. The heating temperature is preferably 20 to 150°C, and particularly preferably 20 to 80°C.

The total content (solid content concentration) of polyamic acid ester (A) and polyamic acid (B) in the liquid crystal aligning agent of this invention can be appropriately changed according to the setting of the thickness of the liquid crystal aligning film to be formed. Among them, in order to form a uniform and defect-free coating film, it is preferably 0.5% by mass or more relative to the organic solvent, and in terms of storage stability of the solution, it is preferably 15% by mass or less. 0.5 to 10 mass% is more preferable, and 1 to 10 mass% is particularly preferable.

The liquid crystal aligning agent of this invention may contain other polymers which have liquid crystal orientation in addition to polyamic acid ester (A) and polyamic acid (B). These other polymers include polyamic acid esters other than polyamic acid ester (A), soluble polyimides, and/or polyamic acids other than polyamic acid (B).

The organic solvent which the liquid crystal aligning agent of this invention may contain is not specifically limited as long as the polymer components of polyamic acid ester (A) and polyamic acid (B) are dissolved uniformly. Specific examples include N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone. , N-methylcaprolactam, 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethylsulfoxide, dimethylsulfone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, 3 -Methoxy-N,N-dimethylpropanamide, etc. can be mentioned. These may be used singly or in mixture of two or more types. Moreover, from the viewpoint of compatibility of PAE and PAA contained in the liquid crystal aligning agent of this invention, if the content rate of N-methyl-2-pyrrolidone is 30-50 mass % with respect to the total weight of the liquid crystal aligning agent. desirable. Moreover, even if it is a solvent that cannot uniformly dissolve the polymer component alone, it may be mixed with the above-mentioned organic solvent as long as it is within the range in which the polymer does not precipitate.

In addition to the organic solvent for dissolving the polymer component, the liquid crystal aligning agent of the present invention may contain a solvent for improving coating film uniformity when applying the liquid crystal aligning agent to a substrate. These solvents generally have a lower surface tension than the organic solvents described above. Specific examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-Butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether- 2-Acetate, butyl cellosolve acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate. Ester, etc. can be mentioned. Two or more types of these solvents can be used in combination.

The liquid crystal aligning agent of this invention may contain various additives, such as a silane coupling agent and a crosslinking agent. When adding a silane coupling agent or a crosslinking agent, in order to prevent polymer precipitation, when adding a poor solvent to a liquid crystal aligning agent, it is preferable to add it before that. In addition, in order to efficiently advance imidization of polyamic acid ester (A) and polyamic acid (B) when baking the coating film, an imidization accelerator may be added.

When adding a silane coupling agent to the liquid crystal aligning agent of the present invention, before mixing the polyamic acid ester solution and the polyamic acid solution, it is added to the polyamic acid ester solution, the polyamic acid solution, or both the polyamic acid ester solution and the polyamic acid solution. It can be added. Additionally, the silane coupling agent can be added to the polyamic acid ester-polyamic acid mixed solution. Since the silane coupling agent is added for the purpose of improving the adhesion between the polymer and the substrate, the method of adding the silane coupling agent is to add it to a polyamic acid solution that can be distributed inside the film and at the substrate interface, and to mix the polymer and the silane coupling agent. A more preferable method is to react sufficiently and then mix with the polyamic acid ester solution. If the amount of the silane coupling agent added is too large, the unreacted agent may have a negative effect on the liquid crystal orientation, and if it is too small, the effect on adhesion is not observed. Therefore, the amount is preferably 0.01 to 5.0% by mass based on the solid content of the polymer. , 0.1 to 1.0 mass% is more preferable.

Specific examples of the silane coupling agent are given below, but the silane coupling agent that can be used in the liquid crystal aligning agent of the present invention is not limited to this. 3-Aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3- Amine-based silane coupling agents such as phenylaminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, and 3-aminopropyldiethoxymethylsilane; Vinyltrime Toxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, vinylmethyldimethoxysilane, vinyltriacetoxysilane, vinyltriisopropoxysilane, allyltrimethoxysilane, p-styryl Vinyl silane coupling agents such as trimethoxysilane; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxy Epoxy-based silane coupling agents such as propylmethyldimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; 3-methacryloxypropylmethyldimethoxysilane and 3-methacryloxypropyltrimethoxy Methacrylic silane coupling agents such as silane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; Acrylic silane coupling agents such as 3-acryloxypropyltrimethoxysilane; 3- Uride-based silane coupling agents such as ureide propyltriethoxysilane; sulfides such as bis(3-(triethoxysilyl)propyl)disulfide and bis(3-(triethoxysilyl)propyl)tetrasulfide Silane coupling agents; Mercapto-based silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-octanoylthio-1-propyltriethoxysilane; 3-isocyanate Isocyanate-based silane coupling agents such as propyltriethoxysilane and 3-isocyanatepropyltrimethoxysilane; aldehyde-based silane coupling agents such as triethoxysilylbutyraldehyde; triethoxysilylpropylmethylcarbamate, (3-tri Carbamate-based silane coupling agents such as ethoxysilylpropyl)-t-butylcarbamate.

Specific examples of imidization accelerators for polyamic acid ester (A) and polyamic acid (B) are given below, but are not limited to these.

[Formula 30]

D in the above formulas (I-1) to (I-17) each independently represents a t-butoxycarbonyl group, a 9-fluorenylmethoxycarbonyl group, or a carbobenzoxy group. In addition, in (I-14) to (I-17), a plurality of Ds exist in one formula, but they may be the same or different from each other.

The content of the imidization accelerator is not particularly limited as long as it is within a range where the effect of promoting thermal imidization of polyamic acid ester (A) and polyamic acid (B) is obtained. The lower limit is preferably 0.01 mol or more, more preferably 0.05 mol or more, and even more preferably 0.1 mol or more, based on 1 mole of amic acid or its ester moiety contained in the polyamic acid ester. In addition, if the imidization accelerator itself remaining in the film after baking shows the upper limit from the viewpoint of minimizing the adverse influence on the various characteristics of the liquid crystal alignment film, the polyamic acid ester and polyamic acid (B) of the present invention are included. Preferably the imidization accelerator is 2 mol or less, more preferably 1 mol or less, and even more preferably 0.5 mol or less per 1 mol of the mixed acid or its ester moiety.

When adding an imidization accelerator, it is preferable to add it after diluting with a good solvent and a poor solvent because imidization may progress by heating.

＜Liquid crystal alignment film＞

The liquid crystal aligning film of the present invention is a film in which the liquid crystal aligning agent is applied to a substrate, dried, baked, and then subjected to an orientation treatment.

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 highly transparent substrate, and a glass substrate, a silicon nitride substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, etc. can be used. From the viewpoint of process simplification, it is preferable to use a substrate on which ITO electrodes for driving liquid crystal are formed. In addition, in a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is used as a substrate on only one side, and a light-reflecting material 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 spin coating, printing, and inkjet methods. For the drying and baking steps after applying the liquid crystal aligning agent, arbitrary temperature and time can be selected. Usually, in order to sufficiently remove the organic solvent contained, it is dried at 50 to 120°C for 1 to 10 minutes, and then baked at 150 to 300°C for 5 to 120 minutes. The thickness of the coating film after baking is not particularly limited, but if it is too thin, the reliability of the liquid crystal display element may decrease, so it is 5 to 300 nm, preferably 10 to 200 nm.

Methods for aligning this coating film include a rubbing method and a photo-alignment treatment method. However, the liquid crystal aligning agent of the present invention is particularly useful when used in a photo-alignment treatment method.

As a specific example of the photo-alignment treatment method, the surface of the coating film is irradiated with radiation polarized in a certain direction, and in some cases, heat treatment is further performed at a temperature of 150 to 250 ° C. to provide liquid crystal orientation ability. can be mentioned. As radiation, ultraviolet rays and visible rays having a wavelength of 100 to 800 nm can be used. Among these, ultraviolet rays with a wavelength of 100 to 400 nm are preferable, and those with a wavelength of 200 to 400 nm are particularly preferable. Moreover, in order to improve the liquid crystal orientation, you may irradiate radiation while heating a coating film board|substrate at 50-250 degreeC. The radiation dose is preferably in the range of 1 to 10,000 mJ/cm2, and particularly preferably in the range of 100 to 5,000 mJ/cm2. The manufactured liquid crystal alignment film can stably orientate liquid crystal molecules in a certain direction.

＜Liquid crystal display device＞

The liquid crystal display element of the present invention is obtained by obtaining a substrate with a liquid crystal aligning film from the liquid crystal aligning agent, then producing a liquid crystal cell by a known method to obtain a liquid crystal display element.

An example of manufacturing a liquid crystal cell is as follows. First, prepare a pair of substrates on which a liquid crystal alignment film is formed. Next, a spacer is spread on the liquid crystal alignment film of one side of the board|substrate, the liquid crystal alignment film surface becomes inside, and after bonding the board|substrate of the other side together, the liquid crystal is injected under reduced pressure and sealed. Alternatively, after dropping the liquid crystal on the surface of the liquid crystal alignment film on which the spacer was spread, the substrates may be bonded together and sealed. The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.

Example

The present invention will be described in more detail below with reference to examples. However, the present invention is not to be construed as being limited to these examples.

The abbreviations of the compounds used hereafter and the measurement methods for each characteristic are as follows.

＜Monomer＞

1,3DMCBDE-Cl: Dimethyl1,3-bis(chlorocarbonyl)-1,3-dimethylcyclobutane-2,4-dicarboxylate

CBDA: 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride

BDA: 1,2,3,4-butanetetracarboxylic acid dianhydride

PMDA: Pyromellitic dianhydride

BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride

BAPU: 1,3-bis(4-aminophenethyl)urea

DADPA: 4,4'-diaminodiphenylamine

Me-DADPA: N,N-bis(aminophenyl)-methylamine

DBA: 3,5-diaminobenzoic acid

p-PDA: p-phenylenediamine

TDA: 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4,-tetrahydronaphthalene-1,2,-dicarboxylic acid anhydride

DDM: 4,4'-diaminodiphenylmethane

[Formula 31]

＜Solvent＞

NMP: N-methyl-2-pyrrolidone,

BCS: Butylcellosolve,

BCA: Butyl cellosolve acetate,

GBL: γ-butyrolactone

PB: propylene glycol monobutyl ether,

DME: 1,2-Dimethoxyethane

DIBC: Diisobutylcarbinol,

DAA: Diacetone alcohol

＜Viscosity＞

In the synthesis example, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) at a sample volume of 1.1 ml, condenser TE-1 (1°34', R24), and a temperature of 25°C. Measured.

＜Molecular weight＞

In the synthesis example, the molecular weight of the polymer was measured by GPC (room temperature gel permeation chromatography) equipment, and the number average molecular weight (hereinafter also referred to as Mn) and weight average molecular weight (hereinafter referred to as Mw) were calculated as polyethylene glycol and polyethylene oxide conversion values. Also called.) was calculated.

GPC device: manufactured by Shodex (GPC-101)

Column: manufactured by Shodex (series of KD803 and KD805), column temperature: 50°C

Eluent: N,N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr·H ₂ O) is 30 mmol/l, phosphoric acid/anhydrous crystal (o-phosphoric acid) is 30 mmol/l, tetrahydrofuran (THF) 10 ㎖/ℓ)

Flow rate: 1.0 mL/min

Standard sample for creating a calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (weight average molecular weight (Mw) approximately 900,000, 150,000, 100,000, 30,000), and polyethylene glycol manufactured by Polymer Laboratories (peak top molecular weight (Mp) approximately 12,000, 4,000, 1,000). To avoid overlapping peaks, two samples were measured separately: a sample mixed with 900,000, 100,000, 12,000, and 1,000, and a sample mixed with 150,000, 30,000, and 4,000.

＜Measurement of surface roughness＞

The coating film of the liquid crystal aligning agent obtained by spin coat application was dried on a hot plate at a temperature of 80°C for 5 minutes, and the film was imidized through baking for 10 minutes in a hot air circulation oven at a temperature of 230°C and has a film thickness of 100 nm. got it The fired film was irradiated with 254 nm ultraviolet rays in an amount described later through a polarizing plate, and a substrate with a liquid crystal alignment film was obtained. The film surface of this coating film was observed with an atomic force microscope (AFM), the center line average roughness (Ra) of the film surface was measured, and the flatness of the film surface was evaluated. Measuring device: L-trace probe microscope (manufactured by SII Technology)

(Synthesis Example 1)

In a 2 ℓ separable flask equipped with a stirring device and a nitrogen inlet tube, 10.00 g (92.4 mmol) of p-PDA, 13.60 g (55.5 mmol) of DA-B, and 12.60 g (37.0 mmol) of DA-C were added. mol), and 379.00 g of NMP, 1023.00 g of GBL, and 34.60 g (0.43 mol) of pyridine were added and dissolved. Next, 58.30 g (179.4 mmol) of 1,3DMCBDE-Cl was added while stirring this solution, and reacted under water cooling for 14 hours. After adding 2.40 g (26.6 mmol) of acryloyl chloride to the obtained polyamic acid solution and reacting for an additional 4 hours, this solution was poured into 8653 mL of isopropanol while stirring, and the precipitated white precipitate was collected by filtration. Subsequently, 21635 mL of isopropanol was used in five divided doses to wash and dry to obtain white polyamic acid ester resin powder (PWD-1). The molecular weight of this polyamic acid ester was Mn = 24,366 and Mw = 54,808.

The polyamic acid ester resin powder (PWD-1) obtained above was dissolved in GBL to obtain a polyamic acid ester solution (PAE-1) with a solid content concentration of 12% by mass.

(Synthesis Example 2)

In a 2 ℓ separable flask equipped with a stirring device and a nitrogen inlet tube, 10.00 g (92.4 mmol) of p-PDA, 11.30 g (46.24 mmol) of DA-B, and 5.26 g (15.41 mmol) of DA-C were added. mol), and 1230.9 g of a mixed solution adjusted so that the mass ratio of NMP and GBL was 25:75 and 28.38 g (358.79 mmol) of pyridine were added and dissolved. Next, 48.60 g (358.79 mmol) of 1,3DMCBDE-Cl was added while stirring this solution, and reacted under water cooling for 14 hours. 2.008 g (22.19 mmol) of acryloyl chloride was added to the obtained polyamic acid solution, and after reacting for an additional 4 hours, this solution was added to 5132 ml of isopropanol while stirring, and the precipitated white precipitate was collected by filtration. Subsequently, 1711 mL of isopropanol was used in five divided doses to wash and dry to obtain white polyamic acid ester resin powder (PWD-2). The molecular weight of this polyamic acid ester was Mn = 25,386 and Mw = 58,908.

The polyamic acid ester resin powder (PWD-2) obtained above was dissolved in GBL to obtain a polyamic acid ester solution (PAE-2) with a solid content concentration of 12% by mass.

(Synthesis Example 3)

Weigh 4.80 g (24.0 mmol) of DADPA and 1.20 g (6.00 mmol) of DDM in a 100 mL four-neck flask equipped with a stirring device and a nitrogen inlet tube, add 85.50 g of NMP, and add nitrogen. Stir and dissolve. While stirring this diamine solution, 1.40 g (6.90 mmol) of CBDA and 5.60 g (22.5 mmol) of DH-A were added, and NMP was added so that the solid content concentration was 12% by weight, and stirred at room temperature for 24 hours. A polyamic acid solution (PAA-1) was obtained. The viscosity of this polyamic acid solution at a temperature of 25°C was 1918 mPa·s. Additionally, the molecular weight of this polyamic acid was Mn = 13,384, Mw = 32,796.

Additionally, 13.00 g of a 3-glycidoxypropylmethyldiethoxysilane solution diluted to 0.3% by mass with a mixed solution with a NMP/GBL mass ratio of 2/8 was added to this solution to obtain a polyamic acid solution (PAA-1).

(Synthesis Example 4)

In a 100 mL four-neck flask equipped with a stirring device and a nitrogen inlet tube, 2.09 g (7.00 mmol) of BAPU and 5.55 g (27.99 mol) of DDM were weighed, 10.00 g of NMP and 10.00 g of GBL were added, It was stirred and dissolved while passing nitrogen. While stirring this diamine solution, 3.91 g (19.93 mmol) of CBDA and 2.77 g (13.98 mmol) of BDA were added so that the solid content concentration was 15% by weight and the mass ratio of NMP: GBL was 2:8. Both solvents were added as much as possible, and the mixture was stirred at room temperature for 24 hours to obtain a polyamic acid solution (PAA-2). The viscosity of this polyamic acid solution at a temperature of 25°C was 752 mPa·s. Additionally, the molecular weight of this polyamic acid was Mn = 12,385, Mw = 30,896.

(Synthesis Example 5)

In a 100 ㎖ four-neck flask equipped with a stirring device and a nitrogen inlet tube, 2.103 g (13.99 mmol) of Me-4APhA and 4.20 g (20.97 mmol) of DDE were weighed, 10.00 g of NMP, and 10.00 g of GBL. It was added, stirred and dissolved while sending nitrogen. While stirring this diamine solution, 2.40 g (12.24 mmol) of CBDA and 5.25 g (20.98 mmol) of DH-A were added so that the solid content concentration was 15% by weight and the mass ratio of NMP: GBL was 2: Both solvents were added to 8 and stirred at room temperature for 24 hours to obtain a polyamic acid solution (PAA-3). The viscosity of this polyamic acid solution at a temperature of 25°C was 652 mPa·s. Additionally, the molecular weight of this polyamic acid was Mn = 11,385, Mw = 29,896.

(Synthesis Example 6)

Weigh 2.103 g (6.99 mmol) of DBA and 4.90 g (24.47 mmol) of DDE in a 100 mL four-neck flask equipped with a stirring device and nitrogen inlet tube, add 10.00 g of NMP, and 10.00 g of GBL. , stirred and dissolved while sending nitrogen. While stirring this diamine solution, 1.23 g (6.27 mmol) of CBDA and 5.54 g (27.96 mmol) of BDA were added so that the solid content concentration was 15% by weight and the mass ratio of NMP: GBL was 2:8. Both solvents were added as much as possible, and the mixture was stirred at room temperature for 24 hours to obtain a polyamic acid solution (PAA-4). The viscosity of this polyamic acid solution at a temperature of 25°C was 682 mPa·s. Additionally, the molecular weight of this polyamic acid was Mn = 11,225, Mw = 30,196.

(Synthesis Example 7)

In a 100 mL four-neck flask equipped with a stirring device and a nitrogen inlet tube, 1.052 g (7.00 mmol) of Me-4APhA, 4.20 g (20.97 mmol) of DDE, and 1.395 g (7.00 mmol) of DADPA were weighed. Then, 10.00 g of NMP and 10.00 g of GBL were added, and the mixture was stirred and dissolved while passing nitrogen. While stirring this diamine solution, 1.24 g (6.32 mmol) of CBDA and 5.54 g (27.96 mmol) of BDA were added so that the solid content concentration was 15% by weight and the mass ratio of NMP: GBL was 2:8. Both solvents were added as much as possible, and the mixture was stirred at room temperature for 24 hours to obtain a polyamic acid solution (PAA-5). The viscosity of this polyamic acid solution at a temperature of 25°C was 672 mPa·s. Additionally, the molecular weight of this polyamic acid was Mn = 12,385, Mw = 30,226.

<Comparative synthesis example 1>

A 500 mL four-neck flask equipped with a stirring device was placed in a nitrogen atmosphere, and 4.58 g (42.4 mmol) of p-pD, 1.79 g (4.71 mmol) of DA-A, 84.70 g of NMP, and 254.00 g of GBL were added. , and 8.40 g (106 mmol) of pyridine as a base were added and stirred to dissolve. Next, 14.4 g (44.2 mmol) of 1,3DMCBDE-Cl was added while stirring this diamine solution, and it was made to react at 15 degreeC overnight. After stirring overnight, 1.23 g (13.6 mmol) of acryloyl chloride was added, and reaction was performed at 15°C for 4 hours. The obtained solution of polyamic acid ester was added while stirring to 1477.00 g of IPA, the precipitated white precipitate was collected by filtration, and then washed 5 times with 738 g of IPA and dried to obtain 17.30 g of white polyamic acid ester resin powder. got it The yield was 96.9%. Additionally, the molecular weight of this polyamic acid ester was Mn = 14,288, Mw = 29,956.

3.69 g of the obtained polyamic acid ester resin powder was placed in a 100 mL Erlenmeyer flask, 33.2 g of GBL was added, and the mixture was stirred and dissolved at room temperature for 24 hours to obtain a 10% concentration polyamic acid ester solution (PAE-3).

<Comparative synthesis example 2>

1.20 g (8.00 mmol) of DBA was weighed and placed in a 300 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, 7.30 g of NMP was added, and the flask was dissolved by stirring while sending nitrogen. Next, 6.80 g (32.0 mmol) of Me-DADPA and 18.30 g of GBL were added, and the mixture was stirred and dissolved while sending nitrogen. While stirring this diamine solution, 7.19 g (36.0 mmol) of BDA and 18.30 g of GBL were added, and it was diluted with GBL so that the solid content concentration was 25%, and stirred under water cooling for 2 hours. Next, 0.90 g (4.00 mmol) of PMDA was added, GBL was added so that the solid content concentration in the system was 18%, and the mixture was stirred under water cooling for 24 hours. The viscosity of the obtained polyamic acid solution at a temperature of 25.0°C was 780 mPa·s. Additionally, the molecular weights of this polyamic acid were Mn = 11700 and Mw = 24780.

Additionally, 16.0 g of 3-glycidoxypropylmethyldiethoxysilane solution diluted to 0.3% by mass with a mixed solution with a NMP/GBL mass ratio of 2/8 was added to this solution to obtain a polyamic acid solution (PAA-6). .

(Example 1)

In a 20 mL sample tube containing a stirrer, 1.80 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.80 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were taken, 4.90 g of NMP, 6.70 g of GBL and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-1) was obtained. As a result of storing liquid crystal aligning agent A-1 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 2)

In a 20 mL sample tube equipped with a stirrer, 1.80 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.80 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and NMP was added at 3.10 g. g, 8.50 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-2) was obtained. As a result of storing liquid crystal aligning agent A-2 at -20 degreeC for 1 week, precipitation of solid matter was not observed and it was a uniform solution.

(Example 3)

In a 20 mL sample tube equipped with a stirrer, 1.80 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.80 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and 1.30 g of NMP was added. g, 10.30 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-3) was obtained. As a result of storing liquid crystal aligning agent A-3 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 4)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.40 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and 5.30 g of NMP was added. g, 6.20 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-4) was obtained. As a result of storing liquid crystal aligning agent A-4 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 5)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.40 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and 3.50 g of NMP was added. g, 8.00 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-5) was obtained. As a result of storing liquid crystal aligning agent A-5 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 6)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.40 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and 1.70 g of NMP was added. g, 9.80 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-6) was obtained. As a result of storing liquid crystal aligning agent A-6 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 7)

In a 20 mL sample tube equipped with a stirrer, 3.00 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.00 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and NMP was added at 5.60 g. g, 6.60 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-7) was obtained. As a result of storing liquid crystal aligning agent A-7 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 8)

In a 20 mL sample tube equipped with a stirrer, 3.00 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.00 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and NMP was added at 3.80 g. g, 7.40 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-8) was obtained. As a result of storing liquid crystal aligning agent A-8 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 9)

In a 20 mL sample tube equipped with a stirrer, 3.00 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.00 g of the polyamic acid solution (PAA-1) obtained in Synthesis Example 3 were weighed and placed, and NMP was added at 3.80 g. g, 7.40 g of GBL, and 1.80 g of BCA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-9) was obtained. As a result of storing liquid crystal aligning agent A-9 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 10)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.40 g of the polyamic acid solution (PAA-3) obtained in Synthesis Example 5 were weighed and placed, and 1.70 g of NMP was added. g, 9.80 g of GBL, and 1.80 g of PB were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-10) was obtained. As a result of storing liquid crystal aligning agent A-6 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 11)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.40 g of the polyamic acid solution (PAA-4) obtained in Synthesis Example 6 were weighed and placed, and 1.70 g of NMP was added. g, 9.80 g of GBL, and 1.80 g of DME were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-11) was obtained. As a result of storing liquid crystal aligning agent A-6 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 12)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 1 and 2.40 g of the polyamic acid solution (PAA-5) obtained in Synthesis Example 7 were weighed and placed, and 1.70 g of NMP was added. g, 9.80 g of GBL, and 1.80 g of DPM were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-12) was obtained. As a result of storing liquid crystal aligning agent A-6 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 13)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-2) obtained in Synthesis Example 2 and 2.40 g of the polyamic acid solution (PAA-3) obtained in Synthesis Example 5 were weighed and placed, and 1.70 g of NMP was added. g, 9.80 g of GBL, and 1.80 g of DAA were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-13) was obtained. As a result of storing liquid crystal aligning agent A-6 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Example 14)

In a 20 mL sample tube equipped with a stirrer, 2.40 g of the polyamic acid ester solution (PAE-1) obtained in Synthesis Example 2 and 2.40 g of the polyamic acid solution (PAA-4) obtained in Synthesis Example 6 were weighed and placed, and 1.70 g of NMP was added. g, 9.80 g of GBL, and 1.80 g of DIBC were added, stirred with a magnetic stirrer for 30 minutes, and a liquid crystal aligning agent (A-14) was obtained. As a result of storing liquid crystal aligning agent A-6 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Comparative Example 1)

In a 20 mL sample tube equipped with a stirrer, 8.0 g of the polyamic acid ester solution (PAE-3) obtained in Comparative Synthesis Example 1 and 7.50 g of the polyamic acid solution (PAA-6) obtained in Comparative Synthesis Example 2 were weighed and placed into NMP. 3.70 g, 25.80 g of GBL, and 5.00 g of BCA were added, stirred for 30 minutes with a magnetic stirrer, and a liquid crystal aligning agent (B-1) was obtained. As a result of storing liquid crystal aligning agent B-1 at -20 degreeC for 1 week, precipitation of solid matter was not seen and it was a uniform solution.

(Comparative Example 2)

In a 20 mL sample tube equipped with a stirrer, 8.00 g of the polyamic acid ester solution (PAE-3) obtained in Comparative Synthesis Example 1 and 7.50 g of the polyamic acid solution (PAA-6) obtained in Comparative Synthesis Example 2 were weighed and placed into NMP. 13.7 g, 15.8 g of GBL, and 5.0 g of BCA were added, stirred for 30 minutes with a magnetic stirrer, and a liquid crystal aligning agent (B-2) was obtained. When liquid crystal aligning agent A-1 was stored at -20°C for 1 week, precipitation of solid matter was observed.

(Example 15)

After filtering the liquid crystal aligning agent (A-1) obtained in Example 1 with a 1.0-μm filter, it was spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-1) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 16)

After filtering the liquid crystal aligning agent (A-2) obtained in Example 2 with a 1.0-μm filter, it was spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-2) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 17)

After filtering the liquid crystal aligning agent (A-3) obtained in Example 3 with a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-3) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 18)

After filtering the liquid crystal aligning agent (A-4) obtained in Example 4 with a 1.0-μm filter, it was spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-4) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 19)

After filtering the liquid crystal aligning agent (A-5) obtained in Example 5 with a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-5) was obtained. For this film liquid crystal orientation, the average surface roughness (Ra) was measured and shown in Table 1.

(Example 20)

After filtering the liquid crystal aligning agent (A-6) obtained in Example 6 through a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-6) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 21)

After filtering the liquid crystal aligning agent (A-7) obtained in Example 7 with a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-7) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 22)

After filtering the liquid crystal aligning agent (A-8) obtained in Example 8 with a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-8) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 23)

After filtering the liquid crystal aligning agent (A-9) obtained in Example 9 with a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. The fired film was irradiated with 250 mJ/cm ² ultraviolet rays of 254 nm through a polarizing plate, and a substrate with a liquid crystal alignment film (C-9) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Comparative Example 3)

After filtering the liquid crystal aligning agent (B-1) obtained in Comparative Example 1 with a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 60°C for 5 minutes, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. 500 mJ/cm ² of 254 nm ultraviolet rays were irradiated to the baked film through a polarizing plate, and a substrate with a liquid crystal alignment film (D-1) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Comparative Example 4)

After filtering the liquid crystal aligning agent (B-2) obtained in Comparative Example 2 with a 1.0 μm filter, it is spin-coated on a glass substrate with a transparent electrode, dried for 5 minutes on a hot plate at a temperature of 60°C, and dried at a temperature of 230°C. After baking for 10 minutes in a hot air circulation oven at ℃, an imidized film with a film thickness of 100 nm was obtained. 500 mJ/cm ² of 254 nm ultraviolet rays were irradiated to the fired film through a polarizing plate, and a substrate with a liquid crystal alignment film (D-2) was obtained. About this liquid crystal aligning film, the average surface roughness (Ra) is measured and shown in Table 1.

(Example 24)

The number of photoelectrons on the film surface of the substrate (C-1) obtained in Example 15 was measured using an ionization potential measuring device AC-2 (Riken instrument). When the measurement film was made of two or more types of materials, the number of individual photoelectrons in each material was measured, and the layer separation ratio when mixed was calculated from the photoelectron ratio. For example, if the number of photoelectrons in the single film of material A is It can be expressed. The results calculated based on this equation are shown in Table 1.

C = (Y - Z)/(Y - X) * 100

(Examples 25 to 32, Comparative Examples 5 and 6)

The same operation as in Example 24 was performed on the substrates (C-2) to (C-9), (D-1), and (D-2) obtained after Example 15, and the number of photoelectrons on the film surface was measured. and is shown in Table 1.

＜Manufacturing method of orientation evaluation cell＞

· Manufacturing method of evaluation cell

First, a substrate with electrodes attached was prepared. The substrate is a glass substrate with a size of 30 mm x 50 mm and a thickness of 0.7 mm. On the substrate, an ITO electrode with a beta phase pattern, which constitutes a counter electrode, is formed as the first layer. On the counter electrode of the first layer, a SiN (silicon nitride) film formed as the second layer by the CVD method is formed. The SiN film of the second layer has a film thickness of 500 nm and functions as an interlayer insulating film. On the SiN film of the second layer, a comb-shaped pixel electrode formed by patterning an ITO film as the third layer is disposed, forming two pixels, a first pixel and a second pixel. The size of each pixel is 10 mm vertically and approximately 5 mm horizontally. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the action of the SiN film of the second layer.

The third layer pixel electrode has a comb-shaped shape formed by arranging a plurality of "く" shaped electrode elements with a curved central portion. The width of each electrode element in the short direction is 3 μm, and the spacing between electrode elements is 6 μm. Since the pixel electrode forming each pixel is composed of multiple arrays of く-shaped electrode elements with a curved central portion, the shape of each pixel is not rectangular, but is curved in the central portion like the electrode element, in bold letters. It has a shape resembling the character く. Each pixel is divided into upper and lower parts with the central curved part as a boundary, and has a first area above the curved part and a second area below the curved part.

When comparing the first region and the second region of each pixel, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, based on the orientation direction of the liquid crystal alignment film, which will be described later, the electrode elements of the pixel electrode are formed to form an angle of +10° (clockwise) in the first area of the pixel, and the electrode elements of the pixel electrode are formed at an angle of +10° (clockwise) in the first area of the pixel. The elements are formed to form an angle of -10° (clockwise). That is, in the first region and the second region of each pixel, the directions of rotational motion (in-plane switching) of the liquid crystal within the substrate surface caused by application of voltage between the pixel electrode and the opposing electrode are opposite to each other. It is structured as such.

After filtering the liquid crystal aligning agent obtained by the method mentioned above with a 1.0-micrometer filter, an ITO film is formed into a film on the back surface as the prepared said electrode-attached board|substrate and an opposing board|substrate, and also a columnar spacer with a height of 4 micrometers is formed. A polyimide film can be obtained on each substrate as a coating film with a thickness of 70 nm or more by spin coating on each of the glass substrates, drying on a hot plate at 80°C for 5 minutes, and then baking at 230°C for 30 minutes. 0.01 J to 1 J/cm ² of ultraviolet rays with a wavelength of 200 to 300 nm are irradiated on this polyimide film in a predetermined orientation direction, and then dried at 230°C for 30 minutes.

Using the two types of substrates to which the liquid crystal alignment film is attached, they are combined so that their respective orientation directions are antiparallel, and the surrounding area is sealed leaving a liquid crystal injection port, thereby producing an empty cell with a cell gap of 3.6 μm. After vacuum injecting liquid crystal (MLC-2041, manufactured by Merck & Co., Ltd.) into this empty cell at room temperature, the injection port is sealed to form a liquid crystal cell with anti-parallel orientation. The obtained liquid crystal cell constitutes an IPS mode liquid crystal display element. After this, a liquid crystal alignment cell can be obtained by heating the obtained liquid crystal cell at 110 degreeC for 1 hour and leaving it to stand overnight.

(Example 33)

About the liquid crystal aligning agent (A-1) obtained in Example 1, a liquid crystal evaluation cell (E-1) was manufactured according to the procedure mentioned above.

(Examples 34 to 46, Comparative Examples 7 and 8)

The liquid crystal aligning agent (A-2) - (A-14), (B-1), and (B-2) obtained after Example 2 was operated similarly to Example 33, and cell for evaluation (E -2) to (E-14), (F-1), and (F-2) were prepared.

(Example 47)

The liquid crystal evaluation cell (E-1) obtained in Example 33 was subjected to afterimage evaluation by long-term driving. The afterimage evaluation method by long-term alternating current drive is as follows.

(Afterimage evaluation by long-term operation)

In a constant temperature environment of 60°C, an alternating voltage of 8 VPP was applied at a frequency of 30 Hz for 100 hours. After that, the space between the pixel electrode of the liquid crystal cell and the counter electrode was short-circuited, and the liquid was left at room temperature for one day.

After leaving, the liquid crystal cell was installed between two polarizing plates arranged so that the polarization axes were orthogonal, the backlight was turned on in a voltage-free state, and the arrangement angle of the liquid crystal cell was adjusted so that the luminance of transmitted light was minimal. And the rotation angle when the liquid crystal cell was rotated from the angle at which the second area of the first pixel becomes darkest to the angle at which the first area becomes darkest was calculated as angle Δ. Similarly, in the second pixel, the second area and the first area were compared, and the same angle Δ was calculated. And the average value of the angle Δ values of the first pixel and the second pixel was calculated as the angle Δ of the liquid crystal cell. When the value of the angle Δ of this liquid crystal cell exceeded 0.2 degrees, it was defined as “defective” and evaluated. When the value of the angle Δ of this liquid crystal cell did not exceed 0.2 degrees, it was defined as “good” and evaluated. The evaluation results are shown in Table 2.

(Examples 48 to 60, Comparative Examples 7 and 8)

The same operation as Example 47 was carried out for liquid crystal evaluation cells (E-2) to (E-14), (F-1), and (F-2) obtained in Examples 34 to 46 and Comparative Examples 7 to 8. was carried out, and afterimage evaluation during long-term alternating current operation was performed. The measurement results are shown in Table 2.

(Example 61)

The liquid crystal evaluation cell (E-1) obtained in Example 33 was subjected to afterimage evaluation by alternating current drive + direct current drive. The afterimage evaluation method is as follows.

(Afterimage evaluation)

Afterimage evaluation was performed using the following optical system.

The manufactured liquid crystal cell was installed between two polarizing plates arranged so that the polarization axes were orthogonal, the LED backlight was turned on in a voltage-free state, and the arrangement angle of the liquid crystal cell was adjusted so that the luminance of transmitted light was minimal.

Next, the V-T curve (voltage-transmittance curve) was measured while applying an alternating voltage with a frequency of 30 Hz to this liquid crystal cell, and the alternating voltage at which the relative transmittance was 23% was calculated as the driving voltage.

In the afterimage evaluation, an alternating current voltage with a frequency of 30 Hz with a relative transmittance of 23% was applied to drive the liquid crystal cell, while a 1 V direct current voltage was simultaneously applied and driven for 60 minutes. After that, the applied direct current voltage value was set to 0 V, only the application of the direct current voltage was stopped, and the vehicle was driven in that state for an additional 30 minutes.

The afterimage evaluation was defined as “good” when the relative transmittance recovered to 25% or less by the time 60 minutes had elapsed from the time the application of direct current voltage was stopped. In cases where it took more than 30 minutes for the relative transmittance to recover to 25% or less, it was defined as “defective” and evaluated.

And the afterimage evaluation according to the method mentioned above was performed under the temperature conditions in which the temperature of the liquid crystal cell was 23 degreeC. The obtained results are shown in Table 2.

(Examples 62 to 74, Comparative Examples 9 and 10))

The same operation as in Example 47 was performed on the liquid crystal evaluation cells (E-2) to (E-14), (F-1), and (F-2) obtained in Examples 34 to 46 and Comparative Examples 7 and 8. And, afterimage evaluation during alternating current + direct current driving was performed. The measurement results are shown in Table 2.

Industrial applicability

The liquid crystal display element manufactured using the liquid crystal aligning agent of the present invention has excellent display quality and reliability, and can be widely used for large-screen, high-definition liquid crystal televisions and smart phones.

In addition, the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2015-152600 filed on July 31, 2015 are hereby cited and accepted as disclosure of the specification of the present invention.

Claims (13)

A liquid crystal aligning agent characterized by containing a polyamic acid ester component (A) having a repeating unit represented by the following formula (1) and a repeating unit represented by the formula (2), and a polyamic acid component (B).

(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms. R ² to R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Y ¹ is represented by the following formula (Y ^1-2 ) Y ² is a divalent organic group represented by the following formula (Y ² -1).

(In the formula, A ¹ and A ⁵ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms. A ² and A ⁴ are each independently an alkylene group having 1 to 5 carbon atoms. A ³ is an alkylene group having 1 to 6 carbon atoms, or B ¹ and B ² are each independently a single bond, -O-, -NH-, -NMe-, -C(=O)-, -. C(=O)O-, -C(=O)NH-, -C(=O)NMe-, -OC(=O)-, -NHC(=O)-, or -N(Me)C( =O)-. D ₁ is a tert-butoxycarbonyl group or 9-fluorenylmethoxycarbonyl group. a is 0 or 1, and n is an integer of 2 to 6. According to claim 1,
The content ratio of the polyamic acid ester (A) component and the polyamic acid (B) component is 1/9 to 9/1 in mass ratio (A/B), and the total solid concentration of the above (A) component and (B) component. A, 0.5 to 10% by mass of liquid crystal aligning agent. According to claim 1,
The liquid crystal aligning agent whose repeating unit of Formula (1) in the polyamic acid ester (A) component is 5-60 mol% with respect to all repeating units. According to claim 1,
The liquid crystal aligning agent whose repeating unit of Formula (2) in the polyamic acid ester (A) component is 10-70 mol% with respect to all repeating units. According to claim 1,
A liquid crystal aligning agent in which the polyamic acid ester (A) component has a repeating unit further represented by the following formula (3) in addition to the above-described repeating unit.

(Wherein, R ¹ to R ⁵ are the same as those in the above formulas (1) and (2), and Y ³ is a divalent organic group represented by the following formula (Y-7).)

According to claim 5,
The liquid crystal aligning agent whose repeating unit of Formula (3) in the polyamic acid ester (A) component is 30 to 50 mol% with respect to all repeating units of the polyamic acid ester (A) component. According to claim 1,
A liquid crystal aligning agent in which R ² and R ⁴ in the repeating unit represented by the above formula (1) are methyl groups. According to claim 1,
A liquid crystal aligning agent in which the polyamic acid (B) component is obtained by making the tetracarboxylic dianhydride component and diamine component represented by the following formula (4) react.

(In the formula, X is a tetravalent organic group represented by at least one selected from the following.)

According to claim 1,
The liquid crystal aligning agent in which the content rate of N-methyl-2-pyrrolidone contains the organic solvent of 30-50 mass % with respect to the total weight of the liquid crystal aligning agent. According to claim 1,
Photo-alignment treatment liquid crystal alignment film, liquid crystal alignment agent. A liquid crystal aligning film obtained from the liquid crystal aligning agent according to any one of claims 1 to 10. A liquid crystal display element having the liquid crystal alignment film according to claim 11. A method for producing a liquid crystal alignment film in which the liquid crystal aligning agent according to any one of claims 1 to 10 is applied onto a substrate with an electrode and subjected to photo-alignment treatment.