KR102488715B1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

(X₁, X₂ : 식 (X1-1) 또는 (X1-2), R₁, R₂, R₃, R₄, 및 R₆ 은 각각 독립적으로 수소 원자, 또는 탄소수 1 ∼ 4 의 알킬기이다. R₅ 는 탄소수 1 ∼ 4 의 알킬기이다. n 은 1 ∼ 6 의 정수이다.)
[화학식 2]

A liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element for obtaining an alignment film suitable for photo-alignment in which no luminescent point occurs even in a negative liquid crystal and good afterimage characteristics are obtained are provided.
A liquid crystal alignment containing at least one kind of polymer (A) selected from the group consisting of a polyimide precursor having a structural unit represented by formula (1) and a structural unit represented by formula (2), and an imidized polymer of the polyimide precursor My.
[Formula 1]

(X ₁ , X ₂ : formula (X1-1) or (X1-2), R ₁ , R ₂ , R ₃ , R ₄ , and R ₆ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms .R ₅ is an alkyl group having 1 to 4 carbon atoms. n is an integer of 1 to 6.)
[Formula 2]

Description

A liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element {LIQUID CRYSTAL ALIGNMENT AGENT, LIQUID CRYSTAL ALIGNMENT FILM, AND LIQUID CRYSTAL DISPLAY ELEMENT}

This invention relates to the liquid crystal display element using the liquid crystal aligning agent suitable for a photo-alignment method process, the liquid crystal aligning film obtained from this liquid crystal aligning agent, and this liquid crystal aligning film.

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 arrangement of liquid crystals is usually formed inside the element. As the liquid crystal alignment film, a polyimide-based liquid crystal alignment film obtained by applying a liquid crystal aligning agent containing a polyimide precursor such as polyamic acid (polyamic acid) or a solution of soluble polyimide as a main component to a glass substrate or the like and firing is mainly used. According to the currently most popular method industrially, this liquid crystal alignment film is subjected to a so-called rubbing treatment in which the surface of a polyimide liquid crystal alignment film formed on an electrode substrate is rubbed in one direction with a cloth such as cotton, nylon, or polyester. It is manufactured by doing.

The photo-alignment method, as a rubbingless alignment treatment method, has an advantage that it can be produced with an industrially simple manufacturing process.

In the liquid crystal display element of the IPS (In Plane Switching) driving method or the FFS (Fringe Field Switching) driving method, by using the liquid crystal alignment film obtained by the optical alignment method, the contrast of the liquid crystal display element is improved compared to the liquid crystal alignment film obtained by the rubbing treatment method. Since it is possible to improve the performance of a liquid crystal display element from which an improvement in viewing angle characteristics can be expected, it is attracting attention as a promising liquid-crystal alignment treatment method.

However, the liquid crystal aligning film obtained by the photo-alignment method has a problem that the anisotropy with respect to the alignment direction of the polymer film is small compared to that obtained by the rubbing process. When anisotropy is small, sufficient liquid-crystal orientation is not obtained, and when it is set as a liquid crystal display element, problems, such as generation|occurence|production of an afterimage, arise. As a method of increasing the anisotropy of the liquid crystal aligning film obtained by the photo-alignment method, removing the low-molecular-weight component produced by cutting the main chain of the polyimide by light irradiation after light irradiation has been proposed.

Japanese Unexamined Patent Publication No. 9-297313 Japanese Unexamined Patent Publication No. 2011-107266

「Liquid Crystal Optical Alignment Film」, Functional Materials, November 1997, Vol.17, No.11 pp. 13-22

In a liquid crystal display element of an IPS drive system or an FFS drive system, a positive type liquid crystal is conventionally used, but by using a negative type liquid crystal, it is possible to reduce the transmission loss at the top of the electrode and improve the contrast. When the liquid crystal alignment film obtained by the photo-alignment method is used for a liquid crystal display element of an IPS drive system or an FFS drive system using a negative liquid crystal material, it is expected to have higher display performance than conventional liquid crystal display elements.

However, as a result of investigation by the present inventors, it was found that the liquid crystal alignment film obtained by the photo-alignment method has a high incidence of display defects (bright spots) in the case of a liquid crystal display element using a negative liquid crystal material, resulting in a problem of causing display defects. there was.

The subject of this invention is obtained from the liquid crystal aligning agent suitable for the photo-alignment method process for obtaining the liquid crystal aligning film for photo-alignment methods in which a luminescent point does not generate|occur|produce even when negative type liquid crystal is used and favorable afterimage characteristics are obtained, and the liquid crystal aligning agent It is providing the liquid crystal display element provided with a liquid crystal aligning film and its liquid crystal aligning agent.

As a result of earnestly advancing research, this inventor discovered that the liquid crystal aligning agent containing the polyimide-type polymer which has a specific structure was effective in order to achieve the said objective, and came to complete this invention.

The present invention contains at least one polymer (A) selected from the group consisting of a polyimide precursor having structural units represented by the following formula (1) and the following formula (2) and an imidized polymer of the polyimide precursor It is in the liquid crystal aligning agent characterized in that.

[Formula 1]

(In formulas (1) and (2), X ₁ and X ₂ are each independently at least one selected from the group consisting of structures represented by the following formulas (X1-1) and (X1-2). R ₁ , R ₂ , R ₃ , R ₄ , and R ₆ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ₅ is an alkyl group having 1 to 4 carbon atoms. n is an integer of 1 to 6.)

[Formula 2]

ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal aligning agent suitable for the photo-alignment method process can be provided which can suppress the bright spot seen by the conventional photo-alignment method, and can obtain the liquid crystal aligning film which has high irradiation sensitivity and has favorable afterimage characteristics. . By providing a liquid crystal aligning film obtained from such a liquid crystal aligning agent, there is no display defect and a highly reliable liquid crystal display element can be provided.

<specific polymer>

The liquid crystal aligning agent of the present invention is at least one selected from the group consisting of a polyimide precursor having a structural unit represented by the following formula (1) and the following formula (2) and an imidized polymer of the polyimide precursor as described above. A polymer (in the present invention, it is also referred to as a specific polymer (A)) is contained. In the present invention, the structural unit represented by the formula (1) and the structural unit represented by the following formula (2) may exist in the same polyimide precursor, or the structural unit represented by the formula (1) and the structural unit represented by the following formula (2) The structural unit shown may exist in another polyimide precursor.

[Formula 3]

Each definition of X ₁ , X ₂ , R ₁ , R ₂ in the formulas (1) and (2) is as described above. Especially, it is preferable that _X1 and X2 have the said formula (X1-2) from the point of _high sensitivity and liquid-crystal orientation. It is preferable that _R1 and _R2 are a hydrogen atom, a methyl group, or an ethyl group from the point of the ease of imidation by heating. R ₃ , R ₄ , and R ₆ are preferably hydrogen atoms in terms of liquid crystal orientation. R ₅ is preferably a methyl group from the viewpoint of liquid crystal orientation. Moreover, it is preferable that n is an integer of 1-3, especially 2 from the point of liquid-crystal orientation.

<Manufacture of polyimide precursor-manufacture of polyamic acid>

The polyamic acid which is a polyimide precursor which has the structural unit represented by Formula (1) in this invention and the structural unit represented by Formula (2) is manufactured by the following method. In addition, in this invention, the polyimide precursor which has a structural unit represented by Formula (1) and the polyimide precursor which has a structural unit represented by Formula (2) are manufactured separately, respectively, and may be manufactured by mixing both.

Further, as tetracarboxylic acid or its dianhydride and diamine to be subjected to condensation polymerization, at least one type of diamine giving a structural unit represented by formula (1) and diamine giving a structural unit represented by formula (2) are each used, It is preferable to manufacture the polyimide precursor which has the structural unit represented by Formula (1) and the structural unit represented by Formula (2).

In this case, tetracarboxylic acid or its dianhydride giving X ₁ in the formula (1) and tetracarboxylic acid or its dianhydride giving X ₂ in the formula (2), Y ₁ A polycondensation reaction of a diamine giving and a diamine giving Y ₂ in the presence of a solvent at -20 to 150°C, preferably 0 to 50°C for 30 minutes to 24 hours, preferably 1 to 12 hours manufactured by doing

Reaction of diamine and tetracarboxylic acid is normally performed in a solvent. The solvent used in that case is not particularly limited as long as the produced polyimide precursor dissolves therein. Although the specific example of the solvent used for reaction is illustrated below, it is not limited to these examples.

For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide or and 1,3-dimethyl-imidazolidinone. Moreover, when the solvent solubility of a polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or following formula [D-1] - formula [D -3] can be used.

[Formula 4]

(In formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, in formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-3], D ³ represents an alkyl group having 1 to 4 carbon atoms)

These solvents may be used alone or in combination. In addition, even if it is a solvent that does not dissolve the polyimide precursor, you may mix it with the said solvent and use it in the range in which the produced|generated polyimide precursor does not precipitate. In addition, since moisture in the solvent inhibits the polymerization reaction and consequently causes the produced polyimide precursor to be hydrolyzed, it is preferable to use a solvent obtained by dehydration and drying.

In addition, in order to obtain polyamic acid alkyl ester, a method of polycondensing a tetracarboxylic acid obtained by dialkyl esterifying a carboxylic acid group with a primary or secondary diamine compound, or a tetracarboxylic acid group obtained by dialkyl esterifying a carboxylic acid group A method of polycondensing an acid dihalide and a primary or secondary diamine compound or a method of converting a carboxyl group of polyamic acid into an ester is used.

When the diamine component and the tetracarboxylic acid component are reacted in a solvent, a solution in which the diamine component is dispersed or dissolved in a solvent is stirred, and the tetracarboxylic acid component is added as it is or after being dispersed or dissolved in a solvent. A method of adding a diamine component to a solution obtained by dispersing or dissolving a boxylic acid component in a solvent, a method of alternately adding a diamine component and a tetracarboxylic acid component, and the like may be used, and any of these methods may be used. Moreover, when reacting using multiple types of a diamine component or a tetracarboxylic acid component, respectively, you may react in the state which was mixed beforehand, or you may make it react one by one individually, or you may mix-react low-molecular-weight substances individually reacted and make a polymer. You can do it.

As the polymerization temperature at that time, an arbitrary temperature of -20 to 150°C can be selected, but is preferably in the range of -5 to 100°C. In addition, although the reaction can be carried out at an arbitrary concentration, when the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and when the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult. Therefore, it is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction can be performed at a high concentration, and then a solvent can be added.

In the polymerization reaction of the polyimide precursor, the ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component is preferably from 0.8 to 1.2, particularly preferably from 0.9 to 1.0. Similar to a typical polycondensation reaction, the closer this molar ratio is to 1.0, the higher the molecular weight of the polyimide precursor produced.

The polyimide in the present invention is a polyimide obtained by cyclization of the polyimide precursor, and in order to obtain the polyimide, a method of cyclizing the polyamic acid or polyamic acid alkyl ester to obtain a polyimide is used.

The polyimide of the present invention has an amide acid group ring closure rate (also referred to as an imidization rate), which is not necessarily 100%, and can be arbitrarily adjusted depending on the use or purpose, and is preferably 50 to 80%.

As a method of imidating the polyimide precursor, thermal imidation in which the solution of the polyimide precursor is heated as it is or catalyst imidation in which a catalyst is added to the solution of the polyimide precursor is exemplified. The temperature in the case of thermal imidation of the polyimide precursor in the solution is 100 to 400°C, preferably 120 to 250°C, and it is preferable to carry out the imidation reaction while removing water generated by the imidation reaction out of the system. As for reaction time, 30 minutes - 4 hours are preferable.

Catalytic imidation of the polyimide precursor can be performed by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring at -20 to 250°C, preferably 0 to 180°C. As for reaction time, 30 minutes - 4 hours are preferable.

The amount of the basic catalyst is 0.5 to 30 mole times, preferably 2 to 20 mole times the amount of the amide acid group, and the amount of the acid anhydride is 1 to 50 mole times, preferably 3 to 30 mole times the amount of the amide acid group. Basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine or trioctylamine. Among them, pyridine is preferable because it has a basicity suitable for advancing the reaction.

As an acid anhydride, acetic anhydride, trimellitic anhydride, or pyromellitic anhydride is mentioned. Among them, the use of acetic anhydride is preferable because purification after completion of the reaction becomes easy. The imidation rate by catalyst imidation is controllable by adjusting the catalyst amount, reaction temperature, and reaction time.

What is necessary is just to throw in the reaction solution into a solvent and just to precipitate it, when collect|recovering the polyimide precursor or polyimide produced|generated from the polyimide precursor or the reaction solution of polyimide. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by pouring into the solvent can be collected by filtration and then dried at normal temperature or under reduced pressure by heating. In addition, impurities in the polymer can be reduced by re-dissolving the polymer recovered by precipitation in a solvent and repeating the operation of re-precipitation and recovery 2 to 10 times. Examples of the solvent at this time include alcohols, ketones, hydrocarbons, and the like, and it is preferable to use three or more types of solvents selected from among these, since the efficiency of purification is further increased.

It is preferable to use polyamic acid alkyl ester for the specific polymer (A) of this invention. Preferable specific methods for producing alkyl polyamic acid are shown in (1) to (3) below.

(1) Manufacturing method by esterification of polyamic acid

This is a method of producing a polyamic acid alkyl ester by producing a polyamic acid from a diamine component and a tetracarboxylic acid component, and subjecting the carboxyl group (COOH group) to a chemical reaction, that is, an esterification reaction.

Specifically, the esterification reaction is performed by mixing polyamic acid and an esterifying agent in the presence of a solvent, preferably at -20 to 150°C, more preferably at 0 to 50°C, preferably for 30 minutes to 24 hours, and more It is made to react preferably for 1 to 4 hours.

The esterifying agent is preferably one that can be easily removed after the esterification reaction, and N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl Acetal, N,N-dimethylformamidedineopentylbutylacetal, N,N-dimethylformamidedi-t-butylacetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyl triazene, 1-propyl-3-p-tolyltriazene, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, etc. there is. The amount of the esterifying agent used is preferably 2 to 6 molar equivalents per mol of the repeating unit of the polyamic acid. Especially, 2-4 molar equivalents are preferable.

Examples of the solvent used for the esterification reaction include solvents used for the reaction between the diamine component and the tetracarboxylic acid component in view of the solubility of the polyamic acid in the solvent. Especially, N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or (gamma)-butyrolactone is preferable. You may use a solvent 1 type or in mixture of 2 or more types.

The concentration of the polyamic acid in the solvent in the esterification reaction is preferably from 1 to 30% by mass from the viewpoint that precipitation of the polyamic acid hardly occurs. Especially, 5-20 mass % is preferable.

(2) Method for producing by reaction of diamine component and tetracarboxylic acid diester dichloride

The reaction between the diamine component and the tetracarboxylic diester dichloride is, specifically, the diamine component and the tetracarboxylic diester dichloride in the presence of a base and a solvent, preferably -20 to 150 ° C., more preferably It is a method of reacting at 0 to 50°C, preferably for 30 minutes to 24 hours, and more preferably for 1 to 4 hours.

Pyridine, triethylamine, 4-dimethylaminopyridine, etc. can be used for the said base. Among them, pyridine is preferable because the reaction proceeds mildly. The amount of base used is preferably an amount that can be easily removed after the reaction, and is preferably 2 to 4 times the mole of tetracarboxylic acid diester dichloride. Especially, 2-3 times mole is more preferable.

As for the solvent used for the said reaction, the solvent used for reaction of the said diamine component and the tetracarboxylic acid component is mentioned from the point of solubility to the solvent of the polymer obtained, ie, polyamic-acid alkylester. Especially, N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or (gamma)-butyrolactone is preferable. You may use these solvents 1 type or in mixture of 2 or more types.

The concentration of the polyamic acid alkyl ester in the solvent in the above reaction is preferably from 1 to 30% by mass from the viewpoint that precipitation of the polyamic acid alkyl ester hardly occurs. Especially, 5-20 mass % is preferable. Further, in order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, it is preferable that the solvent used for production of the polyamic acid alkyl ester is dehydrated as much as possible. In addition, it is preferable to carry out the reaction in a nitrogen atmosphere and to prevent mixing of outside air.

(3) Method for manufacturing by reaction of diamine component and tetracarboxylic acid diester

It is a method for producing by a polycondensation reaction of a diamine component and a tetracarboxylic diester, specifically, diamine component and tetracarboxylic diester in the presence of a condensing agent, a base and a solvent, preferably at 0 to 150 ° C. , More preferably, it is a method of reacting at 0 to 100°C, preferably for 30 minutes to 24 hours, and more preferably for 3 to 15 hours.

The condensing agent includes triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldiimidazole, dimethoxy-1 ,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(benzotriazole- 1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzooxazolyl)phosphonic acid diphenyl, etc. can The amount of condensing agent used is preferably 2 to 3 moles, particularly preferably 2 to 2.5 moles, based on the tetracarboxylic acid diester.

Tertiary amines such as pyridine and triethylamine can be used for the base. The amount of the base used is preferably an amount that can be easily removed after the polycondensation reaction, and is preferably 2 to 4 moles, particularly preferably 2 to 3 moles with respect to the diamine component.

As for the solvent used for the polycondensation reaction, the solvent used for the reaction between the diamine component and the tetracarboxylic acid component is exemplified in view of the solubility of the polyamic acid alkyl ester, which is the resulting polymer, in the solvent. In particular, N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. A solvent may mix and use 2 or more types.

Moreover, in the said polycondensation reaction, reaction advances 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 the Lewis acid used is preferably 0.1 to 10 moles, more preferably 2.0 to 3.0 moles, relative to the amount of the diamine component.

In the case of recovering the polyamic acid alkyl ester from the polyamic acid alkyl ester solution obtained by the methods (1) to (3) above, the reaction solution may be introduced into a solvent to precipitate. Water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned as a solvent used for precipitation. The polymer precipitated by being put into a solvent is preferably subjected to a washing operation with the solvent a plurality of times for the purpose of removing the additives/catalysts used above. After collecting by filtration, it can be dried by heating or at room temperature under normal pressure or reduced pressure. In addition, impurities in the polymer can be reduced by re-dissolving the polymer recovered by precipitation in a solvent and repeating the operation of re-precipitation and recovery 2 to 10 times. As the solvent at this time, a solvent in which the polymer is dissolved is exemplified.

For the polyamic acid alkyl ester of the present invention, the method (1) or (2) is preferable among the methods (1) to (3) above.

<liquid crystal aligning agent>

A liquid crystal aligning agent is a coating solution for forming a liquid crystal aligning film (it is also referred to as a resin film), and is a coating solution for forming a liquid crystal aligning film containing a specific polymer (A) and a solvent. Although content of the specific polymer (A) in a liquid crystal aligning agent can be suitably changed according to the coating method of a liquid crystal aligning agent, or the film thickness of the liquid crystal aligning film made into the objective, it is preferable that it is 2-10 mass %, especially 3-7 mass % is preferred. On the other hand, it is preferable that it is 70-99.9 mass %, and, as for content of a solvent, 90-98 mass % is more preferable.

The solvent used for the liquid crystal aligning agent of this invention is a solvent (it is also mentioned a good solvent) in which a specific polymer (A) is dissolved, and an organic solvent is especially preferable. Although the specific example of a good solvent is illustrated below, it is not limited to these examples.

For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, etc. are mentioned. Especially, it is preferable to use N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone.

Moreover, when the solubility to the solvent of a specific polymer (A) is high, it is preferable to use the solvent represented by the said formula [D-1] - formula [D-3].

It is preferable that it is 20-99 mass % of the whole solvent, as for the good solvent in a liquid crystal aligning agent, 20-90 mass % is more preferable, and its 30-80 mass % is especially preferable.

The liquid crystal aligning agent can contain a solvent (also referred to as a poor solvent) that improves the coating properties and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied, unless the effect of the present invention is impaired. As for these poor solvents, 1-80 mass % of the whole solvent contained in a liquid crystal aligning agent is preferable. Especially, 10-80 mass % is preferable. More preferably, it is 20-70 mass %.

Although the specific example of a poor solvent is illustrated below, it is not limited to these examples. For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, Isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1- Butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methyl Cyclohexanol, 3-methylcyclohexanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, Ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl Ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl Acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2-(methoxymethoxy)ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-( Hexyloxy)ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1-(butoxyethoxy)propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether , dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol di Acetate, diethylene glycol monoethyl ether acetate diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, lactic acid Ethyl, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, 3-methoxymethyl propionate, 3-ethoxymethylethylpropionate, 3-methoxyethylpropionate, 3- Ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropylpropionate, 3-methoxybutylpropionate, methyl lactate, ethyl lactate, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester, The solvent etc. represented by said formula [D-1] - formula [D-3] are mentioned.

Among them, it is preferable to use 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether. .

In the liquid crystal aligning agent of the present invention, a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group or a cyclocarbonate group, a crosslinking compound having at least one substituent selected from the group consisting of a hydroxyl group, a hydroxyalkyl group and a lower alkoxyalkyl group. It is preferable to introduce a polymerizable compound or a crosslinkable compound having a polymerizable unsaturated bond. It is necessary to have two or more of these substituents and polymerizable unsaturated bonds in a crosslinkable compound.

Examples of the crosslinkable compound having an epoxy group or an isocyanate group include bisphenol acetone glycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, triglycidyl isocyanurate, and tetraglycidylaminodiphenylene. , tetraglycidyl-m-xylenediamine, tetraglycidyl-1,3-bis(aminoethyl)cyclohexane, tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, bisphenol hexafluoroacetate Diglycidyl ether, 1,3-bis(1-(2,3-epoxypropoxy)-1-trifluoromethyl-2,2,2-trifluoromethyl)benzene, 4,4-bis( 2,3-epoxypropoxy)octafluorobiphenyl, triglycidyl-p-aminophenol, tetraglycidylmethaxylenediamine, 2-(4-(2,3-epoxypropoxy)phenyl)-2- (4-(1,1-bis(4-(2,3-epoxypropoxy)phenyl)ethyl)phenyl)propane, 1,3-bis(4-(1-(4-(2,3-epoxypropoxy) Poxy)phenyl)-1-(4-(1-(4-(2,3-epoxypropoxy)phenyl)-1-methylethyl)phenyl)ethyl)phenoxy)-2-propanol and the like.

A crosslinkable compound having an oxetane group is a compound having at least two oxetane groups represented by the following formula [4A].

[Formula 5]

Specifically, the crosslinkable compound represented by formula [4a] - formula [4k] published on pages 58-59 of international publication WO2011/132751 (published on October 27, 2011) is mentioned.

The crosslinkable compound having a cyclocarbonate group is a crosslinkable compound having at least two cyclocarbonate groups represented by the following formula [5A].

[Formula 6]

Specifically, crosslinkable compounds represented by formula [5-1] to formula [5-42] published on pages 76 to 82 of International Publication No. WO2012/014898 (published on February 2, 2012) are exemplified.

Examples of the crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group and an alkoxy group include an amino resin having a hydroxyl group or an alkoxy group, such as melamine resin, urea resin, and guanamine resin, glycoluril-formaldehyde resin, succinylamide-formaldehyde resin, ethyleneurea-formaldehyde resin and the like. Specifically, a melamine derivative, a benzoguanamine derivative, or a glycoluril in which the hydrogen atom of the amino group is substituted with a methylol group or an alkoxymethyl group or both thereof can be used. This melamine derivative or benzoguanamine derivative may exist as a dimer or a trimer. It is preferable that these have an average of 3 or more and 6 or less methylol groups or alkoxymethyl groups per triazine ring.

Examples of the melamine derivative or benzoguanamine derivative are commercially available MX-750 in which an average of 3.7 methoxymethyl groups per triazine ring is substituted, and MW-750 in which an average of 5.8 methoxymethyl groups per triazine ring is substituted. 30 (above, manufactured by Sanwa Chemical Co., Ltd.), methoxymethylated melamine such as Cymel 300, 301, 303, 350, 370, 771, 325, 327, 703, 712, Cymel 235, 236, 238, 212, 253, Methoxymethylated butoxymethylated melamine such as No. 254, butoxymethylated melamine such as Cymel 506 and 508, methoxymethylated isobutoxymethylated melamine containing a carboxyl group such as Cymel 1141, methoxymethylated ethoxymethylated such as Cymel 1123 Benzoguanamines, methoxymethylated butoxymethylated benzoguanamines such as Cymel 1123-10, butoxymethylated benzoguanamines such as Cymel 1128, methoxymethylated ethoxymethylated benzoguas containing carboxyl groups such as Cymel 1125-80 Namine (above, manufactured by Mitsui Cyanamide Co., Ltd.) is exemplified. Moreover, as an example of glycoluril, butoxymethylation glycoluril like Cymel 1170, methylolation glycoluril like Cymel 1172, methoxymethylolation glycoluril like Powder Link 1174, etc. are mentioned.

Examples of the benzene or phenolic compound having a hydroxy group or an alkoxy group include 1,3,5-tris(methoxymethyl)benzene, 1,2,4-tris(isopropoxymethyl)benzene, 1, 4-bis(sec-butoxymethyl)benzene or 2,6-dihydroxymethyl-p-tert-butylphenol.

More specifically, the crosslinkable compound of formula [6-1] - formula [6-48] published on pages 62-66 of international publication WO2011/132751 (published on October 27, 2011) is mentioned.

Examples of the crosslinkable compound having a polymerizable unsaturated bond include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and tri(meth)acrylate. ) crosslinkable compounds having three polymerizable unsaturated groups in the molecule, such as acryloyloxyethoxytrimethylolpropane and glycerin polyglycidyl ether poly(meth)acrylate; Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol Di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide bisphenol A type di(meth)acrylate, propylene oxide bisphenol type di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol digly Crosslinkable compounds having two polymerizable unsaturated groups in the molecule, such as cydyl ether di(meth)acrylate, phthalic acid diglycidyl ester di(meth)acrylate, and hydroxypivalic acid neopentyl glycol di(meth)acrylate ; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2 -(meth)acryloyloxy-2-hydroxypropylphthalate, 3-chloro-2-hydroxypropyl (meth)acrylate, glycerin mono(meth)acrylate, 2-(meth)acryloyloxyethyl phosphate crosslinkable compounds having one polymerizable unsaturated group in the molecule, such as ester and N-methylol (meth)acrylamide; etc. can be mentioned.

Moreover, the compound represented by following formula [7A] can also be used.

[Formula 7]

(In formula [7A], E ₁ is a group selected from the group consisting of a cyclohexane ring, a bicyclohexane ring, a benzene ring, a biphenyl ring, a terphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, and a phenanthrene ring E ₂ represents a group selected from the following formulas [7a] and formula [7b], and n represents an integer of 1 to 4.)

[Formula 8]

The above is an example of a crosslinkable compound, and is not limited thereto. Moreover, 1 type may be sufficient as the crosslinkable compound used for the liquid crystal aligning agent of this invention, and you may combine it 2 or more types.

As for content of the crosslinkable compound in the liquid crystal aligning agent of this invention, 0.1-150 mass parts is preferable with respect to 100 mass parts of all polymer components. Among them, 0.1 to 100 parts by mass is preferable with respect to 100 parts by mass of all the polymer components in order to promote the crosslinking reaction and express the target effect. More preferably, it is 1-50 mass parts.

The liquid crystal aligning agent of this invention can use the compound which improves the uniformity of the film thickness and surface smoothness of the liquid crystal aligning film at the time of apply|coating a liquid crystal aligning agent, unless the effect of this invention is impaired.

As a compound which improves the uniformity and surface smoothness of the film thickness of a liquid crystal aligning film, a fluorochemical surfactant, silicone type surfactant, nonionic surfactant, etc. are mentioned.

More specifically, for example, Ftop EF301, EF303, EF352 (above, manufactured by Tochem Products), Megafac F171, F173, R-30 (above, manufactured by Dainippon Ink Co., Ltd.), Fluorad FC430, FC431 (above, manufactured by Dainippon Ink Co., Ltd.) The above, manufactured by Sumitomo 3M), Asahi Guard AG710, Suffron S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above, manufactured by Asahi Glass), and the like.

The amount of surfactant used is preferably from 0.01 to 2 parts by mass, more preferably from 0.01 to 1 part by mass with respect to 100 parts by mass of all the polymer components contained in the liquid crystal aligning agent.

Further, in the liquid crystal aligning agent, formula [M1] published on pages 69 to 73 of International Publication WO2011/132751 (published on October 27, 2011) as a compound that promotes charge transfer in the liquid crystal alignment film and promotes charge extraction in the element. - A nitrogen-containing heterocyclic amine compound represented by the formula [M156] may be added. Although you may add this amine compound directly to a liquid crystal aligning agent, it is a density|concentration of 0.1-10 mass %, It is preferable to add, after setting it as a 1-7 mass % solution preferably. This solvent is not particularly limited as long as it dissolves the specific polymer (A).

In the liquid crystal aligning agent of the present invention, besides the poor solvent, the crosslinkable compound, the compound that improves the uniformity of the film thickness or the surface smoothness of the resin film or the liquid crystal aligning film, and the compound that promotes charge release, the effect of the present invention is not impaired. As long as it is not a range, you may add the dielectric material or conductive material for the purpose of changing electric characteristics, such as the dielectric constant and conductivity of a liquid crystal aligning film.

<Liquid crystal alignment film/liquid crystal display element>

A liquid crystal aligning film is a film obtained by applying the liquid crystal aligning agent to a substrate, drying it, and baking it. 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 plastic substrates such as acrylic substrates and polycarbonate substrates may be used in addition to glass substrates and silicon nitride substrates. In that case, it is preferable from the point of process simplification to use the board|substrate on which the ITO electrode etc. for driving a liquid crystal were formed. Further, in the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is used for only one substrate, and a material that reflects light such as aluminum can also be used for the electrode in this case.

Although the coating method of a liquid crystal aligning agent is not specifically limited, Industrially, the method of performing by screen printing, offset printing, flexographic printing, an inkjet method, etc. is common. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method, and a spray method, and these may be used depending on the purpose.

After applying the liquid crystal aligning agent on the substrate, the solvent can be evaporated by heating means such as a hot plate, a heat circulation type oven, an IR (infrared ray) type oven, and the liquid crystal alignment film can be obtained. The drying and baking process after apply|coating the liquid crystal aligning agent of this invention can select arbitrary temperature and time. Usually, in order to sufficiently remove the contained solvent, drying is performed at 50 to 120°C, preferably 60 to 100°C for 1 to 10 minutes, preferably 1 to 5 minutes, and thereafter at 150 to 300°C. , Preferably, the conditions of baking at 180-250 degreeC for 5-120 minutes, Preferably, 10-60 minutes are mentioned. Since the reliability of a liquid crystal display element may fall when the thickness of the liquid crystal aligning film after baking is too thin, 5-300 nm is preferable and 10-200 nm is more preferable.

Although the method of orientation-processing the liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention may be a rubbing process method, the photo-alignment process method is preferable. As a preferable example of the photo-alignment treatment method, the surface of the liquid crystal alignment film is irradiated with radiation deflected in a certain direction, and heat treatment is performed at a temperature of preferably 150 to 250 ° C. depending on the case, and the liquid crystal orientation (liquid crystal orientation ability) Also referred to as) may be given. As radiation, ultraviolet rays or visible rays having a wavelength of 100 to 800 nm can be used. Among them, it is an ultraviolet ray having a wavelength of preferably 100 to 400 nm, more preferably 200 to 400 nm.

Moreover, in order to improve liquid-crystal orientation, you may irradiate a radiation, heating the board|substrate on which the liquid crystal aligning film was coated at 50-250 degreeC.

As for the irradiation amount of the said radiation, 1-10,000 mJ/cm<2> is preferable. Especially, 100-5,000 mJ/cm<2> is preferable. The liquid crystal aligning film manufactured in this way can stably orientate liquid crystal molecules in a fixed direction.

Further, in the above method, contact treatment may be performed using water or a solvent on the liquid crystal alignment film irradiated with polarized radiation.

It will not specifically limit, if it is a solvent which melt|dissolves the decomposition product produced|generated from the liquid crystal aligning film by irradiation of a radiation as a solvent used for the said contact process. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate , diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, and the like. Among them, water, 2-propanol, 1-methoxy-2-propanol or ethyl lactate is preferable from the viewpoint of versatility and solvent safety. More preferred are water, 1-methoxy-2-propanol or ethyl lactate. One type of solvent may be used, or two or more types may be combined.

Examples of the contact treatment include immersion treatment and spray treatment (also referred to as spray treatment). It is preferable that the processing time in these processes is 10 second - 1 hour from the point which melt|dissolves the degradation product produced|generated from the liquid crystal aligning film by radiation efficiently. Among them, it is preferable to perform an immersion treatment for 1 to 30 minutes. In addition, the solvent at the time of the said contact treatment may be normal temperature or may be heated, but it is preferably 10-80 degreeC. Especially, 20-50 degreeC is preferable. In addition, from the viewpoint of the solubility of the degraded product, ultrasonic treatment or the like may be performed as necessary.

After the said contact treatment, it is preferable to perform rinsing (it is also mentioned rinse) by low boiling point solvents, such as water, methanol, ethanol, 2-propanol, acetone, and methyl ethyl ketone, and baking of a liquid crystal aligning film. At that time, either one of rinsing and baking may be performed, or both may be performed. The firing temperature is preferably 150 to 300°C. Especially, 180-250 degreeC is preferable. More preferably, it is 200-230 degreeC. Moreover, as for the baking time, 10 second - 30 minutes are preferable. Especially, 1 to 10 minutes are preferable.

The liquid crystal aligning film of the present invention is suitable as a liquid crystal aligning film of a liquid crystal display element of a horizontal electric field system such as an IPS system or a FFS system, and is particularly useful as a liquid crystal alignment film of a liquid crystal display element of an FFS system. A liquid crystal display element manufactures a liquid crystal cell by a known method, after obtaining the board|substrate with a liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention, and is obtained using this liquid crystal cell.

As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Alternatively, it may be a liquid crystal display element having an active matrix structure in which switching elements such as TFT (Thin Film Transistor) are formed in each pixel portion constituting the image display.

Specifically, a transparent glass substrate is prepared, a common electrode is formed on one substrate, and a segment electrode is formed on the other substrate. These electrodes can be, for example, ITO electrodes, and are patterned so that desired image display is possible. Next, an insulating film is formed on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a SiO ₂ -TiO ₂ film formed by a sol-gel method.

Next, a liquid crystal aligning film is formed on each substrate, the other substrate is superimposed on one substrate so that the liquid crystal aligning film surfaces are opposed to each other, and the periphery is bonded with a sealing agent. In order to control the gap between the substrates, the sealant is usually mixed with a spacer, and it is preferable to spread the spacer for controlling the gap between the substrates also in the in-plane portion where the sealant is not formed. An opening portion capable of being filled with liquid crystal from the outside is formed in a part of the sealant. Next, the liquid crystal material is injected into the space surrounded by the two substrates and the sealant through the opening formed in the sealant, and then the opening is sealed with an adhesive. For injection, a vacuum injection method may be used, or a method using capillarity in the air may be used. As the liquid crystal material, either a positive liquid crystal material or a negative liquid crystal material may be used, but a negative liquid crystal material is preferable. Next, the polarizing plate is installed. Specifically, a pair of polarizing plates is attached to the surface of the two substrates on the opposite side to the liquid crystal layer.

As mentioned above, by using the liquid crystal aligning agent of this invention, the liquid crystal aligning film which suppresses the afterimage by an alternating current drive and makes adhesiveness with a sealing compound and a base substrate compatible can be obtained. In particular, it is useful with respect to the liquid crystal alignment film for photo-alignment methods obtained by irradiating polarized radiation.

Example

The present invention will be described in more detail by way of examples below, but the present invention is not limited thereto. The symbol of the compound used below and the measuring method of each characteristic are as follows.

NMP: N-methyl-2-pyrrolidone

BCS: butyl cellosolve

DA-1: 1,2-bis(4-aminophenoxy)ethane

DA-2: 4-(2-(methylamino)ethyl)aniline

DA-3: p-phenylenediamine

DA-4: 4-(2-aminoethyl)aniline

DA-5: Refer to the following formula (DA-5)

[Formula 9]

[Viscosity]

The viscosity of the polyamic acid ester and polyamic acid solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) at a sample amount of 1.1 ml, a cone rotor TE-1 (1 ° 34', R24), and a temperature of 25 ° C. measured.

[Molecular Weight]

The molecular weights of polyamic acid ester etc. were measured with the GPC (normal temperature gel permeation chromatography) apparatus, and computed the number average molecular weight (Mn) and the weight average molecular weight (Mw) as polyethylene glycol and a polyethylene oxide conversion value.

GPC device: manufactured by Shodex (GPC-101), column: manufactured by Shodex (a series of KD803 and KD805), column temperature: 50 ° C, eluent: N, N-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr H ₂ O) is 30 mmol/ℓ, phosphoric acid/anhydrous crystal (o-phosphoric acid) is 30 mmol/ℓ, tetrahydrofuran (THF) is 10 ml/ℓ), flow rate: 1.0 ml/min

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

[Anisotropy of alignment layer]

It measured using the liquid crystal aligning film evaluation system by the Moritex company "Ray-scan Labo H" (LYS-LH30S-1A). A polyimide film having a film thickness of 100 nm was irradiated with ultraviolet light having a wavelength of 254 nm linearly polarized at an extinction ratio of 10:1 or more through a polarizing plate, and the magnitude of anisotropy with respect to the orientation direction of the obtained alignment film was measured.

[Production of liquid crystal cell]

A liquid crystal cell having a configuration of a fringe field switching (FFS) mode liquid crystal display device is manufactured.

First, a substrate on which electrodes were formed was prepared. The substrate is a glass substrate having a size of 30 mm x 50 mm and a thickness of 0.7 mm. On the substrate, as a first layer, an ITO electrode comprising a counter electrode and having a beta-phase pattern is formed. On the counter electrode of the first layer, as a second layer, a SiN (silicon nitride) film formed by the CVD method is formed. The film thickness of the SiN film of the 2nd layer is 500 nm, and it functions as an interlayer insulating film. On the SiN film of the second layer, as the third layer, a comb-shaped pixel electrode formed by patterning the ITO film is disposed, forming two pixels, a first pixel and a second pixel. The size of each pixel is 10 mm in length and about 5 mm in width. 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 pixel electrode of the third layer has a comb-like shape formed by arranging a plurality of ""-shaped electrode elements with bent central portions. The width of each electrode element in the width direction is 3 μm, and the interval between the electrode elements is 6 μm. Since the pixel electrodes constituting each pixel are constituted by arranging a plurality of z-shaped electrode elements with curved central portions, the shape of each pixel is not rectangular, but is curved in the central portion similarly to the electrode element. It has a shape similar to the letter "く" in . Then, each pixel is divided up and down with the central bending part as a boundary, and has a first region above the bending part and a second region below the bending part.

Comparing the 1st area and the 2nd area|region of each pixel, the formation direction of the electrode element of the pixel electrode which comprises them differs. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, the electrode element of the pixel electrode is formed to form an angle of +10 ° (clockwise direction) in the first area of the pixel, and the electrode of the pixel electrode in the second area of the pixel The elements are formed to form an angle of -10° (clockwise). That is, in the first area and the second area of each pixel, directions of rotational motion (in-plane switching) in the substrate plane of the liquid crystal caused by application of a voltage between the pixel electrode and the opposite electrode are opposite to each other. there is.

Next, the liquid crystal aligning agent was filtered through a 1.0 μm filter, and then applied to a glass substrate having a columnar spacer having a height of 4 μm and having an ITO film formed on the prepared substrate and the back surface thereof by spin coating. After drying on an 80 degreeC hot plate for 5 minutes, it baked in a 230 degreeC hot-air circulation type oven for 20 minutes, and the coating film of 100 nm thickness was formed. The coating film surface was irradiated with ultraviolet light having a wavelength of 254 nm that was linearly polarized at an extinction ratio of 10:1 or more through a polarizing plate. This substrate was immersed in at least one solvent selected from water and organic solvents for 3 minutes, then immersed in pure water for 1 minute, and heated on a hot plate at 150 to 300 ° C. for 5 minutes to obtain a substrate with a liquid crystal alignment film. . The above two substrates are set as one set, a sealant is printed on the substrate, and another substrate is attached so that the liquid crystal alignment film faces face each other and the alignment direction is 0 °, and then the sealant is cured to form a blank cell was made. Liquid crystal MLC-7026-100 (manufactured by Merck & Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS drive liquid crystal cell. Then, after heating the obtained liquid crystal cell at 110 degreeC for 1 hour and leaving it to stand overnight, it used for each evaluation.

[Evaluation of afterimage by long-term alternating current drive]

A liquid crystal cell having the same structure as the liquid crystal cell used for the above residual image evaluation was prepared.

Using this liquid crystal cell, an alternating voltage of ±5 V was applied on a frequency of 60 Hz in a 60°C constant temperature environment for 120 hours. Then, it was made into the state which shorted between the pixel electrode of a liquid crystal cell and the counter electrode, and it was left to stand at room temperature for one day as it was.

After standing, the liquid crystal cell was installed between two polarizing plates arranged so that the polarization axes were orthogonal, and the backlight was turned on in a state where no voltage was applied, and the angle of arrangement of the liquid crystal cell was adjusted so that the luminance of the transmitted light was the smallest. And the rotation angle at the time of rotating the liquid crystal cell from the angle at which the 2nd area|region of a 1st pixel becomes the darkest to the angle at which 1st area|region becomes the darkest was computed as angle (DELTA). Similarly, also 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 (triangle|delta) value of a 1st pixel and a 2nd pixel was computed as angle (triangle|delta) of a liquid crystal cell, and liquid-crystal orientation was evaluated by magnitude|size of the value. That is, when the value of this angle Δ is small, the liquid crystal orientation is good.

[Evaluation of bright point of liquid crystal cell (contrast)]

The luminescent point evaluation of the liquid crystal cell manufactured similarly to the above (production of a liquid crystal cell) was performed.

It implemented by observing a liquid crystal cell with a polarization microscope (ECLIPSE E600WPOL) (made by Nikon Corporation). Specifically, a liquid crystal cell was installed with cross nicol, and the number of bright spots confirmed by observing the liquid crystal cell with a polarizing microscope with a magnification of 5 times was counted. If the number of bright spots was less than 10, it was "good", and more than 10 were "bad". made it

<Synthesis Example 1>

Weigh 1.03 g (4.20 mmol) of DA-1, 0.421 g (2.80 mmol) of DA-2, and 0.76 g (7.00 mmol) of DA-3 into a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet pipe. This was added, 33.60 g of NMP was added, and the mixture was dissolved by stirring while conveying nitrogen. While stirring this diamine solution, 2.95 g (13.16 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride is added so that the solid content concentration is 12% by mass. 3.73 g of NMP was added. Then, it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (A). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 316 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn=13530 and Mw=29850.

<Synthesis Example 2>

Weigh 0.95 g (3.90 mmol) of DA-1, 0.98 g (6.5 mmol) of DA-2, and 0.35 g (2.60 mmol) of DA-4 into a 50 ml four-necked flask equipped with a stirring device and a nitrogen inlet tube. This was added, 33.15 g of NMP was added, and the mixture was dissolved by stirring while conveying nitrogen. While stirring this diamine solution, 2.74 g (12.22 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride is added so that the solid content concentration is 12% by mass. 3.73 g of NMP was added. Then, it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (B). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 483 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn=14260 and Mw=30050.

<Synthesis Example 3>

1.47 g (6.00 mmol) of DA-1 and 0.90 g (6.00 mmol) of DA-2 were placed in a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 31.96 g of NMP was added, and nitrogen It was dissolved by stirring while transferring. While stirring this diamine solution, 2.60 g (11.58 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride is added so that the solid content concentration is 12% by mass. 3.55 g of NMP was added. Then, it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (C). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 423 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn=14010 and Mw=29540.

<Synthesis Example 4>

1.59 g (6.50 mmol) of DA-1 and 0.70 g (6.50 mmol) of DA-3 were placed in a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet pipe, 33.01 g of NMP was added, and nitrogen It was dissolved by stirring while transferring. While stirring this diamine solution, 2.78 g (12.42 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride is added so that the solid content concentration is 12% by mass. 3.66 g of NMP was added. Then, it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (D). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 360 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn=13810 and Mw=28400.

<Synthesis Example 5>

Weigh 1.03 g (4.20 mmol) of DA-1, 0.76 g (7.00 mmol) of DA-3, and 0.38 g (2.80 mmol) of DA-4 into a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet pipe. 34.38 g of NMP was added, and the mixture was dissolved by stirring while conveying nitrogen. While stirring this diamine solution, 3.04 g (13.58 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride is added so that the solid content concentration is 12% by mass. 3.82 g of NMP was added. Then, it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (E). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 428 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn=14080 and Mw=29960.

<Synthesis Example 6>

1.13 g (7.50 mmol) of DA-2 and 0.81 g (7.50 mmol) of DA-3 were weighed and placed in a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet pipe, 33.87 g of NMP was added, and nitrogen It was dissolved by stirring while transferring. While stirring this diamine solution, 3.39 g (14.85 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride is added so that the solid content concentration is 12% by mass. 3.76 g of NMP was added. Then, it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (F). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 280 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn=12250 and Mw=26550.

<Synthesis Example 7>

3.36 g (15.00 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was weighed into a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, and NMP was added. 3.73 g was added and dissolved by stirring while conveying nitrogen. While stirring this acid dianhydride solution, 1.13 g (12.68 mmol) of DA-3 and 0.81 g (1.50 mmol) of DA-5 were added, and 7.46 g of NMP was added so that the solid concentration was 10% by mass. did Then, it stirred at room temperature for 24 hours, and obtained the polyamic-acid solution (G). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 460 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn=15020 and Mw=33320.

<Example 1>

15.00 g of a 12 mass % polyamic acid solution (A) was weighed into a 100 ml Erlenmeyer flask, NMP 9.00 g and BCS 6.00 g were added, it was mixed at 25 degreeC for 8 hours, and the liquid crystal aligning agent (1) was obtained. . Abnormality, such as muddiness and precipitation, was not looked at by this liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Example 2>

Except having used 15.00 g of 12 mass % polyamic-acid solutions (B), it carried out similarly to Example 1, and obtained the liquid crystal aligning agent (2). Abnormality, such as muddiness and precipitation, was not looked at by this liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Example 3>

Except having used 15.00 g of 12 mass % polyamic-acid solutions (C), it carried out similarly to Example 1, and obtained the liquid crystal aligning agent (3). Abnormality, such as muddiness and precipitation, was not looked at by this liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Comparative Example 1>

Except having used 15.00 g of 12 mass % polyamic-acid solutions (D), it carried out similarly to Example 1, and obtained the liquid crystal aligning agent (4). Abnormality, such as muddiness and precipitation, was not looked at by this liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Comparative Example 2>

Except having used 15.00 g of 12 mass % polyamic-acid solutions (E), it carried out similarly to Example 1, and obtained the liquid crystal aligning agent (5). Abnormality, such as muddiness and precipitation, was not looked at by this liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Comparative Example 3>

Except having used 15.00 g of 12 mass % polyamic-acid solutions (F), it carried out similarly to Example 1, and obtained the liquid crystal aligning agent (6). Abnormality, such as muddiness and precipitation, was not looked at by this liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Comparative Example 4>

Except having used 15.00 g of 12 mass % polyamic-acid solutions (G), it carried out similarly to Example 1, and obtained the liquid crystal aligning agent (7). Abnormality, such as muddiness and precipitation, was not looked at by this liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

(Example 5)

After filtering the said liquid crystal aligning agent (1) with a 1.0 micrometer filter, it spin-coated to the 30 mm x 40 mm ITO board|substrate. After drying on an 80 degreeC hot plate for 2 minutes, it baked in a 230 degreeC hot-air circulation type oven for 14 minutes, and the coating film of 100 nm thickness was formed. The ultraviolet-ray of wavelength 254nm which the extinction ratio 26:1 linearly polarized was irradiated to this coating-film surface through the polarizing plate, and the liquid crystal aligning film was obtained.

The height of the anisotropy with respect to the orientation direction of the obtained liquid crystal aligning film was measured. The anisotropy value at 200 mJ/cm 2 of the irradiation amount of the ultraviolet ray was 3.39, the anisotropy value at 300 mJ/cm 2 was 4.10, and the anisotropy value at 400 mJ/cm 2 was 3.26. The irradiation amount of the ultraviolet rays at which the anisotropy becomes the highest was 300 mJ/cm 2 , which was set as the optimum irradiation condition in the photo-alignment treatment.

(Example 6)

Except having used the said liquid crystal aligning agent (2), it carried out similarly to Example 5, and obtained the liquid crystal aligning film. The magnitude|size of the anisotropy with respect to the orientation direction of the obtained liquid crystal aligning film was measured. The anisotropy value at 50 mJ/cm 2 of the irradiation amount of the ultraviolet rays was 0.05, the anisotropy value at 100 mJ/cm 2 was 0.61, and the anisotropy value at 200 mJ/cm 2 was 0.06. The irradiation amount of the ultraviolet ray at which the anisotropy was greatest was 100 mJ/cm 2 , which was the optimum irradiation condition in the photo-alignment treatment.

(Example 7)

Except having used the said liquid crystal aligning agent (3), it carried out similarly to Example 5, and obtained the liquid crystal aligning film. The magnitude|size of the anisotropy with respect to the orientation direction of the obtained liquid crystal aligning film was measured. The anisotropy value at 50 mJ/cm 2 of the irradiation amount of the ultraviolet rays was 0.10, the anisotropy value at 100 mJ/cm 2 was 0.92, and the anisotropy value at 200 mJ/cm 2 was 0.15. The irradiation amount of the ultraviolet ray at which the anisotropy was greatest was 100 mJ/cm 2 , which was the optimum irradiation condition in the photo-alignment treatment.

(Comparative Example 5)

Except having used the said liquid crystal aligning agent (4), it carried out similarly to Example 5, and obtained the liquid crystal aligning film. The magnitude|size of the anisotropy with respect to the orientation direction of the obtained liquid crystal aligning film was measured. The anisotropy value at 100 mJ/cm 2 of the irradiation amount of the ultraviolet rays was 3.02, the anisotropy value at 200 mJ/cm 2 was 5.37, and the anisotropy value at 300 mJ/cm 2 was 3.40. The irradiation amount of the ultraviolet rays at which the anisotropy becomes the greatest was 200 mJ/cm 2 , which was the optimum irradiation condition in the photo-alignment treatment.

(Comparative Example 6)

Except having used the said liquid crystal aligning agent (5), it carried out similarly to Example 5, and obtained the liquid crystal aligning film. The magnitude|size of the anisotropy with respect to the orientation direction of the obtained liquid crystal aligning film was measured. The anisotropy value at 200 mJ/cm 2 of the irradiation amount of the ultraviolet rays was 4.28, the anisotropy value at 300 mJ/cm 2 was 4.57, and the anisotropy value at 400 mJ/cm 2 was 3.03. The irradiation amount of the ultraviolet rays at which the anisotropy becomes the greatest was 300 mJ/cm 2 , which was set as the optimum irradiation condition in the photo-alignment treatment.

(Comparative Example 7)

Except having used the said liquid crystal aligning agent (6), it carried out similarly to Example 5 and obtained the liquid crystal aligning film. The magnitude|size of the anisotropy with respect to the orientation direction of the obtained liquid crystal aligning film was measured. The anisotropy value at 300 mJ/cm 2 of the irradiation amount of the ultraviolet rays was 0.54, the anisotropy value at 400 mJ/cm 2 was 0.65, and the anisotropy value at 500 mJ/cm 2 was 0.60. The irradiation amount of the ultraviolet ray with the greatest anisotropy was 400 mJ/cm 2 , which was the optimum irradiation condition in the photo-alignment treatment.

(Comparative Example 8)

Except having used the said liquid crystal aligning agent (7), it carried out similarly to Example 5, and obtained the liquid crystal aligning film. The magnitude|size of the anisotropy with respect to the orientation direction of the obtained liquid crystal aligning film was measured. The anisotropy value at 400 mJ/cm 2 of the irradiation amount of the ultraviolet ray was 1.61, the anisotropy value at 600 mJ/cm 2 was 1.71, and the anisotropy value at 800 mJ/cm 2 was 1.59. The irradiation amount of the ultraviolet ray at which the anisotropy was greatest was 600 mJ/cm 2 , which was the optimum irradiation condition in the photo-alignment treatment.

The result of having measured the magnitude|size of the anisotropy with respect to the orientation direction of the liquid crystal aligning film obtained by Examples 5-7 and Comparative Examples 5-8 is put together in Table 1, and is shown.

(Example 8)

After filtering the liquid crystal aligning agent (1) with a 1.0 μm filter, it was applied by spin coating to a glass substrate having a columnar spacer having a height of 4 μm and having an ITO film formed on the prepared substrate and the back surface of which the electrode was formed. After drying on an 80 degreeC hot plate for 5 minutes, it baked in a 230 degreeC hot air circulation type oven for 20 minutes, and the coating film of 100 nm thickness was formed. 0.3 J/cm<2> of ultraviolet rays with a wavelength of 254 nm linearly polarized at an extinction ratio of 26:1 were irradiated to this coating film surface through a polarizing plate. Then, it heated for 14 minutes on a 230 degreeC hot plate, and obtained the board|substrate with a liquid crystal aligning film. The above two substrates were set as one set, a sealant was printed on the substrate, and another substrate was attached so that the liquid crystal alignment film surface faced and the alignment direction was 0 °, and then the sealant was cured to prepare an empty cell. . Liquid crystal MLC-7026-100 (manufactured by Merck & Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS drive liquid crystal cell. Then, after heating the obtained liquid crystal cell at 110 degreeC for 1 hour, it was left to stand overnight and the residual image evaluation by long-term alternating-current drive was performed. The value of the angle Δ of this liquid crystal cell after long-term alternating current drive was 0.04 degrees. Further, as a result of observing the bright spots in the cell, the number of bright spots was less than 10, which was good.

(Example 9)

Except having used the said liquid crystal aligning agent (2), the coating film of 100 nm of film thickness was formed by the method similar to Example 8. After irradiating 0.1 J/cm<2> of ultraviolet rays of wavelength 254nm which linearly polarized at an extinction ratio of 26:1 through a polarizing plate to this coating film surface, it heated for 14 minutes on a 230 degreeC hot plate, and obtained the board|substrate with a liquid crystal aligning film. Except having used this board|substrate with a liquid crystal aligning film, the FFS drive liquid crystal cell was manufactured by the method similar to Example 8, and the residual image evaluation by long-term alternating-current drive was performed about the obtained cell. The value of angle Δ of this liquid crystal cell after long-term alternating current drive was 0.10 degree. Further, as a result of observing the bright spots in the cell, the number of bright spots was less than 10, which was good.

(Example 10)

After irradiation with polarized ultraviolet rays, an FFS drive liquid crystal cell was manufactured in the same manner as in Example 9, except that it was immersed in 2-propanol for 3 minutes and then immersed in pure water for 1 minute. About this FFS drive liquid crystal cell, afterimage evaluation by long-term AC drive was implemented. The value of angle Δ of this liquid crystal cell after long-term alternating current drive was 0.08 degrees. Further, as a result of observing the bright spots in the cell, the number of bright spots was less than 10, which was good.

(Example 11)

Except having used the said liquid crystal aligning agent (3), the coating film of 100 nm of film thickness was formed by the method similar to Example 8. After irradiating 0.1 J/cm<2> of ultraviolet-ray of wavelength 254nm linearly polarized with an extinction ratio of 26:1 through a polarizing plate to this coating film surface, it was immersed in 2-propanol for 3 minutes, and then immersed in pure water for 1 minute. Then, it heated for 14 minutes on a 230 degreeC hot plate, and obtained the board|substrate with a liquid crystal aligning film. Except having used this board|substrate with a liquid crystal aligning film, the FFS drive liquid crystal cell was manufactured by the method similar to Example 8, and the residual image evaluation by long-term alternating-current drive was performed about the obtained cell. The value of angle Δ of this liquid crystal cell after long-term alternating current drive was 0.08 degree. Further, as a result of observing the bright spots in the cell, the number of bright spots was less than 10, which was good.

(Comparative Example 9)

Except having used the said liquid crystal aligning agent (4), the coating film of 100 nm of film thickness was formed by the method similar to Example 8. 0.2 J/cm<2> of ultraviolet rays with a wavelength of 254 nm linearly polarized at an extinction ratio of 26:1 were irradiated to this coating film surface through a polarizing plate. Then, it heated for 14 minutes on a 230 degreeC hot plate, and obtained the board|substrate with a liquid crystal aligning film. Except having used this board|substrate with a liquid crystal aligning film, the FFS drive liquid crystal cell was manufactured by the method similar to Example 8, and the residual image evaluation by long-term alternating-current drive was performed about the obtained cell. The value of angle Δ of this liquid crystal cell after long-term alternating current drive was 0.15 degrees. In addition, as a result of observing the bright points in the cell, the number of bright points was 10 or more, which was defective.

(Comparative Example 10)

Except having used the said liquid crystal aligning agent (5), the coating film of 100 nm of film thickness was formed by the method similar to Example 8. 0.3 J/cm<2> of ultraviolet rays with a wavelength of 254 nm linearly polarized at an extinction ratio of 26:1 were irradiated to this coating film surface through a polarizing plate. Then, it heated for 14 minutes on a 230 degreeC hot plate, and obtained the board|substrate with a liquid crystal aligning film. Except having used this board|substrate with a liquid crystal aligning film, the FFS drive liquid crystal cell was manufactured by the method similar to Example 8, and the residual image evaluation by long-term alternating-current drive was performed about the obtained cell. The value of the angle Δ of this liquid crystal cell after a long-term alternating current drive was 0.20 degrees. In addition, as a result of observing the bright points in the cell, the number of bright points was 10 or more, which was defective.

(Comparative Example 11)

Except having used the said liquid crystal aligning agent (6), the coating film of 100 nm of film thickness was formed by the method similar to Example 8. 0.4 J/cm<2> of ultraviolet rays with a wavelength of 254 nm linearly polarized at an extinction ratio of 26:1 were irradiated to this coating film surface through a polarizing plate. Then, it heated for 14 minutes on a 230 degreeC hot plate, and obtained the board|substrate with a liquid crystal aligning film. Except having used this board|substrate with a liquid crystal aligning film, the FFS drive liquid crystal cell was manufactured by the method similar to Example 8, and the residual image evaluation by long-term alternating-current drive was performed about the obtained cell. The value of the angle Δ of this liquid crystal cell after a long-term alternating current drive was 0.20 degrees. In addition, as a result of observing the bright points in the cell, the number of bright points was 10 or more, which was defective.

(Comparative Example 12)

Except having used the said liquid crystal aligning agent (7), the coating film of 100 nm of film thickness was formed by the method similar to Example 8. 0.6 J/cm<2> of ultraviolet rays with a wavelength of 254 nm linearly polarized at an extinction ratio of 26:1 were irradiated to this coating film surface through a polarizing plate. Then, it heated for 14 minutes on a 230 degreeC hot plate, and obtained the board|substrate with a liquid crystal aligning film. Except having used this board|substrate with a liquid crystal aligning film, the FFS drive liquid crystal cell was manufactured by the method similar to Example 8, and the residual image evaluation by long-term alternating-current drive was performed about the obtained cell. The value of angle Δ of this liquid crystal cell after long-term alternating current drive was 0.24 degrees. In addition, as a result of observing the bright points in the cell, the number of bright points was 10 or more, which was defective.

The liquid crystal aligning film obtained from the liquid crystal aligning agent of the present invention has few bright points, which are factors for lowering the contrast, and can reduce afterimages caused by alternating current drive generated in a liquid crystal display element of an IPS drive system or an FFS drive system, and an afterimage characteristic A liquid crystal display element of this excellent IPS drive system or FFS drive system is obtained.

The liquid crystal display element having the liquid crystal alignment film of the present invention has excellent reliability and can be widely used in liquid crystal televisions, small and medium-sized car navigation systems, smartphones, etc. requiring a large screen, high resolution, and high display quality.

In addition, all the content of the JP Patent application 2014-219597, the claim, and the abstract for which it applied on October 28, 2014 is referred here, and it takes in as an indication of the specification of this invention.

Claims (11)

It has a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2) as a liquid crystal aligning agent for obtaining the liquid crystal aligning film for photo-alignment processing which can suppress generation|occurrence|production of a luminescent point also when negative liquid crystal is used The liquid crystal aligning agent characterized by containing at least 1 sort(s) of polymer (A) chosen from the group which consists of a polyimide precursor and the imidation polymer of this polyimide precursor.

(In formulas (1) and (2), X ₁ and X ₂ are each independently at least one selected from the group consisting of structures represented by the following formulas (X1-1) and (X1-2). R ₁ , R ₂ , R ₃ , R ₄ , and R ₆ are hydrogen atoms, R ₅ is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 3.)

According to claim 1,
The content ratio of the structural unit represented by the formula (1) is 10 to 50 mol% with respect to 1 mol of all structural units of the polymer (A), and the content ratio of the structural unit represented by the formula (2) is The liquid crystal aligning agent which is 20-90 mol% with respect to 1 mol of all structural units of the said polymer (A). According to claim 1,
The structural unit represented by formula (1) and the structural unit represented by formula (2) may exist in the same polyimide precursor, and the structural unit represented by formula (1) and the structural unit represented by formula (2) may be different The liquid crystal aligning agent which may exist in a polyimide precursor. According to claim 1,
In the formulas (1) and (2), X ₁ and X ₂ are the formulas (X1-2). delete According to claim 1,
The liquid crystal aligning agent in which 2-10 mass % of polymers (A) are contained. According to claim 1,
A liquid crystal aligning agent for optical alignment. The manufacturing method of the liquid crystal aligning film which irradiates the ultraviolet-ray which polarized to the film|membrane obtained by apply|coating and baking the liquid crystal aligning agent in any one of Claims 1-4, 6, and 7. According to claim 8,
The manufacturing method of the liquid crystal aligning film in which the polarized ultraviolet-ray has a wavelength of 100-800 nm. The liquid crystal display element which has a liquid crystal aligning film obtained by the method of Claim 8. According to claim 10,
A liquid crystal display element in which a liquid crystal contained in the liquid crystal display element is a negative liquid crystal material.