KR20190049909A - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

(X 는 O 또는 S, Y¹, Y² 는 단결합, -O-, -S-, -OCO-, 또는 COO-, R¹, R² 는 탄소수 1 ∼ 3 의 알킬렌기이다)Provided are a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display device having a high transmittance and rubbing resistance and capable of forming an improved liquid crystal alignment film in a wide temperature range with defective display.
A tetracarboxylic acid derivative obtained by reacting a diamine containing the diamine of the formula (1) in an amount of 20 mol% or more and 100 mol% or less with an aromatic tetracarboxylic acid derivative in an amount of 50 mol% or more and less than 100 mol% A polyimide precursor or a diamine containing 20 mol% or more and less than 100 mol% of a diamine represented by the formula (1) and a tetracarboxylic acid derivative containing an aromatic tetracarboxylic acid derivative in an amount of 50 mol% to 100 mol% A liquid crystal aligning agent containing a polyimide precursor obtained by reacting.

(X is O or S, Y ¹ and Y ² are a single bond, -O-, -S-, -OCO-, or COO-, and R ¹ and R ² are alkylene groups having 1 to 3 carbon atoms)

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal alignment film, a liquid crystal alignment film, a liquid crystal alignment film,

The present invention relates to a liquid crystal alignment agent (also referred to as a liquid crystal alignment treatment agent), a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film.

The liquid crystal alignment film is a film for controlling the alignment direction of the liquid crystal molecules to be constant in a liquid crystal display element or a phase difference plate using a polymerizable liquid crystal. The liquid crystal alignment film becomes a very important constituent member together with a liquid crystal or the like in a liquid crystal display element or the like.

In recent years, in the field of more advanced liquid crystal display devices, the liquid crystal alignment film is required to have heat resistance, solvent resistance, etc. in addition to the ability to control alignment of the liquid crystal (hereinafter also referred to as liquid crystal alignment property). In addition, various other characteristics are required for the liquid crystal display element to exhibit high performance.

One of the characteristics required for a liquid crystal alignment film is the improvement in display quality of a liquid crystal display element. For example, in a liquid crystal display element, improvement in display defects is required, and as a countermeasure against display defects, improvement of liquid crystal alignment film characteristics is required.

Particularly, in mobile phones and tablet-type terminals, which have recently been rapidly and precisely densified, a high display quality is required for liquid crystal display elements used. As a result, the specification for a so-called "afterimage phenomenon" or simply a display defect called "afterimage" is becoming more severe. For example, there is a demand for realizing a liquid crystal alignment film having a characteristic of rapidly disappearing even if a residual image is formed. In recent liquid crystal display devices, since the use environment does not stay indoors, high quality performance is required even at a high temperature such as in the outdoor or in the car, and a liquid crystal alignment film in which the afterimage characteristic does not change at room temperature and high temperature is required.

Further, in a mobile terminal such as a cellular phone, reduction in power consumption of a liquid crystal display element is required. In such a portable terminal, since the power consumption of the liquid crystal display element is reduced, the battery can be used for a long period of time by charging the battery once. In order to reduce the power consumption of the liquid crystal display element, the high transmittance of the liquid crystal display element is effective. Therefore, in a liquid crystal display element, it is required to improve transmittance of a constituent member such as a liquid crystal alignment film, in addition to a high aperture ratio of a pixel or the like.

In addition, the liquid crystal alignment film is required to have high resistance to rubbing treatment in view of applicability to a manufacturing process of a liquid crystal display device. The rubbing process is known as a method of forming a liquid crystal alignment film in a process of manufacturing a liquid crystal display device and is widely used industrially today. In the rubbing treatment, a polymer film such as polyimide is formed on a substrate, and the surface of the polymer film is rubbed with a cloth.

In the rubbing treatment, there is a problem that dust generated by cutting off the liquid crystal alignment film and scratches on the liquid crystal alignment film degrade the display quality. For this reason, the liquid crystal alignment film is required to be resistant to rubbing treatment (hereinafter also referred to as rubbing resistance).

As a method for forming a liquid crystal alignment film having a high rubbing resistance, a method of adding various additives to a polyimide constituting a liquid crystal alignment film or a polyimide precursor for forming the polyimide is known (see, for example, Patent Documents 1 and 2).

In addition, a polyimide structure having good rubbing resistance has been proposed (see, for example, Patent Documents 3 and 4).

By such a method, it is possible to prevent generation of scraping (also called rubbing shavings) and scratches (also called rubbing scratches) of the liquid crystal alignment film in the liquid crystal alignment film at the time of rubbing treatment.

However, in recent applications of liquid crystal display devices, there is a tendency that the polymer film such as polyimide is rubbed more strongly with a cloth in the rubbing treatment to perform the alignment treatment. This strong rubbing treatment is for the purpose of making the alignment state of the liquid crystal more uniform and stronger. For this reason, a higher level of rubbing resistance is required for the liquid crystal alignment film.

Japanese Patent Application Laid-Open No. 7-120769 Japanese Patent Application Laid-Open No. 9-146100 Japanese Patent Application Laid-Open No. 2008-90297 Japanese Patent Application Laid-Open No. 9-258229

An object of the present invention is to provide a liquid crystal aligning agent having a high liquid crystal aligning property and a rubbing resistance, which is effective for reducing a residual image in a wide temperature range in a liquid crystal display element and capable of forming a liquid crystal alignment film with high light transmittance.

It is another object of the present invention to provide a liquid crystal alignment film having a high liquid crystal aligning property and a rubbing resistance by using the liquid crystal aligning agent as described above and being effective for reducing afterimage in a wide temperature range in a liquid crystal display element, . Further, there is provided a liquid crystal display element having the liquid crystal alignment film.

The inventors of the present invention have made intensive studies to solve the above problems, and as a result, they have completed the present invention.

That is, the present invention has the following points.

(1) A liquid crystal aligning agent containing a polyimide precursor obtained by reacting a diamine component with a tetracarboxylic acid derivative,

Wherein the diamine component contains a diamine compound represented by the following formula (1) in an amount of 20 mol% to 100 mol%, and the tetracarboxylic acid derivative contains an aromatic tetracarboxylic acid derivative in an amount of 50 mol% Or the diamine component contains a diamine compound represented by the following formula (1) in a content of 20 mol% or more and less than 100 mol%, and the tetracarboxylic acid derivative contains an aromatic tetracarboxylic acid derivative in an amount of 50 mol% or more By mass or less and 100% by mole or less.

[Chemical Formula 1]

(1), X is an oxygen atom or a sulfur atom, Y ¹ and Y ² are independently a single bond, -O-, -S-, -OCO-, or COO-, and R ¹ and R ² are Independently, an alkylene group having 1 to 3 carbon atoms)

(2) The liquid crystal aligning agent according to (1), wherein the diamine component further contains a diamine compound represented by the following formula (AM1).

(2)

(In the formula (AM1), R ⁵ represents a divalent organic group having one structure selected from the group consisting of the following formulas (a-1) to (a-20), R ³ and R ⁴ independently A hydrogen atom or a monovalent organic group)

(3)

(3) a diamine compound represented by the formula (AM1) is, R ⁵ is of formula (a-1), formula (a-4), formula (a-5), formula (a-6), formula (a The liquid crystal aligning agent according to (2), wherein the liquid crystal aligning agent is a diamine compound having one structure selected from the group consisting of formulas (a-10), (a-16), (a-19) and

(4) The liquid crystal aligning agent according to any one of (1) to (3), wherein the diamine component contains the diamine compound represented by the formula (1) in an amount of 50 mol% or more and less than 100 mol%.

(5) The tetracarboxylic acid derivative is at least one compound selected from the group consisting of compounds represented by the following formulas (2-a) to (2-e) ≪ / RTI >

[Chemical Formula 4]

(In the formulas (2-a) to (2-e), R ⁷ represents an alkyl group and R ⁶ represents one structure selected from the group consisting of the following formulas (b-1) to ≪ / RTI >< RTI ID = 0.0 >

[Chemical Formula 5]

(6) The liquid crystal aligning agent according to (5), wherein the tetracarboxylic acid derivative is the formula (2-a).

(7) A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of (1) to (6) above.

(8) A liquid crystal display element having the liquid crystal alignment film according to (7) above.

The present invention can provide a liquid crystal aligning agent which has high liquid crystal alignment and rubbing resistance, is effective for reducing afterimage in a liquid crystal display element, and can form a liquid crystal alignment film with high light transmittance.

Further, the present invention can provide a liquid crystal alignment film having a high liquid crystal aligning property and a rubbing resistance, being effective for reducing afterimage in a liquid crystal display element, and having a high light transmittance by using the liquid crystal aligning agent.

In addition, the present invention can provide a liquid crystal display device using the liquid crystal alignment film having the above-mentioned characteristics.

The liquid crystal aligning agent of the present invention contains a polyimide precursor obtained by reacting a diamine component with a tetracarboxylic acid derivative. Polyimide precursors include polyamic acid, polyamic acid ester, and the like.

The polyimide precursor contained in the liquid crystal aligning agent of the present invention is formed using a tetracarboxylic acid derivative which is preferable for achieving desired properties by combining a diamine component having a characteristic structure with the diamine component.

Hereinafter, the diamine component and the tetracarboxylic acid derivative used for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention will be described in detail.

≪ Specific diamine compound (1) >

The liquid crystal aligning agent of the present invention uses a specific diamine compound having a specific structure represented by the following formula (1) as a diamine component for obtaining a polyimide precursor such as a polyamic acid or a polyamic acid ester.

[Chemical Formula 6]

(1), X is an oxygen atom or a sulfur atom, Y ¹ and Y ² are independently a single bond, -O-, -S-, -OCO-, or COO-, and R ¹ and R ² are And is independently an alkylene group having 1 to 3 carbon atoms.

When X in the formula (1) is an oxygen atom, the specific diamine compound of the formula (1) is a urea group-containing diamine compound. When X is a sulfur atom, thiourea (hereinafter, And the urea group may be collectively referred to as (thio) urea group).

Preferable examples of the diamine compound represented by the above formula (1) include the following compounds. Among them, compounds represented by formulas (1-1) and (1-5) to (1-8) are preferable.

(7)

The diamine component for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention contains the specific diamine compound of the formula (1) as an essential component, but the content of the specific diamine compound contained may be any value .

In order to obtain sufficient rubbing resistance of the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention, the specific diamine compound of the formula (1) in the total diamine component (100 mol%) is preferably 20 mol% or more, Is not less than 30 mol%, and more preferably not less than 50 mol%.

From the viewpoints of optimization of the pretilt angle of the liquid crystal and reduction of the accumulated charge when the polyimide is formed from the polyimide precursor contained in the liquid crystal aligning agent and applied to the liquid crystal display element as the liquid crystal alignment film, ) Is preferably less than 100 mol%, more preferably 30 to 60%, of the total diamine component.

When the content of the specific diamine compound represented by the formula (1) is 100 mol% in the total diamine component, that is, when all of the diamine components are the specific diamine compound represented by the formula (1), as described later, the polyimide precursor The content of the aromatic tetracarboxylic acid derivative in the tetracarboxylic acid derivative used for the formation of the tetracarboxylic acid derivative is from 50 mol% to less than 100 mol% of the total tetracarboxylic acid component. Therefore, in the liquid crystal aligning agent of the present invention, the diamine components are all the specific diamine compounds of the above formula (1), and the tetracarboxylic acid derivatives are not all aromatic tetracarboxylic acid derivatives.

≪ Diamine compound (AM1) >

The polyimide precursor contained in the liquid crystal aligning agent of the present invention is obtained by the reaction of a diamine component containing a specific diamine compound represented by the above formula (1) as an essential component and a tetracarboxylic acid derivative.

The diamine component for obtaining the polyimide precursor of the present invention can be obtained by reacting a diamine compound represented by the following formula (AM1) together with the specific diamine compound represented by the above formula (1) in combination with a tetracarboxylic acid derivative Is preferably used.

[Chemical Formula 8]

In the formula (AM1), R ⁵ represents a divalent organic group having one structure selected from the group consisting of the following formulas (a-1) to (a-20), and R ³ and R ⁴ independently represent A hydrogen atom or a monovalent organic group.

[Chemical Formula 9]

The diamine compound represented by the above formula (AM1) is preferably a compound represented by the following formula (1) in view of reducing the afterimage in the case where a polyimide is formed from a polyimide precursor contained in the liquid crystal aligning agent and then applied to a liquid crystal display element as a liquid crystal alignment film. ⁵ of the above formula (a-1), formula (a-4), formula (a-5), formula (a-6), formula (a-10), formula (a-16), formula (a- 19) and the formula (a-20). Particularly preferred is a diamine compound having one structure selected from the group consisting of (a-1), (A-4), (A-19) and (a-20).

The diamine component for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention may contain a diamine compound represented by the above formula (AM1) with the specific diamine compound of the above formula (1) as an essential component However, it is also possible to further contain other diamine compounds.

Namely, the diamine component for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention can be obtained by adding the specific diamine compound of the formula (1) and the diamine compound of the formula (AM1) It is also possible to contain other diamine compounds.

≪ Tetracarboxylic acid derivative >

The tetracarboxylic acid derivative usable for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention is not particularly limited.

Examples of the tetracarboxylic acid derivative of the present invention include tetracarboxylic acid dianhydride (represented by the following formula (2-a)), tetracarboxylic acid monoanhydride (represented by the following formula (2-b) (Represented by the following formula (2-d)), dicarboxylic acid dialkyl ester (represented by the following formula (2-c)), dicarboxylic acid chloride dialkyl ester And the like. The tetracarboxylic acid derivative is not limited to these as long as the reaction with the diamine proceeds.

The tetracarboxylic acid derivative preferably used in the present invention is at least one compound selected from the group consisting of the compounds represented by the following formulas (2-a) to (2-e).

Here, R ⁷ represents an alkyl group.

Specific examples of R ^{6 include} the following formulas [A-1] to [A-47].

[Chemical formula 10]

(11)

[Chemical Formula 12]

[Chemical Formula 13]

[Chemical Formula 14]

As the tetracarboxylic acid derivative that can be used for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention, the use of an aromatic tetracarboxylic acid derivative is particularly preferable. It is also possible to use all the tetracarboxylic acid derivatives as aromatic tetracarboxylic acid derivatives.

In order to obtain the polyimide precursor, it is possible to use two or more tetracarboxylic acid derivatives for the reaction with the diamine component. In this case, it is preferable to use at least one aromatic tetracarboxylic acid derivative in the tetracarboxylic acid derivative.

In addition, it is possible to use two or more aromatic tetracarboxylic acid derivatives having different tetracarboxylic acid derivatives as the aromatic tetracarboxylic acid derivatives and having different structures.

By containing an aromatic tetracarboxylic acid derivative as a tetracarboxylic acid derivative, it can be used for forming a polyimide precursor, and it becomes possible to improve the liquid crystal alignment property of the obtained liquid crystal alignment film. At this time, the content of the aromatic tetracarboxylic acid derivative relative to the total amount of the tetracarboxylic acid derivative to be used is preferably 50 mol% or more. However, when all of the diamine components used for forming the polyimide precursor are the diamine compounds represented by the above formula (1), as described above, the content of the aromatic tetracarboxylic acid derivative is preferably not less than the total amount of the tetracarboxylic acid derivative By weight based on 100% by mol.

Examples of the aromatic tetracarboxylic acid derivative which is preferably used for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention include compounds selected from the group consisting of the compounds represented by the above formulas (2-a) to (2-e) is at least one kind of compound, and R ⁷ is an alkyl group, an aromatic tetracarboxylic represents R ⁶ a to a formula (b-1) ~ formula (b-8) a tetravalent organic group having one structure selected from the group consisting of And a carboxylic acid derivative.

[Chemical Formula 15]

The formula (2-a) ~ formula (2-e) as shown, R ⁶ is an aromatic tetracarboxylic acid derivative having the structure shown by the formula (b-1), the specific example of the expression of the aforementioned R ⁶ [ A-26], which is a tetracarboxylic acid derivative.

Likewise, R ⁶ is an aromatic tetracarboxylic acid derivative having the structure shown by the formula (b-2) is, specific examples of R ⁶ is an example corresponding to the formula [A-27] a tetracarboxylic acid derivative.

R ⁶ is the structure of the aromatic tetracarboxylic acid derivative represented by the above formula (b-3), the specific examples of R ⁶ is an example for the tetracarboxylic acid derivative of the formula [A-28].

An aromatic tetracarboxylic acid derivative represented by the formula (b-4) of R ⁶ corresponds to a tetracarboxylic acid derivative in which the specific example of R ⁶ is the formula [A-29].

An aromatic tetracarboxylic acid derivative represented by the formula (b-5) of R ⁶ corresponds to a tetracarboxylic acid derivative in which the specific example of R ⁶ is the formula [A-31].

The aromatic tetracarboxylic acid derivative having a structure represented by the formula (b-6) in which R ⁶ corresponds to a tetracarboxylic acid derivative represented by the formula (A-30) is a specific example of R ⁶ .

The aromatic tetracarboxylic acid derivative having a structure represented by the formula (b-7) in which R ⁶ is represented by the formula (A-32) corresponds to the specific example of R ⁶ .

R ⁶ is an aromatic tetracarboxylic acid derivative having the structure shown by the formula (b-8) is, specific examples of R ⁶ is an example for the tetracarboxylic acid derivative of the formula [A-47].

Particularly preferred aromatic tetracarboxylic acid derivatives to be used for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention include the compounds represented by the formulas (2-a) to (2-e) R ⁷ is an alkyl group and R ⁶ is an aromatic tetracarboxylic acid derivative having a structure represented by the above formula (b-1), (b-2) or (b-7) .

<Polyimide precursor>

As a method for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention, a known method can be used.

A polyimide precursor is obtained by reacting a tetracarboxylic acid derivative containing an aromatic tetracarboxylic acid derivative with a diamine component containing the specific diamine compound of the formula (1) described above as an essential component.

The case where a tetracarboxylic acid dianhydride is used as the tetracarboxylic acid derivative will be described below as an example.

The polymerization reaction method of the diamine component and the tetracarboxylic acid derivative used in the production of the polyimide precursor contained in the liquid crystal aligning agent of the present invention is not particularly limited. And they are polymerized by mixing them in an organic solvent to obtain a polyamic acid which is a polyimide precursor. Polyamic acid esters can be obtained by esterifying a carboxylic acid group with polyamic acid using a known esterifying agent. The polyimide can be obtained by subjecting the obtained polyamic acid and polyamic acid ester to dehydration ring closure.

Examples of the method of mixing the diamine component and the tetracarboxylic acid derivative in an organic solvent include a method of directly adding a tetracarboxylic acid derivative component by stirring a solution in which a diamine component is dispersed or dissolved in an organic solvent, And a method in which the derivative component is dispersed or dissolved in an organic solvent and added.

Further, a method of adding a diamine component to a solution in which a tetracarboxylic acid derivative is dispersed or dissolved in an organic solvent, a method of alternately adding a tetracarboxylic acid derivative and a diamine, and the like can be given. When at least one of the tetracarboxylic acid derivative component and the diamine is composed of a plurality of compounds, the plural kinds of components may be polymerized in advance in a mixed state, or they may be subjected to polymerization reaction sequentially.

The temperature at which the diamine component and the tetracarboxylic acid derivative are polymerized in an organic solvent is usually 0 to 150 ° C, preferably 5 to 100 ° C, and more preferably 10 to 80 ° C. When the temperature is higher, the polymerization reaction is terminated quickly. However, when the temperature is too high, a polymer having a high molecular weight may not be obtained. The polymerization reaction can be carried out at an arbitrary injection concentration. However, if the injection concentration is too low, it becomes difficult to obtain a polymer having a high molecular weight. If the injection concentration is too high, the viscosity of the reaction liquid becomes too high, Preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The polymerization reaction may be carried out at a high concentration, and then an organic solvent may be added. The above-described injection concentration is the concentration of the total mass of the diamine component plus the tetracarboxylic acid derivative.

The organic solvent used in the above-mentioned polymerization reaction is not particularly limited as long as the resulting polyamic acid and polyamic acid ester (hereinafter sometimes referred to as polyamic acid (ester)) are dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetoamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexa Methyl sulfoxide, gamma -butyrolactone, and the like. These may be used alone or in combination. Further, even a solvent which does not dissolve the polyamic acid (ester) may be used in combination with the solvent insofar as the produced polyamic acid (ester) does not precipitate.

In addition, the water content in the organic solvent inhibits the polymerization reaction and further causes the hydrolysis of the produced polyamic acid (ester). Therefore, the organic solvent preferably is dehydrated and dried as much as possible.

The molar ratio of the tetracarboxylic acid derivative to the diamine used in the polymerization reaction to obtain the polyamic acid is preferably 1: 0.8 to 1: 1.2, and the closer the molar ratio is, the more the molecular weight of the obtained polyamic acid Lt; / RTI &gt; If the molecular weight of the polyamic acid (ester) is too small, the strength of the resulting coating film may be insufficient. Conversely, if the molecular weight of the polyamic acid (ester) is too large, the viscosity of the obtained liquid crystal aligning agent becomes excessively high, Workability and uniformity of the coating film may be deteriorated. Therefore, the weight average molecular weight of the polyamic acid (ester) used in the liquid crystal aligning agent of the present invention is preferably 2,000 to 500,000, more preferably 5,000 to 300,000.

The polyamic acid (ester) contained in the liquid crystal aligning agent of the present invention is obtained by the reaction of a diamine component and a tetracarboxylic acid derivative, but a specific diamine compound represented by the above formula (1) is used as an essential component do.

In addition to the specific diamine compound represented by the above formula (1), a diamine component containing a diamine compound represented by the above formula (AM1) or a diamine component containing a diamine compound other than these may be used as the diamine component do.

As the tetracarboxylic acid derivative, it is preferable to use a tetracarboxylic acid derivative containing the aromatic tetracarboxylic acid derivative described above.

The obtained polyamic acid can be represented by a repeating unit represented by the following formula (3).

The polyamic acid ester can be represented by the following formula (4).

[Chemical Formula 16]

In the formulas (3) and (4), R ^a , R ^b and R ^c independently represent a group derived from a diamine compound represented by the formula (1) or the formula (AM1).

When a specific diamine compound represented by the above formula (1) is used, R ^a and R ^b are hydrogen atoms and R ^c is -phenylene-Y ¹ -NH-CX-HN-R ² -Y ² -phenylene- . When a diamine compound represented by the above formula (AM1) is used, R ^a is R ³ , R ^b is R ⁴ , and R ^c is R ⁵ .

R ⁶ has the same meaning as R ⁶ in the tetracarboxylic acid derivative represented by the above formulas (2-a) to (2-e).

R in the formula (4) is a group derived from the esterifying agent used.

The polyamic acid or polyamic acid ester thus obtained can be used directly in the liquid crystal aligning agent of the present invention. The liquid crystal aligning agent of the present invention may also contain polyimide obtained by subjecting the polyamic acid or polyamic acid ester thus obtained to dehydration ring closure.

<Liquid Crystal Aligner>

The liquid crystal aligning agent of the present invention contains the polyimide precursor obtained as described above. Usually, the liquid crystal aligning agent may be a coating liquid obtained by dissolving these polymers in an organic solvent.

The liquid crystal aligning agent of the present invention may contain, in addition to the above-described polyimide precursor, a polyimide obtained from the polyimide precursor or a polymer having another structure.

The content of the polyimide precursor in the liquid crystal aligning agent of the present invention is preferably from 1 to 20 mass%, more preferably from 2 to 20 mass%, based on the total amount of the liquid crystal aligning agent.

The organic solvent contained in the liquid crystal aligning agent of the present invention is not particularly limited as long as it dissolves the polymer contained therein.

The amount of the organic solvent used is preferably 80 to 99% by mass, more preferably 80 to 98% by mass, based on the total amount of the liquid crystal aligning agent.

Specific examples of the organic solvent for use in the liquid crystal aligning agent of the present invention include N, N-dimethylformamide, N, N-dimethylacetoamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2 But are not limited to, pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, Diazolidinone, and the like. These may be used alone or in combination of two or more.

Further, even a solvent which does not dissolve the polymer such as polyimide precursor or polyimide alone can be mixed with the liquid crystal aligning agent of the present invention as far as the polymer does not precipitate.

Particularly, it is preferable to use ethylcellosolve, butylcellosolve, ethylcarbitol, butylcarbitol, ethylcarbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1- Propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol- A solvent having a low surface tension such as dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactic acid methyl ester, lactic acid ethyl ester, lactic acid N-propyl ester, lactic acid N-butyl ester, lactic acid Iso- , The coating film uniformity of the liquid crystal aligning agent to the substrate can be improved. When these solvents are used, they may be used alone or in combination.

In the liquid crystal aligning agent of the present invention, a solvent having a low surface tension is preferably used, but the amount of the solvent to be used is preferably 5 to 80 mass%, more preferably 20 to 80 mass% 60% by mass.

The liquid crystal aligning agent of the present invention may contain various additives in addition to the above-mentioned polyimide precursors, polymers such as polyimide and organic solvents, as long as they do not impair the effects of the present invention.

The liquid crystal aligning agent of the present invention can contain an additive which improves the film thickness uniformity and surface smoothness of the liquid crystal alignment film to be formed. Examples of such an additive include a fluorine-based surfactant, a silicon-based surfactant, and a nonionic surfactant.

(For example, EF Top EF301, EF303 and EF352 (manufactured by Tohchem Products)), Megapac F171, F173 and R-30 (manufactured by Dainippon Ink and Chemicals Inc.), Florado FC430 and FC431 SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Kagaku Co., Ltd.), and the like. The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

The liquid crystal aligning agent of the present invention can contain an additive that improves the adhesion between the liquid crystal alignment film to be formed and the substrate. Specific examples of such an additive include a functional silane-containing compound and an epoxy group-containing compound.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3 3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxy (2-aminoethyl) Aminopropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, Amine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl Acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N- Bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N- Aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neo Pentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6 Tetraglycidyl-2,4-hexanediol, N, N, N ', N', -tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylamino Methyl) cyclohexane, N, N, N ', N', -tetraglycidyl-4,4'-diaminodiphenylmethane and the like.

When these compounds are added, it is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, based on 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. If the amount is less than 0.1 part by mass, the effect of improving the adhesion can not be expected, and if it is more than 30 parts by mass, the liquid crystal alignment property of the formed liquid crystal alignment film may be lowered.

The liquid crystal aligning agent of the present invention may contain, in addition to the above-mentioned additives, a dielectric substance other than the polymer or a dielectric substance or a conductive substance for changing the electric characteristics such as the dielectric constant or conductivity of the liquid crystal orientation film, , And further, a crosslinkable compound for the purpose of increasing the hardness and density of the film when it is used as a liquid crystal alignment film can be added.

The concentration of the solid content in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the film thickness of the intended liquid crystal alignment film. The concentration of the polymer is preferably from 1 to 20% by mass, more preferably from 2 to 10% by mass, so that a coating film free from defects can be formed and an appropriate film thickness can be obtained as a liquid crystal alignment film.

In the liquid crystal aligning agent of the present invention, a soluble polyimide, polyamic acid, polyamic acid ester, or the like having different molecular structures together with the above-described polyimide precursor may be blended and contained. In this case, considering the fact that the obtained polyimide film has desired characteristics, the total amount of the polyimide precursor of the present invention described above combined with the soluble polyimide, polyamic acid, polyamic acid ester, Mol%) is preferably 5 to 95 mol%, more preferably 10 to 90 mol%.

The liquid crystal aligning agent of the present invention can be used as a liquid crystal alignment film by applying it on a substrate to form a coating film and then subjecting it to firing followed by rubbing treatment or light irradiation or in the case of vertical orientation, And can be used as an alignment film.

The substrate to be used is not particularly limited as long as it is a substrate having high transparency. For example, a plastic substrate such as a glass substrate, an acrylic substrate, or a polycarbonate substrate can be used, and it is preferable to use a substrate on which an ITO (Indium Tin Oxide) electrode for liquid crystal driving is formed from the viewpoint of simplifying the process . When a reflective liquid crystal display element is constituted, an opaque material such as a silicon wafer can be used for only one substrate. As the electrode in this case, a material that reflects light such as aluminum may be used.

The coating method of the liquid crystal aligning agent is not particularly limited, but industrially applicable methods such as screen printing, offset printing, flexographic printing, and inkjet coating. As another coating method, there is a coating method using a dip, a roll coater, a slit coater, a spinner or the like, and they can be used depending on the purpose.

The baking of the substrate coated with the liquid crystal aligning agent can be carried out at an arbitrary temperature of 100 to 350 ° C, preferably 150 to 300 ° C, and more preferably 180 to 250 ° C.

When polyamic acid or polyamic acid ester is contained in the liquid crystal aligning agent, the conversion rate to the polyimide is changed according to the sintering temperature, but the liquid crystal aligning agent of the present invention does not necessarily need to be imidized at 100%.

Further, the baking time of the coating film of the liquid crystal aligning agent can be set to any time. When the baking time is too short, the display defects may occur due to the influence of the residual solvent, so that the baking time is preferably 5 to 60 minutes, and more preferably 10 to 40 minutes.

When the thickness of the coated film after firing is too large, the power consumption of the liquid crystal display element becomes disadvantageous. When the thickness is too thin, the reliability of the liquid crystal display element may be deteriorated. Therefore, the thickness of the coating film is preferably 5 to 300 nm, more preferably 10 to 100 nm.

When the liquid crystal is horizontally oriented or tilted, it is preferable to subject the coated film after firing to orientation treatment by rubbing, polarized ultraviolet irradiation, or the like.

<Liquid crystal display element>

The liquid crystal display element of the present invention can be obtained by preparing a substrate having a liquid crystal alignment film adhered thereto from the liquid crystal aligning agent of the present invention by the above method using a substrate having an electrode attached thereto and then manufacturing a liquid crystal cell by a known method, It can be configured as a liquid crystal display element.

The manufacturing method of the liquid crystal cell can be, for example, as follows.

A pair of substrates on which an electrode for driving the liquid crystal is formed on at least one side are prepared. A liquid crystal alignment film of the present invention is formed on the pair of substrates, and a pair of substrates on which a liquid crystal alignment film is formed are prepared. Next, the spacers are dispersed on the liquid crystal alignment film of the substrate of the single chamber to make the liquid crystal alignment film surface inward, and the substrates of the other single chamber are bonded to each other, and the liquid crystal is injected under reduced pressure and sealed. Thus, a liquid crystal display element is manufactured.

After preparing a pair of substrates having the liquid crystal alignment film of the present invention, liquid crystal is dropped on the liquid crystal alignment film surface on which the spacer is dispersed, and then the substrates are bonded and sealed to produce a liquid crystal display device. In these cases, the thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

As described above, the liquid crystal display element of the present invention, which is manufactured using the liquid crystal aligning agent of the present invention, is excellent in reliability as well as high luminance with reduced afterimage phenomenon and excellent display quality. Therefore, it can be suitably used for display devices such as high-definition liquid crystal televisions and smart phones and tablet-type devices in a large screen.

Example

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

Abbreviations used in Examples and Comparative Examples are as follows.

DA-1: 1,3-bis (4-aminophenetyl) urea

DA-2: Para-phenylenediamine

DA-3: 1,5-bis (4-aminophenoxy) pentane

DA-4: N-methyl 4-aminophenethylamine

DA-5: 4,4'-diaminodiphenylmethane

DA-6: 4,4'-diaminodiphenylamine

DA-7: 1,3-bis (4-aminophenoxy) benzene

CA-1: pyromellitic acid dianhydride

CA-2: 1,2,3,4-Cyclobutane tetracarboxylic acid dianhydride

CA-3: 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride

CA-4: 3,4-Dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride

CA-5: 2,5-dicarbomethoxyterephthalic acid

CA-6: 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride

[Example 1]

8.96 g (30.0 mmol) of DA-1 and 3.24 g (30.0 mmol) of DA-2 were placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 141 g was added and dissolved by stirring while nitrogen was being supplied. Subsequently, 12.82 g (58.7 mmol) of CA-1 was added while stirring the diamine solution, N-methyl-2-pyrrolidone was further added so as to have a solid content concentration of 12 mass% At room temperature for 20 hours to obtain a solution of polyamic acid (P1). The viscosity of this polyamic acid (P1) solution at 25 캜 was confirmed to be 297 mPa s by an E-type viscometer (manufactured by Toki Industry Co., Ltd.).

To 50.30 g of this polyamic acid (P1) solution were added 23.37 g of N-methyl-2-pyrrolidone, 5.83 g of a N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and And 26.49 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a concentration of P1 of 5.5 mass%.

Table 1 summarizes the amount (mol) of each tetracarboxylic acid derivative component and the amount (mol) of each diamine component used in the synthesis of polyamic acid A1. Similarly, in Table 1, the amounts (moles) of the respective tetracarboxylic acid derivative components used in the synthesis of the polyamic acids (P2 to P8 and A1 to A6) in Examples 2 to 8 and Comparative Examples 1 to 6, And the amount (mole) of each diamine component are also shown in the table.

Table 2 shows A7 which is a mixed solution of polyamic acid.

(Evaluation of rubbing resistance)

The obtained liquid crystal aligning agent was filtered with a filter of 1.0 占 퐉 and then spin-coated on a glass substrate with a transparent electrode attached thereto. The resultant was dried on a hot plate at 50 占 폚 for 5 minutes and then baked at 230 占 폚 for 30 minutes, Of a polyimide film was obtained. This polyimide film was rubbed with a rayon cloth (roll diameter 120 mm, rotation speed 1000 rpm, moving speed 30 mm / sec and indentation amount 0.4 mm). The surface state of the film surface was observed using a confocal laser microscope (manufactured by Laser Tech Co., Ltd.), and the presence or absence of residue scraped with a magnification of 10 times and the size thereof were observed. When the film scraping due to rubbing is large, or when film scraping having a size of 30 mu m or more has occurred, it is judged as &quot; defective &quot;. In the case where no such phenomenon occurred, it was judged that the rubbing resistance was "good". The evaluation results are shown in Table 3.

(Transmittance measurement (luminous transmittance (Y value (%)))

After filtering the resultant liquid crystal aligning agent with a filter of 1.0 mu m, the alignment agent was spin-coated on the quartz substrate, dried on a hot plate at 50 DEG C for 5 minutes, and then baked at 230 DEG C for 30 minutes to obtain a Thereby forming a polyimide film. On both sides of the coated film surface of this substrate, a double-faced tape was stuck to only two sides, and nothing was bonded to a quartz substrate on which no film was formed. Liquid paraffin was injected into the obtained simplified cell and the transmittance was measured using UV-3100PC manufactured by Shimadzu Corporation. The luminous transmittance was calculated from the obtained data. The luminous transmittance was evaluated as "good" when the value was 96% or more, and "poor" when the luminous transmittance was less than 96%. The evaluation results are shown in Table 3. The luminous transmittance was calculated by using commercially available software (color measurement software: P / N206-65207, manufactured by Shimadzu Corporation).

(Production of liquid crystal cell)

Thereby manufacturing a liquid crystal cell having a configuration of an IPS (In-Planes Switching) mode liquid crystal display element.

First, a substrate with an electrode attached thereto 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, an ITO electrode having a pattern formed as a whole constituting the counter electrode as the first layer is formed. On the first layer counter electrode, a SiN (silicon nitride) film formed by a CVD method is formed as a second layer. The thickness of the second-layer SiN film is 500 nm and functions as an interlayer insulating film. On the second-layer SiN film, pixel electrodes on the combs formed by patterning the ITO film as the third layer are disposed, and two pixels, i.e., the first pixel and the second pixel, are formed. The size of each pixel is 10 mm in length and 5 mm in width. At this time, the first layer counter electrode and the third layer pixel electrode are electrically insulated by the action of the second layer SiN film.

The third layer pixel electrode has a comb-like shape formed by arranging a plurality of elongated electrode elements bent at the center portion. The width of each electrode element in the width direction is 3 占 퐉, and the interval between the electrode elements is 6 占 퐉. Since the pixel electrode forming each pixel is constituted by arranging a plurality of elongated electrode elements bent at the center portion, the shape of each pixel is not a rectangular shape but a shape of a bold line Like shape. Further, each pixel has a first region on the upper side of the bent portion and a second region on the lower side, which are divided into upper and lower portions with the central bent portion as a boundary.

When the first region and the second region of each pixel are compared with each other, the electrode elements of the pixel electrodes constituting the first region and the second region are formed in different directions. In other words, when the rubbing direction of the liquid crystal alignment layer, which will be described below, is taken as a reference, the electrode elements of the pixel electrodes are formed so as to form an angle of +10 degrees (clockwise) in the first region of the pixel, The element is formed so as to form an angle (clockwise direction) of -10 degrees. That is, in the first region and the second region of each pixel, the directions of rotation (inflation / switching) of the liquid crystal caused by the application of the voltage between the pixel electrode and the counter electrode are opposite to each other .

Next, the obtained liquid crystal aligning agent was filtered with a filter of 1.0 mu m, and then spin-coated on each of the prepared substrate having the electrode and the glass substrate having the ITO film formed thereon. Subsequently, the film was dried on a hot plate at 50 DEG C for 5 minutes, and then baked at 230 DEG C for 30 minutes to obtain a polyimide film on each substrate as a film having a film thickness of 70 nm. This polyimide film was subjected to rubbing (roll diameter 120 mm, rotation speed 500 rpm, moving speed 30 mm / sec and press-in amount 0.3 mm) by rayon cloth in a predetermined rubbing direction, and then ultrasonic irradiation was performed for 1 minute in pure water And dried at 80 DEG C for 10 minutes.

Thereafter, 4 mu m of a bead spacer (manufactured by NIKKYU CHEMICAL Co., Ltd.) was dispersed only on the substrate of the single chamber. Using the two kinds of substrates with the liquid crystal alignment films thus treated, the rubbing directions were combined so as to be anti-parallel, and the periphery was sealed while leaving the liquid crystal injection ports, thereby producing empty cells with a cell gap of 3.6 탆. Liquid crystal (MLC-2041, manufactured by Merck) was vacuum-injected into the empty cell at room temperature, and then the injection port was sealed to obtain an anti-parallel alignment liquid crystal cell. The resulting liquid crystal cell constitutes an IPS mode liquid crystal display element. Thereafter, the obtained liquid crystal cell was heated at 110 DEG C for 1 hour, left standing overnight, and used for evaluation.

(Residual image recovery time evaluation (residual image evaluation))

The following images were used to evaluate the afterimage.

The prepared liquid crystal cell was placed between two polarizers arranged so that the polarization axis thereof was orthogonal to each other. The LED backlight was turned on in a voltage unapplied state, and the arrangement angle of the liquid crystal cell was adjusted so that the luminance of transmitted light was minimized.

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

In the residual image evaluation, an AC voltage of 30 Hz with a relative transmittance of 23% was applied, and a DC voltage of 2 V was applied at the same time while driving the liquid crystal cell, and the device was driven for 120 minutes. Thereafter, the applied direct current voltage value was set to 0 V, and only the application of the direct current voltage was stopped, and the device was further driven for 60 minutes in this state.

The residual image evaluation was evaluated as &quot; good &quot; when the relative transmittance was recovered to not more than 25% until 60 minutes elapsed after the application of the DC voltage was stopped. When the relative transmittance was required to be recovered to 25% or less for 60 minutes or longer, it was evaluated as &quot; defective &quot;.

The after-image evaluation according to the above-described method was performed under two kinds of temperature conditions, that is, a temperature of the liquid crystal cell was 23 ° C and a temperature of 60 ° C. The evaluation results are shown in Table 3.

(Long-term drive evaluation (residual image evaluation))

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

Using this liquid crystal cell, an AC voltage of 8 V _PP was applied for 100 hours at a frequency of 30 Hz under a constant temperature environment of 60 占 폚. Thereafter, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited, and left at room temperature for one day.

After leaving the liquid crystal cell, the liquid crystal cell was placed on two polarizing plates arranged so that the polarization axis thereof was orthogonal to each other. The backlight was turned on in a voltage unapplied state and the arrangement angle of the liquid crystal cell was adjusted so that the luminance of transmitted light was minimized. Further, the rotation angle at which the liquid crystal cell was rotated from the angle at which the second area of the first pixel was darkest to the angle at which the first area became darkest was calculated as the angle?. Similarly, in the second pixel, the second region is compared with the first region, and the same angle? Is calculated. And the average value of the angles? Of the first and second pixels was calculated as the angle? Of the liquid crystal cell. When the value of the angle &amp;thetas; of the liquid crystal cell exceeds 0.2 degrees, it is defined as &quot; defective &quot; When the value of the angle? Of the liquid crystal cell did not exceed 0.2 degrees, it was evaluated as &quot; good &quot;. The evaluation results are shown in Table 3.

[Example 2]

7.46 g (25.0 mmol) of DA-1 and 7.15 g (25.0 mmol) of DA-3 were placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen introducing tube, and N-methyl- 143.3 g was added and dissolved by stirring while nitrogen was being supplied. While stirring the diamine solution, 10.26 g (47.0 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added so as to have a solid content concentration of 12 mass% The mixture was stirred for 20 hours to obtain a solution of polyamic acid (P2). The viscosity of this polyamic acid (P2) solution at 25 占 폚 was determined by an E-type viscometer (manufactured by Toki Industries Co., Ltd.) and found to be 305 mPa 占 퐏.

To 50.40 g of this polyamic acid (P2) solution were added 22.07 g of N-methyl-2-pyrrolidone, 5.74 g of N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and And 26.07 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a concentration of P2 of 5.5 mass%.

[Example 3]

4.47 g (15.0 mmol) of DA-1 and 1.62 g (15.0 mmol) of DA-2 were placed in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 62.9 g was added and dissolved by stirring while nitrogen was being supplied. While stirring the diamine solution, 1.59 g (6.0 mmol) of CA-3 and 9.0 g of N-methyl-2-pyrrolidone were added and stirred while nitrogen was being supplied. After stirring for 3 hours, 5.04 g (23.1 mmol) of CA-1 was added, N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12 mass% Followed by stirring to obtain a solution of polyamic acid (P3). The viscosity of this polyamic acid (P3) solution at 25 占 폚 was determined by an E-type viscometer (manufactured by Toki Industries Co., Ltd.) and found to be 280 mPa 占 퐏.

To 83.48 g of the polyamic acid (P3) solution were added 26.92 g of N-methyl-2-pyrrolidone, 9.60 g of a N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3- aminopropyltriethoxysilane and 40.0 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a P3 concentration of 6.0% by mass.

[Example 4]

4.83 g (16.2 mmol) of DA-1 and 1.17 g (10.8 mmol) of DA-2 were placed in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 62.4 g was added and dissolved by stirring while nitrogen was being fed. While stirring the diamine solution, 2.85 g (10.8 mmol) of CA-3 and 8.9 g of N-methyl-2-pyrrolidone were added and stirred while nitrogen was supplied. After stirring for 3 hours, 3.30 g (15.1 mmol) of CA-1 was added, N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12 mass% Followed by stirring to obtain a solution of polyamic acid (P4). The viscosity of this polyamic acid (P4) solution at 25 캜 was confirmed to be 288 mPa s by an E-type viscometer (manufactured by Toki Industry Co., Ltd.).

To 82.76 g of the polyamic acid (P4) solution, 27.64 g of N-methyl-2-pyrrolidone, 9.60 g of a N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and 40.0 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a P4 concentration of 6.0% by mass.

[Example 5]

1.34 g (12.4 mmol) of DA-1 and 3.55 g (12.4 mmol) of DA-3 were added to a 100 ml four-necked flask equipped with a stirrer and a nitrogen- ), 64.7 g of N-methyl-2-pyrrolidone was added, and dissolved with stirring while nitrogen was being supplied. While stirring the diamine solution, 2.43 g (12.4 mmol) of CA-2 and 9.5 g of N-methyl-2-pyrrolidone were added and stirred while nitrogen was supplied. After stirring for 1 hour, 3.58 g (16.4 mmol) of CA-1 was added and N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12 mass% Followed by stirring to obtain a solution of polyamic acid (P5). The viscosity of this polyamic acid (P5) solution at 25 占 폚 was confirmed by an E-type viscometer (manufactured by Toki Industries Co., Ltd.), and found to be 264 mPa 占 퐏.

To 84.21 g of this polyamic acid (P5) solution were added 26.19 g of N-methyl-2-pyrrolidone, 9.60 g of a N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and 40.0 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a P5 concentration of 6.0% by mass.

[Example 6]

4.62 g (15.5 mmol) of DA-1 and 1.68 g (15.5 mmol) of DA-2 were placed in a 100-mL four-necked flask equipped with a stirrer and a nitrogen inlet tube and N-methyl-2-pyrrolidone 62.9 g was added and dissolved by stirring while nitrogen was being supplied. While stirring the diamine solution, 1.22 g (6.2 mmol) of CA-2 and 8.7 g of N-methyl-2-pyrrolidone were added and stirred while nitrogen was supplied. After stirring for 1 hour, 5.04 g (23.1 mmol) of CA-1 was added, N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12% by mass, Followed by stirring to obtain a solution of polyamic acid (P6). The viscosity of this polyamic acid (P6) solution at 25 占 폚 was confirmed by an E-type viscometer (manufactured by Toki Industries Co., Ltd.) and found to be 262 mPa 占 퐏.

To 84.96 g of this polyamic acid (P6) solution were added 25.44 g of N-methyl-2-pyrrolidone, 9.60 g of an N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and 40.0 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a P6 concentration of 6.0 mass%.

[Example 7]

10.39 g (34.8 mmol) of DA-1 and 2.51 g (23.2 mmol) of DA-2 were placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 142.9 g was added and dissolved by stirring while nitrogen was supplied. While stirring the diamine solution, 3.87 g (19.7 mmol) of CA-2 and 35.0 g of N-methyl-2-pyrrolidone were added and stirred while nitrogen was supplied. After stirring for 2 hours, 7.82 g (35.9 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12 mass% Followed by stirring to obtain a solution of polyamic acid (P7). The viscosity of this polyamic acid (P7) solution at 25 캜 was confirmed to be 328 mPa s by an E-type viscometer (manufactured by Toki Industries Co., Ltd.).

To 105.08 g of this polyamic acid (P7) solution were added 42.93 g of N-methyl-2-pyrrolidone, 12.0 g of an N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane, 40.0 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a P7 concentration of 6.0% by mass.

[Example 8]

4.18 g (14.0 mmol) of DA-1 and 2.10 g (14.0 mmol) of DA-4 were placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 70.5 g was added and dissolved by stirring while nitrogen was being supplied. 5.86 g (26.9 mmol) of CA-1 was added while stirring the diamine solution, N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12 mass% And stirred for a time to obtain a solution of polyamic acid (P8). The viscosity of this polyamic acid (P8) solution at 25 캜 was confirmed to be 311 mPa s by an E-type viscometer (manufactured by Toki Industry Co., Ltd.).

To 55.74 g of this polyamic acid (P8) solution were added 15.61 g of N-methyl-2-pyrrolidone, 6.2 g of a solution of N-methyl-2-pyrrolidone containing 1.0% by mass of 3-aminopropyltriethoxysilane, 25.85 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a P8 concentration of 6.0 mass%.

[Example 9]

7.94 g (28.1 mmol) of CA-5 and 136.5 g of N-methyl-2-pyrrolidone were placed in a 200-ml four-necked flask equipped with a stirrer and a nitrogen-introducing tube and completely dissolved. Next, 6.16 g of triethylamine was added, and 4.33 g (14.5 mmol) of DA-1 and 2.18 g (14.5 mmol) of DA-4 were added and completely dissolved. Thereafter, the reaction solution was cooled and 23.35 g (60.9 mmol) of diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate was added while stirring with a magnetic stirrer , And further, 18.75 g of N-methyl-2-pyrrolidone was added, and stirring was continued for 5 hours. Thereafter, the reaction solution was poured little by little into isopropyl alcohol having a mass of 6 times the mass of the reaction solution, and stirring was continued for 1 hour. Thereafter, the precipitate obtained by filtration was stirred for one hour with isopropyl alcohol having a mass of 2 times, and filtered again to recover the precipitate. Thereafter, this operation was repeated twice, and the resulting precipitate was dried at 100 ° C under reduced pressure for 24 hours to obtain 10.54 g of polyamic acid ester (P9). 5.14 g of the resulting solid was completely dissolved with 37.69 g of N-methyl-2-pyrrolidone. Next, 38.55 g of N-methyl-2-pyrrolidone and 20.10 g of butyl cellosolve were added to the solution to obtain a liquid crystal aligning agent having a P9 concentration of 4.5% by mass.

[Example 10]

1.50 g (5.03 mmol) of DA-1 and 5.85 g (20.0 mmol) of DA-7 were placed in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 73 g was added and dissolved by stirring while nitrogen was being supplied. While this diamine solution was being stirred, 5.23 g (24.0 mmol) of CA-1 was added, N-methyl-2-pyrrolidone was further added so that the solid content concentration became 12 mass% Followed by stirring for 20 hours to obtain a solution of polyamic acid (P10). The viscosity of the polyamic acid solution at 25 캜 was confirmed to be 327 mPa s by an E-type viscometer (manufactured by Toki Industries Co., Ltd.).

15.49 g of N-methyl-2-pyrrolidone and 16.86 g of butyl cellosolve were added to 35.10 g of this polyamic acid solution to obtain a liquid crystal aligning agent having a P10 concentration of 6.0% by mass.

[Example 11]

3.73 g (12.5 mmol) of DA-1 and 3.65 g (12.5 mmol) of DA-7 were placed in a 100-mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 73 g was added and dissolved by stirring while nitrogen was being supplied. While stirring the diamine solution, 5.18 g (23.8 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added thereto so that the solid content concentration became 12 mass% Followed by stirring for 20 hours to obtain a solution of polyamic acid (P11). The viscosity of this polyamic acid solution at 25 캜 was confirmed to be 289 mPa s by an E-type viscometer (manufactured by Toki Industries Co., Ltd.).

10.74 g of N-methyl-2-pyrrolidone and 8.00 g of butyl cellosolve were added to 11.92 g of the polyamic acid solution to obtain a liquid crystal aligning agent having a P11 concentration of 4.5% by mass.

[Example 12]

2.21 g (7.41 mmol) of DA-1 and 5.01 g (17.1 mmol) of DA-7 were placed in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 73 g was added and dissolved by stirring while nitrogen was being supplied. While stirring the diamine solution, 5.07 g (23.2 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added so as to have a solid content concentration of 12 mass% Followed by stirring for 20 hours to obtain a solution of polyamic acid (P12). The viscosity of this polyamic acid solution at 25 캜 was confirmed to be 267 mPa s by an E-type viscometer (manufactured by Toki Industry Co., Ltd.).

20.62 g of N-methyl-2-pyrrolidone and 23.49 g of butyl cellosolve were added to 49.84 g of the polyamic acid solution to obtain a liquid crystal aligning agent having a P12 concentration of 6.0% by mass.

[Example 13]

1.43 g (4.80 mmol) of DA-1 and 5.61 g (19.2 mmol) of DA-7 were placed in a 100-mL four-necked flask equipped with a stirrer and a nitrogen inlet tube and N-methyl-2-pyrrolidone 79 g were added and dissolved by stirring while nitrogen was being supplied. While stirring the diamine solution, 6.77 g (23.0 mmol) of CA-6 was added, N-methyl-2-pyrrolidone was further added so that the solid content concentration became 12 mass% At room temperature for 20 hours to obtain a solution of polyamic acid (P13). The viscosity of this polyamic acid solution at 25 占 폚 was determined by an E-type viscometer (manufactured by Toki Industries Co., Ltd.) and found to be 240 mPa 占 퐏.

7.22 g of N-methyl-2-pyrrolidone and 7.32 g of butyl cellosolve were added to 14.76 g of the polyamic acid solution to obtain a liquid crystal aligning agent having a P13 concentration of 6.0% by mass.

[Comparative Example 1]

17.75 g (62.0 mmol) of DA-3 was placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 139.1 g of N-methyl-2-pyrrolidone was added, . 12.91 g (59.2 mmol) of CA-1 was added while stirring the diamine solution under cooling with water, N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12 mass% And the mixture was stirred for 20 hours while heating at 0 to obtain a solution of polyamic acid (A1). The viscosity of this polyamic acid (A1) solution at 25 캜 was 530 mPa 확인 as a result of an E-type viscometer (manufactured by Toki Industries Co., Ltd.).

To 50.00 g of the polyamic acid (A1) solution were added 43.95 g of N-methyl-2-pyrrolidone, 5.6 g of a N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and 24.89 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a concentration of Al of 4.5% by mass.

[Comparative Example 2]

3.25 g (30.0 mmol) of DA-2 and 8.60 g (30.0 mmol) of DA-3 were placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen-introducing tube and N-methyl-2-pyrrolidone 138.1 g was added, and dissolved by stirring while nitrogen was supplied. 12.59 g (57.7 mmol) of CA-1 was added while the diamine solution was stirred under cooling with water. N-methyl-2-pyrrolidone was further added thereto so as to have a solid content concentration of 12 mass% And stirred for a time to obtain a solution of polyamic acid (A2). The viscosity of this polyamic acid (A2) solution at 25 占 폚 was determined by an E-type viscometer (manufactured by Toki Industries Co., Ltd.) and found to be 310 mPa 占 퐏.

To 52.34 g of this polyamic acid (A2) solution were added 23.18 g of N-methyl-2-pyrrolidone, 5.98 g of an N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and 27.17 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a concentration of A2 of 5.5% by mass.

[Comparative Example 3]

7.64 g (25.6 mmol) of DA-1 and 4.15 g (38.4 mmol) of DA-2 were placed in a 200-ml four-necked flask equipped with a stirrer and a nitrogen inlet tube and N-methyl-2-pyrrolidone 141.6 g was added and dissolved by stirring while nitrogen was being supplied. While stirring the diamine solution under water-cooling, 6.81 g (34.7 mmol) of CA-2 and 35.4 g of N-methyl-2-pyrrolidone were added and stirred while nitrogen was supplied. After stirring for 2 hours, 5.58 g (25.6 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added so that the solid content concentration became 12 mass%, and the mixture was stirred for 20 hours under a nitrogen atmosphere To obtain a solution of polyamic acid (A3). The viscosity of this polyamic acid (A3) solution at 25 캜 was 276 mPa 확인 as determined by an E-type viscometer (manufactured by Toki Industry Co., Ltd.).

To 53.33 g of this polyamic acid (A3) solution were added 22.01 g of N-methyl-2-pyrrolidone, 6.12 g of an N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane, 20.35 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a concentration of A3 of 6.0 mass%.

[Comparative Example 4]

3.14 g (10.5 mmol) of DA-1 and 2.64 g (24.4 mmol) of DA-2 were placed in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 71.6 g was added and dissolved by stirring while nitrogen was being supplied. While this diamine solution was stirred under cooling with water, 6.55 g (33.4 mmol) of CA-2 was added, N-methyl-2-pyrrolidone was further added so as to have a solid content concentration of 12 mass% , And stirred for 20 hours to obtain a solution of polyamic acid (A4). The viscosity of this polyamic acid (A4) solution at 25 占 폚 was determined by an E-type viscometer (manufactured by Toki Industries Co., Ltd.) and found to be 274 mPa 占 퐏.

8.64 g of N-methyl-2-pyrrolidone, 2.32 g of an N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane, 7.76 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a concentration of A4 of 6.0% by mass.

[Comparative Example 5]

A solution of 0.84 g (2.8 mmol) of DA-1 and 1.21 g (11.2 mmol) of DA-2 and 4.01 g (14.0 mmol) of DA-3 were placed in a 100 ml four- necked flask equipped with a stirrer and a nitrogen- ), 72.6 g of N-methyl-2-pyrrolidone was added, and dissolved with stirring while nitrogen was being supplied. While this diamine solution was stirred under water cooling, 2.67 g (10.1 mmol) of CA-3 was added. After stirring for 2 hours, 3.66 g (16.8 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added thereto so that the solid content concentration became 12 mass%, and the mixture was stirred for 20 hours under a nitrogen atmosphere To obtain a solution of polyamic acid (A5). The viscosity of this polyamic acid (A5) solution at 25 占 폚 was determined by an E-type viscometer (manufactured by Toki Industries Co., Ltd.), and found to be 358 mPa 占 퐏.

To 50.59 g of this polyamic acid (A5) solution were added 14.51 g of N-methyl-2-pyrrolidone, 5.66 g of a N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane and 23.59 g of butyl cellosolve was added to obtain a liquid crystal aligning agent having a concentration of A5 of 6.0% by mass.

[Comparative Example 6]

7.97 g (40.0 mmol) of DA-6 was placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 98.6 g of N-methyl-2-pyrrolidone was added, . While stirring the diamine solution under water-cooling, 6.96 g (35.5 mmol) of CA-2 and 35.9 g of N-methyl-2-pyrrolidone were added and stirred for 3 hours under nitrogen atmosphere. Thereafter, 1.98 g (10.0 mmol) of DA-5 and 17.9 g of N-methyl-2-pyrrolidone were added and dissolved by stirring. After DA-5 was dissolved, 3.00 g (10.0 mmol) of CA-4 and 26.9 g of N-methyl-2-pyrrolidone were added and stirred for 3 hours under nitrogen atmosphere to obtain polyamic acid ) Was obtained. The viscosity of this polyamic acid (A6) solution at 25 占 폚 was determined by an E-type viscometer (manufactured by Toki Industries Co., Ltd.) and found to be 165 mPa 占 퐏.

To 50.00 g of this polyamic acid (A6) solution were added 10.55 g of N-methyl-2-pyrrolidone, 4.9 g of an N-methyl-2-pyrrolidone solution containing 1.0% by mass of 3-aminopropyltriethoxysilane, 16.37 g of butyl cellosolve was added to obtain a solution having a concentration of A6 of 6.0% by mass.

Further, 24.67 g of N-methyl-2-pyrrolidone and 18.66 g of butyl cellosolve were added to 50.00 g of the polyamic acid solution of A1 to obtain a liquid crystal alignment system having a concentration of A1 of 6.0% by mass. These two 6.0 mass% solutions were mixed in an amount such that A1: A6 was 2: 8 to obtain a polyamic acid solution A7.

Evaluation samples such as films and liquid crystal cells were prepared in the same manner as in Example 1 using the liquid crystal aligning agents obtained in Examples 2 to 13 and Comparative Examples 1 to 6 and evaluated for rubbing resistance, luminous transmittance evaluation, And the residual image was evaluated by long-term driving. The obtained results are shown in Table 3.

In the films formed using the liquid crystal aligning agents of Examples 1 to 13, the rubbing resistance was good and the transmittance was good. In addition, when applied as a liquid crystal alignment film in the evaluation of a liquid crystal cell, there was no temperature dependency of the residual image evaluation, and the result of the residual image evaluation by long-term driving was also good.

On the other hand, in the liquid crystal alignment films formed using the liquid crystal aligning agents of Comparative Examples 1 to 6, it is difficult to combine the afterimage characteristic, the high transmittance and the rubbing resistance, and all these items can not be said to be good. In Comparative Example 1 and Comparative Example 2 in which DA-1 was not used as the diamine component and Comparative Example 5 in which the amount of DA-1 used as the diamine component was small, it was found that the rubbing resistance was poor.

Comparative Example 4 in which CA-1 was not used as the tetracarboxylic acid derivative component and Comparative Example 3 in which the amount of the tetracarboxylic acid derivative component was small showed poor afterimage recovery at 23 占 폚. In Comparative Example 4, The results were also bad.

It was also found that a high luminous transmittance was not obtained in Comparative Example 6 in which DA-1 was not used.

Industrial availability

By using the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal alignment film having a high transmittance, excellent rubbing resistance, and improved display defects such as after-image in a wide temperature range. The liquid crystal alignment film can be used in a liquid crystal display device for a mobile phone or a tablet device in which a large display liquid crystal television which has conventionally required a high display quality is required, and an improvement in the display quality in recent years is required .

The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2011-235976 filed on October 27, 2011 are hereby incorporated herein by reference as the disclosure of the present invention.

Claims (1)

All inventions described herein.