TW201333075A - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

Provided are: a liquid crystal aligning agent which is capable of forming a liquid crystal alignment film that has high transmittance and high rubbing resistance, while achieving an improvement in display failure over a wide temperature range; a liquid crystal alignment film; and a liquid crystal display element. A liquid crystal aligning agent which contains a polyimide precursor that is obtained by reacting a diamine containing from 20% by mole to 100% by mole (inclusive) of a diamine represented by formula (1) with a tetracarboxylic acid derivative containing 50% by mole or more but less than 100% by mole of an aromatic tetracarboxylic acid derivative, or alternatively a polyimide precursor that is obtained by reacting a diamine containing 20% by mole or more but less than 100% by mole of a diamine represented by formula (1) with a tetracarboxylic acid derivative containing from 50% by mole to 100% by mole (inclusive) of an aromatic tetracarboxylic acid derivative. (In the formula, X represents O or S; each of Y1 and Y2 represents a single bond, -O-, -S-, -OCO- or COO-; and each of R1 and R2 represents an alkylene group having 1-3 carbon atoms.)

Description

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

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 phase difference plate or the like using a liquid crystal display element or a polymerizable liquid crystal, and is a film for controlling the alignment direction of liquid crystal molecules to be constant. The liquid crystal alignment film is a very important constituent member for liquid crystal display elements and the like at the same time as liquid crystal.

In recent years, in the field of increasingly advanced liquid crystal display elements, the liquid crystal alignment film is required to have a property of controlling the alignment of liquid crystals (hereinafter also referred to as liquid crystal alignment), and is also required to have heat resistance or solvent resistance. Further, in order to make the liquid crystal display element exhibit high performance, various other characteristics are also required.

As a characteristic obtained on the liquid crystal alignment film, it is a characteristic for improving the display quality of the liquid crystal display element. For example, in the liquid crystal display device, improvement in display failure is required, and as a countermeasure against display failure, the characteristics of the liquid crystal alignment film are required to be improved.

In particular, in the end of the recent rapid and high-definition mobile phone or tablet type, a high display quality is required for the liquid crystal display element to be used. As a result, the specifications for the display failure of the so-called "after-image phenomenon" or simply "after-image" are becoming more and more severe. For example, even if an afterimage is generated, realization of a liquid crystal alignment film having characteristics that it is necessary to quickly disappear is expected. For recent years The liquid crystal display element is not restricted to indoors due to the use environment, so it is expected to be outside. The high temperature environment in the car also has high quality performance, and the liquid crystal alignment film which does not change at room temperature and high temperature is obtained.

Moreover, it is expected that the liquid crystal display element will be low in power consumption at the end of the mobile terminal. For such a portable terminal, since the liquid crystal display element is low in power consumption, it can be used for a long period of time under battery charging. For the low power consumption of the liquid crystal display element, the high transmittance of the liquid crystal display element is effective. Therefore, in the liquid crystal display device, it is expected that the transmittance is improved for a constituent member such as a liquid crystal alignment film at the same time as a high aperture ratio of the pixel.

Further, the liquid crystal alignment film is expected to have high resistance to the rubbing treatment from the viewpoint of applicability to the manufacturing steps of the liquid crystal display element. A method of forming a liquid crystal alignment film in the manufacturing steps of a liquid crystal display element is known for the rubbing treatment, and is now widely used in the industry. For the rubbing treatment, a polymer film such as polyimide or a polyimide film is formed on the substrate, and the surface thereof is wiped with a cloth to perform an alignment treatment.

In the rubbing treatment, there is a problem that the liquid crystal alignment film is generated by dust generated during cutting or a flaw attached to the liquid crystal alignment film to lower the display quality. Therefore, the resistance of the liquid crystal alignment film to the rubbing treatment (hereinafter also referred to as rubbing resistance) is expected.

As a method for forming a liquid crystal alignment film having high rub resistance, a method of adding various additives to a polyimine comprising a liquid crystal alignment film or a polyimine precursor to form a polyimine is known. (For example, refer to Patent Documents 1 and 2).

Others have proposed a polyimine structure or the like having good rubbing resistance (for example, refer to Patent Documents 3 and 4).

By such a method, it is possible to make the liquid crystal alignment film grinding (also referred to as abrasion) or the liquid crystal alignment film scratch (also referred to as abrasion) in the rubbing treatment difficult to produce.

However, in recent years, in some applications of liquid crystal display elements, in the rubbing treatment, a polymer film such as polyimine has a tendency to be wiped by a cloth and subjected to alignment treatment. Such a strong rubbing treatment is intended to make the liquid crystal alignment state more uniform and stronger. Therefore, for the liquid crystal alignment film, a higher level of rub resistance is required.

[prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 7-120769

[Patent Document 2] Japanese Patent Laid-Open No. Hei 9-146100

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-90297

[Patent Document 4] Japanese Patent Laid-Open Publication No. Hei 9-258229

An object of the present invention is to provide a liquid crystal alignment agent which has a high liquid crystal alignment property and abrasion resistance, and which has an afterimage reduction effect on a liquid crystal display element over a wide temperature range and which can form a high light transmittance.

Further, an object of the present invention is to provide a liquid crystal alignment agent as described above, which has high liquid crystal alignment and rub resistance, and is widely used for liquid crystal display elements. The afterimage in the over-temperature range is reduced in the liquid crystal alignment film which is effective and has high light transmittance. Further, a liquid crystal display element having the liquid crystal alignment film is provided.

The inventors of the present invention have completed the present invention by repeating the detailed review results to solve the above problems.

That is, the present invention has the following gist.

(1) A liquid crystal alignment agent which is a liquid crystal alignment agent containing a polyimide precursor obtained by reacting a diamine component with a tetracarboxylic acid derivative, and is characterized in that the diamine component contains 20 mol% or more. a diamine compound represented by the following formula (1) in an amount of 100 mol% or less, and the tetracarboxylic acid derivative is an aromatic tetracarboxylic derivative containing 50 mol% or more and less than 100 mol% Or the diamine component is a diamine compound represented by the following formula (1) containing 20 mol% or more and less than 100 mol%, and the tetracarboxylic acid derivative contains 50 mol% or more and 100 mol%. An aromatic tetracarboxylic acid derivative having a content of less than %.

(In the formula (1), X is an oxygen atom or a sulfur atom, and Y ¹ and Y ^{2 are} independently a single bond, -O-, -S-, -OCO-, or COO-, and R ¹ and R ^{2 are} independently a carbon number. 1~3 alkyl group)

(2) The diamine component further contains the following formula (AM1) A liquid crystal alignment agent according to (1) above, which is a diamine compound.

(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 base)

(3) In the diamine compound represented by the above formula (AM1), R ⁵ is selected from the group consisting of the above formula (a-1), formula (a-4), formula (a-5), and formula (a-6). A liquid crystal alignment agent according to the above (2), which is a diamine compound having a single structure of the formula (a-10), the formula (a-16), the formula (a-19), and the formula (a-20).

(4) The liquid crystal alignment according to any one of the above (1) to (3), wherein the diamine component contains 50 mol% or more and less than 100 mol% of the diamine compound of the formula (1). Agent.

(5) The tetracarboxylic acid derivative is any one of the above (1) to (4) selected from the group consisting of a compound represented by the following formula (2-a) to the formula (2-e); The liquid crystal alignment agent described.

(In the formula (2-a) to the formula (2-e), R ⁷ represents an alkyl group, and R ⁶ represents a structure having a group selected from the group consisting of the following formulas (b-1) to (b-8). 4-valent organic base)

(6) The tetracarboxylic acid derivative is the liquid crystal alignment agent of the above (5) of the above formula (2-a).

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

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

The present invention can provide a liquid crystal alignment agent which has high liquid crystal alignment and rub resistance, is effective for reducing the afterimage of a liquid crystal display element, and can form a liquid crystal alignment film having high light transmittance.

Further, the present invention can provide a liquid crystal alignment film which has high liquid crystal alignment property and abrasion resistance and which is effective for reducing the afterimage of a liquid crystal display element and has high light transmittance.

Further, the present invention can provide a liquid crystal display element using a liquid crystal alignment film having the above characteristics.

Type of implementation of the invention

The liquid crystal alignment agent of the present invention contains a polyimine precursor obtained by reacting a diamine component with a tetracarboxylic acid derivative. As a polyimide precursor, it contains poly-proline, polyphthalate, and the like.

The polyimine precursor contained in the liquid crystal alignment agent of the present invention is a tetracarboxylic acid derivative which is preferably realized by a desired property by a combination of a diamine component having a characteristic structure and the diamine component. form.

Hereinafter, the diamine component and the tetracarboxylic acid derivative used in order to obtain the polyimine precursor contained in the liquid crystal alignment agent of the present invention will be described in detail.

<Specific diamine compound (1)>

The liquid crystal alignment agent of the present invention is a specific component of the specific structure represented by the following formula (1), which is a diamine component of a polyimine precursor such as polyglycolic acid or polyglycolate to be contained. Amine compound.

In the above formula (1), X is an oxygen atom or a sulfur atom, and Y ¹ and Y ^{2 are} independently a single bond, -O-, -S-, -OCO-, or COO-, and R ¹ and R ^{2 are} independently a carbon number. 1 to 3 alkyl groups.

When X in the above formula (1) is an oxygen atom, the specific diamine compound of the above formula (1) is a diamine compound having a urea group, and when X is a sulfur atom, it has a thiourea group (hereinafter sometimes urea) The base and the thiourea group are collectively referred to as (thio)ureido) diamine compounds.

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

The diamine component of the polyimine precursor which is contained in the liquid crystal alignment agent of the present invention contains the specific diamine compound of the above formula (1) as an essential component, but the content of the specific diamine compound contained therein may be Is any value.

In the liquid crystal alignment film obtained by the liquid crystal alignment agent of the present invention, in order to obtain sufficient rub resistance, in the total diamine component (100 mol%), the specific diamine compound of the above formula (1) is preferably 20 mol% or more. Preferably, it is 30 mol% or more, more preferably 50 mol% or more.

In addition, the polyimine precursor contained in the liquid crystal alignment agent forms a polyimine, and the liquid crystal display element is optimized as a liquid crystal display element, and the pretilt angle of the liquid crystal is optimized, or the charge is reduced. The content of the specific diamine compound represented by the formula (1) is preferably less than 100 mol%, preferably 30 to 60%, based on the total diamine component.

When the content of the specific diamine compound represented by the above formula (1) is 100 mol% in the total diamine component, that is, when the diamine component is a specific diamine compound represented by the above formula (1), it is used as described later. The content of the aromatic tetracarboxylic acid derivative in the tetracarboxylic acid derivative in the formation of the polyimine precursor is 50 mol% or more and less than 100 mol% in the all tetracarboxylic acid component. Therefore, in the liquid crystal alignment agent of the present invention, the diamine component is a specific diamine compound of the above formula (1), and the tetracarboxylic acid derivative is not all aromatic tetracarboxylic acid. Acid derivative.

<Diamine compound (AM1)>

The polyimine precursor contained in the liquid crystal alignment agent of the present invention is obtained by a 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.

Further, when the diamine component of the polyimine precursor of the present invention is obtained, the diamine compound represented by the following formula (AM1) is used together with the specific diamine compound represented by the above formula (1). The reaction of the tetracarboxylic acid derivative is preferred.

In the above 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-19), and R ³ and R ⁴ independently represent a hydrogen atom. Or a monovalent organic group.

The diamine compound represented by the above formula (AM1) is obtained by forming a polyimine from a polyimide precursor contained in a liquid crystal alignment agent, and reducing the afterimage when the liquid crystal alignment film is used as a liquid crystal display element. It is to be noted that R ⁵ has a formula (a-1), a formula (a-4), a formula (a-5), a formula (a-6), a formula (a-10), and a formula (a-16). A diamine compound having one structure in the group of the formula (a-19) and the formula (a-20) is preferred. Particularly preferred is a diamine compound having one structure selected from the group consisting of (a-1), (A-4), (A-19) and (a-20).

In addition, the diamine component of the polyimine precursor which is contained in the liquid crystal alignment agent of the present invention may contain the diamine compound represented by the above formula (AM1) as an essential component of the specific diamine compound of the above formula (1). However, it is also possible to contain a diamine compound other than this.

In other words, the diamine component of the polyimine precursor which is contained in the liquid crystal alignment agent of the present invention may contain the specific diamine compound of the above formula (1) and the above formula without departing from the effects of the present invention. A diamine compound other than the diamine compound of (AM1).

<tetracarboxylic acid derivative>

The tetracarboxylic acid derivative which can be used in order to obtain the polyimine precursor contained in the liquid crystal alignment agent of the present invention is not particularly limited.

Examples of the tetracarboxylic acid derivative of the present invention include tetracarboxylic dianhydride (shown by the following formula (2-a)), tetracarboxylic acid monoanhydride (shown by the following formula (2-b)), and four. a carboxylic acid (shown by the following formula (2-d)), a dialkyl dicarboxylate (shown by the following formula (2-c)), a dicarboxylic acid chloride dialkyl ester (the following formula (2) -e) shown) and so on. The tetracarboxylic acid derivative is only required to be reacted with a diamine, and is not limited thereto.

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

Wherein R ⁷ represents an alkyl group.

Further, specific examples of R ⁶ include the following formula [A-1] to formula [A-47].

The tetracarboxylic acid derivative which can be used in order to obtain the polyimine precursor contained in the liquid crystal alignment agent of the present invention is particularly preferably used as an aromatic tetracarboxylic acid derivative. All tetracarboxylic acid derivatives may be aromatic tetracarboxylic acid derivatives.

In order to obtain the above polyimine precursor, two or more kinds of tetracarboxylic acid derivatives can be used, and it can be used for the reaction with a diamine component. In this case, it is preferred that one or more aromatic tetracarboxylic acid derivatives are contained in the tetracarboxylic acid derivative.

Further, when all the tetracarboxylic acid derivatives are aromatic tetracarboxylic acid derivatives, two or more kinds of aromatic tetracarboxylic acid derivatives having different structures may be used.

By containing an aromatic tetracarboxylic acid derivative, the tetracarboxylic acid derivative can be used for the formation of a polyimide precursor, and the liquid crystal alignment property of the obtained liquid crystal alignment film can be improved. In this case, the total amount of the tetracarboxylic acid derivative to be used is preferably 50 mol% or more of the aromatic tetracarboxylic acid derivative. However, when the diamine component used for the formation of the polyimide precursor is the diamine compound represented by the above formula (1), as described above, the content of the aromatic tetracarboxylic acid derivative is derived from the tetracarboxylic acid used. The total amount is less than 100% by mole.

The preferred aromatic tetracarboxylic acid derivative to be used for obtaining the polyimine precursor contained in the liquid crystal alignment agent of the present invention is selected from the above formula (2-a) to formula (2-e). In the compound of the above-mentioned compound, R ⁷ represents an alkyl group, and R ⁶ represents a tetravalent organic compound having one structure selected from the group consisting of the following formulas (b-1) to (b-8). A base, an aromatic tetracarboxylic acid derivative.

The above-described formula (2-a) ~ the formula (2-e) as shown, R ⁶ above formula (b-1) an aromatic tetracarboxylic acid derivative structure shown in the above-described specific examples of R ⁶ corresponds to the formula a tetracarboxylic acid derivative of [A-26].

Likewise, R ⁶ is a configuration of an aromatic tetracarboxylic acid derivative (b-2) shown in the above formula, specific examples of R ⁶ corresponds to the formula [A-27] The tetracarboxylic acid derivative.

R ⁶ is an aromatic tetracarboxylic acid derivative represented by the above structure formula (b-3), a specific R ⁶ corresponds to the above embodiment of formula [A-28] The tetracarboxylic acid derivative.

R ⁶ is an aromatic tetracarboxylic acid derivative represented by the above structural formula (b-4), the specific examples of R ⁶ corresponds to the formula [A-29] The tetracarboxylic acid derivative.

R ⁶ above formula [A-31] of the above-described tetracarboxylic acid derivative of formula (b-5) an aromatic tetracarboxylic acid derivative structure shown in specific examples of R ⁶ corresponds.

R ⁶ is an aromatic tetracarboxylic acid derivative represented by the above structural formula (b-6), a specific R ⁶ corresponds to the above embodiment of formula [A-30] The tetracarboxylic acid derivative.

R ⁶ is an aromatic tetracarboxylic acid derivative represented by the above structural formula (b-7), the specific examples of R ⁶ corresponds to the formula [A-32] The tetracarboxylic acid derivative.

R ⁶ is an aromatic tetracarboxylic acid derivative represented by the above structure formula (b-8), a specific R ⁶ corresponds to the above embodiment of formula [A-47] The tetracarboxylic acid derivative.

The particularly preferred aromatic tetracarboxylic acid derivative used for obtaining the polyimine precursor contained in the liquid crystal alignment agent of the present invention is selected from the above formula (2-a) to formula (2-e). One or more compounds in which the compounds are grouped, R ⁷ is an alkyl group, and R ⁶ is an aromatic tetracarboxylic acid having a structure represented by the above formula (b-1), formula (b-2) or formula (b-7). Acid derivative.

<Polyimide precursor>

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

The diamine component containing the specific diamine compound of the above formula (1) as an essential component and a tetracarboxylic acid derivative containing an aromatic tetracarboxylic acid derivative are reacted to obtain a polyimide precursor.

An example of using a tetracarboxylic dianhydride as a tetracarboxylic acid derivative is as follows.

Polyimine precursor used in the liquid crystal alignment agent of the present invention The polymerization reaction method of the produced diamine component and the tetracarboxylic acid derivative is not specifically limited. In an organic solvent, they may be mixed and then subjected to a polymerization reaction to form a poly-proline which is a polyimide precursor. Further, when the polyamic acid is esterified with a known esterifying agent to obtain a carboxylic acid group, a polyphthalate can be obtained. The polyimine can be obtained by subjecting the obtained polylysine and polyphthalate to dehydration ring closure.

A method of mixing a diamine component and a tetracarboxylic acid derivative in an organic solvent, a method of stirring a solution in which a diamine component is dispersed or dissolved in an organic solvent, and directly adding a tetracarboxylic acid derivative component, or A method in which a tetracarboxylic acid derivative component is dispersed or dissolved in an organic solvent and then 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, or a method of mutually adding a tetracarboxylic acid derivative and a diamine may be mentioned. Further, when at least one of the tetracarboxylic acid derivative component and the diamine is formed of a plurality of compounds, the plurality of components may be subjected to a polymerization reaction in a state of being mixed in advance, or a polymerization reaction may be carried out in a separate order.

The temperature at which the diamine component and the tetracarboxylic acid derivative are polymerized in an organic solvent is usually from 0 to 150 ° C, preferably from 5 to 100 ° C, preferably from 10 to 80 ° C. The polymerization reaction ends earlier in the higher temperature, but if it is too high, a high molecular weight polymer cannot be obtained. Further, the polymerization reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a polymer having a high molecular weight, and when the concentration is too high, the viscosity of the reaction liquid is too high and uniform. The stirring becomes difficult, so it is preferably 1 to 50% by mass, preferably 5 to 30% by mass. The initial stage of the polymerization is carried out at a high concentration, and then an organic solvent can be added. Agent. Further, the above-described loading concentration is a concentration in which the total mass of the diamine component and the tetracarboxylic acid derivative is combined.

The organic solvent used in the above polymerization reaction is not particularly limited as long as it is a polylysine which can be dissolved and a polyglycolate (hereinafter sometimes referred to as polyglycolic acid). Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, and dimethyl group. Azulene, tetramethyl urea, pyridine, dimethyl hydrazine, hexamethylarylene, γ-butyrolactone and the like. These can be used alone or in combination. Further, it may be a solvent which does not dissolve polyglycolic acid (ester), and may be used after being mixed with the above solvent in the range in which the produced polyglycolic acid (ester) is not precipitated.

Further, since the water in the organic solvent hinders the polymerization reaction and causes the polyamic acid (ester) formed by the hydrolysis, it is preferred that the organic solvent is used as it is after dehydration.

The ratio of the tetracarboxylic acid derivative to the diamine used for obtaining the polymerization reaction of polylysine is preferably from 1:0.8 to 1:1.2 for the molar ratio, and the closer the molar ratio is to 1:1. The larger the molecular weight of the obtained poly-proline. If the molecular weight of the polyglycolic acid (ester) is too small, the strength of the obtained coating film is not sufficient. Conversely, if the molecular weight of the polyamic acid (ester) is too large, the viscosity of the obtained liquid crystal alignment agent is too high, and the coating film is too high. The workability at the time of formation, the uniformity of the coating film, and the like may be deteriorated. Therefore, the polyglycolic acid (ester) used in the liquid crystal alignment agent of the present invention has a weight average molecular weight of preferably 2,000 to 500,000, preferably 5,000 to 300,000.

The polyphthalic acid (ester) contained in the liquid crystal alignment agent of the present invention is composed of two The reaction of the amine component with the tetracarboxylic acid derivative is carried out, and as the diamine component, the specific diamine compound represented by the above formula (1) is used as an essential component.

Further, as the diamine component, in addition to the specific diamine compound represented by the above formula (1), a diamine component containing the diamine compound represented by the above formula (AM1) may be used, or two other components may be further used. a diamine component of an amine compound.

As the tetracarboxylic acid derivative, the use of the tetracarboxylic acid derivative containing the above aromatic tetracarboxylic acid derivative is preferred.

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

Further, the polyglycolate can be represented by the following formula (4).

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

Using the specific diamine compound represented by the above formula (1), R ^a and R ^b are a hydrogen atom, and R ^c is a -phenyl-Y ¹ -NH-CX-HN-R ² -Y ² -phenylene group. When the 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 formula (2-a) to formula (2-e).

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

The polyamic acid or polyphthalate obtained as described above can be directly used in the liquid crystal alignment agent of the present invention. Further, the liquid crystal alignment agent of the present invention may further contain a polyimine which is subjected to dehydration ring closure of the polylysine or polyglycolate obtained as described above.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention contains the polyimine precursors obtained as described above, and generally, the polymer is dissolved in an organic solvent to form a coating liquid.

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

The content of the polyimine precursor in the liquid crystal alignment agent of the present invention is preferably from 1 to 20% by mass, and preferably from 2 to 20% by mass, based on the total amount of the liquid crystal alignment agent.

The organic solvent contained in the liquid crystal alignment agent of the present invention is not particularly limited as long as it can dissolve only the polymer contained therein.

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

Specific examples of the organic solvent used in the liquid crystal alignment agent of the present invention include N,N-dimethylformamide, N,N-dimethylacetamide, and N- Methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl hydrazine, tetramethyl urea, pyridine, dimethyl hydrazine, six Methyl hydrazine, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, and the like. These can be used alone or in combination of two or more.

Further, the solvent of the polymer such as the polyimine precursor or the polyimide may not be dissolved alone, and may be mixed with the liquid crystal alignment agent of the present invention in the range in which the polymer is not precipitated.

Especially ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1- Ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl Ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, lactic acid A solvent having a low surface tension such as N-propyl ester, N-butyl lactate or isoamyl lactate can improve the uniformity of coating of the liquid crystal alignment agent to the substrate by mixing. When these solvents are used, they can be used in one type or in a mixture of plural types.

The liquid crystal alignment agent of the present invention is preferably a solvent having a low surface tension, and the amount thereof is preferably from 5 to 80% by mass, more preferably from 20 to 60% by mass, based on the total amount of the solvent contained in the liquid crystal alignment agent. .

The liquid crystal alignment agent of the present invention may contain various additives in addition to the above-mentioned polyimine precursor, polymer such as polyimine, and an organic solvent, without impairing the effects of the present invention.

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

Specific examples include Eftop EF 301, EF 303, and EF 352 (manufactured by Tohken Products Co., Ltd.), Megafac F171, F173, R-30 (manufactured by Dainippon Ink Co., Ltd.), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard AG 710, and Surfon S-. 382, SC101, SC102, SC103, SC104, SC105, SC106 (made by Asahi Glass Co., Ltd.). The use ratio of the surfactant 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 alignment agent.

The liquid crystal alignment agent of the present invention may contain an additive which improves the adhesion between the formed liquid crystal alignment film and the substrate. Specific examples of such an additive include a compound containing a functional decane, a compound containing an epoxy group, and the like.

Examples thereof include 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2-aminopropyltriethoxydecane. N-(2-Aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxydecane, 3-urea Propyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxycarbonyl-3-aminopropyltri Ethoxy decane, N-triethoxymethane alkyl propyl triethylamine, N-trimethoxymethyl propyl propyl triethylamine, 10-trimethoxymethyl decyl-1 ,4,7-triazadecane, 10-triethoxymethylidene-1,4,7-three Azadecane, 9-trimethoxycarbamido-3,6-diazaindolyl acetate, 9-triethoxycarbamido-3,6-diazaindolyl acetate, N-Benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane , N-phenyl-3-aminopropyltriethoxydecane, N-bis(oxirane)-3-aminopropyltrimethoxydecane, N-bis(ethylene oxide)-3 -Aminopropyltriethoxydecane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl Ester ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N',-tetraglycidyl ester-m-xylenediamine, 1,3-double (N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N',-tetraglycidyl-4,4'-diaminodiphenylalkane, and the like.

When 100% by mass of the polymer component contained in the liquid crystal alignment agent is added, it is preferably 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass. When the amount is less than 0.1 part by mass, the adhesion improving effect cannot be expected, and when it exceeds 30 parts by mass, the liquid crystal alignment property of the formed liquid crystal alignment film may be lowered.

In addition to the above-mentioned additives, the liquid crystal alignment agent of the present invention can be added to a polymer component other than the polymer, and the electrical properties such as the electric conductivity of the liquid crystal alignment film or the electrical conductivity can be changed without impairing the effects of the present invention. Further, a crosslinkable compound or the like which can improve the film hardness or density when the liquid crystal alignment film is used can be added to the electric material or the conductive material.

The concentration of the solid component in the liquid crystal alignment agent of the present invention can be appropriately changed depending on the film thickness of the intended liquid crystal alignment film. Further, a coating film having no defects is formed, and a suitable film thickness as a liquid crystal alignment film can be obtained, and the concentration of the polymer is preferably 1 to 20% by mass, preferably 2 to 10% by mass.

Further, the liquid crystal alignment agent of the present invention may be blended with a soluble polyimine, polylysine, polyamine or the like which is formed of a dissimilar molecular structure at the same time as the polyimine precursor. It contains. At this time, in view of the desired properties of the obtained polyimide film, the content of the above-mentioned polyimine precursor of the present invention is combined with other soluble polyimine, polylysine, or polyamine. The total amount (100 mol%) such as an acid ester is preferably from 5 to 95 mol%, more preferably from 10 to 90 mol%.

The liquid crystal alignment agent of the present invention is applied to a substrate and coated with a film, and after firing, it is subjected to an alignment treatment by rubbing treatment or light irradiation, and then used as a liquid crystal alignment film or in a vertical alignment application, and is not subjected to alignment treatment. Can be used as a liquid crystal alignment film.

The substrate to be used is only a substrate having high transparency, and is not particularly limited. For example, a plastic substrate such as a glass substrate, an acrylic substrate, or a polycarbonate substrate can be used, and when a substrate formed of an ITO (Indium Tin Oxide) electrode to be liquid-crystal-driven is used, it is preferable from the viewpoint of simplifying the process. Further, when a reflective liquid crystal display device is formed, an opaque substance such as a germanium wafer can be used only on the single-sided substrate. As the electrode at this time, a material that reflects light such as aluminum can also be used.

The coating method of the liquid crystal alignment agent is not particularly limited, and industrially, coating methods such as screen printing, offset printing, flexographic printing, and inkjet printing can be used. law. As another coating method, a coating method such as a dipping, a roll coater, a slit coater, or a rotor can be used, and it can be used for the purpose.

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

When the liquid crystal alignment agent contains polyglycolic acid or polyglycolate, the conversion rate of the polyimine is changed depending on the firing temperature, but the liquid crystal alignment agent of the present invention does not need to be 100%. Imine.

Further, the coating film firing time of the liquid crystal alignment agent can be set to any time. If the firing time is too short, display failure may occur due to the influence of the residual solvent, and it is preferably 5 to 60 minutes, more preferably 10 to 40 minutes.

When the thickness of the coating film after firing is too thick, it is disadvantageous in terms of the power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. Therefore, the thickness of the coating film is preferably from 5 to 300 nm, more preferably from 10 to 100 nm.

When the liquid crystal is horizontally aligned or obliquely aligned, it is preferred that the coating film after firing is subjected to alignment treatment by rubbing or polarized ultraviolet rays.

<Liquid crystal display element>

In the liquid crystal display device of the present invention, a substrate having an electrode or the like is used, and a substrate having a liquid crystal alignment film is obtained from the liquid crystal alignment agent of the present invention by the above method, and a liquid crystal cell is produced by a known method, and can be used as a liquid crystal display element. .

The method for producing the liquid crystal cell can be, for example, as shown below.

It is prepared to form a pair of bases such as an electrode to be driven by a liquid crystal on at least one of them board. On the pair of substrates, a liquid crystal alignment film of the present invention is prepared, and a liquid crystal alignment film forms a pair of substrates. Next, the spacer is dispersed on the liquid crystal alignment film of the single substrate, the liquid crystal alignment film surface is placed inside, and the other single substrate is bonded, and the liquid crystal is injected under reduced pressure to be sealed. The liquid crystal display element is manufactured as follows.

In addition, after a pair of substrates formed by the liquid crystal alignment film of the present invention are prepared, liquid crystal is dropped onto the liquid crystal alignment film surface of the dispersion spacer, and then these substrates are bonded and sealed to produce a liquid crystal display element. Further, the spacer thickness at this time is preferably from 1 to 30 μm, more preferably from 2 to 10 μm.

As described above, the liquid crystal display element of the present invention produced by using the liquid crystal alignment agent of the present invention has excellent display quality with reduced afterimage development and high luminance with excellent signalability. Therefore, it can be suitably utilized for a high-definition liquid crystal television in a large screen, or a display element such as a smart phone or a tablet type device.

[Examples]

The following examples and comparative examples are specifically described by the present invention, but the present invention is not limited to these examples.

The abbreviations used in the examples and comparative examples are as follows.

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

DA-2: p-phenylenediamine

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

DA-4: N-methyl 4-aminophenethylamine

DA-5: 4,4'-diaminodiphenylalkane

DA-6: 4,4'-diaminodiphenylamine

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

CA-1: pyromellitic dianhydride

CA-2: 1,2,3,4-cyclobutane tetracarboxylic dianhydride

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

CA-4: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride

CA-5: dimethyl 2,5-terephthalate

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

[Example 1]

In a 200 ml four-a beaker equipped with a stirring device and a nitrogen inlet tube, 8.96 g (30.0 mmol) of DA-1 and 3.24 g (30.0 mmol) of DA-2 were added, and N-methyl-2-pyrrolidone was added thereto. 141 g was stirred and dissolved while carrying nitrogen gas. Next, while stirring the diamine solution, 12.82 g (58.7 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the temperature was 20 hours at a water temperature in a nitrogen atmosphere. Stirring to obtain a solution of polyamic acid (P1). The viscosity of the polylysine (P1) solution at 25 ° C was 297 mPa when confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.). s.

To 50.30 g of the polyamic acid (P1) solution, 23.37 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. 5.83g, and butyl cellosolve 26.49g, The liquid crystal alignment agent having a concentration of P1 of 5.5% by mass.

Table 1 shows the amount (mol) of each tetracarboxylic acid derivative component used in the synthesis of polyamic acid A1 and the amount of each diamine component (mole).

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

Further, Table 2 shows A7 of a mixed liquid of polylysine.

(resistance evaluation)

The obtained liquid crystal alignment agent was filtered through a 1.0 μm filter, spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at 50° C. for 5 minutes, and then fired at 230° C. for 30 minutes. A polyimide film having a film thickness of 70 nm was obtained. The polyimide film was rubbed with a crepe cloth (roll diameter: 120 mm, number of revolutions: 1000 rpm, moving speed: 30 mm/sec, and pushing amount: 0.4 mm). The surface of the film was observed using a confocal laser microscope (manufactured by Laser Dick), and the presence or absence of the shavings and the size thereof were observed at a magnification of 10 times. When the film was cut by a large amount of rubbing or when a film having a size of 30 μm or more was produced, it was judged as "poor". When such a phenomenon has not occurred, it is judged that the rub resistance is "good". The evaluation results are shown in Table 3.

(Density measurement (visual transmittance (Y value (%)))

The obtained liquid crystal alignment agent was filtered through a 1.0 μm filter, and then spin-coated with an alignment agent on a quartz substrate, dried on a hot plate at 50° C. for 5 minutes, and then fired at 230° C. for 30 minutes. Film thickness 70 nm polyimine film. The two-side patch is bonded only to both sides of the coating film surface facing the substrate, and is bonded to the quartz substrate on which the film is not formed. The liquid paraffin was injected into the obtained simple container, and the transmittance was measured using UV-3100PC manufactured by Shimadzu Corporation. The visual transmittance was calculated from the obtained data. The evaluation value was defined as "good" when the value was 96% or more, and the "bad" was determined when the value was less than 96%. The evaluation results are shown in Table 3. The visual transmittance was calculated using the software for sale (color measurement software manufactured by Shimadzu Corporation: P/N206-65207).

(production of liquid crystal cell)

A liquid crystal cell having a configuration of an IPS (In-Planes Switching) mode liquid crystal display element is prepared.

First, prepare a substrate with an electrode attached. The substrate was a glass substrate having a size of 30 mm × 50 mm and a thickness of 0.7 mm. A counter electrode as a first layer was formed on the substrate, and an ITO electrode having a solid pattern was formed. A SiN (tantalum nitride) film which is a second layer and is formed by a CVD method is formed on the counter electrode of the first layer. The SiN film of the second layer has a film thickness of 500 nm and functions as an interlayer insulating film. On the SiN film of the second layer, an ITO film as a third layer was formed, and a tooth comb-like pixel electrode was placed to form a second pixel of the first pixel and the second pixel. The dimensions of each pixel are 10 mm in length and 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 tooth comb shape including electrode elements in which a plurality of central portions are bent in a "ㄑ" shape. Electrode element The short direction width was 3 μm, and the spacer between the electrode elements was 6 μm. Since the pixel electrodes forming the respective pixels are composed of electrode elements in which the central portion of the plurality of pixels is bent into a "ㄑ" shape, the shape of each pixel is not rectangular, and the central portion is curved like the electrode elements. A shape similar to the bold font "ㄑ". Each of the pixels has a central curved portion as a boundary and is vertically divided, and has an upper first region and a lower second region having a curved portion.

When the first region and the second region of each pixel are compared, the electrode elements forming the pixel elements are different in the direction in which they are formed. In other words, when the rubbing direction of the liquid crystal alignment film to be described later is used as a reference, the electrode element of the pixel electrode is formed at an angle of +10° (clockwise direction) in the first region of the pixel, and is formed in the second region of the pixel. The electrode elements of the pixel electrodes are formed at an angle of -10° (clockwise). In other words, in the first region and the second region of each pixel, the direction of the rotation (in-plane switching) of the liquid crystal in the substrate surface caused by the voltage input between the pixel electrode and the counter electrode is mutually It is formed in the reverse direction.

Next, the obtained liquid crystal alignment agent was filtered through a 1.0 μm filter, and then spin-coated on each of the prepared electrode-attached substrate and the glass substrate on which the ITO film was formed. Subsequently, the film was dried on a hot plate at 50 ° C for 5 minutes, and then fired at 230 ° C for 30 minutes to form a film having a film thickness of 70 nm, and a polyimide film was obtained on each substrate. The polyimide film was rubbed with a crepe in a predetermined rubbing direction (roller diameter: 120 mm, number of revolutions: 500 rpm, moving speed: 30 mm/sec, and amount of impregnation: 0.3 mm), and then carried out in pure water for 1 minute. Sound wave illumination, and at 80 ° C Dry for 10 minutes.

Thereafter, a 4 μm bead spacer (manufactured by Nikko Kasei Co., Ltd.) was spread only on the single substrate. Two types of substrates with the liquid crystal alignment film thus treated were used, and the rubbing directions were combined to be antiparallel to each other, leaving a liquid crystal injection port to seal the surroundings, and a cell having a cell gap of 3.6 μm was produced. After liquid crystal (MLC-2041, manufactured by Merck) was vacuum-injected into the cells at room temperature, the injection port was sealed and used as an antiparallel alignment liquid crystal cell. The obtained liquid crystal cell constitutes an IPS mode liquid crystal display element. Thereafter, the obtained liquid crystal cell was heated at 110 ° C for 1 hour, and then left for one night and used for each evaluation.

(afterimage recovery time assessment (afterimage evaluation))

The afterimage evaluation was performed using the following optical system or the like.

The produced liquid crystal cell is placed between two polarizing plates arranged such that the polarizing axis is orthogonal, and the LED backlight is turned on while the voltage is not input, and the arrangement angle of the liquid crystal cell is adjusted to minimize the brightness of the transmitted light.

Next, a V-T curve (voltage-transmittance curve) was measured while inputting an AC voltage having a cycle number of 30 Hz to the liquid crystal cell, and an AC voltage having a relative transmittance of 23% was calculated as a driving voltage.

The afterimage was evaluated by inputting an AC voltage of 30 Hz with a relative transmittance of 23%, and driving the liquid crystal cell while simultaneously inputting a DC voltage of 2 V to drive for 120 minutes. Thereafter, the input DC voltage value was set to 0 V, and only the input of the DC voltage was stopped, and in this state, the drive was further performed for 60 minutes.

The afterimage is evaluated as the time from the stop of the input of the DC voltage to 60 After a minute, it was evaluated as "good" when the relative transmittance was restored to 25% or less. The "bad" was evaluated when the time required for the transmittance to return to 25% or less was 60 minutes or longer.

The afterimage evaluation by the above method was carried out under two kinds of temperature conditions of a state in which the temperature of the liquid crystal cell was 23 ° C and a state of 60 ° C. The evaluation results are shown in Table 3.

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

A liquid crystal cell of the same structure as that used for the liquid crystal cell of the afterimage evaluation described above was prepared.

Using this liquid crystal cell, an AC voltage of 8 V _PP was input at a cycle number of 30 Hz for 100 hours in a constant temperature environment of 60 °C. Thereafter, a short circuit state between the pixel electrode of the liquid crystal cell and the counter electrode was set, and in this case, it was left at room temperature for one day.

After being placed, the liquid crystal cell is placed between two polarizing plates arranged so that the polarizing axis is orthogonal, and the backlight is turned on without voltage input, and the arrangement angle of the liquid crystal cells is adjusted to the minimum of the transmitted light brightness. Further, from the darkest angle of the second region of the first pixel to the darkest angle of the first region, the angle of rotation when the liquid crystal cell is rotated is calculated as the angle Δ. Similarly to the second pixel, the second region and the first region are compared, and the same angle Δ is calculated. Further, the average value of the angle Δ values of the first pixel and the second pixel is calculated as the angle Δ of the liquid crystal cell. When the value of the angle Δ of the liquid crystal cell exceeds 0.2 degrees, the evaluation is defined as "poor". When the value of the angle Δ of the liquid crystal cell did not exceed 0.2, it was evaluated as "good". The evaluation results are shown in Table 3.

[Example 2]

In a 200 ml four-beat beaker equipped with a stirring device and a nitrogen inlet tube, 7.46 g (25.0 mmol) of DA-1 and 7.15 g (25.0 mmol) of DA-3 were placed, and N-methyl-2-pyrrolidone was added thereto. 143.3 g was stirred and dissolved while carrying nitrogen gas. While stirring the diamine solution, 10.26 g (47.0 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass. Under a nitrogen atmosphere, the temperature was 20. After stirring for a while, a solution of polyglycine (P2) was obtained. The viscosity of the polyamic acid (P2) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 305 mPa. s.

To 50.40 g of the polyplysine (P2) solution, 22.07 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. 5.74 g of a solution and 26.07 g of butyl cellosolve were used to obtain a liquid crystal alignment agent having a P2 concentration of 5.5% by mass.

[Example 3]

Into a 100 ml four-a beaker equipped with a stirring device and a nitrogen introduction tube, 4.47 g (15.0 mmol) of DA-1 and 1.62 g (15.0 mmol) of DA-2 were added, and N-methyl-2-pyrrolidone was added thereto. 62.9 g was stirred and dissolved while carrying nitrogen gas. 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 the mixture was stirred while supplying nitrogen gas. After stirring for 3 hours, add 5.04 g (23.1 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred at a water temperature for 20 hours in a nitrogen atmosphere to obtain a poly-proline (P3). ) a solution. The viscosity of the polyamic acid (P3) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 280 mPa. s.

To 83.48 g of the polyproline (P3) solution, 26.92 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. 9.60 g and 40.0 g of butyl cellosolve gave a liquid crystal alignment agent having a P3 concentration of 6.0% by mass.

[Example 4]

Into a 100 ml four-a beaker equipped with a stirring device and a nitrogen introduction tube, 4.83 g (16.2 mmol) of DA-1 and 1.17 g (10.8 mmol) of DA-2 were placed, and N-methyl-2-pyrrolidone was added thereto. 62.4 g was stirred and dissolved while carrying nitrogen gas. 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 nitrogen was added thereto while stirring. After stirring for 3 hours, 3.30 g (15.1 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred at a water temperature for 20 hours in a nitrogen atmosphere to obtain a polyfluorene. A solution of the amine acid (P4). The viscosity of the polyamic acid (P4) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 288 mPa. s.

To 82.76 g of the polyamic acid (P4) solution, 27.64 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxydecane were added. The N-methyl-2-pyrrolidone solution was 9.60 g and the butyl cellosolve 40.0 g, and a liquid crystal alignment agent having a P4 concentration of 6.0% by mass was obtained.

[Example 5]

1.85 g (6.2 mmol) of DA-1, 1.34 g (12.4 mmol) of DA-2, and 3.55 g (12.4 mmol) of DA-3 were placed in a 100 ml four-a beaker equipped with a stirring device and a nitrogen introduction tube. 64.7 g of N-methyl-2-pyrrolidone was added, and the mixture was stirred and dissolved while carrying nitrogen gas. 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 nitrogen was added while stirring. After stirring for 1 hour, 3.58 g (16.4 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred at a water temperature for 20 hours in a nitrogen atmosphere to obtain a polyfluorene. A solution of aminic acid (P5). The viscosity of the polyamic acid (P5) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 264 mPa. s.

To 84.21 g of the polyproline (P5) solution, 26.19 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. 9.60 g and 40.0 g of butyl cellosolve gave a liquid crystal alignment agent having a P5 concentration of 6.0% by mass.

[Example 6]

Into a 100 ml four-beat beaker equipped with a stirring device and a nitrogen introduction tube, 4.62 g (15.5 mmol) of DA-1 and 1.68 g of DA-2 were placed. (15.5 mmol), 62.9 g of N-methyl-2-pyrrolidone was added, and the mixture was stirred and dissolved while carrying nitrogen gas. 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 nitrogen was added while stirring. After stirring for 1 hour, 5.04 g (23.1 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred at a water temperature for 20 hours in a nitrogen atmosphere to obtain a poly A solution of proline (P6). The viscosity of the polyamic acid (P6) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 262 mPa. s.

To the 84.96 g of the polyaminic acid (P6) solution, 25.44 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g, and 40.0 g of butyl cellosolve, a liquid crystal alignment agent having a P6 concentration of 6.0% by mass was obtained.

[Example 7]

Into a 200 ml four-a beaker equipped with a stirring device and a nitrogen inlet tube, 10.39 g (34.8 mmol) of DA-1 and 2.51 g (23.2 mmol) of DA-2 were added, and N-methyl-2-pyrrolidone was added thereto. 142.9 g was stirred and dissolved while carrying nitrogen gas. 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 nitrogen was added thereto while stirring. After stirring for 2 hours, 7.82 g (35.9 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass. Under a nitrogen atmosphere, the mixture was stirred at a water temperature for 20 hours to obtain a polyfluorene. A solution of aminic acid (P7). The poly The viscosity of the amino acid (P7) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 328 mPa. s.

To the 105.08 g of the polyaminic acid (P7) solution, 42.93 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g and butyl cellosolve 40.0 g, and a liquid crystal alignment agent having a P7 concentration of 6.0% by mass was obtained.

[Example 8]

Into a 200 ml four-a beaker equipped with a stirring device and a nitrogen inlet tube, 4.18 g (14.0 mmol) of DA-1 and 2.10 g (14.0 mmol) of DA-4 were placed, and N-methyl-2-pyrrolidone was added thereto. 70.5 g was stirred and dissolved while carrying nitrogen gas. While stirring the diamine solution, 5.86 g (26.9 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred at a water temperature for 20 hours in a nitrogen atmosphere. A solution of polyamic acid (P8) is then obtained. The viscosity of the polyamic acid (P8) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 311 mPa. s.

To the 55.74 g of the polyaminic acid (P8) solution, 15.61 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g and butyl cellosolve 25.85 g, and a liquid crystal alignment agent having a P8 concentration of 6.0% by mass was obtained.

[Example 9]

In a 200ml four-beat beaker with a stirring device and a nitrogen inlet tube, 7.94 g (28.1 mmol) of CA-5 and 136.5 g of N-methyl-2-pyrrolidone were placed and completely dissolved. Next, 6.16 g of triethylamine, 4.33 g (14.5 mmol) of DA-1, and 2.18 g (14.5 mmol) of DA-4 were added to completely dissolve. Thereafter, the reaction liquid was stirred with a magnetic stirrer while stirring, and 23.35 g of diphenyl(2,3-dihydro-2-thione-3-benzoxazolyl)phosphonate was added (60.9). Additional), 18.75 g of N-methyl-2-pyrrolidone was added and stirring was continued for 5 hours. Thereafter, while stirring 6 times by mass of the isopropyl alcohol of the reaction solution, the reaction solution was slowly poured and stirring was continued for 1 hour. Thereafter, the precipitate obtained by filtration was stirred with 2 times by mass of isopropyl alcohol for 1 hour, and then filtered again to recover the precipitate. Thereafter, the work was repeated twice, and the obtained precipitate was dried at 100 ° C under reduced pressure for 24 hours to obtain 10.54 g of a polyamine (P9). 5.14 g of the obtained solid matter was completely dissolved in 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 alignment agent having a P9 concentration of 4.5% by mass.

[Example 10]

Into a 100 ml four-a beaker equipped with a stirring device and a nitrogen introduction tube, 1.50 g (5.03 mmol) of DA-1 and 5.85 g (20.0 mmol) of DA-7 were placed, and N-methyl-2-pyrrolidone was added thereto. 73 g was stirred and dissolved while carrying nitrogen gas. While stirring the diamine solution, 5.23 g (24.0 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass in a nitrogen atmosphere. The mixture was stirred at a water temperature for 20 hours to obtain a solution of polyglycine (P10). The viscosity of the polyamic acid solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 327 mPa. s.

After adding 15.49 g of N-methyl-2-pyrrolidone and 16.86 g of butyl cellosolve to 35.10 g of the polyamic acid solution, a liquid crystal alignment agent having a P10 concentration of 6.0% by mass was obtained.

[Example 11]

Into a 100 ml four-a beaker equipped with a stirring device and a nitrogen introduction tube, 3.73 g (12.5 mmol) of DA-1 and 3.65 g (12.5 mmol) of DA-7 were placed, and N-methyl-2-pyrrolidone was added thereto. 73 g was stirred and dissolved while carrying nitrogen gas. While stirring the diamine solution, 5.18 g (23.8 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass. Under a nitrogen atmosphere, 20 at a water temperature. After stirring for a while, a solution of polyamic acid (P11) was obtained. The viscosity of the polyamic acid solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 289 mPa. s.

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

[Example 12]

2. In a 100 ml four-beat beaker equipped with a stirring device and a nitrogen introduction tube, 2.21 g (7.41 mmol) of DA-1 and 5.01 g of DA-7 were placed. (17.1 mmol), 73 g of N-methyl-2-pyrrolidone was added, and the mixture was stirred and dissolved while carrying nitrogen gas. While stirring the diamine solution, 5.07 g (23.2 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass. Under a nitrogen atmosphere, the temperature was 20. After stirring for a while, a solution of polyglycine (P12) was obtained. The viscosity of the polyamic acid solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 267 mPa. s.

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

[Example 13]

Into a 100 ml four-a beaker equipped with a stirring device and a nitrogen introduction tube, 1.43 g (4.80 mmol) of DA-1 and 5.61 g (19.2 mmol) of DA-7 were placed, and N-methyl-2-pyrrolidone was added thereto. 79 g was stirred and dissolved while carrying nitrogen gas. While stirring the diamine solution, 6.77 g (23.0 mmol) of CA-6 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass. Under a nitrogen atmosphere, the temperature was 20. After stirring for a while, a solution of polyglycine (P13) was obtained. The viscosity of the polyamic acid solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 240 mPa. s.

To the 14.76 g of the polyaminic acid solution, 7.22 g of N-methyl-2-pyrrolidone and 7.32 g of butyl cellosolve were added to obtain a liquid crystal alignment 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-aluminum beaker equipped with a stirring device and a nitrogen gas introduction tube, and 139.1 g of N-methyl-2-pyrrolidone was added thereto, and the mixture was stirred while carrying nitrogen gas. Dissolved. 12.91 g (59.2 mmol) of CA-1 was added to the diamine solution while stirring under water cooling, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and under a nitrogen atmosphere at 50 degrees. After heating for 20 hours while heating, a solution of polyamic acid (A1) was obtained. The viscosity of the polyamic acid (A1) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 530 mPa. s.

To the 50.00 g of the polyaminic acid (A1) solution, 43.95 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g. and 24.89 g of butyl cellosolve gave a liquid crystal alignment agent having a concentration of A1 of 4.5% by mass.

[Comparative Example 2]

Into a 200 ml four-beat beaker equipped with a stirring device and a nitrogen inlet tube, 3.25 g (30.0 mmol) of DA-2 and 8.60 g (30.0 mmol) of DA-3 were placed, and N-methyl-2-pyrrolidone was added thereto. 138.1 g was stirred and dissolved while carrying nitrogen gas. 12.59 g (57.7 mmol) of CA-1 was added to the diamine solution while stirring under water cooling, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred for 20 hours in a nitrogen atmosphere. Getting polylysine (A2) dissolved liquid. The viscosity of the polyamic acid (A2) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 310 mPa. s.

To the 52.34 g of the polyaminic acid (A2) solution, 23.18 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g. and 27.17 g of butyl cellosolve gave a liquid crystal alignment agent having a concentration of A2 of 5.5% by mass.

[Comparative Example 3]

7.4 g (25.6 mmol) of DA-1 and 4.15 g (38.4 mmol) of DA-2 were placed in a 200 ml four-beat beaker equipped with a stirring device and a nitrogen introduction tube, and N-methyl-2-pyrrolidone was added thereto. 141.6 g was stirred and dissolved while carrying nitrogen gas. The diamine solution was added with 6.81 g (34.7 mmol) of CA-2 and 35.4 g of N-methyl-2-pyrrolidone while stirring under water cooling, and the mixture was stirred while feeding nitrogen. After stirring for 2 hours, 5.58 g (25.6 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred for 20 hours in a nitrogen atmosphere to obtain polylysine ( A3) solution. The viscosity of the polyamic acid (A3) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 276 mPa. s.

To the 53.33 g of the polyaminic acid (A3) solution, 22.01 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were dissolved in a solution of 6.12 g. g and butyl cellosolve 20.35 g, and a liquid crystal alignment agent having a concentration of A3 of 6.0% by mass was obtained.

[Comparative Example 4]

Into a 100 ml four-a beaker equipped with a stirring device and a nitrogen introduction tube, 3.14 g (10.5 mmol) of DA-1 and 2.64 g (24.4 mmol) of DA-2 were placed, and N-methyl-2-pyrrolidone was added thereto. 71.6 g was stirred and dissolved while carrying nitrogen gas. After the diamine solution was stirred under water cooling, 6.55 g (33.4 mmol) of CA-2 was added thereto, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred for 20 hours in a nitrogen atmosphere. A solution of polyamic acid (A4) was obtained. The viscosity of the polyamic acid (A4) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 274 mPa. s.

To the 20.09 g of the polyaminic acid (A4) solution, 8.64 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g and 4.7 cellosolve of butyl cellosolve gave a liquid crystal alignment agent having a concentration of A4 of 6.0% by mass.

[Comparative Example 5]

0.81 g (28 mmol) of DA-1, 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-a beaker equipped with a stirring device and a nitrogen introduction tube. Then, 72.6 g of N-methyl-2-pyrrolidone was added, and the mixture was stirred and dissolved while carrying nitrogen gas. 2.67 g (10.1 mmol) of CA-3 was added to the diamine solution while stirring under water cooling. After stirring for 2 hours, 3.66 g (16.8 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was further added until the solid content concentration became 12% by mass, and the mixture was stirred for 20 hours in a nitrogen atmosphere. A solution of polyamic acid (A5). The viscosity of the polyamic acid (A5) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 358 mPa. s.

To the 50.59 g of the polyaminic acid (A5) solution, 14.51 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g. and 23.59 g of butyl cellosolve gave a liquid crystal alignment agent having a concentration of A5 of 6.0% by mass.

[Comparative Example 6]

7.97 g (40.0 mmol) of DA-6 and 98.6 g of N-methyl-2-pyrrolidone were placed in a 200 ml four-aluminum beaker equipped with a stirring device and a nitrogen introduction tube, and the mixture was stirred and dissolved while carrying nitrogen gas. . To the diamine solution, 6.96 g (35.5 mmol) of CA-2 and 35.9 g of N-methyl-2-pyrrolidone were added while stirring under water cooling, and the mixture was stirred under water cooling 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 the mixture was stirred and dissolved. After dissolving DA-5, 3.00 g (10.0 mmol) of CA-4 and 26.9 g of N-methyl-2-pyrrolidone were added, and the mixture was stirred under nitrogen for 3 hours under water to obtain polylysine (A6). Solution. The viscosity of the polyamic acid (A6) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to obtain 165 mPa. s.

To the 50.00 g of the polyaminic acid (A6) solution, 10.55 g of N-methyl-2-pyrrolidone and 1.0% by mass of N-methyl-2-pyrrolidone containing 3-aminopropyltriethoxydecane were added. g, and butyl cellosolve 16.37g, A solution having a concentration of 6.0% by mass to A6.

Further, 24.67 g of N-methyl-2-pyrrolidone and 18.66 g of butyl cellosolve were added to 50.00 g of a polyamine acid solution of A1 to obtain a liquid crystal alignment agent having a concentration of A1 of 6.0% by mass. The two 6.0% by mass solutions were mixed in a ratio of A1:A6 of 2:8 to obtain a polyamic acid solution A7.

Using the liquid crystal alignment agents obtained in Examples 2 to 13 and Comparative Examples 1 to 6, an evaluation sample such as a film or a liquid crystal cell was prepared in the same manner as in Example 1, and scratch resistance, visual transmittance evaluation, and afterimage evaluation were performed. And afterimage evaluation caused by long-term driving. The results obtained are shown in Table 3.

In the film formed using the liquid crystal alignment agents of Examples 1 to 13, the rubbing resistance was good and the transmittance was also good. Further, when it is applied to the liquid crystal alignment film in the evaluation of the liquid crystal cell, there is no temperature dependence of the afterimage evaluation, and the afterimage evaluation result by long-term driving is also good.

On the other hand, in the liquid crystal alignment film formed using the liquid crystal alignment agents of Comparative Examples 1 to 6, it was difficult to provide both afterimage characteristics, high transmittance, and rub resistance, and it was found that all the items could not be made good. Comparative Example 1 and Comparative Example 2 in which DA-1 was not used as the diamine component, and Comparative Example 5 in which DA-1 was used as the diamine component was found to have poor rubbing resistance.

In Comparative Example 4 in which the tetracarboxylic acid derivative component was not used for CA-1 and Comparative Example 3 in which the amount of introduction was small, the afterimage at 23 ° C was returned to be poor, and Comparative Example 4 was found to be responsible for evaluation of afterimage caused by long-term driving. The result is also bad.

Further, in Comparative Example 6 in which DA-1 was not used, it was found that high visual transmittance was not obtained.

[Industrial Applicability]

By using the liquid crystal alignment agent of the present invention, a liquid crystal alignment film which has high transmittance, excellent rub resistance, and display defects such as afterimages which can be improved over a wide temperature range can be obtained. The liquid crystal alignment film can be used for a large-sized liquid crystal television that has been required to have high display quality in the past, or a liquid crystal display device for a mobile phone or a flat type device that has been rapidly required to have improved display quality in recent years.

The entire contents of the specification, the scope of the application, and the abstract of Japanese Patent Application No. 2011-235976, filed on Jan. 27, 2011, are hereby incorporated by reference.

Claims (8)

A liquid crystal alignment agent which is a liquid crystal alignment agent containing a polyimine precursor obtained by reacting a diamine component and a tetracarboxylic acid derivative, wherein the diamine component contains 20 mol% or more and 100 mol% or less. a diamine compound represented by the following formula (1), wherein the tetracarboxylic acid derivative is an aromatic tetracarboxylic acid derivative containing 50 mol% or more and less than 100 mol%, or the foregoing two The amine component is a diamine compound represented by the following formula (1) in an amount of 20 mol% or more and less than 100 mol%, and the tetracarboxylic acid derivative contains 50 mol% or more and 100 mol% or less. a content of an aromatic tetracarboxylic acid derivative; (In the formula (1), X is an oxygen atom or a sulfur atom, and Y ¹ and Y ^{2 are} independently a single bond, -O-, -S-, -OCO-, or COO-, and R ¹ and R ^{2 are} independently a carbon number. 1 to 3 alkyl groups). The liquid crystal alignment agent of claim 1, wherein the diamine component further contains a diamine compound represented by the following formula (AM1); (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 base) The liquid crystal alignment agent of claim 2, wherein, in the diamine compound represented by the above formula (AM1), R ⁵ is selected from the group consisting of the above formula (a-1), formula (a-4), and formula (a-). 5) A diamine compound having one structure grouped in the formula (a-6), the formula (a-10), the formula (a-16), the formula (a-19), and the formula (a-20). The liquid crystal alignment agent according to any one of the items 1 to 3, wherein the diamine component is contained in the above formula (1) in an amount of 50 mol% or more and less than 100 mol%. Amine compound. The liquid crystal alignment agent according to any one of the items 1 to 4, wherein the tetracarboxylic acid derivative is a compound selected from the group consisting of the following formula (2-a) to formula (2-e). a group of more than one compound; (In the formula (2-a) to the formula (2-e), R ⁷ represents an alkyl group, and R ⁶ represents a structure having a group selected from the group consisting of the following formulas (b-1) to (b-8). 4-valent organic base) The liquid crystal alignment agent of claim 5, wherein the tetracarboxylic acid derivative is a compound represented by the above formula (2-a). A liquid crystal alignment film characterized by being obtained from a liquid crystal alignment agent according to any one of claims 1 to 6. A liquid crystal display element characterized by having a liquid crystal alignment film according to item 7 of the patent application.