KR20230048163A - 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 aligning film, and a liquid crystal display element capable of forming a liquid crystal aligning film having high transmittance and rubbing resistance and having improved display defects in a wide temperature range.
Obtained by reacting a diamine containing the diamine of formula (1) in an amount of 20 mol% or more and 100 mol% or less, and a tetracarboxylic acid derivative containing an aromatic tetracarboxylic acid derivative in an amount of 50 mol% or more and less than 100 mol% A polyimide precursor or diamine containing 20 mol% or more and less than 100 mol% of the diamine of formula (1) and a tetracarboxylic acid derivative containing 50 mol% or more and 100 mol% or less of an aromatic tetracarboxylic acid derivative The liquid crystal aligning agent containing the polyimide precursor obtained by making it react.

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

Description

Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element {LIQUID CRYSTAL ALIGNING AGENT, LIQUID CRYSTAL ALIGNMENT FILM, AND LIQUID CRYSTAL DISPLAY ELEMENT}

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

A liquid crystal alignment film is a film for controlling the alignment direction of liquid crystal molecules to be constant in a liquid crystal display device or a retardation plate using a polymerizable liquid crystal. A liquid crystal alignment film becomes a very important structural member together with a liquid crystal etc. in a liquid crystal display element etc.

In recent years, in the field of a more advanced liquid crystal display element, heat resistance, solvent resistance, etc. are requested|required of a liquid crystal aligning film in addition to the performance (henceforth liquid-crystal orientation also called) which controls the orientation of a liquid crystal. In addition, various other characteristics are required so that the liquid crystal display element can exhibit high performance.

As one of the properties required for a liquid crystal alignment film, there is a property related to improvement in display quality of a liquid crystal display element. For example, in a liquid crystal display element, improvement of display defect is calculated|required, and the improvement of liquid crystal aligning film characteristic is calculated|required as a countermeasure against display defect.

In particular, in mobile phones and tablet-type terminals, which are rapidly becoming highly precise in recent years, high display quality is required even for liquid crystal display elements used. As a result, specifications for display defects called "afterimages" or simply "afterimages" are becoming stricter. For example, even if an afterimage occurs, realization of a liquid crystal aligning film having a characteristic of quickly disappearing it is required. In recent liquid crystal display elements, since the use environment does not stay indoors, high quality performance is required even in high-temperature places such as outdoors and in cars, and a liquid crystal alignment film whose afterimage characteristics do not change at room temperature and high temperature is required.

Further, in mobile terminals such as cell phones, low power consumption of liquid crystal display elements is required. In such a portable terminal, it is possible to use the device for a long period of time by charging the battery once due to the low power consumption of the liquid crystal display element. High transmittance of a liquid crystal display element is effective for low power consumption of a liquid crystal display element. Therefore, in a liquid crystal display element, the improvement of the transmittance|permeability is calculated|required with respect to structural members, such as a liquid crystal aligning film, with the high aperture ratio of a pixel.

Moreover, the high tolerance with respect to a rubbing process is calculated|required of a liquid crystal aligning film from an applicability viewpoint with respect to the manufacturing process of a liquid crystal display element. A rubbing process is known as a method of forming a liquid crystal aligning film in the manufacturing process of a liquid crystal display element, and is still widely used industrially. In the rubbing treatment, a polymer film such as polyimide is formed on a substrate, and alignment treatment is performed by rubbing the surface with a cloth.

In the rubbing treatment, there is a problem that dust generated when the liquid crystal aligning film is scraped off or scratches generated on the liquid crystal aligning film deteriorate display quality. Therefore, resistance (henceforth rubbing resistance) with respect to a rubbing process is calculated|required of the liquid crystal aligning film.

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

In addition, polyimide structures having good rubbing resistance and the like have been proposed (for example, see Patent Literatures 3 and 4).

By such a method, it is possible to make it difficult to generate scratches (also referred to as rubbing scratches) and flaws (also referred to as rubbing flaws) of the liquid crystal aligning film at the time of the rubbing treatment.

However, in recent years, in some applications of liquid crystal display elements, in rubbing treatment, there is a tendency to more strongly rub polymer films such as polyimide with a cloth to perform alignment treatment. Such a strong rubbing treatment is based on the objective of making the alignment state of liquid crystals more uniform and more robust. Therefore, the rubbing tolerance of a higher level is requested|required with respect to a liquid crystal aligning film.

Japanese Unexamined Patent Publication No. 7-120769 Japanese Unexamined Patent Publication No. 9-146100 Japanese Unexamined Patent Publication No. 2008-90297 Japanese Unexamined Patent Publication No. 9-258229

An object of the present invention is to provide a liquid crystal aligning agent that has high liquid crystal orientation and rubbing resistance, is effective for reducing afterimage in a wide temperature range in a liquid crystal display element, and can form a liquid crystal alignment film with high light transmittance.

Moreover, the objective of this invention has high liquid-crystal orientation property and rubbing resistance using the liquid crystal aligning agent as mentioned above, and is effective for the afterimage reduction in a wide temperature range in a liquid crystal display element, and the liquid crystal aligning film of a high light transmittance is to provide Moreover, it is providing the liquid crystal display element which has this liquid crystal aligning film.

The present inventors came to complete this invention, as a result of repeating earnest examination in order to solve the said subject.

That is, this invention has the following summary.

(1) As a liquid crystal aligning agent containing a polyimide precursor obtained by making a diamine component and a tetracarboxylic acid derivative react,

The diamine component contains the diamine compound represented by the following formula (1) in an amount of 20 mol% or more and 100 mol% or less, and the tetracarboxylic acid derivative contains an aromatic tetracarboxylic acid derivative of 50 mol% or more and less than 100 mol%. content, or the diamine component contains 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 an aromatic tetracarboxylic acid derivative of 50 mol% or more The liquid crystal aligning agent characterized by containing in content of 100 mol% or less.

[Formula 1]

(In Formula (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 as described in said (1) in which the said diamine component further contains the diamine compound represented by following formula (AM1).

[Formula 2]

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

[Formula 3]

(3) As for the diamine compound represented by said formula (AM1), ^R5 is said formula (a-1), formula (a-4), formula (a-5), formula (a-6), formula (a) -10), the formula (a-16), the formula (a-19) and the liquid crystal aligning agent as described in said (2) which is a diamine compound which has one structure chosen from the group which consists of a formula (a-20).

(4) The liquid crystal aligning agent as described in any one of said (1)-(3) in which the said diamine component contains the diamine compound represented by said Formula (1) by content of 50 mol% or more and less than 100 mol%.

(5) The tetracarboxylic acid derivative is one or more compounds selected from the group consisting of compounds represented by the following formulas (2-a) to (2-e), in any one of (1) to (4) The liquid crystal aligning agent described.

[Formula 4]

(In the formulas (2-a) to (2-e), R ⁷ represents an alkyl group, and R ⁶ is one structure selected from the group consisting of the following formulas (b-1) to (b-8)) Represents a tetravalent organic group having)

[Formula 5]

(6) The liquid crystal aligning agent as described in said (5) whose said tetracarboxylic acid derivative is said formula (2-a).

(7) The liquid crystal aligning film obtained from the liquid crystal aligning agent in any one of said (1)-(6).

(8) The liquid crystal display element characterized by having the liquid crystal aligning film as described in said (7).

This invention has high liquid-crystal orientation and rubbing resistance, is effective for the afterimage reduction in a liquid crystal display element, and can provide the liquid crystal aligning agent which can form the liquid crystal aligning film of high light transmittance.

Moreover, this invention can provide the liquid crystal aligning film of high light transmittance which has high liquid-crystal orientation property and rubbing resistance, and is effective for the afterimage reduction in a liquid crystal display element using the said liquid crystal aligning agent.

Moreover, this invention can provide the liquid crystal display element using the liquid crystal aligning film which has the above characteristics.

The liquid crystal aligning agent of this invention contains the polyimide precursor obtained by making a diamine component and a tetracarboxylic acid derivative react. Examples of the polyimide precursor include polyamic acid and polyamic acid ester.

The polyimide precursor contained in the liquid crystal aligning agent of the present invention is formed using a diamine component having a characteristic structure and a tetracarboxylic acid derivative suitable for realization of desired characteristics by a combination of the diamine component.

Hereinafter, the diamine component, tetracarboxylic acid derivative, etc. used in order to obtain the polyimide precursor contained in the liquid crystal aligning agent of this invention are demonstrated in detail.

<Specific diamine compound (1)>

The liquid crystal aligning agent of this invention uses the specific diamine compound of the specific structure represented by following formula (1) as a diamine component for obtaining polyimide precursors, such as a polyamic acid and polyamic acid ester, to be contained.

[Formula 6]

In the formula (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 It is an alkylene group of 1-3 carbon atoms independently.

When X in the formula (1) is an oxygen atom, the specific diamine compound of the formula (1) is a diamine compound having a urea group, and when X is a sulfur atom, a thiourea group (hereinafter referred to as a urea group and a thiourea group) It is a diamine compound having a urea group (sometimes collectively referred to as a (thio)urea group).

As a preferable example of the diamine compound represented by said Formula (1), the compound of a following formula is mentioned. Especially, the compound represented by Formula (1-1), Formula (1-5) - Formula (1-8) is preferable.

[Formula 7]

Although the diamine component for obtaining the polyimide precursor contained in the liquid crystal aligning agent of this invention contains the specific diamine compound of said Formula (1) as an essential component, it can be set as arbitrary values as content of the specific diamine compound contained. .

In order for the liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention to acquire sufficient rubbing resistance, it is preferable that the specific diamine compound of said Formula (1) is 20 mol% or more in all the diamine components (100 mol%), and more preferable. Preferably it is 30 mol% or more, and more preferably 50 mol% or more.

Moreover, from viewpoints of optimization of the pretilt angle of the liquid crystal at the time of forming a polyimide from the polyimide precursor contained in a liquid crystal aligning agent, and applying to a liquid crystal display element as a liquid crystal aligning film, reduction of stored electric charge, etc., the said formula (1 ) It is preferable that content of the specific diamine compound represented by is less than 100 mol% of all diamine components, More preferably, it is 30 to 60%.

When content of the specific diamine compound represented by the said formula (1) is 100 mol% in all diamine components, that is, when all diamine components are the specific diamine compounds represented by the said formula (1), as mentioned later, a polyimide precursor The content of the aromatic tetracarboxylic acid derivative in the tetracarboxylic acid derivative used for the formation of is 50 mol% or more and less than 100 mol% based on all tetracarboxylic acid components. Therefore, in the liquid crystal aligning agent of this invention, while all diamine components are the specific diamine compound of said Formula (1), all tetracarboxylic acid derivatives are not aromatic tetracarboxylic acid derivatives.

<diamine compound (AM1)>

The polyimide precursor contained in the liquid crystal aligning agent of this invention is obtained by reaction of the diamine component and tetracarboxylic acid derivative which contain the specific diamine compound represented by said Formula (1) as an essential component.

Moreover, the diamine component for obtaining the polyimide precursor of this invention uses together the diamine compound represented by the following formula (AM1) together with the specific diamine compound represented by said formula (1), and reacts with a tetracarboxylic acid derivative. It is preferable to use

[Formula 8]

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

[Formula 9]

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

Moreover, the diamine component for obtaining the polyimide precursor contained in the liquid crystal aligning agent of this invention makes the specific diamine compound of said Formula (1) an essential component, and can contain the diamine compound represented by said formula (AM1) However, it is also possible to further contain diamine compounds other than those.

That is, the diamine component for obtaining the polyimide precursor contained in the liquid crystal aligning agent of the present invention is a specific diamine compound of the above formula (1) and a diamine compound of the above formula (AM1) within a range that does not impair the effect of the present invention. It is also possible to contain other diamine compounds.

<Tetracarboxylic acid derivative>

The tetracarboxylic acid derivative which can be used in order to obtain the polyimide precursor contained in the liquid crystal aligning agent of this invention is not specifically limited.

As a tetracarboxylic acid derivative of this invention, tetracarboxylic dianhydride (represented by the following formula (2-a)), tetracarboxylic acid 1 anhydride (represented by the following formula (2-b)), tetracarboxylic Acid (represented by the following formula (2-d)), dicarboxylic acid dialkyl ester (represented by the following formula (2-c)), dicarboxylic acid chloride dialkyl ester (represented by the following formula (2-e)) etc. can be mentioned. The tetracarboxylic acid derivative is not limited to these as long as the reaction with diamine proceeds.

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

Here, R ⁷ represents an alkyl group.

Moreover, as a specific example of R ^<6> , the following formula [A-1] - formula [A-47] are mentioned.

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

As a tetracarboxylic acid derivative which can be used in order to obtain the polyimide precursor contained in the liquid crystal aligning agent of this invention, use of an aromatic tetracarboxylic acid derivative is especially preferable. It is also possible to make all the tetracarboxylic acid derivatives aromatic tetracarboxylic acid derivatives.

In order to obtain the said polyimide precursor, it is possible to use for reaction with a diamine component using 2 or more types of tetracarboxylic acid derivatives. Also in that case, it is preferable to use one or more types of aromatic tetracarboxylic acid derivatives contained in the tetracarboxylic acid derivative.

Moreover, it is possible to use all the tetracarboxylic acid derivatives as aromatic tetracarboxylic acid derivatives, and to use two or more types of aromatic tetracarboxylic acid derivatives having different structures.

By containing an aromatic tetracarboxylic acid derivative as a tetracarboxylic acid derivative, it becomes possible to improve the liquid-crystal orientation of the liquid crystal aligning film obtained by being used for formation of a polyimide precursor. At this time, it is preferable that the content of the aromatic tetracarboxylic acid derivative is 50 mol% or more with respect to the total amount of the tetracarboxylic acid derivative used. However, when all the diamine components used for formation of the polyimide precursor are diamine compounds represented by the formula (1), as described above, the content of the aromatic tetracarboxylic acid derivative is the total amount of the tetracarboxylic acid derivative used. less than 100 mol% relative to the amount.

As an aromatic tetracarboxylic acid derivative preferably used in order to obtain a polyimide precursor contained in the liquid crystal aligning agent of the present invention, selected from the group consisting of compounds represented by the formulas (2-a) to (2-e) is one or more compounds, wherein R ⁷ is an alkyl group, and R ⁶ represents a tetravalent organic group having a structure selected from the group consisting of the following formulas (b-1) to (b-8) A boxylic acid derivative is mentioned.

[Formula 15]

In the aromatic tetracarboxylic acid derivative having a structure represented by the formulas (2-a) to (2-e) and R ⁶ represented by the formula (b-1), the specific example of R ⁶ described above is the formula [ A-26] corresponds to a tetracarboxylic acid derivative.

Similarly, the aromatic tetracarboxylic acid derivative having a structure in which R ⁶ is represented by the formula (b-2) corresponds to a tetracarboxylic acid derivative in which the specific example of R ⁶ is the formula [A-27].

The aromatic tetracarboxylic acid derivative having a structure represented by the formula (b-3) in which R ⁶ corresponds to a tetracarboxylic acid derivative in which the specific example of R ⁶ is the formula [A-28].

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

The aromatic tetracarboxylic acid derivative having a structure in which R ⁶ is represented by the formula (b-5) 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 in which R ⁶ is represented by the formula (b-6) corresponds to a tetracarboxylic acid derivative in which the specific example of R ⁶ is the formula [A-30].

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

The aromatic tetracarboxylic acid derivative having a structure in which R ⁶ is represented by the formula (b-8) corresponds to a tetracarboxylic acid derivative in which the specific example of R ⁶ is the formula [A-47].

In order to obtain the polyimide precursor contained in the liquid crystal aligning agent of this invention, as an aromatic tetracarboxylic acid derivative especially preferable to use, in the group which consists of compounds represented by the said formula (2-a) - formula (2-e) aromatic tetracarboxylic acid derivatives having structures represented by the above formulas (b-1), (b-2) and (b-7), wherein R ⁷ is an alkyl group, and R ⁶ is one or more selected compounds. can

<Polyimide precursor>

A well-known method can be used as a method of obtaining the polyimide precursor contained in the liquid crystal aligning agent of this invention.

A 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.

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

The polymerization reaction method of the diamine component and tetracarboxylic acid derivative used for manufacture of the polyimide precursor contained in the liquid crystal aligning agent of this invention is not specifically limited. A polymerization reaction can be carried out by mixing them in an organic solvent, and it can be set as polyamic acid which is a polyimide precursor. Moreover, a polyamic acid ester can be obtained by esterifying a carboxylic acid group of a polyamic acid using a known esterifying agent. A polyimide can be obtained by dehydrating and cyclizing the obtained polyamic acid and polyamic acid ester.

As a method of mixing the diamine component and the tetracarboxylic acid derivative in an organic solvent, a method in which a solution in which the diamine component is dispersed or dissolved in an organic solvent is stirred and the tetracarboxylic acid derivative component is added as it is, or a method in which the tetracarboxylic acid derivative component is added as it is A method of adding a derivative component by dispersing or dissolving it in an organic solvent is exemplified.

In addition, a method of adding a diamine component to a solution obtained by dispersing or dissolving a tetracarboxylic acid derivative in an organic solvent, a method of adding a tetracarboxylic acid derivative and diamine alternately, and the like are exemplified. Moreover, when at least one of the tetracarboxylic acid derivative component and diamine consists of multiple types of compounds, polymerization may be carried out in the state where these multiple types of components were previously mixed, or you may carry out sequential polymerization reaction individually.

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. The higher the temperature, the faster the polymerization reaction ends. However, when the temperature is too high, a high molecular weight polymer may not be obtained. In addition, the polymerization reaction can be carried out at any injection concentration, but if the injection concentration is too low, it is difficult to obtain a high molecular weight polymer, and if the injection concentration is too high, the viscosity of the reaction solution becomes too high, making uniform stirring difficult. Preferably it is 1-50 mass %, More preferably, it is 5-30 mass %. The initial stage of the polymerization reaction may be performed at a high concentration, and then an organic solvent may be added. In addition, the injection|pouring concentration mentioned above is the density|concentration of the total mass which combined the diamine component and the tetracarboxylic acid derivative.

The organic solvent used in the polymerization reaction described above is not particularly limited as long as it dissolves the polyamic acid and polyamic acid ester (hereinafter sometimes referred to as polyamic acid (ester)). Specific examples include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexane Methyl sulfoxide, γ-butyrolactone, etc. are mentioned. These may be used alone or in mixture. In addition, even if it is a solvent that does not dissolve the polyamic acid (ester), you may mix it with the said solvent and use it within the range in which the polyamic acid (ester) produced|generated does not precipitate.

In addition, since moisture in the organic solvent inhibits the polymerization reaction and causes hydrolysis of the polyamic acid (ester) produced, it is preferable to use a dehydrated organic solvent as much as possible.

The ratio of the tetracarboxylic acid derivative and the diamine used in the polymerization reaction to obtain the polyamic acid is preferably from 1:0.8 to 1:1.2 in terms of molar ratio, and the closer this molar ratio is to 1:1, the higher the molecular weight of the polyamic acid obtained. gets bigger When the molecular weight of the polyamic acid (ester) is too small, the strength of the obtained coating film may be insufficient, and conversely, when the molecular weight of the polyamic acid (ester) is too large, the viscosity of the obtained liquid crystal aligning agent becomes too high, and at the time of coating film formation Workability, uniformity of the coating film, and the like may deteriorate. Therefore, as for the weight average molecular weight of the polyamic acid (ester) used for the liquid crystal aligning agent of this invention, 2,000-500,000 are preferable, More preferably, they are 5,000-300,000.

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

Moreover, as a diamine component, in addition to the specific diamine compound represented by the said formula (1), the diamine component containing the diamine compound represented by the said formula (AM1) and the diamine component containing the diamine compound other than those further are used. do.

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

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

Moreover, polyamic acid ester can be represented by following formula (4).

[Formula 16]

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

When the specific diamine compound represented by said 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 the diamine compound represented by the 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 derivatives represented by the above formulas (2-a) to (2-e).

R in Formula (4) is a group derived from the esterification agent used.

The polyamic acid or polyamic acid ester obtained by the above can be used for the liquid crystal aligning agent of this invention as it is. Moreover, it is also possible to make the liquid crystal aligning agent of this invention contain the polyimide which carried out the dehydration ring closure of the polyamic acid or polyamic acid ester obtained by the above.

<liquid crystal aligning agent>

The liquid crystal aligning agent of this invention contains the polyimide precursor obtained by doing it above, and can usually be made into the coating liquid which melt|dissolved these polymers in the organic solvent.

The liquid crystal aligning agent of this invention may contain the polyimide obtained from the polyimide precursor other than the polyimide precursor mentioned above, and the polymer which has other structures.

1-20 mass % is preferable with respect to the whole amount of liquid crystal aligning agents, and, as for content of the polyimide precursor in the liquid crystal aligning agent of this invention, 2-20 mass % is more preferable.

The organic solvent contained in the liquid crystal aligning agent of this invention will not be specifically limited if it dissolves the contained polymer.

80-99 mass % is preferable with respect to the whole amount of liquid crystal aligning agents, and, as for the usage-amount of an organic solvent, 80-98 mass % is more preferable.

As specific examples of the organic solvent used for the liquid crystal aligning agent of the present invention, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2 -pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 1,3-dimethyl-imine Dazolidinone etc. are mentioned. You may use these 1 type or in mixture of 2 or more types.

Moreover, even if it is independent, even if it is a solvent which does not dissolve polymers, such as a polyimide precursor or a polyimide, it can mix with the liquid crystal aligning agent of this invention as long as it is the range in which a polymer does not precipitate.

In particular, 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, Solvents with low surface tension, such as dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, ethyl lactate, N-propyl lactate, N-butyl lactate, isoamyl lactate, etc. , The coating film uniformity with respect to the board|substrate of a liquid crystal aligning agent can be improved by mixing. In the case of using these solvents, one type may be used, or multiple types may be mixed and used.

Also in the liquid crystal aligning agent of the present invention, a solvent having low surface tension is preferably used, but the amount used is more preferably 5 to 80% by mass of the entire solvent contained in the liquid crystal aligning agent, still more preferably 20 to It is 60 mass %.

The liquid crystal aligning agent of this invention may contain various additives other than polymers, such as said polyimide precursor and polyimide, and organic solvent, within the range which does not impair the effect of this invention.

The liquid crystal aligning agent of this invention can contain the additive which improves the film thickness uniformity and surface smoothness of the liquid crystal aligning film formed. Examples of such additives include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

More specifically, for example, Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megafac F171, F173, R-30 (manufactured by Dainippon Ink Co., Ltd.), Florado FC430, FC431 (manufactured by Sumitomo 3M) manufacture), Asahi Guard AG710, Suffron S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), and the like. The usage ratio of these surfactants is preferably from 0.01 to 2 parts by mass, more preferably from 0.01 to 1 part by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

The liquid crystal aligning agent of this invention can contain the additive which improves the adhesiveness of the formed liquid crystal aligning film and a board|substrate. Specific examples of such additives include functional silane-containing compounds and epoxy group-containing compounds.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3 -Aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxy Carbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine 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-phenyl-3- Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltri Ethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol di Glycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglyceride Cydyl-2,4-hexanediol, N,N,N',N',-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclo Hexane, N,N,N',N',-tetraglycidyl-4,4'-diaminodiphenylmethane, etc. are mentioned.

When adding these compounds, it is preferable that it is 0.1-30 mass parts with respect to 100 mass parts of the polymer components contained in a liquid crystal aligning agent, More preferably, it is 1-20 mass parts. The effect of an adhesive improvement cannot be expected as it is less than 0.1 mass part, and when it exceeds 30 mass parts, the liquid-crystal orientation of the liquid crystal aligning film formed may fall.

In addition to the additives described above, in the liquid crystal aligning agent of the present invention, as long as the effect of the present invention is not impaired, polymer components other than polymers, dielectrics or conductive materials for the purpose of changing electrical properties such as dielectric constant and conductivity of the liquid crystal aligning film And, by extension, a crosslinkable compound for the purpose of enhancing the hardness and density of the film when it is used as a liquid crystal aligning film, and the like can be added.

The density|concentration of the solid content in the liquid crystal aligning agent of this invention can be suitably changed according to the film thickness of the liquid crystal aligning film made into the objective. In addition, the concentration of the polymer is preferably 1 to 20% by mass, more preferably 2 to 10% by mass so that a coating film without defects can be formed and a film thickness suitable as a liquid crystal aligning film can be obtained.

Moreover, in the liquid crystal aligning agent of this invention, it is also possible to blend and contain the soluble polyimide which consists of a different molecular structure, polyamic acid, polyamic acid ester, etc. with the polyimide precursor mentioned above. In that case, considering that the obtained polyimide film has the desired characteristics, the total amount (100 mol%) is preferably 5 to 95 mol%, more preferably 10 to 90 mol%.

The liquid crystal aligning agent of the present invention is applied on a substrate to form a coating film, baked, and then subjected to alignment treatment by rubbing treatment, light irradiation, etc., and used as a liquid crystal alignment film, or in vertical alignment applications, liquid crystal without orientation treatment. It can be used as an alignment film.

The substrate 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 may be used, and it is preferable to use a substrate having an indium tin oxide (ITO) electrode for driving the liquid crystal from the viewpoint of simplifying the process. . Moreover, when constituting a reflection type liquid crystal display element, even an opaque material, such as a silicon wafer, can be used only for the board|substrate on one side. As the electrode in this case, a material that reflects light such as aluminum can also be used.

Although the application|coating method of a liquid crystal aligning agent is not specifically limited, Industrially, application methods, such as screen printing, offset printing, flexographic printing, and inkjet, are applicable. As other coating methods, there is a coating method using a dip, roll coater, slit coater, spinner, or the like, and it is possible to use these depending on the purpose.

Baking of the board|substrate to which the liquid crystal aligning agent was apply|coated can be performed at arbitrary temperature of 100-350 degreeC, Preferably it is 150-300 degreeC, More preferably, it is 180-250 degreeC.

When a polyamic acid or polyamic acid ester is contained in the liquid crystal aligning agent, the conversion ratio with respect to polyimide changes according to this firing temperature, but the liquid crystal aligning agent of the present invention does not necessarily need to be imidized 100%.

In addition, the baking time of the coating film of a liquid crystal aligning agent can be set to arbitrary time. If the baking time is too short, display defects may occur due to the influence of residual solvent, so it is preferably 5 to 60 minutes, more preferably 10 to 40 minutes.

When the thickness of the coating film after baking is too thick, it becomes disadvantageous in terms of power consumption of the liquid crystal display element, and when it is too thin, the reliability of the liquid crystal display element may decrease. Therefore, the thickness of the coating film is preferably 5 to 300 nm, more preferably 10 to 100 nm.

When horizontally aligning or diagonally aligning a liquid crystal, it is preferable to align the coating film after baking by rubbing, polarized-light ultraviolet irradiation, etc.

<Liquid crystal display element>

The liquid crystal display element of the present invention uses a substrate with electrodes, etc., and obtains a substrate with a liquid crystal aligning film from the liquid crystal aligning agent of the present invention by the above method, and then prepares a liquid crystal cell by a known method, It can be comprised as a liquid crystal display element.

About the manufacturing method of a liquid crystal cell, it can be set as follows, for example.

A pair of substrates having electrodes or the like for driving liquid crystals formed on at least one of them are prepared. The liquid crystal aligning film of this invention is formed on this pair of board|substrate, and a pair of board|substrate on which the liquid crystal aligning film was formed is prepared. Next, a spacer is spread|dispersed on the liquid crystal aligning film of one board|substrate, the liquid crystal aligning film surface turns inside, the other board|substrate is bonded together, and a liquid crystal is injected under pressure and sealed. In this way, a liquid crystal display element is manufactured.

Moreover, after preparing a pair of board|substrates on which the liquid crystal aligning film of this invention was formed, liquid crystal is dripped on the surface of the liquid crystal aligning film with the spacer spread|dispersed, and then these board|substrates are bonded and sealed, and a liquid crystal display element is manufactured. In these cases, the thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

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

Example

Below, the present invention will be described more specifically by way of Examples and Comparative Examples, but the present invention is not construed as being limited to these Examples.

Abbreviations used in Examples and Comparative Examples are as follows.

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

DA-2: paraphenylenediamine

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 dianhydride

CA-2: 1,2,3,4-cyclobutanetetracarboxylic 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 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 pipe, and N-methyl-2-pyrrolidone was added. 141 g was added and dissolved by stirring while blowing nitrogen. Then, 12.82 g (58.7 mmol) of CA-1 was added while stirring this diamine solution, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, and nitrogen atmosphere at water temperature. was stirred for 20 hours to obtain a solution of polyamic acid (P1). It was 297 mPa*s when the viscosity of this polyamic acid (P1) solution at 25 degreeC was confirmed with the E-type viscometer (made by Toki Sangyo).

To 50.30 g of this polyamic acid (P1) solution, 5.83 g of N-methyl-2-pyrrolidone solution containing 23.37 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 26.49g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P1 is 5.5 mass % was obtained.

In Table 1, 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 are shown collectively. Similarly, Table 1 shows the amounts (moles) of each tetracarboxylic acid derivative component used in the synthesis of polyamic acids (P2 to P8 and A1 to A6) in Examples 2 to 8 and Comparative Examples 1 to 6 below. And the amount (mol) of each diamine component is also summarized.

Moreover, in Table 2, it showed about A7 which is a liquid mixture of a polyamic acid.

(rubbing resistance evaluation)

After filtering the obtained liquid crystal aligning agent with a 1.0 micrometer filter, it spin-coats on the glass substrate with a transparent electrode, and after drying for 5 minutes on a 50 degreeC hot plate, it bakes at 230 degreeC for 30 minutes, and it has a film thickness of 70 nm 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 press-in amount 0.4 mm). The surface state of this film surface was observed using a confocal laser microscope (manufactured by Lasertech Co., Ltd.), and the presence or absence of scraps and the size thereof were observed at a magnification of 10 times. When there was a lot of film breakage due to rubbing, or when film breakage having a size of 30 μm or more occurred, it was judged to be “defective”. When such a phenomenon did not generate|occur|produce at all, it was judged that rubbing resistance was "good". The evaluation results are shown in Table 3.

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

After filtering the obtained liquid crystal aligning agent with a filter of 1.0 μm, the alignment agent was applied by spin coating on a quartz substrate, dried on a hot plate at 50 ° C. for 5 minutes, and then baked at 230 ° C. for 30 minutes to obtain a film thickness of 70 nm. A polyimide film was formed. Double-sided tape was attached only to the two facing sides of the coated film surface of the substrate, and bonded to a quartz substrate having no film formed thereon. Liquid paraffin was injected into the obtained simple cell, and transmittance was measured using UV-3100PC manufactured by Shimadzu Corporation. The luminous transmittance was calculated from the obtained data, and a value of 96% or more was defined as "good", and a value of less than 96% was defined as "poor" and evaluated. The evaluation results are shown in Table 3. In addition, the luminous transmittance was computed using commercially available software (Shimadzu Corporation color measurement software: P/N206-65207).

(manufacture of liquid crystal cell)

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

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

The pixel electrode of the third layer has a comb-like shape formed by arranging a plurality of z-shaped electrode elements with bent central portions. The width of each electrode element in the width direction is 3 μm, and the interval between the electrode elements is 6 μm. Since the pixel electrode constituting each pixel is composed of a plurality of arranging electrode elements with a curved central portion, the shape of each pixel is not rectangular, but the letter く in bold letters, which is bent in the central portion similarly to the electrode element, is have a similar shape. In addition, each pixel is divided up and down with the central bent part as a boundary, and has a first region above the bend and a second region below the bend.

Comparing the first area and the second area of each pixel, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, the electrode element of the pixel electrode is formed so as to form an angle of +10 ° (clockwise direction) in the first area of the pixel, and the electrode of the pixel electrode in the second area of the pixel The elements are formed to form an angle of -10° (clockwise). That is, in the first area and the second area of each pixel, the rotational motion (in-plane switching) of the liquid crystal caused by the application of the voltage between the pixel electrode and the opposite electrode within the substrate surface is in the opposite direction to each other. It is composed so that

Next, after filtering the obtained liquid crystal aligning agent with a 1.0 micrometer filter, it spin-coated each of the prepared board|substrate with an electrode and the glass substrate in which the ITO film|membrane was formed into a film on the back surface. Subsequently, after drying on a hot plate at 50°C for 5 minutes, it was baked at 230°C for 30 minutes to obtain a polyimide film on each substrate as a coating film having a thickness of 70 nm. After rubbing the polyimide film with a rayon cloth in a predetermined rubbing direction (roll diameter 120 mm, rotation speed 500 rpm, moving speed 30 mm/sec, and pressing amount 0.3 mm), ultrasonic irradiation was performed for 1 minute in pure water. and dried at 80°C for 10 minutes.

After that, a 4 μm bead spacer (manufactured by Nikki Catalyst Chemicals Co., Ltd.) was spread only on the one-sided substrate. Using the two types of substrates with liquid crystal alignment films treated in this way, they were combined so that the respective rubbing directions were antiparallel, and the periphery was sealed leaving the liquid crystal injection port, to prepare an empty cell with a cell gap of 3.6 μm. After vacuum injecting a liquid crystal (MLC-2041, manufactured by Merck Co., Ltd.) into this empty cell at normal temperature, the injection port was sealed to obtain an antiparallel alignment liquid crystal cell. The obtained liquid crystal cell constitutes an IPS mode liquid crystal display element. Then, after heating the obtained liquid crystal cell at 110 degreeC for 1 hour and leaving it to stand overnight, it used for each evaluation.

(Afterimage Recovery Time Evaluation (Afterimage Evaluation))

The residual image was evaluated using the following optical systems and the like.

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

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

In residual image evaluation, a 2V direct-current voltage was applied simultaneously, and it was made to drive for 120 minutes, applying the alternating voltage of the frequency of 30 Hz, and driving a liquid crystal cell, which a relative transmittance becomes 23%. Thereafter, the value of the applied direct current voltage was set to 0 V, only the application of the direct current voltage was stopped, and further driving was performed in that state for 60 minutes.

The afterimage evaluation was evaluated as "good" when the relative transmittance recovered to 25% or less until 60 minutes had elapsed from the point in time when the application of the DC voltage was stopped. When 60 minutes or more was required until the relative transmittance recovered to 25% or less, it was evaluated as "defective".

The residual image evaluation according to the above-mentioned method was performed under two types of temperature conditions: a state in which the temperature of the liquid crystal cell was 23 °C and a state in which the temperature was 60 °C. The evaluation results are shown in Table 3.

(Evaluation of long-term operation (evaluation of residual image))

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

The alternating voltage of _8VPP was applied on the frequency of 30 Hz in a 60 degreeC constant temperature environment using this liquid crystal cell for 100 hours. Then, it was set as the state which shorted between the pixel electrode of a liquid crystal cell and a counter electrode, and it was left to stand at room temperature for one day as it was.

After standing, the liquid crystal cell was installed on two polarizing plates arranged so that the polarization axes were orthogonal, the backlight was turned on in a voltage-free state, and the angle of arrangement of the liquid crystal cell was adjusted so that the luminance of the transmitted light was minimized. Moreover, the rotation angle at the time of rotating the liquid crystal cell from the angle at which the 2nd area|region of a 1st pixel becomes the darkest to the angle at which 1st area|region becomes the darkest was computed as angle (DELTA). Similarly, in the second pixel, the second area and the first area were compared to calculate the same angle Δ. In addition, the average value of the angle Δ values of the first pixel and the second pixel was calculated as the angle Δ of the liquid crystal cell. When the value of the angle Δ of this liquid crystal cell exceeded 0.2 degrees, it was defined as "defective" and evaluated. When the value of the angle Δ of this liquid crystal cell did not exceed 0.2 degree, it was evaluated as "good". 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 stirring device and a nitrogen inlet pipe, and N-methyl-2-pyrrolidone was added. 143.3 g was added and dissolved by stirring while passing nitrogen. While stirring this diamine solution, 10.26 g (47.0 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, and in a nitrogen atmosphere at water temperature. It stirred for 20 hours and obtained the solution of the polyamic acid (P2). It was 305 mPa*s when the viscosity of this polyamic acid (P2) solution at 25 degreeC was confirmed with the E-type viscometer (made by Toki Sangyo Co., Ltd.).

To 50.40 g of this polyamic acid (P2) solution, 5.74 g of N-methyl-2-pyrrolidone solution containing 22.07 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 26.07g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P2 is 5.5 mass % was obtained.

[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 stirring device and a nitrogen inlet pipe, and N-methyl-2-pyrrolidone 62.9 g was added and dissolved by stirring while blowing nitrogen. Stirring this diamine solution, 1.59 g (6.0 mmol) of CA-3 and 9.0 g of N-methyl-2-pyrrolidone were added, and it stirred, sending nitrogen. After stirring for 3 hours, 5.04 g (23.1 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, followed by nitrogen atmosphere at water temperature for 20 hours. It was stirred to obtain a solution of polyamic acid (P3). It was 280 mPa*s as a result of confirming the viscosity of this polyamic acid (P3) solution at 25 degreeC with the E-type viscometer (made by Toki Sangyo Co., Ltd.).

To 83.48 g of this polyamic acid (P3) solution, an N-methyl-2-pyrrolidone solution containing 26.92 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane was added to 9.60 g and 40.0g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P3 is 6.0 mass % was obtained.

[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, and N-methyl-2-pyrrolidone was added. 62.4 g was added and dissolved by stirring while blowing nitrogen. While stirring this diamine solution, 2.85 g (10.8 mmol) of CA-3 and 8.9 g of N-methyl-2-pyrrolidone were added, and the mixture was stirred while blowing nitrogen. After stirring for 3 hours, 3.30 g (15.1 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, followed by nitrogen atmosphere at water temperature for 20 hours. It stirred to obtain a solution of polyamic acid (P4). It was 288 mPa·s as a result of confirming the viscosity of this polyamic acid (P4) solution at 25°C with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

To 82.76 g of this polyamic acid (P4) solution, 9.60 g of N-methyl-2-pyrrolidone solution containing 27.64 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 82.76 g of the polyamic acid (P4) solution. 40.0g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P4 is 6.0 mass % was obtained.

[Example 5]

In a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet pipe, 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 added. ) was added, 64.7 g of N-methyl-2-pyrrolidone was added, and dissolved by stirring while blowing nitrogen. While stirring this diamine solution, 2.43 g (12.4 mmol) of CA-2 and 9.5 g of N-methyl-2-pyrrolidone were added, and the mixture was stirred while blowing nitrogen. After stirring for 1 hour, 3.58 g (16.4 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, followed by nitrogen atmosphere at water temperature for 20 hours. It was stirred to obtain a solution of polyamic acid (P5). It was 264 mPa·s as a result of confirming the viscosity of this polyamic acid (P5) solution at 25°C with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

To 84.21 g of this polyamic acid (P5) solution, 9.60 g of N-methyl-2-pyrrolidone solution containing 26.19 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 84.21 g of this polyamic acid (P5) solution. 40.0g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P5 is 6.0 mass % was obtained.

[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 pipe, and N-methyl-2-pyrrolidone was added. 62.9 g was added and dissolved by stirring while blowing nitrogen. While stirring this diamine solution, 1.22 g (6.2 mmol) of CA-2 and 8.7 g of N-methyl-2-pyrrolidone were added, and the mixture was stirred while blowing nitrogen. After stirring for 1 hour, 5.04 g (23.1 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, followed by nitrogen atmosphere at water temperature for 20 hours. It was stirred to obtain a solution of polyamic acid (P6). It was 262 mPa·s as a result of confirming the viscosity of this polyamic acid (P6) solution at 25°C with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

To 84.96 g of this polyamic acid (P6) solution, 9.60 g of N-methyl-2-pyrrolidone solution containing 25.44 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 40.0g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P6 is 6.0 mass % was obtained.

[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 pipe, and N-methyl-2-pyrrolidone was added. 142.9 g was added and dissolved by stirring while passing nitrogen. 3.87 g (19.7 mmol) of CA-2 and 35.0 g of N-methyl-2-pyrrolidone were added to this diamine solution while stirring, and it stirred while blowing nitrogen. After stirring for 2 hours, 7.82 g (35.9 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, followed by nitrogen atmosphere at water temperature for 20 hours. It was stirred to obtain a solution of polyamic acid (P7). It was 328 mPa·s as a result of confirming the viscosity of this polyamic acid (P7) solution at 25°C with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

To 105.08 g of this polyamic acid (P7) solution, 12.0 g of N-methyl-2-pyrrolidone solution containing 42.93 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 40.0g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P7 is 6.0 mass % was obtained.

[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, and N-methyl-2-pyrrolidone was added. 70.5 g was added and dissolved by stirring while blowing nitrogen. While stirring this diamine solution, 5.86 g (26.9 mmol) of CA-1 was added, N-methyl-2-pyrrolidone was added so that the solid content concentration might be 12% by mass, and the mixture was stirred at 20 °C in a nitrogen atmosphere at water temperature. It stirred for an hour, and obtained the solution of the polyamic acid (P8). It was 311 mPa·s as a result of confirming the viscosity of this polyamic acid (P8) solution at 25°C with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

6.2 g of N-methyl-2-pyrrolidone solution containing 15.61 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane was added to 55.74 g of this polyamic acid (P8) solution. 25.85g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of P8 is 6.0 mass % was obtained.

[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 inlet tube, and they were 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 with water, and 23.35 g (60.9 mmol) of diphenyl(2,3-dihydro-2-thioxo-3-benzooxazolyl)phosphonate was added while stirring with a magnetic stirrer. , 18.75 g of N-methyl-2-pyrrolidone was further added, and stirring was continued for 5 hours. Thereafter, the reaction solution was poured little by little into a place where isopropyl alcohol in an amount 6 times the mass of the reaction solution was being stirred, and stirring was continued for 1 hour. Then, after stirring the precipitate obtained by filtration for 1 hour with isopropyl alcohol of twice the mass, it was filtered again and the precipitate was recovered. Then, this operation|work was repeated twice, and the obtained precipitate was dried under reduced pressure at 100 degreeC for 24 hours, and 10.54-g polyamic acid ester (P9) was obtained. 5.14 g of the obtained 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, and the liquid crystal aligning agent whose density|concentration of P9 is 4.5 mass % was obtained.

[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 pipe, and N-methyl-2-pyrrolidone was added. 73 g was added and dissolved by stirring while passing nitrogen. While stirring this diamine solution, 5.23 g (24.0 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, and in a nitrogen atmosphere at water temperature. After stirring for 20 hours, a solution of polyamic acid (P10) was obtained. It was 327 mPa*s when the viscosity at 25 degreeC of this polyamic-acid solution was confirmed with the E-type viscometer (made by Toki Sangyo).

15.49 g of N -methyl- 2-pyrrolidone and 16.86 g of butyl cellosolves were added to 35.10 g of this polyamic-acid solution, and the liquid crystal aligning agent whose density|concentration of P10 is 6.0 mass % was obtained.

[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 pipe, and N-methyl-2-pyrrolidone was added. 73 g was added and dissolved by stirring while passing nitrogen. While stirring this diamine solution, 5.18 g (23.8 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, and in a nitrogen atmosphere at water temperature. After stirring for 20 hours, a solution of polyamic acid (P11) was obtained. It was 289 mPa*s when the viscosity at 25 degreeC of this polyamic-acid solution was confirmed with the E-type viscometer (made by Toki Sangyo).

10.74 g of N -methyl- 2-pyrrolidone and 8.00g of butyl cellosolves were added to this polyamic-acid solution 11.92g, and the liquid crystal aligning agent whose density|concentration of P11 is 4.5 mass % was obtained.

[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 stirring device and a nitrogen inlet pipe, and N-methyl-2-pyrrolidone 73 g was added and dissolved by stirring while passing nitrogen. While stirring this diamine solution, 5.07 g (23.2 mmol) of CA-1 is added, and N-methyl-2-pyrrolidone is added so that the solid content concentration is 12% by mass, and in a nitrogen atmosphere at water temperature. After stirring for 20 hours, a solution of polyamic acid (P12) was obtained. It was 267 mPa*s when the viscosity at 25 degreeC of this polyamic-acid solution was confirmed with the E-type viscometer (made by Toki Sangyo).

20.62 g of N -methyl- 2-pyrrolidone and 23.49 g of butyl cellosolves were added to 49.84 g of this polyamic-acid solution, and the liquid crystal aligning agent whose density|concentration of P12 is 6.0 mass % was obtained.

[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 pipe, and N-methyl-2-pyrrolidone was added. 79 g was added and dissolved by stirring while passing nitrogen. While stirring this diamine solution, 6.77 g (23.0 mmol) of CA-6 was added, N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, and nitrogen atmosphere at water temperature. was stirred for 20 hours to obtain a solution of polyamic acid (P13). It was 240 mPa*s when the viscosity at 25 degreeC of this polyamic-acid solution was confirmed with the E-type viscometer (made by Toki Sangyo).

7.22 g of N -methyl- 2-pyrrolidones and 7.32 g of butyl cellosolves were added to 14.76 g of this polyamic-acid solution, and the liquid crystal aligning agent whose density|concentration of P13 is 6.0 mass % was obtained.

[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, and the mixture was stirred while blowing nitrogen. dissolved 12.91 g (59.2 mmol) of CA-1 was added stirring this diamine solution under water cooling, N-methyl-2-pyrrolidone was added so that the solid content concentration might be 12 mass %, and 50 It stirred for 20 hours, heating at degreeC, and obtained the solution of the polyamic acid (A1). It was 530 mPa*s when the viscosity at 25 degreeC of this polyamic acid (A1) solution was confirmed with the E-type viscometer (made by Toki Sangyo).

To 50.00 g of this polyamic acid (A1) solution, 5.6 g of N-methyl-2-pyrrolidone solution containing 43.95 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 50.00 g of the polyamic acid (A1) solution. 24.89g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of A1 is 4.5 mass % was obtained.

[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 stirring device and a nitrogen inlet pipe, and N-methyl-2-pyrrolidone was added. 138.1 g was added and dissolved by stirring while passing nitrogen. While stirring this diamine solution under water cooling, 12.59 g (57.7 mmol) of CA-1 was added, N-methyl-2-pyrrolidone was added so that the solid content concentration might be 12 mass %, and 20 It stirred for an hour and obtained the solution of the polyamic acid (A2). It was 310 mPa*s when the viscosity at 25 degreeC of this polyamic acid (A2) solution was confirmed with the E-type viscometer (made by Toki Sangyo).

5.98 g of N-methyl-2-pyrrolidone solution containing 23.18 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane was added to 52.34 g of this polyamic acid (A2) solution. 27.17g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of A2 is 5.5 mass % was obtained.

[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 pipe, and N-methyl-2-pyrrolidone was added. 141.6 g was added and dissolved by stirring while passing nitrogen. Stirring this 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 it stirred, sending nitrogen. After stirring for 2 hours, 5.58 g (25.6 mmol) of CA-1 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, followed by stirring in a nitrogen atmosphere for 20 hours. A solution of polyamic acid (A3) was obtained. It was 276 mPa*s when the viscosity of this polyamic acid (A3) solution at 25 degreeC was confirmed with the E-type viscometer (made by Toki Sangyo).

6.12 g of N-methyl-2-pyrrolidone solution containing 22.01 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane was added to 53.33 g of this polyamic acid (A3) solution. 20.35g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of A3 is 6.0 mass % was obtained.

[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 pipe, and N-methyl-2-pyrrolidone was added. 71.6 g was added and dissolved by stirring while passing nitrogen. While stirring this diamine solution under water cooling, 6.55 g (33.4 mmol) of CA-2 was added, and N-methyl-2-pyrrolidone was added so that the solid content concentration was 12% by mass, and under nitrogen atmosphere. , and stirred for 20 hours to obtain a solution of polyamic acid (A4). It was 274 mPa*s when the viscosity of this polyamic acid (A4) solution at 25 degreeC was confirmed with the E-type viscometer (made by Toki Sangyo Co., Ltd.).

To 20.09 g of this polyamic acid (A4) solution, 2.32 g of N-methyl-2-pyrrolidone solution containing 8.64 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 20.09 g of the polyamic acid (A4) solution. 7.76g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of A4 is 6.0 mass % was obtained.

[Comparative Example 5]

0.84 g (2.8 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-necked flask equipped with a stirrer and a nitrogen inlet tube. ), 72.6 g of N-methyl-2-pyrrolidone was added, and the mixture was dissolved by stirring while blowing nitrogen. 2.67 g (10.1 mmol) of CA-3 was added stirring this diamine solution under water cooling. After stirring for 2 hours, 3.66 g (16.8 mmol) of CA-1 was added, N-methyl-2-pyrrolidone was added so that the solid concentration was 12% by mass, and stirring was performed in a nitrogen atmosphere for 20 hours. A solution of polyamic acid (A5) was obtained. It was 358 mPa·s as a result of confirming the viscosity of this polyamic acid (A5) solution at 25°C with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

To 50.59 g of this polyamic acid (A5) solution, 5.66 g of an N-methyl-2-pyrrolidone solution containing 14.51 g of N-methyl-2-pyrrolidone and 1.0% by mass of 3-aminopropyltriethoxysilane were added to 50.59 g of the polyamic acid (A5) solution. 23.59g of butyl cellosolves were added, and the liquid crystal aligning agent whose density|concentration of A5 is 6.0 mass % was obtained.

[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 pipe, 98.6 g of N-methyl-2-pyrrolidone was added, and the mixture was stirred while blowing nitrogen. dissolved Stirring this diamine solution under water cooling, 6.96 g (35.5 mmol) of CA-2 and 35.9g of N -methyl- 2-pyrrolidone were added, and it stirred under nitrogen atmosphere and water cooling for 3 hours. Then, 1.98 g (10.0 mmol) of DA-5 and 17.9 g of N-methyl-2-pyrrolidone were added, stirred, and dissolved. 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 in a nitrogen atmosphere for 3 hours under water cooling, followed by polyamic acid (A6 ) was obtained. It was 165 mPa·s as a result of confirming the viscosity of this polyamic acid (A6) solution at 25°C with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

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

Moreover, 24.67g of N -methyl- 2-pyrrolidone and 18.66g of butyl cellosolves were added to 50.00 g of polyamic-acid solutions of A1, and the liquid crystal aligning agent whose density|concentration of A1 is 6.0 mass % was also obtained. These two 6.0% by mass solutions were mixed in an amount such that A1:A6 was 2:8 to obtain polyamic acid solution A7.

Using the liquid crystal aligning agents obtained in Examples 2 to 13 and Comparative Examples 1 to 6, in the same manner as in Example 1, evaluation samples such as a film and a liquid crystal cell were prepared, rubbing resistance, luminous transmittance evaluation, residual image evaluation, and Afterimage evaluation by long-term drive was performed. The obtained results are shown in Table 3.

In the film|membrane formed using the liquid crystal aligning agent of Examples 1-13, rubbing tolerance was favorable and the transmittance|permeability was also favorable. Moreover, when applied as a liquid crystal aligning film in evaluation of a liquid crystal cell, there was no temperature dependence of residual image evaluation, and the result of residual image evaluation by long-term drive was also favorable.

On the other hand, in the liquid crystal aligning film formed using the liquid crystal aligning agent of Comparative Examples 1-6, it was difficult to combine an afterimage characteristic and a high transmittance|permeability and also rubbing tolerance, and it turned out that all these items cannot be called favorable. In Comparative Example 1 and Comparative Example 2 in which DA-1 was not used as the diamine component, and in 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.

In Comparative Example 4 in which CA-1 was not used as the tetracarboxylic acid derivative component and in Comparative Example 3 with a small amount introduced, afterimage recovery at 23°C was poor, and in Comparative Example 4, residual image evaluation by long-term driving was poor. It was found that the results were also poor.

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

By using the liquid crystal aligning agent of this invention, it has high transmittance|permeability, it is excellent in rubbing resistance, and the liquid crystal aligning film in which display defects, such as an afterimage, improved in a wide temperature range can be obtained. The liquid crystal alignment film can be used in large-sized liquid crystal televisions, where high display quality has conventionally been required, and in liquid crystal display elements for mobile phones and tablet-type devices, in which display quality has been rapidly improved in recent years. .

In addition, all the content of the JP Patent application 2011-235976, the claim, and the abstract for which it applied on October 27, 2011 is referred here, and it takes in as an indication of the specification of this invention.

Claims (4)

As a liquid crystal aligning agent containing a polyimide precursor obtained by reacting a diamine component and a tetracarboxylic acid derivative,
The diamine component contains a diamine compound represented by the following formula (1) at 20 mol% or more and 60 mol% or less in all diamines (100 mol%), and a diamine compound represented by the following formula (AM1), The tetracarboxylic acid derivative contains 57 mol% or more and 100 mol% or less of an aromatic tetracarboxylic acid derivative,
A liquid crystal orientation characterized in that the aromatic tetracarboxylic acid derivative is pyromellitic dianhydride, 2,5-dicarbomethoxyterephthalic acid or 3,3',4,4'-biphenyltetracarboxylic dianhydride. my.
[Formula 1]

(In Formula (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)
[Formula 2]

(In formula (AM1), R ⁵ has one structure selected from the group consisting of the following formulas (a-1), formulas (a-4), formulas (a-19) and formulas (a-20) represents a divalent organic group, and R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group)
[Formula 3]

According to claim 1,
The liquid crystal aligning agent in which the said diamine component contains the diamine compound represented by said Formula (1) by 30 mol% or more and 60 mol% or less. The liquid crystal aligning film characterized by being obtained from the liquid crystal aligning agent of Claim 1 or 2. The liquid crystal display element characterized by having the liquid crystal aligning film of Claim 3.