KR102604339B1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display device - Google Patents

Abstract

The present invention provides a liquid crystal aligning film that is excellent in rubbing resistance even after a low-temperature baking process, has a desired voltage retention rate, and has reliability, a liquid crystal aligning agent that forms the liquid crystal aligning film, and the liquid crystal aligning film. A liquid crystal display device is provided.
This invention relates to the following (A) component; (B) component; and (C) component; A liquid crystal aligning agent containing a is provided. (A) Component: At least one type of polymer selected from the group consisting of a polyimide precursor and a polyimide obtained by imidization reaction of the polyimide precursor; (B) Component: Compound represented by the following formula (N-1) (wherein, in formula (N-1), R ¹ and R ² represent a straight or branched alkylene group having 1 to 10 carbon atoms, etc. , R ³ and R ⁴ represent a hydrogen atom or a straight-chain or branched alkyl group having 1 to 20 carbon atoms, R ⁵ represents a z-valent aliphatic hydrocarbon group having 1 to 24 carbon atoms, etc.; z is 1 to 6 is an integer.) ; (C) Component: Formulas (1) to (8) below (in formulas (1) to (4) and (8), R ¹¹ to R ¹⁶ and R ²⁰ to R ²¹ each independently represent a compound having 1 to 4 carbon atoms. It represents a linear or branched alkyl group, and in formulas (5) and (6), R ¹⁷ to R ¹⁹ represents an alkyl group having 1 or 2 carbon atoms, and n in formula (7) represents an integer of 1 to 3. ) At least one specific solvent selected from the group consisting of.

Description

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

The present invention provides a liquid crystal aligning film that is excellent in rubbing resistance even when a low-temperature baking process is used, has a desired voltage retention ratio (VHR), and is reliable, a liquid crystal aligning agent that forms the liquid crystal aligning film, and a liquid crystal comprising the liquid crystal aligning film. It relates to display elements.

As a liquid crystal alignment film, a so-called polyimide-based liquid crystal alignment film obtained by applying and baking a liquid crystal aligning agent containing a polyimide precursor such as polyamic acid (also referred to as polyamic acid) or a solution of soluble polyimide as a main component and baking is widely used. .

In the baking process, it is known that good reliability and rubbing resistance can be obtained in the conventional liquid crystal alignment film by baking a polyimide precursor at a high temperature of, for example, 200°C or higher and turning it into polyimide. On the other hand, in recent years, flexible liquid crystal devices using PET films or polycarbonate films as substrates have been examined because of their excellent design properties. Additionally, in order to improve the color reproducibility of liquid crystal displays, a method of mixing quantum dots with a color filter has also been proposed (Patent Document 1). On the other hand, quantum dots still do not have sufficient reliability against heat or light, so there is a problem in that it is difficult to raise the firing temperature of the substrate. Therefore, a low-temperature baking process is being examined from requests, such as the heat resistance of the board|substrate to which a liquid crystal aligning agent is applied, and/or prevention of deterioration of the board|substrate or the member provided on a board|substrate. Additionally, a liquid crystal alignment film material suitable for a low-temperature sintering process has been proposed (Patent Document 2).

However, even if it passes through a low-temperature baking process, it is requested|required that the liquid crystal aligning film obtained has a desired voltage maintenance ratio, and is a reliable liquid crystal aligning film.

WO2014/123836 WO2012/121259

So, the purpose of the present invention is to provide a liquid crystal aligning film obtained even if it has passed through a low-temperature baking process, is excellent in rubbing resistance, has a desired voltage retention, and is reliable.

Moreover, in addition to the said objective, the objective of this invention is to provide a liquid crystal display element provided with the liquid crystal aligning agent which forms this liquid crystal aligning film, and this liquid crystal aligning film.

Furthermore, the purpose of the present invention is to provide a method for producing the liquid crystal alignment film in addition to or in addition to the above purpose.

The present inventors have discovered the following invention.

<1> The following (A) component; (B) component; and (C) component; Liquid crystal aligning agent containing:

(A) Component: At least one type of polymer selected from the group consisting of a polyimide precursor and a polyimide obtained by imidization reaction of the polyimide precursor;

(B) Component: Compound represented by the following formula (N-1);

(C) Component: At least one specific solvent selected from the group consisting of the following formulas (1) to (8).

[Formula 1]

In formula (N-1), R ¹ and R ² are the same or different and represent a linear or branched alkylene group having 1 to 10 carbon atoms, or a cycloalkylene group having 3 to 10 carbon atoms.

R ³ and R ⁴ are the same or different and represent a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms.

R ⁵ represents a z-valent linear or branched aliphatic hydrocarbon group having 1 to 24 carbon atoms, or a z-valent alicyclic hydrocarbon group having 3 to 24 carbon atoms.

Any of a cycloalkane group with 3 to 12 carbon atoms, an aromatic hydrocarbon group with 5 to 12 carbon atoms, (thio)ether, carbonyl, or a tertiary amine may be inserted between the carbon-carbon bonds in the aliphatic hydrocarbon group. The aliphatic hydrocarbon group may have one type of group selected from epoxy and halogen.

Additionally, any of (thio)ether, carbonyl, and tertiary amine may be inserted between the carbon-carbon bonds in the alicyclic hydrocarbon group, and one of the single bonds that do not form a ring is alkyl having 1 to 12 carbon atoms. It may be substituted with a ren group.

z is an integer from 1 to 6.

In formulas (1) to (4) and (8), R ¹¹ to R ¹⁶ and R ²⁰ to R ²¹ each independently represent a straight or branched alkyl group having 1 to 4 carbon atoms, and in formulas (5) and In (6), R ¹⁷ to R ¹⁹ represent an alkyl group having 1 or 2 carbon atoms.

n in formula (7) represents an integer of 1 to 3.

By this invention, even if it passed through a low-temperature baking process, the liquid crystal aligning film obtained is excellent in rubbing resistance, can provide a desired voltage maintenance ratio, and can provide a reliable liquid crystal aligning film.

Moreover, according to this invention, in addition to the said effect, the liquid crystal aligning agent which forms this liquid crystal aligning film, and the liquid crystal display element provided with this liquid crystal aligning film can be provided.

Furthermore, according to the present invention, in addition to the above effects or in addition to the above effects, a method for producing the above liquid crystal alignment film can be provided.

This application provides a liquid crystal aligning agent, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display element provided with the liquid crystal aligning film. Hereinafter, they will be explained in order.

＜Liquid crystal alignment agent＞

The liquid crystal aligning agent of this application is (A) component; (B) component; and (C) component; Contains

＜＜(A) Ingredient＞＞

(A) The component is at least one type of polymer selected from the group consisting of a polyimide precursor and a polyimide obtained by an imidization reaction of the polyimide precursor.

[Polyamic acid]

The polyamic acid according to the present invention can be obtained by reacting a diamine compound and tetracarboxylic dianhydride.

＜Diamine＞

The diamine used in the polymerization of the polyamic acid of the present invention can be generalized by the following formula (1).

[Formula 2]

A ₁ and A ₂ in the above formula (1) are each independently a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkynyl group with 2 to 5 carbon atoms, and Y ₁ is a divalent oil. It is a device. From the viewpoint of liquid crystal orientation, A ₁ and A ₂ are preferably hydrogen atoms or methyl groups. As a preferred embodiment of formula (2), it is preferable to use diamine of the following formula (DA-1).

Moreover, in the above formula (DA-1), Y _d is preferably a divalent organic group represented by the following formulas (Y-1) to (Y-171).

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

^In formula ^{( Y} -87 ^{) ,} , and at least one bond in " ^-CO- -1) It is a group excluding two amino groups from the compounds corresponding to (b-42).

[Formula 8]

[Formula 9]

In the formula (Y-139), R ₁ and R ₂ are an ethylene group, -COO-, -OCO-, -NHCO-, and -N(CH ₃ )CO-, respectively.

[Formula 10]

[Formula 11]

In addition, in the above formula, n is an integer of 1 to 6.

Among the above diamines, from the viewpoint of solubility in a solvent of a polyimide precursor or a polyimide obtained by imidizing the polyimide precursor, Y-1 to Y-6, Y-8, Y-9, Y-14 to Y- 17, Y-20, Y-26 to Y-28, Y-32, Y-38 to Y-42, Y-49 to Y-60, Y-64 to Y-69, Y-72, Y-77, Y-84, Y-86, Y-156, Y-160 to Y-163, Y-165 are preferable, Y-8, Y-9, Y-14, Y-16, Y-17, Y-20 , Y-26 to 28, Y-32, Y-38, Y-68, Y-72, Y-77, Y-84, Y-160, Y-161, and Y-165 are more preferable.

One preferable aspect of the diamine that can be used in the present invention includes diamines having an alkyl group or a fluorine-containing alkyl group in the side chain, which are represented by the following formulas [Sd-1] to [Sd-4].

[Formula 12]

In the formula, A ¹ each independently represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group having 1 to 22 carbon atoms.

As another preferred embodiment of the diamine usable in the present invention, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3 ,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3 ,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl- 3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-dia Minodiphenylethane-3-carboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid, having structures represented by the following formulas [4a-1] to [4a-6] Diamine can be mentioned. The diamine is preferable because it speeds up the curing speed of the liquid crystal alignment film, and it is more preferable to use it together with the diamine that provides vertical alignment, which will be described later. It is preferable to set it as 10 mol% or more, and, as for these diamines, it is more preferable to set it as 20 mol% or more with respect to the whole diamine component used for a liquid crystal aligning agent.

[Formula 13]

As another preferred embodiment of the diamine that can be used in the present invention, diamines represented by the following formulas [2a-1] to formula [2a-9] (n each independently represents an integer of 2 to 12) I can hear it.

[Formula 14]

Another preferred embodiment of the diamine that can be used in the present invention includes a diamine having a heterocyclic ring represented by the following formula (bs).

[Formula 15]

In the above formula [bs],

X ₁ is at least one divalent organic group selected from the group consisting of -O-, -NQ1-, -CONQ1-, -NQ1CO-, -CH ₂ O-, and -OCO-, and Q1 is a hydrogen atom. or an alkyl group having 1 to 3 carbon atoms,

_and

X ₃ is a single binding, or -o-, -nq2-, -conq2-, -nq2co-, -coo-, -Oco-, and -o (CH ₂ ) m- (m) is an integer of 1 to 5 ) is at least one type of divalent organic group selected from the group consisting of,

Q2 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,

X ₄ is a nitrogen -containing aromatic complex, n is an integer of 1 to 4, and preferably, it is a combination described in Table 1 to 3 of the paragraph [0036] to [0038] of the international public public announcement WO2009/093707.

Another preferred embodiment of the diamine that can be used in the present invention includes a diamine having a photoreactive group represented by the following formula (PV-0).

[Formula 16]

In the above formula (PV-0), X ² represents a substituent and is a group having a structure represented by the following formula (2A) or the following formula (2B).

[Formula 17]

In the formulas (2A) and (2B), R is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms (however, any hydrogen atom may be substituted with a fluorine atom), or 1 carbon atom. It represents an alkoxy group of ~18 (however, any hydrogen atom may be substituted with a fluorine atom). A and B each independently represent a single bond or a ring structure shown in the formula below. However, any hydrogen atom in the ring structure may be substituted with an alkoxy group having 1 to 10 carbon atoms. T ¹ to T ⁴ each independently represent a single bond, ether, ester, amide, or ketone bond. S represents a single bond or an alkylene group having 1 to 10 carbon atoms.

In the case of imparting vertical alignment, diamines that can be used in the present invention include diamines represented by formulas [2-1] to [2-31] described in paragraphs [0033] to [0042] of International Publication WO2013/125595. These diamines are preferably used in an amount of 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more based on the total diamine component. From the viewpoint of increasing the curing rate, 90 mol% or less is preferable, and 80 mol% or less is more preferable. A more preferable diamine is at least one type selected from the following formulas [2a-24] to [2a-33].

[Formula 18]

[Formula 19]

In formula (2a-32), when in the ortho position to one of the amino groups, R ¹ is each independently -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, and -CH ₂ Represents at least one type of linking group selected from OCO-, and when in a meta position with respect to two amino groups, R ¹ is, in addition to the linking group shown above, at least one selected from -CONH-, -NHCO-, and -CH ₂ - represents one type of linking group, R ² each independently represents a straight-chain or branched alkyl group having 1 to 22 carbon atoms, a straight-chain or branched alkoxy group having 1 to 22 carbon atoms, and Cy is 4,4'. -It is a group selected from biphenyldiyl group, 4,4'-phenylcyclohexyl group, and 4,4'-dicyclohexyl group.

[Formula 20]

In the above formula, R ₃ represents -O- or -CH ₂ O-, Cy 2 has the same meaning as Cy above, and R ⁷ each independently represents a linear or branched alkyl group having 3 to 12 carbon atoms. , and the cis-trans isomer of 1,4-cyclohexylene represents the trans isomer.

In addition to the diamines mentioned above, 4-(2-(methylamino)ethyl)aniline or the diamine described in Japanese Patent Application Publication No. 2010-97188 can be used.

Among the photoreactive diamines, the following compounds are preferable from the viewpoint of photoreactivity and the like.

[Formula 21]

In the C _n H _2n+1 portion of the particularly preferred diamine compounds exemplified by each of the above formulas, n represents an integer of 0 to 18.

＜Tetracarboxylic dianhydride＞

Examples of tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples of these include the following groups [1] to [5].

[1] Aliphatic tetracarboxylic dianhydride, such as 1,2,3,4-butanetetracarboxylic dianhydride;

[2] Alicyclic tetracarboxylic dianhydride, for example, the following formulas (X1-1) to (X1-13) (in formulas (X1-1) to (X1-4), R ₃ to R ₂₃ is each independently a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, a monovalent organic group with 1 to 6 carbon atoms containing a fluorine atom, or It is a phenyl group, and may be the same or different,

In the above formula, R _M is a hydrogen atom or a methyl group,

Acid dianhydrides such as Xa is a tetravalent organic group represented by the following formulas (Xa-1) to (Xa-7);

[Formula 22]

[Formula 23]

[3] 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran- 2',5'-dione), 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-2 anhydride, 4,9-dioxatricyclo [5.3.1.02, 6] undecane-3,5,8,10-tetraone, etc.;

[4] Aromatic tetracarboxylic dianhydride, for example, pyromellitic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3',4,4'-diphenyl sulfone Tetracarboxylic dianhydride, acid dianhydride represented by the following formulas (Xb-1) to (Xb-10), etc.; and

[Formula 24]

[5] Additionally, acid dianhydrides represented by formulas (X1-44) to (X1-52) and tetracarboxylic dianhydrides described in Japanese Patent Application Publication No. 2010-97188 can be mentioned.

[Formula 25]

In addition, the said tetracarboxylic dianhydride can be used individually or in combination of 2 or more types.

Among the acid dianhydrides, from the viewpoint of solubility in solvents of polyimide precursors or polyimides obtained by imidizing polyimide precursors, X1-1 to X1-3, X1-5 to X1-12, and Xa-1 to Xa-3, Xb-13, X6 to X8, Xb-1, Xb-7 to Xb-9, Xb-13, X1-44, X1-47 to , X1-5 to X1-12, Xa-1 to Xa-3, Xb-7 to Xb-9, X1-44, and X1-49 are more preferable.

<Method for producing polyamic acid>

The polyamic acid used in the present invention can be synthesized by a known method (for example, see International Publication WO2014/034792).

The organic solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the solubility of monomers and polymers, and one or two types of these are used. You may use a mixture of the above. The concentration of the polymer is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoint that polymer precipitation is unlikely to occur and that a high molecular weight body is easy to obtain.

[Polyamic acid ester]

The polyamic acid ester used in the present invention can be obtained as follows.

<Method for producing polyamic acid ester>

The polyamic acid ester used in the present invention is (1) when synthesized from polyamic acid, (2) when synthesized polyamic acid ester from tetracarboxylic acid diester and diamine, or (3) tetracarboxylic acid diester dichloride and In the case of synthesis by reaction of diamine, it can be synthesized by any known method (for example, see International Publication WO2014/034792).

The tetracarboxylic acid diester is as shown in the following reaction formula (wherein, R ¹ is an alkyl group having 1 to 5 carbon atoms, and A is a tetravalent organic group derived from the tetracarboxylic dianhydride.) It can be produced by a known method (for example, see International Publication No. 2010/092989) of reacting tetracarboxylic dianhydride with an alcohol having 1 to 5 carbon atoms represented by R ¹ OH.

[Formula 26]

In the tetracarboxylic acid diester of the present invention, the compound represented by [5-p-1] is preferable from the viewpoint of obtaining a polyamic acid ester with high molecular weight and low dispersion.

Tetracarboxylic acid diester dichloride can be produced, for example, by a known method of chlorinating the tetracarboxylic acid dialkyl ester (see, for example, International Publication No. WO2010/092989).

From the viewpoint of obtaining a polyamic acid ester with high molecular weight and low dispersion, tetracarboxylic acid diester dichloride is used with the formula [5-Cl] (in the above formula (5-Cl), A is A in the above formula (5) It has the same meaning.) Compounds represented by are preferable.

[Formula 27]

The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the viewpoint of solubility of the polyamic acid ester, and these may be used one type or in a mixture of two or more types. The polymer concentration during synthesis is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoint that precipitation of the polymer is difficult to occur and that a high molecular weight body is easy to obtain.

Among the three methods for synthesizing polyamic acid ester, the synthesis method (2) or (3) above is particularly preferable because a high molecular weight polyamic acid ester can be obtained.

[polyimide]

The polyimide used in the present invention can be obtained by a known method (see, for example, International Publication WO2013/125595).

The polyimide may be a complete imidized product in which the entire amic acid structure of the polyamic acid or the amic acid ester structure of the polyamic acid ester is dehydrated and ring-closed, or only a part of the amic acid or amic acid ester structure is dehydrated and ring-closed. , it may be a partial imidide in which an amic acid structure or an amic acid ester structure and an imide ring structure coexist. The polyimide to be used preferably has an imidation rate of 20% or more, and from the viewpoint of ensuring solubility in solvents, it is preferably 90% or less, and more preferably 60% or less. This imidization rate is expressed as a percentage of the ratio of the number of imide ring structures to the total of the number of amic acid structures or amic acid ester structures and the number of imide ring structures of the polyimide. Here, a part of the imide ring may be an isoimide ring.

According to a preferred aspect of the present invention, the component (A) is preferably at least one type of polymer selected from the group consisting of polyimide, polyamic acid, and polyamic acid ester.

According to a more preferred embodiment of the present invention, component (A) is at least one tetracarboxylic acid derivative selected from the group consisting of tetracarboxylic acid dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dichloride; It is a polymer obtained by reacting diamine. At this time, the tetracarboxylic acid dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dichloride are preferably the aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, and aromatic tetracarboxylic acid dianhydride. It is preferable that it contains at least one structure selected from the group consisting of carboxylic acid dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dichloride.

More preferably, it contains a structure having at least one member selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, a cyclohexane ring structure, and a benzene ring structure. Specifically, from the viewpoint of solubility in solvents of polyamic acid, polyamic acid ester, and polyimide obtained by imidizing them, the formulas (X1-1) to (X1-3), (X1-6) to ( X1-12), (XA-1) to (XA-2), Pyromelitic acid anhydride, 4,4 '-(hexamfluoroisopropyliden) diphthalic acid anhydride, (xb-6) ~ (XB-8) , (X1-44), (X1-47) to (X1-52) are preferable, more preferably (X1-1) to (X1-3), (X1-6) to (X1-12), (Xa-1) to (Xa-2), (Xb-6) to (Xb-8), (X1-44), and (X1-49).

More preferred forms of the tetracarboxylic acid derivatives include compounds represented by the following formulas (X1-1-1) to (X1-1-6):

[Formula 28]

Compounds represented by the above formulas (X1-6) to (X1-9), 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride , pyromellitic anhydride, a compound represented by (Xb-6), and at least one compound (T) selected from the group consisting of these tetracarboxylic acid diesters and tetracarboxylic acid diester dichlorides. .

The preferred amount of these compounds (T) used (total amount when two or more types are used) is 10 mol% or more based on the total amount of tetracarboxylic dianhydride and its derivatives used in the synthesis of polyamic acid. It is preferable, it is more preferable that it is 20 mol% or more, and it is still more preferable that it is 30 mol% or more.

The molecular weight of the polyamic acid, polyamic acid ester, and polyimide described in the present invention is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and even more preferably 10,000 to 100,000 in terms of weight average molecular weight. Moreover, the number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 5,000 to 50,000.

＜＜Amount of (A) ingredient＞＞

(A) When the total amount of the liquid crystal aligning agent is 100% by weight, the content of the component is 1 to 15% by weight, preferably 1 to 8% by weight, and more preferably 1.5 to 7% by weight.

＜(B) Ingredient＞

The liquid crystal aligning agent of this application contains (B) component.

(B) Component is a compound represented by the following formula (N-1).

In formula (N-1), R ¹ and R ² are the same or different and represent a linear or branched alkylene group having 1 to 10 carbon atoms, or a cycloalkylene group having 3 to 10 carbon atoms.

The alkylene group and/or the cycloalkylene group may have at least one group selected from the group consisting of ether and tertiary amine. Moreover, the alkylene group may be a saturated or unsaturated alkylene group.

R ¹ and R ² are preferably a linear alkylene group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and are particularly preferably a saturated linear alkylene group having 1 to 2 carbon atoms.

R ³ and R ⁴ are the same or different and represent a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms.

The alkyl group may have at least one type of group selected from the group consisting of ether and tertiary amine. Moreover, the alkyl group may be a saturated or unsaturated alkyl group.

R ³ and R ⁴ are preferably a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, preferably a hydrogen atom.

R ⁵ represents a z-valent aliphatic hydrocarbon group having 1 to 24 carbon atoms, or a z-valent alicyclic hydrocarbon group having 3 to 24 carbon atoms.

Any of a cycloalkane group with 3 to 12 carbon atoms, an aromatic hydrocarbon group with 5 to 12 carbon atoms, (thio)ether, carbonyl, or a tertiary amine may be inserted between the carbon-carbon bonds in the aliphatic hydrocarbon group. The aliphatic hydrocarbon group may have one type of group selected from epoxy and halogen.

Between the carbon-carbon bonds in the alicyclic hydrocarbon group, any of (thio)ether, carbonyl, and tertiary amine may be inserted, and one of the single bonds that do not form a ring is an alkylene group having 1 to 12 carbon atoms. May be substituted;

z is an integer from 1 to 6.

[Formula 29]

Examples of the cycloalkane group having 3 to 12 carbon atoms for R ⁵ include groups obtained by removing two hydrogen atoms from any of cyclopropane, cyclobutane, cyclopentane, cyclohexane, cyclohexene, norbornane, and adamantane.

Examples of the aromatic hydrocarbon group having 5 to 12 carbon atoms for R ⁵ include groups obtained by removing two hydrogen atoms from any of benzene, biphenyl, pyridine, pyrazine, naphthalene, furan, imidazole, oxazole, thiazole, and furan. .

R ⁵ is an alkylene group having 1 to 12 carbon atoms, including methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, and dodecylene. group, vinylene group, propenylene group, butenylene group, pentenylene group, ethynylene group, propynylene group, etc.

When z is 1 and R ⁵ is a monovalent aliphatic hydrocarbon group with 1 to 24 carbon atoms, examples of R ⁵ include an alkyl group with 1 to 24 carbon atoms, an alkenyl group with 2 to 24 carbon atoms, and an alkynyl group with 2 to 24 carbon atoms. You can.

When z is 2 or more and R ⁵ is a divalent or more aliphatic hydrocarbon group having 1 to 24 carbon atoms, as R ⁵ , z - 1 hydrogen atom is removed from the monovalent aliphatic hydrocarbon group having 1 to 24 carbon atoms, thereby creating a bond. You can hear what happened.

When z is 1 and R ⁵ is a monovalent alicyclic hydrocarbon group having 3 to 24 carbon atoms, examples of R ⁵ include monovalent groups such as cycloalkyl group, cyclodecahydronaphthyl group, and adamantyl group.

When z is 2 or more and R ⁵ is a divalent or higher alicyclic hydrocarbon group, examples of R ⁵ include those in which z - 1 hydrogen atom has been removed from the monovalent alicyclic hydrocarbon group having 3 to 24 carbon atoms to form a bond. You can.

As the compound represented by formula (N-1), epoxy compounds having structures represented by the following formulas (N-2-1) to (N-2-4) are preferable.

[Formula 30]

In (N-2-1) to (N-2-4), X each independently represents a single bond, methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, and hexamethylene group.

Y represents any of methylene group, ethylene group, trimethylene group, vinylene group, oxy group, and thio group.

Z represents cyclopentanediyl group, cyclohexanediyl group, or norbornanediyl group.

A compound represented by formula (N-1), having the following formula (N-3-1) to (N-3-4), or 1,3-bis(diglycidylaminomethyl)cyclohexane, 1,4- Bis(diglycidylaminomethyl)cyclohexane, 2,5-bis(diglycidylaminomethyl)norbornane, and 2,6-bis(diglycidylaminomethyl)norbornane are preferred.

[Formula 31]

＜＜Amount of (B) ingredient＞＞

Among the liquid crystal aligning agents of this application, (B) component is 1 to 30 weight% with respect to 100 weight% of component (A), Preferably it is 2 to 20 weight%, More preferably, it is 2 to 15 weight%, Even more preferably, It is preferably 2 to 10% by weight.

＜(C) Ingredient＞

The liquid crystal aligning agent of this application contains at least 1 type of specific solvent chosen from the group which consists of following formulas (1) - (8) as (C) component.

In formulas (1) to (4) and (8), R ¹¹ to R ¹⁶ and R ²⁰ to R ²¹ each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms.

In formulas (5) and (6), R ¹⁷ to R ¹⁹ represent an alkyl group having 1 or 2 carbon atoms.

n in formula (7) represents an integer of 1 to 3.

[Formula 32]

When the total solvent amount of the liquid crystal aligning agent is 100% by weight, the quantity of (C) component is 70% by weight or more, preferably 70 to 100% by weight, and more preferably 80 to 100% by weight.

＜＜Components other than (A) component to (C) component＞＞

The liquid crystal aligning agent of this application may optionally contain components other than (A) component - (C) component mentioned above as appropriate.

For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, 1,3-dimethylimidazolidinone, N,N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2- Methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclo Hexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, di Hexyl ether, dioxane, 1,2-butoxyethane, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, ethylene glycol monoacetate, ethylene glycol diacetate, 2 -(Methoxymethoxy)ethanol, diethylene glycol, propylene glycol, 1-(butoxyethoxy)propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether. , Ethylene glycol monoacetate, ethylene glycol diacetate, Diethylene glycol monoethyl ether acetate, Diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, Diethylene glycol acetate, triethylene glycol, triethylene glycol Ethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, Methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate ester, ethyl lactate ester, lactic acid n-propyl ester, n-butyl lactic acid, isoamyl lactic acid, and organic solvents having the following structures, but are not limited to these.

[Formula 33]

[Formula 34]

[Formula 35]

Among them, from the viewpoint of availability and practicality, a-22, a-13 to a-21, a-24, a-26, a-27, a-31, a-34, a-37, and a-38 It is preferable, and a-22 and a-37 are more preferable.

＜Other crosslinking compounds＞

Components other than components (A) to (C) include crosslinkable compounds.

Examples of the crosslinkable compound include crosslinkable compounds having an epoxy group, isocyanate group, oxetane group, or cyclocarbonate group, and at least one substituent selected from the group consisting of a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group. Crosslinkable compounds or crosslinkable compounds having a polymerizable unsaturated bond may be included, but are not limited to these. Additionally, it is preferable to have two or more of these substituents and polymerizable unsaturated bonds in the crosslinkable compound.

Crosslinkable compounds having an epoxy group or an isocyanate group include, for example, bisphenol acetone glycidyl ether, phenol novolak epoxy resin, cresol novolac epoxy resin, triglycidyl isocyanurate, and tetraglycidyl amino diphenylene. , tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, bisphenol hexafluoroacet diglycidyl ether, 1,3-bis (1- (2,3-epoxypropoxy) -1-trifluoro Romethyl-2,2,2-trifluoromethyl)benzene, 4,4-bis(2,3-epoxypropoxy)octafluorobiphenyl, triglycidyl-p-aminophenol, 2-(4-( 2,3-epoxypropoxy)phenyl)-2-(4-(1,1-bis(4-(2,3-epoxypropoxy)phenyl)ethyl)phenyl)propane or 1,3-bis(4- (1-(4-(2,3-epoxypropoxy)phenyl)-1-(4-(1-(4-(2,3-epoxypropoxy)phenyl)-1-methylethyl)phenyl)ethyl) Phenoxy)-2-propanol, etc. can be mentioned.

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

[Formula 36]

Specifically, crosslinkable compounds represented by formulas [4a] to [4k] published on pages 58 to 59 of International Publication No. WO2011/132751 (published on October 27, 2011) can be cited.

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

[Formula 37]

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

Examples of the crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group and an alkoxyl group include amino resins having a hydroxyl group or an alkoxyl group, such as melamine resin, urea resin, Guanamine resin, glycoluril-formaldehyde resin, succinylamide-formaldehyde resin, or ethylene urea-formaldehyde resin can be mentioned. Specifically, a melamine derivative, benzoguanamine derivative, or glycoluril in which the hydrogen atom of the amino group is substituted with a methylol group or an alkoxymethyl group or both can be used. This melamine derivative or benzoguanamine derivative can also exist as a dimer or trimer. These preferably have an average of 3 to 6 methylol groups or alkoxymethyl groups per triazine ring.

Examples of the above melamine derivatives or benzoguanamine derivatives include commercial products such as MX-750, which has an average of 3.7 methoxymethyl groups substituted per triazine ring, and MW, which has an average of 5.8 methoxymethyl groups substituted per triazine ring. -30 (above, manufactured by Sanwa Chemical) or methoxymethylated melamine such as Cymel 300, 301, 303, 350, 370, 771, 325, 327, 703, 712, Cymel 235, 236, 238, 212, 253 , methoxymethylated butoxymethylated melamine such as 254, butoxymethylated melamine such as Cymel 506 and 508, carboxyl group-containing methoxymethylated isobutoxymethylated melamine such as Cymel 1141, and methoxymethylated ethoxymethylated such as Cymel 1123. Benzoguanamine, methoxymethylated butoxymethylated benzoguanamine such as Cymel 1123-10, butoxymethylated benzoguanamine such as Cymel 1128, methoxymethylated ethoxymethylated benzoguar containing a carboxyl group such as Cymel 1125-80. Namin (above, manufactured by Mitsui Cyanamide Company) can be mentioned. Moreover, examples of glycolurils include butoxymethylated glycolurils such as Cymel 1170, methylolated glycolurils such as Cymel 1172, and methoxymethylolated glycolurils such as Powder Link 1174.

Examples of benzene or phenolic compounds having a hydroxyl group or alkoxyl group include 1,3,5-tris(methoxymethyl)benzene, 1,2,4-tris(isopropoxymethyl)benzene, 1 , 4-bis(sec-butoxymethyl)benzene or 2,6-dihydroxymethyl-p-tert-butylphenol.

More specifically, crosslinkable compounds of formula [6-1] to formula [6-48] published on pages 62 to 66 of International Publication No. WO2011/132751 (published on October 27, 2011) can be cited.

Crosslinkable compounds having a polymerizable unsaturated bond include, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and tri(meth)acrylate. ) Crosslinkable compounds having three polymerizable unsaturated groups in the molecule such as acryloyloxyethoxytrimethylolpropane or glycerin polyglycidyl ether poly(meth)acrylate, also ethylene glycol di(meth)acrylate, Ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol. Di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide bisphenol A type di(meth)acrylate, propylene oxide bisphenol type di(meth)acrylate, 1,6-hexanediol di(meth)acrylate , Glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, diphthalic acid. Crosslinkable compounds having two polymerizable unsaturated groups in the molecule such as glycidyl ester di(meth)acrylate or hydroxypivalic acid neopentyl glycol di(meth)acrylate, and also 2-hydroxyethyl(meth)acrylate Rate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-(meth)acryloyloxy- 2-Hydroxypropyl phthalate, 3-chloro-2-hydroxypropyl (meth)acrylate, glycerin mono (meth)acrylate, 2-(meth)acryloyloxyethyl phosphate ester or N-methylol (meth) and crosslinkable compounds having one polymerizable unsaturated group in the molecule, such as acrylamide.

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

[Formula 38]

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

[Formula 39]

The above is an example of a crosslinkable compound, and is not limited to these. Moreover, the number of crosslinkable compounds used for the liquid crystal aligning agent of this invention may be one, and two or more types may be combined.

The content of the crosslinkable compound in the liquid crystal aligning agent of this invention is preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of all polymer components. Among them, in order for the crosslinking reaction to proceed and achieve the desired effect, 0.1 to 100 parts by mass is preferable with respect to 100 parts by mass of the polymer component. More preferable is 1 to 50 parts by mass.

＜Other optional ingredients＞

The liquid crystal aligning agent of the present invention can use a compound that improves the uniformity and surface smoothness of the film thickness of the liquid crystal aligning film when the liquid crystal aligning agent is applied, as long as the effect of the present invention is not impaired.

Compounds that improve the uniformity and surface smoothness of the film thickness of the liquid crystal alignment film include fluorine-based surfactants, silicone-based surfactants, and non-ionic surfactants. Specific examples of these include the surfactants described in paragraph [0117] of International Publication WO2016/047771.

More specifically, for example, Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megapak F171, F173, R-30 (manufactured by Dainippon Ink), Florad FC430, FC431 (above) (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surfron S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above, manufactured by Asahi Glass), etc.

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

In addition, the liquid crystal aligning agent is a compound that promotes charge transfer in the liquid crystal alignment film to promote charge loss from the device, and has a formula [M1 published on pages 69 to 73 of International Publication No. WO2011/132751 (published on October 27, 2011). ] to a nitrogen-containing heterocyclic amine compound represented by the formula [M156] can also be added. Although this amine compound may be added directly to a liquid crystal aligning agent, it is preferable to add it after setting it as a solution with a density|concentration of 0.1-10 mass %, Preferably it is 1-7 mass %. This solvent is not particularly limited as long as it dissolves the specific polymer (A).

The liquid crystal aligning agent of the present invention includes, in addition to the above-mentioned poor solvents, crosslinkable compounds, compounds that improve the uniformity and surface smoothness of the film thickness of the resin film or liquid crystal aligning film, and compounds that promote charge loss, the effect of the present invention is inhibited. If it is not within the range, a polymer other than the polymer described in the present invention, a silane coupling agent for the purpose of improving the adhesion between the alignment film and the substrate, and further for the purpose of efficiently advancing imidization by heating the polyimide precursor when baking the coating film. An imidization accelerator, etc. may be added.

The liquid crystal aligning agent of this application has the form of a solution containing (A) component - (C) component mentioned above.

The liquid crystal aligning agent used in the present invention has the form of a solution in which a polymer of a specific structure is dissolved in an organic solvent.

The concentration of the polymer of the liquid crystal aligning agent used in the present invention can be appropriately changed depending on the setting of the thickness of the coating film to be formed, but it is preferably 1% by weight or more in terms of forming a uniform and defect-free coating film, and it is preferable to store the solution. In terms of stability, it is preferable to set it to 10% by weight or less.

The liquid crystal aligning agent of the present application can change the solid content concentration (the ratio of the total weight of components other than the (C) component of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) as appropriate depending on the setting of the thickness of the coating film to be formed. , it is preferable that it is 1% by weight or more in terms of forming a uniform and defect-free coating film, and in terms of storage stability of the solution, it is preferable that it is 10% by weight or less.

The range of a particularly preferable solid content concentration varies depending on the method of applying the liquid crystal aligning agent to the substrate.

For example, in the case of using the spinner method, it is particularly preferable that the polymer concentration is in the range of 1.5 to 4.5% by weight. In the case of using the printing method, it is particularly preferable to set the solid content concentration in the range of 3 to 9% by weight, thereby setting the solution viscosity in the range of 12 to 50 mPa·s. In the case of using the inkjet method, it is particularly preferable to set the solid content concentration in the range of 1 to 5% by weight, thereby setting the solution viscosity in the range of 3 to 15 mPa·s.

The polyimide precursor and polyimide, which are component (A) of the present application, preferably have a molecular weight of 2,000 to 500,000 in weight average molecular weight, more preferably 5,000 to 300,000, and even more preferably 10,000 to 100,000. . Moreover, the number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 5,000 to 50,000.

According to another aspect of the present invention, a liquid crystal alignment film formed using the liquid crystal aligning agent of the present invention is provided.

In addition, according to another aspect of the present invention, a step of forming a coating film by applying the liquid crystal aligning agent of the present invention on a substrate, and forming the coating film in a state where the coating film is not in contact with the liquid crystal layer or in a state in contact with the liquid crystal layer. A method for producing a liquid crystal alignment film is provided, including the step of irradiating with light.

Moreover, according to another aspect of this invention, a liquid crystal display element provided with the liquid crystal aligning film by this invention or the liquid crystal aligning film obtained by the said manufacturing method of this invention is provided. Details are shown below.

＜Liquid crystal alignment film/liquid crystal display element＞

By using the liquid crystal aligning agent, a liquid crystal aligning film can be manufactured. Moreover, the liquid crystal display element which concerns on this invention is equipped with the liquid crystal aligning film formed using the said liquid crystal aligning agent. The operation mode of the liquid crystal display device related to the present invention is not particularly limited, for example, TN (Twisted Nematic) type, STN type, vertical alignment type (including VA-MVA type, VA-PVA type, etc.), plane It can be applied to several operation modes, including internal switching type (IPS type), FFS (Fringe Field Switching) type, and optical compensation bend type (OCB type).

The liquid crystal display element according to the present invention can be manufactured, for example, by a process including the following processes (1-1) to (1-3). In process (1-1), the substrate used varies depending on the desired operation mode. Process (1-2) and process (1-3) are common to each operation mode.

[Process (1-1): Formation of coating film]

First, the liquid crystal aligning agent of the present invention is applied onto a substrate, and then the applied surface is heated to form a coating film on the substrate.

(1-1A) For example, when manufacturing a TN type, STN type, or VA type liquid crystal display element, first, two substrates on which a patterned transparent conductive film is formed are paired, and each transparent conductive film is formed. On the surface, the liquid crystal aligning agent prepared above is applied, preferably by an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method. Examples of the substrate include glass such as float glass and soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly(alicyclic olefin) can be used. The transparent conductive film formed on one side of the substrate includes a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG, USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), etc. You can use it. To obtain a patterned transparent conductive film, for example, a method of forming a transparent conductive film without a pattern and then forming a pattern by photo-etching; A method of using a mask with a desired pattern when forming a transparent conductive film; It may be due to etc. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound, etc. are applied in advance to the surface of the substrate on which the coating film is formed. Pretreatment may be performed.

After applying the liquid crystal aligning agent, preliminary heating (prebaking) is preferably performed for the purpose of preventing the liquid crystal aligning agent from flowing down. The prebake temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The prebake time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Thereafter, the solvent is completely removed and, if necessary, a baking (post-bake) process is performed for the purpose of thermally imidizing the amic acid structure present in the polymer. The firing temperature (post-bake temperature) at this time is preferably 80 to 300°C, more preferably 120 to 250°C. The post-bake time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The film thickness of the film formed in this way is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(1-1B) When manufacturing an IPS type or FFS type liquid crystal display device, the electrode formation surface of the substrate on which an electrode made of a transparent conductive film or metal film patterned in a comb shape is formed, and the electrode formation surface on which the electrode is not formed A liquid crystal aligning agent is applied to one surface of the opposing substrate, and then each applied surface is heated to form a coating film. At this time, the materials of the substrate and the transparent conductive film used, the application method, the heating conditions after application, the patterning method of the transparent conductive film or metal film, the pretreatment of the substrate, and the desirable film thickness of the formed coating film are the same as (1-1A) above. do. As the metal film, for example, a film made of a metal such as chromium can be used.

In either case of the above (1-1A) and (1-1B), after applying the liquid crystal aligning agent on the substrate, a liquid crystal aligning film or a coating film used as a liquid crystal aligning film is formed by removing the organic solvent. At this time, by further heating after formation of the coating film, the dehydration ring-closure reaction of the polyamic acid, polyamic acid ester, and polyimide blended with the liquid crystal aligning agent according to the present invention is advanced, and it is good also as a more imidized coating film.

[Process (1-2): Orientation ability granting process]

When manufacturing a TN type, STN type, IPS type or FFS type liquid crystal display element, the coating film formed in the above step (1-1) is subjected to treatment to impart liquid crystal alignment ability. Thereby, the alignment ability of liquid crystal molecules is provided to the coating film, and it becomes a liquid crystal alignment film. Treatments for imparting orientation ability include, for example, a rubbing treatment in which the coating film is rubbed in a certain direction with a roll wrapped in cloth made of fibers such as nylon, rayon, cotton, etc., and a photo-alignment treatment in which polarized or non-polarized radiation is irradiated to the coating film. You can. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1-1) can be used as a liquid crystal alignment film as it is, but the coating film may be subjected to an orientation ability imparting treatment.

When imparting liquid crystal alignment ability to a coating film by photo-alignment treatment, ultraviolet rays and visible rays containing light with a wavelength of 150 to 800 nm can be used as the radiation irradiated to the coating film, for example. If the radiation is polarized, it may be linearly polarized or partially polarized. Additionally, when the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, may be conducted from an oblique direction, or may be performed in combination thereof. When non-polarized radiation is irradiated, the direction of irradiation is oblique.

As the light source used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. Ultraviolet rays in a desirable wavelength range can be obtained by means of using a light source in combination with, for example, a filter, a diffraction grating, etc. The radiation dose is preferably 10 to 5,000 mJ/cm2, and more preferably 30 to 2,000 mJ/cm2.

Additionally, light irradiation to the coating film may be performed while heating the coating film in order to increase reactivity. The temperature during heating is usually 30 to 250°C, preferably 40 to 200°C, and more preferably 50 to 150°C.

In addition, when using ultraviolet rays containing light with a wavelength of 150 to 800 nm, the light irradiation film obtained in the above process can be used as a liquid crystal alignment film as is, but the light irradiation film may be baked. The firing temperature at this time is preferably 80 to 300°C, more preferably 120 to 250°C. The firing time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The photo-alignment process here corresponds to the process of light irradiation in a state not in contact with the liquid crystal layer.

In addition, for the liquid crystal alignment film after the rubbing treatment, a treatment of changing the pretilt angle of a part of the liquid crystal alignment film by irradiating ultraviolet rays to a part of the liquid crystal alignment film, or prior rubbing after forming a resist film on a part of the surface of the liquid crystal alignment film After performing the rubbing process in a direction different from the treatment, a process of removing the resist film may be performed so that the liquid crystal alignment film has a different liquid crystal alignment ability for each region. In this case, it is possible to improve the viewing characteristics of the resulting liquid crystal display element. A liquid crystal alignment film suitable for a VA type liquid crystal display element can also be preferably used for a PSA (polymer sustained alignment) type liquid crystal display element.

[Step (1-3): Construction of liquid crystal cell]

(1-3A) Two substrates on which a liquid crystal alignment film was formed as described above are prepared, and a liquid crystal cell is manufactured by disposing liquid crystal between the two opposing substrates. To manufacture a liquid crystal cell, for example, the following two methods can be used. The first method is a conventionally known method. First, two substrates are placed facing each other with a gap (cell gap) between them so that the respective liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface and the sealant are used to bond the two substrates together. A liquid crystal cell is manufactured by injecting and filling liquid crystal into the defined cell gap and then sealing the injection hole. The second method is called the ODF (One Drop Fill) method. For example, an ultraviolet light-curable sealant is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and the liquid crystal is further dropped at various predetermined points on the liquid crystal alignment film surface, and then the liquid crystal alignment film is formed. A liquid crystal cell is manufactured by bonding the other substrate so that it faces each other, spreading the liquid crystal over the entire surface of the substrate, and then curing the sealant by irradiating ultraviolet light on the entire surface of the substrate. In any case, it is preferable to remove the flow orientation during liquid crystal charging by heating the liquid crystal cell manufactured as above to a temperature at which the liquid crystal used is in an isotropic phase and then slowly cooling it to room temperature. do.

As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.

Liquid crystals include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable, and examples include Schiff-based liquid crystals, azoxy-based liquid crystals, biphenyl-based liquid crystals, phenylcyclohexane-based liquid crystals, and ester-based liquid crystals. Liquid crystals, terphenyl-based liquid crystals, biphenylcyclohexane-based liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, etc. can be used. Moreover, these liquid crystals include, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate; Chiral agents sold under the brand names “C-15” and “CB-15” (manufactured by Merck & Co., Ltd.); It may be used by adding a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate. The liquid crystal may also further include an anisotropic dye. The term “dye” may refer to a material that can intensively absorb or modify light within at least part or the entire range of visible light, for example, within the wavelength range of 400 nm to 700 nm, and the term “anisotropic dye” May refer to a material capable of anisotropic absorption of light in at least part or the entire range of the visible light region. The color of the liquid crystal cell can be adjusted through the use of the above dyes. The type of anisotropic dye is not particularly limited, and for example, black dye or color dye can be used. The ratio of the anisotropic dye to the liquid crystal is appropriately selected within a range that does not impair the desired physical properties. For example, the anisotropic dye may be included in a ratio of 0.01 parts by weight to 5 parts by weight based on 100 parts by weight of the liquid crystal compound. The above ratio can be changed to an appropriate range as needed.

(1-3B) When manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in (1-3A) above except that the photopolymerizable compound is injected or dropped together with the liquid crystal. Thereafter, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of a pair of substrates. The voltage applied here can be, for example, direct current or alternating current of 5 to 50 V. In addition, as the light to be irradiated, for example, ultraviolet rays and visible rays containing light with a wavelength of 150 to 800 nm can be used, but ultraviolet rays containing light with a wavelength of 300 to 400 nm are preferable. As a light source of the irradiated light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. In addition, ultraviolet rays in the above preferred wavelength range can be obtained by means of using a light source in combination with, for example, a filter diffraction grating or the like. The amount of light irradiated is preferably 100 mJ/cm2 or more and less than 20,000 mJ/cm2, and more preferably 100 to 10,000 mJ/cm2.

(1-3C) When a coating film is formed on a substrate using a liquid crystal aligning agent containing a compound (polymer or additive) having a photopolymerizable group, a liquid crystal cell is constructed in the same manner as in (1-3A) above, Thereafter, a method of manufacturing a liquid crystal display element may be adopted by going through a step of irradiating light to the liquid crystal cell while applying a voltage between the conductive films of a pair of substrates. According to this method, the merits of the PSA mode can be realized with a small amount of light irradiation. Light irradiation to the liquid crystal cell may be performed in a state in which the liquid crystal is driven by voltage application, or may be performed in a state in which a voltage low enough not to drive the liquid crystal is applied. The applied voltage can be, for example, direct current or alternating current of 0.1 to 30 V. Regarding the conditions of the light to be irradiated, the explanation in (1-3B) above can be applied. The light irradiation process here corresponds to the light irradiation process in a state in contact with the liquid crystal layer.

And the liquid crystal display element according to the present invention can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. Examples of the polarizing plate bonded to the outer surface of the liquid crystal cell include a polarizing film called an "H film" in which iodine is absorbed while stretching polyvinyl alcohol, sandwiched between a cellulose acetate protective film, or a polarizing plate made of the H film itself. .

The liquid crystal display element related to the present invention can be effectively applied to various devices, for example, watches, portable games, word processors, laptop computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, and smart devices. It can be used in various display devices such as phones, various monitors, liquid crystal televisions, and information displays.

As described above, by using the liquid crystal aligning agent of the present invention, a liquid crystal aligning film excellent in the uniformity of the film thickness within the application surface, the linearity of the application peripheral portion, and dimensional stability can be obtained.

Moreover, by using the liquid crystal aligning agent of this invention, voltage retention becomes a desired value, excellent rubbing resistance, and a reliable liquid crystal aligning film can be obtained.

Example

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

The structures of the compounds used in the examples are shown below.

＜Tetracarboxylic dianhydride＞

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

BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic acid dianhydride

PMDA: Pyromellitic dianhydride

TCA: 2,3,5-tricarboxycyclopentylacetic acid-1,4,2,3-2 anhydride

＜Diamine compound＞

p-PDA: p-phenylenediamine

DBA: 3,5-diaminobenzoic acid

PCH7: 1,3-diamino-4-[4-(trans-4-n-heptylcyclohexyl)phenoxy]benzene

APC12: 1,3-diamino-4-(dodecanoxy)benzene

PBCH5: 1,3-diamino-4-{4-[trans-4-(trans-4-n-pentylcyclohexyl)cyclohexyl]phenoxy}benzene

DA-3: 2,2-bis[4-(4-aminophenoxy)phenyl]propane

The structures of component (B) used in the examples and the crosslinking agent species used in the comparative examples are shown below.

[Formula 40]

The symbols for the organic solvents used in the examples and the like are as follows.

NMP: N-methyl-2-pyrrolidone

GBL: γ-butylactone

BCS: Butylcellosolve

CHN: Cyclohexanone

CPN: Cyclopentanone

PGME: propylene glycol monomethyl ether

EC: ethylcarbitol

DME: diethylene glycol dimethyl ether

＜Measurement of polymer molecular weight＞

The molecular weight of the polymer in the synthesis example was measured as follows using a room temperature gel permeation chromatography (GPC) device (SSC-7200, manufactured by Senshu Science Co., Ltd., and a column (KD-803, KD-805) manufactured by Shodex Co., Ltd.).

Column temperature: 50℃

Eluent: DMF (as additives, lithium bromide-hydrate (LiBr·H ₂ O) is 30 mmol/L, phosphoric acid/anhydrous crystal (o-phosphoric acid) is 30 mmol/L, and THF is 10 mL/L)

Flow rate: 1.0 mL/min

Standard samples for creating a calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weights approximately 9,000,000, 150,000, 100,000, 30,000), and polyethylene glycol manufactured by Polymer Laboratories (molecular weights approximately 12,000, 4,000, 1,000).

(Measurement of molecular weight of polyimide)

The molecular weight of the polyimide in the synthesis example was determined using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko) and columns (KD-803, KD-805) (manufactured by Shodex). It was measured as follows.

Column temperature: 50℃

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

Flow rate: 1.0 mL/min

Standard samples for creating a calibration curve: TSK standard polyethylene oxide (molecular weight approximately 900,000, 150,000, 100,000, 30,000) (manufactured by Tosoh) and polyethylene glycol (molecular weight approximately 12,000, 4,000, 1,000) (manufactured by Polymer Laboratory).

(Measurement of imidization rate)

The imidization rate of the polyimide in the synthesis example was measured as follows. Polyimide powder (20 mg) was placed in an NMR sample tube (NMR sampling tube standard ϕ5 (manufactured by Cusano Scientific)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture) (0.53 ml) ) was added and ultrasonic waves were applied to completely dissolve it. The proton NMR of this solution was measured at 500 MHz using an NMR measuring device (JNW-ECA500) (manufactured by JEOL Datum). The imidization rate is determined by using a proton derived from a structure that does not change before and after imidization as a reference proton, and using the peak integration value of this proton and the proton peak integration value derived from the NH group of amidic acid appearing around 9.5 to 10.0 ppm. It was obtained using the formula below.

Imidation rate (%) = (1 - α·x/y) × 100

In the above formula, x is the integrated peak value of the proton derived from the NH group of amidic acid, y is the integrated peak value of the reference proton, and α is NH of amidic acid in the case of polyamic acid (imidation rate of 0%). It is the ratio of the number of standard protons to one basic proton.

＜Synthesis of polyimide＞

<Synthesis Example 1>

BODA (18.8 g, 75 mmol), DBA (7.6 g, 50 mmol), and PCH7 (21.7 g, 50 mmol) were mixed in NMP (148.0 g) and reacted at 80°C for 5 hours, then CBDA (4.8 g, 24 mmol) and NMP (63.5 g) were added and reacted at 40°C for 12 hours to obtain a polyamic acid solution.

NMP was added to this polyamic acid solution (50.0 g) and diluted to 6% by mass, and then acetic anhydride (5.8 g) and pyridine (4.6 g) were added as imidization catalysts, and the mixture was allowed to react at 80°C for 3 hours. This reaction solution was poured into methanol (600 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, dried under reduced pressure at 100°C, and polyimide powder (A) was obtained. The imidation rate of this polyimide was 57%, the number average molecular weight was 17800, and the weight average molecular weight was 53400.

<Synthesis Example 2>

BODA (12.5 g, 50 mmol), DBA (9.1 g, 60 mmol), and PCH7 (15.2 g, 40 mmol) were mixed in NMP (147.6 g) and reacted at 80°C for 5 hours, then CBDA (9.8 g, 50 mmol) and NMP (39.1 g) were added and reacted at 40°C for 12 hours to obtain a polyamic acid solution.

After adding NMP to this polyamic acid solution (80.0 g) and diluting it to 6% by mass, acetic anhydride (15.4 g) and pyridine (8.9 g) were added as imidization catalysts, and the mixture was allowed to react at 50°C for 3.5 hours. This reaction solution was poured into methanol (1000 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, dried under reduced pressure at 100°C, and polyimide powder (B) was obtained. The imidation rate of this polyimide was 51%, the number average molecular weight was 20100, and the weight average molecular weight was 68100.

<Synthesis Example 3>

BODA (18.8 g, 75 mmol), DBA (10.7 g, 70 mmol), and PBCH5 (13.0 g, 30 mmol) were mixed in NMP (132.2 g) and reacted at 80°C for 5 hours, then CBDA (4.7 g, 24 mmol) and NMP (56.7 g) were added and reacted at 40°C for 12 hours to obtain a polyamic acid solution.

After adding NMP to this polyamic acid solution (50.0 g) and diluting it to 6% by mass, acetic anhydride (8.6 g) and pyridine (6.6 g) were added as imidization catalysts, and the mixture was allowed to react at 80°C for 3.5 hours. This reaction solution was poured into methanol (650 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, dried under reduced pressure at 100°C, and polyimide powder (C) was obtained. The imidation rate of this polyimide was 57%, the number average molecular weight was 18500, and the weight average molecular weight was 52700.

<Synthesis Example 4>

CBDA (3.9 g, 20 mmol), DA-3 (36.9 g, 90 mmol), and APC12 (2.9 g, 10 mmol) were mixed in NMP (240.1 g) and reacted at room temperature for 1 hour, then PMDA (16.8 g) , 77 mmol) and NMP (103.3 g) were added and reacted at room temperature for 2 hours to obtain a polyamic acid solution (D).

The number average molecular weight of this amic acid was 17,200 and the weight average molecular weight was 62,000.

<Synthesis Example 5>

TCA (5.1 g, 22.9 mmol), DBA (2.5 g, 16.1 mmol), and PCH7 (2.6 g, 6.9 mmol) were mixed in NMP (40.8 g) and reacted at 60°C for 24 hours to obtain a polyamic acid solution. .

NMP was added to this polyamic acid solution (20.0 g) and diluted to 6% by mass, and then acetic anhydride (2.3 g) and pyridine (1.8 g) were added as imidization catalysts, and the mixture was allowed to react at 90°C for 2 hours. This reaction solution was poured into methanol (248 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, dried under reduced pressure at 100°C, and polyimide powder (E) was obtained. The imidation rate of this polyimide was 51%, the number average molecular weight was 16,100, and the weight average molecular weight was 37,200.

<Synthesis Example 6>

CBDA (19.0 g, 97 mmol), p-PDA (3.2 g, 30 mmol), and PCH7 (26.6 g, 70 mmol) were mixed in NMP (277.1 g) and reacted at room temperature for 24 hours to give a polyamic acid solution (F ) was obtained.

The number average molecular weight of this amic acid was 18700 and the weight average molecular weight was 56100.

<Examples 1 to 4>

GBL (3.8 g) and PGME were added to 1 g each of the polyimide powders (A), (B), (C), and (E) obtained in Synthesis Example 1, Synthesis Example 2, Synthesis Example 3, and Synthesis Example 5. (20.0 g) was added and stirred at 70°C for 15 hours to obtain a polyimide solution. No abnormalities such as cloudiness or precipitation were observed in any of the polyimide solutions, and it was confirmed that they were uniform solutions.

Next, liquid crystal aligning agents (1) to (4) were obtained by adding a 10 wt% PGME solution (0.3 g) of TETRAD-C to these polyimide solutions and stirring at room temperature for 30 minutes.

Using the obtained liquid crystal aligning agents (1) to (4), evaluation of the solvent drying rate, evaluation of rubbing resistance, preparation of the liquid crystal cell, and evaluation of the voltage retention of the liquid crystal cell were performed.

Various evaluations were similarly performed on Examples 5 to 13 and Comparative Examples 1 to 3. The evaluation results of the solvent drying speed of the examples and comparative examples are shown in Table 1, the evaluation results of the rubbing resistance are shown in Table 2, and the evaluation results of the voltage retention of the liquid crystal cell are shown in Table 3.

<Example 5>

A polyimide solution was obtained by adding GBL (6.3 g) and PGME (17.3 g) to 1 g of polyimide powder (A) obtained in Synthesis Example 1 and stirring at 70°C for 15 hours. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution. Next, a 10 wt% PGME solution (0.5 g) of TETRAD-C was added to this polyimide solution, and the liquid crystal aligning agent (5) was obtained by stirring at room temperature for 30 minutes.

<Examples 6 to 8>

To each 1 g of polyimide powder (A), (B), and (C) obtained in Synthesis Example 1, Synthesis Example 2, and Synthesis Example 3, GBL (6.3 g), PGME (12.5 g), and DME ( 5.0 g) was added and stirred at 70°C for 15 hours to obtain a polyimide solution. No abnormalities such as cloudiness or precipitation were observed in any of the polyimide solutions, and it was confirmed that they were uniform solutions. Next, liquid crystal aligning agents (6) to (8) were obtained by adding a 10 wt% PGME solution (0.3 g) of TETRAD-C to these polyimide solutions and stirring at room temperature for 30 minutes.

<Example 9>

A polyimide solution was obtained by adding PGME (18.9 g) and EC (5.0 g) to 1 g of polyimide powder (A) obtained in Synthesis Example 1 and stirring at 70°C for 15 hours. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution. Next, a 10 wt% PGME solution (0.3 g) of TETRAD-C was added to these polyimide solutions, and the liquid crystal aligning agent (9) was obtained by stirring at room temperature for 30 minutes.

<Examples 10 to 13>

GBL (3.8 g) and PGME were added to 1 g each of the polyimide powders (A), (B), (C), and (E) obtained in Synthesis Example 1, Synthesis Example 2, Synthesis Example 3, and Synthesis Example 5. (8.9 g) and CHN (8.9 g) were added and stirred at 70°C for 15 hours to obtain a polyimide solution. No abnormalities such as cloudiness or precipitation were observed in any of the polyimide solutions, and it was confirmed that they were uniform solutions. Next, liquid crystal aligning agents (10) to (13) were obtained by adding a 10 wt% PGME solution (0.5 g) of TETRAD-C to these polyimide solutions and stirring at room temperature for 30 minutes.

<Example 14>

CHN (7.5 g), PGME (20.6 g), and a 10% by weight PGME solution of TETRAD-C (0.75 g) were added to 10 g of the polyamic acid solution (D) obtained in Synthesis Example 4, and incubated at room temperature for 30 minutes. By stirring, the liquid crystal aligning agent (14) was obtained. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution.

Using the obtained liquid crystal aligning agent (14), evaluation of the solvent drying rate, evaluation of rubbing resistance, preparation of a liquid crystal display element, and evaluation of the liquid crystal orientation were performed.

<Example 15>

To 10 g of the polyamic acid solution (D) obtained in Synthesis Example 4, CPN (7.5 g), PGME (20.6 g), and a 10% by weight PGME solution of TETRAD-C (0.75 g) were added, and incubated at room temperature for 30 minutes. By stirring, the liquid crystal aligning agent (15) was obtained. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution.

<Example 16>

To 10 g of the polyamic acid solution (F) obtained in Synthesis Example 6, BCS (7.5 g), PGME (20.6 g), and a 10% by weight PGME solution of TETRAD-C (0.75 g) were added, and incubated at room temperature for 30 minutes. By stirring, the liquid crystal aligning agent (16) was obtained. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution.

<Example 17>

To 10 g of the polyamic acid solution (D) obtained in Synthesis Example 4, BCS (7.5 g), PGME (20.6 g), and a 10% by weight PGME solution of TETRAD-C (0.75 g) were added, and incubated at room temperature for 30 minutes. By stirring, the liquid crystal aligning agent (16) was obtained. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution.

<Comparative Example 1>

A polyimide solution was obtained by adding NMP (16.2 g) and BCS (7.5 g) to 1 g of polyimide powder (A) obtained in Synthesis Example 1 and stirring at 70°C for 15 hours. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution. This polyimide solution was used as the liquid crystal aligning agent (17).

<Comparative Example 2>

A polyimide solution was obtained by adding NMP (16.2 g) and BCS (7.5 g) to 1 g of polyimide powder (A) obtained in Synthesis Example 1 and stirring at 70°C for 15 hours. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution. Next, a 10 wt% NMP solution (0.3 g) of TMBIP was added to these polyimide solutions, and the liquid crystal aligning agent (18) was obtained by stirring at room temperature for 30 minutes.

<Comparative Example 3>

A polyimide solution was obtained by adding NMP (16.2 g) and BCS (7.5 g) to 1 g of polyimide powder (A) obtained in Synthesis Example 1 and stirring at 70°C for 15 hours. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution. Next, a 10 wt% NMP solution (0.3 g) of GT401 was added to these polyimide solutions, and the liquid crystal aligning agent (19) was obtained by stirring at room temperature for 30 minutes.

<Comparative Example 4>

To 10 g of the polyamic acid solution (D) obtained in Synthesis Example 4, NMP (19.6 g), BCS (7.5 g), and a 10% by weight NMP solution of TETRAD-C (0.45 g) were added, and incubated at room temperature for 30 minutes. By stirring, the liquid crystal aligning agent (20) was obtained. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution.

<Comparative Example 5>

A polyimide solution was obtained by adding NMP (16.2 g) and BCS (7.5 g) to 1 g of polyimide powder (A) obtained in Synthesis Example 1 and stirring at 70°C for 15 hours. No abnormalities such as cloudiness or precipitation were observed in this polyimide solution, and it was confirmed that it was a uniform solution. Next, a 10 wt% NMP solution (0.5 g) of TMBIP and a 10 wt% NMP solution (0.3 g) of PTSA were added to these polyimide solutions, and the liquid crystal aligning agent (21) was obtained by stirring at room temperature for 30 minutes.

<Evaluation of solvent drying speed>

The liquid crystal aligning agent of the present invention obtained in Examples (1) to (13) and Comparative Examples (1) to (5) was spin coated on a glass substrate with a transparent electrode so that the film thickness of the dried coating film was 100 nm, It was placed on a hot plate at 30°C and the time until the solvent dried was observed.

<Evaluation of rubbing resistance>

The liquid crystal aligning agent of this invention obtained in Examples (1) - (17) and Comparative Examples (1) - (5) is spin-coated on a glass substrate with a transparent electrode, and the solvent is dried on a 50°C hot plate for 120 seconds. After this, baking was performed on a 120°C hot plate for 5 minutes to form a coating film with a film thickness of 100 nm. This coated film surface was rubbed using a rayon cloth using a rubbing device with a roll diameter of 120 mm under the conditions of a roll rotation speed of 1000 rpm, a roll advancing speed of 50 mm/sec, and an indentation amount of 0.3 mm, and a substrate with a liquid crystal aligning film was obtained.

The surface of the liquid crystal alignment film near the center of the substrate is observed at random at five points using a laser microscope set at a magnification of 100 times, and the amount of rubbing scratches and rubbing residue (deposits) is confirmed in the observation field of about 6.5 mm in all directions. Rubbing resistance was evaluated from the average value. The results are summarized in Table 1. Additionally, the evaluation criteria were set as follows.

Evaluation standard

○: No more than 20 rubbing scratches or rubbing residue.

△: 20 to 40 rubbing scratches or rubbing residue.

×: 40 or more rubbing scratches or rubbing residue

[Fabrication of vertically aligned liquid crystal cell]

The liquid crystal aligning agent of the present invention obtained in Examples (1) to (13) and Comparative Examples (1) to (3) and (5) was spin coated on the ITO surface of a glass substrate with a transparent electrode made of an ITO film. , after drying on a 50°C hot plate for 120 seconds, baking was performed in a 120°C IR oven for 10 minutes to form a liquid crystal alignment film with a film thickness of 100 nm. Next, this coated film surface was rubbed using a rayon cloth with a rubbing device with a roll diameter of 120 mm under the conditions of a roll rotation speed of 1000 rpm, a roll advancing speed of 50 mm/sec, and an indentation amount of 0.3 mm, and a substrate with a liquid crystal aligning film was obtained.

Two of the above-described substrates were prepared, and a 4-μm bead spacer was spread on the liquid crystal alignment film of one of the substrates, and then a sealant (XN-1500T, manufactured by Kyoritsu Chemical Co., Ltd.) was applied. Next, the other board was bonded together so that the liquid crystal alignment film surfaces faced each other and the orientation direction was 180°, and then the sealant was heat-cured at 120°C for 90 minutes to produce an empty cell. A negative liquid crystal (MLC-3022, manufactured by Merck & Co., Ltd.) was injected into this empty cell by a reduced-pressure injection method to produce a liquid crystal cell.

After fabricating the liquid crystal cell, isotropic treatment was performed at 120°C for 1 hour, and then the cell was observed with a polarizing microscope. It was confirmed that there were no alignment defects such as light leakage or domain generation in any of the liquid crystal cells, and that uniform liquid crystal orientation was obtained. .

＜Evaluation of voltage retention rate of liquid crystal cell＞

A voltage of 1 V was applied to the liquid crystal cell produced above for 60 μs at a temperature of 60°C, the voltage after 1667 ms was measured, and the extent to which the voltage was maintained was calculated as the voltage retention rate. The measurement was performed using a VHR-1 voltage retention measuring device manufactured by Toyo Technica, with settings of Voltage: ±1 V, Pulse Width: 60 μs, and Flame Period: 1667 ms.

Industrial applicability

A liquid crystal display element using a liquid crystal aligning film obtained from the liquid crystal aligning agent of the present invention can be suitably used for display elements of various liquid crystal modes. Additionally, these elements are useful in liquid crystal displays for display purposes, and also in light dimming windows and optical shutters that control the transmission and blocking of light.

Claims (6)

(A) component below; (B) component; and (C) component; The process of apply|coating the liquid crystal aligning agent containing this on a board|substrate, preheating it at 30-50 degreeC for 0.25-2 minutes, and baking it at the baking temperature of 80-120 degreeC for 5-10 minutes after that;
A method for producing a liquid crystal alignment film, wherein the liquid crystal alignment film is formed by removing the component (C): a specific solvent:
(A) Ingredients:
At least one type of polymer selected from the group consisting of a polyimide precursor and a polyimide obtained by imidation reaction of the polyimide precursor;
(B) Ingredients:
Compounds represented by the following formula (N-2-1), (N-2-2) or (N-2-4)
(Wherein,
Z represents a cyclopentanediyl group, cyclohexanediyl group, or norbornanediyl group.);
(C) Ingredients:
The following formulas (1), (2), (5) to (7)
(In formulas (1) and (2), R ₁₁ and R ₁₂ each independently represent a straight-chain or branched alkyl group having 1 to 4 carbon atoms, and in formulas (5) and (6), R ₁₇ to R ₁₉ each independently represents an alkyl group having 1 or 2 carbon atoms.
n in equation (7) represents an integer from 1 to 3.)
At least one specific solvent selected from the group consisting of.
According to claim 1,
A method for producing a liquid crystal alignment film in which the (C) component is 70% by weight or more in 100% by weight of the total solvent amount of the liquid crystal aligning agent. According to claim 1,
(A) The component is a polymer obtained by reacting a diamine with at least one tetracarboxylic acid derivative selected from the group consisting of tetracarboxylic acid dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dihalide, ,
The manufacturing method of a liquid crystal alignment film in which the said tetracarboxylic acid derivative contains a compound which has at least 1 type chosen from the group which consists of a cyclobutane ring structure, a cyclopentane ring structure, a cyclohexane ring structure, and a benzene ring structure. The method according to any one of claims 1 to 3,
A method of producing a liquid crystal alignment film, further comprising the step of irradiating light to the liquid crystal alignment film while the liquid crystal alignment film is not in contact with the liquid crystal layer or in a state in which the liquid crystal alignment film is in contact with the liquid crystal layer. A liquid crystal aligning film formed by the manufacturing method of the liquid crystal aligning film according to any one of claims 1 to 3. A liquid crystal display element comprising the liquid crystal alignment film according to claim 5.