TWI773714B - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

The present invention provides a liquid crystal alignment film obtained by a low-temperature firing process, which has excellent rubbing resistance, a desired voltage holding ratio, and a reliable liquid crystal alignment film, a liquid crystal alignment agent for forming the liquid crystal alignment film, and a liquid crystal alignment film having the liquid crystal alignment film. The liquid crystal display element of the alignment film. The present invention provides a liquid crystal aligning agent containing the following (A) component; (B) component; and (C) component;. (A) Component: at least one polymer selected from the group consisting of a polyimide precursor and a polyimide obtained by an imidization reaction of the polyimide precursor; (B) Component: a compound represented by the following formula (N-1) (in the formula, in the formula (N-1), R ¹ and R ² represent a linear or branched alkyl group with 1 to 10 carbon atoms, etc., R ³ and R ⁴ represents a hydrogen atom, or a linear or branched alkyl group with a carbon number of 1 to 20, and R ⁵ represents a z-valent aliphatic hydrocarbon group with a carbon number of 1 to 24, etc.; z is an integer of 1 to 6); ( C) Component: selected from the following formulae (1) to (8) (in formulae (1) to (4) and (8), R ¹¹ to R ¹⁶ and R ²⁰ to R ²¹ each independently represent a carbon number of 1 to 4 In formula (5) and (6), R ¹⁷ ~ R ¹⁹ represent an alkyl group with 1 or 2 carbon atoms, and n in formula (7) represents an integer of 1 to 3). A group of at least one specific solvent.

Description

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

The present invention relates to a liquid crystal alignment film that is excellent in rubbing resistance, has a desired voltage holding ratio (VHR), and has reliability even when a low-temperature firing step is used, a liquid crystal alignment agent for forming the liquid crystal alignment film, and a liquid crystal alignment film having the liquid crystal alignment film. Alignment film for liquid crystal display elements.

The liquid crystal alignment film is coated with a polyimide precursor such as polyamic acid (also known as polyamic acid) or a liquid crystal alignment agent with a solution of soluble polyimide as the main component. After firing, the so-called polyimide Imine-based liquid crystal alignment films are widely used. In the firing step, in the conventional liquid crystal alignment film system, a polyimide precursor is fired at a high temperature of, for example, 200°C or higher, and it is known that good reliability and rubbing resistance can be obtained as a polyimide. In addition, in recent years, flexible liquid crystal elements using a PET film or a polycarbonate film as a substrate have been examined due to their excellent creativity. In addition, in order to improve the color reproducibility of a liquid crystal display, a method of mixing quantum dots in a color filter has been proposed (Patent Document 1). In addition, the reliability of quantum dots with respect to heat or light is still insufficient, and it is difficult to raise the firing temperature of the substrate. Therefore, since the heat resistance of the substrate on which the liquid crystal alignment agent is applied, and/or the degradation prevention of the substrate or the member provided in the substrate is required, the low-temperature firing process is reviewed. In addition, a liquid crystal alignment film material suitable for a low-temperature firing process is proposed (Patent Document 2).

However, even the liquid crystal alignment film obtained by the low-temperature firing process is required to have the desired voltage holding ratio and a reliable liquid crystal alignment film. [Prior Art Literature] [Patent Literature]

[Patent Document 1] WO2014/123836. [Patent Document 2] WO2012/121259.

[The problem to be solved by the invention]

Therefore, the object of the present invention is to provide a liquid crystal alignment film which is excellent in rubbing resistance, has a desired voltage holding ratio, and has reliability even if a liquid crystal alignment film obtained by a low-temperature firing process. Furthermore, in addition to the above-mentioned objects, the object of the present invention is to provide a liquid crystal alignment agent for forming the liquid crystal alignment film, and a liquid crystal display element provided with the liquid crystal alignment film. In addition, the object of the present invention is to provide a method for producing the above-mentioned liquid crystal alignment film in addition to the above-mentioned object or in addition to the above-mentioned object. [means to solve the problem]

The present inventors discovered the following invention. <1> A liquid crystal aligning agent comprising the following (A) component; (B) component; and (C) component; (A) component: selected from a polyimide precursor, and a A polymer of at least one type of polyimide group obtained by imidization of an amine precursor; Component (B): a compound represented by the following formula (N-1); Component (C): selected from A specific solvent of at least one of the following formulae (1) to (8).

In formula (N-1), R ¹ and R ² represent the same or different, linear or branched alkylene with 1-10 carbon atoms, or cycloalkylene with 3-10 carbon atoms. R ³ and R ⁴ represent the same or different, 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. Between the carbon-carbon bonds in the aliphatic hydrocarbon group, any one of a cycloalkyl group having 3 to 12 carbon atoms, an aromatic hydrocarbon group having a carbon number of 5 to 12, (thio)ether, carbonyl group and tertiary amine can be inserted , the aliphatic hydrocarbon group may have a group selected from epoxy group and halogen. In addition, between the carbon-carbon bonds in the alicyclic hydrocarbon group, any one of (thio)ether, carbonyl, and tertiary amines can be inserted, and one of the single bonds that do not form a ring can be replaced by a carbon number of 1 to 12. Alkylene substitution. 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 linear or branched alkyl group with 1 to 4 carbon atoms, and formulas (5) and (6) ), R ¹⁷ to R ¹⁹ represent an alkyl group with 1 or 2 carbon atoms. n in the formula (7) represents an integer of 1 to 3. [Inventive effect]

According to the present invention, it is possible to provide a liquid crystal alignment film that is excellent in rubbing resistance, has a desired voltage holding ratio, and has reliability even if the liquid crystal alignment film obtained by the low-temperature firing process. Moreover, according to the present invention, in addition to the above-mentioned effects, a liquid crystal alignment agent for forming the liquid crystal alignment film, and a liquid crystal display element provided with the liquid crystal alignment film can be provided. Furthermore, according to the present invention, in addition to the above-mentioned effects, or in addition to the above-mentioned effects, a method for producing the above-mentioned liquid crystal alignment film can be provided. [Form of implementing the invention]

This case provides a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element provided with the liquid crystal alignment film. The following descriptions are performed in order. <Liquid crystal alignment agent> The liquid crystal alignment agent of the present application contains (A) component; (B) component; and (C) component. <<component (A)>> The component (A) is at least one selected from the group consisting of a polyimide precursor and a polyimide obtained by an imidization reaction of the polyimide precursor. kind of polymer. [Polyamic acid] The polyamic acid of the present invention can be obtained by reacting a diamine compound with a tetracarboxylic dianhydride.

<Diamine> The diamine used for the polymerization of the polyamic acid of the present invention can be represented by the following formula (1).

A ₁ and A ₂ of the above formula (1) are each independently, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and an alkynyl group having 2 to 5 carbon atoms, and Y ₁ is divalent organic base. From the viewpoint of liquid crystal alignment, A ₁ and A ₂ are preferably a hydrogen atom or a methyl group. In a preferred aspect of the formula (2), the diamine of the following formula (DA-1) can be used. In addition, in the above formula (DA-1), Y _d may be a divalent organic group represented by the following formulae (Y-1) to (Y-171).

In formula (Y-87), X ¹ is a sulfur atom, an oxygen atom or -NH-, R ⁸ and R ⁹ are each independently a divalent organic group, at least one of R ⁸ and R ⁹ has an aromatic ring, "- The bonding bond of at least one of CO-X ¹ -" is bonded to an aromatic ring, preferably the formula (b- 1)~(b-42) compounds, which are obtained by removing two amine groups.

In formula (Y-139), R ₁ and R ₂ are each ethylidene, -COO-, -OCO-, -NHCO-, and -N(CH ₃ )CO-.

In the above formula, n is an integer of 1 to 6. Among the above-mentioned diamines, from the viewpoint of the solubility of the polyimide precursor or the polyimide obtained by the imidization of the polyimide precursor to the solvent, Y-1 to Y-6 are preferred. , Y-8, Y-9, Y-14~Y-17, Y-20, Y-26~Y-28, Y-32, Y-38~Y-42, Y-49~Y-60, Y -64~Y-69, Y-72, Y-77, Y-84, Y-86, Y-156, Y-160~Y-163, Y-165, more preferably Y-8, Y-9, Y-14, Y-16, Y-17, Y-20, Y-26~28, Y-32, Y-38, Y-68, Y-72, Y-77, Y-84, Y-160, Y-161, Y-165.

A preferable aspect of one of the diamines usable in the present invention includes diamines having an alkyl group and a fluorine-containing alkyl group in a side chain represented by the following formulae [Sd-1] to [Sd-4].

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.

Another preferable aspect of the diamine that can be used in the present invention includes 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 Phenyl-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'-diaminodiphenyl Ethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-di A carboxylic acid, and a diamine having a structure represented by the following formulae [4a-1] to [4a-6]. The above-mentioned diamine is preferably used in combination with a diamine that imparts vertical alignment, which will be described later, from the viewpoint of improving the curing rate of the liquid crystal alignment film. These diamines are preferably 10 mol % or more, more preferably 20 mol % or more with respect to the entire diamine component used in the liquid crystal aligning agent.

Another preferable aspect of the diamine that can be used in the present invention includes diamines represented by the following formulae [2a-1] to [2a-9] (n each independently represents an integer of 2 to 12).

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

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- , Q1 is a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, X ₂ is a single bond, or at least one selected from the group consisting of aliphatic hydrocarbon groups with 1 to 20 carbon atoms, non-aromatic cyclic hydrocarbon groups, and aromatic hydrocarbon groups One type of divalent organic group, X ₃ is a single bond, or selected from -O-, -NQ2-, -CONQ2-, -NQ2CO-, -COO-, -OCO-, and -O(CH ₂ )m- (m is an integer of 1 to 5) a divalent organic group of at least one type, Q2 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, _X4 is a nitrogen-containing aromatic heterocyclic ring, and n is 1 The integer to 4 is preferably the combination described in Tables 1 to 3 of paragraphs [0036] to [0038] of International Publication WO2009/093707.

Another preferable aspect 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).

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

In the above formula (2A) and the above formula (2B), R represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms (although any hydrogen atom thereof may be substituted by a fluorine atom), or an alkane having 1 to 18 carbon atoms Oxygen (but any of its hydrogen atoms may be replaced by fluorine atoms). A and B each independently represent a single bond or any ring structure represented by the following formula. However, any hydrogen atom in the ring structure may be substituted by 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.

When imparting vertical alignment, diamines that can be used in the present invention include the second representations of formulas [2-1] to [2-31] described in paragraphs [0033] to [0042] of International Publication WO2013/125595 Amines, etc., are preferably 5 mol % or more, more preferably 10 mol % or more, and still more preferably 20 mol % or more with respect to the whole diamine component. From the viewpoint of increasing the above-mentioned hardening rate, it is preferably 90 mol % or less, more preferably 80 mol % or less. More preferable diamines are at least one selected from the following formulae [2a-24] to [2a-33].

In the formula (2a-32), when it is an ortho position with respect to one amine group, each of R ¹ independently represents a group selected from -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ - and -CH ₂ When at least one bonding group of OCO- is in the meta position with respect to the two amine groups, R ¹ represents the group selected from -CONH-, -NHCO-, and -CH ₂ in addition to the bonding groups shown above. - at least one bonding group, R ² each independently represents a linear or branched alkyl group with 1 to 22 carbon atoms, a linear or branched alkoxy group with 1 to 22 carbon atoms, and Cy is selected from the group consisting of Base of 4,4'-biphenyldiyl, 4,4'-phenylcyclohexyl and 4,4'-dicyclohexyl.

In the above formula, R ₃ represents -O- or -CH ₂ O-, Cy2 is synonymous with the aforementioned Cy, R ⁷ each independently represents a straight-chain or branched alkyl group with 3 to 12 carbon atoms, 1,4-extended Cis-trans isomers of cyclohexyl represent trans isomers. Moreover, 4-(2-(methylamino)ethyl)aniline or the diamine described in Unexamined-Japanese-Patent No. 2010-97188 can also be used other than the diamine mentioned above. Among the above-mentioned photoreactive diamines, the following compounds are preferred from the viewpoint of photoreactivity and the like.

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

<Tetracarboxylic dianhydride> The tetracarboxylic dianhydride includes, for example, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples of these include the following groups of [1] to [5], etc., respectively.

[1] Aliphatic tetracarboxylic dianhydride, such as 1,2,3,4-butane tetracarboxylic dianhydride, etc.; [2] Alicyclic tetracarboxylic dianhydride, such as the following formula (X1-1) ~(X1-13) (In formulae (X1-1)~(X1-4), R ₃ to R ₂₃ are each independently a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, and a group with 2 to 6 carbon atoms. Alkenyl group, alkynyl group with 2 to 6 carbon atoms, monovalent organic group with 1 to 6 carbon atoms containing fluorine atom, or phenyl group, which may be the same or different, in the above formula, R _M is a hydrogen atom or a methyl group , Xa is an acid dianhydride such as the tetravalent organic group represented by the following formulas (Xa-1)~(Xa-7);

[3] 1,2,4,5-cyclohexanetetracarboxylic 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-dianhydride, 4,9-dioxatricyclo[ 5.3.1.02,6]Undecane-3,5,8,10-tetraone, etc.;

[4] Aromatic tetracarboxylic dianhydrides such as pyromellitic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3',4,4'-diphenylene Base tetracarboxylic dianhydride, acid dianhydrides represented by the following formulae (Xb-1) to (Xb-10), etc.; and

[5] In addition, acid dianhydrides represented by formulae (X1-44) to (X1-52) and tetracarboxylic dianhydrides described in JP-A-2010-97188 can be mentioned.

Moreover, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types. Among the above-mentioned acid dianhydrides, from the viewpoint of the solubility of the polyimide precursor or the polyimide obtained by imidizing the polyimide precursor to the solvent, X1-1~X1 are preferred. -3, X1-5~X1-12, Xa-1~Xa-3, Xb-13, X6~X8, Xb-1, Xb-7~Xb-9, Xb-13, X1-44, X1-47 ~X1-52, more preferably X1-1~X1-3, X1-5~X1-12, Xa-1~Xa-3, Xb-7~Xb-9, X1-44, X1-49.

<Method for Producing Polyamic Acid> The polyamic acid used in the present invention can be synthesized by a known method (for example, refer to International Publication WO2014/034792).

The organic solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone in terms of the solubility of the monomer and polymer, which can be Use 1 type or mix 2 or more types. The concentration of the polymer is preferably 1 to 30 mass %, more preferably 5 to 20 mass %, from the viewpoint that the polymer is not easily precipitated and a high molecular weight body can be obtained.

[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 can be synthesized from the following (1) polyamic acid and (2) tetracarboxylic acid diester and diamine. In the case of amine ester or (3) in the case of synthesis by reaction of tetracarboxylic acid diester dichloride and diamine, it is synthesized by a conventional method (for example, refer to International Publication WO2014/034792).

The above-mentioned tetracarboxylic acid diester can be represented by 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 above-mentioned tetracarboxylic dianhydride), so that the above-mentioned tetracarboxylic acid can be The carboxylic dianhydride is produced by a known method (for example, refer to International Publication No. 2010/092989) of reacting a carboxylic acid dianhydride with an alcohol having 1 to 5 carbon atoms represented by R ¹ OH.

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

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

From the viewpoint of obtaining a high-molecular-weight and low-dispersion polyamide, the tetracarboxylic acid diester dichloride is preferably the formula [5-Cl] (in the above formula (5-Cl), A is the same as the above formula ( 5) A compound represented by the synonym of A).

The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the viewpoint of the solubility of the polyamide, and these can be used alone or in combination of two or more. The polymer concentration at the time of synthesis is preferably 1 to 30 mass %, more preferably 5 to 20 mass %, from the viewpoint that the polymer is not easily precipitated and a high molecular weight body can be obtained.

Among the above-mentioned three methods for synthesizing a polyamic acid ester, since a high molecular weight polyamic acid ester can be obtained, the above-mentioned synthesis method (2) or the above-mentioned (3) is particularly preferred. [Polyimide] The polyimide used in the present invention can be obtained by a known method (for example, refer to International Publication WO2013/125595).

The above-mentioned polyimide may be a complete imide compound in which all the amide structures of polyamides or the amide structures of polyamides have undergone dehydration and ring closure, or only amides may be used. A partial imide compound in which a part of the amide acid or amide structure is dehydrated and ring-closed, and the amide structure or amide structure and the amide ring structure coexist. The polyimide used has an imidization ratio of preferably 20% or more, and is preferably 90% or less, more preferably 60% or less, from the viewpoint of securing solubility in a solvent. This imidization rate is the ratio of the number of imide ring structures to the sum of the number of imide structures or imide ester structures of polyimide and the number of imine ring structures, and is expressed as percentile. Here, a part of the imide ring may be an isoimide ring.

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

According to a more preferred aspect of the present invention, the component (A) is derived from at least one tetracarboxylic acid selected from the group consisting of tetracarboxylic dianhydride, tetracarboxylic diester, and tetracarboxylic diester dichloride. A polymer obtained by reacting a compound with a diamine. In this case, the tetracarboxylic dianhydride, the tetracarboxylic diester, and the tetracarboxylic diester dichloride preferably include those selected from the group consisting of the aforementioned aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic A structure of at least one of the group of tetracarboxylic dianhydrides, and these tetracarboxylic diesters and tetracarboxylic diester dichlorides. Still more preferably, it includes at least one structure 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 the solubility of the solvent, the preferred formula (X1- 1)~(X1-3), (X1-6)~(X1-12), (Xa-1)~(Xa-2), pyromellitic anhydride, 4,4'-(hexafluoroisopropylene) base) diphthalic anhydride, (Xb-6)~(Xb-8), (X1-44), (X1-47)~(X1-52), more preferably (X1-1)~(X1 -3), (X1-6)~(X1-12), (Xa-1)~(Xa-2), (Xb-6)~(Xb-8), (X1-44), (X1-49 ).

A more preferable form of the aforementioned tetracarboxylic acid derivative comprises a compound selected from the group consisting of compounds represented by the following formulae (X1-1-1) to (X1-1-6),

To contain a compound selected from the group consisting of compounds represented by the above-mentioned formulas (X1-6) to (X1-9), 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetrakis Carboxylic dianhydride, pyromellitic anhydride, compounds represented by (Xb-6), and at least one compound (T) of the group consisting of these tetracarboxylic acid diesters and tetracarboxylic acid diester dichlorides are special good.

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

The molecular weight of the polyamic acid, polyamic acid ester and polyimide described in the present invention, in terms of weight average molecular weight, is preferably 2,000-500,000, more preferably 5,000-300,000, still more preferably 10,000-100,000. Also, 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.

<<The amount of component (A)>> When the total amount of component (A) is 100% by weight of the liquid crystal aligning agent, it can be 1 to 15% by weight, preferably 1 to 8% by weight, more preferably 1.5% by weight ~7 wt%.

<(B) component> The liquid crystal aligning agent of this case contains (B) component. (B) component is a compound represented by following formula (N-1). In formula (N-1), R ¹ and R ² represent the same or different, straight-chain or branched alkylene groups with 1 to 10 carbon atoms, or cycloalkylene groups with 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 ethers and tertiary amines. In addition, the alkylene group may be a saturated or unsaturated alkylene group. R ¹ and R ² may be straight-chain alkylene with 1-10 carbon atoms, preferably 1-5, and particularly preferably saturated straight-chain alkylene with 1-2 carbon atoms.

R ³ and R ⁴ represent the same or different, a hydrogen atom, or a linear or branched alkyl group having 1 to 20 carbon atoms. The alkyl group may have at least one group selected from the group consisting of ethers and tertiary amines. In addition, the alkyl group may be a saturated or unsaturated alkyl group. R ³ and R ⁴ may be 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. Between the carbon-carbon bonds in the aliphatic hydrocarbon group, any one of a cycloalkyl group having 3 to 12 carbon atoms, an aromatic hydrocarbon group having a carbon number of 5 to 12, (thio)ether, carbonyl group and tertiary amine can be inserted , the aliphatic hydrocarbon group may have a group selected from epoxy group and halogen. Between the carbon-carbon bonds in the alicyclic hydrocarbon group, any one of (thio)ether, carbonyl, and tertiary amine can be inserted, and one of the single bonds that do not form a ring can be replaced by an alkylene having 1 to 12 carbon atoms. base substitution. z is an integer from 1 to 6.

The cycloalkyl group having 3 to 12 carbon atoms in R ⁵ can be selected from any of cyclopropane, cyclobutane, cyclopentane, cyclohexane, cyclohexene, norbornane, and adamantane, and 2 hydrogen atoms are removed. And get the base.

The aromatic hydrocarbon group of R ⁵ having 5 to 12 carbon atoms can be exemplified by any one of benzene, biphenyl, pyridine, pyrazine, naphthalene, furan, imidazole, oxazole, thiazole and furan, obtained by removing two hydrogen atoms base.

The alkylene group having 1 to 12 carbon atoms in R ⁵ includes methylidene, ethylidene, propylidene, butylene, pentylidene, hexylidene, heptylidene, octylidene, nonylidene, Decenyl, undecenyl, dodecenyl, vinylidene, propenylene, butenyl, pentenyl, ethynyl, propynyl and the like.

When z is 1, and R ⁵ is a monovalent aliphatic hydrocarbon group having 1 to 24 carbon atoms, R ⁵ includes an alkyl group having 1 to 24 carbon atoms, an alkenyl group having 2 to 24 carbon atoms, and an alkyl group having 2 to 24 carbon atoms. alkynyl. When z is 2 or more, and R ⁵ is an aliphatic hydrocarbon group having 2 or more valences and having 1 to 24 carbon atoms, R ⁵ can be selected from the aforementioned monovalent aliphatic hydrocarbon group having 1 to 24 carbon atoms, and z-1 hydrogen atom is removed. , and become the bonder. When z is 1 and R ⁵ is a monovalent alicyclic hydrocarbon group having 3 to 24 carbon atoms, R ⁵ includes a monovalent group such as a cycloalkyl group, a cyclodecahydronaphthyl group, and an adamantyl group. When z is 2 or more and R ⁵ is an alicyclic hydrocarbon group having a valence of 2 or more, R ⁵ may be selected from the aforementioned monovalent alicyclic hydrocarbon group having 3 to 24 carbon atoms, and z-1 hydrogen atoms are removed to form a bond. keyer.

The compound represented by the formula (N-1) is preferably an epoxy compound having a structure represented by the following formulae (N-2-1) to (N-2-4).

In (N-2-1) to (N-2-4), X each independently represents a single bond, methylidene, ethylidene, propylidene, butylene, pentylene, and hexylene. Y represents any one of methylidene, ethylidene, propylidene, vinylidene, oxy, and thio. Z represents cyclopentanediyl, cyclohexanediyl, or norbornediyl.

The compound represented by the formula (N-1) is represented by the following formulas (N-3-1) to (N-3-4), or 1,3-bis(diepoxypropylaminomethyl)cyclohexane, 1,4-Bis(diglycidylaminomethyl)cyclohexane, 2,5-bis(diglycidylaminomethyl)norbornane, 2,6-bis(diglycidyl) aminoaminomethyl) norbornane is preferred.

<<The amount of the component (B)>> In the liquid crystal aligning agent of the present case, the component (B) may be 1 to 30% by weight relative to 100% by weight of the (A) component, preferably 2 to 20% by weight, more Preferably it is 2 to 15 weight%, More preferably, it is 2 to 10 weight%.

<(C)component> The liquid crystal aligning agent of this case contains at least 1 sort(s) of specific solvent chosen from the group of following formula (1)-(8) as (C)component. In formulae (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 formulae (5) and (6), R ¹⁷ to R ¹⁹ represent an alkyl group having 1 or 2 carbon atoms. n in the formula (7) represents an integer of 1 to 3.

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

<<Components other than (A) components to (C) components>> The liquid crystal aligning agent of the present invention may optionally contain components other than the above-mentioned (A) components to (C) components as appropriate. For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, 1,3-dimethylimidazolidinone, N,N-dimethylformamide, N ,N-dimethylacetamide, dimethylsulfoxide, ethanol, isopropanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butanol, 1-pentanol, 2-pentanol alcohol, 3-pentanol, 2-methyl-1-butanol, isoamyl alcohol, tert-pentanol, 3-methyl-2-butanol, neopentanol, 1-hexanol, 2-methyl- 1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2-ethylene glycol, 1,2- Propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2- Methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, 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, diethyl acetate Glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol Monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxy propionate, methyl ethyl 3-ethoxy propionate, ethyl 3-methoxy propionate, 3-ethoxy Propionic acid, 3-methoxypropionic acid, 3-methoxypropionate, 3-methoxypropionate, 3-methoxypropionate, 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate Esters, isoamyl lactate, and organic solvents of the following structures, but not limited to these.

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, a-38, more preferably a-22, a-37.

<Other crosslinkable compounds> The components other than the components (A) to (C) include crosslinkable compounds. The crosslinkable compound includes, for example, a crosslinkable compound having an epoxy group, an isocyanate group, an oxetanyl group or a cyclocarbonate group, a crosslinkable compound having a group selected from a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group. A crosslinkable compound having at least one substituent in a group, or a crosslinkable compound having a polymerizable unsaturated bond, is not limited to these. In addition, these substituents or polymerizable unsaturated bonds may have two or more in the crosslinkable compound.

Examples of crosslinkable compounds having epoxy groups or isocyanate groups include bisphenol acetone glycidyl ether, phenol novolak epoxy resin, cresol novolak epoxy resin, and triglycidyl isocyanurate. , tetraglycidylamino diphenylene, tetraphenylglycidyl ether ethane, triphenylglycidyl ether ethane, bisphenol hexafluoroacetyl diglycidyl ether, 1,3-bis (1-(2,3-Epoxypropoxy)-1-trifluoromethyl-2,2,2-trifluoromethyl)benzene, 4,4-bis(2,3-epoxypropyl) oxy) 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-epoxy) Propoxy)phenyl)-1-(4-(1-(4-(2,3-epoxypropoxy)phenyl)-1-methylethyl)phenyl)ethyl)phenoxy base)-2-propanol, etc.

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

Specifically, the crosslinkable compound represented by the formula [4a] to the formula [4k] disclosed in International Publication No. WO2011/132751 (published on October 27, 2011) may be mentioned on pages 58 to 59.

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

Specifically, the crosslinkable compound represented by the formula [5-1] to the formula [5-42] described in International Publication No. WO2012/014898 (published on February 2, 2012), pages 76 to 82, can be mentioned.

The crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group and an alkoxy group includes, for example, an amine-based resin having a hydroxyl group or an alkoxy group, for example, a melamine resin, a urea resin, a guanamine resin, Glycoluril-formaldehyde resin, succinimide-formaldehyde resin or ethylene urea-formaldehyde resin, etc. Specifically, a melamine derivative, a benzoguanamine derivative, or a glycoluril in which the hydrogen atom of the amine group is substituted with a methylol group or an alkoxymethyl group or both can be used. The melamine derivative or benzoguanamine derivative may also exist as a dimer or trimer. These are preferably those having an average of 3 or more and 6 or less hydroxymethyl groups or alkoxymethyl groups per triazine ring.

Examples of the above-mentioned melamine derivatives or benzoguanamine derivatives include commercially available MX-750 substituted by 3.7 methoxymethyl groups per triazine ring on average, and MX-750 substituted by an average of 5.8 per triazine ring per triazine ring. MW-30 (the above are manufactured by Sanwa Chemical Co., Ltd.) substituted with methoxymethyl group or methoxymethylated melamine such as Cymel300, 301, 303, 350, 370, 771, 325, 327, 703, 712, etc. Cymel235, 236, 238, 212, 253, 254, etc. methoxymethylated butoxymethylated melamine, Cymel506, 508, etc., butoxymethylated melamine, such as Cymel1141, carboxyl-containing methoxymethyl melamine Isobutoxymethylated melamine, methoxymethylated ethoxymethylated benzoguanamine such as Cymel1123, methoxymethylated butoxymethylated benzoguanamine such as Cymel1123-10 , Such as Cymel1128 butoxymethylated benzoguanamine, such as Cymel1125-80 containing carboxyl methoxymethylated ethoxymethylated benzoguanamine (the above are manufactured by Mitsui Cyanamid Corporation). Moreover, examples of glycoluril include butoxymethylated glycoluril such as Cymel1170, methylolated glycoluril such as Cymel1172, and the like, and methoxymethylolated glycoluril such as Powderlink1174.

Examples of benzene or phenolic compounds having a hydroxyl group or alkoxy group include 1,3,5-paras(methoxymethyl)benzene, 1,2,4-paras(isopropoxymethyl)benzene, 1,3,5-paras(methoxymethyl)benzene, ,4-bis(sec-butoxymethyl)benzene or 2,6-dihydroxymethyl-p-tert-butylphenol. More specifically, the crosslinkable compounds of formula [6-1] to formula [6-48] disclosed in International Publication No. WO2011/132751 (published on October 27, 2011), pages 62 to 66, can be mentioned.

Crosslinkable compounds having a polymerizable unsaturated bond include, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, tri(meth)acrylate A crosslinkable compound having three polymerizable unsaturated groups in the molecule, such as meth)acryloyloxyethoxytrimethylolpropane or glycerol polyglycidyl ether poly(meth)acrylate, etc., and Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate Meth)acrylate, polypropylene glycol di(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide bisphenol A di(meth)acrylate base) acrylate, propylene oxide bisphenol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, glycerol di(meth)acrylate, pentaerythritol di(meth)acrylate ) acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, diglycidyl phthalate di(meth)acrylate ) crosslinkable compounds having two polymerizable unsaturated groups in the molecule, such as acrylate or hydroxypivalate neopentyl glycol di(meth)acrylate, and 2-hydroxyethyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-(meth)acrylonitrile Oxy-2-hydroxypropylphthalate, 3-chloro-2-hydroxypropyl(meth)acrylate, glycerol mono(meth)acrylate, 2-(meth)acryloyloxy A crosslinkable compound etc. which have one polymerizable unsaturated group in a molecule|numerator, such as ethyl ethyl phosphate, N-methylol (meth)acrylamide, etc.

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

In formula [7A], E ₁ represents a group selected from the group consisting of cyclohexane ring, bicyclohexane ring, benzene ring, biphenyl ring, terphenyl ring, naphthalene ring, perylene ring, anthracene ring or 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.

An example of the above-mentioned crosslinkable compound is not limited to these. Moreover, the crosslinkable compound used for the liquid crystal aligning agent of this invention may be 1 type or a combination of 2 or more types may be sufficient as it.

The content of the crosslinkable compound in the liquid crystal aligning agent of the present invention is preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of all the polymer components. Among them, in order to carry out the crosslinking reaction and exhibit the intended effect, it is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the total polymer components. More preferably, it is 1-50 mass parts.

<Other optional components> In the liquid crystal aligning agent of the present invention, a compound that improves the uniformity of the film thickness or the surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied can be used within a range that does not impair the effects of the present invention. Compounds that improve the uniformity of the film thickness or the surface smoothness of the liquid crystal alignment film include fluorine-based surfactants, polysiloxane-based surfactants, and nonionic surfactants. Specific examples of these include the surfactants described in paragraph [0117] of International Publication WO2016/047771. More specifically, for example, F-Top EF301, EF303, EF352 (the above are manufactured by TOHKEM PRODUCTS), MegafacF171, F173, R-30 (the above are manufactured by Dainippon Ink Co., Ltd.), Fluorad FC430, FC431 (the above are Sumitomo 3M) Company), AsahiguardAG710, SurflonS-382, SC101, SC102, SC103, SC104, SC105, SC106 (the above are manufactured by Asahi Glass Co., Ltd.), etc. The usage amount of the surfactant is based on 100 parts by mass of all the polymer components contained in the liquid crystal alignment agent, preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass.

In addition, as a compound that promotes the transfer of electric charges in the liquid crystal alignment film and promotes the disappearance of the electric charge of the element, the compounds described in pages 69 to 73 of International Publication No. WO2011/132751 (published on October 27, 2011) may also be added to the liquid crystal alignment agent. [M1] ~ the nitrogen-containing heterocyclic amine compound represented by the formula [M156]. The amine compound can also be directly added to the liquid crystal aligning agent, but it is preferably added after adjusting to a solution with a concentration of 0.1 to 10 mass %, preferably 1 to 7 mass %. This solvent is not particularly limited as long as it dissolves the specific polymer (A).

In the liquid crystal aligning agent of the present invention, in addition to the above-mentioned weak solvent, cross-linking compound, resin film or compound for improving the uniformity of the film thickness or surface smoothness of the liquid crystal alignment film, and the compound for promoting the disappearance of electric charges, the present invention is not damaged. In the range of the effect of the invention, polymers other than the polymers described in the present invention, silane coupling agents for the purpose of improving the adhesion between the alignment film and the substrate, and polyimide precursors may be added when the coating film is fired. An imidization accelerator for the purpose of efficiently carrying out imidization by heating, etc.

The liquid crystal aligning agent of this case has the form of the solution containing the said (A) component - (C) component. The liquid crystal alignment agent used in the present invention is in the form of a solution in which a polymer with 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 by setting the thickness of the coating film to be formed, but from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by weight or more. From the viewpoint of storage stability of the solution, it is preferably 10% by weight or less.

The liquid crystal aligning agent of this case can be appropriately changed by setting the thickness of the coating film formed by the solid content concentration (the ratio of the total weight of the components other than the component (C) of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent), However, from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by weight or more, and from the viewpoint of the storage stability of the solution, it is preferably 10% by weight or less.

The range of the particularly preferable solid content concentration varies depending on the method of coating the liquid crystal aligning agent on the substrate. For example, when using the spin coater method, the concentration of the polymer is preferably in the range of 1.5 to 4.5% by weight. In the printing method, the solid content concentration is in the range of 3 to 9 wt %, whereby the solution viscosity is in the range of 12 to 50 mPa·s. In the case of the ink jet method, the solid content concentration is set in the range of 1 to 5 wt %, whereby the solution viscosity is set in the range of 3 to 15 mPa·s. The molecular weight of the polyimide precursor and polyimide of the component (A) in this case is weight average molecular weight, preferably 2,000-500,000, more preferably 5,000-300,000, still more preferably 10,000-100,000. Also, 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 alignment agent of the present invention can be provided.

Furthermore, according to another aspect of the present invention, a method for producing a liquid crystal alignment film can be provided, which comprises the following steps: coating the liquid crystal alignment agent of the present invention on a substrate, forming a coating film, and the aforementioned coating The step of irradiating the coating film with light is performed in a state where the film is not in contact with the liquid crystal layer or in a state in which it is in contact with the liquid crystal layer.

Moreover, according to another aspect of this invention, the liquid crystal display element provided with the liquid crystal alignment film of this invention, or the liquid crystal alignment film obtained by the said manufacturing method of this invention can be provided. Details are as follows.

<Liquid crystal alignment film·liquid crystal display element> By using the above-mentioned liquid crystal alignment agent, a liquid crystal alignment film can be produced. Moreover, the liquid crystal display element of 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 element of the present invention is not particularly limited, for example, it can be applied to TN (Twisted Nematic) type, STN type, vertical alignment type (including VA-MVA type, VA-PVA type, etc.), in-plane switching type (IPS type) Type), FFS (Fringe Field Switching) type, optically compensated bending mode (Optically Compensated Bend: OCB type) and other various operation modes.

The liquid crystal display element of the present invention can be produced, for example, by the steps including the following steps (1-1) to (1-3). The step (1-1) uses different substrates depending on the desired operation mode. Step (1-2) and step (1-3) are common to each operation mode.

[Step (1-1): Formation of Coating Film] First, the liquid crystal aligning agent of the present invention is coated on a substrate, and then a coating film can be formed on the substrate by heating the coated surface. (1-1A) For example, when a TN type, STN type, or VA type liquid crystal display element is produced, first, two substrates on which patterned transparent conductive films are provided are paired, and each transparent conductive film is formed on the surface of the pair. It is preferable to apply the liquid crystal alignment agent prepared above by a lithographic method, a spin coating method, a roll coater method or an inkjet printing method, respectively. For the substrate, for example, glass such as floating glass, soda lime glass, etc. can be used; A transparent substrate made of plastic. For the transparent conductive film provided on one surface of the substrate, a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), a film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) can be used. Into the ITO film and so on. In order to obtain a patterned transparent conductive film, for example, after forming an unpatterned transparent conductive film, a method of forming a pattern by photo-etching can be used; when forming a transparent conductive film, a film having a desired pattern is used. methods of masking; etc. During the coating of the liquid crystal alignment agent, in order to make the surface of the substrate and the transparent conductive film and the coating film better, in the surface of the substrate, the surface of the coating film can be pre-coated with functional silane compounds, functional Pre-treatment of titanium compounds, etc.

After the liquid crystal alignment agent is applied, it is preferable to perform preheating (prebaking) for the purpose of preventing the liquid sag of the applied liquid crystal alignment agent. The pre-baking temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The pre-baking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, after the solvent is completely removed, if necessary, a firing (post-baking) step may be performed for the purpose of thermal imidization of the amide acid structure present in the polymer. The firing temperature (post-baking temperature) at this time is preferably 80 to 300°C, more preferably 120 to 250°C. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The thickness of the film thus formed 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 element, the electrode formation surface of the substrate on which the electrode formed by the patterned transparent conductive film or the metal film is provided, and the electrode is not provided. One surface of the opposite substrate is coated with a liquid crystal alignment agent, and then each coated surface is heated to form a coating film. At this time, the material of the substrate and the transparent conductive film used, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the formed coating film , as in (1-1A) above. As the metal film, for example, a film made of a metal such as chromium can be used.

In the case of any one of the above (1-1A) and (1-1B), a liquid crystal alignment film or a coating film to be a liquid crystal alignment film can be formed by removing the organic solvent after coating the liquid crystal alignment agent on the substrate. At this time, after the coating film is formed, the polyamic acid, polyamic acid ester and polyimide prepared in the liquid crystal aligning agent of the present invention are subjected to dehydration and ring-closure reaction by reheating. Aminated coating.

[Step (1-2): Treatment for imparting alignment energy] When manufacturing TN type, STN type, IPS type or FFS type liquid crystal display elements, the coating film formed in the above step (1-1) is subjected to imparting alignment energy to the liquid crystal. processing. Thereby, the alignment of the liquid crystal molecules can be imparted to the coating film, and the liquid crystal alignment film is formed. The treatment for imparting alignment energy includes, for example, a roller wound with a cloth made of nylon, rayon, cotton, etc. fibers, a rubbing treatment of wiping the coating film in a certain direction, and irradiation of polarized or non-polarized radiation to the coating film. photo-alignment processing, etc. In addition, when manufacturing a VA type liquid crystal display element, the coating film formed by the above-mentioned step (1-1) can be used as a liquid crystal alignment film as it is, but the coating film can also be subjected to a treatment for imparting alignment energy.

When the liquid crystal alignment energy is imparted to the coating film by the photo-alignment treatment, the radiation irradiated to the coating film can be, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. In addition, when the radiation used is linearly polarized light or partially polarized light, it may be irradiated in a direction perpendicular to the substrate surface, or in an oblique direction, or may be irradiated in combination. When irradiating non-polarized radiation, the direction of irradiation is oblique. As the light source to be 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 or the like can be used. Ultraviolet rays in a preferable wavelength range can be obtained by means of combining a light source with a filter, a diffraction grating, or the like, for example. The radiation dose is preferably 10 to 5,000 mJ/cm ² , more preferably 30 to 2,000 mJ/cm ² . In addition, the light irradiation to the coating film may be performed while heating the coating film in order to improve the reactivity. The temperature during heating is usually 30 to 250°C, preferably 40 to 200°C, and more preferably 50 to 150°C. Moreover, when using the ultraviolet-ray containing the wavelength light of 150-800nm, the light irradiation film obtained by the said process can be used as a liquid crystal alignment film as it is, but this light irradiation film can also 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, more preferably 10 to 100 minutes. The photo-alignment treatment here corresponds to the treatment of light irradiation in a state not in contact with the liquid crystal layer.

In addition, for the liquid crystal alignment film after rubbing treatment, by irradiating a part of the liquid crystal alignment film with ultraviolet rays, the pretilt angle of the area of a part of the liquid crystal alignment film is changed, or after forming a resist film on a part of the surface of the liquid crystal alignment film , After rubbing treatment in a different direction from the previous rubbing treatment, the treatment of removing the resist film is carried out, and the liquid crystal alignment film can also have different liquid crystal alignment energy in each area. In this case, the field of view characteristics of the obtained liquid crystal display element can be improved. The liquid crystal alignment film suitable for a VA type liquid crystal display element can also be suitable for a PSA (Polymer sustained alignment) type liquid crystal display element.

[Step (1-3): Construction of Liquid Crystal Cells] (1-3A) Two substrates on which the liquid crystal alignment films are formed as described above are prepared, and liquid crystal cells are produced by arranging liquid crystals between the two substrates arranged to face each other. When manufacturing a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method. First, the respective liquid crystal alignment films are made to face each other, and the two substrates are arranged to face each other through a gap (liquid crystal layer gap). Inside, after filling the liquid crystal, the injection hole is closed to manufacture the liquid crystal cell. The second method is called the ODF (One Drop Fill) method. In a specific place on one of the two substrates formed with the liquid crystal alignment film, such as coating a UV-curable sealant, and then dripping liquid crystal on a specific number of places on the surface of the liquid crystal alignment film, the liquid crystal alignment film will In the orientation method, the liquid crystal is expanded to the whole surface of the substrate while being bonded to another substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant to manufacture a liquid crystal cell. Regardless of the method used, the liquid crystal cell produced as described above is preferably reheated to a temperature at which the liquid crystal to be used becomes an isotropic phase, and then slowly cooled to room temperature to remove the flow alignment during liquid crystal filling.

As the sealant, for example, epoxy resin containing a hardener and alumina balls as spacers can be used. The liquid crystals include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred, for example, Schiff base liquid crystals, azoxy liquid crystals, Benzene-based liquid crystal, phenylcyclohexane-based liquid crystal, ester-based liquid crystal, terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal , Cubicane (cubane) liquid crystal and so on. In addition, cholesteric liquid crystals such as cholestery chloride, cholesteryl nonanoate, cholesteryl carbonate, etc. can also be added to these liquid crystals; Chiral agent sold under the trade names "C-15" and "CB-15" (manufactured by Merck); p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate Such as ferroelectric liquid crystal and so on. The liquid crystal may additionally contain an anisotropic dye. The term "dye" refers to a substance that can absorb or deform light in at least a part or the whole range in the visible light range, for example, in the wavelength range of 400nm to 700nm, and the term "anisotropic dye" refers to at least a part of the aforementioned visible light range. Or a substance that can absorb light anisotropically in the whole range. By using the aforementioned dyes, the color perception of the liquid crystal cells can be adjusted. The kind of anisotropic dyes is not particularly limited, and for example, black dyes or color dyes can be used. The ratio of the anisotropic dye to the liquid crystal can be appropriately selected within the range that does not impair the intended physical properties. For example, the anisotropic dye can be contained in a ratio of 0.01 to 5 parts by weight relative to 100 parts by weight of the liquid crystal compound, but If necessary, the aforementioned ratio can be changed to an appropriate range.

(1-3B) When producing a PSA-type liquid crystal display element, a liquid crystal cell was constructed in the same manner as in the above (1-3A), except that the photopolymerizable compound was injected or dropped together with the liquid crystal. Then, the liquid crystal cell is irradiated in a state where a voltage is applied between the conductive films having a pair of substrates. Here, the applied voltage can be, for example, 5-50V DC or AC. Moreover, as the light to be irradiated, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used, but ultraviolet rays including light having a wavelength of 300 to 400 nm are preferable. As a light source for irradiating 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 or the like can be used. Moreover, the ultraviolet-ray of the said preferable wavelength range can be obtained by the means etc. which combine a light source with a filter, a diffraction grating, etc., for example. The irradiation amount of light is preferably 100 mJ/cm ² or more, less than 20,000 mJ/cm ² , more preferably 100 to 10,000 mJ/cm ² .

(1-3C) When a liquid crystal aligning agent containing a compound (polymer or additive) having a photopolymerizable group is used to form a coating film on a substrate, a liquid crystal cell can be constructed in the same manner as in the above (1-3A), and then, A method of manufacturing a liquid crystal display element by irradiating a liquid crystal cell with light in a state where a voltage is applied between conductive films having a pair of substrates. According to this method, the advantages of the PSA mode can be realized with a small amount of light irradiation. The light irradiation to the liquid crystal cell may be performed in a state in which the liquid crystal is driven by applying a voltage, or may be performed in a state in which a low voltage such that the liquid crystal is not driven is applied. The applied voltage can be, for example, 0.1-30V DC or AC. As for the conditions for irradiating light, the description of the above (1-3B) can be applied. The light irradiation treatment here corresponds to the light irradiation treatment in the state of being in contact with the liquid crystal layer.

Moreover, the liquid crystal display element of this invention can be obtained by bonding a polarizing plate to the outer surface of a liquid crystal cell. The polarizing plate attached to the outer surface of the liquid crystal cell includes a polarizing film called "H film" that absorbs iodine while stretching and aligning polyvinyl alcohol, and a polarizing plate sandwiched by a cellulose acetate protective film. Or a polarizing plate made of H film.

The liquid crystal display element of the present invention can be applied to various devices, such as clocks, portable games, typewriters, notebook personal computers, car navigation systems, video recorders, PDAs, digital cameras, mobile phones, smart phones, various Various display devices such as monitors, LCD TVs, and information displays. As described above, by using the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal aligning film excellent in the uniformity of the film thickness within the coating surface, the linearity and dimensional stability of the coating peripheral portion. In addition, by using the liquid crystal aligning agent of the present invention, a liquid crystal aligning film having a desired voltage holding ratio, excellent rubbing resistance, and reliability can be obtained.

[Example]

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In the examples, the structures of the compounds used are shown below. <Tetracarboxylic dianhydride> CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic acid Anhydride PMDA: pyromellitic dianhydride TCA: 2,3,5-tricarboxycyclopentylacetic acid-1,4,2,3-dianhydride

<Diamine compound> p-PDA: p-phenylenediamine DBA: 3,5-diaminobenzoic acid PCH7: 1,3-diamino-4-[4-(trans-4-n-heptyl Cyclohexyl)phenoxy]benzene APC12: 1,3-diamino-4-(dodecyloxy)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 the component (B) used in the examples and the types of crosslinking agents used in the comparative examples are shown below.

The abbreviations of the organic solvents used in the examples and the like are shown below. NMP: N-methyl-2-pyrrolidone GBL: γ-butyl lactone BCS: butyl cellosolve CHN: cyclohexanone CPN: cyclopentanone PGME: propylene glycol monomethyl ether EC: ethyl carbitol DME: diethyl Glycol Dimethyl Ether

<Measurement of polymer molecular weight> For the molecular weight of the polymer in the synthesis example, a normal temperature gel permeation chromatography (GPC) apparatus (SSC-7200, manufactured by Shodex, KD-803, KD-805) manufactured by SENSHU SCIENTIFIC CO., LTD. was used. , as measured below. Column temperature: 50°C Elution solution: DMF (additive is lithium bromide-hydrate (LiBr·H ₂ O) at 30 mmol/L, phosphoric acid·anhydrous crystal (o-phosphoric acid) at 30 mmol/L, THF: 10 ml/L) Flow rate: 1.0 ml/min Calibration line preparation The company's polyethylene glycol (molecular weight about 12,000, 4,000, 1,000).

(Molecular weight measurement of polyimide) For the molecular weight of polyimide in the synthesis example, a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko), a column (KD-803, KD-805) (manufactured by Shodex), as measured below. Column temperature: 50℃ Eluent: N,N'-dimethylformamide (additive is lithium bromide-hydrate (LiBr‧H ₂ O) at 30 mmol/L, phosphoric acid‧anhydrous crystal (o-phosphoric acid) at 30 mmol/L 30 mmol/L, tetrahydrofuran (THF): 10 ml/L) Flow rate: 1.0 ml/min Calibration line preparation (manufactured by Polymer Laboratories) and polyethylene glycol (molecular weight about 12,000, 4,000, 1,000).

(Measurement of imidization rate) The imidization rate of the polyimide in the synthesis example was measured as follows. The polyimide powder (20 mg) was put into an NMR sample tube (NMR sampling tube stand φ5 (manufactured by Kusano)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) was added Mixture) (0.53ml), ultrasonically applied to dissolve completely. This solution was measured for proton NMR at 500 MHz using an NMR measuring machine (JNW-ECA500) (manufactured by JEOL Ltd.). The imidization rate is based on a proton derived from a structure that has not changed before and after imidization as a reference proton, and the peak product value of this proton and the proton peak derived from the NH group of imidic acid appearing in the vicinity of 9.5 ppm to 10.0 ppm are used. The integrated value is obtained by the following formula. Imidization rate (%)=(1-α‧x/y)×100 In the above formula, x is the cumulative peak value of protons derived from the NH group of amidic acid, y is the peak cumulative value of the reference proton, and α is The ratio of the number of reference protons to 1 NH proton in the polyamide acid (imidation rate of 0%).

[Synthesis of polyimide] <Synthesis example 1> BODA (18.8 g, 75 mmol), DBA (7.6 g, 50 mmol), PCH7 (21.7 g, 50 mmol) were mixed in NMP (148.0 g), and the mixture was heated at 80°C. After allowing to react for 5 hours, CBDA (4.8 g, 24 mmol) and NMP (63.5 g) were added, and the reaction was performed at 40°C for 12 hours to obtain a polyamic acid solution. NMP was added to this polyamic acid solution (50.0 g), and after diluting to 6 mass %, acetic anhydride (5.8 g) and pyridine (4.6 g) as imidization catalysts were added, and the reaction was carried out at 80° C. for 3 Hour. This reaction solution was put into methanol (600 ml), and the obtained precipitate was filtered and obtained. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain a polyimide powder (A). The imidization rate of this polyimide was 57%, the number average molecular weight was 17,800, and the weight average molecular weight was 53,400.

<Synthesis Example 2> BODA (12.5 g, 50 mmol), DBA (9.1 g, 60 mmol), PCH7 (15.2 g, 40 mmol) were mixed in NMP (147.6 g), and the reaction was carried out at 80°C for 5 hours, and then CBDA was added. (9.8 g, 50 mmol) and NMP (39.1 g) were reacted at 40° C. for 12 hours to obtain a polyamic acid solution. NMP was added to this polyamic acid solution (80.0 g), and after diluting to 6 mass %, acetic anhydride (15.4 g) and pyridine (8.9 g) as imidization catalysts were added, and the reaction was carried out at 50° C. for 3.5 Hour. This reaction solution was put into methanol (1000 ml), and the obtained precipitate was obtained by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain a polyimide powder (B). The imidization rate of this polyimide was 51%, the number average molecular weight was 20,100, and the weight average molecular weight was 68,100.

<Synthesis Example 3> BODA (18.8 g, 75 mmol), DBA (10.7 g, 70 mmol), and PBCH5 (13.0 g, 30 mmol) were mixed with NMP (132.2 g), and the reaction was carried out at 80°C for 5 hours, and then CBDA was added. (4.7 g, 24 mmol) and NMP (56.7 g) were 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 after diluting to 6 mass %, acetic anhydride (8.6 g) and pyridine (6.6 g) as imidization catalysts were added, and the reaction was carried out at 80° C. for 3.5 Hour. This reaction solution was put into methanol (650 ml), and the obtained precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain a polyimide powder (C). The imidization rate of this polyimide was 57%, the number average molecular weight was 18,500, and the weight average molecular weight was 52,700.

<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 allowed to react at room temperature for 1 hour. PMDA (16.8 g, 77 mmol) and NMP (103.3 g) were added, and the reaction was carried out at room temperature for 2 hours to obtain a polyamic acid solution (D). The number average molecular weight of this amide acid is 17200 and the weight average molecular weight is 62000.

<Synthesis Example 5> TCA (5.1 g, 22.9 mmol), DBA (2.5 g, 16.1 mmol), PCH7 (2.6 g, 6.9 mmol) were mixed in NMP (40.8 g), and the reaction was carried out at 60°C for 24 hours, A polyamide solution was obtained. To this polyamic acid solution (20.0 g), NMP was added, and after diluting to 6 mass %, acetic anhydride (2.3 g) and pyridine (1.8 g) as imidization catalysts were added, and the reaction was carried out at 90° C. 2 hours. This reaction solution was put into methanol (248 ml), and the obtained precipitate was obtained by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain a polyimide powder (E). The imidization 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 allowed to react at room temperature for 24 hours to obtain Polyamide solution (F). The number average molecular weight of this amide acid is 18700 and the weight average molecular weight is 56100.

<Examples 1 to 4> 1 g of 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 To this, GBL (3.8 g) and PGME (20.0 g) were added, and by stirring at 70° C. for 15 hours, a polyimide solution was obtained. Abnormalities such as turbidity and precipitation were not observed in any of the above-mentioned polyimide solutions, and were confirmed to be homogeneous solutions. Next, to these polyimide solutions, a 10 wt% PGME solution (0.3 g) of TETRAD-C was added, and the liquid crystal alignment agents (1) to (4) were obtained by stirring at room temperature for 30 minutes. Using the prepared liquid crystal alignment treatment agents (1) to (4), the evaluation of solvent drying speed, the evaluation of rubbing resistance, the production of liquid crystal cells, and the evaluation of the voltage holding ratio of liquid crystal cells were carried out. Various evaluations were similarly performed for Examples 5 to 13 and Comparative Examples 1 to 3. Table 1 shows the evaluation results of the solvent drying speed of the Examples and Comparative Examples, Table 2 shows the evaluation results of the rubbing resistance, and Table 3 shows the evaluation results of the voltage holding ratio of the liquid crystal cells.

<Example 5> To 1 g of the polyimide powder (A) obtained in Synthesis Example 1, GBL (6.3 g) and PGME (17.3 g) were added, and by stirring at 70° C. for 15 hours, polyimide was obtained. solution. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution. Next, to this polyimide solution, a 10 wt% PGME solution (0.5 g) of TETRAD-C was added, and by stirring at room temperature for 30 minutes, a liquid crystal aligning agent (5) was obtained.

<Examples 6 to 8> GBL (6.3 g) was added to 1 g of each of the polyimide powders (A), (B), and (C) obtained in Synthesis Example 1, Synthesis Example 2, and Synthesis Example 3. With PGME (12.5 g) and DME (5.0 g), by stirring at 70°C for 15 hours, an imide solution was obtained. Abnormalities such as turbidity and precipitation were not observed in any of the above-mentioned polyimide solutions, and were confirmed to be homogeneous solutions. Next, to these polyimide solutions, a 10 wt% PGME solution (0.3 g) of TETRAD-C was added, and the liquid crystal alignment agents (6) to (8) were obtained by stirring at room temperature for 30 minutes.

<Example 9> To 1 g of the polyimide powder (A) obtained in Synthesis Example 1, PGME (18.9 g) and EC (5.0 g) were added, and by stirring at 70°C for 15 hours, a polyimide was obtained. Amine solution. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution. Next, to these polyimide solutions, a 10 wt% PGME solution (0.3 g) of TETRAD-C was added, and by stirring at room temperature for 30 minutes, a liquid crystal aligning agent (9) was obtained.

<Examples 10 to 13> 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 To this, GBL (3.8 g), PGME (8.9 g), and CHN (8.9 g) were added, and the mixture was stirred at 70° C. for 15 hours to obtain a polyimide solution. Abnormalities such as turbidity and precipitation were not observed in any of the above-mentioned polyimide solutions, and were confirmed to be homogeneous solutions. Next, to these polyimide solutions, a 10 wt% PGME solution (0.5 g) of TETRAD-C was added, and the liquid crystal alignment agents (10) to (13) were obtained by stirring at room temperature for 30 minutes.

<Example 14> To 10 g of the polyamic acid solution (D) obtained in Synthesis Example 4, CHN (7.5 g), PGME (20.6 g), and a 10 wt% PGME solution (0.75 g) of TETRAD-C were added, By stirring at room temperature for 30 minutes, a liquid crystal aligning agent (14) was obtained. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution. Using the prepared liquid crystal alignment treatment agent (14), evaluation of solvent drying speed, evaluation of rubbing resistance, fabrication of liquid crystal display elements, and evaluation of liquid crystal alignment 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 wt% PGME solution (0.75 g) of TETRAD-C were added, By stirring at room temperature for 30 minutes, a liquid crystal aligning agent (15) was obtained. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous 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 wt% PGME solution (0.75 g) of TETRAD-C were added, By stirring at room temperature for 30 minutes, a liquid crystal aligning agent (16) was obtained. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous 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 wt% PGME solution (0.75 g) of TETRAD-C were added, By stirring at room temperature for 30 minutes, a liquid crystal aligning agent (16) was obtained. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution.

<Comparative Example 1> To 1 g of the polyimide powder (A) obtained in Synthesis Example 1, NMP (16.2 g) and BCS (7.5 g) were added, and by stirring at 70°C for 15 hours, a polyimide was obtained. Amine solution. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution. This polyimide solution is used as a liquid crystal alignment agent (17).

<Comparative Example 2> To 1 g of the polyimide powder (A) obtained in Synthesis Example 1, NMP (16.2 g) and BCS (7.5 g) were added, and by stirring at 70° C. for 15 hours, a polyimide was obtained. Amine solution. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution. Next, to these polyimide solutions, a 10 wt % NMP solution (0.3 g) of TMBIP was added, and by stirring at room temperature for 30 minutes, a liquid crystal aligning agent (18) was obtained.

<Comparative Example 3> To 1 g of the polyimide powder (A) obtained in Synthesis Example 1, NMP (16.2 g) and BCS (7.5 g) were added, and by stirring at 70° C. for 15 hours, a polyimide was obtained. Amine solution. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution. Next, to these polyimide solutions, a 10 wt % NMP solution (0.3 g) of GT401 was added, and by stirring at room temperature for 30 minutes, a liquid crystal aligning agent (19) was obtained.

<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 wt% NMP solution (0.45 g) of TETRAD-C were added, By stirring at room temperature for 30 minutes, a liquid crystal aligning agent (20) was obtained. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution.

<Comparative Example 5> To 1 g of the polyimide powder (A) obtained in Synthesis Example 1, NMP (16.2 g) and BCS (7.5 g) were added, and by stirring at 70°C for 15 hours, a polyimide was obtained. Amine solution. Abnormalities such as turbidity or precipitation were not observed in this polyimide solution, and it was confirmed that it was a homogeneous solution. Next, to these polyimide solutions, a 10 wt % NMP solution (0.5 g) of TMBIP and a 10 wt % NMP solution (0.3 g) of PTSA were added, and the liquid crystal alignment agent (21) was obtained by stirring at room temperature for 30 minutes. ).

<Evaluation of solvent drying rate> The liquid crystal aligning agents of the present invention obtained in Examples (1) to (13) and Comparative Examples (1) to (5) were spin-coated on a glass substrate with transparent electrodes, and dried. The film thickness of the coating film was 100 nm, and the time until the solvent was dried on a hot plate at 30° C. was observed.

<Evaluation of rubbing resistance> The liquid crystal aligning agents of the present invention obtained in Examples (1) to (17) and Comparative Examples (1) to (5) were spin-coated on a glass substrate with a transparent electrode, and heated at 50°C. After drying the solvent for 120 seconds on the hot plate, baking was performed on a hot plate at 120° C. for 5 minutes to form a coating film having a thickness of 100 nm. The coated film surface was rubbed with a rubbing device with a roll diameter of 120 mm, using a rayon cloth, under the conditions of a roll rotation number of 1000 rpm, a roll speed of 50 mm/sec, and a push amount of 0.3 mm to obtain a substrate with a liquid crystal alignment film. With a laser microscope set to a magnification of 100 times, randomly observe 5 places on the surface of the liquid crystal alignment film near the center of the above-mentioned substrate, and observe the friction damage and friction debris (adhesion) confirmed within the scope of about 6.5 mm square of the field of view. The average value of the amount was used to evaluate the friction resistance. The results are shown in Table 1. In addition, the evaluation criteria are as follows. Evaluation criteria ○: 20 or less friction scratches or friction chips △: 20 to 40 friction scratches or friction chips ×: 40 or more friction scratches or friction chips

[Production of Vertically Aligned Liquid Crystal Cells] The liquid crystal aligning agents of the present invention obtained in Examples (1) to (13) and Comparative Examples (1) to (3) and (5) were spin-coated on an ITO film. After drying the ITO surface of the glass substrate with transparent electrodes at 50°C for 120 seconds, it was fired in an IR oven at 120°C for 10 minutes to form a liquid crystal alignment film with a thickness of 100 nm. Next, the coating film surface was rubbed with a rubbing device with a roll diameter of 120 mm, using a rayon cloth, under the conditions of a roll rotation number of 1000 rpm, a roll speed of 50 mm/sec, and a pressing amount of 0.3 mm, to obtain a liquid crystal alignment film attached. substrate. Prepare two above-mentioned substrates, spread a 4 μm bead spacer on the liquid crystal alignment film of one of the substrates, and then apply a sealant (XN-1500T, manufactured by Kyoritsu Chemical). Next, after bonding the other substrate so that the liquid crystal alignment film faces face each other and the alignment direction becomes 180°, the sealing compound is thermally cured at 120° C. for 90 minutes to produce an empty cell. Negative liquid crystal (Merck company make, MLC-3022) was injected|thrown-in to this empty cell by the pressure reduction injection method, and the liquid crystal cell was produced. After the liquid crystal cell was fabricated, the isotropic phase treatment was performed at 120°C for 1 hour, and the cell was observed with a polarizing microscope. There was no misalignment such as light leakage or domain generation in any liquid crystal cell, and it was confirmed that a uniform liquid crystal alignment could be obtained. .

<Evaluation of the voltage retention rate of the liquid crystal cell> For the liquid crystal cell produced above, a voltage of 1V was applied for 60 μs at a temperature of 60°C, and the voltage after 1667 ms was measured, and how much the voltage could be maintained was calculated as the voltage retention rate. For the measurement system, a VHR-1 voltage holding ratio measuring device manufactured by TOYO Corporation was used. Measured at the settings of Voltage: ±1V, Pulse Width: 60μs, and Flame Period: 1667ms.

[產業上之可利用性]

[Industrial Availability]

The liquid crystal display element using the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention can be applied to display elements of various liquid crystal modes. Furthermore, these elements can also be used for liquid crystal displays for display purposes, and dimming windows or light shutters for controlling the transmission and blocking of light.

Claims (6)

A liquid crystal alignment agent, which contains the following (A) components; (B) components; and (C) components; (A) components: selected from polyimide precursors, and by the polyimide precursors A polymer of at least one of the polyimide groups obtained by the imidization reaction; (B) component: the following formula (N-2-1), (N-2-2) or (N- 2-4) The compound represented by (in the formula, X each independently represents a single bond, methylidene, ethylidene, propylidene, butylene, pentylene, hexylene, Y represents methylene, ethylidene , any one of propylidene, vinylidene, oxy, and thio groups, Z represents cyclopentanediyl, cyclohexanediyl, or norbornediyl); (C) component: selected from the following formula (1 )~(8) (in formulae (1)~(4) and (8), R ¹¹ ~R ¹⁶ and R ²⁰ ~R ²¹ each independently represent a linear or branched alkyl group with 1 to 4 carbon atoms, formula In (5) and (6), R ¹⁷ to R ¹⁹ represent 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 grouped together,

H ₃ C-CH(OH)-CH ₂ -OR ₁₁ (1) HO-CH ₂ -CH ₂ -OR ₁₂ (2) R ₁₃ -O-CH ₂ -CH ₂ -OR ₁₄ (3) H ₃ CCOO- R ₁₅ -OR ₁₆ (4) HO-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -OR ₁₇ (5) R ₁₈ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -OR ₁₉ (6)

R ₂₀ -CO-R ₂₁ (8) . The liquid crystal aligning agent according to claim 1, wherein in 100 wt % of the total solvent content of the liquid crystal aligning agent, the component (C) is 70 wt % or more. The liquid crystal aligning agent according to claim 1 or 2, wherein the component (A) is at least one tetracarboxylic acid selected from the group consisting of tetracarboxylic dianhydride, tetracarboxylic diester, and tetracarboxylic diester dihalide. A polymer obtained by reacting a derivative with a diamine, the aforementioned tetracarboxylic acid derivative contains at least one selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, a cyclohexane ring structure, and a benzene ring structure compound of. A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of claims 1 to 3. A method for manufacturing a liquid crystal alignment film, comprising the following steps: coating the liquid crystal alignment agent as claimed in any one of claims 1 to 3 on a substrate, forming a coating film, and the coating film not being in contact with a liquid crystal layer In the state of being in contact with the liquid crystal layer, the step of irradiating the coating film with light. A liquid crystal display element comprising: the liquid crystal alignment film of claim 4; or the liquid crystal alignment film obtained by the manufacturing method of claim 5.